| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Userspace block device - block device which IO is handled from userspace |
| * |
| * Take full use of io_uring passthrough command for communicating with |
| * ublk userspace daemon(ublksrvd) for handling basic IO request. |
| * |
| * Copyright 2022 Ming Lei <ming.lei@redhat.com> |
| * |
| * (part of code stolen from loop.c) |
| */ |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/sched.h> |
| #include <linux/fs.h> |
| #include <linux/pagemap.h> |
| #include <linux/file.h> |
| #include <linux/stat.h> |
| #include <linux/errno.h> |
| #include <linux/major.h> |
| #include <linux/wait.h> |
| #include <linux/blkdev.h> |
| #include <linux/init.h> |
| #include <linux/swap.h> |
| #include <linux/slab.h> |
| #include <linux/compat.h> |
| #include <linux/mutex.h> |
| #include <linux/writeback.h> |
| #include <linux/completion.h> |
| #include <linux/highmem.h> |
| #include <linux/sysfs.h> |
| #include <linux/miscdevice.h> |
| #include <linux/falloc.h> |
| #include <linux/uio.h> |
| #include <linux/ioprio.h> |
| #include <linux/sched/mm.h> |
| #include <linux/uaccess.h> |
| #include <linux/cdev.h> |
| #include <linux/io_uring/cmd.h> |
| #include <linux/blk-mq.h> |
| #include <linux/delay.h> |
| #include <linux/mm.h> |
| #include <asm/page.h> |
| #include <linux/task_work.h> |
| #include <linux/namei.h> |
| #include <linux/kref.h> |
| #include <uapi/linux/ublk_cmd.h> |
| |
| #define UBLK_MINORS (1U << MINORBITS) |
| |
| /* private ioctl command mirror */ |
| #define UBLK_CMD_DEL_DEV_ASYNC _IOC_NR(UBLK_U_CMD_DEL_DEV_ASYNC) |
| |
| /* All UBLK_F_* have to be included into UBLK_F_ALL */ |
| #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \ |
| | UBLK_F_URING_CMD_COMP_IN_TASK \ |
| | UBLK_F_NEED_GET_DATA \ |
| | UBLK_F_USER_RECOVERY \ |
| | UBLK_F_USER_RECOVERY_REISSUE \ |
| | UBLK_F_UNPRIVILEGED_DEV \ |
| | UBLK_F_CMD_IOCTL_ENCODE \ |
| | UBLK_F_USER_COPY \ |
| | UBLK_F_ZONED) |
| |
| /* All UBLK_PARAM_TYPE_* should be included here */ |
| #define UBLK_PARAM_TYPE_ALL \ |
| (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD | \ |
| UBLK_PARAM_TYPE_DEVT | UBLK_PARAM_TYPE_ZONED) |
| |
| struct ublk_rq_data { |
| struct llist_node node; |
| |
| struct kref ref; |
| __u64 sector; |
| __u32 operation; |
| __u32 nr_zones; |
| }; |
| |
| struct ublk_uring_cmd_pdu { |
| struct ublk_queue *ubq; |
| u16 tag; |
| }; |
| |
| /* |
| * io command is active: sqe cmd is received, and its cqe isn't done |
| * |
| * If the flag is set, the io command is owned by ublk driver, and waited |
| * for incoming blk-mq request from the ublk block device. |
| * |
| * If the flag is cleared, the io command will be completed, and owned by |
| * ublk server. |
| */ |
| #define UBLK_IO_FLAG_ACTIVE 0x01 |
| |
| /* |
| * IO command is completed via cqe, and it is being handled by ublksrv, and |
| * not committed yet |
| * |
| * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for |
| * cross verification |
| */ |
| #define UBLK_IO_FLAG_OWNED_BY_SRV 0x02 |
| |
| /* |
| * IO command is aborted, so this flag is set in case of |
| * !UBLK_IO_FLAG_ACTIVE. |
| * |
| * After this flag is observed, any pending or new incoming request |
| * associated with this io command will be failed immediately |
| */ |
| #define UBLK_IO_FLAG_ABORTED 0x04 |
| |
| /* |
| * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires |
| * get data buffer address from ublksrv. |
| * |
| * Then, bio data could be copied into this data buffer for a WRITE request |
| * after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset. |
| */ |
| #define UBLK_IO_FLAG_NEED_GET_DATA 0x08 |
| |
| /* atomic RW with ubq->cancel_lock */ |
| #define UBLK_IO_FLAG_CANCELED 0x80000000 |
| |
| struct ublk_io { |
| /* userspace buffer address from io cmd */ |
| __u64 addr; |
| unsigned int flags; |
| int res; |
| |
| struct io_uring_cmd *cmd; |
| }; |
| |
| struct ublk_queue { |
| int q_id; |
| int q_depth; |
| |
| unsigned long flags; |
| struct task_struct *ubq_daemon; |
| char *io_cmd_buf; |
| |
| struct llist_head io_cmds; |
| |
| unsigned long io_addr; /* mapped vm address */ |
| unsigned int max_io_sz; |
| bool force_abort; |
| bool timeout; |
| bool canceling; |
| unsigned short nr_io_ready; /* how many ios setup */ |
| spinlock_t cancel_lock; |
| struct ublk_device *dev; |
| struct ublk_io ios[]; |
| }; |
| |
| struct ublk_device { |
| struct gendisk *ub_disk; |
| |
| char *__queues; |
| |
| unsigned int queue_size; |
| struct ublksrv_ctrl_dev_info dev_info; |
| |
| struct blk_mq_tag_set tag_set; |
| |
| struct cdev cdev; |
| struct device cdev_dev; |
| |
| #define UB_STATE_OPEN 0 |
| #define UB_STATE_USED 1 |
| #define UB_STATE_DELETED 2 |
| unsigned long state; |
| int ub_number; |
| |
| struct mutex mutex; |
| |
| spinlock_t lock; |
| struct mm_struct *mm; |
| |
| struct ublk_params params; |
| |
| struct completion completion; |
| unsigned int nr_queues_ready; |
| unsigned int nr_privileged_daemon; |
| |
| struct work_struct quiesce_work; |
| struct work_struct stop_work; |
| }; |
| |
| /* header of ublk_params */ |
| struct ublk_params_header { |
| __u32 len; |
| __u32 types; |
| }; |
| |
| static bool ublk_abort_requests(struct ublk_device *ub, struct ublk_queue *ubq); |
| |
| static inline unsigned int ublk_req_build_flags(struct request *req); |
| static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq, |
| int tag); |
| static inline bool ublk_dev_is_user_copy(const struct ublk_device *ub) |
| { |
| return ub->dev_info.flags & UBLK_F_USER_COPY; |
| } |
| |
| static inline bool ublk_dev_is_zoned(const struct ublk_device *ub) |
| { |
| return ub->dev_info.flags & UBLK_F_ZONED; |
| } |
| |
| static inline bool ublk_queue_is_zoned(struct ublk_queue *ubq) |
| { |
| return ubq->flags & UBLK_F_ZONED; |
| } |
| |
| #ifdef CONFIG_BLK_DEV_ZONED |
| |
| static int ublk_get_nr_zones(const struct ublk_device *ub) |
| { |
| const struct ublk_param_basic *p = &ub->params.basic; |
| |
| /* Zone size is a power of 2 */ |
| return p->dev_sectors >> ilog2(p->chunk_sectors); |
| } |
| |
| static int ublk_revalidate_disk_zones(struct ublk_device *ub) |
| { |
| return blk_revalidate_disk_zones(ub->ub_disk); |
| } |
| |
| static int ublk_dev_param_zoned_validate(const struct ublk_device *ub) |
| { |
| const struct ublk_param_zoned *p = &ub->params.zoned; |
| int nr_zones; |
| |
| if (!ublk_dev_is_zoned(ub)) |
| return -EINVAL; |
| |
| if (!p->max_zone_append_sectors) |
| return -EINVAL; |
| |
| nr_zones = ublk_get_nr_zones(ub); |
| |
| if (p->max_active_zones > nr_zones) |
| return -EINVAL; |
| |
| if (p->max_open_zones > nr_zones) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static void ublk_dev_param_zoned_apply(struct ublk_device *ub) |
| { |
| ub->ub_disk->nr_zones = ublk_get_nr_zones(ub); |
| } |
| |
| /* Based on virtblk_alloc_report_buffer */ |
| static void *ublk_alloc_report_buffer(struct ublk_device *ublk, |
| unsigned int nr_zones, size_t *buflen) |
| { |
| struct request_queue *q = ublk->ub_disk->queue; |
| size_t bufsize; |
| void *buf; |
| |
| nr_zones = min_t(unsigned int, nr_zones, |
| ublk->ub_disk->nr_zones); |
| |
| bufsize = nr_zones * sizeof(struct blk_zone); |
| bufsize = |
| min_t(size_t, bufsize, queue_max_hw_sectors(q) << SECTOR_SHIFT); |
| |
| while (bufsize >= sizeof(struct blk_zone)) { |
| buf = kvmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); |
| if (buf) { |
| *buflen = bufsize; |
| return buf; |
| } |
| bufsize >>= 1; |
| } |
| |
| *buflen = 0; |
| return NULL; |
| } |
| |
| static int ublk_report_zones(struct gendisk *disk, sector_t sector, |
| unsigned int nr_zones, report_zones_cb cb, void *data) |
| { |
| struct ublk_device *ub = disk->private_data; |
| unsigned int zone_size_sectors = disk->queue->limits.chunk_sectors; |
| unsigned int first_zone = sector >> ilog2(zone_size_sectors); |
| unsigned int done_zones = 0; |
| unsigned int max_zones_per_request; |
| int ret; |
| struct blk_zone *buffer; |
| size_t buffer_length; |
| |
| nr_zones = min_t(unsigned int, ub->ub_disk->nr_zones - first_zone, |
| nr_zones); |
| |
| buffer = ublk_alloc_report_buffer(ub, nr_zones, &buffer_length); |
| if (!buffer) |
| return -ENOMEM; |
| |
| max_zones_per_request = buffer_length / sizeof(struct blk_zone); |
| |
| while (done_zones < nr_zones) { |
| unsigned int remaining_zones = nr_zones - done_zones; |
| unsigned int zones_in_request = |
| min_t(unsigned int, remaining_zones, max_zones_per_request); |
| struct request *req; |
| struct ublk_rq_data *pdu; |
| blk_status_t status; |
| |
| memset(buffer, 0, buffer_length); |
| |
| req = blk_mq_alloc_request(disk->queue, REQ_OP_DRV_IN, 0); |
| if (IS_ERR(req)) { |
| ret = PTR_ERR(req); |
| goto out; |
| } |
| |
| pdu = blk_mq_rq_to_pdu(req); |
| pdu->operation = UBLK_IO_OP_REPORT_ZONES; |
| pdu->sector = sector; |
| pdu->nr_zones = zones_in_request; |
| |
| ret = blk_rq_map_kern(disk->queue, req, buffer, buffer_length, |
| GFP_KERNEL); |
| if (ret) { |
| blk_mq_free_request(req); |
| goto out; |
| } |
| |
| status = blk_execute_rq(req, 0); |
| ret = blk_status_to_errno(status); |
| blk_mq_free_request(req); |
| if (ret) |
| goto out; |
| |
| for (unsigned int i = 0; i < zones_in_request; i++) { |
| struct blk_zone *zone = buffer + i; |
| |
| /* A zero length zone means no more zones in this response */ |
| if (!zone->len) |
| break; |
| |
| ret = cb(zone, i, data); |
| if (ret) |
| goto out; |
| |
| done_zones++; |
| sector += zone_size_sectors; |
| |
| } |
| } |
| |
| ret = done_zones; |
| |
| out: |
| kvfree(buffer); |
| return ret; |
| } |
| |
| static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq, |
| struct request *req) |
| { |
| struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag); |
| struct ublk_io *io = &ubq->ios[req->tag]; |
| struct ublk_rq_data *pdu = blk_mq_rq_to_pdu(req); |
| u32 ublk_op; |
| |
| switch (req_op(req)) { |
| case REQ_OP_ZONE_OPEN: |
| ublk_op = UBLK_IO_OP_ZONE_OPEN; |
| break; |
| case REQ_OP_ZONE_CLOSE: |
| ublk_op = UBLK_IO_OP_ZONE_CLOSE; |
| break; |
| case REQ_OP_ZONE_FINISH: |
| ublk_op = UBLK_IO_OP_ZONE_FINISH; |
| break; |
| case REQ_OP_ZONE_RESET: |
| ublk_op = UBLK_IO_OP_ZONE_RESET; |
| break; |
| case REQ_OP_ZONE_APPEND: |
| ublk_op = UBLK_IO_OP_ZONE_APPEND; |
| break; |
| case REQ_OP_ZONE_RESET_ALL: |
| ublk_op = UBLK_IO_OP_ZONE_RESET_ALL; |
| break; |
| case REQ_OP_DRV_IN: |
| ublk_op = pdu->operation; |
| switch (ublk_op) { |
| case UBLK_IO_OP_REPORT_ZONES: |
| iod->op_flags = ublk_op | ublk_req_build_flags(req); |
| iod->nr_zones = pdu->nr_zones; |
| iod->start_sector = pdu->sector; |
| return BLK_STS_OK; |
| default: |
| return BLK_STS_IOERR; |
| } |
| case REQ_OP_DRV_OUT: |
| /* We do not support drv_out */ |
| return BLK_STS_NOTSUPP; |
| default: |
| return BLK_STS_IOERR; |
| } |
| |
| iod->op_flags = ublk_op | ublk_req_build_flags(req); |
| iod->nr_sectors = blk_rq_sectors(req); |
| iod->start_sector = blk_rq_pos(req); |
| iod->addr = io->addr; |
| |
| return BLK_STS_OK; |
| } |
| |
| #else |
| |
| #define ublk_report_zones (NULL) |
| |
| static int ublk_dev_param_zoned_validate(const struct ublk_device *ub) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static void ublk_dev_param_zoned_apply(struct ublk_device *ub) |
| { |
| } |
| |
| static int ublk_revalidate_disk_zones(struct ublk_device *ub) |
| { |
| return 0; |
| } |
| |
| static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq, |
| struct request *req) |
| { |
| return BLK_STS_NOTSUPP; |
| } |
| |
| #endif |
| |
| static inline void __ublk_complete_rq(struct request *req); |
| static void ublk_complete_rq(struct kref *ref); |
| |
| static dev_t ublk_chr_devt; |
| static const struct class ublk_chr_class = { |
| .name = "ublk-char", |
| }; |
| |
| static DEFINE_IDR(ublk_index_idr); |
| static DEFINE_SPINLOCK(ublk_idr_lock); |
| static wait_queue_head_t ublk_idr_wq; /* wait until one idr is freed */ |
| |
| static DEFINE_MUTEX(ublk_ctl_mutex); |
| |
| /* |
| * Max ublk devices allowed to add |
| * |
| * It can be extended to one per-user limit in future or even controlled |
| * by cgroup. |
| */ |
| #define UBLK_MAX_UBLKS UBLK_MINORS |
| static unsigned int ublks_max = 64; |
| static unsigned int ublks_added; /* protected by ublk_ctl_mutex */ |
| |
| static struct miscdevice ublk_misc; |
| |
| static inline unsigned ublk_pos_to_hwq(loff_t pos) |
| { |
| return ((pos - UBLKSRV_IO_BUF_OFFSET) >> UBLK_QID_OFF) & |
| UBLK_QID_BITS_MASK; |
| } |
| |
| static inline unsigned ublk_pos_to_buf_off(loff_t pos) |
| { |
| return (pos - UBLKSRV_IO_BUF_OFFSET) & UBLK_IO_BUF_BITS_MASK; |
| } |
| |
| static inline unsigned ublk_pos_to_tag(loff_t pos) |
| { |
| return ((pos - UBLKSRV_IO_BUF_OFFSET) >> UBLK_TAG_OFF) & |
| UBLK_TAG_BITS_MASK; |
| } |
| |
| static void ublk_dev_param_basic_apply(struct ublk_device *ub) |
| { |
| const struct ublk_param_basic *p = &ub->params.basic; |
| |
| if (p->attrs & UBLK_ATTR_READ_ONLY) |
| set_disk_ro(ub->ub_disk, true); |
| |
| set_capacity(ub->ub_disk, p->dev_sectors); |
| } |
| |
| static int ublk_validate_params(const struct ublk_device *ub) |
| { |
| /* basic param is the only one which must be set */ |
| if (ub->params.types & UBLK_PARAM_TYPE_BASIC) { |
| const struct ublk_param_basic *p = &ub->params.basic; |
| |
| if (p->logical_bs_shift > PAGE_SHIFT || p->logical_bs_shift < 9) |
| return -EINVAL; |
| |
| if (p->logical_bs_shift > p->physical_bs_shift) |
| return -EINVAL; |
| |
| if (p->max_sectors > (ub->dev_info.max_io_buf_bytes >> 9)) |
| return -EINVAL; |
| |
| if (ublk_dev_is_zoned(ub) && !p->chunk_sectors) |
| return -EINVAL; |
| } else |
| return -EINVAL; |
| |
| if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) { |
| const struct ublk_param_discard *p = &ub->params.discard; |
| |
| /* So far, only support single segment discard */ |
| if (p->max_discard_sectors && p->max_discard_segments != 1) |
| return -EINVAL; |
| |
| if (!p->discard_granularity) |
| return -EINVAL; |
| } |
| |
| /* dev_t is read-only */ |
| if (ub->params.types & UBLK_PARAM_TYPE_DEVT) |
| return -EINVAL; |
| |
| if (ub->params.types & UBLK_PARAM_TYPE_ZONED) |
| return ublk_dev_param_zoned_validate(ub); |
| else if (ublk_dev_is_zoned(ub)) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static void ublk_apply_params(struct ublk_device *ub) |
| { |
| ublk_dev_param_basic_apply(ub); |
| |
| if (ub->params.types & UBLK_PARAM_TYPE_ZONED) |
| ublk_dev_param_zoned_apply(ub); |
| } |
| |
| static inline bool ublk_support_user_copy(const struct ublk_queue *ubq) |
| { |
| return ubq->flags & UBLK_F_USER_COPY; |
| } |
| |
| static inline bool ublk_need_req_ref(const struct ublk_queue *ubq) |
| { |
| /* |
| * read()/write() is involved in user copy, so request reference |
| * has to be grabbed |
| */ |
| return ublk_support_user_copy(ubq); |
| } |
| |
| static inline void ublk_init_req_ref(const struct ublk_queue *ubq, |
| struct request *req) |
| { |
| if (ublk_need_req_ref(ubq)) { |
| struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); |
| |
| kref_init(&data->ref); |
| } |
| } |
| |
| static inline bool ublk_get_req_ref(const struct ublk_queue *ubq, |
| struct request *req) |
| { |
| if (ublk_need_req_ref(ubq)) { |
| struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); |
| |
| return kref_get_unless_zero(&data->ref); |
| } |
| |
| return true; |
| } |
| |
| static inline void ublk_put_req_ref(const struct ublk_queue *ubq, |
| struct request *req) |
| { |
| if (ublk_need_req_ref(ubq)) { |
| struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); |
| |
| kref_put(&data->ref, ublk_complete_rq); |
| } else { |
| __ublk_complete_rq(req); |
| } |
| } |
| |
| static inline bool ublk_need_get_data(const struct ublk_queue *ubq) |
| { |
| return ubq->flags & UBLK_F_NEED_GET_DATA; |
| } |
| |
| /* Called in slow path only, keep it noinline for trace purpose */ |
| static noinline struct ublk_device *ublk_get_device(struct ublk_device *ub) |
| { |
| if (kobject_get_unless_zero(&ub->cdev_dev.kobj)) |
| return ub; |
| return NULL; |
| } |
| |
| /* Called in slow path only, keep it noinline for trace purpose */ |
| static noinline void ublk_put_device(struct ublk_device *ub) |
| { |
| put_device(&ub->cdev_dev); |
| } |
| |
| static inline struct ublk_queue *ublk_get_queue(struct ublk_device *dev, |
| int qid) |
| { |
| return (struct ublk_queue *)&(dev->__queues[qid * dev->queue_size]); |
| } |
| |
| static inline bool ublk_rq_has_data(const struct request *rq) |
| { |
| return bio_has_data(rq->bio); |
| } |
| |
| static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq, |
| int tag) |
| { |
| return (struct ublksrv_io_desc *) |
| &(ubq->io_cmd_buf[tag * sizeof(struct ublksrv_io_desc)]); |
| } |
| |
| static inline char *ublk_queue_cmd_buf(struct ublk_device *ub, int q_id) |
| { |
| return ublk_get_queue(ub, q_id)->io_cmd_buf; |
| } |
| |
| static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) |
| { |
| struct ublk_queue *ubq = ublk_get_queue(ub, q_id); |
| |
| return round_up(ubq->q_depth * sizeof(struct ublksrv_io_desc), |
| PAGE_SIZE); |
| } |
| |
| static inline bool ublk_queue_can_use_recovery_reissue( |
| struct ublk_queue *ubq) |
| { |
| return (ubq->flags & UBLK_F_USER_RECOVERY) && |
| (ubq->flags & UBLK_F_USER_RECOVERY_REISSUE); |
| } |
| |
| static inline bool ublk_queue_can_use_recovery( |
| struct ublk_queue *ubq) |
| { |
| return ubq->flags & UBLK_F_USER_RECOVERY; |
| } |
| |
| static inline bool ublk_can_use_recovery(struct ublk_device *ub) |
| { |
| return ub->dev_info.flags & UBLK_F_USER_RECOVERY; |
| } |
| |
| static void ublk_free_disk(struct gendisk *disk) |
| { |
| struct ublk_device *ub = disk->private_data; |
| |
| clear_bit(UB_STATE_USED, &ub->state); |
| ublk_put_device(ub); |
| } |
| |
| static void ublk_store_owner_uid_gid(unsigned int *owner_uid, |
| unsigned int *owner_gid) |
| { |
| kuid_t uid; |
| kgid_t gid; |
| |
| current_uid_gid(&uid, &gid); |
| |
| *owner_uid = from_kuid(&init_user_ns, uid); |
| *owner_gid = from_kgid(&init_user_ns, gid); |
| } |
| |
| static int ublk_open(struct gendisk *disk, blk_mode_t mode) |
| { |
| struct ublk_device *ub = disk->private_data; |
| |
| if (capable(CAP_SYS_ADMIN)) |
| return 0; |
| |
| /* |
| * If it is one unprivileged device, only owner can open |
| * the disk. Otherwise it could be one trap made by one |
| * evil user who grants this disk's privileges to other |
| * users deliberately. |
| * |
| * This way is reasonable too given anyone can create |
| * unprivileged device, and no need other's grant. |
| */ |
| if (ub->dev_info.flags & UBLK_F_UNPRIVILEGED_DEV) { |
| unsigned int curr_uid, curr_gid; |
| |
| ublk_store_owner_uid_gid(&curr_uid, &curr_gid); |
| |
| if (curr_uid != ub->dev_info.owner_uid || curr_gid != |
| ub->dev_info.owner_gid) |
| return -EPERM; |
| } |
| |
| return 0; |
| } |
| |
| static const struct block_device_operations ub_fops = { |
| .owner = THIS_MODULE, |
| .open = ublk_open, |
| .free_disk = ublk_free_disk, |
| .report_zones = ublk_report_zones, |
| }; |
| |
| #define UBLK_MAX_PIN_PAGES 32 |
| |
| struct ublk_io_iter { |
| struct page *pages[UBLK_MAX_PIN_PAGES]; |
| struct bio *bio; |
| struct bvec_iter iter; |
| }; |
| |
| /* return how many pages are copied */ |
| static void ublk_copy_io_pages(struct ublk_io_iter *data, |
| size_t total, size_t pg_off, int dir) |
| { |
| unsigned done = 0; |
| unsigned pg_idx = 0; |
| |
| while (done < total) { |
| struct bio_vec bv = bio_iter_iovec(data->bio, data->iter); |
| unsigned int bytes = min3(bv.bv_len, (unsigned)total - done, |
| (unsigned)(PAGE_SIZE - pg_off)); |
| void *bv_buf = bvec_kmap_local(&bv); |
| void *pg_buf = kmap_local_page(data->pages[pg_idx]); |
| |
| if (dir == ITER_DEST) |
| memcpy(pg_buf + pg_off, bv_buf, bytes); |
| else |
| memcpy(bv_buf, pg_buf + pg_off, bytes); |
| |
| kunmap_local(pg_buf); |
| kunmap_local(bv_buf); |
| |
| /* advance page array */ |
| pg_off += bytes; |
| if (pg_off == PAGE_SIZE) { |
| pg_idx += 1; |
| pg_off = 0; |
| } |
| |
| done += bytes; |
| |
| /* advance bio */ |
| bio_advance_iter_single(data->bio, &data->iter, bytes); |
| if (!data->iter.bi_size) { |
| data->bio = data->bio->bi_next; |
| if (data->bio == NULL) |
| break; |
| data->iter = data->bio->bi_iter; |
| } |
| } |
| } |
| |
| static bool ublk_advance_io_iter(const struct request *req, |
| struct ublk_io_iter *iter, unsigned int offset) |
| { |
| struct bio *bio = req->bio; |
| |
| for_each_bio(bio) { |
| if (bio->bi_iter.bi_size > offset) { |
| iter->bio = bio; |
| iter->iter = bio->bi_iter; |
| bio_advance_iter(iter->bio, &iter->iter, offset); |
| return true; |
| } |
| offset -= bio->bi_iter.bi_size; |
| } |
| return false; |
| } |
| |
| /* |
| * Copy data between request pages and io_iter, and 'offset' |
| * is the start point of linear offset of request. |
| */ |
| static size_t ublk_copy_user_pages(const struct request *req, |
| unsigned offset, struct iov_iter *uiter, int dir) |
| { |
| struct ublk_io_iter iter; |
| size_t done = 0; |
| |
| if (!ublk_advance_io_iter(req, &iter, offset)) |
| return 0; |
| |
| while (iov_iter_count(uiter) && iter.bio) { |
| unsigned nr_pages; |
| ssize_t len; |
| size_t off; |
| int i; |
| |
| len = iov_iter_get_pages2(uiter, iter.pages, |
| iov_iter_count(uiter), |
| UBLK_MAX_PIN_PAGES, &off); |
| if (len <= 0) |
| return done; |
| |
| ublk_copy_io_pages(&iter, len, off, dir); |
| nr_pages = DIV_ROUND_UP(len + off, PAGE_SIZE); |
| for (i = 0; i < nr_pages; i++) { |
| if (dir == ITER_DEST) |
| set_page_dirty(iter.pages[i]); |
| put_page(iter.pages[i]); |
| } |
| done += len; |
| } |
| |
| return done; |
| } |
| |
| static inline bool ublk_need_map_req(const struct request *req) |
| { |
| return ublk_rq_has_data(req) && req_op(req) == REQ_OP_WRITE; |
| } |
| |
| static inline bool ublk_need_unmap_req(const struct request *req) |
| { |
| return ublk_rq_has_data(req) && |
| (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_DRV_IN); |
| } |
| |
| static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req, |
| struct ublk_io *io) |
| { |
| const unsigned int rq_bytes = blk_rq_bytes(req); |
| |
| if (ublk_support_user_copy(ubq)) |
| return rq_bytes; |
| |
| /* |
| * no zero copy, we delay copy WRITE request data into ublksrv |
| * context and the big benefit is that pinning pages in current |
| * context is pretty fast, see ublk_pin_user_pages |
| */ |
| if (ublk_need_map_req(req)) { |
| struct iov_iter iter; |
| const int dir = ITER_DEST; |
| |
| import_ubuf(dir, u64_to_user_ptr(io->addr), rq_bytes, &iter); |
| return ublk_copy_user_pages(req, 0, &iter, dir); |
| } |
| return rq_bytes; |
| } |
| |
| static int ublk_unmap_io(const struct ublk_queue *ubq, |
| const struct request *req, |
| struct ublk_io *io) |
| { |
| const unsigned int rq_bytes = blk_rq_bytes(req); |
| |
| if (ublk_support_user_copy(ubq)) |
| return rq_bytes; |
| |
| if (ublk_need_unmap_req(req)) { |
| struct iov_iter iter; |
| const int dir = ITER_SOURCE; |
| |
| WARN_ON_ONCE(io->res > rq_bytes); |
| |
| import_ubuf(dir, u64_to_user_ptr(io->addr), io->res, &iter); |
| return ublk_copy_user_pages(req, 0, &iter, dir); |
| } |
| return rq_bytes; |
| } |
| |
| static inline unsigned int ublk_req_build_flags(struct request *req) |
| { |
| unsigned flags = 0; |
| |
| if (req->cmd_flags & REQ_FAILFAST_DEV) |
| flags |= UBLK_IO_F_FAILFAST_DEV; |
| |
| if (req->cmd_flags & REQ_FAILFAST_TRANSPORT) |
| flags |= UBLK_IO_F_FAILFAST_TRANSPORT; |
| |
| if (req->cmd_flags & REQ_FAILFAST_DRIVER) |
| flags |= UBLK_IO_F_FAILFAST_DRIVER; |
| |
| if (req->cmd_flags & REQ_META) |
| flags |= UBLK_IO_F_META; |
| |
| if (req->cmd_flags & REQ_FUA) |
| flags |= UBLK_IO_F_FUA; |
| |
| if (req->cmd_flags & REQ_NOUNMAP) |
| flags |= UBLK_IO_F_NOUNMAP; |
| |
| if (req->cmd_flags & REQ_SWAP) |
| flags |= UBLK_IO_F_SWAP; |
| |
| return flags; |
| } |
| |
| static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req) |
| { |
| struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag); |
| struct ublk_io *io = &ubq->ios[req->tag]; |
| enum req_op op = req_op(req); |
| u32 ublk_op; |
| |
| if (!ublk_queue_is_zoned(ubq) && |
| (op_is_zone_mgmt(op) || op == REQ_OP_ZONE_APPEND)) |
| return BLK_STS_IOERR; |
| |
| switch (req_op(req)) { |
| case REQ_OP_READ: |
| ublk_op = UBLK_IO_OP_READ; |
| break; |
| case REQ_OP_WRITE: |
| ublk_op = UBLK_IO_OP_WRITE; |
| break; |
| case REQ_OP_FLUSH: |
| ublk_op = UBLK_IO_OP_FLUSH; |
| break; |
| case REQ_OP_DISCARD: |
| ublk_op = UBLK_IO_OP_DISCARD; |
| break; |
| case REQ_OP_WRITE_ZEROES: |
| ublk_op = UBLK_IO_OP_WRITE_ZEROES; |
| break; |
| default: |
| if (ublk_queue_is_zoned(ubq)) |
| return ublk_setup_iod_zoned(ubq, req); |
| return BLK_STS_IOERR; |
| } |
| |
| /* need to translate since kernel may change */ |
| iod->op_flags = ublk_op | ublk_req_build_flags(req); |
| iod->nr_sectors = blk_rq_sectors(req); |
| iod->start_sector = blk_rq_pos(req); |
| iod->addr = io->addr; |
| |
| return BLK_STS_OK; |
| } |
| |
| static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu( |
| struct io_uring_cmd *ioucmd) |
| { |
| return (struct ublk_uring_cmd_pdu *)&ioucmd->pdu; |
| } |
| |
| static inline bool ubq_daemon_is_dying(struct ublk_queue *ubq) |
| { |
| return ubq->ubq_daemon->flags & PF_EXITING; |
| } |
| |
| /* todo: handle partial completion */ |
| static inline void __ublk_complete_rq(struct request *req) |
| { |
| struct ublk_queue *ubq = req->mq_hctx->driver_data; |
| struct ublk_io *io = &ubq->ios[req->tag]; |
| unsigned int unmapped_bytes; |
| blk_status_t res = BLK_STS_OK; |
| |
| /* called from ublk_abort_queue() code path */ |
| if (io->flags & UBLK_IO_FLAG_ABORTED) { |
| res = BLK_STS_IOERR; |
| goto exit; |
| } |
| |
| /* failed read IO if nothing is read */ |
| if (!io->res && req_op(req) == REQ_OP_READ) |
| io->res = -EIO; |
| |
| if (io->res < 0) { |
| res = errno_to_blk_status(io->res); |
| goto exit; |
| } |
| |
| /* |
| * FLUSH, DISCARD or WRITE_ZEROES usually won't return bytes returned, so end them |
| * directly. |
| * |
| * Both the two needn't unmap. |
| */ |
| if (req_op(req) != REQ_OP_READ && req_op(req) != REQ_OP_WRITE && |
| req_op(req) != REQ_OP_DRV_IN) |
| goto exit; |
| |
| /* for READ request, writing data in iod->addr to rq buffers */ |
| unmapped_bytes = ublk_unmap_io(ubq, req, io); |
| |
| /* |
| * Extremely impossible since we got data filled in just before |
| * |
| * Re-read simply for this unlikely case. |
| */ |
| if (unlikely(unmapped_bytes < io->res)) |
| io->res = unmapped_bytes; |
| |
| if (blk_update_request(req, BLK_STS_OK, io->res)) |
| blk_mq_requeue_request(req, true); |
| else |
| __blk_mq_end_request(req, BLK_STS_OK); |
| |
| return; |
| exit: |
| blk_mq_end_request(req, res); |
| } |
| |
| static void ublk_complete_rq(struct kref *ref) |
| { |
| struct ublk_rq_data *data = container_of(ref, struct ublk_rq_data, |
| ref); |
| struct request *req = blk_mq_rq_from_pdu(data); |
| |
| __ublk_complete_rq(req); |
| } |
| |
| /* |
| * Since __ublk_rq_task_work always fails requests immediately during |
| * exiting, __ublk_fail_req() is only called from abort context during |
| * exiting. So lock is unnecessary. |
| * |
| * Also aborting may not be started yet, keep in mind that one failed |
| * request may be issued by block layer again. |
| */ |
| static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, |
| struct request *req) |
| { |
| WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); |
| |
| if (ublk_queue_can_use_recovery_reissue(ubq)) |
| blk_mq_requeue_request(req, false); |
| else |
| ublk_put_req_ref(ubq, req); |
| } |
| |
| static void ubq_complete_io_cmd(struct ublk_io *io, int res, |
| unsigned issue_flags) |
| { |
| /* mark this cmd owned by ublksrv */ |
| io->flags |= UBLK_IO_FLAG_OWNED_BY_SRV; |
| |
| /* |
| * clear ACTIVE since we are done with this sqe/cmd slot |
| * We can only accept io cmd in case of being not active. |
| */ |
| io->flags &= ~UBLK_IO_FLAG_ACTIVE; |
| |
| /* tell ublksrv one io request is coming */ |
| io_uring_cmd_done(io->cmd, res, 0, issue_flags); |
| } |
| |
| #define UBLK_REQUEUE_DELAY_MS 3 |
| |
| static inline void __ublk_abort_rq(struct ublk_queue *ubq, |
| struct request *rq) |
| { |
| /* We cannot process this rq so just requeue it. */ |
| if (ublk_queue_can_use_recovery(ubq)) |
| blk_mq_requeue_request(rq, false); |
| else |
| blk_mq_end_request(rq, BLK_STS_IOERR); |
| } |
| |
| static inline void __ublk_rq_task_work(struct request *req, |
| unsigned issue_flags) |
| { |
| struct ublk_queue *ubq = req->mq_hctx->driver_data; |
| int tag = req->tag; |
| struct ublk_io *io = &ubq->ios[tag]; |
| unsigned int mapped_bytes; |
| |
| pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n", |
| __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, |
| ublk_get_iod(ubq, req->tag)->addr); |
| |
| /* |
| * Task is exiting if either: |
| * |
| * (1) current != ubq_daemon. |
| * io_uring_cmd_complete_in_task() tries to run task_work |
| * in a workqueue if ubq_daemon(cmd's task) is PF_EXITING. |
| * |
| * (2) current->flags & PF_EXITING. |
| */ |
| if (unlikely(current != ubq->ubq_daemon || current->flags & PF_EXITING)) { |
| __ublk_abort_rq(ubq, req); |
| return; |
| } |
| |
| if (ublk_need_get_data(ubq) && ublk_need_map_req(req)) { |
| /* |
| * We have not handled UBLK_IO_NEED_GET_DATA command yet, |
| * so immepdately pass UBLK_IO_RES_NEED_GET_DATA to ublksrv |
| * and notify it. |
| */ |
| if (!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA)) { |
| io->flags |= UBLK_IO_FLAG_NEED_GET_DATA; |
| pr_devel("%s: need get data. op %d, qid %d tag %d io_flags %x\n", |
| __func__, io->cmd->cmd_op, ubq->q_id, |
| req->tag, io->flags); |
| ubq_complete_io_cmd(io, UBLK_IO_RES_NEED_GET_DATA, issue_flags); |
| return; |
| } |
| /* |
| * We have handled UBLK_IO_NEED_GET_DATA command, |
| * so clear UBLK_IO_FLAG_NEED_GET_DATA now and just |
| * do the copy work. |
| */ |
| io->flags &= ~UBLK_IO_FLAG_NEED_GET_DATA; |
| /* update iod->addr because ublksrv may have passed a new io buffer */ |
| ublk_get_iod(ubq, req->tag)->addr = io->addr; |
| pr_devel("%s: update iod->addr: op %d, qid %d tag %d io_flags %x addr %llx\n", |
| __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, |
| ublk_get_iod(ubq, req->tag)->addr); |
| } |
| |
| mapped_bytes = ublk_map_io(ubq, req, io); |
| |
| /* partially mapped, update io descriptor */ |
| if (unlikely(mapped_bytes != blk_rq_bytes(req))) { |
| /* |
| * Nothing mapped, retry until we succeed. |
| * |
| * We may never succeed in mapping any bytes here because |
| * of OOM. TODO: reserve one buffer with single page pinned |
| * for providing forward progress guarantee. |
| */ |
| if (unlikely(!mapped_bytes)) { |
| blk_mq_requeue_request(req, false); |
| blk_mq_delay_kick_requeue_list(req->q, |
| UBLK_REQUEUE_DELAY_MS); |
| return; |
| } |
| |
| ublk_get_iod(ubq, req->tag)->nr_sectors = |
| mapped_bytes >> 9; |
| } |
| |
| ublk_init_req_ref(ubq, req); |
| ubq_complete_io_cmd(io, UBLK_IO_RES_OK, issue_flags); |
| } |
| |
| static inline void ublk_forward_io_cmds(struct ublk_queue *ubq, |
| unsigned issue_flags) |
| { |
| struct llist_node *io_cmds = llist_del_all(&ubq->io_cmds); |
| struct ublk_rq_data *data, *tmp; |
| |
| io_cmds = llist_reverse_order(io_cmds); |
| llist_for_each_entry_safe(data, tmp, io_cmds, node) |
| __ublk_rq_task_work(blk_mq_rq_from_pdu(data), issue_flags); |
| } |
| |
| static void ublk_rq_task_work_cb(struct io_uring_cmd *cmd, unsigned issue_flags) |
| { |
| struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); |
| struct ublk_queue *ubq = pdu->ubq; |
| |
| ublk_forward_io_cmds(ubq, issue_flags); |
| } |
| |
| static void ublk_queue_cmd(struct ublk_queue *ubq, struct request *rq) |
| { |
| struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq); |
| |
| if (llist_add(&data->node, &ubq->io_cmds)) { |
| struct ublk_io *io = &ubq->ios[rq->tag]; |
| |
| io_uring_cmd_complete_in_task(io->cmd, ublk_rq_task_work_cb); |
| } |
| } |
| |
| static enum blk_eh_timer_return ublk_timeout(struct request *rq) |
| { |
| struct ublk_queue *ubq = rq->mq_hctx->driver_data; |
| unsigned int nr_inflight = 0; |
| int i; |
| |
| if (ubq->flags & UBLK_F_UNPRIVILEGED_DEV) { |
| if (!ubq->timeout) { |
| send_sig(SIGKILL, ubq->ubq_daemon, 0); |
| ubq->timeout = true; |
| } |
| |
| return BLK_EH_DONE; |
| } |
| |
| if (!ubq_daemon_is_dying(ubq)) |
| return BLK_EH_RESET_TIMER; |
| |
| for (i = 0; i < ubq->q_depth; i++) { |
| struct ublk_io *io = &ubq->ios[i]; |
| |
| if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) |
| nr_inflight++; |
| } |
| |
| /* cancelable uring_cmd can't help us if all commands are in-flight */ |
| if (nr_inflight == ubq->q_depth) { |
| struct ublk_device *ub = ubq->dev; |
| |
| if (ublk_abort_requests(ub, ubq)) { |
| if (ublk_can_use_recovery(ub)) |
| schedule_work(&ub->quiesce_work); |
| else |
| schedule_work(&ub->stop_work); |
| } |
| return BLK_EH_DONE; |
| } |
| |
| return BLK_EH_RESET_TIMER; |
| } |
| |
| static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, |
| const struct blk_mq_queue_data *bd) |
| { |
| struct ublk_queue *ubq = hctx->driver_data; |
| struct request *rq = bd->rq; |
| blk_status_t res; |
| |
| /* fill iod to slot in io cmd buffer */ |
| res = ublk_setup_iod(ubq, rq); |
| if (unlikely(res != BLK_STS_OK)) |
| return BLK_STS_IOERR; |
| |
| /* With recovery feature enabled, force_abort is set in |
| * ublk_stop_dev() before calling del_gendisk(). We have to |
| * abort all requeued and new rqs here to let del_gendisk() |
| * move on. Besides, we cannot not call io_uring_cmd_complete_in_task() |
| * to avoid UAF on io_uring ctx. |
| * |
| * Note: force_abort is guaranteed to be seen because it is set |
| * before request queue is unqiuesced. |
| */ |
| if (ublk_queue_can_use_recovery(ubq) && unlikely(ubq->force_abort)) |
| return BLK_STS_IOERR; |
| |
| if (unlikely(ubq->canceling)) { |
| __ublk_abort_rq(ubq, rq); |
| return BLK_STS_OK; |
| } |
| |
| blk_mq_start_request(bd->rq); |
| ublk_queue_cmd(ubq, rq); |
| |
| return BLK_STS_OK; |
| } |
| |
| static int ublk_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data, |
| unsigned int hctx_idx) |
| { |
| struct ublk_device *ub = driver_data; |
| struct ublk_queue *ubq = ublk_get_queue(ub, hctx->queue_num); |
| |
| hctx->driver_data = ubq; |
| return 0; |
| } |
| |
| static const struct blk_mq_ops ublk_mq_ops = { |
| .queue_rq = ublk_queue_rq, |
| .init_hctx = ublk_init_hctx, |
| .timeout = ublk_timeout, |
| }; |
| |
| static int ublk_ch_open(struct inode *inode, struct file *filp) |
| { |
| struct ublk_device *ub = container_of(inode->i_cdev, |
| struct ublk_device, cdev); |
| |
| if (test_and_set_bit(UB_STATE_OPEN, &ub->state)) |
| return -EBUSY; |
| filp->private_data = ub; |
| return 0; |
| } |
| |
| static int ublk_ch_release(struct inode *inode, struct file *filp) |
| { |
| struct ublk_device *ub = filp->private_data; |
| |
| clear_bit(UB_STATE_OPEN, &ub->state); |
| return 0; |
| } |
| |
| /* map pre-allocated per-queue cmd buffer to ublksrv daemon */ |
| static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma) |
| { |
| struct ublk_device *ub = filp->private_data; |
| size_t sz = vma->vm_end - vma->vm_start; |
| unsigned max_sz = UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc); |
| unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT; |
| int q_id, ret = 0; |
| |
| spin_lock(&ub->lock); |
| if (!ub->mm) |
| ub->mm = current->mm; |
| if (current->mm != ub->mm) |
| ret = -EINVAL; |
| spin_unlock(&ub->lock); |
| |
| if (ret) |
| return ret; |
| |
| if (vma->vm_flags & VM_WRITE) |
| return -EPERM; |
| |
| end = UBLKSRV_CMD_BUF_OFFSET + ub->dev_info.nr_hw_queues * max_sz; |
| if (phys_off < UBLKSRV_CMD_BUF_OFFSET || phys_off >= end) |
| return -EINVAL; |
| |
| q_id = (phys_off - UBLKSRV_CMD_BUF_OFFSET) / max_sz; |
| pr_devel("%s: qid %d, pid %d, addr %lx pg_off %lx sz %lu\n", |
| __func__, q_id, current->pid, vma->vm_start, |
| phys_off, (unsigned long)sz); |
| |
| if (sz != ublk_queue_cmd_buf_size(ub, q_id)) |
| return -EINVAL; |
| |
| pfn = virt_to_phys(ublk_queue_cmd_buf(ub, q_id)) >> PAGE_SHIFT; |
| return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); |
| } |
| |
| static void ublk_commit_completion(struct ublk_device *ub, |
| const struct ublksrv_io_cmd *ub_cmd) |
| { |
| u32 qid = ub_cmd->q_id, tag = ub_cmd->tag; |
| struct ublk_queue *ubq = ublk_get_queue(ub, qid); |
| struct ublk_io *io = &ubq->ios[tag]; |
| struct request *req; |
| |
| /* now this cmd slot is owned by nbd driver */ |
| io->flags &= ~UBLK_IO_FLAG_OWNED_BY_SRV; |
| io->res = ub_cmd->result; |
| |
| /* find the io request and complete */ |
| req = blk_mq_tag_to_rq(ub->tag_set.tags[qid], tag); |
| if (WARN_ON_ONCE(unlikely(!req))) |
| return; |
| |
| if (req_op(req) == REQ_OP_ZONE_APPEND) |
| req->__sector = ub_cmd->zone_append_lba; |
| |
| if (likely(!blk_should_fake_timeout(req->q))) |
| ublk_put_req_ref(ubq, req); |
| } |
| |
| /* |
| * Called from ubq_daemon context via cancel fn, meantime quiesce ublk |
| * blk-mq queue, so we are called exclusively with blk-mq and ubq_daemon |
| * context, so everything is serialized. |
| */ |
| static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) |
| { |
| int i; |
| |
| for (i = 0; i < ubq->q_depth; i++) { |
| struct ublk_io *io = &ubq->ios[i]; |
| |
| if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) { |
| struct request *rq; |
| |
| /* |
| * Either we fail the request or ublk_rq_task_work_fn |
| * will do it |
| */ |
| rq = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], i); |
| if (rq && blk_mq_request_started(rq)) { |
| io->flags |= UBLK_IO_FLAG_ABORTED; |
| __ublk_fail_req(ubq, io, rq); |
| } |
| } |
| } |
| } |
| |
| static bool ublk_abort_requests(struct ublk_device *ub, struct ublk_queue *ubq) |
| { |
| struct gendisk *disk; |
| |
| spin_lock(&ubq->cancel_lock); |
| if (ubq->canceling) { |
| spin_unlock(&ubq->cancel_lock); |
| return false; |
| } |
| ubq->canceling = true; |
| spin_unlock(&ubq->cancel_lock); |
| |
| spin_lock(&ub->lock); |
| disk = ub->ub_disk; |
| if (disk) |
| get_device(disk_to_dev(disk)); |
| spin_unlock(&ub->lock); |
| |
| /* Our disk has been dead */ |
| if (!disk) |
| return false; |
| |
| /* Now we are serialized with ublk_queue_rq() */ |
| blk_mq_quiesce_queue(disk->queue); |
| /* abort queue is for making forward progress */ |
| ublk_abort_queue(ub, ubq); |
| blk_mq_unquiesce_queue(disk->queue); |
| put_device(disk_to_dev(disk)); |
| |
| return true; |
| } |
| |
| static void ublk_cancel_cmd(struct ublk_queue *ubq, struct ublk_io *io, |
| unsigned int issue_flags) |
| { |
| bool done; |
| |
| if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) |
| return; |
| |
| spin_lock(&ubq->cancel_lock); |
| done = !!(io->flags & UBLK_IO_FLAG_CANCELED); |
| if (!done) |
| io->flags |= UBLK_IO_FLAG_CANCELED; |
| spin_unlock(&ubq->cancel_lock); |
| |
| if (!done) |
| io_uring_cmd_done(io->cmd, UBLK_IO_RES_ABORT, 0, issue_flags); |
| } |
| |
| /* |
| * The ublk char device won't be closed when calling cancel fn, so both |
| * ublk device and queue are guaranteed to be live |
| */ |
| static void ublk_uring_cmd_cancel_fn(struct io_uring_cmd *cmd, |
| unsigned int issue_flags) |
| { |
| struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); |
| struct ublk_queue *ubq = pdu->ubq; |
| struct task_struct *task; |
| struct ublk_device *ub; |
| bool need_schedule; |
| struct ublk_io *io; |
| |
| if (WARN_ON_ONCE(!ubq)) |
| return; |
| |
| if (WARN_ON_ONCE(pdu->tag >= ubq->q_depth)) |
| return; |
| |
| task = io_uring_cmd_get_task(cmd); |
| if (WARN_ON_ONCE(task && task != ubq->ubq_daemon)) |
| return; |
| |
| ub = ubq->dev; |
| need_schedule = ublk_abort_requests(ub, ubq); |
| |
| io = &ubq->ios[pdu->tag]; |
| WARN_ON_ONCE(io->cmd != cmd); |
| ublk_cancel_cmd(ubq, io, issue_flags); |
| |
| if (need_schedule) { |
| if (ublk_can_use_recovery(ub)) |
| schedule_work(&ub->quiesce_work); |
| else |
| schedule_work(&ub->stop_work); |
| } |
| } |
| |
| static inline bool ublk_queue_ready(struct ublk_queue *ubq) |
| { |
| return ubq->nr_io_ready == ubq->q_depth; |
| } |
| |
| static void ublk_cancel_queue(struct ublk_queue *ubq) |
| { |
| int i; |
| |
| for (i = 0; i < ubq->q_depth; i++) |
| ublk_cancel_cmd(ubq, &ubq->ios[i], IO_URING_F_UNLOCKED); |
| } |
| |
| /* Cancel all pending commands, must be called after del_gendisk() returns */ |
| static void ublk_cancel_dev(struct ublk_device *ub) |
| { |
| int i; |
| |
| for (i = 0; i < ub->dev_info.nr_hw_queues; i++) |
| ublk_cancel_queue(ublk_get_queue(ub, i)); |
| } |
| |
| static bool ublk_check_inflight_rq(struct request *rq, void *data) |
| { |
| bool *idle = data; |
| |
| if (blk_mq_request_started(rq)) { |
| *idle = false; |
| return false; |
| } |
| return true; |
| } |
| |
| static void ublk_wait_tagset_rqs_idle(struct ublk_device *ub) |
| { |
| bool idle; |
| |
| WARN_ON_ONCE(!blk_queue_quiesced(ub->ub_disk->queue)); |
| while (true) { |
| idle = true; |
| blk_mq_tagset_busy_iter(&ub->tag_set, |
| ublk_check_inflight_rq, &idle); |
| if (idle) |
| break; |
| msleep(UBLK_REQUEUE_DELAY_MS); |
| } |
| } |
| |
| static void __ublk_quiesce_dev(struct ublk_device *ub) |
| { |
| pr_devel("%s: quiesce ub: dev_id %d state %s\n", |
| __func__, ub->dev_info.dev_id, |
| ub->dev_info.state == UBLK_S_DEV_LIVE ? |
| "LIVE" : "QUIESCED"); |
| blk_mq_quiesce_queue(ub->ub_disk->queue); |
| ublk_wait_tagset_rqs_idle(ub); |
| ub->dev_info.state = UBLK_S_DEV_QUIESCED; |
| } |
| |
| static void ublk_quiesce_work_fn(struct work_struct *work) |
| { |
| struct ublk_device *ub = |
| container_of(work, struct ublk_device, quiesce_work); |
| |
| mutex_lock(&ub->mutex); |
| if (ub->dev_info.state != UBLK_S_DEV_LIVE) |
| goto unlock; |
| __ublk_quiesce_dev(ub); |
| unlock: |
| mutex_unlock(&ub->mutex); |
| ublk_cancel_dev(ub); |
| } |
| |
| static void ublk_unquiesce_dev(struct ublk_device *ub) |
| { |
| int i; |
| |
| pr_devel("%s: unquiesce ub: dev_id %d state %s\n", |
| __func__, ub->dev_info.dev_id, |
| ub->dev_info.state == UBLK_S_DEV_LIVE ? |
| "LIVE" : "QUIESCED"); |
| /* quiesce_work has run. We let requeued rqs be aborted |
| * before running fallback_wq. "force_abort" must be seen |
| * after request queue is unqiuesced. Then del_gendisk() |
| * can move on. |
| */ |
| for (i = 0; i < ub->dev_info.nr_hw_queues; i++) |
| ublk_get_queue(ub, i)->force_abort = true; |
| |
| blk_mq_unquiesce_queue(ub->ub_disk->queue); |
| /* We may have requeued some rqs in ublk_quiesce_queue() */ |
| blk_mq_kick_requeue_list(ub->ub_disk->queue); |
| } |
| |
| static void ublk_stop_dev(struct ublk_device *ub) |
| { |
| struct gendisk *disk; |
| |
| mutex_lock(&ub->mutex); |
| if (ub->dev_info.state == UBLK_S_DEV_DEAD) |
| goto unlock; |
| if (ublk_can_use_recovery(ub)) { |
| if (ub->dev_info.state == UBLK_S_DEV_LIVE) |
| __ublk_quiesce_dev(ub); |
| ublk_unquiesce_dev(ub); |
| } |
| del_gendisk(ub->ub_disk); |
| |
| /* Sync with ublk_abort_queue() by holding the lock */ |
| spin_lock(&ub->lock); |
| disk = ub->ub_disk; |
| ub->dev_info.state = UBLK_S_DEV_DEAD; |
| ub->dev_info.ublksrv_pid = -1; |
| ub->ub_disk = NULL; |
| spin_unlock(&ub->lock); |
| put_disk(disk); |
| unlock: |
| mutex_unlock(&ub->mutex); |
| ublk_cancel_dev(ub); |
| } |
| |
| /* device can only be started after all IOs are ready */ |
| static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq) |
| { |
| mutex_lock(&ub->mutex); |
| ubq->nr_io_ready++; |
| if (ublk_queue_ready(ubq)) { |
| ubq->ubq_daemon = current; |
| get_task_struct(ubq->ubq_daemon); |
| ub->nr_queues_ready++; |
| |
| if (capable(CAP_SYS_ADMIN)) |
| ub->nr_privileged_daemon++; |
| } |
| if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues) |
| complete_all(&ub->completion); |
| mutex_unlock(&ub->mutex); |
| } |
| |
| static void ublk_handle_need_get_data(struct ublk_device *ub, int q_id, |
| int tag) |
| { |
| struct ublk_queue *ubq = ublk_get_queue(ub, q_id); |
| struct request *req = blk_mq_tag_to_rq(ub->tag_set.tags[q_id], tag); |
| |
| ublk_queue_cmd(ubq, req); |
| } |
| |
| static inline int ublk_check_cmd_op(u32 cmd_op) |
| { |
| u32 ioc_type = _IOC_TYPE(cmd_op); |
| |
| if (!IS_ENABLED(CONFIG_BLKDEV_UBLK_LEGACY_OPCODES) && ioc_type != 'u') |
| return -EOPNOTSUPP; |
| |
| if (ioc_type != 'u' && ioc_type != 0) |
| return -EOPNOTSUPP; |
| |
| return 0; |
| } |
| |
| static inline void ublk_fill_io_cmd(struct ublk_io *io, |
| struct io_uring_cmd *cmd, unsigned long buf_addr) |
| { |
| io->cmd = cmd; |
| io->flags |= UBLK_IO_FLAG_ACTIVE; |
| io->addr = buf_addr; |
| } |
| |
| static inline void ublk_prep_cancel(struct io_uring_cmd *cmd, |
| unsigned int issue_flags, |
| struct ublk_queue *ubq, unsigned int tag) |
| { |
| struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); |
| |
| /* |
| * Safe to refer to @ubq since ublk_queue won't be died until its |
| * commands are completed |
| */ |
| pdu->ubq = ubq; |
| pdu->tag = tag; |
| io_uring_cmd_mark_cancelable(cmd, issue_flags); |
| } |
| |
| static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd, |
| unsigned int issue_flags, |
| const struct ublksrv_io_cmd *ub_cmd) |
| { |
| struct ublk_device *ub = cmd->file->private_data; |
| struct ublk_queue *ubq; |
| struct ublk_io *io; |
| u32 cmd_op = cmd->cmd_op; |
| unsigned tag = ub_cmd->tag; |
| int ret = -EINVAL; |
| struct request *req; |
| |
| pr_devel("%s: received: cmd op %d queue %d tag %d result %d\n", |
| __func__, cmd->cmd_op, ub_cmd->q_id, tag, |
| ub_cmd->result); |
| |
| if (ub_cmd->q_id >= ub->dev_info.nr_hw_queues) |
| goto out; |
| |
| ubq = ublk_get_queue(ub, ub_cmd->q_id); |
| if (!ubq || ub_cmd->q_id != ubq->q_id) |
| goto out; |
| |
| if (ubq->ubq_daemon && ubq->ubq_daemon != current) |
| goto out; |
| |
| if (tag >= ubq->q_depth) |
| goto out; |
| |
| io = &ubq->ios[tag]; |
| |
| /* there is pending io cmd, something must be wrong */ |
| if (io->flags & UBLK_IO_FLAG_ACTIVE) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| /* |
| * ensure that the user issues UBLK_IO_NEED_GET_DATA |
| * iff the driver have set the UBLK_IO_FLAG_NEED_GET_DATA. |
| */ |
| if ((!!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA)) |
| ^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA)) |
| goto out; |
| |
| ret = ublk_check_cmd_op(cmd_op); |
| if (ret) |
| goto out; |
| |
| ret = -EINVAL; |
| switch (_IOC_NR(cmd_op)) { |
| case UBLK_IO_FETCH_REQ: |
| /* UBLK_IO_FETCH_REQ is only allowed before queue is setup */ |
| if (ublk_queue_ready(ubq)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| /* |
| * The io is being handled by server, so COMMIT_RQ is expected |
| * instead of FETCH_REQ |
| */ |
| if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV) |
| goto out; |
| |
| if (!ublk_support_user_copy(ubq)) { |
| /* |
| * FETCH_RQ has to provide IO buffer if NEED GET |
| * DATA is not enabled |
| */ |
| if (!ub_cmd->addr && !ublk_need_get_data(ubq)) |
| goto out; |
| } else if (ub_cmd->addr) { |
| /* User copy requires addr to be unset */ |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| ublk_fill_io_cmd(io, cmd, ub_cmd->addr); |
| ublk_mark_io_ready(ub, ubq); |
| break; |
| case UBLK_IO_COMMIT_AND_FETCH_REQ: |
| req = blk_mq_tag_to_rq(ub->tag_set.tags[ub_cmd->q_id], tag); |
| |
| if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) |
| goto out; |
| |
| if (!ublk_support_user_copy(ubq)) { |
| /* |
| * COMMIT_AND_FETCH_REQ has to provide IO buffer if |
| * NEED GET DATA is not enabled or it is Read IO. |
| */ |
| if (!ub_cmd->addr && (!ublk_need_get_data(ubq) || |
| req_op(req) == REQ_OP_READ)) |
| goto out; |
| } else if (req_op(req) != REQ_OP_ZONE_APPEND && ub_cmd->addr) { |
| /* |
| * User copy requires addr to be unset when command is |
| * not zone append |
| */ |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| ublk_fill_io_cmd(io, cmd, ub_cmd->addr); |
| ublk_commit_completion(ub, ub_cmd); |
| break; |
| case UBLK_IO_NEED_GET_DATA: |
| if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) |
| goto out; |
| ublk_fill_io_cmd(io, cmd, ub_cmd->addr); |
| ublk_handle_need_get_data(ub, ub_cmd->q_id, ub_cmd->tag); |
| break; |
| default: |
| goto out; |
| } |
| ublk_prep_cancel(cmd, issue_flags, ubq, tag); |
| return -EIOCBQUEUED; |
| |
| out: |
| io_uring_cmd_done(cmd, ret, 0, issue_flags); |
| pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n", |
| __func__, cmd_op, tag, ret, io->flags); |
| return -EIOCBQUEUED; |
| } |
| |
| static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub, |
| struct ublk_queue *ubq, int tag, size_t offset) |
| { |
| struct request *req; |
| |
| if (!ublk_need_req_ref(ubq)) |
| return NULL; |
| |
| req = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], tag); |
| if (!req) |
| return NULL; |
| |
| if (!ublk_get_req_ref(ubq, req)) |
| return NULL; |
| |
| if (unlikely(!blk_mq_request_started(req) || req->tag != tag)) |
| goto fail_put; |
| |
| if (!ublk_rq_has_data(req)) |
| goto fail_put; |
| |
| if (offset > blk_rq_bytes(req)) |
| goto fail_put; |
| |
| return req; |
| fail_put: |
| ublk_put_req_ref(ubq, req); |
| return NULL; |
| } |
| |
| static inline int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd, |
| unsigned int issue_flags) |
| { |
| /* |
| * Not necessary for async retry, but let's keep it simple and always |
| * copy the values to avoid any potential reuse. |
| */ |
| const struct ublksrv_io_cmd *ub_src = io_uring_sqe_cmd(cmd->sqe); |
| const struct ublksrv_io_cmd ub_cmd = { |
| .q_id = READ_ONCE(ub_src->q_id), |
| .tag = READ_ONCE(ub_src->tag), |
| .result = READ_ONCE(ub_src->result), |
| .addr = READ_ONCE(ub_src->addr) |
| }; |
| |
| WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED); |
| |
| return __ublk_ch_uring_cmd(cmd, issue_flags, &ub_cmd); |
| } |
| |
| static void ublk_ch_uring_cmd_cb(struct io_uring_cmd *cmd, |
| unsigned int issue_flags) |
| { |
| ublk_ch_uring_cmd_local(cmd, issue_flags); |
| } |
| |
| static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) |
| { |
| if (unlikely(issue_flags & IO_URING_F_CANCEL)) { |
| ublk_uring_cmd_cancel_fn(cmd, issue_flags); |
| return 0; |
| } |
| |
| /* well-implemented server won't run into unlocked */ |
| if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) { |
| io_uring_cmd_complete_in_task(cmd, ublk_ch_uring_cmd_cb); |
| return -EIOCBQUEUED; |
| } |
| |
| return ublk_ch_uring_cmd_local(cmd, issue_flags); |
| } |
| |
| static inline bool ublk_check_ubuf_dir(const struct request *req, |
| int ubuf_dir) |
| { |
| /* copy ubuf to request pages */ |
| if ((req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_DRV_IN) && |
| ubuf_dir == ITER_SOURCE) |
| return true; |
| |
| /* copy request pages to ubuf */ |
| if ((req_op(req) == REQ_OP_WRITE || |
| req_op(req) == REQ_OP_ZONE_APPEND) && |
| ubuf_dir == ITER_DEST) |
| return true; |
| |
| return false; |
| } |
| |
| static struct request *ublk_check_and_get_req(struct kiocb *iocb, |
| struct iov_iter *iter, size_t *off, int dir) |
| { |
| struct ublk_device *ub = iocb->ki_filp->private_data; |
| struct ublk_queue *ubq; |
| struct request *req; |
| size_t buf_off; |
| u16 tag, q_id; |
| |
| if (!ub) |
| return ERR_PTR(-EACCES); |
| |
| if (!user_backed_iter(iter)) |
| return ERR_PTR(-EACCES); |
| |
| if (ub->dev_info.state == UBLK_S_DEV_DEAD) |
| return ERR_PTR(-EACCES); |
| |
| tag = ublk_pos_to_tag(iocb->ki_pos); |
| q_id = ublk_pos_to_hwq(iocb->ki_pos); |
| buf_off = ublk_pos_to_buf_off(iocb->ki_pos); |
| |
| if (q_id >= ub->dev_info.nr_hw_queues) |
| return ERR_PTR(-EINVAL); |
| |
| ubq = ublk_get_queue(ub, q_id); |
| if (!ubq) |
| return ERR_PTR(-EINVAL); |
| |
| if (tag >= ubq->q_depth) |
| return ERR_PTR(-EINVAL); |
| |
| req = __ublk_check_and_get_req(ub, ubq, tag, buf_off); |
| if (!req) |
| return ERR_PTR(-EINVAL); |
| |
| if (!req->mq_hctx || !req->mq_hctx->driver_data) |
| goto fail; |
| |
| if (!ublk_check_ubuf_dir(req, dir)) |
| goto fail; |
| |
| *off = buf_off; |
| return req; |
| fail: |
| ublk_put_req_ref(ubq, req); |
| return ERR_PTR(-EACCES); |
| } |
| |
| static ssize_t ublk_ch_read_iter(struct kiocb *iocb, struct iov_iter *to) |
| { |
| struct ublk_queue *ubq; |
| struct request *req; |
| size_t buf_off; |
| size_t ret; |
| |
| req = ublk_check_and_get_req(iocb, to, &buf_off, ITER_DEST); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| ret = ublk_copy_user_pages(req, buf_off, to, ITER_DEST); |
| ubq = req->mq_hctx->driver_data; |
| ublk_put_req_ref(ubq, req); |
| |
| return ret; |
| } |
| |
| static ssize_t ublk_ch_write_iter(struct kiocb *iocb, struct iov_iter *from) |
| { |
| struct ublk_queue *ubq; |
| struct request *req; |
| size_t buf_off; |
| size_t ret; |
| |
| req = ublk_check_and_get_req(iocb, from, &buf_off, ITER_SOURCE); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| ret = ublk_copy_user_pages(req, buf_off, from, ITER_SOURCE); |
| ubq = req->mq_hctx->driver_data; |
| ublk_put_req_ref(ubq, req); |
| |
| return ret; |
| } |
| |
| static const struct file_operations ublk_ch_fops = { |
| .owner = THIS_MODULE, |
| .open = ublk_ch_open, |
| .release = ublk_ch_release, |
| .llseek = no_llseek, |
| .read_iter = ublk_ch_read_iter, |
| .write_iter = ublk_ch_write_iter, |
| .uring_cmd = ublk_ch_uring_cmd, |
| .mmap = ublk_ch_mmap, |
| }; |
| |
| static void ublk_deinit_queue(struct ublk_device *ub, int q_id) |
| { |
| int size = ublk_queue_cmd_buf_size(ub, q_id); |
| struct ublk_queue *ubq = ublk_get_queue(ub, q_id); |
| |
| if (ubq->ubq_daemon) |
| put_task_struct(ubq->ubq_daemon); |
| if (ubq->io_cmd_buf) |
| free_pages((unsigned long)ubq->io_cmd_buf, get_order(size)); |
| } |
| |
| static int ublk_init_queue(struct ublk_device *ub, int q_id) |
| { |
| struct ublk_queue *ubq = ublk_get_queue(ub, q_id); |
| gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO; |
| void *ptr; |
| int size; |
| |
| spin_lock_init(&ubq->cancel_lock); |
| ubq->flags = ub->dev_info.flags; |
| ubq->q_id = q_id; |
| ubq->q_depth = ub->dev_info.queue_depth; |
| size = ublk_queue_cmd_buf_size(ub, q_id); |
| |
| ptr = (void *) __get_free_pages(gfp_flags, get_order(size)); |
| if (!ptr) |
| return -ENOMEM; |
| |
| ubq->io_cmd_buf = ptr; |
| ubq->dev = ub; |
| return 0; |
| } |
| |
| static void ublk_deinit_queues(struct ublk_device *ub) |
| { |
| int nr_queues = ub->dev_info.nr_hw_queues; |
| int i; |
| |
| if (!ub->__queues) |
| return; |
| |
| for (i = 0; i < nr_queues; i++) |
| ublk_deinit_queue(ub, i); |
| kfree(ub->__queues); |
| } |
| |
| static int ublk_init_queues(struct ublk_device *ub) |
| { |
| int nr_queues = ub->dev_info.nr_hw_queues; |
| int depth = ub->dev_info.queue_depth; |
| int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io); |
| int i, ret = -ENOMEM; |
| |
| ub->queue_size = ubq_size; |
| ub->__queues = kcalloc(nr_queues, ubq_size, GFP_KERNEL); |
| if (!ub->__queues) |
| return ret; |
| |
| for (i = 0; i < nr_queues; i++) { |
| if (ublk_init_queue(ub, i)) |
| goto fail; |
| } |
| |
| init_completion(&ub->completion); |
| return 0; |
| |
| fail: |
| ublk_deinit_queues(ub); |
| return ret; |
| } |
| |
| static int ublk_alloc_dev_number(struct ublk_device *ub, int idx) |
| { |
| int i = idx; |
| int err; |
| |
| spin_lock(&ublk_idr_lock); |
| /* allocate id, if @id >= 0, we're requesting that specific id */ |
| if (i >= 0) { |
| err = idr_alloc(&ublk_index_idr, ub, i, i + 1, GFP_NOWAIT); |
| if (err == -ENOSPC) |
| err = -EEXIST; |
| } else { |
| err = idr_alloc(&ublk_index_idr, ub, 0, UBLK_MAX_UBLKS, |
| GFP_NOWAIT); |
| } |
| spin_unlock(&ublk_idr_lock); |
| |
| if (err >= 0) |
| ub->ub_number = err; |
| |
| return err; |
| } |
| |
| static void ublk_free_dev_number(struct ublk_device *ub) |
| { |
| spin_lock(&ublk_idr_lock); |
| idr_remove(&ublk_index_idr, ub->ub_number); |
| wake_up_all(&ublk_idr_wq); |
| spin_unlock(&ublk_idr_lock); |
| } |
| |
| static void ublk_cdev_rel(struct device *dev) |
| { |
| struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev); |
| |
| blk_mq_free_tag_set(&ub->tag_set); |
| ublk_deinit_queues(ub); |
| ublk_free_dev_number(ub); |
| mutex_destroy(&ub->mutex); |
| kfree(ub); |
| } |
| |
| static int ublk_add_chdev(struct ublk_device *ub) |
| { |
| struct device *dev = &ub->cdev_dev; |
| int minor = ub->ub_number; |
| int ret; |
| |
| dev->parent = ublk_misc.this_device; |
| dev->devt = MKDEV(MAJOR(ublk_chr_devt), minor); |
| dev->class = &ublk_chr_class; |
| dev->release = ublk_cdev_rel; |
| device_initialize(dev); |
| |
| ret = dev_set_name(dev, "ublkc%d", minor); |
| if (ret) |
| goto fail; |
| |
| cdev_init(&ub->cdev, &ublk_ch_fops); |
| ret = cdev_device_add(&ub->cdev, dev); |
| if (ret) |
| goto fail; |
| |
| ublks_added++; |
| return 0; |
| fail: |
| put_device(dev); |
| return ret; |
| } |
| |
| static void ublk_stop_work_fn(struct work_struct *work) |
| { |
| struct ublk_device *ub = |
| container_of(work, struct ublk_device, stop_work); |
| |
| ublk_stop_dev(ub); |
| } |
| |
| /* align max io buffer size with PAGE_SIZE */ |
| static void ublk_align_max_io_size(struct ublk_device *ub) |
| { |
| unsigned int max_io_bytes = ub->dev_info.max_io_buf_bytes; |
| |
| ub->dev_info.max_io_buf_bytes = |
| round_down(max_io_bytes, PAGE_SIZE); |
| } |
| |
| static int ublk_add_tag_set(struct ublk_device *ub) |
| { |
| ub->tag_set.ops = &ublk_mq_ops; |
| ub->tag_set.nr_hw_queues = ub->dev_info.nr_hw_queues; |
| ub->tag_set.queue_depth = ub->dev_info.queue_depth; |
| ub->tag_set.numa_node = NUMA_NO_NODE; |
| ub->tag_set.cmd_size = sizeof(struct ublk_rq_data); |
| ub->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; |
| ub->tag_set.driver_data = ub; |
| return blk_mq_alloc_tag_set(&ub->tag_set); |
| } |
| |
| static void ublk_remove(struct ublk_device *ub) |
| { |
| ublk_stop_dev(ub); |
| cancel_work_sync(&ub->stop_work); |
| cancel_work_sync(&ub->quiesce_work); |
| cdev_device_del(&ub->cdev, &ub->cdev_dev); |
| ublk_put_device(ub); |
| ublks_added--; |
| } |
| |
| static struct ublk_device *ublk_get_device_from_id(int idx) |
| { |
| struct ublk_device *ub = NULL; |
| |
| if (idx < 0) |
| return NULL; |
| |
| spin_lock(&ublk_idr_lock); |
| ub = idr_find(&ublk_index_idr, idx); |
| if (ub) |
| ub = ublk_get_device(ub); |
| spin_unlock(&ublk_idr_lock); |
| |
| return ub; |
| } |
| |
| static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| const struct ublk_param_basic *p = &ub->params.basic; |
| int ublksrv_pid = (int)header->data[0]; |
| struct queue_limits lim = { |
| .logical_block_size = 1 << p->logical_bs_shift, |
| .physical_block_size = 1 << p->physical_bs_shift, |
| .io_min = 1 << p->io_min_shift, |
| .io_opt = 1 << p->io_opt_shift, |
| .max_hw_sectors = p->max_sectors, |
| .chunk_sectors = p->chunk_sectors, |
| .virt_boundary_mask = p->virt_boundary_mask, |
| .max_segments = USHRT_MAX, |
| .max_segment_size = UINT_MAX, |
| .dma_alignment = 3, |
| }; |
| struct gendisk *disk; |
| int ret = -EINVAL; |
| |
| if (ublksrv_pid <= 0) |
| return -EINVAL; |
| if (!(ub->params.types & UBLK_PARAM_TYPE_BASIC)) |
| return -EINVAL; |
| |
| if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) { |
| const struct ublk_param_discard *pd = &ub->params.discard; |
| |
| lim.discard_alignment = pd->discard_alignment; |
| lim.discard_granularity = pd->discard_granularity; |
| lim.max_hw_discard_sectors = pd->max_discard_sectors; |
| lim.max_write_zeroes_sectors = pd->max_write_zeroes_sectors; |
| lim.max_discard_segments = pd->max_discard_segments; |
| } |
| |
| if (ub->params.types & UBLK_PARAM_TYPE_ZONED) { |
| const struct ublk_param_zoned *p = &ub->params.zoned; |
| |
| if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED)) |
| return -EOPNOTSUPP; |
| |
| lim.features |= BLK_FEAT_ZONED; |
| lim.max_active_zones = p->max_active_zones; |
| lim.max_open_zones = p->max_open_zones; |
| lim.max_zone_append_sectors = p->max_zone_append_sectors; |
| } |
| |
| if (ub->params.basic.attrs & UBLK_ATTR_VOLATILE_CACHE) { |
| lim.features |= BLK_FEAT_WRITE_CACHE; |
| if (ub->params.basic.attrs & UBLK_ATTR_FUA) |
| lim.features |= BLK_FEAT_FUA; |
| } |
| |
| if (ub->params.basic.attrs & UBLK_ATTR_ROTATIONAL) |
| lim.features |= BLK_FEAT_ROTATIONAL; |
| |
| if (wait_for_completion_interruptible(&ub->completion) != 0) |
| return -EINTR; |
| |
| mutex_lock(&ub->mutex); |
| if (ub->dev_info.state == UBLK_S_DEV_LIVE || |
| test_bit(UB_STATE_USED, &ub->state)) { |
| ret = -EEXIST; |
| goto out_unlock; |
| } |
| |
| disk = blk_mq_alloc_disk(&ub->tag_set, &lim, NULL); |
| if (IS_ERR(disk)) { |
| ret = PTR_ERR(disk); |
| goto out_unlock; |
| } |
| sprintf(disk->disk_name, "ublkb%d", ub->ub_number); |
| disk->fops = &ub_fops; |
| disk->private_data = ub; |
| |
| ub->dev_info.ublksrv_pid = ublksrv_pid; |
| ub->ub_disk = disk; |
| |
| ublk_apply_params(ub); |
| |
| /* don't probe partitions if any one ubq daemon is un-trusted */ |
| if (ub->nr_privileged_daemon != ub->nr_queues_ready) |
| set_bit(GD_SUPPRESS_PART_SCAN, &disk->state); |
| |
| ublk_get_device(ub); |
| ub->dev_info.state = UBLK_S_DEV_LIVE; |
| |
| if (ublk_dev_is_zoned(ub)) { |
| ret = ublk_revalidate_disk_zones(ub); |
| if (ret) |
| goto out_put_cdev; |
| } |
| |
| ret = add_disk(disk); |
| if (ret) |
| goto out_put_cdev; |
| |
| set_bit(UB_STATE_USED, &ub->state); |
| |
| out_put_cdev: |
| if (ret) { |
| ub->dev_info.state = UBLK_S_DEV_DEAD; |
| ublk_put_device(ub); |
| } |
| if (ret) |
| put_disk(disk); |
| out_unlock: |
| mutex_unlock(&ub->mutex); |
| return ret; |
| } |
| |
| static int ublk_ctrl_get_queue_affinity(struct ublk_device *ub, |
| struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| void __user *argp = (void __user *)(unsigned long)header->addr; |
| cpumask_var_t cpumask; |
| unsigned long queue; |
| unsigned int retlen; |
| unsigned int i; |
| int ret; |
| |
| if (header->len * BITS_PER_BYTE < nr_cpu_ids) |
| return -EINVAL; |
| if (header->len & (sizeof(unsigned long)-1)) |
| return -EINVAL; |
| if (!header->addr) |
| return -EINVAL; |
| |
| queue = header->data[0]; |
| if (queue >= ub->dev_info.nr_hw_queues) |
| return -EINVAL; |
| |
| if (!zalloc_cpumask_var(&cpumask, GFP_KERNEL)) |
| return -ENOMEM; |
| |
| for_each_possible_cpu(i) { |
| if (ub->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[i] == queue) |
| cpumask_set_cpu(i, cpumask); |
| } |
| |
| ret = -EFAULT; |
| retlen = min_t(unsigned short, header->len, cpumask_size()); |
| if (copy_to_user(argp, cpumask, retlen)) |
| goto out_free_cpumask; |
| if (retlen != header->len && |
| clear_user(argp + retlen, header->len - retlen)) |
| goto out_free_cpumask; |
| |
| ret = 0; |
| out_free_cpumask: |
| free_cpumask_var(cpumask); |
| return ret; |
| } |
| |
| static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info) |
| { |
| pr_devel("%s: dev id %d flags %llx\n", __func__, |
| info->dev_id, info->flags); |
| pr_devel("\t nr_hw_queues %d queue_depth %d\n", |
| info->nr_hw_queues, info->queue_depth); |
| } |
| |
| static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| void __user *argp = (void __user *)(unsigned long)header->addr; |
| struct ublksrv_ctrl_dev_info info; |
| struct ublk_device *ub; |
| int ret = -EINVAL; |
| |
| if (header->len < sizeof(info) || !header->addr) |
| return -EINVAL; |
| if (header->queue_id != (u16)-1) { |
| pr_warn("%s: queue_id is wrong %x\n", |
| __func__, header->queue_id); |
| return -EINVAL; |
| } |
| |
| if (copy_from_user(&info, argp, sizeof(info))) |
| return -EFAULT; |
| |
| if (capable(CAP_SYS_ADMIN)) |
| info.flags &= ~UBLK_F_UNPRIVILEGED_DEV; |
| else if (!(info.flags & UBLK_F_UNPRIVILEGED_DEV)) |
| return -EPERM; |
| |
| /* |
| * unprivileged device can't be trusted, but RECOVERY and |
| * RECOVERY_REISSUE still may hang error handling, so can't |
| * support recovery features for unprivileged ublk now |
| * |
| * TODO: provide forward progress for RECOVERY handler, so that |
| * unprivileged device can benefit from it |
| */ |
| if (info.flags & UBLK_F_UNPRIVILEGED_DEV) |
| info.flags &= ~(UBLK_F_USER_RECOVERY_REISSUE | |
| UBLK_F_USER_RECOVERY); |
| |
| /* the created device is always owned by current user */ |
| ublk_store_owner_uid_gid(&info.owner_uid, &info.owner_gid); |
| |
| if (header->dev_id != info.dev_id) { |
| pr_warn("%s: dev id not match %u %u\n", |
| __func__, header->dev_id, info.dev_id); |
| return -EINVAL; |
| } |
| |
| if (header->dev_id != U32_MAX && header->dev_id >= UBLK_MAX_UBLKS) { |
| pr_warn("%s: dev id is too large. Max supported is %d\n", |
| __func__, UBLK_MAX_UBLKS - 1); |
| return -EINVAL; |
| } |
| |
| ublk_dump_dev_info(&info); |
| |
| ret = mutex_lock_killable(&ublk_ctl_mutex); |
| if (ret) |
| return ret; |
| |
| ret = -EACCES; |
| if (ublks_added >= ublks_max) |
| goto out_unlock; |
| |
| ret = -ENOMEM; |
| ub = kzalloc(sizeof(*ub), GFP_KERNEL); |
| if (!ub) |
| goto out_unlock; |
| mutex_init(&ub->mutex); |
| spin_lock_init(&ub->lock); |
| INIT_WORK(&ub->quiesce_work, ublk_quiesce_work_fn); |
| INIT_WORK(&ub->stop_work, ublk_stop_work_fn); |
| |
| ret = ublk_alloc_dev_number(ub, header->dev_id); |
| if (ret < 0) |
| goto out_free_ub; |
| |
| memcpy(&ub->dev_info, &info, sizeof(info)); |
| |
| /* update device id */ |
| ub->dev_info.dev_id = ub->ub_number; |
| |
| /* |
| * 64bit flags will be copied back to userspace as feature |
| * negotiation result, so have to clear flags which driver |
| * doesn't support yet, then userspace can get correct flags |
| * (features) to handle. |
| */ |
| ub->dev_info.flags &= UBLK_F_ALL; |
| |
| ub->dev_info.flags |= UBLK_F_CMD_IOCTL_ENCODE | |
| UBLK_F_URING_CMD_COMP_IN_TASK; |
| |
| /* GET_DATA isn't needed any more with USER_COPY */ |
| if (ublk_dev_is_user_copy(ub)) |
| ub->dev_info.flags &= ~UBLK_F_NEED_GET_DATA; |
| |
| /* Zoned storage support requires user copy feature */ |
| if (ublk_dev_is_zoned(ub) && |
| (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) || !ublk_dev_is_user_copy(ub))) { |
| ret = -EINVAL; |
| goto out_free_dev_number; |
| } |
| |
| /* We are not ready to support zero copy */ |
| ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY; |
| |
| ub->dev_info.nr_hw_queues = min_t(unsigned int, |
| ub->dev_info.nr_hw_queues, nr_cpu_ids); |
| ublk_align_max_io_size(ub); |
| |
| ret = ublk_init_queues(ub); |
| if (ret) |
| goto out_free_dev_number; |
| |
| ret = ublk_add_tag_set(ub); |
| if (ret) |
| goto out_deinit_queues; |
| |
| ret = -EFAULT; |
| if (copy_to_user(argp, &ub->dev_info, sizeof(info))) |
| goto out_free_tag_set; |
| |
| /* |
| * Add the char dev so that ublksrv daemon can be setup. |
| * ublk_add_chdev() will cleanup everything if it fails. |
| */ |
| ret = ublk_add_chdev(ub); |
| goto out_unlock; |
| |
| out_free_tag_set: |
| blk_mq_free_tag_set(&ub->tag_set); |
| out_deinit_queues: |
| ublk_deinit_queues(ub); |
| out_free_dev_number: |
| ublk_free_dev_number(ub); |
| out_free_ub: |
| mutex_destroy(&ub->mutex); |
| kfree(ub); |
| out_unlock: |
| mutex_unlock(&ublk_ctl_mutex); |
| return ret; |
| } |
| |
| static inline bool ublk_idr_freed(int id) |
| { |
| void *ptr; |
| |
| spin_lock(&ublk_idr_lock); |
| ptr = idr_find(&ublk_index_idr, id); |
| spin_unlock(&ublk_idr_lock); |
| |
| return ptr == NULL; |
| } |
| |
| static int ublk_ctrl_del_dev(struct ublk_device **p_ub, bool wait) |
| { |
| struct ublk_device *ub = *p_ub; |
| int idx = ub->ub_number; |
| int ret; |
| |
| ret = mutex_lock_killable(&ublk_ctl_mutex); |
| if (ret) |
| return ret; |
| |
| if (!test_bit(UB_STATE_DELETED, &ub->state)) { |
| ublk_remove(ub); |
| set_bit(UB_STATE_DELETED, &ub->state); |
| } |
| |
| /* Mark the reference as consumed */ |
| *p_ub = NULL; |
| ublk_put_device(ub); |
| mutex_unlock(&ublk_ctl_mutex); |
| |
| /* |
| * Wait until the idr is removed, then it can be reused after |
| * DEL_DEV command is returned. |
| * |
| * If we returns because of user interrupt, future delete command |
| * may come: |
| * |
| * - the device number isn't freed, this device won't or needn't |
| * be deleted again, since UB_STATE_DELETED is set, and device |
| * will be released after the last reference is dropped |
| * |
| * - the device number is freed already, we will not find this |
| * device via ublk_get_device_from_id() |
| */ |
| if (wait && wait_event_interruptible(ublk_idr_wq, ublk_idr_freed(idx))) |
| return -EINTR; |
| return 0; |
| } |
| |
| static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| |
| pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n", |
| __func__, cmd->cmd_op, header->dev_id, header->queue_id, |
| header->data[0], header->addr, header->len); |
| } |
| |
| static int ublk_ctrl_stop_dev(struct ublk_device *ub) |
| { |
| ublk_stop_dev(ub); |
| cancel_work_sync(&ub->stop_work); |
| cancel_work_sync(&ub->quiesce_work); |
| |
| return 0; |
| } |
| |
| static int ublk_ctrl_get_dev_info(struct ublk_device *ub, |
| struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| void __user *argp = (void __user *)(unsigned long)header->addr; |
| |
| if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr) |
| return -EINVAL; |
| |
| if (copy_to_user(argp, &ub->dev_info, sizeof(ub->dev_info))) |
| return -EFAULT; |
| |
| return 0; |
| } |
| |
| /* TYPE_DEVT is readonly, so fill it up before returning to userspace */ |
| static void ublk_ctrl_fill_params_devt(struct ublk_device *ub) |
| { |
| ub->params.devt.char_major = MAJOR(ub->cdev_dev.devt); |
| ub->params.devt.char_minor = MINOR(ub->cdev_dev.devt); |
| |
| if (ub->ub_disk) { |
| ub->params.devt.disk_major = MAJOR(disk_devt(ub->ub_disk)); |
| ub->params.devt.disk_minor = MINOR(disk_devt(ub->ub_disk)); |
| } else { |
| ub->params.devt.disk_major = 0; |
| ub->params.devt.disk_minor = 0; |
| } |
| ub->params.types |= UBLK_PARAM_TYPE_DEVT; |
| } |
| |
| static int ublk_ctrl_get_params(struct ublk_device *ub, |
| struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| void __user *argp = (void __user *)(unsigned long)header->addr; |
| struct ublk_params_header ph; |
| int ret; |
| |
| if (header->len <= sizeof(ph) || !header->addr) |
| return -EINVAL; |
| |
| if (copy_from_user(&ph, argp, sizeof(ph))) |
| return -EFAULT; |
| |
| if (ph.len > header->len || !ph.len) |
| return -EINVAL; |
| |
| if (ph.len > sizeof(struct ublk_params)) |
| ph.len = sizeof(struct ublk_params); |
| |
| mutex_lock(&ub->mutex); |
| ublk_ctrl_fill_params_devt(ub); |
| if (copy_to_user(argp, &ub->params, ph.len)) |
| ret = -EFAULT; |
| else |
| ret = 0; |
| mutex_unlock(&ub->mutex); |
| |
| return ret; |
| } |
| |
| static int ublk_ctrl_set_params(struct ublk_device *ub, |
| struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| void __user *argp = (void __user *)(unsigned long)header->addr; |
| struct ublk_params_header ph; |
| int ret = -EFAULT; |
| |
| if (header->len <= sizeof(ph) || !header->addr) |
| return -EINVAL; |
| |
| if (copy_from_user(&ph, argp, sizeof(ph))) |
| return -EFAULT; |
| |
| if (ph.len > header->len || !ph.len || !ph.types) |
| return -EINVAL; |
| |
| if (ph.len > sizeof(struct ublk_params)) |
| ph.len = sizeof(struct ublk_params); |
| |
| /* parameters can only be changed when device isn't live */ |
| mutex_lock(&ub->mutex); |
| if (ub->dev_info.state == UBLK_S_DEV_LIVE) { |
| ret = -EACCES; |
| } else if (copy_from_user(&ub->params, argp, ph.len)) { |
| ret = -EFAULT; |
| } else { |
| /* clear all we don't support yet */ |
| ub->params.types &= UBLK_PARAM_TYPE_ALL; |
| ret = ublk_validate_params(ub); |
| if (ret) |
| ub->params.types = 0; |
| } |
| mutex_unlock(&ub->mutex); |
| |
| return ret; |
| } |
| |
| static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq) |
| { |
| int i; |
| |
| WARN_ON_ONCE(!(ubq->ubq_daemon && ubq_daemon_is_dying(ubq))); |
| |
| /* All old ioucmds have to be completed */ |
| ubq->nr_io_ready = 0; |
| /* old daemon is PF_EXITING, put it now */ |
| put_task_struct(ubq->ubq_daemon); |
| /* We have to reset it to NULL, otherwise ub won't accept new FETCH_REQ */ |
| ubq->ubq_daemon = NULL; |
| ubq->timeout = false; |
| ubq->canceling = false; |
| |
| for (i = 0; i < ubq->q_depth; i++) { |
| struct ublk_io *io = &ubq->ios[i]; |
| |
| /* forget everything now and be ready for new FETCH_REQ */ |
| io->flags = 0; |
| io->cmd = NULL; |
| io->addr = 0; |
| } |
| } |
| |
| static int ublk_ctrl_start_recovery(struct ublk_device *ub, |
| struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| int ret = -EINVAL; |
| int i; |
| |
| mutex_lock(&ub->mutex); |
| if (!ublk_can_use_recovery(ub)) |
| goto out_unlock; |
| if (!ub->nr_queues_ready) |
| goto out_unlock; |
| /* |
| * START_RECOVERY is only allowd after: |
| * |
| * (1) UB_STATE_OPEN is not set, which means the dying process is exited |
| * and related io_uring ctx is freed so file struct of /dev/ublkcX is |
| * released. |
| * |
| * (2) UBLK_S_DEV_QUIESCED is set, which means the quiesce_work: |
| * (a)has quiesced request queue |
| * (b)has requeued every inflight rqs whose io_flags is ACTIVE |
| * (c)has requeued/aborted every inflight rqs whose io_flags is NOT ACTIVE |
| * (d)has completed/camceled all ioucmds owned by ther dying process |
| */ |
| if (test_bit(UB_STATE_OPEN, &ub->state) || |
| ub->dev_info.state != UBLK_S_DEV_QUIESCED) { |
| ret = -EBUSY; |
| goto out_unlock; |
| } |
| pr_devel("%s: start recovery for dev id %d.\n", __func__, header->dev_id); |
| for (i = 0; i < ub->dev_info.nr_hw_queues; i++) |
| ublk_queue_reinit(ub, ublk_get_queue(ub, i)); |
| /* set to NULL, otherwise new ubq_daemon cannot mmap the io_cmd_buf */ |
| ub->mm = NULL; |
| ub->nr_queues_ready = 0; |
| ub->nr_privileged_daemon = 0; |
| init_completion(&ub->completion); |
| ret = 0; |
| out_unlock: |
| mutex_unlock(&ub->mutex); |
| return ret; |
| } |
| |
| static int ublk_ctrl_end_recovery(struct ublk_device *ub, |
| struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| int ublksrv_pid = (int)header->data[0]; |
| int ret = -EINVAL; |
| |
| pr_devel("%s: Waiting for new ubq_daemons(nr: %d) are ready, dev id %d...\n", |
| __func__, ub->dev_info.nr_hw_queues, header->dev_id); |
| /* wait until new ubq_daemon sending all FETCH_REQ */ |
| if (wait_for_completion_interruptible(&ub->completion)) |
| return -EINTR; |
| |
| pr_devel("%s: All new ubq_daemons(nr: %d) are ready, dev id %d\n", |
| __func__, ub->dev_info.nr_hw_queues, header->dev_id); |
| |
| mutex_lock(&ub->mutex); |
| if (!ublk_can_use_recovery(ub)) |
| goto out_unlock; |
| |
| if (ub->dev_info.state != UBLK_S_DEV_QUIESCED) { |
| ret = -EBUSY; |
| goto out_unlock; |
| } |
| ub->dev_info.ublksrv_pid = ublksrv_pid; |
| pr_devel("%s: new ublksrv_pid %d, dev id %d\n", |
| __func__, ublksrv_pid, header->dev_id); |
| blk_mq_unquiesce_queue(ub->ub_disk->queue); |
| pr_devel("%s: queue unquiesced, dev id %d.\n", |
| __func__, header->dev_id); |
| blk_mq_kick_requeue_list(ub->ub_disk->queue); |
| ub->dev_info.state = UBLK_S_DEV_LIVE; |
| ret = 0; |
| out_unlock: |
| mutex_unlock(&ub->mutex); |
| return ret; |
| } |
| |
| static int ublk_ctrl_get_features(struct io_uring_cmd *cmd) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| void __user *argp = (void __user *)(unsigned long)header->addr; |
| u64 features = UBLK_F_ALL & ~UBLK_F_SUPPORT_ZERO_COPY; |
| |
| if (header->len != UBLK_FEATURES_LEN || !header->addr) |
| return -EINVAL; |
| |
| if (copy_to_user(argp, &features, UBLK_FEATURES_LEN)) |
| return -EFAULT; |
| |
| return 0; |
| } |
| |
| /* |
| * All control commands are sent via /dev/ublk-control, so we have to check |
| * the destination device's permission |
| */ |
| static int ublk_char_dev_permission(struct ublk_device *ub, |
| const char *dev_path, int mask) |
| { |
| int err; |
| struct path path; |
| struct kstat stat; |
| |
| err = kern_path(dev_path, LOOKUP_FOLLOW, &path); |
| if (err) |
| return err; |
| |
| err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT); |
| if (err) |
| goto exit; |
| |
| err = -EPERM; |
| if (stat.rdev != ub->cdev_dev.devt || !S_ISCHR(stat.mode)) |
| goto exit; |
| |
| err = inode_permission(&nop_mnt_idmap, |
| d_backing_inode(path.dentry), mask); |
| exit: |
| path_put(&path); |
| return err; |
| } |
| |
| static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub, |
| struct io_uring_cmd *cmd) |
| { |
| struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)io_uring_sqe_cmd(cmd->sqe); |
| bool unprivileged = ub->dev_info.flags & UBLK_F_UNPRIVILEGED_DEV; |
| void __user *argp = (void __user *)(unsigned long)header->addr; |
| char *dev_path = NULL; |
| int ret = 0; |
| int mask; |
| |
| if (!unprivileged) { |
| if (!capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| /* |
| * The new added command of UBLK_CMD_GET_DEV_INFO2 includes |
| * char_dev_path in payload too, since userspace may not |
| * know if the specified device is created as unprivileged |
| * mode. |
| */ |
| if (_IOC_NR(cmd->cmd_op) != UBLK_CMD_GET_DEV_INFO2) |
| return 0; |
| } |
| |
| /* |
| * User has to provide the char device path for unprivileged ublk |
| * |
| * header->addr always points to the dev path buffer, and |
| * header->dev_path_len records length of dev path buffer. |
| */ |
| if (!header->dev_path_len || header->dev_path_len > PATH_MAX) |
| return -EINVAL; |
| |
| if (header->len < header->dev_path_len) |
| return -EINVAL; |
| |
| dev_path = memdup_user_nul(argp, header->dev_path_len); |
| if (IS_ERR(dev_path)) |
| return PTR_ERR(dev_path); |
| |
| ret = -EINVAL; |
| switch (_IOC_NR(cmd->cmd_op)) { |
| case UBLK_CMD_GET_DEV_INFO: |
| case UBLK_CMD_GET_DEV_INFO2: |
| case UBLK_CMD_GET_QUEUE_AFFINITY: |
| case UBLK_CMD_GET_PARAMS: |
| case (_IOC_NR(UBLK_U_CMD_GET_FEATURES)): |
| mask = MAY_READ; |
| break; |
| case UBLK_CMD_START_DEV: |
| case UBLK_CMD_STOP_DEV: |
| case UBLK_CMD_ADD_DEV: |
| case UBLK_CMD_DEL_DEV: |
| case UBLK_CMD_SET_PARAMS: |
| case UBLK_CMD_START_USER_RECOVERY: |
| case UBLK_CMD_END_USER_RECOVERY: |
| mask = MAY_READ | MAY_WRITE; |
| break; |
| default: |
| goto exit; |
| } |
| |
| ret = ublk_char_dev_permission(ub, dev_path, mask); |
| if (!ret) { |
| header->len -= header->dev_path_len; |
| header->addr += header->dev_path_len; |
| } |
| pr_devel("%s: dev id %d cmd_op %x uid %d gid %d path %s ret %d\n", |
| __func__, ub->ub_number, cmd->cmd_op, |
| ub->dev_info.owner_uid, ub->dev_info.owner_gid, |
| dev_path, ret); |
| exit: |
| kfree(dev_path); |
| return ret; |
| } |
| |
| static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, |
| unsigned int issue_flags) |
| { |
| const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe); |
| struct ublk_device *ub = NULL; |
| u32 cmd_op = cmd->cmd_op; |
| int ret = -EINVAL; |
| |
| if (issue_flags & IO_URING_F_NONBLOCK) |
| return -EAGAIN; |
| |
| ublk_ctrl_cmd_dump(cmd); |
| |
| if (!(issue_flags & IO_URING_F_SQE128)) |
| goto out; |
| |
| ret = ublk_check_cmd_op(cmd_op); |
| if (ret) |
| goto out; |
| |
| if (cmd_op == UBLK_U_CMD_GET_FEATURES) { |
| ret = ublk_ctrl_get_features(cmd); |
| goto out; |
| } |
| |
| if (_IOC_NR(cmd_op) != UBLK_CMD_ADD_DEV) { |
| ret = -ENODEV; |
| ub = ublk_get_device_from_id(header->dev_id); |
| if (!ub) |
| goto out; |
| |
| ret = ublk_ctrl_uring_cmd_permission(ub, cmd); |
| if (ret) |
| goto put_dev; |
| } |
| |
| switch (_IOC_NR(cmd_op)) { |
| case UBLK_CMD_START_DEV: |
| ret = ublk_ctrl_start_dev(ub, cmd); |
| break; |
| case UBLK_CMD_STOP_DEV: |
| ret = ublk_ctrl_stop_dev(ub); |
| break; |
| case UBLK_CMD_GET_DEV_INFO: |
| case UBLK_CMD_GET_DEV_INFO2: |
| ret = ublk_ctrl_get_dev_info(ub, cmd); |
| break; |
| case UBLK_CMD_ADD_DEV: |
| ret = ublk_ctrl_add_dev(cmd); |
| break; |
| case UBLK_CMD_DEL_DEV: |
| ret = ublk_ctrl_del_dev(&ub, true); |
| break; |
| case UBLK_CMD_DEL_DEV_ASYNC: |
| ret = ublk_ctrl_del_dev(&ub, false); |
| break; |
| case UBLK_CMD_GET_QUEUE_AFFINITY: |
| ret = ublk_ctrl_get_queue_affinity(ub, cmd); |
| break; |
| case UBLK_CMD_GET_PARAMS: |
| ret = ublk_ctrl_get_params(ub, cmd); |
| break; |
| case UBLK_CMD_SET_PARAMS: |
| ret = ublk_ctrl_set_params(ub, cmd); |
| break; |
| case UBLK_CMD_START_USER_RECOVERY: |
| ret = ublk_ctrl_start_recovery(ub, cmd); |
| break; |
| case UBLK_CMD_END_USER_RECOVERY: |
| ret = ublk_ctrl_end_recovery(ub, cmd); |
| break; |
| default: |
| ret = -ENOTSUPP; |
| break; |
| } |
| |
| put_dev: |
| if (ub) |
| ublk_put_device(ub); |
| out: |
| io_uring_cmd_done(cmd, ret, 0, issue_flags); |
| pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n", |
| __func__, ret, cmd->cmd_op, header->dev_id, header->queue_id); |
| return -EIOCBQUEUED; |
| } |
| |
| static const struct file_operations ublk_ctl_fops = { |
| .open = nonseekable_open, |
| .uring_cmd = ublk_ctrl_uring_cmd, |
| .owner = THIS_MODULE, |
| .llseek = noop_llseek, |
| }; |
| |
| static struct miscdevice ublk_misc = { |
| .minor = MISC_DYNAMIC_MINOR, |
| .name = "ublk-control", |
| .fops = &ublk_ctl_fops, |
| }; |
| |
| static int __init ublk_init(void) |
| { |
| int ret; |
| |
| BUILD_BUG_ON((u64)UBLKSRV_IO_BUF_OFFSET + |
| UBLKSRV_IO_BUF_TOTAL_SIZE < UBLKSRV_IO_BUF_OFFSET); |
| |
| init_waitqueue_head(&ublk_idr_wq); |
| |
| ret = misc_register(&ublk_misc); |
| if (ret) |
| return ret; |
| |
| ret = alloc_chrdev_region(&ublk_chr_devt, 0, UBLK_MINORS, "ublk-char"); |
| if (ret) |
| goto unregister_mis; |
| |
| ret = class_register(&ublk_chr_class); |
| if (ret) |
| goto free_chrdev_region; |
| |
| return 0; |
| |
| free_chrdev_region: |
| unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); |
| unregister_mis: |
| misc_deregister(&ublk_misc); |
| return ret; |
| } |
| |
| static void __exit ublk_exit(void) |
| { |
| struct ublk_device *ub; |
| int id; |
| |
| idr_for_each_entry(&ublk_index_idr, ub, id) |
| ublk_remove(ub); |
| |
| class_unregister(&ublk_chr_class); |
| misc_deregister(&ublk_misc); |
| |
| idr_destroy(&ublk_index_idr); |
| unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); |
| } |
| |
| module_init(ublk_init); |
| module_exit(ublk_exit); |
| |
| static int ublk_set_max_ublks(const char *buf, const struct kernel_param *kp) |
| { |
| return param_set_uint_minmax(buf, kp, 0, UBLK_MAX_UBLKS); |
| } |
| |
| static int ublk_get_max_ublks(char *buf, const struct kernel_param *kp) |
| { |
| return sysfs_emit(buf, "%u\n", ublks_max); |
| } |
| |
| static const struct kernel_param_ops ublk_max_ublks_ops = { |
| .set = ublk_set_max_ublks, |
| .get = ublk_get_max_ublks, |
| }; |
| |
| module_param_cb(ublks_max, &ublk_max_ublks_ops, &ublks_max, 0644); |
| MODULE_PARM_DESC(ublks_max, "max number of ublk devices allowed to add(default: 64)"); |
| |
| MODULE_AUTHOR("Ming Lei <ming.lei@redhat.com>"); |
| MODULE_DESCRIPTION("Userspace block device"); |
| MODULE_LICENSE("GPL"); |