diff options
| author | Caleb Sander Mateos <csander@purestorage.com> | 2026-01-05 14:05:41 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2026-01-12 11:21:38 -0700 |
| commit | bcd4c95737d15fa1a85152b8862dec146b11c214 (patch) | |
| tree | 01b7cac75bd189ba4e5535ca140e185e3b2ad0da /io_uring/io_uring.c | |
| parent | 7a8737e1132ff07ca225aa7a4008f87319b5b1ca (diff) | |
io_uring/msg_ring: drop unnecessary submitter_task checks
__io_msg_ring_data() checks that the target_ctx isn't
IORING_SETUP_R_DISABLED before calling io_msg_data_remote(), which calls
io_msg_remote_post(). So submitter_task can't be modified concurrently
with the read in io_msg_remote_post(). Additionally, submitter_task must
exist, as io_msg_data_remote() is only called for io_msg_need_remote(),
i.e. task_complete is set, which requires IORING_SETUP_DEFER_TASKRUN,
which in turn requires IORING_SETUP_SINGLE_ISSUER. And submitter_task is
assigned in io_uring_create() or io_register_enable_rings() before
enabling any IORING_SETUP_SINGLE_ISSUER io_ring_ctx.
Similarly, io_msg_send_fd() checks IORING_SETUP_R_DISABLED and
io_msg_need_remote() before calling io_msg_fd_remote(). submitter_task
therefore can't be modified concurrently with the read in
io_msg_fd_remote() and must be non-null.
io_register_enable_rings() can't run concurrently because it's called
from io_uring_register() -> __io_uring_register() with uring_lock held.
Thus, replace the READ_ONCE() and WRITE_ONCE() of submitter_task with
plain loads and stores. And remove the NULL checks of submitter_task in
io_msg_remote_post() and io_msg_fd_remote().
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/io_uring.c')
| -rw-r--r-- | io_uring/io_uring.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 559932b851ca..a1dd1540ab79 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3637,13 +3637,8 @@ static __cold int io_uring_create(struct io_ctx_config *config) } if (ctx->flags & IORING_SETUP_SINGLE_ISSUER - && !(ctx->flags & IORING_SETUP_R_DISABLED)) { - /* - * Unlike io_register_enable_rings(), don't need WRITE_ONCE() - * since ctx isn't yet accessible from other tasks - */ + && !(ctx->flags & IORING_SETUP_R_DISABLED)) ctx->submitter_task = get_task_struct(current); - } file = io_uring_get_file(ctx); if (IS_ERR(file)) { |