linux-stable.git/io_uring/rw.c, branch v6.1.78

io_uring/rw: ensure io->bytes_done is always initialized

2024-01-25T23:27:41+00:00

commit 0a535eddbe0dc1de4386046ab849f08aeb2f8faf upstream.

If IOSQE_ASYNC is set and we fail importing an iovec for a readv or
writev request, then we leave ->bytes_done uninitialized and hence the
eventual failure CQE posted can potentially have a random res value
rather than the expected -EINVAL.

Setup ->bytes_done before potentially failing, so we have a consistent
value if we fail the request early.

Cc: stable@vger.kernel.org
Reported-by: xingwei lee 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

io_uring: kiocb_done() should not trust ->ki_pos if ->{read,write}_iter() failed

2023-11-08T13:11:02+00:00

[ Upstream commit 1939316bf988f3e49a07d9c4dd6f660bf4daa53d ]

->ki_pos value is unreliable in such cases.  For an obvious example,
consider O_DSYNC write - we feed the data to page cache and start IO,
then we make sure it's completed.  Update of ->ki_pos is dealt with
by the first part; failure in the second ends up with negative value
returned _and_ ->ki_pos left advanced as if sync had been successful.
In the same situation write(2) does not advance the file position
at all.

Reviewed-by: Christian Brauner 
Reviewed-by: Jens Axboe 
Signed-off-by: Al Viro 
Signed-off-by: Sasha Levin

use less confusing names for iov_iter direction initializers

2023-02-09T10:28:04+00:00

[ Upstream commit de4eda9de2d957ef2d6a8365a01e26a435e958cb ]

READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro 
Stable-dep-of: 6dd88fd59da8 ("vhost-scsi: unbreak any layout for response")
Signed-off-by: Sasha Levin

io_uring: lock overflowing for IOPOLL

2023-01-18T10:58:33+00:00

commit 544d163d659d45a206d8929370d5a2984e546cb7 upstream.

syzbot reports an issue with overflow filling for IOPOLL:

WARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734
CPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0
Workqueue: events_unbound io_ring_exit_work
Call trace:
 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734
 io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773
 io_fill_cqe_req io_uring/io_uring.h:168 [inline]
 io_do_iopoll+0x474/0x62c io_uring/rw.c:1065
 io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513
 io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056
 io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869
 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
 worker_thread+0x340/0x610 kernel/workqueue.c:2436
 kthread+0x12c/0x158 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863

There is no real problem for normal IOPOLL as flush is also called with
uring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL,
for which __io_cqring_overflow_flush() happens from the CQ waiting path.

Reported-and-tested-by: syzbot+6805087452d72929404e@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Pavel Begunkov 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

io_uring: remove iopoll spinlock

2022-12-31T12:33:12+00:00

commit 2dac1a159216b39ced8d78dba590c5d2f4249586 upstream.

This reverts commit 2ccc92f4effcfa1c51c4fcf1e34d769099d3cad4

io_req_complete_post() should now behave well even in case of IOPOLL, we
can remove completion_lock locking.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/7e171c8b530656b14a671c59100ca260e46e7f2a.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

io_uring: add completion locking for iopoll

2022-12-31T12:33:11+00:00

commit 2ccc92f4effcfa1c51c4fcf1e34d769099d3cad4 upstream.

There are pieces of code that may allow iopoll to race filling cqes,
temporarily add spinlocking around posting events.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/84d86b5c117feda075471c5c9e65208e0dccf5d0.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

io_uring/rw: remove leftover debug statement

2022-10-16T23:24:10+00:00

This debug statement was never meant to go into the upstream release,
kill it off before it ends up in a release. It was just part of the
testing for the initial version of the patch.

Fixes: 2ec33a6c3cca ("io_uring/rw: ensure kiocb_end_write() is always called")
Signed-off-by: Jens Axboe

io_uring/rw: ensure kiocb_end_write() is always called

2022-10-12T22:30:56+00:00

A previous commit moved the notifications and end-write handling, but
it is now missing a few spots where we also want to call both of those.
Without that, we can potentially be missing file notifications, and
more importantly, have an imbalance in the super_block writers sem
accounting.

Fixes: b000145e9907 ("io_uring/rw: defer fsnotify calls to task context")
Reported-by: Dave Chinner 
Link: https://lore.kernel.org/all/20221010050319.GC2703033@dread.disaster.area/
Signed-off-by: Jens Axboe

io_uring: local variable rw shadows outer variable in io_write