linux-stable.git/io_uring/msg_ring.c, branch v6.10

io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ring

2024-05-01T23:13:51+00:00

Move the posting outside the checking and locking, it's cleaner that
way.

Signed-off-by: Jens Axboe

io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it

2024-04-26T13:40:12+00:00

In io_msg_exec_remote(), ctx->submitter_task is read using READ_ONCE at
the beginning of the function, checked, and then re-read from
ctx->submitter_task, voiding all guarantees of the checks. Reuse the value
that was read by READ_ONCE to ensure the consistency of the task struct
throughout the function.

Signed-off-by: linke li 
Link: https://lore.kernel.org/r/tencent_F9B2296C93928D6F68FF0C95C33475C68209@qq.com
Signed-off-by: Jens Axboe

io_uring: use io_file_from_index in io_msg_grab_file

2023-06-20T15:36:22+00:00

Use io_file_from_index instead of open coding it.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20230620113235.920399-8-hch@lst.de
Signed-off-by: Jens Axboe

io_uring/msg_ring: let target know allocated index

2023-03-16T13:16:56+00:00

msg_ring requests transferring files support auto index selection via
IORING_FILE_INDEX_ALLOC, however they don't return the selected index
to the target ring and there is no other good way for the userspace to
know where is the receieved file.

Return the index for allocated slots and 0 otherwise, which is
consistent with other fixed file installing requests.

Cc: stable@vger.kernel.org # v6.0+
Fixes: e6130eba8a848 ("io_uring: add support for passing fixed file descriptors")
Signed-off-by: Pavel Begunkov 
Link: https://github.com/axboe/liburing/issues/809
Signed-off-by: Jens Axboe

io_uring/msg-ring: ensure flags passing works for task_work completions

2023-01-29T22:17:41+00:00

If the target ring is using IORING_SETUP_SINGLE_ISSUER and we're posting
a message from a different thread, then we need to ensure that the
fallback task_work that posts the CQE knwos about the flags passing as
well. If not we'll always be posting 0 as the flags.

Fixes: 3563d7ed58a5 ("io_uring/msg_ring: Pass custom flags to the cqe")
Signed-off-by: Jens Axboe

io_uring/msg_ring: Pass custom flags to the cqe

2023-01-29T22:17:40+00:00

This patch adds a new flag (IORING_MSG_RING_FLAGS_PASS) in the message
ring operations (IORING_OP_MSG_RING). This new flag enables the sender
to specify custom flags, which will be copied over to cqe->flags in the
receiving ring.  These custom flags should be specified using the
sqe->file_index field.

This mechanism provides additional flexibility when sending messages
between rings.

Signed-off-by: Breno Leitao 
Link: https://lore.kernel.org/r/20230103160507.617416-1-leitao@debian.org
Signed-off-by: Jens Axboe

io_uring/msg_ring: fix remote queue to disabled ring

2023-01-20T16:49:34+00:00

IORING_SETUP_R_DISABLED rings don't have the submitter task set, so
it's not always safe to use ->submitter_task. Disallow posting msg_ring
messaged to disabled rings. Also add task NULL check for loosy sync
around testing for IORING_SETUP_R_DISABLED.

Cc: stable@vger.kernel.org
Fixes: 6d043ee1164ca ("io_uring: do msg_ring in target task via tw")
Signed-off-by: Pavel Begunkov 
Signed-off-by: Jens Axboe

io_uring/msg_ring: fix flagging remote execution

2023-01-20T16:49:29+00:00

There is a couple of problems with queueing a tw in io_msg_ring_data()
for remote execution. First, once we queue it the target ring can
go away and so setting IORING_SQ_TASKRUN there is not safe. Secondly,
the userspace might not expect IORING_SQ_TASKRUN.

Extract a helper and uniformly use TWA_SIGNAL without TWA_SIGNAL_NO_IPI
tricks for now, just as it was done in the original patch.

Cc: stable@vger.kernel.org
Fixes: 6d043ee1164ca ("io_uring: do msg_ring in target task via tw")
Signed-off-by: Pavel Begunkov 
Signed-off-by: Jens Axboe

io_uring/msg_ring: fix missing lock on overflow for IOPOLL

2023-01-19T17:43:59+00:00

If the target ring is configured with IOPOLL, then we always need to hold
the target ring uring_lock before posting CQEs. We could just grab it
unconditionally, but since we don't expect many target rings to be of this
type, make grabbing the uring_lock conditional on the ring type.

Link: https://lore.kernel.org/io-uring/Y8krlYa52%2F0YGqkg@ip-172-31-85-199.ec2.internal/
Reported-by: Xingyuan Mo 
Signed-off-by: Jens Axboe

io_uring/msg_ring: move double lock/unlock helpers higher up

2023-01-19T16:01:27+00:00

In preparation for needing them somewhere else, move them and get rid of
the unused 'issue_flags' for the unlock side.

No functional changes in this patch.

Signed-off-by: Jens Axboe