io_uring: split out open/close operations
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/io_uring/openclose.c b/io_uring/openclose.c
new file mode 100644
index 0000000..fa35bd5
--- /dev/null
+++ b/io_uring/openclose.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/fsnotify.h>
+#include <linux/namei.h>
+#include <linux/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "../fs/internal.h"
+
+#include "io_uring_types.h"
+#include "io_uring.h"
+#include "openclose.h"
+
+struct io_open {
+ struct file *file;
+ int dfd;
+ u32 file_slot;
+ struct filename *filename;
+ struct open_how how;
+ unsigned long nofile;
+};
+
+struct io_close {
+ struct file *file;
+ int fd;
+ u32 file_slot;
+};
+
+static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_open *open = io_kiocb_to_cmd(req);
+ const char __user *fname;
+ int ret;
+
+ if (unlikely(sqe->buf_index))
+ return -EINVAL;
+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
+ return -EBADF;
+
+ /* open.how should be already initialised */
+ if (!(open->how.flags & O_PATH) && force_o_largefile())
+ open->how.flags |= O_LARGEFILE;
+
+ open->dfd = READ_ONCE(sqe->fd);
+ fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ open->filename = getname(fname);
+ if (IS_ERR(open->filename)) {
+ ret = PTR_ERR(open->filename);
+ open->filename = NULL;
+ return ret;
+ }
+
+ open->file_slot = READ_ONCE(sqe->file_index);
+ if (open->file_slot && (open->how.flags & O_CLOEXEC))
+ return -EINVAL;
+
+ open->nofile = rlimit(RLIMIT_NOFILE);
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_open *open = io_kiocb_to_cmd(req);
+ u64 mode = READ_ONCE(sqe->len);
+ u64 flags = READ_ONCE(sqe->open_flags);
+
+ open->how = build_open_how(flags, mode);
+ return __io_openat_prep(req, sqe);
+}
+
+int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_open *open = io_kiocb_to_cmd(req);
+ struct open_how __user *how;
+ size_t len;
+ int ret;
+
+ 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(&open->how, sizeof(open->how), how, len);
+ if (ret)
+ return ret;
+
+ return __io_openat_prep(req, sqe);
+}
+
+int io_openat2(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_open *open = io_kiocb_to_cmd(req);
+ struct open_flags op;
+ struct file *file;
+ bool resolve_nonblock, nonblock_set;
+ bool fixed = !!open->file_slot;
+ int ret;
+
+ ret = build_open_flags(&open->how, &op);
+ if (ret)
+ goto err;
+ nonblock_set = op.open_flag & O_NONBLOCK;
+ resolve_nonblock = open->how.resolve & RESOLVE_CACHED;
+ if (issue_flags & IO_URING_F_NONBLOCK) {
+ /*
+ * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open,
+ * it'll always -EAGAIN
+ */
+ if (open->how.flags & (O_TRUNC | O_CREAT | O_TMPFILE))
+ return -EAGAIN;
+ op.lookup_flags |= LOOKUP_CACHED;
+ op.open_flag |= O_NONBLOCK;
+ }
+
+ if (!fixed) {
+ ret = __get_unused_fd_flags(open->how.flags, open->nofile);
+ if (ret < 0)
+ goto err;
+ }
+
+ file = do_filp_open(open->dfd, open->filename, &op);
+ if (IS_ERR(file)) {
+ /*
+ * We could hang on to this 'fd' on retrying, but seems like
+ * marginal gain for something that is now known to be a slower
+ * path. So just put it, and we'll get a new one when we retry.
+ */
+ if (!fixed)
+ put_unused_fd(ret);
+
+ ret = PTR_ERR(file);
+ /* only retry if RESOLVE_CACHED wasn't already set by application */
+ if (ret == -EAGAIN &&
+ (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK)))
+ return -EAGAIN;
+ goto err;
+ }
+
+ if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set)
+ file->f_flags &= ~O_NONBLOCK;
+ fsnotify_open(file);
+
+ if (!fixed)
+ fd_install(ret, file);
+ else
+ ret = io_fixed_fd_install(req, issue_flags, file,
+ open->file_slot);
+err:
+ putname(open->filename);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_set_res(req, ret, 0);
+ return IOU_OK;
+}
+
+int io_openat(struct io_kiocb *req, unsigned int issue_flags)
+{
+ return io_openat2(req, issue_flags);
+}
+
+void io_open_cleanup(struct io_kiocb *req)
+{
+ struct io_open *open = io_kiocb_to_cmd(req);
+
+ if (open->filename)
+ putname(open->filename);
+}
+
+int __io_close_fixed(struct io_kiocb *req, unsigned int issue_flags,
+ unsigned int offset)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_fixed_file *file_slot;
+ struct file *file;
+ int ret;
+
+ io_ring_submit_lock(ctx, issue_flags);
+ ret = -ENXIO;
+ if (unlikely(!ctx->file_data))
+ goto out;
+ ret = -EINVAL;
+ if (offset >= ctx->nr_user_files)
+ goto out;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ goto out;
+
+ offset = array_index_nospec(offset, ctx->nr_user_files);
+ file_slot = io_fixed_file_slot(&ctx->file_table, offset);
+ ret = -EBADF;
+ if (!file_slot->file_ptr)
+ goto out;
+
+ file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+ ret = io_queue_rsrc_removal(ctx->file_data, offset, ctx->rsrc_node, file);
+ if (ret)
+ goto out;
+
+ file_slot->file_ptr = 0;
+ io_file_bitmap_clear(&ctx->file_table, offset);
+ io_rsrc_node_switch(ctx, ctx->file_data);
+ ret = 0;
+out:
+ io_ring_submit_unlock(ctx, issue_flags);
+ return ret;
+}
+
+static inline int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_close *close = io_kiocb_to_cmd(req);
+
+ return __io_close_fixed(req, issue_flags, close->file_slot - 1);
+}
+
+int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_close *close = io_kiocb_to_cmd(req);
+
+ if (sqe->off || sqe->addr || sqe->len || sqe->rw_flags || sqe->buf_index)
+ return -EINVAL;
+ if (req->flags & REQ_F_FIXED_FILE)
+ return -EBADF;
+
+ close->fd = READ_ONCE(sqe->fd);
+ close->file_slot = READ_ONCE(sqe->file_index);
+ if (close->file_slot && close->fd)
+ return -EINVAL;
+
+ return 0;
+}
+
+int io_close(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct files_struct *files = current->files;
+ struct io_close *close = io_kiocb_to_cmd(req);
+ struct fdtable *fdt;
+ struct file *file;
+ int ret = -EBADF;
+
+ if (close->file_slot) {
+ ret = io_close_fixed(req, issue_flags);
+ goto err;
+ }
+
+ spin_lock(&files->file_lock);
+ fdt = files_fdtable(files);
+ if (close->fd >= fdt->max_fds) {
+ spin_unlock(&files->file_lock);
+ goto err;
+ }
+ file = rcu_dereference_protected(fdt->fd[close->fd],
+ lockdep_is_held(&files->file_lock));
+ if (!file || io_is_uring_fops(file)) {
+ spin_unlock(&files->file_lock);
+ goto err;
+ }
+
+ /* if the file has a flush method, be safe and punt to async */
+ if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) {
+ spin_unlock(&files->file_lock);
+ return -EAGAIN;
+ }
+
+ file = __close_fd_get_file(close->fd);
+ spin_unlock(&files->file_lock);
+ if (!file)
+ goto err;
+
+ /* No ->flush() or already async, safely close from here */
+ ret = filp_close(file, current->files);
+err:
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_set_res(req, ret, 0);
+ return IOU_OK;
+}
