diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-08-25 20:51:39 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-08-27 09:23:11 -0600 |
| commit | b18a1a4574d2d15f1b0c84658d4549ccbf241fee (patch) | |
| tree | ca582efb2cfd61060de9cf4cc2155ecc2708fdde /fs/io_uring.c | |
| parent | 9a10867ae54e02a0f204d2eebea5a446fb7a86f9 (diff) | |
io_uring: clarify io_req_task_cancel() locking
It's too easy to forget and misjudge about synchronisation in
io_req_task_cancel(), add a comment clarifying it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/71099083835f983a1fd73d5a3da6391924da8300.1629920396.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 5059049da242..09194f7276ba 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2168,7 +2168,7 @@ static void io_req_task_cancel(struct io_kiocb *req, bool *locked) { struct io_ring_ctx *ctx = req->ctx; - /* ctx is guaranteed to stay alive while we hold uring_lock */ + /* not needed for normal modes, but SQPOLL depends on it */ io_tw_lock(ctx, locked); io_req_complete_failed(req, req->result); } @@ -2177,7 +2177,6 @@ static void io_req_task_submit(struct io_kiocb *req, bool *locked) { struct io_ring_ctx *ctx = req->ctx; - /* ctx stays valid until unlock, even if we drop all ours ctx->refs */ io_tw_lock(ctx, locked); /* req->task == current here, checking PF_EXITING is safe */ if (likely(!(req->task->flags & PF_EXITING))) |