diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2022-06-01 16:28:44 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-06-01 18:12:41 +0200 |
| commit | 61c1b44a21d70d4783db02198fbf68b132f4953c (patch) | |
| tree | 6641f4cc04ffc4d1b6482f99880638f7e976577b /fs/io_uring.c | |
| parent | io_uring: let IORING_OP_FILES_UPDATE support choosing fixed file slots (diff) | |
| download | linux-61c1b44a21d70d4783db02198fbf68b132f4953c.tar.xz linux-61c1b44a21d70d4783db02198fbf68b132f4953c.zip | |
io_uring: fix deadlock on iowq file slot alloc
io_fixed_fd_install() can grab uring_lock in the slot allocation path
when called from io-wq, and then call into io_install_fixed_file(),
which will lock it again. Pull all locking out of
io_install_fixed_file() into io_fixed_fd_install().
Fixes: 1339f24b336db ("io_uring: allow allocated fixed files for openat/openat2")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/64116172a9d0b85b85300346bb280f3657aafc26.1654087283.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to '')
| -rw-r--r-- | fs/io_uring.c | 36 |
1 files changed, 15 insertions, 21 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index ed3416a7b2e9..495353437228 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5448,27 +5448,24 @@ static int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags, struct io_ring_ctx *ctx = req->ctx; int ret; + io_ring_submit_lock(ctx, issue_flags); + if (alloc_slot) { - io_ring_submit_lock(ctx, issue_flags); ret = io_file_bitmap_get(ctx); - if (unlikely(ret < 0)) { - io_ring_submit_unlock(ctx, issue_flags); - fput(file); - return ret; - } - + if (unlikely(ret < 0)) + goto err; file_slot = ret; } else { file_slot--; } ret = io_install_fixed_file(req, file, issue_flags, file_slot); - if (alloc_slot) { - io_ring_submit_unlock(ctx, issue_flags); - if (!ret) - return file_slot; - } - + if (!ret && alloc_slot) + ret = file_slot; +err: + io_ring_submit_unlock(ctx, issue_flags); + if (unlikely(ret < 0)) + fput(file); return ret; } @@ -10179,21 +10176,19 @@ static int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx, static int io_install_fixed_file(struct io_kiocb *req, struct file *file, unsigned int issue_flags, u32 slot_index) + __must_hold(&req->ctx->uring_lock) { struct io_ring_ctx *ctx = req->ctx; bool needs_switch = false; struct io_fixed_file *file_slot; - int ret = -EBADF; + int ret; - io_ring_submit_lock(ctx, issue_flags); if (file->f_op == &io_uring_fops) - goto err; - ret = -ENXIO; + return -EBADF; if (!ctx->file_data) - goto err; - ret = -EINVAL; + return -ENXIO; if (slot_index >= ctx->nr_user_files) - goto err; + return -EINVAL; slot_index = array_index_nospec(slot_index, ctx->nr_user_files); file_slot = io_fixed_file_slot(&ctx->file_table, slot_index); @@ -10224,7 +10219,6 @@ static int io_install_fixed_file(struct io_kiocb *req, struct file *file, err: if (needs_switch) io_rsrc_node_switch(ctx, ctx->file_data); - io_ring_submit_unlock(ctx, issue_flags); if (ret) fput(file); return ret; |