| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Shared application/kernel submission and completion ring pairs, for |
| * supporting fast/efficient IO. |
| * |
| * A note on the read/write ordering memory barriers that are matched between |
| * the application and kernel side. |
| * |
| * After the application reads the CQ ring tail, it must use an |
| * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses |
| * before writing the tail (using smp_load_acquire to read the tail will |
| * do). It also needs a smp_mb() before updating CQ head (ordering the |
| * entry load(s) with the head store), pairing with an implicit barrier |
| * through a control-dependency in io_get_cqring (smp_store_release to |
| * store head will do). Failure to do so could lead to reading invalid |
| * CQ entries. |
| * |
| * Likewise, the application must use an appropriate smp_wmb() before |
| * writing the SQ tail (ordering SQ entry stores with the tail store), |
| * which pairs with smp_load_acquire in io_get_sqring (smp_store_release |
| * to store the tail will do). And it needs a barrier ordering the SQ |
| * head load before writing new SQ entries (smp_load_acquire to read |
| * head will do). |
| * |
| * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application |
| * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after* |
| * updating the SQ tail; a full memory barrier smp_mb() is needed |
| * between. |
| * |
| * Also see the examples in the liburing library: |
| * |
| * git://git.kernel.dk/liburing |
| * |
| * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens |
| * from data shared between the kernel and application. This is done both |
| * for ordering purposes, but also to ensure that once a value is loaded from |
| * data that the application could potentially modify, it remains stable. |
| * |
| * Copyright (C) 2018-2019 Jens Axboe |
| * Copyright (c) 2018-2019 Christoph Hellwig |
| */ |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/errno.h> |
| #include <linux/syscalls.h> |
| #include <linux/compat.h> |
| #include <net/compat.h> |
| #include <linux/refcount.h> |
| #include <linux/uio.h> |
| #include <linux/bits.h> |
| |
| #include <linux/sched/signal.h> |
| #include <linux/fs.h> |
| #include <linux/file.h> |
| #include <linux/fdtable.h> |
| #include <linux/mm.h> |
| #include <linux/mman.h> |
| #include <linux/percpu.h> |
| #include <linux/slab.h> |
| #include <linux/kthread.h> |
| #include <linux/blkdev.h> |
| #include <linux/bvec.h> |
| #include <linux/net.h> |
| #include <net/sock.h> |
| #include <net/af_unix.h> |
| #include <net/scm.h> |
| #include <linux/anon_inodes.h> |
| #include <linux/sched/mm.h> |
| #include <linux/uaccess.h> |
| #include <linux/nospec.h> |
| #include <linux/sizes.h> |
| #include <linux/hugetlb.h> |
| #include <linux/highmem.h> |
| #include <linux/namei.h> |
| #include <linux/fsnotify.h> |
| #include <linux/fadvise.h> |
| #include <linux/eventpoll.h> |
| #include <linux/fs_struct.h> |
| #include <linux/splice.h> |
| #include <linux/task_work.h> |
| #include <linux/pagemap.h> |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/io_uring.h> |
| |
| #include <uapi/linux/io_uring.h> |
| |
| #include "internal.h" |
| #include "io-wq.h" |
| |
| #define IORING_MAX_ENTRIES 32768 |
| #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) |
| |
| /* |
| * Shift of 9 is 512 entries, or exactly one page on 64-bit archs |
| */ |
| #define IORING_FILE_TABLE_SHIFT 9 |
| #define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT) |
| #define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1) |
| #define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE) |
| |
| struct io_uring { |
| u32 head ____cacheline_aligned_in_smp; |
| u32 tail ____cacheline_aligned_in_smp; |
| }; |
| |
| /* |
| * This data is shared with the application through the mmap at offsets |
| * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING. |
| * |
| * The offsets to the member fields are published through struct |
| * io_sqring_offsets when calling io_uring_setup. |
| */ |
| struct io_rings { |
| /* |
| * Head and tail offsets into the ring; the offsets need to be |
| * masked to get valid indices. |
| * |
| * The kernel controls head of the sq ring and the tail of the cq ring, |
| * and the application controls tail of the sq ring and the head of the |
| * cq ring. |
| */ |
| struct io_uring sq, cq; |
| /* |
| * Bitmasks to apply to head and tail offsets (constant, equals |
| * ring_entries - 1) |
| */ |
| u32 sq_ring_mask, cq_ring_mask; |
| /* Ring sizes (constant, power of 2) */ |
| u32 sq_ring_entries, cq_ring_entries; |
| /* |
| * Number of invalid entries dropped by the kernel due to |
| * invalid index stored in array |
| * |
| * Written by the kernel, shouldn't be modified by the |
| * application (i.e. get number of "new events" by comparing to |
| * cached value). |
| * |
| * After a new SQ head value was read by the application this |
| * counter includes all submissions that were dropped reaching |
| * the new SQ head (and possibly more). |
| */ |
| u32 sq_dropped; |
| /* |
| * Runtime SQ flags |
| * |
| * Written by the kernel, shouldn't be modified by the |
| * application. |
| * |
| * The application needs a full memory barrier before checking |
| * for IORING_SQ_NEED_WAKEUP after updating the sq tail. |
| */ |
| u32 sq_flags; |
| /* |
| * Runtime CQ flags |
| * |
| * Written by the application, shouldn't be modified by the |
| * kernel. |
| */ |
| u32 cq_flags; |
| /* |
| * Number of completion events lost because the queue was full; |
| * this should be avoided by the application by making sure |
| * there are not more requests pending than there is space in |
| * the completion queue. |
| * |
| * Written by the kernel, shouldn't be modified by the |
| * application (i.e. get number of "new events" by comparing to |
| * cached value). |
| * |
| * As completion events come in out of order this counter is not |
| * ordered with any other data. |
| */ |
| u32 cq_overflow; |
| /* |
| * Ring buffer of completion events. |
| * |
| * The kernel writes completion events fresh every time they are |
| * produced, so the application is allowed to modify pending |
| * entries. |
| */ |
| struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp; |
| }; |
| |
| struct io_mapped_ubuf { |
| u64 ubuf; |
| size_t len; |
| struct bio_vec *bvec; |
| unsigned int nr_bvecs; |
| }; |
| |
| struct fixed_file_table { |
| struct file **files; |
| }; |
| |
| struct fixed_file_ref_node { |
| struct percpu_ref refs; |
| struct list_head node; |
| struct list_head file_list; |
| struct fixed_file_data *file_data; |
| struct llist_node llist; |
| }; |
| |
| struct fixed_file_data { |
| struct fixed_file_table *table; |
| struct io_ring_ctx *ctx; |
| |
| struct percpu_ref *cur_refs; |
| struct percpu_ref refs; |
| struct completion done; |
| struct list_head ref_list; |
| spinlock_t lock; |
| }; |
| |
| struct io_buffer { |
| struct list_head list; |
| __u64 addr; |
| __s32 len; |
| __u16 bid; |
| }; |
| |
| struct io_ring_ctx { |
| struct { |
| struct percpu_ref refs; |
| } ____cacheline_aligned_in_smp; |
| |
| struct { |
| unsigned int flags; |
| unsigned int compat: 1; |
| unsigned int limit_mem: 1; |
| unsigned int cq_overflow_flushed: 1; |
| unsigned int drain_next: 1; |
| unsigned int eventfd_async: 1; |
| |
| /* |
| * Ring buffer of indices into array of io_uring_sqe, which is |
| * mmapped by the application using the IORING_OFF_SQES offset. |
| * |
| * This indirection could e.g. be used to assign fixed |
| * io_uring_sqe entries to operations and only submit them to |
| * the queue when needed. |
| * |
| * The kernel modifies neither the indices array nor the entries |
| * array. |
| */ |
| u32 *sq_array; |
| unsigned cached_sq_head; |
| unsigned sq_entries; |
| unsigned sq_mask; |
| unsigned sq_thread_idle; |
| unsigned cached_sq_dropped; |
| atomic_t cached_cq_overflow; |
| unsigned long sq_check_overflow; |
| |
| struct list_head defer_list; |
| struct list_head timeout_list; |
| struct list_head cq_overflow_list; |
| |
| wait_queue_head_t inflight_wait; |
| struct io_uring_sqe *sq_sqes; |
| } ____cacheline_aligned_in_smp; |
| |
| struct io_rings *rings; |
| |
| /* IO offload */ |
| struct io_wq *io_wq; |
| struct task_struct *sqo_thread; /* if using sq thread polling */ |
| struct mm_struct *sqo_mm; |
| wait_queue_head_t sqo_wait; |
| |
| /* |
| * If used, fixed file set. Writers must ensure that ->refs is dead, |
| * readers must ensure that ->refs is alive as long as the file* is |
| * used. Only updated through io_uring_register(2). |
| */ |
| struct fixed_file_data *file_data; |
| unsigned nr_user_files; |
| int ring_fd; |
| struct file *ring_file; |
| |
| /* if used, fixed mapped user buffers */ |
| unsigned nr_user_bufs; |
| struct io_mapped_ubuf *user_bufs; |
| |
| struct user_struct *user; |
| |
| const struct cred *creds; |
| |
| struct completion ref_comp; |
| struct completion sq_thread_comp; |
| |
| /* if all else fails... */ |
| struct io_kiocb *fallback_req; |
| |
| #if defined(CONFIG_UNIX) |
| struct socket *ring_sock; |
| #endif |
| |
| struct idr io_buffer_idr; |
| |
| struct idr personality_idr; |
| |
| struct { |
| unsigned cached_cq_tail; |
| unsigned cq_entries; |
| unsigned cq_mask; |
| atomic_t cq_timeouts; |
| unsigned long cq_check_overflow; |
| struct wait_queue_head cq_wait; |
| struct fasync_struct *cq_fasync; |
| struct eventfd_ctx *cq_ev_fd; |
| } ____cacheline_aligned_in_smp; |
| |
| struct { |
| struct mutex uring_lock; |
| wait_queue_head_t wait; |
| } ____cacheline_aligned_in_smp; |
| |
| struct { |
| spinlock_t completion_lock; |
| |
| /* |
| * ->iopoll_list is protected by the ctx->uring_lock for |
| * io_uring instances that don't use IORING_SETUP_SQPOLL. |
| * For SQPOLL, only the single threaded io_sq_thread() will |
| * manipulate the list, hence no extra locking is needed there. |
| */ |
| struct list_head iopoll_list; |
| struct hlist_head *cancel_hash; |
| unsigned cancel_hash_bits; |
| bool poll_multi_file; |
| |
| spinlock_t inflight_lock; |
| struct list_head inflight_list; |
| } ____cacheline_aligned_in_smp; |
| |
| struct delayed_work file_put_work; |
| struct llist_head file_put_llist; |
| |
| struct work_struct exit_work; |
| }; |
| |
| /* |
| * First field must be the file pointer in all the |
| * iocb unions! See also 'struct kiocb' in <linux/fs.h> |
| */ |
| struct io_poll_iocb { |
| struct file *file; |
| union { |
| struct wait_queue_head *head; |
| u64 addr; |
| }; |
| __poll_t events; |
| bool done; |
| bool canceled; |
| struct wait_queue_entry wait; |
| }; |
| |
| struct io_close { |
| struct file *file; |
| struct file *put_file; |
| int fd; |
| }; |
| |
| struct io_timeout_data { |
| struct io_kiocb *req; |
| struct hrtimer timer; |
| struct timespec64 ts; |
| enum hrtimer_mode mode; |
| }; |
| |
| struct io_accept { |
| struct file *file; |
| struct sockaddr __user *addr; |
| int __user *addr_len; |
| int flags; |
| unsigned long nofile; |
| }; |
| |
| struct io_sync { |
| struct file *file; |
| loff_t len; |
| loff_t off; |
| int flags; |
| int mode; |
| }; |
| |
| struct io_cancel { |
| struct file *file; |
| u64 addr; |
| }; |
| |
| struct io_timeout { |
| struct file *file; |
| u64 addr; |
| int flags; |
| u32 off; |
| u32 target_seq; |
| struct list_head list; |
| }; |
| |
| struct io_rw { |
| /* NOTE: kiocb has the file as the first member, so don't do it here */ |
| struct kiocb kiocb; |
| u64 addr; |
| u64 len; |
| }; |
| |
| struct io_connect { |
| struct file *file; |
| struct sockaddr __user *addr; |
| int addr_len; |
| }; |
| |
| struct io_sr_msg { |
| struct file *file; |
| union { |
| struct user_msghdr __user *umsg; |
| void __user *buf; |
| }; |
| int msg_flags; |
| int bgid; |
| size_t len; |
| struct io_buffer *kbuf; |
| }; |
| |
| struct io_open { |
| struct file *file; |
| int dfd; |
| struct filename *filename; |
| struct open_how how; |
| unsigned long nofile; |
| }; |
| |
| struct io_files_update { |
| struct file *file; |
| u64 arg; |
| u32 nr_args; |
| u32 offset; |
| }; |
| |
| struct io_fadvise { |
| struct file *file; |
| u64 offset; |
| u32 len; |
| u32 advice; |
| }; |
| |
| struct io_madvise { |
| struct file *file; |
| u64 addr; |
| u32 len; |
| u32 advice; |
| }; |
| |
| struct io_epoll { |
| struct file *file; |
| int epfd; |
| int op; |
| int fd; |
| struct epoll_event event; |
| }; |
| |
| struct io_splice { |
| struct file *file_out; |
| struct file *file_in; |
| loff_t off_out; |
| loff_t off_in; |
| u64 len; |
| unsigned int flags; |
| }; |
| |
| struct io_provide_buf { |
| struct file *file; |
| __u64 addr; |
| __s32 len; |
| __u32 bgid; |
| __u16 nbufs; |
| __u16 bid; |
| }; |
| |
| struct io_statx { |
| struct file *file; |
| int dfd; |
| unsigned int mask; |
| unsigned int flags; |
| const char __user *filename; |
| struct statx __user *buffer; |
| }; |
| |
| struct io_completion { |
| struct file *file; |
| struct list_head list; |
| int cflags; |
| }; |
| |
| struct io_async_connect { |
| struct sockaddr_storage address; |
| }; |
| |
| struct io_async_msghdr { |
| struct iovec fast_iov[UIO_FASTIOV]; |
| struct iovec *iov; |
| struct sockaddr __user *uaddr; |
| struct msghdr msg; |
| struct sockaddr_storage addr; |
| }; |
| |
| struct io_async_rw { |
| struct iovec fast_iov[UIO_FASTIOV]; |
| const struct iovec *free_iovec; |
| struct iov_iter iter; |
| size_t bytes_done; |
| struct wait_page_queue wpq; |
| }; |
| |
| struct io_async_ctx { |
| union { |
| struct io_async_rw rw; |
| struct io_async_msghdr msg; |
| struct io_async_connect connect; |
| struct io_timeout_data timeout; |
| }; |
| }; |
| |
| enum { |
| REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT, |
| REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT, |
| REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT, |
| REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT, |
| REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT, |
| REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT, |
| |
| REQ_F_LINK_HEAD_BIT, |
| REQ_F_FAIL_LINK_BIT, |
| REQ_F_INFLIGHT_BIT, |
| REQ_F_CUR_POS_BIT, |
| REQ_F_NOWAIT_BIT, |
| REQ_F_LINK_TIMEOUT_BIT, |
| REQ_F_ISREG_BIT, |
| REQ_F_COMP_LOCKED_BIT, |
| REQ_F_NEED_CLEANUP_BIT, |
| REQ_F_POLLED_BIT, |
| REQ_F_BUFFER_SELECTED_BIT, |
| REQ_F_NO_FILE_TABLE_BIT, |
| REQ_F_WORK_INITIALIZED_BIT, |
| REQ_F_TASK_PINNED_BIT, |
| |
| /* not a real bit, just to check we're not overflowing the space */ |
| __REQ_F_LAST_BIT, |
| }; |
| |
| enum { |
| /* ctx owns file */ |
| REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT), |
| /* drain existing IO first */ |
| REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT), |
| /* linked sqes */ |
| REQ_F_LINK = BIT(REQ_F_LINK_BIT), |
| /* doesn't sever on completion < 0 */ |
| REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT), |
| /* IOSQE_ASYNC */ |
| REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT), |
| /* IOSQE_BUFFER_SELECT */ |
| REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT), |
| |
| /* head of a link */ |
| REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT), |
| /* fail rest of links */ |
| REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT), |
| /* on inflight list */ |
| REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT), |
| /* read/write uses file position */ |
| REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT), |
| /* must not punt to workers */ |
| REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT), |
| /* has linked timeout */ |
| REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT), |
| /* regular file */ |
| REQ_F_ISREG = BIT(REQ_F_ISREG_BIT), |
| /* completion under lock */ |
| REQ_F_COMP_LOCKED = BIT(REQ_F_COMP_LOCKED_BIT), |
| /* needs cleanup */ |
| REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT), |
| /* already went through poll handler */ |
| REQ_F_POLLED = BIT(REQ_F_POLLED_BIT), |
| /* buffer already selected */ |
| REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT), |
| /* doesn't need file table for this request */ |
| REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT), |
| /* io_wq_work is initialized */ |
| REQ_F_WORK_INITIALIZED = BIT(REQ_F_WORK_INITIALIZED_BIT), |
| /* req->task is refcounted */ |
| REQ_F_TASK_PINNED = BIT(REQ_F_TASK_PINNED_BIT), |
| }; |
| |
| struct async_poll { |
| struct io_poll_iocb poll; |
| struct io_poll_iocb *double_poll; |
| }; |
| |
| /* |
| * NOTE! Each of the iocb union members has the file pointer |
| * as the first entry in their struct definition. So you can |
| * access the file pointer through any of the sub-structs, |
| * or directly as just 'ki_filp' in this struct. |
| */ |
| struct io_kiocb { |
| union { |
| struct file *file; |
| struct io_rw rw; |
| struct io_poll_iocb poll; |
| struct io_accept accept; |
| struct io_sync sync; |
| struct io_cancel cancel; |
| struct io_timeout timeout; |
| struct io_connect connect; |
| struct io_sr_msg sr_msg; |
| struct io_open open; |
| struct io_close close; |
| struct io_files_update files_update; |
| struct io_fadvise fadvise; |
| struct io_madvise madvise; |
| struct io_epoll epoll; |
| struct io_splice splice; |
| struct io_provide_buf pbuf; |
| struct io_statx statx; |
| /* use only after cleaning per-op data, see io_clean_op() */ |
| struct io_completion compl; |
| }; |
| |
| struct io_async_ctx *io; |
| u8 opcode; |
| /* polled IO has completed */ |
| u8 iopoll_completed; |
| |
| u16 buf_index; |
| u32 result; |
| |
| struct io_ring_ctx *ctx; |
| unsigned int flags; |
| refcount_t refs; |
| struct task_struct *task; |
| u64 user_data; |
| |
| struct list_head link_list; |
| |
| /* |
| * 1. used with ctx->iopoll_list with reads/writes |
| * 2. to track reqs with ->files (see io_op_def::file_table) |
| */ |
| struct list_head inflight_entry; |
| |
| struct percpu_ref *fixed_file_refs; |
| struct callback_head task_work; |
| /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */ |
| struct hlist_node hash_node; |
| struct async_poll *apoll; |
| struct io_wq_work work; |
| }; |
| |
| struct io_defer_entry { |
| struct list_head list; |
| struct io_kiocb *req; |
| u32 seq; |
| }; |
| |
| #define IO_IOPOLL_BATCH 8 |
| |
| struct io_comp_state { |
| unsigned int nr; |
| struct list_head list; |
| struct io_ring_ctx *ctx; |
| }; |
| |
| struct io_submit_state { |
| struct blk_plug plug; |
| |
| /* |
| * io_kiocb alloc cache |
| */ |
| void *reqs[IO_IOPOLL_BATCH]; |
| unsigned int free_reqs; |
| |
| /* |
| * Batch completion logic |
| */ |
| struct io_comp_state comp; |
| |
| /* |
| * File reference cache |
| */ |
| struct file *file; |
| unsigned int fd; |
| unsigned int has_refs; |
| unsigned int ios_left; |
| }; |
| |
| struct io_op_def { |
| /* needs req->io allocated for deferral/async */ |
| unsigned async_ctx : 1; |
| /* needs current->mm setup, does mm access */ |
| unsigned needs_mm : 1; |
| /* needs req->file assigned */ |
| unsigned needs_file : 1; |
| /* don't fail if file grab fails */ |
| unsigned needs_file_no_error : 1; |
| /* hash wq insertion if file is a regular file */ |
| unsigned hash_reg_file : 1; |
| /* unbound wq insertion if file is a non-regular file */ |
| unsigned unbound_nonreg_file : 1; |
| /* opcode is not supported by this kernel */ |
| unsigned not_supported : 1; |
| /* needs file table */ |
| unsigned file_table : 1; |
| /* needs ->fs */ |
| unsigned needs_fs : 1; |
| /* set if opcode supports polled "wait" */ |
| unsigned pollin : 1; |
| unsigned pollout : 1; |
| /* op supports buffer selection */ |
| unsigned buffer_select : 1; |
| unsigned needs_fsize : 1; |
| }; |
| |
| static const struct io_op_def io_op_defs[] = { |
| [IORING_OP_NOP] = {}, |
| [IORING_OP_READV] = { |
| .async_ctx = 1, |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollin = 1, |
| .buffer_select = 1, |
| }, |
| [IORING_OP_WRITEV] = { |
| .async_ctx = 1, |
| .needs_mm = 1, |
| .needs_file = 1, |
| .hash_reg_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollout = 1, |
| .needs_fsize = 1, |
| }, |
| [IORING_OP_FSYNC] = { |
| .needs_file = 1, |
| }, |
| [IORING_OP_READ_FIXED] = { |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollin = 1, |
| }, |
| [IORING_OP_WRITE_FIXED] = { |
| .needs_file = 1, |
| .hash_reg_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollout = 1, |
| .needs_fsize = 1, |
| }, |
| [IORING_OP_POLL_ADD] = { |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| }, |
| [IORING_OP_POLL_REMOVE] = {}, |
| [IORING_OP_SYNC_FILE_RANGE] = { |
| .needs_file = 1, |
| }, |
| [IORING_OP_SENDMSG] = { |
| .async_ctx = 1, |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .needs_fs = 1, |
| .pollout = 1, |
| }, |
| [IORING_OP_RECVMSG] = { |
| .async_ctx = 1, |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .needs_fs = 1, |
| .pollin = 1, |
| .buffer_select = 1, |
| }, |
| [IORING_OP_TIMEOUT] = { |
| .async_ctx = 1, |
| .needs_mm = 1, |
| }, |
| [IORING_OP_TIMEOUT_REMOVE] = {}, |
| [IORING_OP_ACCEPT] = { |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .file_table = 1, |
| .pollin = 1, |
| }, |
| [IORING_OP_ASYNC_CANCEL] = {}, |
| [IORING_OP_LINK_TIMEOUT] = { |
| .async_ctx = 1, |
| .needs_mm = 1, |
| }, |
| [IORING_OP_CONNECT] = { |
| .async_ctx = 1, |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollout = 1, |
| }, |
| [IORING_OP_FALLOCATE] = { |
| .needs_file = 1, |
| .needs_fsize = 1, |
| }, |
| [IORING_OP_OPENAT] = { |
| .file_table = 1, |
| .needs_fs = 1, |
| }, |
| [IORING_OP_CLOSE] = { |
| .needs_file = 1, |
| .needs_file_no_error = 1, |
| .file_table = 1, |
| }, |
| [IORING_OP_FILES_UPDATE] = { |
| .needs_mm = 1, |
| .file_table = 1, |
| }, |
| [IORING_OP_STATX] = { |
| .needs_mm = 1, |
| .needs_fs = 1, |
| .file_table = 1, |
| }, |
| [IORING_OP_READ] = { |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollin = 1, |
| .buffer_select = 1, |
| }, |
| [IORING_OP_WRITE] = { |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollout = 1, |
| .needs_fsize = 1, |
| }, |
| [IORING_OP_FADVISE] = { |
| .needs_file = 1, |
| }, |
| [IORING_OP_MADVISE] = { |
| .needs_mm = 1, |
| }, |
| [IORING_OP_SEND] = { |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollout = 1, |
| }, |
| [IORING_OP_RECV] = { |
| .needs_mm = 1, |
| .needs_file = 1, |
| .unbound_nonreg_file = 1, |
| .pollin = 1, |
| .buffer_select = 1, |
| }, |
| [IORING_OP_OPENAT2] = { |
| .file_table = 1, |
| .needs_fs = 1, |
| }, |
| [IORING_OP_EPOLL_CTL] = { |
| .unbound_nonreg_file = 1, |
| .file_table = 1, |
| }, |
| [IORING_OP_SPLICE] = { |
| .needs_file = 1, |
| .hash_reg_file = 1, |
| .unbound_nonreg_file = 1, |
| }, |
| [IORING_OP_PROVIDE_BUFFERS] = {}, |
| [IORING_OP_REMOVE_BUFFERS] = {}, |
| [IORING_OP_TEE] = { |
| .needs_file = 1, |
| .hash_reg_file = 1, |
| .unbound_nonreg_file = 1, |
| }, |
| }; |
| |
| enum io_mem_account { |
| ACCT_LOCKED, |
| ACCT_PINNED, |
| }; |
| |
| static void __io_complete_rw(struct io_kiocb *req, long res, long res2, |
| struct io_comp_state *cs); |
| static void io_cqring_fill_event(struct io_kiocb *req, long res); |
| static void io_put_req(struct io_kiocb *req); |
| static void io_double_put_req(struct io_kiocb *req); |
| static void __io_double_put_req(struct io_kiocb *req); |
| static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req); |
| static void __io_queue_linked_timeout(struct io_kiocb *req); |
| static void io_queue_linked_timeout(struct io_kiocb *req); |
| static int __io_sqe_files_update(struct io_ring_ctx *ctx, |
| struct io_uring_files_update *ip, |
| unsigned nr_args); |
| static int io_prep_work_files(struct io_kiocb *req); |
| static void __io_clean_op(struct io_kiocb *req); |
| static int io_file_get(struct io_submit_state *state, struct io_kiocb *req, |
| int fd, struct file **out_file, bool fixed); |
| static void __io_queue_sqe(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe, |
| struct io_comp_state *cs); |
| static void io_file_put_work(struct work_struct *work); |
| |
| static ssize_t io_import_iovec(int rw, struct io_kiocb *req, |
| struct iovec **iovec, struct iov_iter *iter, |
| bool needs_lock); |
| static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, |
| const struct iovec *fast_iov, |
| struct iov_iter *iter, bool force); |
| |
| static struct kmem_cache *req_cachep; |
| |
| static const struct file_operations io_uring_fops; |
| |
| struct sock *io_uring_get_socket(struct file *file) |
| { |
| #if defined(CONFIG_UNIX) |
| if (file->f_op == &io_uring_fops) { |
| struct io_ring_ctx *ctx = file->private_data; |
| |
| return ctx->ring_sock->sk; |
| } |
| #endif |
| return NULL; |
| } |
| EXPORT_SYMBOL(io_uring_get_socket); |
| |
| static void io_get_req_task(struct io_kiocb *req) |
| { |
| if (req->flags & REQ_F_TASK_PINNED) |
| return; |
| get_task_struct(req->task); |
| req->flags |= REQ_F_TASK_PINNED; |
| } |
| |
| static inline void io_clean_op(struct io_kiocb *req) |
| { |
| if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED | |
| REQ_F_INFLIGHT)) |
| __io_clean_op(req); |
| } |
| |
| /* not idempotent -- it doesn't clear REQ_F_TASK_PINNED */ |
| static void __io_put_req_task(struct io_kiocb *req) |
| { |
| if (req->flags & REQ_F_TASK_PINNED) |
| put_task_struct(req->task); |
| } |
| |
| static void io_sq_thread_drop_mm(void) |
| { |
| struct mm_struct *mm = current->mm; |
| |
| if (mm) { |
| kthread_unuse_mm(mm); |
| mmput(mm); |
| } |
| } |
| |
| static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx) |
| { |
| if (!current->mm) { |
| if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL) || |
| !mmget_not_zero(ctx->sqo_mm))) |
| return -EFAULT; |
| kthread_use_mm(ctx->sqo_mm); |
| } |
| |
| return 0; |
| } |
| |
| static int io_sq_thread_acquire_mm(struct io_ring_ctx *ctx, |
| struct io_kiocb *req) |
| { |
| if (!io_op_defs[req->opcode].needs_mm) |
| return 0; |
| return __io_sq_thread_acquire_mm(ctx); |
| } |
| |
| static inline void req_set_fail_links(struct io_kiocb *req) |
| { |
| if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK) |
| req->flags |= REQ_F_FAIL_LINK; |
| } |
| |
| /* |
| * Note: must call io_req_init_async() for the first time you |
| * touch any members of io_wq_work. |
| */ |
| static inline void io_req_init_async(struct io_kiocb *req) |
| { |
| if (req->flags & REQ_F_WORK_INITIALIZED) |
| return; |
| |
| memset(&req->work, 0, sizeof(req->work)); |
| req->flags |= REQ_F_WORK_INITIALIZED; |
| } |
| |
| static inline bool io_async_submit(struct io_ring_ctx *ctx) |
| { |
| return ctx->flags & IORING_SETUP_SQPOLL; |
| } |
| |
| static void io_ring_ctx_ref_free(struct percpu_ref *ref) |
| { |
| struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); |
| |
| complete(&ctx->ref_comp); |
| } |
| |
| static inline bool io_is_timeout_noseq(struct io_kiocb *req) |
| { |
| return !req->timeout.off; |
| } |
| |
| static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) |
| { |
| struct io_ring_ctx *ctx; |
| int hash_bits; |
| |
| ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); |
| if (!ctx) |
| return NULL; |
| |
| ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL); |
| if (!ctx->fallback_req) |
| goto err; |
| |
| /* |
| * Use 5 bits less than the max cq entries, that should give us around |
| * 32 entries per hash list if totally full and uniformly spread. |
| */ |
| hash_bits = ilog2(p->cq_entries); |
| hash_bits -= 5; |
| if (hash_bits <= 0) |
| hash_bits = 1; |
| ctx->cancel_hash_bits = hash_bits; |
| ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head), |
| GFP_KERNEL); |
| if (!ctx->cancel_hash) |
| goto err; |
| __hash_init(ctx->cancel_hash, 1U << hash_bits); |
| |
| if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, |
| PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) |
| goto err; |
| |
| ctx->flags = p->flags; |
| init_waitqueue_head(&ctx->sqo_wait); |
| init_waitqueue_head(&ctx->cq_wait); |
| INIT_LIST_HEAD(&ctx->cq_overflow_list); |
| init_completion(&ctx->ref_comp); |
| init_completion(&ctx->sq_thread_comp); |
| idr_init(&ctx->io_buffer_idr); |
| idr_init(&ctx->personality_idr); |
| mutex_init(&ctx->uring_lock); |
| init_waitqueue_head(&ctx->wait); |
| spin_lock_init(&ctx->completion_lock); |
| INIT_LIST_HEAD(&ctx->iopoll_list); |
| INIT_LIST_HEAD(&ctx->defer_list); |
| INIT_LIST_HEAD(&ctx->timeout_list); |
| init_waitqueue_head(&ctx->inflight_wait); |
| spin_lock_init(&ctx->inflight_lock); |
| INIT_LIST_HEAD(&ctx->inflight_list); |
| INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work); |
| init_llist_head(&ctx->file_put_llist); |
| return ctx; |
| err: |
| if (ctx->fallback_req) |
| kmem_cache_free(req_cachep, ctx->fallback_req); |
| kfree(ctx->cancel_hash); |
| kfree(ctx); |
| return NULL; |
| } |
| |
| static bool req_need_defer(struct io_kiocb *req, u32 seq) |
| { |
| if (unlikely(req->flags & REQ_F_IO_DRAIN)) { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| return seq != ctx->cached_cq_tail |
| + atomic_read(&ctx->cached_cq_overflow); |
| } |
| |
| return false; |
| } |
| |
| static void __io_commit_cqring(struct io_ring_ctx *ctx) |
| { |
| struct io_rings *rings = ctx->rings; |
| |
| /* order cqe stores with ring update */ |
| smp_store_release(&rings->cq.tail, ctx->cached_cq_tail); |
| |
| if (wq_has_sleeper(&ctx->cq_wait)) { |
| wake_up_interruptible(&ctx->cq_wait); |
| kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); |
| } |
| } |
| |
| /* |
| * Returns true if we need to defer file table putting. This can only happen |
| * from the error path with REQ_F_COMP_LOCKED set. |
| */ |
| static bool io_req_clean_work(struct io_kiocb *req) |
| { |
| if (!(req->flags & REQ_F_WORK_INITIALIZED)) |
| return false; |
| |
| req->flags &= ~REQ_F_WORK_INITIALIZED; |
| |
| if (req->work.mm) { |
| mmdrop(req->work.mm); |
| req->work.mm = NULL; |
| } |
| if (req->work.creds) { |
| put_cred(req->work.creds); |
| req->work.creds = NULL; |
| } |
| if (req->work.fs) { |
| struct fs_struct *fs = req->work.fs; |
| |
| if (req->flags & REQ_F_COMP_LOCKED) |
| return true; |
| |
| spin_lock(&req->work.fs->lock); |
| if (--fs->users) |
| fs = NULL; |
| spin_unlock(&req->work.fs->lock); |
| if (fs) |
| free_fs_struct(fs); |
| req->work.fs = NULL; |
| } |
| |
| return false; |
| } |
| |
| static void io_prep_async_work(struct io_kiocb *req) |
| { |
| const struct io_op_def *def = &io_op_defs[req->opcode]; |
| |
| io_req_init_async(req); |
| |
| if (req->flags & REQ_F_ISREG) { |
| if (def->hash_reg_file || (req->ctx->flags & IORING_SETUP_IOPOLL)) |
| io_wq_hash_work(&req->work, file_inode(req->file)); |
| } else { |
| if (def->unbound_nonreg_file) |
| req->work.flags |= IO_WQ_WORK_UNBOUND; |
| } |
| if (!req->work.mm && def->needs_mm) { |
| mmgrab(current->mm); |
| req->work.mm = current->mm; |
| } |
| if (!req->work.creds) |
| req->work.creds = get_current_cred(); |
| if (!req->work.fs && def->needs_fs) { |
| spin_lock(¤t->fs->lock); |
| if (!current->fs->in_exec) { |
| req->work.fs = current->fs; |
| req->work.fs->users++; |
| } else { |
| req->work.flags |= IO_WQ_WORK_CANCEL; |
| } |
| spin_unlock(¤t->fs->lock); |
| } |
| if (def->needs_fsize) |
| req->work.fsize = rlimit(RLIMIT_FSIZE); |
| else |
| req->work.fsize = RLIM_INFINITY; |
| } |
| |
| static void io_prep_async_link(struct io_kiocb *req) |
| { |
| struct io_kiocb *cur; |
| |
| io_prep_async_work(req); |
| if (req->flags & REQ_F_LINK_HEAD) |
| list_for_each_entry(cur, &req->link_list, link_list) |
| io_prep_async_work(cur); |
| } |
| |
| static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_kiocb *link = io_prep_linked_timeout(req); |
| |
| trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req, |
| &req->work, req->flags); |
| io_wq_enqueue(ctx->io_wq, &req->work); |
| return link; |
| } |
| |
| static void io_queue_async_work(struct io_kiocb *req) |
| { |
| struct io_kiocb *link; |
| |
| /* init ->work of the whole link before punting */ |
| io_prep_async_link(req); |
| link = __io_queue_async_work(req); |
| |
| if (link) |
| io_queue_linked_timeout(link); |
| } |
| |
| static void io_kill_timeout(struct io_kiocb *req) |
| { |
| int ret; |
| |
| ret = hrtimer_try_to_cancel(&req->io->timeout.timer); |
| if (ret != -1) { |
| atomic_set(&req->ctx->cq_timeouts, |
| atomic_read(&req->ctx->cq_timeouts) + 1); |
| list_del_init(&req->timeout.list); |
| req->flags |= REQ_F_COMP_LOCKED; |
| io_cqring_fill_event(req, 0); |
| io_put_req(req); |
| } |
| } |
| |
| static void io_kill_timeouts(struct io_ring_ctx *ctx) |
| { |
| struct io_kiocb *req, *tmp; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) |
| io_kill_timeout(req); |
| spin_unlock_irq(&ctx->completion_lock); |
| } |
| |
| static void __io_queue_deferred(struct io_ring_ctx *ctx) |
| { |
| do { |
| struct io_defer_entry *de = list_first_entry(&ctx->defer_list, |
| struct io_defer_entry, list); |
| struct io_kiocb *link; |
| |
| if (req_need_defer(de->req, de->seq)) |
| break; |
| list_del_init(&de->list); |
| /* punt-init is done before queueing for defer */ |
| link = __io_queue_async_work(de->req); |
| if (link) { |
| __io_queue_linked_timeout(link); |
| /* drop submission reference */ |
| link->flags |= REQ_F_COMP_LOCKED; |
| io_put_req(link); |
| } |
| kfree(de); |
| } while (!list_empty(&ctx->defer_list)); |
| } |
| |
| static void io_flush_timeouts(struct io_ring_ctx *ctx) |
| { |
| while (!list_empty(&ctx->timeout_list)) { |
| struct io_kiocb *req = list_first_entry(&ctx->timeout_list, |
| struct io_kiocb, timeout.list); |
| |
| if (io_is_timeout_noseq(req)) |
| break; |
| if (req->timeout.target_seq != ctx->cached_cq_tail |
| - atomic_read(&ctx->cq_timeouts)) |
| break; |
| |
| list_del_init(&req->timeout.list); |
| io_kill_timeout(req); |
| } |
| } |
| |
| static void io_commit_cqring(struct io_ring_ctx *ctx) |
| { |
| io_flush_timeouts(ctx); |
| __io_commit_cqring(ctx); |
| |
| if (unlikely(!list_empty(&ctx->defer_list))) |
| __io_queue_deferred(ctx); |
| } |
| |
| static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) |
| { |
| struct io_rings *rings = ctx->rings; |
| unsigned tail; |
| |
| tail = ctx->cached_cq_tail; |
| /* |
| * writes to the cq entry need to come after reading head; the |
| * control dependency is enough as we're using WRITE_ONCE to |
| * fill the cq entry |
| */ |
| if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries) |
| return NULL; |
| |
| ctx->cached_cq_tail++; |
| return &rings->cqes[tail & ctx->cq_mask]; |
| } |
| |
| static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx) |
| { |
| if (!ctx->cq_ev_fd) |
| return false; |
| if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED) |
| return false; |
| if (!ctx->eventfd_async) |
| return true; |
| return io_wq_current_is_worker(); |
| } |
| |
| static void io_cqring_ev_posted(struct io_ring_ctx *ctx) |
| { |
| if (waitqueue_active(&ctx->wait)) |
| wake_up(&ctx->wait); |
| if (waitqueue_active(&ctx->sqo_wait)) |
| wake_up(&ctx->sqo_wait); |
| if (io_should_trigger_evfd(ctx)) |
| eventfd_signal(ctx->cq_ev_fd, 1); |
| } |
| |
| static void io_cqring_mark_overflow(struct io_ring_ctx *ctx) |
| { |
| if (list_empty(&ctx->cq_overflow_list)) { |
| clear_bit(0, &ctx->sq_check_overflow); |
| clear_bit(0, &ctx->cq_check_overflow); |
| ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW; |
| } |
| } |
| |
| /* Returns true if there are no backlogged entries after the flush */ |
| static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force) |
| { |
| struct io_rings *rings = ctx->rings; |
| struct io_uring_cqe *cqe; |
| struct io_kiocb *req; |
| unsigned long flags; |
| LIST_HEAD(list); |
| |
| if (!force) { |
| if (list_empty_careful(&ctx->cq_overflow_list)) |
| return true; |
| if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) == |
| rings->cq_ring_entries)) |
| return false; |
| } |
| |
| spin_lock_irqsave(&ctx->completion_lock, flags); |
| |
| /* if force is set, the ring is going away. always drop after that */ |
| if (force) |
| ctx->cq_overflow_flushed = 1; |
| |
| cqe = NULL; |
| while (!list_empty(&ctx->cq_overflow_list)) { |
| cqe = io_get_cqring(ctx); |
| if (!cqe && !force) |
| break; |
| |
| req = list_first_entry(&ctx->cq_overflow_list, struct io_kiocb, |
| compl.list); |
| list_move(&req->compl.list, &list); |
| if (cqe) { |
| WRITE_ONCE(cqe->user_data, req->user_data); |
| WRITE_ONCE(cqe->res, req->result); |
| WRITE_ONCE(cqe->flags, req->compl.cflags); |
| } else { |
| WRITE_ONCE(ctx->rings->cq_overflow, |
| atomic_inc_return(&ctx->cached_cq_overflow)); |
| } |
| } |
| |
| io_commit_cqring(ctx); |
| io_cqring_mark_overflow(ctx); |
| |
| spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| io_cqring_ev_posted(ctx); |
| |
| while (!list_empty(&list)) { |
| req = list_first_entry(&list, struct io_kiocb, compl.list); |
| list_del(&req->compl.list); |
| io_put_req(req); |
| } |
| |
| return cqe != NULL; |
| } |
| |
| static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_uring_cqe *cqe; |
| |
| trace_io_uring_complete(ctx, req->user_data, res); |
| |
| /* |
| * If we can't get a cq entry, userspace overflowed the |
| * submission (by quite a lot). Increment the overflow count in |
| * the ring. |
| */ |
| cqe = io_get_cqring(ctx); |
| if (likely(cqe)) { |
| WRITE_ONCE(cqe->user_data, req->user_data); |
| WRITE_ONCE(cqe->res, res); |
| WRITE_ONCE(cqe->flags, cflags); |
| } else if (ctx->cq_overflow_flushed) { |
| WRITE_ONCE(ctx->rings->cq_overflow, |
| atomic_inc_return(&ctx->cached_cq_overflow)); |
| } else { |
| if (list_empty(&ctx->cq_overflow_list)) { |
| set_bit(0, &ctx->sq_check_overflow); |
| set_bit(0, &ctx->cq_check_overflow); |
| ctx->rings->sq_flags |= IORING_SQ_CQ_OVERFLOW; |
| } |
| io_clean_op(req); |
| req->result = res; |
| req->compl.cflags = cflags; |
| refcount_inc(&req->refs); |
| list_add_tail(&req->compl.list, &ctx->cq_overflow_list); |
| } |
| } |
| |
| static void io_cqring_fill_event(struct io_kiocb *req, long res) |
| { |
| __io_cqring_fill_event(req, res, 0); |
| } |
| |
| static void io_cqring_add_event(struct io_kiocb *req, long res, long cflags) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&ctx->completion_lock, flags); |
| __io_cqring_fill_event(req, res, cflags); |
| io_commit_cqring(ctx); |
| spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| |
| io_cqring_ev_posted(ctx); |
| } |
| |
| static void io_submit_flush_completions(struct io_comp_state *cs) |
| { |
| struct io_ring_ctx *ctx = cs->ctx; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| while (!list_empty(&cs->list)) { |
| struct io_kiocb *req; |
| |
| req = list_first_entry(&cs->list, struct io_kiocb, compl.list); |
| list_del(&req->compl.list); |
| __io_cqring_fill_event(req, req->result, req->compl.cflags); |
| if (!(req->flags & REQ_F_LINK_HEAD)) { |
| req->flags |= REQ_F_COMP_LOCKED; |
| io_put_req(req); |
| } else { |
| spin_unlock_irq(&ctx->completion_lock); |
| io_put_req(req); |
| spin_lock_irq(&ctx->completion_lock); |
| } |
| } |
| io_commit_cqring(ctx); |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| io_cqring_ev_posted(ctx); |
| cs->nr = 0; |
| } |
| |
| static void __io_req_complete(struct io_kiocb *req, long res, unsigned cflags, |
| struct io_comp_state *cs) |
| { |
| if (!cs) { |
| io_cqring_add_event(req, res, cflags); |
| io_put_req(req); |
| } else { |
| io_clean_op(req); |
| req->result = res; |
| req->compl.cflags = cflags; |
| list_add_tail(&req->compl.list, &cs->list); |
| if (++cs->nr >= 32) |
| io_submit_flush_completions(cs); |
| } |
| } |
| |
| static void io_req_complete(struct io_kiocb *req, long res) |
| { |
| __io_req_complete(req, res, 0, NULL); |
| } |
| |
| static inline bool io_is_fallback_req(struct io_kiocb *req) |
| { |
| return req == (struct io_kiocb *) |
| ((unsigned long) req->ctx->fallback_req & ~1UL); |
| } |
| |
| static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx) |
| { |
| struct io_kiocb *req; |
| |
| req = ctx->fallback_req; |
| if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req)) |
| return req; |
| |
| return NULL; |
| } |
| |
| static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx, |
| struct io_submit_state *state) |
| { |
| gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; |
| struct io_kiocb *req; |
| |
| if (!state->free_reqs) { |
| size_t sz; |
| int ret; |
| |
| sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs)); |
| ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs); |
| |
| /* |
| * Bulk alloc is all-or-nothing. If we fail to get a batch, |
| * retry single alloc to be on the safe side. |
| */ |
| if (unlikely(ret <= 0)) { |
| state->reqs[0] = kmem_cache_alloc(req_cachep, gfp); |
| if (!state->reqs[0]) |
| goto fallback; |
| ret = 1; |
| } |
| state->free_reqs = ret - 1; |
| req = state->reqs[ret - 1]; |
| } else { |
| state->free_reqs--; |
| req = state->reqs[state->free_reqs]; |
| } |
| |
| return req; |
| fallback: |
| return io_get_fallback_req(ctx); |
| } |
| |
| static inline void io_put_file(struct io_kiocb *req, struct file *file, |
| bool fixed) |
| { |
| if (fixed) |
| percpu_ref_put(req->fixed_file_refs); |
| else |
| fput(file); |
| } |
| |
| static bool io_dismantle_req(struct io_kiocb *req) |
| { |
| io_clean_op(req); |
| |
| if (req->io) |
| kfree(req->io); |
| if (req->file) |
| io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE)); |
| |
| return io_req_clean_work(req); |
| } |
| |
| static void __io_free_req_finish(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| __io_put_req_task(req); |
| if (likely(!io_is_fallback_req(req))) |
| kmem_cache_free(req_cachep, req); |
| else |
| clear_bit_unlock(0, (unsigned long *) &ctx->fallback_req); |
| percpu_ref_put(&ctx->refs); |
| } |
| |
| static void io_req_task_file_table_put(struct callback_head *cb) |
| { |
| struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
| struct fs_struct *fs = req->work.fs; |
| |
| spin_lock(&req->work.fs->lock); |
| if (--fs->users) |
| fs = NULL; |
| spin_unlock(&req->work.fs->lock); |
| if (fs) |
| free_fs_struct(fs); |
| req->work.fs = NULL; |
| __io_free_req_finish(req); |
| } |
| |
| static void __io_free_req(struct io_kiocb *req) |
| { |
| if (!io_dismantle_req(req)) { |
| __io_free_req_finish(req); |
| } else { |
| int ret; |
| |
| init_task_work(&req->task_work, io_req_task_file_table_put); |
| ret = task_work_add(req->task, &req->task_work, TWA_RESUME); |
| if (unlikely(ret)) { |
| struct task_struct *tsk; |
| |
| tsk = io_wq_get_task(req->ctx->io_wq); |
| task_work_add(tsk, &req->task_work, 0); |
| } |
| } |
| } |
| |
| static bool io_link_cancel_timeout(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| int ret; |
| |
| ret = hrtimer_try_to_cancel(&req->io->timeout.timer); |
| if (ret != -1) { |
| io_cqring_fill_event(req, -ECANCELED); |
| io_commit_cqring(ctx); |
| req->flags &= ~REQ_F_LINK_HEAD; |
| io_put_req(req); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static bool __io_kill_linked_timeout(struct io_kiocb *req) |
| { |
| struct io_kiocb *link; |
| bool wake_ev; |
| |
| if (list_empty(&req->link_list)) |
| return false; |
| link = list_first_entry(&req->link_list, struct io_kiocb, link_list); |
| if (link->opcode != IORING_OP_LINK_TIMEOUT) |
| return false; |
| |
| list_del_init(&link->link_list); |
| link->flags |= REQ_F_COMP_LOCKED; |
| wake_ev = io_link_cancel_timeout(link); |
| req->flags &= ~REQ_F_LINK_TIMEOUT; |
| return wake_ev; |
| } |
| |
| static void io_kill_linked_timeout(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| bool wake_ev; |
| |
| if (!(req->flags & REQ_F_COMP_LOCKED)) { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&ctx->completion_lock, flags); |
| wake_ev = __io_kill_linked_timeout(req); |
| spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| } else { |
| wake_ev = __io_kill_linked_timeout(req); |
| } |
| |
| if (wake_ev) |
| io_cqring_ev_posted(ctx); |
| } |
| |
| static struct io_kiocb *io_req_link_next(struct io_kiocb *req) |
| { |
| struct io_kiocb *nxt; |
| |
| /* |
| * The list should never be empty when we are called here. But could |
| * potentially happen if the chain is messed up, check to be on the |
| * safe side. |
| */ |
| if (unlikely(list_empty(&req->link_list))) |
| return NULL; |
| |
| nxt = list_first_entry(&req->link_list, struct io_kiocb, link_list); |
| list_del_init(&req->link_list); |
| if (!list_empty(&nxt->link_list)) |
| nxt->flags |= REQ_F_LINK_HEAD; |
| return nxt; |
| } |
| |
| /* |
| * Called if REQ_F_LINK_HEAD is set, and we fail the head request |
| */ |
| static void __io_fail_links(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| while (!list_empty(&req->link_list)) { |
| struct io_kiocb *link = list_first_entry(&req->link_list, |
| struct io_kiocb, link_list); |
| |
| list_del_init(&link->link_list); |
| trace_io_uring_fail_link(req, link); |
| |
| io_cqring_fill_event(link, -ECANCELED); |
| link->flags |= REQ_F_COMP_LOCKED; |
| __io_double_put_req(link); |
| req->flags &= ~REQ_F_LINK_TIMEOUT; |
| } |
| |
| io_commit_cqring(ctx); |
| io_cqring_ev_posted(ctx); |
| } |
| |
| static void io_fail_links(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| if (!(req->flags & REQ_F_COMP_LOCKED)) { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&ctx->completion_lock, flags); |
| __io_fail_links(req); |
| spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| } else { |
| __io_fail_links(req); |
| } |
| |
| io_cqring_ev_posted(ctx); |
| } |
| |
| static struct io_kiocb *__io_req_find_next(struct io_kiocb *req) |
| { |
| req->flags &= ~REQ_F_LINK_HEAD; |
| if (req->flags & REQ_F_LINK_TIMEOUT) |
| io_kill_linked_timeout(req); |
| |
| /* |
| * If LINK is set, we have dependent requests in this chain. If we |
| * didn't fail this request, queue the first one up, moving any other |
| * dependencies to the next request. In case of failure, fail the rest |
| * of the chain. |
| */ |
| if (likely(!(req->flags & REQ_F_FAIL_LINK))) |
| return io_req_link_next(req); |
| io_fail_links(req); |
| return NULL; |
| } |
| |
| static struct io_kiocb *io_req_find_next(struct io_kiocb *req) |
| { |
| if (likely(!(req->flags & REQ_F_LINK_HEAD))) |
| return NULL; |
| return __io_req_find_next(req); |
| } |
| |
| static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb, |
| bool twa_signal_ok) |
| { |
| struct task_struct *tsk = req->task; |
| struct io_ring_ctx *ctx = req->ctx; |
| int ret, notify; |
| |
| if (tsk->flags & PF_EXITING) |
| return -ESRCH; |
| |
| /* |
| * SQPOLL kernel thread doesn't need notification, just a wakeup. For |
| * all other cases, use TWA_SIGNAL unconditionally to ensure we're |
| * processing task_work. There's no reliable way to tell if TWA_RESUME |
| * will do the job. |
| */ |
| notify = 0; |
| if (!(ctx->flags & IORING_SETUP_SQPOLL) && twa_signal_ok) |
| notify = TWA_SIGNAL; |
| |
| ret = task_work_add(tsk, cb, notify); |
| if (!ret) |
| wake_up_process(tsk); |
| |
| return ret; |
| } |
| |
| static void __io_req_task_cancel(struct io_kiocb *req, int error) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| io_cqring_fill_event(req, error); |
| io_commit_cqring(ctx); |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| io_cqring_ev_posted(ctx); |
| req_set_fail_links(req); |
| io_double_put_req(req); |
| } |
| |
| static void io_req_task_cancel(struct callback_head *cb) |
| { |
| struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| __io_req_task_cancel(req, -ECANCELED); |
| percpu_ref_put(&ctx->refs); |
| } |
| |
| static void __io_req_task_submit(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| if (!__io_sq_thread_acquire_mm(ctx)) { |
| mutex_lock(&ctx->uring_lock); |
| __io_queue_sqe(req, NULL, NULL); |
| mutex_unlock(&ctx->uring_lock); |
| } else { |
| __io_req_task_cancel(req, -EFAULT); |
| } |
| } |
| |
| static void io_req_task_submit(struct callback_head *cb) |
| { |
| struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| __io_req_task_submit(req); |
| percpu_ref_put(&ctx->refs); |
| } |
| |
| static void io_req_task_queue(struct io_kiocb *req) |
| { |
| int ret; |
| |
| init_task_work(&req->task_work, io_req_task_submit); |
| percpu_ref_get(&req->ctx->refs); |
| |
| ret = io_req_task_work_add(req, &req->task_work, true); |
| if (unlikely(ret)) { |
| struct task_struct *tsk; |
| |
| init_task_work(&req->task_work, io_req_task_cancel); |
| tsk = io_wq_get_task(req->ctx->io_wq); |
| task_work_add(tsk, &req->task_work, 0); |
| wake_up_process(tsk); |
| } |
| } |
| |
| static void io_queue_next(struct io_kiocb *req) |
| { |
| struct io_kiocb *nxt = io_req_find_next(req); |
| |
| if (nxt) |
| io_req_task_queue(nxt); |
| } |
| |
| static void io_free_req(struct io_kiocb *req) |
| { |
| io_queue_next(req); |
| __io_free_req(req); |
| } |
| |
| struct req_batch { |
| void *reqs[IO_IOPOLL_BATCH]; |
| int to_free; |
| |
| struct task_struct *task; |
| int task_refs; |
| }; |
| |
| static inline void io_init_req_batch(struct req_batch *rb) |
| { |
| rb->to_free = 0; |
| rb->task_refs = 0; |
| rb->task = NULL; |
| } |
| |
| static void __io_req_free_batch_flush(struct io_ring_ctx *ctx, |
| struct req_batch *rb) |
| { |
| kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs); |
| percpu_ref_put_many(&ctx->refs, rb->to_free); |
| rb->to_free = 0; |
| } |
| |
| static void io_req_free_batch_finish(struct io_ring_ctx *ctx, |
| struct req_batch *rb) |
| { |
| if (rb->to_free) |
| __io_req_free_batch_flush(ctx, rb); |
| if (rb->task) { |
| put_task_struct_many(rb->task, rb->task_refs); |
| rb->task = NULL; |
| } |
| } |
| |
| static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req) |
| { |
| if (unlikely(io_is_fallback_req(req))) { |
| io_free_req(req); |
| return; |
| } |
| if (req->flags & REQ_F_LINK_HEAD) |
| io_queue_next(req); |
| |
| if (req->flags & REQ_F_TASK_PINNED) { |
| if (req->task != rb->task) { |
| if (rb->task) |
| put_task_struct_many(rb->task, rb->task_refs); |
| rb->task = req->task; |
| rb->task_refs = 0; |
| } |
| rb->task_refs++; |
| req->flags &= ~REQ_F_TASK_PINNED; |
| } |
| |
| WARN_ON_ONCE(io_dismantle_req(req)); |
| rb->reqs[rb->to_free++] = req; |
| if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs))) |
| __io_req_free_batch_flush(req->ctx, rb); |
| } |
| |
| /* |
| * Drop reference to request, return next in chain (if there is one) if this |
| * was the last reference to this request. |
| */ |
| static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req) |
| { |
| struct io_kiocb *nxt = NULL; |
| |
| if (refcount_dec_and_test(&req->refs)) { |
| nxt = io_req_find_next(req); |
| __io_free_req(req); |
| } |
| return nxt; |
| } |
| |
| static void io_put_req(struct io_kiocb *req) |
| { |
| if (refcount_dec_and_test(&req->refs)) |
| io_free_req(req); |
| } |
| |
| static struct io_wq_work *io_steal_work(struct io_kiocb *req) |
| { |
| struct io_kiocb *nxt; |
| |
| /* |
| * A ref is owned by io-wq in which context we're. So, if that's the |
| * last one, it's safe to steal next work. False negatives are Ok, |
| * it just will be re-punted async in io_put_work() |
| */ |
| if (refcount_read(&req->refs) != 1) |
| return NULL; |
| |
| nxt = io_req_find_next(req); |
| return nxt ? &nxt->work : NULL; |
| } |
| |
| /* |
| * Must only be used if we don't need to care about links, usually from |
| * within the completion handling itself. |
| */ |
| static void __io_double_put_req(struct io_kiocb *req) |
| { |
| /* drop both submit and complete references */ |
| if (refcount_sub_and_test(2, &req->refs)) |
| __io_free_req(req); |
| } |
| |
| static void io_double_put_req(struct io_kiocb *req) |
| { |
| /* drop both submit and complete references */ |
| if (refcount_sub_and_test(2, &req->refs)) |
| io_free_req(req); |
| } |
| |
| static unsigned io_cqring_events(struct io_ring_ctx *ctx, bool noflush) |
| { |
| struct io_rings *rings = ctx->rings; |
| |
| if (test_bit(0, &ctx->cq_check_overflow)) { |
| /* |
| * noflush == true is from the waitqueue handler, just ensure |
| * we wake up the task, and the next invocation will flush the |
| * entries. We cannot safely to it from here. |
| */ |
| if (noflush && !list_empty(&ctx->cq_overflow_list)) |
| return -1U; |
| |
| io_cqring_overflow_flush(ctx, false); |
| } |
| |
| /* See comment at the top of this file */ |
| smp_rmb(); |
| return ctx->cached_cq_tail - READ_ONCE(rings->cq.head); |
| } |
| |
| static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) |
| { |
| struct io_rings *rings = ctx->rings; |
| |
| /* make sure SQ entry isn't read before tail */ |
| return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; |
| } |
| |
| static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf) |
| { |
| unsigned int cflags; |
| |
| cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT; |
| cflags |= IORING_CQE_F_BUFFER; |
| req->flags &= ~REQ_F_BUFFER_SELECTED; |
| kfree(kbuf); |
| return cflags; |
| } |
| |
| static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req) |
| { |
| struct io_buffer *kbuf; |
| |
| kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; |
| return io_put_kbuf(req, kbuf); |
| } |
| |
| static inline bool io_run_task_work(void) |
| { |
| /* |
| * Not safe to run on exiting task, and the task_work handling will |
| * not add work to such a task. |
| */ |
| if (unlikely(current->flags & PF_EXITING)) |
| return false; |
| if (current->task_works) { |
| __set_current_state(TASK_RUNNING); |
| task_work_run(); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static void io_iopoll_queue(struct list_head *again) |
| { |
| struct io_kiocb *req; |
| |
| do { |
| req = list_first_entry(again, struct io_kiocb, inflight_entry); |
| list_del(&req->inflight_entry); |
| __io_complete_rw(req, -EAGAIN, 0, NULL); |
| } while (!list_empty(again)); |
| } |
| |
| /* |
| * Find and free completed poll iocbs |
| */ |
| static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, |
| struct list_head *done) |
| { |
| struct req_batch rb; |
| struct io_kiocb *req; |
| LIST_HEAD(again); |
| |
| /* order with ->result store in io_complete_rw_iopoll() */ |
| smp_rmb(); |
| |
| io_init_req_batch(&rb); |
| while (!list_empty(done)) { |
| int cflags = 0; |
| |
| req = list_first_entry(done, struct io_kiocb, inflight_entry); |
| if (READ_ONCE(req->result) == -EAGAIN) { |
| req->result = 0; |
| req->iopoll_completed = 0; |
| list_move_tail(&req->inflight_entry, &again); |
| continue; |
| } |
| list_del(&req->inflight_entry); |
| |
| if (req->flags & REQ_F_BUFFER_SELECTED) |
| cflags = io_put_rw_kbuf(req); |
| |
| __io_cqring_fill_event(req, req->result, cflags); |
| (*nr_events)++; |
| |
| if (refcount_dec_and_test(&req->refs)) |
| io_req_free_batch(&rb, req); |
| } |
| |
| io_commit_cqring(ctx); |
| if (ctx->flags & IORING_SETUP_SQPOLL) |
| io_cqring_ev_posted(ctx); |
| io_req_free_batch_finish(ctx, &rb); |
| |
| if (!list_empty(&again)) |
| io_iopoll_queue(&again); |
| } |
| |
| static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, |
| long min) |
| { |
| struct io_kiocb *req, *tmp; |
| LIST_HEAD(done); |
| bool spin; |
| int ret; |
| |
| /* |
| * Only spin for completions if we don't have multiple devices hanging |
| * off our complete list, and we're under the requested amount. |
| */ |
| spin = !ctx->poll_multi_file && *nr_events < min; |
| |
| ret = 0; |
| list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) { |
| struct kiocb *kiocb = &req->rw.kiocb; |
| |
| /* |
| * Move completed and retryable entries to our local lists. |
| * If we find a request that requires polling, break out |
| * and complete those lists first, if we have entries there. |
| */ |
| if (READ_ONCE(req->iopoll_completed)) { |
| list_move_tail(&req->inflight_entry, &done); |
| continue; |
| } |
| if (!list_empty(&done)) |
| break; |
| |
| ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin); |
| if (ret < 0) |
| break; |
| |
| /* iopoll may have completed current req */ |
| if (READ_ONCE(req->iopoll_completed)) |
| list_move_tail(&req->inflight_entry, &done); |
| |
| if (ret && spin) |
| spin = false; |
| ret = 0; |
| } |
| |
| if (!list_empty(&done)) |
| io_iopoll_complete(ctx, nr_events, &done); |
| |
| return ret; |
| } |
| |
| /* |
| * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a |
| * non-spinning poll check - we'll still enter the driver poll loop, but only |
| * as a non-spinning completion check. |
| */ |
| static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events, |
| long min) |
| { |
| while (!list_empty(&ctx->iopoll_list) && !need_resched()) { |
| int ret; |
| |
| ret = io_do_iopoll(ctx, nr_events, min); |
| if (ret < 0) |
| return ret; |
| if (*nr_events >= min) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* |
| * We can't just wait for polled events to come to us, we have to actively |
| * find and complete them. |
| */ |
| static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx) |
| { |
| if (!(ctx->flags & IORING_SETUP_IOPOLL)) |
| return; |
| |
| mutex_lock(&ctx->uring_lock); |
| while (!list_empty(&ctx->iopoll_list)) { |
| unsigned int nr_events = 0; |
| |
| io_do_iopoll(ctx, &nr_events, 0); |
| |
| /* let it sleep and repeat later if can't complete a request */ |
| if (nr_events == 0) |
| break; |
| /* |
| * Ensure we allow local-to-the-cpu processing to take place, |
| * in this case we need to ensure that we reap all events. |
| * Also let task_work, etc. to progress by releasing the mutex |
| */ |
| if (need_resched()) { |
| mutex_unlock(&ctx->uring_lock); |
| cond_resched(); |
| mutex_lock(&ctx->uring_lock); |
| } |
| } |
| mutex_unlock(&ctx->uring_lock); |
| } |
| |
| static int io_iopoll_check(struct io_ring_ctx *ctx, long min) |
| { |
| unsigned int nr_events = 0; |
| int iters = 0, ret = 0; |
| |
| /* |
| * We disallow the app entering submit/complete with polling, but we |
| * still need to lock the ring to prevent racing with polled issue |
| * that got punted to a workqueue. |
| */ |
| mutex_lock(&ctx->uring_lock); |
| do { |
| /* |
| * Don't enter poll loop if we already have events pending. |
| * If we do, we can potentially be spinning for commands that |
| * already triggered a CQE (eg in error). |
| */ |
| if (io_cqring_events(ctx, false)) |
| break; |
| |
| /* |
| * If a submit got punted to a workqueue, we can have the |
| * application entering polling for a command before it gets |
| * issued. That app will hold the uring_lock for the duration |
| * of the poll right here, so we need to take a breather every |
| * now and then to ensure that the issue has a chance to add |
| * the poll to the issued list. Otherwise we can spin here |
| * forever, while the workqueue is stuck trying to acquire the |
| * very same mutex. |
| */ |
| if (!(++iters & 7)) { |
| mutex_unlock(&ctx->uring_lock); |
| io_run_task_work(); |
| mutex_lock(&ctx->uring_lock); |
| } |
| |
| ret = io_iopoll_getevents(ctx, &nr_events, min); |
| if (ret <= 0) |
| break; |
| ret = 0; |
| } while (min && !nr_events && !need_resched()); |
| |
| mutex_unlock(&ctx->uring_lock); |
| return ret; |
| } |
| |
| static void kiocb_end_write(struct io_kiocb *req) |
| { |
| /* |
| * Tell lockdep we inherited freeze protection from submission |
| * thread. |
| */ |
| if (req->flags & REQ_F_ISREG) { |
| struct inode *inode = file_inode(req->file); |
| |
| __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); |
| } |
| file_end_write(req->file); |
| } |
| |
| static void io_complete_rw_common(struct kiocb *kiocb, long res, |
| struct io_comp_state *cs) |
| { |
| struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
| int cflags = 0; |
| |
| if (kiocb->ki_flags & IOCB_WRITE) |
| kiocb_end_write(req); |
| |
| if (res != req->result) |
| req_set_fail_links(req); |
| if (req->flags & REQ_F_BUFFER_SELECTED) |
| cflags = io_put_rw_kbuf(req); |
| __io_req_complete(req, res, cflags, cs); |
| } |
| |
| #ifdef CONFIG_BLOCK |
| static bool io_resubmit_prep(struct io_kiocb *req, int error) |
| { |
| struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
| ssize_t ret = -ECANCELED; |
| struct iov_iter iter; |
| int rw; |
| |
| if (error) { |
| ret = error; |
| goto end_req; |
| } |
| |
| switch (req->opcode) { |
| case IORING_OP_READV: |
| case IORING_OP_READ_FIXED: |
| case IORING_OP_READ: |
| rw = READ; |
| break; |
| case IORING_OP_WRITEV: |
| case IORING_OP_WRITE_FIXED: |
| case IORING_OP_WRITE: |
| rw = WRITE; |
| break; |
| default: |
| printk_once(KERN_WARNING "io_uring: bad opcode in resubmit %d\n", |
| req->opcode); |
| goto end_req; |
| } |
| |
| if (!req->io) { |
| ret = io_import_iovec(rw, req, &iovec, &iter, false); |
| if (ret < 0) |
| goto end_req; |
| ret = io_setup_async_rw(req, iovec, inline_vecs, &iter, false); |
| if (!ret) |
| return true; |
| kfree(iovec); |
| } else { |
| return true; |
| } |
| end_req: |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return false; |
| } |
| #endif |
| |
| static bool io_rw_reissue(struct io_kiocb *req, long res) |
| { |
| #ifdef CONFIG_BLOCK |
| umode_t mode = file_inode(req->file)->i_mode; |
| int ret; |
| |
| if (!S_ISBLK(mode) && !S_ISREG(mode)) |
| return false; |
| if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker()) |
| return false; |
| |
| ret = io_sq_thread_acquire_mm(req->ctx, req); |
| |
| if (io_resubmit_prep(req, ret)) { |
| refcount_inc(&req->refs); |
| io_queue_async_work(req); |
| return true; |
| } |
| |
| #endif |
| return false; |
| } |
| |
| static void __io_complete_rw(struct io_kiocb *req, long res, long res2, |
| struct io_comp_state *cs) |
| { |
| if (!io_rw_reissue(req, res)) |
| io_complete_rw_common(&req->rw.kiocb, res, cs); |
| } |
| |
| static void io_complete_rw(struct kiocb *kiocb, long res, long res2) |
| { |
| struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
| |
| __io_complete_rw(req, res, res2, NULL); |
| } |
| |
| static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) |
| { |
| struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
| |
| if (kiocb->ki_flags & IOCB_WRITE) |
| kiocb_end_write(req); |
| |
| if (res != -EAGAIN && res != req->result) |
| req_set_fail_links(req); |
| |
| WRITE_ONCE(req->result, res); |
| /* order with io_poll_complete() checking ->result */ |
| smp_wmb(); |
| WRITE_ONCE(req->iopoll_completed, 1); |
| } |
| |
| /* |
| * After the iocb has been issued, it's safe to be found on the poll list. |
| * Adding the kiocb to the list AFTER submission ensures that we don't |
| * find it from a io_iopoll_getevents() thread before the issuer is done |
| * accessing the kiocb cookie. |
| */ |
| static void io_iopoll_req_issued(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| /* |
| * Track whether we have multiple files in our lists. This will impact |
| * how we do polling eventually, not spinning if we're on potentially |
| * different devices. |
| */ |
| if (list_empty(&ctx->iopoll_list)) { |
| ctx->poll_multi_file = false; |
| } else if (!ctx->poll_multi_file) { |
| struct io_kiocb *list_req; |
| |
| list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb, |
| inflight_entry); |
| if (list_req->file != req->file) |
| ctx->poll_multi_file = true; |
| } |
| |
| /* |
| * For fast devices, IO may have already completed. If it has, add |
| * it to the front so we find it first. |
| */ |
| if (READ_ONCE(req->iopoll_completed)) |
| list_add(&req->inflight_entry, &ctx->iopoll_list); |
| else |
| list_add_tail(&req->inflight_entry, &ctx->iopoll_list); |
| |
| if ((ctx->flags & IORING_SETUP_SQPOLL) && |
| wq_has_sleeper(&ctx->sqo_wait)) |
| wake_up(&ctx->sqo_wait); |
| } |
| |
| static void __io_state_file_put(struct io_submit_state *state) |
| { |
| if (state->has_refs) |
| fput_many(state->file, state->has_refs); |
| state->file = NULL; |
| } |
| |
| static inline void io_state_file_put(struct io_submit_state *state) |
| { |
| if (state->file) |
| __io_state_file_put(state); |
| } |
| |
| /* |
| * Get as many references to a file as we have IOs left in this submission, |
| * assuming most submissions are for one file, or at least that each file |
| * has more than one submission. |
| */ |
| static struct file *__io_file_get(struct io_submit_state *state, int fd) |
| { |
| if (!state) |
| return fget(fd); |
| |
| if (state->file) { |
| if (state->fd == fd) { |
| state->has_refs--; |
| state->ios_left--; |
| return state->file; |
| } |
| __io_state_file_put(state); |
| } |
| state->file = fget_many(fd, state->ios_left); |
| if (!state->file) |
| return NULL; |
| |
| state->fd = fd; |
| state->ios_left--; |
| state->has_refs = state->ios_left; |
| return state->file; |
| } |
| |
| static bool io_bdev_nowait(struct block_device *bdev) |
| { |
| #ifdef CONFIG_BLOCK |
| return !bdev || queue_is_mq(bdev_get_queue(bdev)); |
| #else |
| return true; |
| #endif |
| } |
| |
| /* |
| * If we tracked the file through the SCM inflight mechanism, we could support |
| * any file. For now, just ensure that anything potentially problematic is done |
| * inline. |
| */ |
| static bool io_file_supports_async(struct file *file, int rw) |
| { |
| umode_t mode = file_inode(file)->i_mode; |
| |
| if (S_ISBLK(mode)) { |
| if (io_bdev_nowait(file->f_inode->i_bdev)) |
| return true; |
| return false; |
| } |
| if (S_ISCHR(mode) || S_ISSOCK(mode)) |
| return true; |
| if (S_ISREG(mode)) { |
| if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) && |
| file->f_op != &io_uring_fops) |
| return true; |
| return false; |
| } |
| |
| /* any ->read/write should understand O_NONBLOCK */ |
| if (file->f_flags & O_NONBLOCK) |
| return true; |
| |
| if (!(file->f_mode & FMODE_NOWAIT)) |
| return false; |
| |
| if (rw == READ) |
| return file->f_op->read_iter != NULL; |
| |
| return file->f_op->write_iter != NULL; |
| } |
| |
| static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
| bool force_nonblock) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| struct kiocb *kiocb = &req->rw.kiocb; |
| unsigned ioprio; |
| int ret; |
| |
| if (S_ISREG(file_inode(req->file)->i_mode)) |
| req->flags |= REQ_F_ISREG; |
| |
| kiocb->ki_pos = READ_ONCE(sqe->off); |
| if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) { |
| req->flags |= REQ_F_CUR_POS; |
| kiocb->ki_pos = req->file->f_pos; |
| } |
| kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); |
| kiocb->ki_flags = iocb_flags(kiocb->ki_filp); |
| ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); |
| if (unlikely(ret)) |
| return ret; |
| |
| ioprio = READ_ONCE(sqe->ioprio); |
| if (ioprio) { |
| ret = ioprio_check_cap(ioprio); |
| if (ret) |
| return ret; |
| |
| kiocb->ki_ioprio = ioprio; |
| } else |
| kiocb->ki_ioprio = get_current_ioprio(); |
| |
| /* don't allow async punt if RWF_NOWAIT was requested */ |
| if (kiocb->ki_flags & IOCB_NOWAIT) |
| req->flags |= REQ_F_NOWAIT; |
| |
| if (kiocb->ki_flags & IOCB_DIRECT) |
| io_get_req_task(req); |
| |
| if (force_nonblock) |
| kiocb->ki_flags |= IOCB_NOWAIT; |
| |
| if (ctx->flags & IORING_SETUP_IOPOLL) { |
| if (!(kiocb->ki_flags & IOCB_DIRECT) || |
| !kiocb->ki_filp->f_op->iopoll) |
| return -EOPNOTSUPP; |
| |
| kiocb->ki_flags |= IOCB_HIPRI; |
| kiocb->ki_complete = io_complete_rw_iopoll; |
| req->iopoll_completed = 0; |
| io_get_req_task(req); |
| } else { |
| if (kiocb->ki_flags & IOCB_HIPRI) |
| return -EINVAL; |
| kiocb->ki_complete = io_complete_rw; |
| } |
| |
| req->rw.addr = READ_ONCE(sqe->addr); |
| req->rw.len = READ_ONCE(sqe->len); |
| req->buf_index = READ_ONCE(sqe->buf_index); |
| return 0; |
| } |
| |
| static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) |
| { |
| switch (ret) { |
| case -EIOCBQUEUED: |
| break; |
| case -ERESTARTSYS: |
| case -ERESTARTNOINTR: |
| case -ERESTARTNOHAND: |
| case -ERESTART_RESTARTBLOCK: |
| /* |
| * We can't just restart the syscall, since previously |
| * submitted sqes may already be in progress. Just fail this |
| * IO with EINTR. |
| */ |
| ret = -EINTR; |
| fallthrough; |
| default: |
| kiocb->ki_complete(kiocb, ret, 0); |
| } |
| } |
| |
| static void kiocb_done(struct kiocb *kiocb, ssize_t ret, |
| struct io_comp_state *cs) |
| { |
| struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
| |
| /* add previously done IO, if any */ |
| if (req->io && req->io->rw.bytes_done > 0) { |
| if (ret < 0) |
| ret = req->io->rw.bytes_done; |
| else |
| ret += req->io->rw.bytes_done; |
| } |
| |
| if (req->flags & REQ_F_CUR_POS) |
| req->file->f_pos = kiocb->ki_pos; |
| if (ret >= 0 && kiocb->ki_complete == io_complete_rw) |
| __io_complete_rw(req, ret, 0, cs); |
| else |
| io_rw_done(kiocb, ret); |
| } |
| |
| static ssize_t io_import_fixed(struct io_kiocb *req, int rw, |
| struct iov_iter *iter) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| size_t len = req->rw.len; |
| struct io_mapped_ubuf *imu; |
| u16 index, buf_index; |
| size_t offset; |
| u64 buf_addr; |
| |
| /* attempt to use fixed buffers without having provided iovecs */ |
| if (unlikely(!ctx->user_bufs)) |
| return -EFAULT; |
| |
| buf_index = req->buf_index; |
| if (unlikely(buf_index >= ctx->nr_user_bufs)) |
| return -EFAULT; |
| |
| index = array_index_nospec(buf_index, ctx->nr_user_bufs); |
| imu = &ctx->user_bufs[index]; |
| buf_addr = req->rw.addr; |
| |
| /* overflow */ |
| if (buf_addr + len < buf_addr) |
| return -EFAULT; |
| /* not inside the mapped region */ |
| if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len) |
| return -EFAULT; |
| |
| /* |
| * May not be a start of buffer, set size appropriately |
| * and advance us to the beginning. |
| */ |
| offset = buf_addr - imu->ubuf; |
| iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len); |
| |
| if (offset) { |
| /* |
| * Don't use iov_iter_advance() here, as it's really slow for |
| * using the latter parts of a big fixed buffer - it iterates |
| * over each segment manually. We can cheat a bit here, because |
| * we know that: |
| * |
| * 1) it's a BVEC iter, we set it up |
| * 2) all bvecs are PAGE_SIZE in size, except potentially the |
| * first and last bvec |
| * |
| * So just find our index, and adjust the iterator afterwards. |
| * If the offset is within the first bvec (or the whole first |
| * bvec, just use iov_iter_advance(). This makes it easier |
| * since we can just skip the first segment, which may not |
| * be PAGE_SIZE aligned. |
| */ |
| const struct bio_vec *bvec = imu->bvec; |
| |
| if (offset <= bvec->bv_len) { |
| iov_iter_advance(iter, offset); |
| } else { |
| unsigned long seg_skip; |
| |
| /* skip first vec */ |
| offset -= bvec->bv_len; |
| seg_skip = 1 + (offset >> PAGE_SHIFT); |
| |
| iter->bvec = bvec + seg_skip; |
| iter->nr_segs -= seg_skip; |
| iter->count -= bvec->bv_len + offset; |
| iter->iov_offset = offset & ~PAGE_MASK; |
| } |
| } |
| |
| return len; |
| } |
| |
| static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock) |
| { |
| if (needs_lock) |
| mutex_unlock(&ctx->uring_lock); |
| } |
| |
| static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock) |
| { |
| /* |
| * "Normal" inline submissions always hold the uring_lock, since we |
| * grab it from the system call. Same is true for the SQPOLL offload. |
| * The only exception is when we've detached the request and issue it |
| * from an async worker thread, grab the lock for that case. |
| */ |
| if (needs_lock) |
| mutex_lock(&ctx->uring_lock); |
| } |
| |
| static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len, |
| int bgid, struct io_buffer *kbuf, |
| bool needs_lock) |
| { |
| struct io_buffer *head; |
| |
| if (req->flags & REQ_F_BUFFER_SELECTED) |
| return kbuf; |
| |
| io_ring_submit_lock(req->ctx, needs_lock); |
| |
| lockdep_assert_held(&req->ctx->uring_lock); |
| |
| head = idr_find(&req->ctx->io_buffer_idr, bgid); |
| if (head) { |
| if (!list_empty(&head->list)) { |
| kbuf = list_last_entry(&head->list, struct io_buffer, |
| list); |
| list_del(&kbuf->list); |
| } else { |
| kbuf = head; |
| idr_remove(&req->ctx->io_buffer_idr, bgid); |
| } |
| if (*len > kbuf->len) |
| *len = kbuf->len; |
| } else { |
| kbuf = ERR_PTR(-ENOBUFS); |
| } |
| |
| io_ring_submit_unlock(req->ctx, needs_lock); |
| |
| return kbuf; |
| } |
| |
| static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len, |
| bool needs_lock) |
| { |
| struct io_buffer *kbuf; |
| u16 bgid; |
| |
| kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; |
| bgid = req->buf_index; |
| kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock); |
| if (IS_ERR(kbuf)) |
| return kbuf; |
| req->rw.addr = (u64) (unsigned long) kbuf; |
| req->flags |= REQ_F_BUFFER_SELECTED; |
| return u64_to_user_ptr(kbuf->addr); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov, |
| bool needs_lock) |
| { |
| struct compat_iovec __user *uiov; |
| compat_ssize_t clen; |
| void __user *buf; |
| ssize_t len; |
| |
| uiov = u64_to_user_ptr(req->rw.addr); |
| if (!access_ok(uiov, sizeof(*uiov))) |
| return -EFAULT; |
| if (__get_user(clen, &uiov->iov_len)) |
| return -EFAULT; |
| if (clen < 0) |
| return -EINVAL; |
| |
| len = clen; |
| buf = io_rw_buffer_select(req, &len, needs_lock); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| iov[0].iov_base = buf; |
| iov[0].iov_len = (compat_size_t) len; |
| return 0; |
| } |
| #endif |
| |
| static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov, |
| bool needs_lock) |
| { |
| struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr); |
| void __user *buf; |
| ssize_t len; |
| |
| if (copy_from_user(iov, uiov, sizeof(*uiov))) |
| return -EFAULT; |
| |
| len = iov[0].iov_len; |
| if (len < 0) |
| return -EINVAL; |
| buf = io_rw_buffer_select(req, &len, needs_lock); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| iov[0].iov_base = buf; |
| iov[0].iov_len = len; |
| return 0; |
| } |
| |
| static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov, |
| bool needs_lock) |
| { |
| if (req->flags & REQ_F_BUFFER_SELECTED) { |
| struct io_buffer *kbuf; |
| |
| kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; |
| iov[0].iov_base = u64_to_user_ptr(kbuf->addr); |
| iov[0].iov_len = kbuf->len; |
| return 0; |
| } |
| if (!req->rw.len) |
| return 0; |
| else if (req->rw.len > 1) |
| return -EINVAL; |
| |
| #ifdef CONFIG_COMPAT |
| if (req->ctx->compat) |
| return io_compat_import(req, iov, needs_lock); |
| #endif |
| |
| return __io_iov_buffer_select(req, iov, needs_lock); |
| } |
| |
| static ssize_t __io_import_iovec(int rw, struct io_kiocb *req, |
| struct iovec **iovec, struct iov_iter *iter, |
| bool needs_lock) |
| { |
| void __user *buf = u64_to_user_ptr(req->rw.addr); |
| size_t sqe_len = req->rw.len; |
| ssize_t ret; |
| u8 opcode; |
| |
| opcode = req->opcode; |
| if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { |
| *iovec = NULL; |
| return io_import_fixed(req, rw, iter); |
| } |
| |
| /* buffer index only valid with fixed read/write, or buffer select */ |
| if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT)) |
| return -EINVAL; |
| |
| if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) { |
| if (req->flags & REQ_F_BUFFER_SELECT) { |
| buf = io_rw_buffer_select(req, &sqe_len, needs_lock); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| req->rw.len = sqe_len; |
| } |
| |
| ret = import_single_range(rw, buf, sqe_len, *iovec, iter); |
| *iovec = NULL; |
| return ret < 0 ? ret : sqe_len; |
| } |
| |
| if (req->flags & REQ_F_BUFFER_SELECT) { |
| ret = io_iov_buffer_select(req, *iovec, needs_lock); |
| if (!ret) { |
| ret = (*iovec)->iov_len; |
| iov_iter_init(iter, rw, *iovec, 1, ret); |
| } |
| *iovec = NULL; |
| return ret; |
| } |
| |
| #ifdef CONFIG_COMPAT |
| if (req->ctx->compat) |
| return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV, |
| iovec, iter); |
| #endif |
| |
| return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter); |
| } |
| |
| static ssize_t io_import_iovec(int rw, struct io_kiocb *req, |
| struct iovec **iovec, struct iov_iter *iter, |
| bool needs_lock) |
| { |
| if (!req->io) |
| return __io_import_iovec(rw, req, iovec, iter, needs_lock); |
| *iovec = NULL; |
| return iov_iter_count(&req->io->rw.iter); |
| } |
| |
| static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) |
| { |
| return kiocb->ki_filp->f_mode & FMODE_STREAM ? NULL : &kiocb->ki_pos; |
| } |
| |
| /* |
| * For files that don't have ->read_iter() and ->write_iter(), handle them |
| * by looping over ->read() or ->write() manually. |
| */ |
| static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb, |
| struct iov_iter *iter) |
| { |
| ssize_t ret = 0; |
| |
| /* |
| * Don't support polled IO through this interface, and we can't |
| * support non-blocking either. For the latter, this just causes |
| * the kiocb to be handled from an async context. |
| */ |
| if (kiocb->ki_flags & IOCB_HIPRI) |
| return -EOPNOTSUPP; |
| if (kiocb->ki_flags & IOCB_NOWAIT) |
| return -EAGAIN; |
| |
| while (iov_iter_count(iter)) { |
| struct iovec iovec; |
| ssize_t nr; |
| |
| if (!iov_iter_is_bvec(iter)) { |
| iovec = iov_iter_iovec(iter); |
| } else { |
| /* fixed buffers import bvec */ |
| iovec.iov_base = kmap(iter->bvec->bv_page) |
| + iter->iov_offset; |
| iovec.iov_len = min(iter->count, |
| iter->bvec->bv_len - iter->iov_offset); |
| } |
| |
| if (rw == READ) { |
| nr = file->f_op->read(file, iovec.iov_base, |
| iovec.iov_len, io_kiocb_ppos(kiocb)); |
| } else { |
| nr = file->f_op->write(file, iovec.iov_base, |
| iovec.iov_len, io_kiocb_ppos(kiocb)); |
| } |
| |
| if (iov_iter_is_bvec(iter)) |
| kunmap(iter->bvec->bv_page); |
| |
| if (nr < 0) { |
| if (!ret) |
| ret = nr; |
| break; |
| } |
| ret += nr; |
| if (nr != iovec.iov_len) |
| break; |
| iov_iter_advance(iter, nr); |
| } |
| |
| return ret; |
| } |
| |
| static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec, |
| const struct iovec *fast_iov, struct iov_iter *iter) |
| { |
| struct io_async_rw *rw = &req->io->rw; |
| |
| memcpy(&rw->iter, iter, sizeof(*iter)); |
| rw->free_iovec = NULL; |
| rw->bytes_done = 0; |
| /* can only be fixed buffers, no need to do anything */ |
| if (iter->type == ITER_BVEC) |
| return; |
| if (!iovec) { |
| unsigned iov_off = 0; |
| |
| rw->iter.iov = rw->fast_iov; |
| if (iter->iov != fast_iov) { |
| iov_off = iter->iov - fast_iov; |
| rw->iter.iov += iov_off; |
| } |
| if (rw->fast_iov != fast_iov) |
| memcpy(rw->fast_iov + iov_off, fast_iov + iov_off, |
| sizeof(struct iovec) * iter->nr_segs); |
| } else { |
| rw->free_iovec = iovec; |
| req->flags |= REQ_F_NEED_CLEANUP; |
| } |
| } |
| |
| static inline int __io_alloc_async_ctx(struct io_kiocb *req) |
| { |
| req->io = kmalloc(sizeof(*req->io), GFP_KERNEL); |
| return req->io == NULL; |
| } |
| |
| static int io_alloc_async_ctx(struct io_kiocb *req) |
| { |
| if (!io_op_defs[req->opcode].async_ctx) |
| return 0; |
| |
| return __io_alloc_async_ctx(req); |
| } |
| |
| static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, |
| const struct iovec *fast_iov, |
| struct iov_iter *iter, bool force) |
| { |
| if (!force && !io_op_defs[req->opcode].async_ctx) |
| return 0; |
| if (!req->io) { |
| if (__io_alloc_async_ctx(req)) |
| return -ENOMEM; |
| |
| io_req_map_rw(req, iovec, fast_iov, iter); |
| } |
| return 0; |
| } |
| |
| static inline int io_rw_prep_async(struct io_kiocb *req, int rw, |
| bool force_nonblock) |
| { |
| struct io_async_rw *iorw = &req->io->rw; |
| struct iovec *iov; |
| ssize_t ret; |
| |
| iorw->iter.iov = iov = iorw->fast_iov; |
| ret = __io_import_iovec(rw, req, &iov, &iorw->iter, !force_nonblock); |
| if (unlikely(ret < 0)) |
| return ret; |
| |
| iorw->iter.iov = iov; |
| io_req_map_rw(req, iorw->iter.iov, iorw->fast_iov, &iorw->iter); |
| return 0; |
| } |
| |
| static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
| bool force_nonblock) |
| { |
| ssize_t ret; |
| |
| ret = io_prep_rw(req, sqe, force_nonblock); |
| if (ret) |
| return ret; |
| |
| if (unlikely(!(req->file->f_mode & FMODE_READ))) |
| return -EBADF; |
| |
| /* either don't need iovec imported or already have it */ |
| if (!req->io || req->flags & REQ_F_NEED_CLEANUP) |
| return 0; |
| return io_rw_prep_async(req, READ, force_nonblock); |
| } |
| |
| /* |
| * This is our waitqueue callback handler, registered through lock_page_async() |
| * when we initially tried to do the IO with the iocb armed our waitqueue. |
| * This gets called when the page is unlocked, and we generally expect that to |
| * happen when the page IO is completed and the page is now uptodate. This will |
| * queue a task_work based retry of the operation, attempting to copy the data |
| * again. If the latter fails because the page was NOT uptodate, then we will |
| * do a thread based blocking retry of the operation. That's the unexpected |
| * slow path. |
| */ |
| static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, |
| int sync, void *arg) |
| { |
| struct wait_page_queue *wpq; |
| struct io_kiocb *req = wait->private; |
| struct wait_page_key *key = arg; |
| int ret; |
| |
| wpq = container_of(wait, struct wait_page_queue, wait); |
| |
| if (!wake_page_match(wpq, key)) |
| return 0; |
| |
| req->rw.kiocb.ki_flags &= ~IOCB_WAITQ; |
| list_del_init(&wait->entry); |
| |
| init_task_work(&req->task_work, io_req_task_submit); |
| percpu_ref_get(&req->ctx->refs); |
| |
| /* submit ref gets dropped, acquire a new one */ |
| refcount_inc(&req->refs); |
| ret = io_req_task_work_add(req, &req->task_work, true); |
| if (unlikely(ret)) { |
| struct task_struct *tsk; |
| |
| /* queue just for cancelation */ |
| init_task_work(&req->task_work, io_req_task_cancel); |
| tsk = io_wq_get_task(req->ctx->io_wq); |
| task_work_add(tsk, &req->task_work, 0); |
| wake_up_process(tsk); |
| } |
| return 1; |
| } |
| |
| /* |
| * This controls whether a given IO request should be armed for async page |
| * based retry. If we return false here, the request is handed to the async |
| * worker threads for retry. If we're doing buffered reads on a regular file, |
| * we prepare a private wait_page_queue entry and retry the operation. This |
| * will either succeed because the page is now uptodate and unlocked, or it |
| * will register a callback when the page is unlocked at IO completion. Through |
| * that callback, io_uring uses task_work to setup a retry of the operation. |
| * That retry will attempt the buffered read again. The retry will generally |
| * succeed, or in rare cases where it fails, we then fall back to using the |
| * async worker threads for a blocking retry. |
| */ |
| static bool io_rw_should_retry(struct io_kiocb *req) |
| { |
| struct wait_page_queue *wait = &req->io->rw.wpq; |
| struct kiocb *kiocb = &req->rw.kiocb; |
| |
| /* never retry for NOWAIT, we just complete with -EAGAIN */ |
| if (req->flags & REQ_F_NOWAIT) |
| return false; |
| |
| /* Only for buffered IO */ |
| if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI)) |
| return false; |
| |
| /* |
| * just use poll if we can, and don't attempt if the fs doesn't |
| * support callback based unlocks |
| */ |
| if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC)) |
| return false; |
| |
| wait->wait.func = io_async_buf_func; |
| wait->wait.private = req; |
| wait->wait.flags = 0; |
| INIT_LIST_HEAD(&wait->wait.entry); |
| kiocb->ki_flags |= IOCB_WAITQ; |
| kiocb->ki_flags &= ~IOCB_NOWAIT; |
| kiocb->ki_waitq = wait; |
| |
| io_get_req_task(req); |
| return true; |
| } |
| |
| static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter) |
| { |
| if (req->file->f_op->read_iter) |
| return call_read_iter(req->file, &req->rw.kiocb, iter); |
| else if (req->file->f_op->read) |
| return loop_rw_iter(READ, req->file, &req->rw.kiocb, iter); |
| else |
| return -EINVAL; |
| } |
| |
| static int io_read(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
| struct kiocb *kiocb = &req->rw.kiocb; |
| struct iov_iter __iter, *iter = &__iter; |
| ssize_t io_size, ret, ret2; |
| size_t iov_count; |
| bool no_async; |
| |
| if (req->io) |
| iter = &req->io->rw.iter; |
| |
| ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock); |
| if (ret < 0) |
| return ret; |
| iov_count = iov_iter_count(iter); |
| io_size = ret; |
| req->result = io_size; |
| ret = 0; |
| |
| /* Ensure we clear previously set non-block flag */ |
| if (!force_nonblock) |
| kiocb->ki_flags &= ~IOCB_NOWAIT; |
| |
| /* If the file doesn't support async, just async punt */ |
| no_async = force_nonblock && !io_file_supports_async(req->file, READ); |
| if (no_async) |
| goto copy_iov; |
| |
| ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), iov_count); |
| if (unlikely(ret)) |
| goto out_free; |
| |
| ret = io_iter_do_read(req, iter); |
| |
| if (!ret) { |
| goto done; |
| } else if (ret == -EIOCBQUEUED) { |
| ret = 0; |
| goto out_free; |
| } else if (ret == -EAGAIN) { |
| /* IOPOLL retry should happen for io-wq threads */ |
| if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| goto done; |
| /* no retry on NONBLOCK marked file */ |
| if (req->file->f_flags & O_NONBLOCK) |
| goto done; |
| /* some cases will consume bytes even on error returns */ |
| iov_iter_revert(iter, iov_count - iov_iter_count(iter)); |
| ret = 0; |
| goto copy_iov; |
| } else if (ret < 0) { |
| /* make sure -ERESTARTSYS -> -EINTR is done */ |
| goto done; |
| } |
| |
| /* read it all, or we did blocking attempt. no retry. */ |
| if (!iov_iter_count(iter) || !force_nonblock || |
| (req->file->f_flags & O_NONBLOCK)) |
| goto done; |
| |
| io_size -= ret; |
| copy_iov: |
| ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true); |
| if (ret2) { |
| ret = ret2; |
| goto out_free; |
| } |
| if (no_async) |
| return -EAGAIN; |
| /* it's copied and will be cleaned with ->io */ |
| iovec = NULL; |
| /* now use our persistent iterator, if we aren't already */ |
| iter = &req->io->rw.iter; |
| retry: |
| req->io->rw.bytes_done += ret; |
| /* if we can retry, do so with the callbacks armed */ |
| if (!io_rw_should_retry(req)) { |
| kiocb->ki_flags &= ~IOCB_WAITQ; |
| return -EAGAIN; |
| } |
| |
| /* |
| * Now retry read with the IOCB_WAITQ parts set in the iocb. If we |
| * get -EIOCBQUEUED, then we'll get a notification when the desired |
| * page gets unlocked. We can also get a partial read here, and if we |
| * do, then just retry at the new offset. |
| */ |
| ret = io_iter_do_read(req, iter); |
| if (ret == -EIOCBQUEUED) { |
| ret = 0; |
| goto out_free; |
| } else if (ret > 0 && ret < io_size) { |
| /* we got some bytes, but not all. retry. */ |
| goto retry; |
| } |
| done: |
| kiocb_done(kiocb, ret, cs); |
| ret = 0; |
| out_free: |
| /* it's reportedly faster than delegating the null check to kfree() */ |
| if (iovec) |
| kfree(iovec); |
| return ret; |
| } |
| |
| static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
| bool force_nonblock) |
| { |
| ssize_t ret; |
| |
| ret = io_prep_rw(req, sqe, force_nonblock); |
| if (ret) |
| return ret; |
| |
| if (unlikely(!(req->file->f_mode & FMODE_WRITE))) |
| return -EBADF; |
| |
| /* either don't need iovec imported or already have it */ |
| if (!req->io || req->flags & REQ_F_NEED_CLEANUP) |
| return 0; |
| return io_rw_prep_async(req, WRITE, force_nonblock); |
| } |
| |
| static int io_write(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; |
| struct kiocb *kiocb = &req->rw.kiocb; |
| struct iov_iter __iter, *iter = &__iter; |
| size_t iov_count; |
| ssize_t ret, ret2, io_size; |
| |
| if (req->io) |
| iter = &req->io->rw.iter; |
| |
| ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock); |
| if (ret < 0) |
| return ret; |
| iov_count = iov_iter_count(iter); |
| io_size = ret; |
| req->result = io_size; |
| |
| /* Ensure we clear previously set non-block flag */ |
| if (!force_nonblock) |
| req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT; |
| |
| /* If the file doesn't support async, just async punt */ |
| if (force_nonblock && !io_file_supports_async(req->file, WRITE)) |
| goto copy_iov; |
| |
| /* file path doesn't support NOWAIT for non-direct_IO */ |
| if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) && |
| (req->flags & REQ_F_ISREG)) |
| goto copy_iov; |
| |
| ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), iov_count); |
| if (unlikely(ret)) |
| goto out_free; |
| |
| /* |
| * Open-code file_start_write here to grab freeze protection, |
| * which will be released by another thread in |
| * io_complete_rw(). Fool lockdep by telling it the lock got |
| * released so that it doesn't complain about the held lock when |
| * we return to userspace. |
| */ |
| if (req->flags & REQ_F_ISREG) { |
| __sb_start_write(file_inode(req->file)->i_sb, |
| SB_FREEZE_WRITE, true); |
| __sb_writers_release(file_inode(req->file)->i_sb, |
| SB_FREEZE_WRITE); |
| } |
| kiocb->ki_flags |= IOCB_WRITE; |
| |
| if (req->file->f_op->write_iter) |
| ret2 = call_write_iter(req->file, kiocb, iter); |
| else if (req->file->f_op->write) |
| ret2 = loop_rw_iter(WRITE, req->file, kiocb, iter); |
| else |
| ret2 = -EINVAL; |
| |
| /* |
| * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just |
| * retry them without IOCB_NOWAIT. |
| */ |
| if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) |
| ret2 = -EAGAIN; |
| /* no retry on NONBLOCK marked file */ |
| if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK)) |
| goto done; |
| if (!force_nonblock || ret2 != -EAGAIN) { |
| /* IOPOLL retry should happen for io-wq threads */ |
| if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN) |
| goto copy_iov; |
| done: |
| kiocb_done(kiocb, ret2, cs); |
| } else { |
| copy_iov: |
| /* some cases will consume bytes even on error returns */ |
| iov_iter_revert(iter, iov_count - iov_iter_count(iter)); |
| ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false); |
| if (!ret) |
| return -EAGAIN; |
| } |
| out_free: |
| /* it's reportedly faster than delegating the null check to kfree() */ |
| if (iovec) |
| kfree(iovec); |
| return ret; |
| } |
| |
| static int __io_splice_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| struct io_splice* sp = &req->splice; |
| unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL; |
| int ret; |
| |
| if (req->flags & REQ_F_NEED_CLEANUP) |
| return 0; |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| |
| sp->file_in = NULL; |
| sp->len = READ_ONCE(sqe->len); |
| sp->flags = READ_ONCE(sqe->splice_flags); |
| |
| if (unlikely(sp->flags & ~valid_flags)) |
| return -EINVAL; |
| |
| ret = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in), &sp->file_in, |
| (sp->flags & SPLICE_F_FD_IN_FIXED)); |
| if (ret) |
| return ret; |
| req->flags |= REQ_F_NEED_CLEANUP; |
| |
| if (!S_ISREG(file_inode(sp->file_in)->i_mode)) { |
| /* |
| * Splice operation will be punted aync, and here need to |
| * modify io_wq_work.flags, so initialize io_wq_work firstly. |
| */ |
| io_req_init_async(req); |
| req->work.flags |= IO_WQ_WORK_UNBOUND; |
| } |
| |
| return 0; |
| } |
| |
| static int io_tee_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off)) |
| return -EINVAL; |
| return __io_splice_prep(req, sqe); |
| } |
| |
| static int io_tee(struct io_kiocb *req, bool force_nonblock) |
| { |
| struct io_splice *sp = &req->splice; |
| struct file *in = sp->file_in; |
| struct file *out = sp->file_out; |
| unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED; |
| long ret = 0; |
| |
| if (force_nonblock) |
| return -EAGAIN; |
| if (sp->len) |
| ret = do_tee(in, out, sp->len, flags); |
| |
| io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED)); |
| req->flags &= ~REQ_F_NEED_CLEANUP; |
| |
| if (ret != sp->len) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct io_splice* sp = &req->splice; |
| |
| sp->off_in = READ_ONCE(sqe->splice_off_in); |
| sp->off_out = READ_ONCE(sqe->off); |
| return __io_splice_prep(req, sqe); |
| } |
| |
| static int io_splice(struct io_kiocb *req, bool force_nonblock) |
| { |
| struct io_splice *sp = &req->splice; |
| struct file *in = sp->file_in; |
| struct file *out = sp->file_out; |
| unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED; |
| loff_t *poff_in, *poff_out; |
| long ret = 0; |
| |
| if (force_nonblock) |
| return -EAGAIN; |
| |
| poff_in = (sp->off_in == -1) ? NULL : &sp->off_in; |
| poff_out = (sp->off_out == -1) ? NULL : &sp->off_out; |
| |
| if (sp->len) |
| ret = do_splice(in, poff_in, out, poff_out, sp->len, flags); |
| |
| io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED)); |
| req->flags &= ~REQ_F_NEED_CLEANUP; |
| |
| if (ret != sp->len) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| /* |
| * IORING_OP_NOP just posts a completion event, nothing else. |
| */ |
| static int io_nop(struct io_kiocb *req, struct io_comp_state *cs) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| |
| __io_req_complete(req, 0, 0, cs); |
| return 0; |
| } |
| |
| static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| if (!req->file) |
| return -EBADF; |
| |
| if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) |
| return -EINVAL; |
| |
| req->sync.flags = READ_ONCE(sqe->fsync_flags); |
| if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC)) |
| return -EINVAL; |
| |
| req->sync.off = READ_ONCE(sqe->off); |
| req->sync.len = READ_ONCE(sqe->len); |
| return 0; |
| } |
| |
| static int io_fsync(struct io_kiocb *req, bool force_nonblock) |
| { |
| loff_t end = req->sync.off + req->sync.len; |
| int ret; |
| |
| /* fsync always requires a blocking context */ |
| if (force_nonblock) |
| return -EAGAIN; |
| |
| ret = vfs_fsync_range(req->file, req->sync.off, |
| end > 0 ? end : LLONG_MAX, |
| req->sync.flags & IORING_FSYNC_DATASYNC); |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| static int io_fallocate_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| if (sqe->ioprio || sqe->buf_index || sqe->rw_flags) |
| return -EINVAL; |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| |
| req->sync.off = READ_ONCE(sqe->off); |
| req->sync.len = READ_ONCE(sqe->addr); |
| req->sync.mode = READ_ONCE(sqe->len); |
| return 0; |
| } |
| |
| static int io_fallocate(struct io_kiocb *req, bool force_nonblock) |
| { |
| int ret; |
| |
| /* fallocate always requiring blocking context */ |
| if (force_nonblock) |
| return -EAGAIN; |
| ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off, |
| req->sync.len); |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| const char __user *fname; |
| int ret; |
| |
| if (unlikely(sqe->ioprio || sqe->buf_index)) |
| return -EINVAL; |
| if (unlikely(req->flags & REQ_F_FIXED_FILE)) |
| return -EBADF; |
| |
| /* open.how should be already initialised */ |
| if (!(req->open.how.flags & O_PATH) && force_o_largefile()) |
| req->open.how.flags |= O_LARGEFILE; |
| |
| req->open.dfd = READ_ONCE(sqe->fd); |
| fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
| req->open.filename = getname(fname); |
| if (IS_ERR(req->open.filename)) { |
| ret = PTR_ERR(req->open.filename); |
| req->open.filename = NULL; |
| return ret; |
| } |
| req->open.nofile = rlimit(RLIMIT_NOFILE); |
| req->flags |= REQ_F_NEED_CLEANUP; |
| return 0; |
| } |
| |
| static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| u64 flags, mode; |
| |
| if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) |
| return -EINVAL; |
| if (req->flags & REQ_F_NEED_CLEANUP) |
| return 0; |
| mode = READ_ONCE(sqe->len); |
| flags = READ_ONCE(sqe->open_flags); |
| req->open.how = build_open_how(flags, mode); |
| return __io_openat_prep(req, sqe); |
| } |
| |
| static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct open_how __user *how; |
| size_t len; |
| int ret; |
| |
| if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) |
| return -EINVAL; |
| if (req->flags & REQ_F_NEED_CLEANUP) |
| return 0; |
| how = u64_to_user_ptr(READ_ONCE(sqe->addr2)); |
| len = READ_ONCE(sqe->len); |
| if (len < OPEN_HOW_SIZE_VER0) |
| return -EINVAL; |
| |
| ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how, |
| len); |
| if (ret) |
| return ret; |
| |
| return __io_openat_prep(req, sqe); |
| } |
| |
| static int io_openat2(struct io_kiocb *req, bool force_nonblock) |
| { |
| struct open_flags op; |
| struct file *file; |
| int ret; |
| |
| if (force_nonblock) |
| return -EAGAIN; |
| |
| ret = build_open_flags(&req->open.how, &op); |
| if (ret) |
| goto err; |
| |
| ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile); |
| if (ret < 0) |
| goto err; |
| |
| file = do_filp_open(req->open.dfd, req->open.filename, &op); |
| if (IS_ERR(file)) { |
| put_unused_fd(ret); |
| ret = PTR_ERR(file); |
| } else { |
| fsnotify_open(file); |
| fd_install(ret, file); |
| } |
| err: |
| putname(req->open.filename); |
| req->flags &= ~REQ_F_NEED_CLEANUP; |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| static int io_openat(struct io_kiocb *req, bool force_nonblock) |
| { |
| return io_openat2(req, force_nonblock); |
| } |
| |
| static int io_remove_buffers_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| struct io_provide_buf *p = &req->pbuf; |
| u64 tmp; |
| |
| if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off) |
| return -EINVAL; |
| |
| tmp = READ_ONCE(sqe->fd); |
| if (!tmp || tmp > USHRT_MAX) |
| return -EINVAL; |
| |
| memset(p, 0, sizeof(*p)); |
| p->nbufs = tmp; |
| p->bgid = READ_ONCE(sqe->buf_group); |
| return 0; |
| } |
| |
| static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf, |
| int bgid, unsigned nbufs) |
| { |
| unsigned i = 0; |
| |
| /* shouldn't happen */ |
| if (!nbufs) |
| return 0; |
| |
| /* the head kbuf is the list itself */ |
| while (!list_empty(&buf->list)) { |
| struct io_buffer *nxt; |
| |
| nxt = list_first_entry(&buf->list, struct io_buffer, list); |
| list_del(&nxt->list); |
| kfree(nxt); |
| if (++i == nbufs) |
| return i; |
| } |
| i++; |
| kfree(buf); |
| idr_remove(&ctx->io_buffer_idr, bgid); |
| |
| return i; |
| } |
| |
| static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_provide_buf *p = &req->pbuf; |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_buffer *head; |
| int ret = 0; |
| |
| io_ring_submit_lock(ctx, !force_nonblock); |
| |
| lockdep_assert_held(&ctx->uring_lock); |
| |
| ret = -ENOENT; |
| head = idr_find(&ctx->io_buffer_idr, p->bgid); |
| if (head) |
| ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs); |
| |
| io_ring_submit_lock(ctx, !force_nonblock); |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| } |
| |
| static int io_provide_buffers_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| struct io_provide_buf *p = &req->pbuf; |
| u64 tmp; |
| |
| if (sqe->ioprio || sqe->rw_flags) |
| return -EINVAL; |
| |
| tmp = READ_ONCE(sqe->fd); |
| if (!tmp || tmp > USHRT_MAX) |
| return -E2BIG; |
| p->nbufs = tmp; |
| p->addr = READ_ONCE(sqe->addr); |
| p->len = READ_ONCE(sqe->len); |
| |
| if (!access_ok(u64_to_user_ptr(p->addr), (p->len * p->nbufs))) |
| return -EFAULT; |
| |
| p->bgid = READ_ONCE(sqe->buf_group); |
| tmp = READ_ONCE(sqe->off); |
| if (tmp > USHRT_MAX) |
| return -E2BIG; |
| p->bid = tmp; |
| return 0; |
| } |
| |
| static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head) |
| { |
| struct io_buffer *buf; |
| u64 addr = pbuf->addr; |
| int i, bid = pbuf->bid; |
| |
| for (i = 0; i < pbuf->nbufs; i++) { |
| buf = kmalloc(sizeof(*buf), GFP_KERNEL); |
| if (!buf) |
| break; |
| |
| buf->addr = addr; |
| buf->len = pbuf->len; |
| buf->bid = bid; |
| addr += pbuf->len; |
| bid++; |
| if (!*head) { |
| INIT_LIST_HEAD(&buf->list); |
| *head = buf; |
| } else { |
| list_add_tail(&buf->list, &(*head)->list); |
| } |
| } |
| |
| return i ? i : -ENOMEM; |
| } |
| |
| static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_provide_buf *p = &req->pbuf; |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_buffer *head, *list; |
| int ret = 0; |
| |
| io_ring_submit_lock(ctx, !force_nonblock); |
| |
| lockdep_assert_held(&ctx->uring_lock); |
| |
| list = head = idr_find(&ctx->io_buffer_idr, p->bgid); |
| |
| ret = io_add_buffers(p, &head); |
| if (ret < 0) |
| goto out; |
| |
| if (!list) { |
| ret = idr_alloc(&ctx->io_buffer_idr, head, p->bgid, p->bgid + 1, |
| GFP_KERNEL); |
| if (ret < 0) { |
| __io_remove_buffers(ctx, head, p->bgid, -1U); |
| goto out; |
| } |
| } |
| out: |
| io_ring_submit_unlock(ctx, !force_nonblock); |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| } |
| |
| static int io_epoll_ctl_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| #if defined(CONFIG_EPOLL) |
| if (sqe->ioprio || sqe->buf_index) |
| return -EINVAL; |
| if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL))) |
| return -EINVAL; |
| |
| req->epoll.epfd = READ_ONCE(sqe->fd); |
| req->epoll.op = READ_ONCE(sqe->len); |
| req->epoll.fd = READ_ONCE(sqe->off); |
| |
| if (ep_op_has_event(req->epoll.op)) { |
| struct epoll_event __user *ev; |
| |
| ev = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
| if (copy_from_user(&req->epoll.event, ev, sizeof(*ev))) |
| return -EFAULT; |
| } |
| |
| return 0; |
| #else |
| return -EOPNOTSUPP; |
| #endif |
| } |
| |
| static int io_epoll_ctl(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| #if defined(CONFIG_EPOLL) |
| struct io_epoll *ie = &req->epoll; |
| int ret; |
| |
| ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock); |
| if (force_nonblock && ret == -EAGAIN) |
| return -EAGAIN; |
| |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| #else |
| return -EOPNOTSUPP; |
| #endif |
| } |
| |
| static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) |
| if (sqe->ioprio || sqe->buf_index || sqe->off) |
| return -EINVAL; |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| |
| req->madvise.addr = READ_ONCE(sqe->addr); |
| req->madvise.len = READ_ONCE(sqe->len); |
| req->madvise.advice = READ_ONCE(sqe->fadvise_advice); |
| return 0; |
| #else |
| return -EOPNOTSUPP; |
| #endif |
| } |
| |
| static int io_madvise(struct io_kiocb *req, bool force_nonblock) |
| { |
| #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) |
| struct io_madvise *ma = &req->madvise; |
| int ret; |
| |
| if (force_nonblock) |
| return -EAGAIN; |
| |
| ret = do_madvise(ma->addr, ma->len, ma->advice); |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| #else |
| return -EOPNOTSUPP; |
| #endif |
| } |
| |
| static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| if (sqe->ioprio || sqe->buf_index || sqe->addr) |
| return -EINVAL; |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| |
| req->fadvise.offset = READ_ONCE(sqe->off); |
| req->fadvise.len = READ_ONCE(sqe->len); |
| req->fadvise.advice = READ_ONCE(sqe->fadvise_advice); |
| return 0; |
| } |
| |
| static int io_fadvise(struct io_kiocb *req, bool force_nonblock) |
| { |
| struct io_fadvise *fa = &req->fadvise; |
| int ret; |
| |
| if (force_nonblock) { |
| switch (fa->advice) { |
| case POSIX_FADV_NORMAL: |
| case POSIX_FADV_RANDOM: |
| case POSIX_FADV_SEQUENTIAL: |
| break; |
| default: |
| return -EAGAIN; |
| } |
| } |
| |
| ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice); |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL))) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->buf_index) |
| return -EINVAL; |
| if (req->flags & REQ_F_FIXED_FILE) |
| return -EBADF; |
| |
| req->statx.dfd = READ_ONCE(sqe->fd); |
| req->statx.mask = READ_ONCE(sqe->len); |
| req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
| req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2)); |
| req->statx.flags = READ_ONCE(sqe->statx_flags); |
| |
| return 0; |
| } |
| |
| static int io_statx(struct io_kiocb *req, bool force_nonblock) |
| { |
| struct io_statx *ctx = &req->statx; |
| int ret; |
| |
| if (force_nonblock) { |
| /* only need file table for an actual valid fd */ |
| if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD) |
| req->flags |= REQ_F_NO_FILE_TABLE; |
| return -EAGAIN; |
| } |
| |
| ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask, |
| ctx->buffer); |
| |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| /* |
| * If we queue this for async, it must not be cancellable. That would |
| * leave the 'file' in an undeterminate state, and here need to modify |
| * io_wq_work.flags, so initialize io_wq_work firstly. |
| */ |
| io_req_init_async(req); |
| req->work.flags |= IO_WQ_WORK_NO_CANCEL; |
| |
| if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->off || sqe->addr || sqe->len || |
| sqe->rw_flags || sqe->buf_index) |
| return -EINVAL; |
| if (req->flags & REQ_F_FIXED_FILE) |
| return -EBADF; |
| |
| req->close.fd = READ_ONCE(sqe->fd); |
| if ((req->file && req->file->f_op == &io_uring_fops) || |
| req->close.fd == req->ctx->ring_fd) |
| return -EBADF; |
| |
| req->close.put_file = NULL; |
| return 0; |
| } |
| |
| static int io_close(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_close *close = &req->close; |
| int ret; |
| |
| /* might be already done during nonblock submission */ |
| if (!close->put_file) { |
| ret = __close_fd_get_file(close->fd, &close->put_file); |
| if (ret < 0) |
| return (ret == -ENOENT) ? -EBADF : ret; |
| } |
| |
| /* if the file has a flush method, be safe and punt to async */ |
| if (close->put_file->f_op->flush && force_nonblock) { |
| /* was never set, but play safe */ |
| req->flags &= ~REQ_F_NOWAIT; |
| /* avoid grabbing files - we don't need the files */ |
| req->flags |= REQ_F_NO_FILE_TABLE; |
| return -EAGAIN; |
| } |
| |
| /* No ->flush() or already async, safely close from here */ |
| ret = filp_close(close->put_file, req->work.files); |
| if (ret < 0) |
| req_set_fail_links(req); |
| fput(close->put_file); |
| close->put_file = NULL; |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| } |
| |
| static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| if (!req->file) |
| return -EBADF; |
| |
| if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) |
| return -EINVAL; |
| |
| req->sync.off = READ_ONCE(sqe->off); |
| req->sync.len = READ_ONCE(sqe->len); |
| req->sync.flags = READ_ONCE(sqe->sync_range_flags); |
| return 0; |
| } |
| |
| static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock) |
| { |
| int ret; |
| |
| /* sync_file_range always requires a blocking context */ |
| if (force_nonblock) |
| return -EAGAIN; |
| |
| ret = sync_file_range(req->file, req->sync.off, req->sync.len, |
| req->sync.flags); |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| #if defined(CONFIG_NET) |
| static int io_setup_async_msg(struct io_kiocb *req, |
| struct io_async_msghdr *kmsg) |
| { |
| if (req->io) |
| return -EAGAIN; |
| if (io_alloc_async_ctx(req)) { |
| if (kmsg->iov != kmsg->fast_iov) |
| kfree(kmsg->iov); |
| return -ENOMEM; |
| } |
| req->flags |= REQ_F_NEED_CLEANUP; |
| memcpy(&req->io->msg, kmsg, sizeof(*kmsg)); |
| return -EAGAIN; |
| } |
| |
| static int io_sendmsg_copy_hdr(struct io_kiocb *req, |
| struct io_async_msghdr *iomsg) |
| { |
| iomsg->iov = iomsg->fast_iov; |
| iomsg->msg.msg_name = &iomsg->addr; |
| return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg, |
| req->sr_msg.msg_flags, &iomsg->iov); |
| } |
| |
| static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct io_sr_msg *sr = &req->sr_msg; |
| struct io_async_ctx *io = req->io; |
| int ret; |
| |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| |
| sr->msg_flags = READ_ONCE(sqe->msg_flags); |
| sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
| sr->len = READ_ONCE(sqe->len); |
| |
| #ifdef CONFIG_COMPAT |
| if (req->ctx->compat) |
| sr->msg_flags |= MSG_CMSG_COMPAT; |
| #endif |
| |
| if (!io || req->opcode == IORING_OP_SEND) |
| return 0; |
| /* iovec is already imported */ |
| if (req->flags & REQ_F_NEED_CLEANUP) |
| return 0; |
| |
| ret = io_sendmsg_copy_hdr(req, &io->msg); |
| if (!ret) |
| req->flags |= REQ_F_NEED_CLEANUP; |
| return ret; |
| } |
| |
| static int io_sendmsg(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_async_msghdr iomsg, *kmsg; |
| struct socket *sock; |
| unsigned flags; |
| int ret; |
| |
| sock = sock_from_file(req->file, &ret); |
| if (unlikely(!sock)) |
| return ret; |
| |
| if (req->io) { |
| kmsg = &req->io->msg; |
| kmsg->msg.msg_name = &req->io->msg.addr; |
| /* if iov is set, it's allocated already */ |
| if (!kmsg->iov) |
| kmsg->iov = kmsg->fast_iov; |
| kmsg->msg.msg_iter.iov = kmsg->iov; |
| } else { |
| ret = io_sendmsg_copy_hdr(req, &iomsg); |
| if (ret) |
| return ret; |
| kmsg = &iomsg; |
| } |
| |
| flags = req->sr_msg.msg_flags; |
| if (flags & MSG_DONTWAIT) |
| req->flags |= REQ_F_NOWAIT; |
| else if (force_nonblock) |
| flags |= MSG_DONTWAIT; |
| |
| ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags); |
| if (force_nonblock && ret == -EAGAIN) |
| return io_setup_async_msg(req, kmsg); |
| if (ret == -ERESTARTSYS) |
| ret = -EINTR; |
| |
| if (kmsg->iov != kmsg->fast_iov) |
| kfree(kmsg->iov); |
| req->flags &= ~REQ_F_NEED_CLEANUP; |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| } |
| |
| static int io_send(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_sr_msg *sr = &req->sr_msg; |
| struct msghdr msg; |
| struct iovec iov; |
| struct socket *sock; |
| unsigned flags; |
| int ret; |
| |
| sock = sock_from_file(req->file, &ret); |
| if (unlikely(!sock)) |
| return ret; |
| |
| ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter); |
| if (unlikely(ret)) |
| return ret;; |
| |
| msg.msg_name = NULL; |
| msg.msg_control = NULL; |
| msg.msg_controllen = 0; |
| msg.msg_namelen = 0; |
| |
| flags = req->sr_msg.msg_flags; |
| if (flags & MSG_DONTWAIT) |
| req->flags |= REQ_F_NOWAIT; |
| else if (force_nonblock) |
| flags |= MSG_DONTWAIT; |
| |
| msg.msg_flags = flags; |
| ret = sock_sendmsg(sock, &msg); |
| if (force_nonblock && ret == -EAGAIN) |
| return -EAGAIN; |
| if (ret == -ERESTARTSYS) |
| ret = -EINTR; |
| |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| } |
| |
| static int __io_recvmsg_copy_hdr(struct io_kiocb *req, |
| struct io_async_msghdr *iomsg) |
| { |
| struct io_sr_msg *sr = &req->sr_msg; |
| struct iovec __user *uiov; |
| size_t iov_len; |
| int ret; |
| |
| ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg, |
| &iomsg->uaddr, &uiov, &iov_len); |
| if (ret) |
| return ret; |
| |
| if (req->flags & REQ_F_BUFFER_SELECT) { |
| if (iov_len > 1) |
| return -EINVAL; |
| if (copy_from_user(iomsg->iov, uiov, sizeof(*uiov))) |
| return -EFAULT; |
| sr->len = iomsg->iov[0].iov_len; |
| iov_iter_init(&iomsg->msg.msg_iter, READ, iomsg->iov, 1, |
| sr->len); |
| iomsg->iov = NULL; |
| } else { |
| ret = import_iovec(READ, uiov, iov_len, UIO_FASTIOV, |
| &iomsg->iov, &iomsg->msg.msg_iter); |
| if (ret > 0) |
| ret = 0; |
| } |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_COMPAT |
| static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, |
| struct io_async_msghdr *iomsg) |
| { |
| struct compat_msghdr __user *msg_compat; |
| struct io_sr_msg *sr = &req->sr_msg; |
| struct compat_iovec __user *uiov; |
| compat_uptr_t ptr; |
| compat_size_t len; |
| int ret; |
| |
| msg_compat = (struct compat_msghdr __user *) sr->umsg; |
| ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr, |
| &ptr, &len); |
| if (ret) |
| return ret; |
| |
| uiov = compat_ptr(ptr); |
| if (req->flags & REQ_F_BUFFER_SELECT) { |
| compat_ssize_t clen; |
| |
| if (len > 1) |
| return -EINVAL; |
| if (!access_ok(uiov, sizeof(*uiov))) |
| return -EFAULT; |
| if (__get_user(clen, &uiov->iov_len)) |
| return -EFAULT; |
| if (clen < 0) |
| return -EINVAL; |
| sr->len = iomsg->iov[0].iov_len; |
| iomsg->iov = NULL; |
| } else { |
| ret = compat_import_iovec(READ, uiov, len, UIO_FASTIOV, |
| &iomsg->iov, |
| &iomsg->msg.msg_iter); |
| if (ret < 0) |
| return ret; |
| } |
| |
| return 0; |
| } |
| #endif |
| |
| static int io_recvmsg_copy_hdr(struct io_kiocb *req, |
| struct io_async_msghdr *iomsg) |
| { |
| iomsg->msg.msg_name = &iomsg->addr; |
| iomsg->iov = iomsg->fast_iov; |
| |
| #ifdef CONFIG_COMPAT |
| if (req->ctx->compat) |
| return __io_compat_recvmsg_copy_hdr(req, iomsg); |
| #endif |
| |
| return __io_recvmsg_copy_hdr(req, iomsg); |
| } |
| |
| static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req, |
| bool needs_lock) |
| { |
| struct io_sr_msg *sr = &req->sr_msg; |
| struct io_buffer *kbuf; |
| |
| kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock); |
| if (IS_ERR(kbuf)) |
| return kbuf; |
| |
| sr->kbuf = kbuf; |
| req->flags |= REQ_F_BUFFER_SELECTED; |
| return kbuf; |
| } |
| |
| static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req) |
| { |
| return io_put_kbuf(req, req->sr_msg.kbuf); |
| } |
| |
| static int io_recvmsg_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| struct io_sr_msg *sr = &req->sr_msg; |
| struct io_async_ctx *io = req->io; |
| int ret; |
| |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| |
| sr->msg_flags = READ_ONCE(sqe->msg_flags); |
| sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
| sr->len = READ_ONCE(sqe->len); |
| sr->bgid = READ_ONCE(sqe->buf_group); |
| |
| #ifdef CONFIG_COMPAT |
| if (req->ctx->compat) |
| sr->msg_flags |= MSG_CMSG_COMPAT; |
| #endif |
| |
| if (!io || req->opcode == IORING_OP_RECV) |
| return 0; |
| /* iovec is already imported */ |
| if (req->flags & REQ_F_NEED_CLEANUP) |
| return 0; |
| |
| ret = io_recvmsg_copy_hdr(req, &io->msg); |
| if (!ret) |
| req->flags |= REQ_F_NEED_CLEANUP; |
| return ret; |
| } |
| |
| static int io_recvmsg(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_async_msghdr iomsg, *kmsg; |
| struct socket *sock; |
| struct io_buffer *kbuf; |
| unsigned flags; |
| int ret, cflags = 0; |
| |
| sock = sock_from_file(req->file, &ret); |
| if (unlikely(!sock)) |
| return ret; |
| |
| if (req->io) { |
| kmsg = &req->io->msg; |
| kmsg->msg.msg_name = &req->io->msg.addr; |
| /* if iov is set, it's allocated already */ |
| if (!kmsg->iov) |
| kmsg->iov = kmsg->fast_iov; |
| kmsg->msg.msg_iter.iov = kmsg->iov; |
| } else { |
| ret = io_recvmsg_copy_hdr(req, &iomsg); |
| if (ret) |
| return ret; |
| kmsg = &iomsg; |
| } |
| |
| if (req->flags & REQ_F_BUFFER_SELECT) { |
| kbuf = io_recv_buffer_select(req, !force_nonblock); |
| if (IS_ERR(kbuf)) |
| return PTR_ERR(kbuf); |
| kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr); |
| iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov, |
| 1, req->sr_msg.len); |
| } |
| |
| flags = req->sr_msg.msg_flags; |
| if (flags & MSG_DONTWAIT) |
| req->flags |= REQ_F_NOWAIT; |
| else if (force_nonblock) |
| flags |= MSG_DONTWAIT; |
| |
| ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg, |
| kmsg->uaddr, flags); |
| if (force_nonblock && ret == -EAGAIN) |
| return io_setup_async_msg(req, kmsg); |
| if (ret == -ERESTARTSYS) |
| ret = -EINTR; |
| |
| if (req->flags & REQ_F_BUFFER_SELECTED) |
| cflags = io_put_recv_kbuf(req); |
| if (kmsg->iov != kmsg->fast_iov) |
| kfree(kmsg->iov); |
| req->flags &= ~REQ_F_NEED_CLEANUP; |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, cflags, cs); |
| return 0; |
| } |
| |
| static int io_recv(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_buffer *kbuf; |
| struct io_sr_msg *sr = &req->sr_msg; |
| struct msghdr msg; |
| void __user *buf = sr->buf; |
| struct socket *sock; |
| struct iovec iov; |
| unsigned flags; |
| int ret, cflags = 0; |
| |
| sock = sock_from_file(req->file, &ret); |
| if (unlikely(!sock)) |
| return ret; |
| |
| if (req->flags & REQ_F_BUFFER_SELECT) { |
| kbuf = io_recv_buffer_select(req, !force_nonblock); |
| if (IS_ERR(kbuf)) |
| return PTR_ERR(kbuf); |
| buf = u64_to_user_ptr(kbuf->addr); |
| } |
| |
| ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter); |
| if (unlikely(ret)) |
| goto out_free; |
| |
| msg.msg_name = NULL; |
| msg.msg_control = NULL; |
| msg.msg_controllen = 0; |
| msg.msg_namelen = 0; |
| msg.msg_iocb = NULL; |
| msg.msg_flags = 0; |
| |
| flags = req->sr_msg.msg_flags; |
| if (flags & MSG_DONTWAIT) |
| req->flags |= REQ_F_NOWAIT; |
| else if (force_nonblock) |
| flags |= MSG_DONTWAIT; |
| |
| ret = sock_recvmsg(sock, &msg, flags); |
| if (force_nonblock && ret == -EAGAIN) |
| return -EAGAIN; |
| if (ret == -ERESTARTSYS) |
| ret = -EINTR; |
| out_free: |
| if (req->flags & REQ_F_BUFFER_SELECTED) |
| cflags = io_put_recv_kbuf(req); |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, cflags, cs); |
| return 0; |
| } |
| |
| static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct io_accept *accept = &req->accept; |
| |
| if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->len || sqe->buf_index) |
| return -EINVAL; |
| |
| accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
| accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2)); |
| accept->flags = READ_ONCE(sqe->accept_flags); |
| accept->nofile = rlimit(RLIMIT_NOFILE); |
| return 0; |
| } |
| |
| static int io_accept(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_accept *accept = &req->accept; |
| unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0; |
| int ret; |
| |
| if (req->file->f_flags & O_NONBLOCK) |
| req->flags |= REQ_F_NOWAIT; |
| |
| ret = __sys_accept4_file(req->file, file_flags, accept->addr, |
| accept->addr_len, accept->flags, |
| accept->nofile); |
| if (ret == -EAGAIN && force_nonblock) |
| return -EAGAIN; |
| if (ret < 0) { |
| if (ret == -ERESTARTSYS) |
| ret = -EINTR; |
| req_set_fail_links(req); |
| } |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| } |
| |
| static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct io_connect *conn = &req->connect; |
| struct io_async_ctx *io = req->io; |
| |
| if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags) |
| return -EINVAL; |
| |
| conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
| conn->addr_len = READ_ONCE(sqe->addr2); |
| |
| if (!io) |
| return 0; |
| |
| return move_addr_to_kernel(conn->addr, conn->addr_len, |
| &io->connect.address); |
| } |
| |
| static int io_connect(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_async_ctx __io, *io; |
| unsigned file_flags; |
| int ret; |
| |
| if (req->io) { |
| io = req->io; |
| } else { |
| ret = move_addr_to_kernel(req->connect.addr, |
| req->connect.addr_len, |
| &__io.connect.address); |
| if (ret) |
| goto out; |
| io = &__io; |
| } |
| |
| file_flags = force_nonblock ? O_NONBLOCK : 0; |
| |
| ret = __sys_connect_file(req->file, &io->connect.address, |
| req->connect.addr_len, file_flags); |
| if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) { |
| if (req->io) |
| return -EAGAIN; |
| if (io_alloc_async_ctx(req)) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| memcpy(&req->io->connect, &__io.connect, sizeof(__io.connect)); |
| return -EAGAIN; |
| } |
| if (ret == -ERESTARTSYS) |
| ret = -EINTR; |
| out: |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| } |
| #else /* !CONFIG_NET */ |
| static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_sendmsg(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_send(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_recvmsg_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_recvmsg(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_recv(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_accept(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static int io_connect(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| return -EOPNOTSUPP; |
| } |
| #endif /* CONFIG_NET */ |
| |
| struct io_poll_table { |
| struct poll_table_struct pt; |
| struct io_kiocb *req; |
| int error; |
| }; |
| |
| static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll, |
| __poll_t mask, task_work_func_t func) |
| { |
| bool twa_signal_ok; |
| int ret; |
| |
| /* for instances that support it check for an event match first: */ |
| if (mask && !(mask & poll->events)) |
| return 0; |
| |
| trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask); |
| |
| list_del_init(&poll->wait.entry); |
| |
| req->result = mask; |
| init_task_work(&req->task_work, func); |
| percpu_ref_get(&req->ctx->refs); |
| |
| /* |
| * If we using the signalfd wait_queue_head for this wakeup, then |
| * it's not safe to use TWA_SIGNAL as we could be recursing on the |
| * tsk->sighand->siglock on doing the wakeup. Should not be needed |
| * either, as the normal wakeup will suffice. |
| */ |
| twa_signal_ok = (poll->head != &req->task->sighand->signalfd_wqh); |
| |
| /* |
| * If this fails, then the task is exiting. When a task exits, the |
| * work gets canceled, so just cancel this request as well instead |
| * of executing it. We can't safely execute it anyway, as we may not |
| * have the needed state needed for it anyway. |
| */ |
| ret = io_req_task_work_add(req, &req->task_work, twa_signal_ok); |
| if (unlikely(ret)) { |
| struct task_struct *tsk; |
| |
| WRITE_ONCE(poll->canceled, true); |
| tsk = io_wq_get_task(req->ctx->io_wq); |
| task_work_add(tsk, &req->task_work, 0); |
| wake_up_process(tsk); |
| } |
| return 1; |
| } |
| |
| static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll) |
| __acquires(&req->ctx->completion_lock) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| if (!req->result && !READ_ONCE(poll->canceled)) { |
| struct poll_table_struct pt = { ._key = poll->events }; |
| |
| req->result = vfs_poll(req->file, &pt) & poll->events; |
| } |
| |
| spin_lock_irq(&ctx->completion_lock); |
| if (!req->result && !READ_ONCE(poll->canceled)) { |
| add_wait_queue(poll->head, &poll->wait); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req) |
| { |
| /* pure poll stashes this in ->io, poll driven retry elsewhere */ |
| if (req->opcode == IORING_OP_POLL_ADD) |
| return (struct io_poll_iocb *) req->io; |
| return req->apoll->double_poll; |
| } |
| |
| static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req) |
| { |
| if (req->opcode == IORING_OP_POLL_ADD) |
| return &req->poll; |
| return &req->apoll->poll; |
| } |
| |
| static void io_poll_remove_double(struct io_kiocb *req) |
| { |
| struct io_poll_iocb *poll = io_poll_get_double(req); |
| |
| lockdep_assert_held(&req->ctx->completion_lock); |
| |
| if (poll && poll->head) { |
| struct wait_queue_head *head = poll->head; |
| |
| spin_lock(&head->lock); |
| list_del_init(&poll->wait.entry); |
| if (poll->wait.private) |
| refcount_dec(&req->refs); |
| poll->head = NULL; |
| spin_unlock(&head->lock); |
| } |
| } |
| |
| static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| io_poll_remove_double(req); |
| req->poll.done = true; |
| io_cqring_fill_event(req, error ? error : mangle_poll(mask)); |
| io_commit_cqring(ctx); |
| } |
| |
| static void io_poll_task_handler(struct io_kiocb *req, struct io_kiocb **nxt) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| if (io_poll_rewait(req, &req->poll)) { |
| spin_unlock_irq(&ctx->completion_lock); |
| return; |
| } |
| |
| hash_del(&req->hash_node); |
| io_poll_complete(req, req->result, 0); |
| req->flags |= REQ_F_COMP_LOCKED; |
| *nxt = io_put_req_find_next(req); |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| io_cqring_ev_posted(ctx); |
| } |
| |
| static void io_poll_task_func(struct callback_head *cb) |
| { |
| struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_kiocb *nxt = NULL; |
| |
| io_poll_task_handler(req, &nxt); |
| if (nxt) |
| __io_req_task_submit(nxt); |
| percpu_ref_put(&ctx->refs); |
| } |
| |
| static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode, |
| int sync, void *key) |
| { |
| struct io_kiocb *req = wait->private; |
| struct io_poll_iocb *poll = io_poll_get_single(req); |
| __poll_t mask = key_to_poll(key); |
| |
| /* for instances that support it check for an event match first: */ |
| if (mask && !(mask & poll->events)) |
| return 0; |
| |
| list_del_init(&wait->entry); |
| |
| if (poll && poll->head) { |
| bool done; |
| |
| spin_lock(&poll->head->lock); |
| done = list_empty(&poll->wait.entry); |
| if (!done) |
| list_del_init(&poll->wait.entry); |
| /* make sure double remove sees this as being gone */ |
| wait->private = NULL; |
| spin_unlock(&poll->head->lock); |
| if (!done) |
| __io_async_wake(req, poll, mask, io_poll_task_func); |
| } |
| refcount_dec(&req->refs); |
| return 1; |
| } |
| |
| static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events, |
| wait_queue_func_t wake_func) |
| { |
| poll->head = NULL; |
| poll->done = false; |
| poll->canceled = false; |
| poll->events = events; |
| INIT_LIST_HEAD(&poll->wait.entry); |
| init_waitqueue_func_entry(&poll->wait, wake_func); |
| } |
| |
| static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, |
| struct wait_queue_head *head, |
| struct io_poll_iocb **poll_ptr) |
| { |
| struct io_kiocb *req = pt->req; |
| |
| /* |
| * If poll->head is already set, it's because the file being polled |
| * uses multiple waitqueues for poll handling (eg one for read, one |
| * for write). Setup a separate io_poll_iocb if this happens. |
| */ |
| if (unlikely(poll->head)) { |
| /* already have a 2nd entry, fail a third attempt */ |
| if (*poll_ptr) { |
| pt->error = -EINVAL; |
| return; |
| } |
| poll = kmalloc(sizeof(*poll), GFP_ATOMIC); |
| if (!poll) { |
| pt->error = -ENOMEM; |
| return; |
| } |
| io_init_poll_iocb(poll, req->poll.events, io_poll_double_wake); |
| refcount_inc(&req->refs); |
| poll->wait.private = req; |
| *poll_ptr = poll; |
| } |
| |
| pt->error = 0; |
| poll->head = head; |
| |
| if (poll->events & EPOLLEXCLUSIVE) |
| add_wait_queue_exclusive(head, &poll->wait); |
| else |
| add_wait_queue(head, &poll->wait); |
| } |
| |
| static void io_async_queue_proc(struct file *file, struct wait_queue_head *head, |
| struct poll_table_struct *p) |
| { |
| struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); |
| struct async_poll *apoll = pt->req->apoll; |
| |
| __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll); |
| } |
| |
| static void io_async_task_func(struct callback_head *cb) |
| { |
| struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); |
| struct async_poll *apoll = req->apoll; |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| trace_io_uring_task_run(req->ctx, req->opcode, req->user_data); |
| |
| if (io_poll_rewait(req, &apoll->poll)) { |
| spin_unlock_irq(&ctx->completion_lock); |
| percpu_ref_put(&ctx->refs); |
| return; |
| } |
| |
| /* If req is still hashed, it cannot have been canceled. Don't check. */ |
| if (hash_hashed(&req->hash_node)) |
| hash_del(&req->hash_node); |
| |
| io_poll_remove_double(req); |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| if (!READ_ONCE(apoll->poll.canceled)) |
| __io_req_task_submit(req); |
| else |
| __io_req_task_cancel(req, -ECANCELED); |
| |
| percpu_ref_put(&ctx->refs); |
| kfree(apoll->double_poll); |
| kfree(apoll); |
| } |
| |
| static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync, |
| void *key) |
| { |
| struct io_kiocb *req = wait->private; |
| struct io_poll_iocb *poll = &req->apoll->poll; |
| |
| trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data, |
| key_to_poll(key)); |
| |
| return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func); |
| } |
| |
| static void io_poll_req_insert(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| struct hlist_head *list; |
| |
| list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)]; |
| hlist_add_head(&req->hash_node, list); |
| } |
| |
| static __poll_t __io_arm_poll_handler(struct io_kiocb *req, |
| struct io_poll_iocb *poll, |
| struct io_poll_table *ipt, __poll_t mask, |
| wait_queue_func_t wake_func) |
| __acquires(&ctx->completion_lock) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| bool cancel = false; |
| |
| io_init_poll_iocb(poll, mask, wake_func); |
| poll->file = req->file; |
| poll->wait.private = req; |
| |
| ipt->pt._key = mask; |
| ipt->req = req; |
| ipt->error = -EINVAL; |
| |
| mask = vfs_poll(req->file, &ipt->pt) & poll->events; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| if (likely(poll->head)) { |
| spin_lock(&poll->head->lock); |
| if (unlikely(list_empty(&poll->wait.entry))) { |
| if (ipt->error) |
| cancel = true; |
| ipt->error = 0; |
| mask = 0; |
| } |
| if (mask || ipt->error) |
| list_del_init(&poll->wait.entry); |
| else if (cancel) |
| WRITE_ONCE(poll->canceled, true); |
| else if (!poll->done) /* actually waiting for an event */ |
| io_poll_req_insert(req); |
| spin_unlock(&poll->head->lock); |
| } |
| |
| return mask; |
| } |
| |
| static bool io_arm_poll_handler(struct io_kiocb *req) |
| { |
| const struct io_op_def *def = &io_op_defs[req->opcode]; |
| struct io_ring_ctx *ctx = req->ctx; |
| struct async_poll *apoll; |
| struct io_poll_table ipt; |
| __poll_t mask, ret; |
| int rw; |
| |
| if (!req->file || !file_can_poll(req->file)) |
| return false; |
| if (req->flags & REQ_F_POLLED) |
| return false; |
| if (def->pollin) |
| rw = READ; |
| else if (def->pollout) |
| rw = WRITE; |
| else |
| return false; |
| /* if we can't nonblock try, then no point in arming a poll handler */ |
| if (!io_file_supports_async(req->file, rw)) |
| return false; |
| |
| apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC); |
| if (unlikely(!apoll)) |
| return false; |
| apoll->double_poll = NULL; |
| |
| req->flags |= REQ_F_POLLED; |
| io_get_req_task(req); |
| req->apoll = apoll; |
| INIT_HLIST_NODE(&req->hash_node); |
| |
| mask = 0; |
| if (def->pollin) |
| mask |= POLLIN | POLLRDNORM; |
| if (def->pollout) |
| mask |= POLLOUT | POLLWRNORM; |
| |
| /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */ |
| if ((req->opcode == IORING_OP_RECVMSG) && |
| (req->sr_msg.msg_flags & MSG_ERRQUEUE)) |
| mask &= ~POLLIN; |
| |
| mask |= POLLERR | POLLPRI; |
| |
| ipt.pt._qproc = io_async_queue_proc; |
| |
| ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask, |
| io_async_wake); |
| if (ret || ipt.error) { |
| io_poll_remove_double(req); |
| spin_unlock_irq(&ctx->completion_lock); |
| kfree(apoll->double_poll); |
| kfree(apoll); |
| return false; |
| } |
| spin_unlock_irq(&ctx->completion_lock); |
| trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask, |
| apoll->poll.events); |
| return true; |
| } |
| |
| static bool __io_poll_remove_one(struct io_kiocb *req, |
| struct io_poll_iocb *poll) |
| { |
| bool do_complete = false; |
| |
| spin_lock(&poll->head->lock); |
| WRITE_ONCE(poll->canceled, true); |
| if (!list_empty(&poll->wait.entry)) { |
| list_del_init(&poll->wait.entry); |
| do_complete = true; |
| } |
| spin_unlock(&poll->head->lock); |
| hash_del(&req->hash_node); |
| return do_complete; |
| } |
| |
| static bool io_poll_remove_one(struct io_kiocb *req) |
| { |
| bool do_complete; |
| |
| io_poll_remove_double(req); |
| |
| if (req->opcode == IORING_OP_POLL_ADD) { |
| do_complete = __io_poll_remove_one(req, &req->poll); |
| } else { |
| struct async_poll *apoll = req->apoll; |
| |
| /* non-poll requests have submit ref still */ |
| do_complete = __io_poll_remove_one(req, &apoll->poll); |
| if (do_complete) { |
| io_put_req(req); |
| kfree(apoll->double_poll); |
| kfree(apoll); |
| } |
| } |
| |
| if (do_complete) { |
| io_cqring_fill_event(req, -ECANCELED); |
| io_commit_cqring(req->ctx); |
| req->flags |= REQ_F_COMP_LOCKED; |
| req_set_fail_links(req); |
| io_put_req(req); |
| } |
| |
| return do_complete; |
| } |
| |
| static void io_poll_remove_all(struct io_ring_ctx *ctx) |
| { |
| struct hlist_node *tmp; |
| struct io_kiocb *req; |
| int posted = 0, i; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { |
| struct hlist_head *list; |
| |
| list = &ctx->cancel_hash[i]; |
| hlist_for_each_entry_safe(req, tmp, list, hash_node) |
| posted += io_poll_remove_one(req); |
| } |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| if (posted) |
| io_cqring_ev_posted(ctx); |
| } |
| |
| static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr) |
| { |
| struct hlist_head *list; |
| struct io_kiocb *req; |
| |
| list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)]; |
| hlist_for_each_entry(req, list, hash_node) { |
| if (sqe_addr != req->user_data) |
| continue; |
| if (io_poll_remove_one(req)) |
| return 0; |
| return -EALREADY; |
| } |
| |
| return -ENOENT; |
| } |
| |
| static int io_poll_remove_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index || |
| sqe->poll_events) |
| return -EINVAL; |
| |
| req->poll.addr = READ_ONCE(sqe->addr); |
| return 0; |
| } |
| |
| /* |
| * Find a running poll command that matches one specified in sqe->addr, |
| * and remove it if found. |
| */ |
| static int io_poll_remove(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| u64 addr; |
| int ret; |
| |
| addr = req->poll.addr; |
| spin_lock_irq(&ctx->completion_lock); |
| ret = io_poll_cancel(ctx, addr); |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| return 0; |
| } |
| |
| static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, |
| void *key) |
| { |
| struct io_kiocb *req = wait->private; |
| struct io_poll_iocb *poll = &req->poll; |
| |
| return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func); |
| } |
| |
| static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, |
| struct poll_table_struct *p) |
| { |
| struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); |
| |
| __io_queue_proc(&pt->req->poll, pt, head, (struct io_poll_iocb **) &pt->req->io); |
| } |
| |
| static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct io_poll_iocb *poll = &req->poll; |
| u32 events; |
| |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index) |
| return -EINVAL; |
| if (!poll->file) |
| return -EBADF; |
| |
| events = READ_ONCE(sqe->poll32_events); |
| #ifdef __BIG_ENDIAN |
| events = swahw32(events); |
| #endif |
| poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP | |
| (events & EPOLLEXCLUSIVE); |
| |
| io_get_req_task(req); |
| return 0; |
| } |
| |
| static int io_poll_add(struct io_kiocb *req) |
| { |
| struct io_poll_iocb *poll = &req->poll; |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_poll_table ipt; |
| __poll_t mask; |
| |
| INIT_HLIST_NODE(&req->hash_node); |
| ipt.pt._qproc = io_poll_queue_proc; |
| |
| mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events, |
| io_poll_wake); |
| |
| if (mask) { /* no async, we'd stolen it */ |
| ipt.error = 0; |
| io_poll_complete(req, mask, 0); |
| } |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| if (mask) { |
| io_cqring_ev_posted(ctx); |
| io_put_req(req); |
| } |
| return ipt.error; |
| } |
| |
| static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) |
| { |
| struct io_timeout_data *data = container_of(timer, |
| struct io_timeout_data, timer); |
| struct io_kiocb *req = data->req; |
| struct io_ring_ctx *ctx = req->ctx; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&ctx->completion_lock, flags); |
| atomic_set(&req->ctx->cq_timeouts, |
| atomic_read(&req->ctx->cq_timeouts) + 1); |
| |
| /* |
| * We could be racing with timeout deletion. If the list is empty, |
| * then timeout lookup already found it and will be handling it. |
| */ |
| if (!list_empty(&req->timeout.list)) |
| list_del_init(&req->timeout.list); |
| |
| io_cqring_fill_event(req, -ETIME); |
| io_commit_cqring(ctx); |
| spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| |
| io_cqring_ev_posted(ctx); |
| req_set_fail_links(req); |
| io_put_req(req); |
| return HRTIMER_NORESTART; |
| } |
| |
| static int __io_timeout_cancel(struct io_kiocb *req) |
| { |
| int ret; |
| |
| list_del_init(&req->timeout.list); |
| |
| ret = hrtimer_try_to_cancel(&req->io->timeout.timer); |
| if (ret == -1) |
| return -EALREADY; |
| |
| req_set_fail_links(req); |
| req->flags |= REQ_F_COMP_LOCKED; |
| io_cqring_fill_event(req, -ECANCELED); |
| io_put_req(req); |
| return 0; |
| } |
| |
| static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data) |
| { |
| struct io_kiocb *req; |
| int ret = -ENOENT; |
| |
| list_for_each_entry(req, &ctx->timeout_list, timeout.list) { |
| if (user_data == req->user_data) { |
| ret = 0; |
| break; |
| } |
| } |
| |
| if (ret == -ENOENT) |
| return ret; |
| |
| return __io_timeout_cancel(req); |
| } |
| |
| static int io_timeout_remove_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->buf_index || sqe->len) |
| return -EINVAL; |
| |
| req->timeout.addr = READ_ONCE(sqe->addr); |
| req->timeout.flags = READ_ONCE(sqe->timeout_flags); |
| if (req->timeout.flags) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| /* |
| * Remove or update an existing timeout command |
| */ |
| static int io_timeout_remove(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| int ret; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| ret = io_timeout_cancel(ctx, req->timeout.addr); |
| |
| io_cqring_fill_event(req, ret); |
| io_commit_cqring(ctx); |
| spin_unlock_irq(&ctx->completion_lock); |
| io_cqring_ev_posted(ctx); |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_put_req(req); |
| return 0; |
| } |
| |
| static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
| bool is_timeout_link) |
| { |
| struct io_timeout_data *data; |
| unsigned flags; |
| u32 off = READ_ONCE(sqe->off); |
| |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->buf_index || sqe->len != 1) |
| return -EINVAL; |
| if (off && is_timeout_link) |
| return -EINVAL; |
| flags = READ_ONCE(sqe->timeout_flags); |
| if (flags & ~IORING_TIMEOUT_ABS) |
| return -EINVAL; |
| |
| req->timeout.off = off; |
| |
| if (!req->io && io_alloc_async_ctx(req)) |
| return -ENOMEM; |
| |
| data = &req->io->timeout; |
| data->req = req; |
| |
| if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr))) |
| return -EFAULT; |
| |
| if (flags & IORING_TIMEOUT_ABS) |
| data->mode = HRTIMER_MODE_ABS; |
| else |
| data->mode = HRTIMER_MODE_REL; |
| |
| hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode); |
| return 0; |
| } |
| |
| static int io_timeout(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_timeout_data *data = &req->io->timeout; |
| struct list_head *entry; |
| u32 tail, off = req->timeout.off; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| |
| /* |
| * sqe->off holds how many events that need to occur for this |
| * timeout event to be satisfied. If it isn't set, then this is |
| * a pure timeout request, sequence isn't used. |
| */ |
| if (io_is_timeout_noseq(req)) { |
| entry = ctx->timeout_list.prev; |
| goto add; |
| } |
| |
| tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); |
| req->timeout.target_seq = tail + off; |
| |
| /* |
| * Insertion sort, ensuring the first entry in the list is always |
| * the one we need first. |
| */ |
| list_for_each_prev(entry, &ctx->timeout_list) { |
| struct io_kiocb *nxt = list_entry(entry, struct io_kiocb, |
| timeout.list); |
| |
| if (io_is_timeout_noseq(nxt)) |
| continue; |
| /* nxt.seq is behind @tail, otherwise would've been completed */ |
| if (off >= nxt->timeout.target_seq - tail) |
| break; |
| } |
| add: |
| list_add(&req->timeout.list, entry); |
| data->timer.function = io_timeout_fn; |
| hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode); |
| spin_unlock_irq(&ctx->completion_lock); |
| return 0; |
| } |
| |
| static bool io_cancel_cb(struct io_wq_work *work, void *data) |
| { |
| struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
| |
| return req->user_data == (unsigned long) data; |
| } |
| |
| static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr) |
| { |
| enum io_wq_cancel cancel_ret; |
| int ret = 0; |
| |
| cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr, false); |
| switch (cancel_ret) { |
| case IO_WQ_CANCEL_OK: |
| ret = 0; |
| break; |
| case IO_WQ_CANCEL_RUNNING: |
| ret = -EALREADY; |
| break; |
| case IO_WQ_CANCEL_NOTFOUND: |
| ret = -ENOENT; |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static void io_async_find_and_cancel(struct io_ring_ctx *ctx, |
| struct io_kiocb *req, __u64 sqe_addr, |
| int success_ret) |
| { |
| unsigned long flags; |
| int ret; |
| |
| ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr); |
| if (ret != -ENOENT) { |
| spin_lock_irqsave(&ctx->completion_lock, flags); |
| goto done; |
| } |
| |
| spin_lock_irqsave(&ctx->completion_lock, flags); |
| ret = io_timeout_cancel(ctx, sqe_addr); |
| if (ret != -ENOENT) |
| goto done; |
| ret = io_poll_cancel(ctx, sqe_addr); |
| done: |
| if (!ret) |
| ret = success_ret; |
| io_cqring_fill_event(req, ret); |
| io_commit_cqring(ctx); |
| spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| io_cqring_ev_posted(ctx); |
| |
| if (ret < 0) |
| req_set_fail_links(req); |
| io_put_req(req); |
| } |
| |
| static int io_async_cancel_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
| return -EINVAL; |
| if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags) |
| return -EINVAL; |
| |
| req->cancel.addr = READ_ONCE(sqe->addr); |
| return 0; |
| } |
| |
| static int io_async_cancel(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| io_async_find_and_cancel(ctx, req, req->cancel.addr, 0); |
| return 0; |
| } |
| |
| static int io_files_update_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| if (unlikely(req->ctx->flags & IORING_SETUP_SQPOLL)) |
| return -EINVAL; |
| if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) |
| return -EINVAL; |
| if (sqe->ioprio || sqe->rw_flags) |
| return -EINVAL; |
| |
| req->files_update.offset = READ_ONCE(sqe->off); |
| req->files_update.nr_args = READ_ONCE(sqe->len); |
| if (!req->files_update.nr_args) |
| return -EINVAL; |
| req->files_update.arg = READ_ONCE(sqe->addr); |
| return 0; |
| } |
| |
| static int io_files_update(struct io_kiocb *req, bool force_nonblock, |
| struct io_comp_state *cs) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_uring_files_update up; |
| int ret; |
| |
| if (force_nonblock) |
| return -EAGAIN; |
| |
| up.offset = req->files_update.offset; |
| up.fds = req->files_update.arg; |
| |
| mutex_lock(&ctx->uring_lock); |
| ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args); |
| mutex_unlock(&ctx->uring_lock); |
| |
| if (ret < 0) |
| req_set_fail_links(req); |
| __io_req_complete(req, ret, 0, cs); |
| return 0; |
| } |
| |
| static int io_req_defer_prep(struct io_kiocb *req, |
| const struct io_uring_sqe *sqe) |
| { |
| ssize_t ret = 0; |
| |
| if (!sqe) |
| return 0; |
| |
| if (io_alloc_async_ctx(req)) |
| return -EAGAIN; |
| ret = io_prep_work_files(req); |
| if (unlikely(ret)) |
| return ret; |
| |
| io_prep_async_work(req); |
| |
| switch (req->opcode) { |
| case IORING_OP_NOP: |
| break; |
| case IORING_OP_READV: |
| case IORING_OP_READ_FIXED: |
| case IORING_OP_READ: |
| ret = io_read_prep(req, sqe, true); |
| break; |
| case IORING_OP_WRITEV: |
| case IORING_OP_WRITE_FIXED: |
| case IORING_OP_WRITE: |
| ret = io_write_prep(req, sqe, true); |
| break; |
| case IORING_OP_POLL_ADD: |
| ret = io_poll_add_prep(req, sqe); |
| break; |
| case IORING_OP_POLL_REMOVE: |
| ret = io_poll_remove_prep(req, sqe); |
| break; |
| case IORING_OP_FSYNC: |
| ret = io_prep_fsync(req, sqe); |
| break; |
| case IORING_OP_SYNC_FILE_RANGE: |
| ret = io_prep_sfr(req, sqe); |
| break; |
| case IORING_OP_SENDMSG: |
| case IORING_OP_SEND: |
| ret = io_sendmsg_prep(req, sqe); |
| break; |
| case IORING_OP_RECVMSG: |
| case IORING_OP_RECV: |
| ret = io_recvmsg_prep(req, sqe); |
| break; |
| case IORING_OP_CONNECT: |
| ret = io_connect_prep(req, sqe); |
| break; |
| case IORING_OP_TIMEOUT: |
| ret = io_timeout_prep(req, sqe, false); |
| break; |
| case IORING_OP_TIMEOUT_REMOVE: |
| ret = io_timeout_remove_prep(req, sqe); |
| break; |
| case IORING_OP_ASYNC_CANCEL: |
| ret = io_async_cancel_prep(req, sqe); |
| break; |
| case IORING_OP_LINK_TIMEOUT: |
| ret = io_timeout_prep(req, sqe, true); |
| break; |
| case IORING_OP_ACCEPT: |
| ret = io_accept_prep(req, sqe); |
| break; |
| case IORING_OP_FALLOCATE: |
| ret = io_fallocate_prep(req, sqe); |
| break; |
| case IORING_OP_OPENAT: |
| ret = io_openat_prep(req, sqe); |
| break; |
| case IORING_OP_CLOSE: |
| ret = io_close_prep(req, sqe); |
| break; |
| case IORING_OP_FILES_UPDATE: |
| ret = io_files_update_prep(req, sqe); |
| break; |
| case IORING_OP_STATX: |
| ret = io_statx_prep(req, sqe); |
| break; |
| case IORING_OP_FADVISE: |
| ret = io_fadvise_prep(req, sqe); |
| break; |
| case IORING_OP_MADVISE: |
| ret = io_madvise_prep(req, sqe); |
| break; |
| case IORING_OP_OPENAT2: |
| ret = io_openat2_prep(req, sqe); |
| break; |
| case IORING_OP_EPOLL_CTL: |
| ret = io_epoll_ctl_prep(req, sqe); |
| break; |
| case IORING_OP_SPLICE: |
| ret = io_splice_prep(req, sqe); |
| break; |
| case IORING_OP_PROVIDE_BUFFERS: |
| ret = io_provide_buffers_prep(req, sqe); |
| break; |
| case IORING_OP_REMOVE_BUFFERS: |
| ret = io_remove_buffers_prep(req, sqe); |
| break; |
| case IORING_OP_TEE: |
| ret = io_tee_prep(req, sqe); |
| break; |
| default: |
| printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", |
| req->opcode); |
| ret = -EINVAL; |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static u32 io_get_sequence(struct io_kiocb *req) |
| { |
| struct io_kiocb *pos; |
| struct io_ring_ctx *ctx = req->ctx; |
| u32 total_submitted, nr_reqs = 1; |
| |
| if (req->flags & REQ_F_LINK_HEAD) |
| list_for_each_entry(pos, &req->link_list, link_list) |
| nr_reqs++; |
| |
| total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped; |
| return total_submitted - nr_reqs; |
| } |
| |
| static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_defer_entry *de; |
| int ret; |
| u32 seq; |
| |
| /* Still need defer if there is pending req in defer list. */ |
| if (likely(list_empty_careful(&ctx->defer_list) && |
| !(req->flags & REQ_F_IO_DRAIN))) |
| return 0; |
| |
| seq = io_get_sequence(req); |
| /* Still a chance to pass the sequence check */ |
| if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) |
| return 0; |
| |
| if (!req->io) { |
| ret = io_req_defer_prep(req, sqe); |
| if (ret) |
| return ret; |
| } |
| io_prep_async_link(req); |
| de = kmalloc(sizeof(*de), GFP_KERNEL); |
| if (!de) |
| return -ENOMEM; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) { |
| spin_unlock_irq(&ctx->completion_lock); |
| kfree(de); |
| io_queue_async_work(req); |
| return -EIOCBQUEUED; |
| } |
| |
| trace_io_uring_defer(ctx, req, req->user_data); |
| de->req = req; |
| de->seq = seq; |
| list_add_tail(&de->list, &ctx->defer_list); |
| spin_unlock_irq(&ctx->completion_lock); |
| return -EIOCBQUEUED; |
| } |
| |
| static void __io_clean_op(struct io_kiocb *req) |
| { |
| struct io_async_ctx *io = req->io; |
| |
| if (req->flags & REQ_F_BUFFER_SELECTED) { |
| switch (req->opcode) { |
| case IORING_OP_READV: |
| case IORING_OP_READ_FIXED: |
| case IORING_OP_READ: |
| kfree((void *)(unsigned long)req->rw.addr); |
| break; |
| case IORING_OP_RECVMSG: |
| case IORING_OP_RECV: |
| kfree(req->sr_msg.kbuf); |
| break; |
| } |
| req->flags &= ~REQ_F_BUFFER_SELECTED; |
| } |
| |
| if (req->flags & REQ_F_NEED_CLEANUP) { |
| switch (req->opcode) { |
| case IORING_OP_READV: |
| case IORING_OP_READ_FIXED: |
| case IORING_OP_READ: |
| case IORING_OP_WRITEV: |
| case IORING_OP_WRITE_FIXED: |
| case IORING_OP_WRITE: |
| if (io->rw.free_iovec) |
| kfree(io->rw.free_iovec); |
| break; |
| case IORING_OP_RECVMSG: |
| case IORING_OP_SENDMSG: |
| if (io->msg.iov != io->msg.fast_iov) |
| kfree(io->msg.iov); |
| break; |
| case IORING_OP_SPLICE: |
| case IORING_OP_TEE: |
| io_put_file(req, req->splice.file_in, |
| (req->splice.flags & SPLICE_F_FD_IN_FIXED)); |
| break; |
| case IORING_OP_OPENAT: |
| case IORING_OP_OPENAT2: |
| if (req->open.filename) |
| putname(req->open.filename); |
| break; |
| } |
| req->flags &= ~REQ_F_NEED_CLEANUP; |
| } |
| |
| if (req->flags & REQ_F_INFLIGHT) { |
| struct io_ring_ctx *ctx = req->ctx; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&ctx->inflight_lock, flags); |
| list_del(&req->inflight_entry); |
| if (waitqueue_active(&ctx->inflight_wait)) |
| wake_up(&ctx->inflight_wait); |
| spin_unlock_irqrestore(&ctx->inflight_lock, flags); |
| req->flags &= ~REQ_F_INFLIGHT; |
| } |
| } |
| |
| static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
| bool force_nonblock, struct io_comp_state *cs) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| int ret; |
| |
| switch (req->opcode) { |
| case IORING_OP_NOP: |
| ret = io_nop(req, cs); |
| break; |
| case IORING_OP_READV: |
| case IORING_OP_READ_FIXED: |
| case IORING_OP_READ: |
| if (sqe) { |
| ret = io_read_prep(req, sqe, force_nonblock); |
| if (ret < 0) |
| break; |
| } |
| ret = io_read(req, force_nonblock, cs); |
| break; |
| case IORING_OP_WRITEV: |
| case IORING_OP_WRITE_FIXED: |
| case IORING_OP_WRITE: |
| if (sqe) { |
| ret = io_write_prep(req, sqe, force_nonblock); |
| if (ret < 0) |
| break; |
| } |
| ret = io_write(req, force_nonblock, cs); |
| break; |
| case IORING_OP_FSYNC: |
| if (sqe) { |
| ret = io_prep_fsync(req, sqe); |
| if (ret < 0) |
| break; |
| } |
| ret = io_fsync(req, force_nonblock); |
| break; |
| case IORING_OP_POLL_ADD: |
| if (sqe) { |
| ret = io_poll_add_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_poll_add(req); |
| break; |
| case IORING_OP_POLL_REMOVE: |
| if (sqe) { |
| ret = io_poll_remove_prep(req, sqe); |
| if (ret < 0) |
| break; |
| } |
| ret = io_poll_remove(req); |
| break; |
| case IORING_OP_SYNC_FILE_RANGE: |
| if (sqe) { |
| ret = io_prep_sfr(req, sqe); |
| if (ret < 0) |
| break; |
| } |
| ret = io_sync_file_range(req, force_nonblock); |
| break; |
| case IORING_OP_SENDMSG: |
| case IORING_OP_SEND: |
| if (sqe) { |
| ret = io_sendmsg_prep(req, sqe); |
| if (ret < 0) |
| break; |
| } |
| if (req->opcode == IORING_OP_SENDMSG) |
| ret = io_sendmsg(req, force_nonblock, cs); |
| else |
| ret = io_send(req, force_nonblock, cs); |
| break; |
| case IORING_OP_RECVMSG: |
| case IORING_OP_RECV: |
| if (sqe) { |
| ret = io_recvmsg_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| if (req->opcode == IORING_OP_RECVMSG) |
| ret = io_recvmsg(req, force_nonblock, cs); |
| else |
| ret = io_recv(req, force_nonblock, cs); |
| break; |
| case IORING_OP_TIMEOUT: |
| if (sqe) { |
| ret = io_timeout_prep(req, sqe, false); |
| if (ret) |
| break; |
| } |
| ret = io_timeout(req); |
| break; |
| case IORING_OP_TIMEOUT_REMOVE: |
| if (sqe) { |
| ret = io_timeout_remove_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_timeout_remove(req); |
| break; |
| case IORING_OP_ACCEPT: |
| if (sqe) { |
| ret = io_accept_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_accept(req, force_nonblock, cs); |
| break; |
| case IORING_OP_CONNECT: |
| if (sqe) { |
| ret = io_connect_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_connect(req, force_nonblock, cs); |
| break; |
| case IORING_OP_ASYNC_CANCEL: |
| if (sqe) { |
| ret = io_async_cancel_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_async_cancel(req); |
| break; |
| case IORING_OP_FALLOCATE: |
| if (sqe) { |
| ret = io_fallocate_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_fallocate(req, force_nonblock); |
| break; |
| case IORING_OP_OPENAT: |
| if (sqe) { |
| ret = io_openat_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_openat(req, force_nonblock); |
| break; |
| case IORING_OP_CLOSE: |
| if (sqe) { |
| ret = io_close_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_close(req, force_nonblock, cs); |
| break; |
| case IORING_OP_FILES_UPDATE: |
| if (sqe) { |
| ret = io_files_update_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_files_update(req, force_nonblock, cs); |
| break; |
| case IORING_OP_STATX: |
| if (sqe) { |
| ret = io_statx_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_statx(req, force_nonblock); |
| break; |
| case IORING_OP_FADVISE: |
| if (sqe) { |
| ret = io_fadvise_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_fadvise(req, force_nonblock); |
| break; |
| case IORING_OP_MADVISE: |
| if (sqe) { |
| ret = io_madvise_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_madvise(req, force_nonblock); |
| break; |
| case IORING_OP_OPENAT2: |
| if (sqe) { |
| ret = io_openat2_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_openat2(req, force_nonblock); |
| break; |
| case IORING_OP_EPOLL_CTL: |
| if (sqe) { |
| ret = io_epoll_ctl_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_epoll_ctl(req, force_nonblock, cs); |
| break; |
| case IORING_OP_SPLICE: |
| if (sqe) { |
| ret = io_splice_prep(req, sqe); |
| if (ret < 0) |
| break; |
| } |
| ret = io_splice(req, force_nonblock); |
| break; |
| case IORING_OP_PROVIDE_BUFFERS: |
| if (sqe) { |
| ret = io_provide_buffers_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_provide_buffers(req, force_nonblock, cs); |
| break; |
| case IORING_OP_REMOVE_BUFFERS: |
| if (sqe) { |
| ret = io_remove_buffers_prep(req, sqe); |
| if (ret) |
| break; |
| } |
| ret = io_remove_buffers(req, force_nonblock, cs); |
| break; |
| case IORING_OP_TEE: |
| if (sqe) { |
| ret = io_tee_prep(req, sqe); |
| if (ret < 0) |
| break; |
| } |
| ret = io_tee(req, force_nonblock); |
| break; |
| default: |
| ret = -EINVAL; |
| break; |
| } |
| |
| if (ret) |
| return ret; |
| |
| /* If the op doesn't have a file, we're not polling for it */ |
| if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) { |
| const bool in_async = io_wq_current_is_worker(); |
| |
| /* workqueue context doesn't hold uring_lock, grab it now */ |
| if (in_async) |
| mutex_lock(&ctx->uring_lock); |
| |
| io_iopoll_req_issued(req); |
| |
| if (in_async) |
| mutex_unlock(&ctx->uring_lock); |
| } |
| |
| return 0; |
| } |
| |
| static struct io_wq_work *io_wq_submit_work(struct io_wq_work *work) |
| { |
| struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
| struct io_kiocb *timeout; |
| int ret = 0; |
| |
| timeout = io_prep_linked_timeout(req); |
| if (timeout) |
| io_queue_linked_timeout(timeout); |
| |
| /* if NO_CANCEL is set, we must still run the work */ |
| if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) == |
| IO_WQ_WORK_CANCEL) { |
| ret = -ECANCELED; |
| } |
| |
| if (!ret) { |
| do { |
| ret = io_issue_sqe(req, NULL, false, NULL); |
| /* |
| * We can get EAGAIN for polled IO even though we're |
| * forcing a sync submission from here, since we can't |
| * wait for request slots on the block side. |
| */ |
| if (ret != -EAGAIN) |
| break; |
| cond_resched(); |
| } while (1); |
| } |
| |
| if (ret) { |
| req_set_fail_links(req); |
| io_req_complete(req, ret); |
| } |
| |
| return io_steal_work(req); |
| } |
| |
| static inline struct file *io_file_from_index(struct io_ring_ctx *ctx, |
| int index) |
| { |
| struct fixed_file_table *table; |
| |
| table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT]; |
| return table->files[index & IORING_FILE_TABLE_MASK]; |
| } |
| |
| static int io_file_get(struct io_submit_state *state, struct io_kiocb *req, |
| int fd, struct file **out_file, bool fixed) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| struct file *file; |
| |
| if (fixed) { |
| if (unlikely(!ctx->file_data || |
| (unsigned) fd >= ctx->nr_user_files)) |
| return -EBADF; |
| fd = array_index_nospec(fd, ctx->nr_user_files); |
| file = io_file_from_index(ctx, fd); |
| if (file) { |
| req->fixed_file_refs = ctx->file_data->cur_refs; |
| percpu_ref_get(req->fixed_file_refs); |
| } |
| } else { |
| trace_io_uring_file_get(ctx, fd); |
| file = __io_file_get(state, fd); |
| } |
| |
| if (file || io_op_defs[req->opcode].needs_file_no_error) { |
| *out_file = file; |
| return 0; |
| } |
| return -EBADF; |
| } |
| |
| static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req, |
| int fd) |
| { |
| bool fixed; |
| |
| fixed = (req->flags & REQ_F_FIXED_FILE) != 0; |
| if (unlikely(!fixed && io_async_submit(req->ctx))) |
| return -EBADF; |
| |
| return io_file_get(state, req, fd, &req->file, fixed); |
| } |
| |
| static int io_grab_files(struct io_kiocb *req) |
| { |
| int ret = -EBADF; |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| io_req_init_async(req); |
| |
| if (req->work.files || (req->flags & REQ_F_NO_FILE_TABLE)) |
| return 0; |
| if (!ctx->ring_file) |
| return -EBADF; |
| |
| rcu_read_lock(); |
| spin_lock_irq(&ctx->inflight_lock); |
| /* |
| * We use the f_ops->flush() handler to ensure that we can flush |
| * out work accessing these files if the fd is closed. Check if |
| * the fd has changed since we started down this path, and disallow |
| * this operation if it has. |
| */ |
| if (fcheck(ctx->ring_fd) == ctx->ring_file) { |
| list_add(&req->inflight_entry, &ctx->inflight_list); |
| req->flags |= REQ_F_INFLIGHT; |
| req->work.files = current->files; |
| ret = 0; |
| } |
| spin_unlock_irq(&ctx->inflight_lock); |
| rcu_read_unlock(); |
| |
| return ret; |
| } |
| |
| static inline int io_prep_work_files(struct io_kiocb *req) |
| { |
| if (!io_op_defs[req->opcode].file_table) |
| return 0; |
| return io_grab_files(req); |
| } |
| |
| static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) |
| { |
| struct io_timeout_data *data = container_of(timer, |
| struct io_timeout_data, timer); |
| struct io_kiocb *req = data->req; |
| struct io_ring_ctx *ctx = req->ctx; |
| struct io_kiocb *prev = NULL; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&ctx->completion_lock, flags); |
| |
| /* |
| * We don't expect the list to be empty, that will only happen if we |
| * race with the completion of the linked work. |
| */ |
| if (!list_empty(&req->link_list)) { |
| prev = list_entry(req->link_list.prev, struct io_kiocb, |
| link_list); |
| if (refcount_inc_not_zero(&prev->refs)) { |
| list_del_init(&req->link_list); |
| prev->flags &= ~REQ_F_LINK_TIMEOUT; |
| } else |
| prev = NULL; |
| } |
| |
| spin_unlock_irqrestore(&ctx->completion_lock, flags); |
| |
| if (prev) { |
| req_set_fail_links(prev); |
| io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME); |
| io_put_req(prev); |
| } else { |
| io_req_complete(req, -ETIME); |
| } |
| return HRTIMER_NORESTART; |
| } |
| |
| static void __io_queue_linked_timeout(struct io_kiocb *req) |
| { |
| /* |
| * If the list is now empty, then our linked request finished before |
| * we got a chance to setup the timer |
| */ |
| if (!list_empty(&req->link_list)) { |
| struct io_timeout_data *data = &req->io->timeout; |
| |
| data->timer.function = io_link_timeout_fn; |
| hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), |
| data->mode); |
| } |
| } |
| |
| static void io_queue_linked_timeout(struct io_kiocb *req) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| __io_queue_linked_timeout(req); |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| /* drop submission reference */ |
| io_put_req(req); |
| } |
| |
| static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) |
| { |
| struct io_kiocb *nxt; |
| |
| if (!(req->flags & REQ_F_LINK_HEAD)) |
| return NULL; |
| if (req->flags & REQ_F_LINK_TIMEOUT) |
| return NULL; |
| |
| nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, |
| link_list); |
| if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT) |
| return NULL; |
| |
| req->flags |= REQ_F_LINK_TIMEOUT; |
| return nxt; |
| } |
| |
| static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
| struct io_comp_state *cs) |
| { |
| struct io_kiocb *linked_timeout; |
| struct io_kiocb *nxt; |
| const struct cred *old_creds = NULL; |
| int ret; |
| |
| again: |
| linked_timeout = io_prep_linked_timeout(req); |
| |
| if ((req->flags & REQ_F_WORK_INITIALIZED) && req->work.creds && |
| req->work.creds != current_cred()) { |
| if (old_creds) |
| revert_creds(old_creds); |
| if (old_creds == req->work.creds) |
| old_creds = NULL; /* restored original creds */ |
| else |
| old_creds = override_creds(req->work.creds); |
| } |
| |
| ret = io_issue_sqe(req, sqe, true, cs); |
| |
| /* |
| * We async punt it if the file wasn't marked NOWAIT, or if the file |
| * doesn't support non-blocking read/write attempts |
| */ |
| if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) { |
| if (!io_arm_poll_handler(req)) { |
| punt: |
| ret = io_prep_work_files(req); |
| if (unlikely(ret)) |
| goto err; |
| /* |
| * Queued up for async execution, worker will release |
| * submit reference when the iocb is actually submitted. |
| */ |
| io_queue_async_work(req); |
| } |
| |
| if (linked_timeout) |
| io_queue_linked_timeout(linked_timeout); |
| goto exit; |
| } |
| |
| if (unlikely(ret)) { |
| err: |
| /* un-prep timeout, so it'll be killed as any other linked */ |
| req->flags &= ~REQ_F_LINK_TIMEOUT; |
| req_set_fail_links(req); |
| io_put_req(req); |
| io_req_complete(req, ret); |
| goto exit; |
| } |
| |
| /* drop submission reference */ |
| nxt = io_put_req_find_next(req); |
| if (linked_timeout) |
| io_queue_linked_timeout(linked_timeout); |
| |
| if (nxt) { |
| req = nxt; |
| |
| if (req->flags & REQ_F_FORCE_ASYNC) |
| goto punt; |
| goto again; |
| } |
| exit: |
| if (old_creds) |
| revert_creds(old_creds); |
| } |
| |
| static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
| struct io_comp_state *cs) |
| { |
| int ret; |
| |
| ret = io_req_defer(req, sqe); |
| if (ret) { |
| if (ret != -EIOCBQUEUED) { |
| fail_req: |
| req_set_fail_links(req); |
| io_put_req(req); |
| io_req_complete(req, ret); |
| } |
| } else if (req->flags & REQ_F_FORCE_ASYNC) { |
| if (!req->io) { |
| ret = io_req_defer_prep(req, sqe); |
| if (unlikely(ret)) |
| goto fail_req; |
| } |
| |
| /* |
| * Never try inline submit of IOSQE_ASYNC is set, go straight |
| * to async execution. |
| */ |
| io_req_init_async(req); |
| req->work.flags |= IO_WQ_WORK_CONCURRENT; |
| io_queue_async_work(req); |
| } else { |
| __io_queue_sqe(req, sqe, cs); |
| } |
| } |
| |
| static inline void io_queue_link_head(struct io_kiocb *req, |
| struct io_comp_state *cs) |
| { |
| if (unlikely(req->flags & REQ_F_FAIL_LINK)) { |
| io_put_req(req); |
| io_req_complete(req, -ECANCELED); |
| } else |
| io_queue_sqe(req, NULL, cs); |
| } |
| |
| static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
| struct io_kiocb **link, struct io_comp_state *cs) |
| { |
| struct io_ring_ctx *ctx = req->ctx; |
| int ret; |
| |
| /* |
| * If we already have a head request, queue this one for async |
| * submittal once the head completes. If we don't have a head but |
| * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be |
| * submitted sync once the chain is complete. If none of those |
| * conditions are true (normal request), then just queue it. |
| */ |
| if (*link) { |
| struct io_kiocb *head = *link; |
| |
| /* |
| * Taking sequential execution of a link, draining both sides |
| * of the link also fullfils IOSQE_IO_DRAIN semantics for all |
| * requests in the link. So, it drains the head and the |
| * next after the link request. The last one is done via |
| * drain_next flag to persist the effect across calls. |
| */ |
| if (req->flags & REQ_F_IO_DRAIN) { |
| head->flags |= REQ_F_IO_DRAIN; |
| ctx->drain_next = 1; |
| } |
| ret = io_req_defer_prep(req, sqe); |
| if (unlikely(ret)) { |
| /* fail even hard links since we don't submit */ |
| head->flags |= REQ_F_FAIL_LINK; |
| return ret; |
| } |
| trace_io_uring_link(ctx, req, head); |
| io_get_req_task(req); |
| list_add_tail(&req->link_list, &head->link_list); |
| |
| /* last request of a link, enqueue the link */ |
| if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) { |
| io_queue_link_head(head, cs); |
| *link = NULL; |
| } |
| } else { |
| if (unlikely(ctx->drain_next)) { |
| req->flags |= REQ_F_IO_DRAIN; |
| ctx->drain_next = 0; |
| } |
| if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) { |
| req->flags |= REQ_F_LINK_HEAD; |
| INIT_LIST_HEAD(&req->link_list); |
| |
| ret = io_req_defer_prep(req, sqe); |
| if (unlikely(ret)) |
| req->flags |= REQ_F_FAIL_LINK; |
| *link = req; |
| } else { |
| io_queue_sqe(req, sqe, cs); |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Batched submission is done, ensure local IO is flushed out. |
| */ |
| static void io_submit_state_end(struct io_submit_state *state) |
| { |
| if (!list_empty(&state->comp.list)) |
| io_submit_flush_completions(&state->comp); |
| blk_finish_plug(&state->plug); |
| io_state_file_put(state); |
| if (state->free_reqs) |
| kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs); |
| } |
| |
| /* |
| * Start submission side cache. |
| */ |
| static void io_submit_state_start(struct io_submit_state *state, |
| struct io_ring_ctx *ctx, unsigned int max_ios) |
| { |
| blk_start_plug(&state->plug); |
| state->comp.nr = 0; |
| INIT_LIST_HEAD(&state->comp.list); |
| state->comp.ctx = ctx; |
| state->free_reqs = 0; |
| state->file = NULL; |
| state->ios_left = max_ios; |
| } |
| |
| static void io_commit_sqring(struct io_ring_ctx *ctx) |
| { |
| struct io_rings *rings = ctx->rings; |
| |
| /* |
| * Ensure any loads from the SQEs are done at this point, |
| * since once we write the new head, the application could |
| * write new data to them. |
| */ |
| smp_store_release(&rings->sq.head, ctx->cached_sq_head); |
| } |
| |
| /* |
| * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory |
| * that is mapped by userspace. This means that care needs to be taken to |
| * ensure that reads are stable, as we cannot rely on userspace always |
| * being a good citizen. If members of the sqe are validated and then later |
| * used, it's important that those reads are done through READ_ONCE() to |
| * prevent a re-load down the line. |
| */ |
| static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) |
| { |
| u32 *sq_array = ctx->sq_array; |
| unsigned head; |
| |
| /* |
| * The cached sq head (or cq tail) serves two purposes: |
| * |
| * 1) allows us to batch the cost of updating the user visible |
| * head updates. |
| * 2) allows the kernel side to track the head on its own, even |
| * though the application is the one updating it. |
| */ |
| head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]); |
| if (likely(head < ctx->sq_entries)) |
| return &ctx->sq_sqes[head]; |
| |
| /* drop invalid entries */ |
| ctx->cached_sq_dropped++; |
| WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped); |
| return NULL; |
| } |
| |
| static inline void io_consume_sqe(struct io_ring_ctx *ctx) |
| { |
| ctx->cached_sq_head++; |
| } |
| |
| #define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \ |
| IOSQE_IO_HARDLINK | IOSQE_ASYNC | \ |
| IOSQE_BUFFER_SELECT) |
| |
| static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, |
| const struct io_uring_sqe *sqe, |
| struct io_submit_state *state) |
| { |
| unsigned int sqe_flags; |
| int id; |
| |
| req->opcode = READ_ONCE(sqe->opcode); |
| req->user_data = READ_ONCE(sqe->user_data); |
| req->io = NULL; |
| req->file = NULL; |
| req->ctx = ctx; |
| req->flags = 0; |
| /* one is dropped after submission, the other at completion */ |
| refcount_set(&req->refs, 2); |
| req->task = current; |
| req->result = 0; |
| |
| if (unlikely(req->opcode >= IORING_OP_LAST)) |
| return -EINVAL; |
| |
| if (unlikely(io_sq_thread_acquire_mm(ctx, req))) |
| return -EFAULT; |
| |
| sqe_flags = READ_ONCE(sqe->flags); |
| /* enforce forwards compatibility on users */ |
| if (unlikely(sqe_flags & ~SQE_VALID_FLAGS)) |
| return -EINVAL; |
| |
| if ((sqe_flags & IOSQE_BUFFER_SELECT) && |
| !io_op_defs[req->opcode].buffer_select) |
| return -EOPNOTSUPP; |
| |
| id = READ_ONCE(sqe->personality); |
| if (id) { |
| io_req_init_async(req); |
| req->work.creds = idr_find(&ctx->personality_idr, id); |
| if (unlikely(!req->work.creds)) |
| return -EINVAL; |
| get_cred(req->work.creds); |
| } |
| |
| /* same numerical values with corresponding REQ_F_*, safe to copy */ |
| req->flags |= sqe_flags; |
| |
| if (!io_op_defs[req->opcode].needs_file) |
| return 0; |
| |
| return io_req_set_file(state, req, READ_ONCE(sqe->fd)); |
| } |
| |
| static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, |
| struct file *ring_file, int ring_fd) |
| { |
| struct io_submit_state state; |
| struct io_kiocb *link = NULL; |
| int i, submitted = 0; |
| |
| /* if we have a backlog and couldn't flush it all, return BUSY */ |
| if (test_bit(0, &ctx->sq_check_overflow)) { |
| if (!list_empty(&ctx->cq_overflow_list) && |
| !io_cqring_overflow_flush(ctx, false)) |
| return -EBUSY; |
| } |
| |
| /* make sure SQ entry isn't read before tail */ |
| nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx)); |
| |
| if (!percpu_ref_tryget_many(&ctx->refs, nr)) |
| return -EAGAIN; |
| |
| io_submit_state_start(&state, ctx, nr); |
| |
| ctx->ring_fd = ring_fd; |
| ctx->ring_file = ring_file; |
| |
| for (i = 0; i < nr; i++) { |
| const struct io_uring_sqe *sqe; |
| struct io_kiocb *req; |
| int err; |
| |
| sqe = io_get_sqe(ctx); |
| if (unlikely(!sqe)) { |
| io_consume_sqe(ctx); |
| break; |
| } |
| req = io_alloc_req(ctx, &state); |
| if (unlikely(!req)) { |
| if (!submitted) |
| submitted = -EAGAIN; |
| break; |
| } |
| |
| err = io_init_req(ctx, req, sqe, &state); |
| io_consume_sqe(ctx); |
| /* will complete beyond this point, count as submitted */ |
| submitted++; |
| |
| if (unlikely(err)) { |
| fail_req: |
| io_put_req(req); |
| io_req_complete(req, err); |
| break; |
| } |
| |
| trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data, |
| true, io_async_submit(ctx)); |
| err = io_submit_sqe(req, sqe, &link, &state.comp); |
| if (err) |
| goto fail_req; |
| } |
| |
| if (unlikely(submitted != nr)) { |
| int ref_used = (submitted == -EAGAIN) ? 0 : submitted; |
| |
| percpu_ref_put_many(&ctx->refs, nr - ref_used); |
| } |
| if (link) |
| io_queue_link_head(link, &state.comp); |
| io_submit_state_end(&state); |
| |
| /* Commit SQ ring head once we've consumed and submitted all SQEs */ |
| io_commit_sqring(ctx); |
| |
| return submitted; |
| } |
| |
| static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx) |
| { |
| /* Tell userspace we may need a wakeup call */ |
| spin_lock_irq(&ctx->completion_lock); |
| ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP; |
| spin_unlock_irq(&ctx->completion_lock); |
| } |
| |
| static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx) |
| { |
| spin_lock_irq(&ctx->completion_lock); |
| ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; |
| spin_unlock_irq(&ctx->completion_lock); |
| } |
| |
| static int io_sq_thread(void *data) |
| { |
| struct io_ring_ctx *ctx = data; |
| const struct cred *old_cred; |
| DEFINE_WAIT(wait); |
| unsigned long timeout; |
| int ret = 0; |
| |
| complete(&ctx->sq_thread_comp); |
| |
| old_cred = override_creds(ctx->creds); |
| |
| timeout = jiffies + ctx->sq_thread_idle; |
| while (!kthread_should_park()) { |
| unsigned int to_submit; |
| |
| if (!list_empty(&ctx->iopoll_list)) { |
| unsigned nr_events = 0; |
| |
| mutex_lock(&ctx->uring_lock); |
| if (!list_empty(&ctx->iopoll_list) && !need_resched()) |
| io_do_iopoll(ctx, &nr_events, 0); |
| else |
| timeout = jiffies + ctx->sq_thread_idle; |
| mutex_unlock(&ctx->uring_lock); |
| } |
| |
| to_submit = io_sqring_entries(ctx); |
| |
| /* |
| * If submit got -EBUSY, flag us as needing the application |
| * to enter the kernel to reap and flush events. |
| */ |
| if (!to_submit || ret == -EBUSY || need_resched()) { |
| /* |
| * Drop cur_mm before scheduling, we can't hold it for |
| * long periods (or over schedule()). Do this before |
| * adding ourselves to the waitqueue, as the unuse/drop |
| * may sleep. |
| */ |
| io_sq_thread_drop_mm(); |
| |
| /* |
| * We're polling. If we're within the defined idle |
| * period, then let us spin without work before going |
| * to sleep. The exception is if we got EBUSY doing |
| * more IO, we should wait for the application to |
| * reap events and wake us up. |
| */ |
| if (!list_empty(&ctx->iopoll_list) || need_resched() || |
| (!time_after(jiffies, timeout) && ret != -EBUSY && |
| !percpu_ref_is_dying(&ctx->refs))) { |
| io_run_task_work(); |
| cond_resched(); |
| continue; |
| } |
| |
| prepare_to_wait(&ctx->sqo_wait, &wait, |
| TASK_INTERRUPTIBLE); |
| |
| /* |
| * While doing polled IO, before going to sleep, we need |
| * to check if there are new reqs added to iopoll_list, |
| * it is because reqs may have been punted to io worker |
| * and will be added to iopoll_list later, hence check |
| * the iopoll_list again. |
| */ |
| if ((ctx->flags & IORING_SETUP_IOPOLL) && |
| !list_empty_careful(&ctx->iopoll_list)) { |
| finish_wait(&ctx->sqo_wait, &wait); |
| continue; |
| } |
| |
| io_ring_set_wakeup_flag(ctx); |
| |
| to_submit = io_sqring_entries(ctx); |
| if (!to_submit || ret == -EBUSY) { |
| if (kthread_should_park()) { |
| finish_wait(&ctx->sqo_wait, &wait); |
| break; |
| } |
| if (io_run_task_work()) { |
| finish_wait(&ctx->sqo_wait, &wait); |
| io_ring_clear_wakeup_flag(ctx); |
| continue; |
| } |
| if (signal_pending(current)) |
| flush_signals(current); |
| schedule(); |
| finish_wait(&ctx->sqo_wait, &wait); |
| |
| io_ring_clear_wakeup_flag(ctx); |
| ret = 0; |
| continue; |
| } |
| finish_wait(&ctx->sqo_wait, &wait); |
| |
| io_ring_clear_wakeup_flag(ctx); |
| } |
| |
| mutex_lock(&ctx->uring_lock); |
| if (likely(!percpu_ref_is_dying(&ctx->refs))) |
| ret = io_submit_sqes(ctx, to_submit, NULL, -1); |
| mutex_unlock(&ctx->uring_lock); |
| timeout = jiffies + ctx->sq_thread_idle; |
| } |
| |
| io_run_task_work(); |
| |
| io_sq_thread_drop_mm(); |
| revert_creds(old_cred); |
| |
| kthread_parkme(); |
| |
| return 0; |
| } |
| |
| struct io_wait_queue { |
| struct wait_queue_entry wq; |
| struct io_ring_ctx *ctx; |
| unsigned to_wait; |
| unsigned nr_timeouts; |
| }; |
| |
| static inline bool io_should_wake(struct io_wait_queue *iowq, bool noflush) |
| { |
| struct io_ring_ctx *ctx = iowq->ctx; |
| |
| /* |
| * Wake up if we have enough events, or if a timeout occurred since we |
| * started waiting. For timeouts, we always want to return to userspace, |
| * regardless of event count. |
| */ |
| return io_cqring_events(ctx, noflush) >= iowq->to_wait || |
| atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; |
| } |
| |
| static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode, |
| int wake_flags, void *key) |
| { |
| struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, |
| wq); |
| |
| /* use noflush == true, as we can't safely rely on locking context */ |
| if (!io_should_wake(iowq, true)) |
| return -1; |
| |
| return autoremove_wake_function(curr, mode, wake_flags, key); |
| } |
| |
| /* |
| * Wait until events become available, if we don't already have some. The |
| * application must reap them itself, as they reside on the shared cq ring. |
| */ |
| static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, |
| const sigset_t __user *sig, size_t sigsz) |
| { |
| struct io_wait_queue iowq = { |
| .wq = { |
| .private = current, |
| .func = io_wake_function, |
| .entry = LIST_HEAD_INIT(iowq.wq.entry), |
| }, |
| .ctx = ctx, |
| .to_wait = min_events, |
| }; |
| struct io_rings *rings = ctx->rings; |
| int ret = 0; |
| |
| do { |
| if (io_cqring_events(ctx, false) >= min_events) |
| return 0; |
| if (!io_run_task_work()) |
| break; |
| } while (1); |
| |
| if (sig) { |
| #ifdef CONFIG_COMPAT |
| if (in_compat_syscall()) |
| ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig, |
| sigsz); |
| else |
| #endif |
| ret = set_user_sigmask(sig, sigsz); |
| |
| if (ret) |
| return ret; |
| } |
| |
| iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts); |
| trace_io_uring_cqring_wait(ctx, min_events); |
| do { |
| prepare_to_wait_exclusive(&ctx->wait, &iowq.wq, |
| TASK_INTERRUPTIBLE); |
| /* make sure we run task_work before checking for signals */ |
| if (io_run_task_work()) |
| continue; |
| if (signal_pending(current)) { |
| if (current->jobctl & JOBCTL_TASK_WORK) { |
| spin_lock_irq(¤t->sighand->siglock); |
| current->jobctl &= ~JOBCTL_TASK_WORK; |
| recalc_sigpending(); |
| spin_unlock_irq(¤t->sighand->siglock); |
| continue; |
| } |
| ret = -EINTR; |
| break; |
| } |
| if (io_should_wake(&iowq, false)) |
| break; |
| schedule(); |
| } while (1); |
| finish_wait(&ctx->wait, &iowq.wq); |
| |
| restore_saved_sigmask_unless(ret == -EINTR); |
| |
| return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; |
| } |
| |
| static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) |
| { |
| #if defined(CONFIG_UNIX) |
| if (ctx->ring_sock) { |
| struct sock *sock = ctx->ring_sock->sk; |
| struct sk_buff *skb; |
| |
| while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL) |
| kfree_skb(skb); |
| } |
| #else |
| int i; |
| |
| for (i = 0; i < ctx->nr_user_files; i++) { |
| struct file *file; |
| |
| file = io_file_from_index(ctx, i); |
| if (file) |
| fput(file); |
| } |
| #endif |
| } |
| |
| static void io_file_ref_kill(struct percpu_ref *ref) |
| { |
| struct fixed_file_data *data; |
| |
| data = container_of(ref, struct fixed_file_data, refs); |
| complete(&data->done); |
| } |
| |
| static int io_sqe_files_unregister(struct io_ring_ctx *ctx) |
| { |
| struct fixed_file_data *data = ctx->file_data; |
| struct fixed_file_ref_node *ref_node = NULL; |
| unsigned nr_tables, i; |
| |
| if (!data) |
| return -ENXIO; |
| |
| spin_lock(&data->lock); |
| if (!list_empty(&data->ref_list)) |
| ref_node = list_first_entry(&data->ref_list, |
| struct fixed_file_ref_node, node); |
| spin_unlock(&data->lock); |
| if (ref_node) |
| percpu_ref_kill(&ref_node->refs); |
| |
| percpu_ref_kill(&data->refs); |
| |
| /* wait for all refs nodes to complete */ |
| flush_delayed_work(&ctx->file_put_work); |
| wait_for_completion(&data->done); |
| |
| __io_sqe_files_unregister(ctx); |
| nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE); |
| for (i = 0; i < nr_tables; i++) |
| kfree(data->table[i].files); |
| kfree(data->table); |
| percpu_ref_exit(&data->refs); |
| kfree(data); |
| ctx->file_data = NULL; |
| ctx->nr_user_files = 0; |
| return 0; |
| } |
| |
| static void io_sq_thread_stop(struct io_ring_ctx *ctx) |
| { |
| if (ctx->sqo_thread) { |
| wait_for_completion(&ctx->sq_thread_comp); |
| /* |
| * The park is a bit of a work-around, without it we get |
| * warning spews on shutdown with SQPOLL set and affinity |
| * set to a single CPU. |
| */ |
| kthread_park(ctx->sqo_thread); |
| kthread_stop(ctx->sqo_thread); |
| ctx->sqo_thread = NULL; |
| } |
| } |
| |
| static void io_finish_async(struct io_ring_ctx *ctx) |
| { |
| io_sq_thread_stop(ctx); |
| |
| if (ctx->io_wq) { |
| io_wq_destroy(ctx->io_wq); |
| ctx->io_wq = NULL; |
| } |
| } |
| |
| #if defined(CONFIG_UNIX) |
| /* |
| * Ensure the UNIX gc is aware of our file set, so we are certain that |
| * the io_uring can be safely unregistered on process exit, even if we have |
| * loops in the file referencing. |
| */ |
| static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) |
| { |
| struct sock *sk = ctx->ring_sock->sk; |
| struct scm_fp_list *fpl; |
| struct sk_buff *skb; |
| int i, nr_files; |
| |
| fpl = kzalloc(sizeof(*fpl), GFP_KERNEL); |
| if (!fpl) |
| return -ENOMEM; |
| |
| skb = alloc_skb(0, GFP_KERNEL); |
| if (!skb) { |
| kfree(fpl); |
| return -ENOMEM; |
| } |
| |
| skb->sk = sk; |
| |
| nr_files = 0; |
| fpl->user = get_uid(ctx->user); |
| for (i = 0; i < nr; i++) { |
| struct file *file = io_file_from_index(ctx, i + offset); |
| |
| if (!file) |
| continue; |
| fpl->fp[nr_files] = get_file(file); |
| unix_inflight(fpl->user, fpl->fp[nr_files]); |
| nr_files++; |
| } |
| |
| if (nr_files) { |
| fpl->max = SCM_MAX_FD; |
| fpl->count = nr_files; |
| UNIXCB(skb).fp = fpl; |
| skb->destructor = unix_destruct_scm; |
| refcount_add(skb->truesize, &sk->sk_wmem_alloc); |
| skb_queue_head(&sk->sk_receive_queue, skb); |
| |
| for (i = 0; i < nr_files; i++) |
| fput(fpl->fp[i]); |
| } else { |
| kfree_skb(skb); |
| kfree(fpl); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * If UNIX sockets are enabled, fd passing can cause a reference cycle which |
| * causes regular reference counting to break down. We rely on the UNIX |
| * garbage collection to take care of this problem for us. |
| */ |
| static int io_sqe_files_scm(struct io_ring_ctx *ctx) |
| { |
| unsigned left, total; |
| int ret = 0; |
| |
| total = 0; |
| left = ctx->nr_user_files; |
| while (left) { |
| unsigned this_files = min_t(unsigned, left, SCM_MAX_FD); |
| |
| ret = __io_sqe_files_scm(ctx, this_files, total); |
| if (ret) |
| break; |
| left -= this_files; |
| total += this_files; |
| } |
| |
| if (!ret) |
| return 0; |
| |
| while (total < ctx->nr_user_files) { |
| struct file *file = io_file_from_index(ctx, total); |
| |
| if (file) |
| fput(file); |
| total++; |
| } |
| |
| return ret; |
| } |
| #else |
| static int io_sqe_files_scm(struct io_ring_ctx *ctx) |
| { |
| return 0; |
| } |
| #endif |
| |
| static int io_sqe_alloc_file_tables(struct io_ring_ctx *ctx, unsigned nr_tables, |
| unsigned nr_files) |
| { |
| int i; |
| |
| for (i = 0; i < nr_tables; i++) { |
| struct fixed_file_table *table = &ctx->file_data->table[i]; |
| unsigned this_files; |
| |
| this_files = min(nr_files, IORING_MAX_FILES_TABLE); |
| table->files = kcalloc(this_files, sizeof(struct file *), |
| GFP_KERNEL); |
| if (!table->files) |
| break; |
| nr_files -= this_files; |
| } |
| |
| if (i == nr_tables) |
| return 0; |
| |
| for (i = 0; i < nr_tables; i++) { |
| struct fixed_file_table *table = &ctx->file_data->table[i]; |
| kfree(table->files); |
| } |
| return 1; |
| } |
| |
| static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file) |
| { |
| #if defined(CONFIG_UNIX) |
| struct sock *sock = ctx->ring_sock->sk; |
| struct sk_buff_head list, *head = &sock->sk_receive_queue; |
| struct sk_buff *skb; |
| int i; |
| |
| __skb_queue_head_init(&list); |
| |
| /* |
| * Find the skb that holds this file in its SCM_RIGHTS. When found, |
| * remove this entry and rearrange the file array. |
| */ |
| skb = skb_dequeue(head); |
| while (skb) { |
| struct scm_fp_list *fp; |
| |
| fp = UNIXCB(skb).fp; |
| for (i = 0; i < fp->count; i++) { |
| int left; |
| |
| if (fp->fp[i] != file) |
| continue; |
| |
| unix_notinflight(fp->user, fp->fp[i]); |
| left = fp->count - 1 - i; |
| if (left) { |
| memmove(&fp->fp[i], &fp->fp[i + 1], |
| left * sizeof(struct file *)); |
| } |
| fp->count--; |
| if (!fp->count) { |
| kfree_skb(skb); |
| skb = NULL; |
| } else { |
| __skb_queue_tail(&list, skb); |
| } |
| fput(file); |
| file = NULL; |
| break; |
| } |
| |
| if (!file) |
| break; |
| |
| __skb_queue_tail(&list, skb); |
| |
| skb = skb_dequeue(head); |
| } |
| |
| if (skb_peek(&list)) { |
| spin_lock_irq(&head->lock); |
| while ((skb = __skb_dequeue(&list)) != NULL) |
| __skb_queue_tail(head, skb); |
| spin_unlock_irq(&head->lock); |
| } |
| #else |
| fput(file); |
| #endif |
| } |
| |
| struct io_file_put { |
| struct list_head list; |
| struct file *file; |
| }; |
| |
| static void __io_file_put_work(struct fixed_file_ref_node *ref_node) |
| { |
| struct fixed_file_data *file_data = ref_node->file_data; |
| struct io_ring_ctx *ctx = file_data->ctx; |
| struct io_file_put *pfile, *tmp; |
| |
| list_for_each_entry_safe(pfile, tmp, &ref_node->file_list, list) { |
| list_del(&pfile->list); |
| io_ring_file_put(ctx, pfile->file); |
| kfree(pfile); |
| } |
| |
| spin_lock(&file_data->lock); |
| list_del(&ref_node->node); |
| spin_unlock(&file_data->lock); |
| |
| percpu_ref_exit(&ref_node->refs); |
| kfree(ref_node); |
| percpu_ref_put(&file_data->refs); |
| } |
| |
| static void io_file_put_work(struct work_struct *work) |
| { |
| struct io_ring_ctx *ctx; |
| struct llist_node *node; |
| |
| ctx = container_of(work, struct io_ring_ctx, file_put_work.work); |
| node = llist_del_all(&ctx->file_put_llist); |
| |
| while (node) { |
| struct fixed_file_ref_node *ref_node; |
| struct llist_node *next = node->next; |
| |
| ref_node = llist_entry(node, struct fixed_file_ref_node, llist); |
| __io_file_put_work(ref_node); |
| node = next; |
| } |
| } |
| |
| static void io_file_data_ref_zero(struct percpu_ref *ref) |
| { |
| struct fixed_file_ref_node *ref_node; |
| struct io_ring_ctx *ctx; |
| bool first_add; |
| int delay = HZ; |
| |
| ref_node = container_of(ref, struct fixed_file_ref_node, refs); |
| ctx = ref_node->file_data->ctx; |
| |
| if (percpu_ref_is_dying(&ctx->file_data->refs)) |
| delay = 0; |
| |
| first_add = llist_add(&ref_node->llist, &ctx->file_put_llist); |
| if (!delay) |
| mod_delayed_work(system_wq, &ctx->file_put_work, 0); |
| else if (first_add) |
| queue_delayed_work(system_wq, &ctx->file_put_work, delay); |
| } |
| |
| static struct fixed_file_ref_node *alloc_fixed_file_ref_node( |
| struct io_ring_ctx *ctx) |
| { |
| struct fixed_file_ref_node *ref_node; |
| |
| ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL); |
| if (!ref_node) |
| return ERR_PTR(-ENOMEM); |
| |
| if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero, |
| 0, GFP_KERNEL)) { |
| kfree(ref_node); |
| return ERR_PTR(-ENOMEM); |
| } |
| INIT_LIST_HEAD(&ref_node->node); |
| INIT_LIST_HEAD(&ref_node->file_list); |
| ref_node->file_data = ctx->file_data; |
| return ref_node; |
| } |
| |
| static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node) |
| { |
| percpu_ref_exit(&ref_node->refs); |
| kfree(ref_node); |
| } |
| |
| static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, |
| unsigned nr_args) |
| { |
| __s32 __user *fds = (__s32 __user *) arg; |
| unsigned nr_tables; |
| struct file *file; |
| int fd, ret = 0; |
| unsigned i; |
| struct fixed_file_ref_node *ref_node; |
| |
| if (ctx->file_data) |
| return -EBUSY; |
| if (!nr_args) |
| return -EINVAL; |
| if (nr_args > IORING_MAX_FIXED_FILES) |
| return -EMFILE; |
| |
| ctx->file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL); |
| if (!ctx->file_data) |
| return -ENOMEM; |
| ctx->file_data->ctx = ctx; |
| init_completion(&ctx->file_data->done); |
| INIT_LIST_HEAD(&ctx->file_data->ref_list); |
| spin_lock_init(&ctx->file_data->lock); |
| |
| nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE); |
| ctx->file_data->table = kcalloc(nr_tables, |
| sizeof(struct fixed_file_table), |
| GFP_KERNEL); |
| if (!ctx->file_data->table) { |
| kfree(ctx->file_data); |
| ctx->file_data = NULL; |
| return -ENOMEM; |
| } |
| |
| if (percpu_ref_init(&ctx->file_data->refs, io_file_ref_kill, |
| PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) { |
| kfree(ctx->file_data->table); |
| kfree(ctx->file_data); |
| ctx->file_data = NULL; |
| return -ENOMEM; |
| } |
| |
| if (io_sqe_alloc_file_tables(ctx, nr_tables, nr_args)) { |
| percpu_ref_exit(&ctx->file_data->refs); |
| kfree(ctx->file_data->table); |
| kfree(ctx->file_data); |
| ctx->file_data = NULL; |
| return -ENOMEM; |
| } |
| |
| for (i = 0; i < nr_args; i++, ctx->nr_user_files++) { |
| struct fixed_file_table *table; |
| unsigned index; |
| |
| ret = -EFAULT; |
| if (copy_from_user(&fd, &fds[i], sizeof(fd))) |
| break; |
| /* allow sparse sets */ |
| if (fd == -1) { |
| ret = 0; |
| continue; |
| } |
| |
| table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT]; |
| index = i & IORING_FILE_TABLE_MASK; |
| file = fget(fd); |
| |
| ret = -EBADF; |
| if (!file) |
| break; |
| |
| /* |
| * Don't allow io_uring instances to be registered. If UNIX |
| * isn't enabled, then this causes a reference cycle and this |
| * instance can never get freed. If UNIX is enabled we'll |
| * handle it just fine, but there's still no point in allowing |
| * a ring fd as it doesn't support regular read/write anyway. |
| */ |
| if (file->f_op == &io_uring_fops) { |
| fput(file); |
| break; |
| } |
| ret = 0; |
| table->files[index] = file; |
| } |
| |
| if (ret) { |
| for (i = 0; i < ctx->nr_user_files; i++) { |
| file = io_file_from_index(ctx, i); |
| if (file) |
| fput(file); |
| } |
| for (i = 0; i < nr_tables; i++) |
| kfree(ctx->file_data->table[i].files); |
| |
| percpu_ref_exit(&ctx->file_data->refs); |
| kfree(ctx->file_data->table); |
| kfree(ctx->file_data); |
| ctx->file_data = NULL; |
| ctx->nr_user_files = 0; |
| return ret; |
| } |
| |
| ret = io_sqe_files_scm(ctx); |
| if (ret) { |
| io_sqe_files_unregister(ctx); |
| return ret; |
| } |
| |
| ref_node = alloc_fixed_file_ref_node(ctx); |
| if (IS_ERR(ref_node)) { |
| io_sqe_files_unregister(ctx); |
| return PTR_ERR(ref_node); |
| } |
| |
| ctx->file_data->cur_refs = &ref_node->refs; |
| spin_lock(&ctx->file_data->lock); |
| list_add(&ref_node->node, &ctx->file_data->ref_list); |
| spin_unlock(&ctx->file_data->lock); |
| percpu_ref_get(&ctx->file_data->refs); |
| return ret; |
| } |
| |
| static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file, |
| int index) |
| { |
| #if defined(CONFIG_UNIX) |
| struct sock *sock = ctx->ring_sock->sk; |
| struct sk_buff_head *head = &sock->sk_receive_queue; |
| struct sk_buff *skb; |
| |
| /* |
| * See if we can merge this file into an existing skb SCM_RIGHTS |
| * file set. If there's no room, fall back to allocating a new skb |
| * and filling it in. |
| */ |
| spin_lock_irq(&head->lock); |
| skb = skb_peek(head); |
| if (skb) { |
| struct scm_fp_list *fpl = UNIXCB(skb).fp; |
| |
| if (fpl->count < SCM_MAX_FD) { |
| __skb_unlink(skb, head); |
| spin_unlock_irq(&head->lock); |
| fpl->fp[fpl->count] = get_file(file); |
| unix_inflight(fpl->user, fpl->fp[fpl->count]); |
| fpl->count++; |
| spin_lock_irq(&head->lock); |
| __skb_queue_head(head, skb); |
| } else { |
| skb = NULL; |
| } |
| } |
| spin_unlock_irq(&head->lock); |
| |
| if (skb) { |
| fput(file); |
| return 0; |
| } |
| |
| return __io_sqe_files_scm(ctx, 1, index); |
| #else |
| return 0; |
| #endif |
| } |
| |
| static int io_queue_file_removal(struct fixed_file_data *data, |
| struct file *file) |
| { |
| struct io_file_put *pfile; |
| struct percpu_ref *refs = data->cur_refs; |
| struct fixed_file_ref_node *ref_node; |
| |
| pfile = kzalloc(sizeof(*pfile), GFP_KERNEL); |
| if (!pfile) |
| return -ENOMEM; |
| |
| ref_node = container_of(refs, struct fixed_file_ref_node, refs); |
| pfile->file = file; |
| list_add(&pfile->list, &ref_node->file_list); |
| |
| return 0; |
| } |
| |
| static int __io_sqe_files_update(struct io_ring_ctx *ctx, |
| struct io_uring_files_update *up, |
| unsigned nr_args) |
| { |
| struct fixed_file_data *data = ctx->file_data; |
| struct fixed_file_ref_node *ref_node; |
| struct file *file; |
| __s32 __user *fds; |
| int fd, i, err; |
| __u32 done; |
| bool needs_switch = false; |
| |
| if (check_add_overflow(up->offset, nr_args, &done)) |
| return -EOVERFLOW; |
| if (done > ctx->nr_user_files) |
| return -EINVAL; |
| |
| ref_node = alloc_fixed_file_ref_node(ctx); |
| if (IS_ERR(ref_node)) |
| return PTR_ERR(ref_node); |
| |
| done = 0; |
| fds = u64_to_user_ptr(up->fds); |
| while (nr_args) { |
| struct fixed_file_table *table; |
| unsigned index; |
| |
| err = 0; |
| if (copy_from_user(&fd, &fds[done], sizeof(fd))) { |
| err = -EFAULT; |
| break; |
| } |
| i = array_index_nospec(up->offset, ctx->nr_user_files); |
| table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT]; |
| index = i & IORING_FILE_TABLE_MASK; |
| if (table->files[index]) { |
| file = table->files[index]; |
| err = io_queue_file_removal(data, file); |
| if (err) |
| break; |
| table->files[index] = NULL; |
| needs_switch = true; |
| } |
| if (fd != -1) { |
| file = fget(fd); |
| if (!file) { |
| err = -EBADF; |
| break; |
| } |
| /* |
| * Don't allow io_uring instances to be registered. If |
| * UNIX isn't enabled, then this causes a reference |
| * cycle and this instance can never get freed. If UNIX |
| * is enabled we'll handle it just fine, but there's |
| * still no point in allowing a ring fd as it doesn't |
| * support regular read/write anyway. |
| */ |
| if (file->f_op == &io_uring_fops) { |
| fput(file); |
| err = -EBADF; |
| break; |
| } |
| table->files[index] = file; |
| err = io_sqe_file_register(ctx, file, i); |
| if (err) { |
| table->files[index] = NULL; |
| fput(file); |
| break; |
| } |
| } |
| nr_args--; |
| done++; |
| up->offset++; |
| } |
| |
| if (needs_switch) { |
| percpu_ref_kill(data->cur_refs); |
| spin_lock(&data->lock); |
| list_add(&ref_node->node, &data->ref_list); |
| data->cur_refs = &ref_node->refs; |
| spin_unlock(&data->lock); |
| percpu_ref_get(&ctx->file_data->refs); |
| } else |
| destroy_fixed_file_ref_node(ref_node); |
| |
| return done ? done : err; |
| } |
| |
| static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg, |
| unsigned nr_args) |
| { |
| struct io_uring_files_update up; |
| |
| if (!ctx->file_data) |
| return -ENXIO; |
| if (!nr_args) |
| return -EINVAL; |
| if (copy_from_user(&up, arg, sizeof(up))) |
| return -EFAULT; |
| if (up.resv) |
| return -EINVAL; |
| |
| return __io_sqe_files_update(ctx, &up, nr_args); |
| } |
| |
| static void io_free_work(struct io_wq_work *work) |
| { |
| struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
| |
| /* Consider that io_steal_work() relies on this ref */ |
| io_put_req(req); |
| } |
| |
| static int io_init_wq_offload(struct io_ring_ctx *ctx, |
| struct io_uring_params *p) |
| { |
| struct io_wq_data data; |
| struct fd f; |
| struct io_ring_ctx *ctx_attach; |
| unsigned int concurrency; |
| int ret = 0; |
| |
| data.user = ctx->user; |
| data.free_work = io_free_work; |
| data.do_work = io_wq_submit_work; |
| |
| if (!(p->flags & IORING_SETUP_ATTACH_WQ)) { |
| /* Do QD, or 4 * CPUS, whatever is smallest */ |
| concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); |
| |
| ctx->io_wq = io_wq_create(concurrency, &data); |
| if (IS_ERR(ctx->io_wq)) { |
| ret = PTR_ERR(ctx->io_wq); |
| ctx->io_wq = NULL; |
| } |
| return ret; |
| } |
| |
| f = fdget(p->wq_fd); |
| if (!f.file) |
| return -EBADF; |
| |
| if (f.file->f_op != &io_uring_fops) { |
| ret = -EINVAL; |
| goto out_fput; |
| } |
| |
| ctx_attach = f.file->private_data; |
| /* @io_wq is protected by holding the fd */ |
| if (!io_wq_get(ctx_attach->io_wq, &data)) { |
| ret = -EINVAL; |
| goto out_fput; |
| } |
| |
| ctx->io_wq = ctx_attach->io_wq; |
| out_fput: |
| fdput(f); |
| return ret; |
| } |
| |
| static int io_sq_offload_start(struct io_ring_ctx *ctx, |
| struct io_uring_params *p) |
| { |
| int ret; |
| |
| if (ctx->flags & IORING_SETUP_SQPOLL) { |
| ret = -EPERM; |
| if (!capable(CAP_SYS_ADMIN)) |
| goto err; |
| |
| ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle); |
| if (!ctx->sq_thread_idle) |
| ctx->sq_thread_idle = HZ; |
| |
| if (p->flags & IORING_SETUP_SQ_AFF) { |
| int cpu = p->sq_thread_cpu; |
| |
| ret = -EINVAL; |
| if (cpu >= nr_cpu_ids) |
| goto err; |
| if (!cpu_online(cpu)) |
| goto err; |
| |
| ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread, |
| ctx, cpu, |
| "io_uring-sq"); |
| } else { |
| ctx->sqo_thread = kthread_create(io_sq_thread, ctx, |
| "io_uring-sq"); |
| } |
| if (IS_ERR(ctx->sqo_thread)) { |
| ret = PTR_ERR(ctx->sqo_thread); |
| ctx->sqo_thread = NULL; |
| goto err; |
| } |
| wake_up_process(ctx->sqo_thread); |
| } else if (p->flags & IORING_SETUP_SQ_AFF) { |
| /* Can't have SQ_AFF without SQPOLL */ |
| ret = -EINVAL; |
| goto err; |
| } |
| |
| ret = io_init_wq_offload(ctx, p); |
| if (ret) |
| goto err; |
| |
| return 0; |
| err: |
| io_finish_async(ctx); |
| return ret; |
| } |
| |
| static inline void __io_unaccount_mem(struct user_struct *user, |
| unsigned long nr_pages) |
| { |
| atomic_long_sub(nr_pages, &user->locked_vm); |
| } |
| |
| static inline int __io_account_mem(struct user_struct *user, |
| unsigned long nr_pages) |
| { |
| unsigned long page_limit, cur_pages, new_pages; |
| |
| /* Don't allow more pages than we can safely lock */ |
| page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; |
| |
| do { |
| cur_pages = atomic_long_read(&user->locked_vm); |
| new_pages = cur_pages + nr_pages; |
| if (new_pages > page_limit) |
| return -ENOMEM; |
| } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages, |
| new_pages) != cur_pages); |
| |
| return 0; |
| } |
| |
| static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages, |
| enum io_mem_account acct) |
| { |
| if (ctx->limit_mem) |
| __io_unaccount_mem(ctx->user, nr_pages); |
| |
| if (ctx->sqo_mm) { |
| if (acct == ACCT_LOCKED) |
| ctx->sqo_mm->locked_vm -= nr_pages; |
| else if (acct == ACCT_PINNED) |
| atomic64_sub(nr_pages, &ctx->sqo_mm->pinned_vm); |
| } |
| } |
| |
| static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages, |
| enum io_mem_account acct) |
| { |
| int ret; |
| |
| if (ctx->limit_mem) { |
| ret = __io_account_mem(ctx->user, nr_pages); |
| if (ret) |
| return ret; |
| } |
| |
| if (ctx->sqo_mm) { |
| if (acct == ACCT_LOCKED) |
| ctx->sqo_mm->locked_vm += nr_pages; |
| else if (acct == ACCT_PINNED) |
| atomic64_add(nr_pages, &ctx->sqo_mm->pinned_vm); |
| } |
| |
| return 0; |
| } |
| |
| static void io_mem_free(void *ptr) |
| { |
| struct page *page; |
| |
| if (!ptr) |
| return; |
| |
| page = virt_to_head_page(ptr); |
| if (put_page_testzero(page)) |
| free_compound_page(page); |
| } |
| |
| static void *io_mem_alloc(size_t size) |
| { |
| gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP | |
| __GFP_NORETRY; |
| |
| return (void *) __get_free_pages(gfp_flags, get_order(size)); |
| } |
| |
| static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries, |
| size_t *sq_offset) |
| { |
| struct io_rings *rings; |
| size_t off, sq_array_size; |
| |
| off = struct_size(rings, cqes, cq_entries); |
| if (off == SIZE_MAX) |
| return SIZE_MAX; |
| |
| #ifdef CONFIG_SMP |
| off = ALIGN(off, SMP_CACHE_BYTES); |
| if (off == 0) |
| return SIZE_MAX; |
| #endif |
| |
| if (sq_offset) |
| *sq_offset = off; |
| |
| sq_array_size = array_size(sizeof(u32), sq_entries); |
| if (sq_array_size == SIZE_MAX) |
| return SIZE_MAX; |
| |
| if (check_add_overflow(off, sq_array_size, &off)) |
| return SIZE_MAX; |
| |
| return off; |
| } |
| |
| static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries) |
| { |
| size_t pages; |
| |
| pages = (size_t)1 << get_order( |
| rings_size(sq_entries, cq_entries, NULL)); |
| pages += (size_t)1 << get_order( |
| array_size(sizeof(struct io_uring_sqe), sq_entries)); |
| |
| return pages; |
| } |
| |
| static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx) |
| { |
| int i, j; |
| |
| if (!ctx->user_bufs) |
| return -ENXIO; |
| |
| for (i = 0; i < ctx->nr_user_bufs; i++) { |
| struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; |
| |
| for (j = 0; j < imu->nr_bvecs; j++) |
| unpin_user_page(imu->bvec[j].bv_page); |
| |
| io_unaccount_mem(ctx, imu->nr_bvecs, ACCT_PINNED); |
| kvfree(imu->bvec); |
| imu->nr_bvecs = 0; |
| } |
| |
| kfree(ctx->user_bufs); |
| ctx->user_bufs = NULL; |
| ctx->nr_user_bufs = 0; |
| return 0; |
| } |
| |
| static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, |
| void __user *arg, unsigned index) |
| { |
| struct iovec __user *src; |
| |
| #ifdef CONFIG_COMPAT |
| if (ctx->compat) { |
| struct compat_iovec __user *ciovs; |
| struct compat_iovec ciov; |
| |
| ciovs = (struct compat_iovec __user *) arg; |
| if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov))) |
| return -EFAULT; |
| |
| dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base); |
| dst->iov_len = ciov.iov_len; |
| return 0; |
| } |
| #endif |
| src = (struct iovec __user *) arg; |
| if (copy_from_user(dst, &src[index], sizeof(*dst))) |
| return -EFAULT; |
| return 0; |
| } |
| |
| static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, |
| unsigned nr_args) |
| { |
| struct vm_area_struct **vmas = NULL; |
| struct page **pages = NULL; |
| int i, j, got_pages = 0; |
| int ret = -EINVAL; |
| |
| if (ctx->user_bufs) |
| return -EBUSY; |
| if (!nr_args || nr_args > UIO_MAXIOV) |
| return -EINVAL; |
| |
| ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf), |
| GFP_KERNEL); |
| if (!ctx->user_bufs) |
| return -ENOMEM; |
| |
| for (i = 0; i < nr_args; i++) { |
| struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; |
| unsigned long off, start, end, ubuf; |
| int pret, nr_pages; |
| struct iovec iov; |
| size_t size; |
| |
| ret = io_copy_iov(ctx, &iov, arg, i); |
| if (ret) |
| goto err; |
| |
| /* |
| * Don't impose further limits on the size and buffer |
| * constraints here, we'll -EINVAL later when IO is |
| * submitted if they are wrong. |
| */ |
| ret = -EFAULT; |
| if (!iov.iov_base || !iov.iov_len) |
| goto err; |
| |
| /* arbitrary limit, but we need something */ |
| if (iov.iov_len > SZ_1G) |
| goto err; |
| |
| ubuf = (unsigned long) iov.iov_base; |
| end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| start = ubuf >> PAGE_SHIFT; |
| nr_pages = end - start; |
| |
| ret = io_account_mem(ctx, nr_pages, ACCT_PINNED); |
| if (ret) |
| goto err; |
| |
| ret = 0; |
| if (!pages || nr_pages > got_pages) { |
| kvfree(vmas); |
| kvfree(pages); |
| pages = kvmalloc_array(nr_pages, sizeof(struct page *), |
| GFP_KERNEL); |
| vmas = kvmalloc_array(nr_pages, |
| sizeof(struct vm_area_struct *), |
| GFP_KERNEL); |
| if (!pages || !vmas) { |
| ret = -ENOMEM; |
| io_unaccount_mem(ctx, nr_pages, ACCT_PINNED); |
| goto err; |
| } |
| got_pages = nr_pages; |
| } |
| |
| imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec), |
| GFP_KERNEL); |
| ret = -ENOMEM; |
| if (!imu->bvec) { |
| io_unaccount_mem(ctx, nr_pages, ACCT_PINNED); |
| goto err; |
| } |
| |
| ret = 0; |
| mmap_read_lock(current->mm); |
| pret = pin_user_pages(ubuf, nr_pages, |
| FOLL_WRITE | FOLL_LONGTERM, |
| pages, vmas); |
| if (pret == nr_pages) { |
| /* don't support file backed memory */ |
| for (j = 0; j < nr_pages; j++) { |
| struct vm_area_struct *vma = vmas[j]; |
| |
| if (vma->vm_file && |
| !is_file_hugepages(vma->vm_file)) { |
| ret = -EOPNOTSUPP; |
| break; |
| } |
| } |
| } else { |
| ret = pret < 0 ? pret : -EFAULT; |
| } |
| mmap_read_unlock(current->mm); |
| if (ret) { |
| /* |
| * if we did partial map, or found file backed vmas, |
| * release any pages we did get |
| */ |
| if (pret > 0) |
| unpin_user_pages(pages, pret); |
| io_unaccount_mem(ctx, nr_pages, ACCT_PINNED); |
| kvfree(imu->bvec); |
| goto err; |
| } |
| |
| off = ubuf & ~PAGE_MASK; |
| size = iov.iov_len; |
| for (j = 0; j < nr_pages; j++) { |
| size_t vec_len; |
| |
| vec_len = min_t(size_t, size, PAGE_SIZE - off); |
| imu->bvec[j].bv_page = pages[j]; |
| imu->bvec[j].bv_len = vec_len; |
| imu->bvec[j].bv_offset = off; |
| off = 0; |
| size -= vec_len; |
| } |
| /* store original address for later verification */ |
| imu->ubuf = ubuf; |
| imu->len = iov.iov_len; |
| imu->nr_bvecs = nr_pages; |
| |
| ctx->nr_user_bufs++; |
| } |
| kvfree(pages); |
| kvfree(vmas); |
| return 0; |
| err: |
| kvfree(pages); |
| kvfree(vmas); |
| io_sqe_buffer_unregister(ctx); |
| return ret; |
| } |
| |
| static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg) |
| { |
| __s32 __user *fds = arg; |
| int fd; |
| |
| if (ctx->cq_ev_fd) |
| return -EBUSY; |
| |
| if (copy_from_user(&fd, fds, sizeof(*fds))) |
| return -EFAULT; |
| |
| ctx->cq_ev_fd = eventfd_ctx_fdget(fd); |
| if (IS_ERR(ctx->cq_ev_fd)) { |
| int ret = PTR_ERR(ctx->cq_ev_fd); |
| ctx->cq_ev_fd = NULL; |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int io_eventfd_unregister(struct io_ring_ctx *ctx) |
| { |
| if (ctx->cq_ev_fd) { |
| eventfd_ctx_put(ctx->cq_ev_fd); |
| ctx->cq_ev_fd = NULL; |
| return 0; |
| } |
| |
| return -ENXIO; |
| } |
| |
| static int __io_destroy_buffers(int id, void *p, void *data) |
| { |
| struct io_ring_ctx *ctx = data; |
| struct io_buffer *buf = p; |
| |
| __io_remove_buffers(ctx, buf, id, -1U); |
| return 0; |
| } |
| |
| static void io_destroy_buffers(struct io_ring_ctx *ctx) |
| { |
| idr_for_each(&ctx->io_buffer_idr, __io_destroy_buffers, ctx); |
| idr_destroy(&ctx->io_buffer_idr); |
| } |
| |
| static void io_ring_ctx_free(struct io_ring_ctx *ctx) |
| { |
| io_finish_async(ctx); |
| io_sqe_buffer_unregister(ctx); |
| if (ctx->sqo_mm) { |
| mmdrop(ctx->sqo_mm); |
| ctx->sqo_mm = NULL; |
| } |
| |
| io_sqe_files_unregister(ctx); |
| io_eventfd_unregister(ctx); |
| io_destroy_buffers(ctx); |
| idr_destroy(&ctx->personality_idr); |
| |
| #if defined(CONFIG_UNIX) |
| if (ctx->ring_sock) { |
| ctx->ring_sock->file = NULL; /* so that iput() is called */ |
| sock_release(ctx->ring_sock); |
| } |
| #endif |
| |
| io_mem_free(ctx->rings); |
| io_mem_free(ctx->sq_sqes); |
| |
| percpu_ref_exit(&ctx->refs); |
| free_uid(ctx->user); |
| put_cred(ctx->creds); |
| kfree(ctx->cancel_hash); |
| kmem_cache_free(req_cachep, ctx->fallback_req); |
| kfree(ctx); |
| } |
| |
| static __poll_t io_uring_poll(struct file *file, poll_table *wait) |
| { |
| struct io_ring_ctx *ctx = file->private_data; |
| __poll_t mask = 0; |
| |
| poll_wait(file, &ctx->cq_wait, wait); |
| /* |
| * synchronizes with barrier from wq_has_sleeper call in |
| * io_commit_cqring |
| */ |
| smp_rmb(); |
| if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head != |
| ctx->rings->sq_ring_entries) |
| mask |= EPOLLOUT | EPOLLWRNORM; |
| if (io_cqring_events(ctx, false)) |
| mask |= EPOLLIN | EPOLLRDNORM; |
| |
| return mask; |
| } |
| |
| static int io_uring_fasync(int fd, struct file *file, int on) |
| { |
| struct io_ring_ctx *ctx = file->private_data; |
| |
| return fasync_helper(fd, file, on, &ctx->cq_fasync); |
| } |
| |
| static int io_remove_personalities(int id, void *p, void *data) |
| { |
| struct io_ring_ctx *ctx = data; |
| const struct cred *cred; |
| |
| cred = idr_remove(&ctx->personality_idr, id); |
| if (cred) |
| put_cred(cred); |
| return 0; |
| } |
| |
| static void io_ring_exit_work(struct work_struct *work) |
| { |
| struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, |
| exit_work); |
| |
| /* |
| * If we're doing polled IO and end up having requests being |
| * submitted async (out-of-line), then completions can come in while |
| * we're waiting for refs to drop. We need to reap these manually, |
| * as nobody else will be looking for them. |
| */ |
| do { |
| if (ctx->rings) |
| io_cqring_overflow_flush(ctx, true); |
| io_iopoll_try_reap_events(ctx); |
| } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20)); |
| io_ring_ctx_free(ctx); |
| } |
| |
| static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) |
| { |
| mutex_lock(&ctx->uring_lock); |
| percpu_ref_kill(&ctx->refs); |
| mutex_unlock(&ctx->uring_lock); |
| |
| io_kill_timeouts(ctx); |
| io_poll_remove_all(ctx); |
| |
| if (ctx->io_wq) |
| io_wq_cancel_all(ctx->io_wq); |
| |
| /* if we failed setting up the ctx, we might not have any rings */ |
| if (ctx->rings) |
| io_cqring_overflow_flush(ctx, true); |
| io_iopoll_try_reap_events(ctx); |
| idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx); |
| |
| /* |
| * Do this upfront, so we won't have a grace period where the ring |
| * is closed but resources aren't reaped yet. This can cause |
| * spurious failure in setting up a new ring. |
| */ |
| io_unaccount_mem(ctx, ring_pages(ctx->sq_entries, ctx->cq_entries), |
| ACCT_LOCKED); |
| |
| INIT_WORK(&ctx->exit_work, io_ring_exit_work); |
| /* |
| * Use system_unbound_wq to avoid spawning tons of event kworkers |
| * if we're exiting a ton of rings at the same time. It just adds |
| * noise and overhead, there's no discernable change in runtime |
| * over using system_wq. |
| */ |
| queue_work(system_unbound_wq, &ctx->exit_work); |
| } |
| |
| static int io_uring_release(struct inode *inode, struct file *file) |
| { |
| struct io_ring_ctx *ctx = file->private_data; |
| |
| file->private_data = NULL; |
| io_ring_ctx_wait_and_kill(ctx); |
| return 0; |
| } |
| |
| static bool io_wq_files_match(struct io_wq_work *work, void *data) |
| { |
| struct files_struct *files = data; |
| |
| return work->files == files; |
| } |
| |
| /* |
| * Returns true if 'preq' is the link parent of 'req' |
| */ |
| static bool io_match_link(struct io_kiocb *preq, struct io_kiocb *req) |
| { |
| struct io_kiocb *link; |
| |
| if (!(preq->flags & REQ_F_LINK_HEAD)) |
| return false; |
| |
| list_for_each_entry(link, &preq->link_list, link_list) { |
| if (link == req) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static inline bool io_match_files(struct io_kiocb *req, |
| struct files_struct *files) |
| { |
| return (req->flags & REQ_F_WORK_INITIALIZED) && req->work.files == files; |
| } |
| |
| static bool io_match_link_files(struct io_kiocb *req, |
| struct files_struct *files) |
| { |
| struct io_kiocb *link; |
| |
| if (io_match_files(req, files)) |
| return true; |
| if (req->flags & REQ_F_LINK_HEAD) { |
| list_for_each_entry(link, &req->link_list, link_list) { |
| if (io_match_files(link, files)) |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /* |
| * We're looking to cancel 'req' because it's holding on to our files, but |
| * 'req' could be a link to another request. See if it is, and cancel that |
| * parent request if so. |
| */ |
| static bool io_poll_remove_link(struct io_ring_ctx *ctx, struct io_kiocb *req) |
| { |
| struct hlist_node *tmp; |
| struct io_kiocb *preq; |
| bool found = false; |
| int i; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { |
| struct hlist_head *list; |
| |
| list = &ctx->cancel_hash[i]; |
| hlist_for_each_entry_safe(preq, tmp, list, hash_node) { |
| found = io_match_link(preq, req); |
| if (found) { |
| io_poll_remove_one(preq); |
| break; |
| } |
| } |
| } |
| spin_unlock_irq(&ctx->completion_lock); |
| return found; |
| } |
| |
| static bool io_timeout_remove_link(struct io_ring_ctx *ctx, |
| struct io_kiocb *req) |
| { |
| struct io_kiocb *preq; |
| bool found = false; |
| |
| spin_lock_irq(&ctx->completion_lock); |
| list_for_each_entry(preq, &ctx->timeout_list, timeout.list) { |
| found = io_match_link(preq, req); |
| if (found) { |
| __io_timeout_cancel(preq); |
| break; |
| } |
| } |
| spin_unlock_irq(&ctx->completion_lock); |
| return found; |
| } |
| |
| static bool io_cancel_link_cb(struct io_wq_work *work, void *data) |
| { |
| return io_match_link(container_of(work, struct io_kiocb, work), data); |
| } |
| |
| static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req) |
| { |
| enum io_wq_cancel cret; |
| |
| /* cancel this particular work, if it's running */ |
| cret = io_wq_cancel_work(ctx->io_wq, &req->work); |
| if (cret != IO_WQ_CANCEL_NOTFOUND) |
| return; |
| |
| /* find links that hold this pending, cancel those */ |
| cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_link_cb, req, true); |
| if (cret != IO_WQ_CANCEL_NOTFOUND) |
| return; |
| |
| /* if we have a poll link holding this pending, cancel that */ |
| if (io_poll_remove_link(ctx, req)) |
| return; |
| |
| /* final option, timeout link is holding this req pending */ |
| io_timeout_remove_link(ctx, req); |
| } |
| |
| static void io_cancel_defer_files(struct io_ring_ctx *ctx, |
| struct files_struct *files) |
| { |
| struct io_defer_entry *de = NULL; |
| LIST_HEAD(list); |
| |
| spin_lock_irq(&ctx->completion_lock); |
| list_for_each_entry_reverse(de, &ctx->defer_list, list) { |
| if (io_match_link_files(de->req, files)) { |
| list_cut_position(&list, &ctx->defer_list, &de->list); |
| break; |
| } |
| } |
| spin_unlock_irq(&ctx->completion_lock); |
| |
| while (!list_empty(&list)) { |
| de = list_first_entry(&list, struct io_defer_entry, list); |
| list_del_init(&de->list); |
| req_set_fail_links(de->req); |
| io_put_req(de->req); |
| io_req_complete(de->req, -ECANCELED); |
| kfree(de); |
| } |
| } |
| |
| static void io_uring_cancel_files(struct io_ring_ctx *ctx, |
| struct files_struct *files) |
| { |
| if (list_empty_careful(&ctx->inflight_list)) |
| return; |
| |
| io_cancel_defer_files(ctx, files); |
| /* cancel all at once, should be faster than doing it one by one*/ |
| io_wq_cancel_cb(ctx->io_wq, io_wq_files_match, files, true); |
| |
| while (!list_empty_careful(&ctx->inflight_list)) { |
| struct io_kiocb *cancel_req = NULL, *req; |
| DEFINE_WAIT(wait); |
| |
| spin_lock_irq(&ctx->inflight_lock); |
| list_for_each_entry(req, &ctx->inflight_list, inflight_entry) { |
| if (req->work.files != files) |
| continue; |
| /* req is being completed, ignore */ |
| if (!refcount_inc_not_zero(&req->refs)) |
| continue; |
| cancel_req = req; |
| break; |
| } |
| if (cancel_req) |
| prepare_to_wait(&ctx->inflight_wait, &wait, |
| TASK_UNINTERRUPTIBLE); |
| spin_unlock_irq(&ctx->inflight_lock); |
| |
| /* We need to keep going until we don't find a matching req */ |
| if (!cancel_req) |
| break; |
| /* cancel this request, or head link requests */ |
| io_attempt_cancel(ctx, cancel_req); |
| io_put_req(cancel_req); |
| /* cancellations _may_ trigger task work */ |
| io_run_task_work(); |
| schedule(); |
| finish_wait(&ctx->inflight_wait, &wait); |
| } |
| } |
| |
| static bool io_cancel_task_cb(struct io_wq_work *work, void *data) |
| { |
| struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
| struct task_struct *task = data; |
| |
| return req->task == task; |
| } |
| |
| static int io_uring_flush(struct file *file, void *data) |
| { |
| struct io_ring_ctx *ctx = file->private_data; |
| |
| io_uring_cancel_files(ctx, data); |
| |
| /* |
| * If the task is going away, cancel work it may have pending |
| */ |
| if (fatal_signal_pending(current) || (current->flags & PF_EXITING)) |
| io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, current, true); |
| |
| return 0; |
| } |
| |
| static void *io_uring_validate_mmap_request(struct file *file, |
| loff_t pgoff, size_t sz) |
| { |
| struct io_ring_ctx *ctx = file->private_data; |
| loff_t offset = pgoff << PAGE_SHIFT; |
| struct page *page; |
| void *ptr; |
| |
| switch (offset) { |
| case IORING_OFF_SQ_RING: |
| case IORING_OFF_CQ_RING: |
| ptr = ctx->rings; |
| break; |
| case IORING_OFF_SQES: |
| ptr = ctx->sq_sqes; |
| break; |
| default: |
| return ERR_PTR(-EINVAL); |
| } |
| |
| page = virt_to_head_page(ptr); |
| if (sz > page_size(page)) |
| return ERR_PTR(-EINVAL); |
| |
| return ptr; |
| } |
| |
| #ifdef CONFIG_MMU |
| |
| static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| size_t sz = vma->vm_end - vma->vm_start; |
| unsigned long pfn; |
| void *ptr; |
| |
| ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz); |
| if (IS_ERR(ptr)) |
| return PTR_ERR(ptr); |
| |
| pfn = virt_to_phys(ptr) >> PAGE_SHIFT; |
| return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); |
| } |
| |
| #else /* !CONFIG_MMU */ |
| |
| static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL; |
| } |
| |
| static unsigned int io_uring_nommu_mmap_capabilities(struct file *file) |
| { |
| return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE; |
| } |
| |
| static unsigned long io_uring_nommu_get_unmapped_area(struct file *file, |
| unsigned long addr, unsigned long len, |
| unsigned long pgoff, unsigned long flags) |
| { |
| void *ptr; |
| |
| ptr = io_uring_validate_mmap_request(file, pgoff, len); |
| if (IS_ERR(ptr)) |
| return PTR_ERR(ptr); |
| |
| return (unsigned long) ptr; |
| } |
| |
| #endif /* !CONFIG_MMU */ |
| |
| SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, |
| u32, min_complete, u32, flags, const sigset_t __user *, sig, |
| size_t, sigsz) |
| { |
| struct io_ring_ctx *ctx; |
| long ret = -EBADF; |
| int submitted = 0; |
| struct fd f; |
| |
| io_run_task_work(); |
| |
| if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP)) |
| return -EINVAL; |
| |
| f = fdget(fd); |
| if (!f.file) |
| return -EBADF; |
| |
| ret = -EOPNOTSUPP; |
| if (f.file->f_op != &io_uring_fops) |
| goto out_fput; |
| |
| ret = -ENXIO; |
| ctx = f.file->private_data; |
| if (!percpu_ref_tryget(&ctx->refs)) |
| goto out_fput; |
| |
| /* |
| * For SQ polling, the thread will do all submissions and completions. |
| * Just return the requested submit count, and wake the thread if |
| * we were asked to. |
| */ |
| ret = 0; |
| if (ctx->flags & IORING_SETUP_SQPOLL) { |
| if (!list_empty_careful(&ctx->cq_overflow_list)) |
| io_cqring_overflow_flush(ctx, false); |
| if (flags & IORING_ENTER_SQ_WAKEUP) |
| wake_up(&ctx->sqo_wait); |
| submitted = to_submit; |
| } else if (to_submit) { |
| mutex_lock(&ctx->uring_lock); |
| submitted = io_submit_sqes(ctx, to_submit, f.file, fd); |
| mutex_unlock(&ctx->uring_lock); |
| |
| if (submitted != to_submit) |
| goto out; |
| } |
| if (flags & IORING_ENTER_GETEVENTS) { |
| min_complete = min(min_complete, ctx->cq_entries); |
| |
| /* |
| * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user |
| * space applications don't need to do io completion events |
| * polling again, they can rely on io_sq_thread to do polling |
| * work, which can reduce cpu usage and uring_lock contention. |
| */ |
| if (ctx->flags & IORING_SETUP_IOPOLL && |
| !(ctx->flags & IORING_SETUP_SQPOLL)) { |
| ret = io_iopoll_check(ctx, min_complete); |
| } else { |
| ret = io_cqring_wait(ctx, min_complete, sig, sigsz); |
| } |
| } |
| |
| out: |
| percpu_ref_put(&ctx->refs); |
| out_fput: |
| fdput(f); |
| return submitted ? submitted : ret; |
| } |
| |
| #ifdef CONFIG_PROC_FS |
| static int io_uring_show_cred(int id, void *p, void *data) |
| { |
| const struct cred *cred = p; |
| struct seq_file *m = data; |
| struct user_namespace *uns = seq_user_ns(m); |
| struct group_info *gi; |
| kernel_cap_t cap; |
| unsigned __capi; |
| int g; |
| |
| seq_printf(m, "%5d\n", id); |
| seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid)); |
| seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid)); |
| seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid)); |
| seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid)); |
| seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid)); |
| seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid)); |
| seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid)); |
| seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid)); |
| seq_puts(m, "\n\tGroups:\t"); |
| gi = cred->group_info; |
| for (g = 0; g < gi->ngroups; g++) { |
| seq_put_decimal_ull(m, g ? " " : "", |
| from_kgid_munged(uns, gi->gid[g])); |
| } |
| seq_puts(m, "\n\tCapEff:\t"); |
| cap = cred->cap_effective; |
| CAP_FOR_EACH_U32(__capi) |
| seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8); |
| seq_putc(m, '\n'); |
| return 0; |
| } |
| |
| static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) |
| { |
| bool has_lock; |
| int i; |
| |
| /* |
| * Avoid ABBA deadlock between the seq lock and the io_uring mutex, |
| * since fdinfo case grabs it in the opposite direction of normal use |
| * cases. If we fail to get the lock, we just don't iterate any |
| * structures that could be going away outside the io_uring mutex. |
| */ |
| has_lock = mutex_trylock(&ctx->uring_lock); |
| |
| seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files); |
| for (i = 0; has_lock && i < ctx->nr_user_files; i++) { |
| struct fixed_file_table *table; |
| struct file *f; |
| |
| table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT]; |
| f = table->files[i & IORING_FILE_TABLE_MASK]; |
| if (f) |
| seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname); |
| else |
| seq_printf(m, "%5u: <none>\n", i); |
| } |
| seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs); |
| for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) { |
| struct io_mapped_ubuf *buf = &ctx->user_bufs[i]; |
| |
| seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, |
| (unsigned int) buf->len); |
| } |
| if (has_lock && !idr_is_empty(&ctx->personality_idr)) { |
| seq_printf(m, "Personalities:\n"); |
| idr_for_each(&ctx->personality_idr, io_uring_show_cred, m); |
| } |
| seq_printf(m, "PollList:\n"); |
| spin_lock_irq(&ctx->completion_lock); |
| for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { |
| struct hlist_head *list = &ctx->cancel_hash[i]; |
| struct io_kiocb *req; |
| |
| hlist_for_each_entry(req, list, hash_node) |
| seq_printf(m, " op=%d, task_works=%d\n", req->opcode, |
| req->task->task_works != NULL); |
| } |
| spin_unlock_irq(&ctx->completion_lock); |
| if (has_lock) |
| mutex_unlock(&ctx->uring_lock); |
| } |
| |
| static void io_uring_show_fdinfo(struct seq_file *m, struct file *f) |
| { |
| struct io_ring_ctx *ctx = f->private_data; |
| |
| if (percpu_ref_tryget(&ctx->refs)) { |
| __io_uring_show_fdinfo(ctx, m); |
| percpu_ref_put(&ctx->refs); |
| } |
| } |
| #endif |
| |
| static const struct file_operations io_uring_fops = { |
| .release = io_uring_release, |
| .flush = io_uring_flush, |
| .mmap = io_uring_mmap, |
| #ifndef CONFIG_MMU |
| .get_unmapped_area = io_uring_nommu_get_unmapped_area, |
| .mmap_capabilities = io_uring_nommu_mmap_capabilities, |
| #endif |
| .poll = io_uring_poll, |
| .fasync = io_uring_fasync, |
| #ifdef CONFIG_PROC_FS |
| .show_fdinfo = io_uring_show_fdinfo, |
| #endif |
| }; |
| |
| static int io_allocate_scq_urings(struct io_ring_ctx *ctx, |
| struct io_uring_params *p) |
| { |
| struct io_rings *rings; |
| size_t size, sq_array_offset; |
| |
| /* make sure these are sane, as we already accounted them */ |
| ctx->sq_entries = p->sq_entries; |
| ctx->cq_entries = p->cq_entries; |
| |
| size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset); |
| if (size == SIZE_MAX) |
| return -EOVERFLOW; |
| |
| rings = io_mem_alloc(size); |
| if (!rings) |
| return -ENOMEM; |
| |
| ctx->rings = rings; |
| ctx->sq_array = (u32 *)((char *)rings + sq_array_offset); |
| rings->sq_ring_mask = p->sq_entries - 1; |
| rings->cq_ring_mask = p->cq_entries - 1; |
| rings->sq_ring_entries = p->sq_entries; |
| rings->cq_ring_entries = p->cq_entries; |
| ctx->sq_mask = rings->sq_ring_mask; |
| ctx->cq_mask = rings->cq_ring_mask; |
| |
| size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); |
| if (size == SIZE_MAX) { |
| io_mem_free(ctx->rings); |
| ctx->rings = NULL; |
| return -EOVERFLOW; |
| } |
| |
| ctx->sq_sqes = io_mem_alloc(size); |
| if (!ctx->sq_sqes) { |
| io_mem_free(ctx->rings); |
| ctx->rings = NULL; |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Allocate an anonymous fd, this is what constitutes the application |
| * visible backing of an io_uring instance. The application mmaps this |
| * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled, |
| * we have to tie this fd to a socket for file garbage collection purposes. |
| */ |
| static int io_uring_get_fd(struct io_ring_ctx *ctx) |
| { |
| struct file *file; |
| int ret; |
| |
| #if defined(CONFIG_UNIX) |
| ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP, |
| &ctx->ring_sock); |
| if (ret) |
| return ret; |
| #endif |
| |
| ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC); |
| if (ret < 0) |
| goto err; |
| |
| file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx, |
| O_RDWR | O_CLOEXEC); |
| if (IS_ERR(file)) { |
| put_unused_fd(ret); |
| ret = PTR_ERR(file); |
| goto err; |
| } |
| |
| #if defined(CONFIG_UNIX) |
| ctx->ring_sock->file = file; |
| #endif |
| fd_install(ret, file); |
| return ret; |
| err: |
| #if defined(CONFIG_UNIX) |
| sock_release(ctx->ring_sock); |
| ctx->ring_sock = NULL; |
| #endif |
| return ret; |
| } |
| |
| static int io_uring_create(unsigned entries, struct io_uring_params *p, |
| struct io_uring_params __user *params) |
| { |
| struct user_struct *user = NULL; |
| struct io_ring_ctx *ctx; |
| bool limit_mem; |
| int ret; |
| |
| if (!entries) |
| return -EINVAL; |
| if (entries > IORING_MAX_ENTRIES) { |
| if (!(p->flags & IORING_SETUP_CLAMP)) |
| return -EINVAL; |
| entries = IORING_MAX_ENTRIES; |
| } |
| |
| /* |
| * Use twice as many entries for the CQ ring. It's possible for the |
| * application to drive a higher depth than the size of the SQ ring, |
| * since the sqes are only used at submission time. This allows for |
| * some flexibility in overcommitting a bit. If the application has |
| * set IORING_SETUP_CQSIZE, it will have passed in the desired number |
| * of CQ ring entries manually. |
| */ |
| p->sq_entries = roundup_pow_of_two(entries); |
| if (p->flags & IORING_SETUP_CQSIZE) { |
| /* |
| * If IORING_SETUP_CQSIZE is set, we do the same roundup |
| * to a power-of-two, if it isn't already. We do NOT impose |
| * any cq vs sq ring sizing. |
| */ |
| if (p->cq_entries < p->sq_entries) |
| return -EINVAL; |
| if (p->cq_entries > IORING_MAX_CQ_ENTRIES) { |
| if (!(p->flags & IORING_SETUP_CLAMP)) |
| return -EINVAL; |
| p->cq_entries = IORING_MAX_CQ_ENTRIES; |
| } |
| p->cq_entries = roundup_pow_of_two(p->cq_entries); |
| } else { |
| p->cq_entries = 2 * p->sq_entries; |
| } |
| |
| user = get_uid(current_user()); |
| limit_mem = !capable(CAP_IPC_LOCK); |
| |
| if (limit_mem) { |
| ret = __io_account_mem(user, |
| ring_pages(p->sq_entries, p->cq_entries)); |
| if (ret) { |
| free_uid(user); |
| return ret; |
| } |
| } |
| |
| ctx = io_ring_ctx_alloc(p); |
| if (!ctx) { |
| if (limit_mem) |
| __io_unaccount_mem(user, ring_pages(p->sq_entries, |
| p->cq_entries)); |
| free_uid(user); |
| return -ENOMEM; |
| } |
| ctx->compat = in_compat_syscall(); |
| ctx->user = user; |
| ctx->creds = get_current_cred(); |
| |
| mmgrab(current->mm); |
| ctx->sqo_mm = current->mm; |
| |
| /* |
| * Account memory _before_ installing the file descriptor. Once |
| * the descriptor is installed, it can get closed at any time. Also |
| * do this before hitting the general error path, as ring freeing |
| * will un-account as well. |
| */ |
| io_account_mem(ctx, ring_pages(p->sq_entries, p->cq_entries), |
| ACCT_LOCKED); |
| ctx->limit_mem = limit_mem; |
| |
| ret = io_allocate_scq_urings(ctx, p); |
| if (ret) |
| goto err; |
| |
| ret = io_sq_offload_start(ctx, p); |
| if (ret) |
| goto err; |
| |
| memset(&p->sq_off, 0, sizeof(p->sq_off)); |
| p->sq_off.head = offsetof(struct io_rings, sq.head); |
| p->sq_off.tail = offsetof(struct io_rings, sq.tail); |
| p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask); |
| p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries); |
| p->sq_off.flags = offsetof(struct io_rings, sq_flags); |
| p->sq_off.dropped = offsetof(struct io_rings, sq_dropped); |
| p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings; |
| |
| memset(&p->cq_off, 0, sizeof(p->cq_off)); |
| p->cq_off.head = offsetof(struct io_rings, cq.head); |
| p->cq_off.tail = offsetof(struct io_rings, cq.tail); |
| p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask); |
| p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries); |
| p->cq_off.overflow = offsetof(struct io_rings, cq_overflow); |
| p->cq_off.cqes = offsetof(struct io_rings, cqes); |
| p->cq_off.flags = offsetof(struct io_rings, cq_flags); |
| |
| p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP | |
| IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS | |
| IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL | |
| IORING_FEAT_POLL_32BITS; |
| |
| if (copy_to_user(params, p, sizeof(*p))) { |
| ret = -EFAULT; |
| goto err; |
| } |
| |
| /* |
| * Install ring fd as the very last thing, so we don't risk someone |
| * having closed it before we finish setup |
| */ |
| ret = io_uring_get_fd(ctx); |
| if (ret < 0) |
| goto err; |
| |
| trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); |
| return ret; |
| err: |
| io_ring_ctx_wait_and_kill(ctx); |
| return ret; |
| } |
| |
| /* |
| * Sets up an aio uring context, and returns the fd. Applications asks for a |
| * ring size, we return the actual sq/cq ring sizes (among other things) in the |
| * params structure passed in. |
| */ |
| static long io_uring_setup(u32 entries, struct io_uring_params __user *params) |
| { |
| struct io_uring_params p; |
| int i; |
| |
| if (copy_from_user(&p, params, sizeof(p))) |
| return -EFAULT; |
| for (i = 0; i < ARRAY_SIZE(p.resv); i++) { |
| if (p.resv[i]) |
| return -EINVAL; |
| } |
| |
| if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL | |
| IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE | |
| IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ)) |
| return -EINVAL; |
| |
| return io_uring_create(entries, &p, params); |
| } |
| |
| SYSCALL_DEFINE2(io_uring_setup, u32, entries, |
| struct io_uring_params __user *, params) |
| { |
| return io_uring_setup(entries, params); |
| } |
| |
| static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) |
| { |
| struct io_uring_probe *p; |
| size_t size; |
| int i, ret; |
| |
| size = struct_size(p, ops, nr_args); |
| if (size == SIZE_MAX) |
| return -EOVERFLOW; |
| p = kzalloc(size, GFP_KERNEL); |
| if (!p) |
| return -ENOMEM; |
| |
| ret = -EFAULT; |
| if (copy_from_user(p, arg, size)) |
| goto out; |
| ret = -EINVAL; |
| if (memchr_inv(p, 0, size)) |
| goto out; |
| |
| p->last_op = IORING_OP_LAST - 1; |
| if (nr_args > IORING_OP_LAST) |
| nr_args = IORING_OP_LAST; |
| |
| for (i = 0; i < nr_args; i++) { |
| p->ops[i].op = i; |
| if (!io_op_defs[i].not_supported) |
| p->ops[i].flags = IO_URING_OP_SUPPORTED; |
| } |
| p->ops_len = i; |
| |
| ret = 0; |
| if (copy_to_user(arg, p, size)) |
| ret = -EFAULT; |
| out: |
| kfree(p); |
| return ret; |
| } |
| |
| static int io_register_personality(struct io_ring_ctx *ctx) |
| { |
| const struct cred *creds = get_current_cred(); |
| int id; |
| |
| id = idr_alloc_cyclic(&ctx->personality_idr, (void *) creds, 1, |
| USHRT_MAX, GFP_KERNEL); |
| if (id < 0) |
| put_cred(creds); |
| return id; |
| } |
| |
| static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) |
| { |
| const struct cred *old_creds; |
| |
| old_creds = idr_remove(&ctx->personality_idr, id); |
| if (old_creds) { |
| put_cred(old_creds); |
| return 0; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static bool io_register_op_must_quiesce(int op) |
| { |
| switch (op) { |
| case IORING_UNREGISTER_FILES: |
| case IORING_REGISTER_FILES_UPDATE: |
| case IORING_REGISTER_PROBE: |
| case IORING_REGISTER_PERSONALITY: |
| case IORING_UNREGISTER_PERSONALITY: |
| return false; |
| default: |
| return true; |
| } |
| } |
| |
| static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, |
| void __user *arg, unsigned nr_args) |
| __releases(ctx->uring_lock) |
| __acquires(ctx->uring_lock) |
| { |
| int ret; |
| |
| /* |
| * We're inside the ring mutex, if the ref is already dying, then |
| * someone else killed the ctx or is already going through |
| * io_uring_register(). |
| */ |
| if (percpu_ref_is_dying(&ctx->refs)) |
| return -ENXIO; |
| |
| if (io_register_op_must_quiesce(opcode)) { |
| percpu_ref_kill(&ctx->refs); |
| |
| /* |
| * Drop uring mutex before waiting for references to exit. If |
| * another thread is currently inside io_uring_enter() it might |
| * need to grab the uring_lock to make progress. If we hold it |
| * here across the drain wait, then we can deadlock. It's safe |
| * to drop the mutex here, since no new references will come in |
| * after we've killed the percpu ref. |
| */ |
| mutex_unlock(&ctx->uring_lock); |
| ret = wait_for_completion_interruptible(&ctx->ref_comp); |
| mutex_lock(&ctx->uring_lock); |
| if (ret) { |
| percpu_ref_resurrect(&ctx->refs); |
| ret = -EINTR; |
| goto out; |
| } |
| } |
| |
| switch (opcode) { |
| case IORING_REGISTER_BUFFERS: |
| ret = io_sqe_buffer_register(ctx, arg, nr_args); |
| break; |
| case IORING_UNREGISTER_BUFFERS: |
| ret = -EINVAL; |
| if (arg || nr_args) |
| break; |
| ret = io_sqe_buffer_unregister(ctx); |
| break; |
| case IORING_REGISTER_FILES: |
| ret = io_sqe_files_register(ctx, arg, nr_args); |
| break; |
| case IORING_UNREGISTER_FILES: |
| ret = -EINVAL; |
| if (arg || nr_args) |
| break; |
| ret = io_sqe_files_unregister(ctx); |
| break; |
| case IORING_REGISTER_FILES_UPDATE: |
| ret = io_sqe_files_update(ctx, arg, nr_args); |
| break; |
| case IORING_REGISTER_EVENTFD: |
| case IORING_REGISTER_EVENTFD_ASYNC: |
| ret = -EINVAL; |
| if (nr_args != 1) |
| break; |
| ret = io_eventfd_register(ctx, arg); |
| if (ret) |
| break; |
| if (opcode == IORING_REGISTER_EVENTFD_ASYNC) |
| ctx->eventfd_async = 1; |
| else |
| ctx->eventfd_async = 0; |
| break; |
| case IORING_UNREGISTER_EVENTFD: |
| ret = -EINVAL; |
| if (arg || nr_args) |
| break; |
| ret = io_eventfd_unregister(ctx); |
| break; |
| case IORING_REGISTER_PROBE: |
| ret = -EINVAL; |
| if (!arg || nr_args > 256) |
| break; |
| ret = io_probe(ctx, arg, nr_args); |
| break; |
| case IORING_REGISTER_PERSONALITY: |
| ret = -EINVAL; |
| if (arg || nr_args) |
| break; |
| ret = io_register_personality(ctx); |
| break; |
| case IORING_UNREGISTER_PERSONALITY: |
| ret = -EINVAL; |
| if (arg) |
| break; |
| ret = io_unregister_personality(ctx, nr_args); |
| break; |
| default: |
| ret = -EINVAL; |
| break; |
| } |
| |
| if (io_register_op_must_quiesce(opcode)) { |
| /* bring the ctx back to life */ |
| percpu_ref_reinit(&ctx->refs); |
| out: |
| reinit_completion(&ctx->ref_comp); |
| } |
| return ret; |
| } |
| |
| SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, |
| void __user *, arg, unsigned int, nr_args) |
| { |
| struct io_ring_ctx *ctx; |
| long ret = -EBADF; |
| struct fd f; |
| |
| f = fdget(fd); |
| if (!f.file) |
| return -EBADF; |
| |
| ret = -EOPNOTSUPP; |
| if (f.file->f_op != &io_uring_fops) |
| goto out_fput; |
| |
| ctx = f.file->private_data; |
| |
| mutex_lock(&ctx->uring_lock); |
| ret = __io_uring_register(ctx, opcode, arg, nr_args); |
| mutex_unlock(&ctx->uring_lock); |
| trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs, |
| ctx->cq_ev_fd != NULL, ret); |
| out_fput: |
| fdput(f); |
| return ret; |
| } |
| |
| static int __init io_uring_init(void) |
| { |
| #define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \ |
| BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \ |
| BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \ |
| } while (0) |
| |
| #define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \ |
| __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename) |
| BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64); |
| BUILD_BUG_SQE_ELEM(0, __u8, opcode); |
| BUILD_BUG_SQE_ELEM(1, __u8, flags); |
| BUILD_BUG_SQE_ELEM(2, __u16, ioprio); |
| BUILD_BUG_SQE_ELEM(4, __s32, fd); |
| BUILD_BUG_SQE_ELEM(8, __u64, off); |
| BUILD_BUG_SQE_ELEM(8, __u64, addr2); |
| BUILD_BUG_SQE_ELEM(16, __u64, addr); |
| BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in); |
| BUILD_BUG_SQE_ELEM(24, __u32, len); |
| BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags); |
| BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags); |
| BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags); |
| BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags); |
| BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events); |
| BUILD_BUG_SQE_ELEM(28, __u32, poll32_events); |
| BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags); |
| BUILD_BUG_SQE_ELEM(28, __u32, msg_flags); |
| BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags); |
| BUILD_BUG_SQE_ELEM(28, __u32, accept_flags); |
| BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags); |
| BUILD_BUG_SQE_ELEM(28, __u32, open_flags); |
| BUILD_BUG_SQE_ELEM(28, __u32, statx_flags); |
| BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice); |
| BUILD_BUG_SQE_ELEM(28, __u32, splice_flags); |
| BUILD_BUG_SQE_ELEM(32, __u64, user_data); |
| BUILD_BUG_SQE_ELEM(40, __u16, buf_index); |
| BUILD_BUG_SQE_ELEM(42, __u16, personality); |
| BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in); |
| |
| BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST); |
| BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int)); |
| req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC); |
| return 0; |
| }; |
| __initcall(io_uring_init); |