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| author |   Pavel Begunkov <asml.silence@gmail.com> | 2019-12-18 19:53:45 +0300 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2019-12-18 10:01:49 -0700 |
| commit | 7c504e65206a4379ff38fe41d21b32b6c2c3e53e (patch) | |
| tree | 7badbc25ff49df5c2493cd5516b9dcbdfa8d7b50 /fs | |
| parent | io_uring: warn about unhandled opcode (diff) | |
| download | linux-dev-7c504e65206a4379ff38fe41d21b32b6c2c3e53e.tar.xz linux-dev-7c504e65206a4379ff38fe41d21b32b6c2c3e53e.zip | |
io_uring: don't wait when under-submitting
There is no reliable way to submit and wait in a single syscall, as
io_submit_sqes() may under-consume sqes (in case of an early error).
Then it will wait for not-yet-submitted requests, deadlocking the user
in most cases.
Don't wait/poll if can't submit all sqes
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/io_uring.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 1d4e7332ccae..81e7fe6dee18 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5135,6 +5135,9 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, submitted = io_submit_sqes(ctx, to_submit, f.file, fd, &cur_mm, false); mutex_unlock(&ctx->uring_lock); + + if (submitted != to_submit) + goto out; } if (flags & IORING_ENTER_GETEVENTS) { unsigned nr_events = 0; @@ -5148,6 +5151,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, } } +out: percpu_ref_put(&ctx->refs); out_fput: fdput(f); |