linux-next/io_uring
Jens Axboe 838b35bb6a io_uring/rw: disable IOCB_DIO_CALLER_COMP
If an application does O_DIRECT writes with io_uring and the file system
supports IOCB_DIO_CALLER_COMP, then completions of the dio write side is
done from the task_work that will post the completion event for said
write as well.

Whenever a dio write is done against a file, the inode i_dio_count is
elevated. This enables other callers to use inode_dio_wait() to wait for
previous writes to complete. If we defer the full dio completion to
task_work, we are dependent on that task_work being run before the
inode i_dio_count can be decremented.

If the same task that issues io_uring dio writes with
IOCB_DIO_CALLER_COMP performs a synchronous system call that calls
inode_dio_wait(), then we can deadlock as we're blocked sleeping on
the event to become true, but not processing the completions that will
result in the inode i_dio_count being decremented.

Until we can guarantee that this is the case, then disable the deferred
caller completions.

Fixes: 099ada2c87 ("io_uring/rw: add write support for IOCB_DIO_CALLER_COMP")
Reported-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-10-25 08:02:29 -06:00
..
advise.c io_uring: always go async for unsupported fadvise flags 2023-01-29 15:18:26 -07:00
advise.h io_uring: split out fadvise/madvise operations 2022-07-24 18:39:11 -06:00
alloc_cache.h io_uring/rsrc: consolidate node caching 2023-04-12 12:09:41 -06:00
cancel.c io_uring/cancel: wire up IORING_ASYNC_CANCEL_OP for sync cancel 2023-07-17 10:05:48 -06:00
cancel.h io_uring/cancel: support opcode based lookup and cancelation 2023-07-17 10:05:48 -06:00
epoll.c io_uring: undeprecate epoll_ctl support 2023-05-26 20:22:41 -06:00
epoll.h io_uring: move epoll handler to its own file 2022-07-24 18:39:11 -06:00
fdinfo.c io_uring/fdinfo: lock SQ thread while retrieving thread cpu/pid 2023-10-25 07:44:14 -06:00
fdinfo.h io_uring: move fdinfo helpers to its own file 2022-07-24 18:39:12 -06:00
filetable.c io_uring: add helpers to decode the fixed file file_ptr 2023-06-20 09:36:22 -06:00
filetable.h io_uring: add helpers to decode the fixed file file_ptr 2023-06-20 09:36:22 -06:00
fs.c io_uring/fs: remove sqe->rw_flags checking from LINKAT 2023-09-29 03:07:09 -06:00
fs.h io_uring: split out filesystem related operations 2022-07-24 18:39:11 -06:00
io_uring.c io_uring: fix crash with IORING_SETUP_NO_MMAP and invalid SQ ring address 2023-10-18 09:22:14 -06:00
io_uring.h io_uring: ensure io_lockdep_assert_cq_locked() handles disabled rings 2023-10-03 08:12:54 -06:00
io-wq.c io-wq: fully initialize wqe before calling cpuhp_state_add_instance_nocalls() 2023-10-05 14:11:18 -06:00
io-wq.h io_uring: break out of iowq iopoll on teardown 2023-09-07 09:02:27 -06:00
kbuf.c io_uring/kbuf: don't allow registered buffer rings on highmem pages 2023-10-03 08:12:28 -06:00
kbuf.h io_uring: add support for user mapped provided buffer ring 2023-04-03 07:14:21 -06:00
Makefile io_uring: add zc notification infrastructure 2022-07-24 18:41:06 -06:00
msg_ring.c io_uring: use io_file_from_index in io_msg_grab_file 2023-06-20 09:36:22 -06:00
msg_ring.h io_uring: get rid of double locking 2022-12-07 06:47:13 -07:00
net.c io_uring/net: fix iter retargeting for selected buf 2023-09-14 10:12:55 -06:00
net.h io_uring: Add KASAN support for alloc_caches 2023-04-03 07:16:14 -06:00
nop.c io_uring: kill extra io_uring_types.h includes 2022-07-24 18:39:14 -06:00
nop.h io_uring: move nop into its own file 2022-07-24 18:39:11 -06:00
notif.c io_uring/notif: add constant for ubuf_info flags 2023-04-15 14:21:04 -06:00
notif.h io_uring/notif: add constant for ubuf_info flags 2023-04-15 14:21:04 -06:00
opdef.c io_uring: Pass whole sqe to commands 2023-05-04 08:19:05 -06:00
opdef.h io_uring: Split io_issue_def struct 2023-01-29 15:17:41 -07:00
openclose.c io_uring: correct check for O_TMPFILE 2023-08-07 12:34:23 -06:00
openclose.h io_uring: split out fixed file installation and removal 2022-07-24 18:39:16 -06:00
poll.c io_uring: never overflow io_aux_cqe 2023-08-11 10:42:57 -06:00
poll.h io_uring: avoid indirect function calls for the hottest task_work 2023-06-02 08:55:37 -06:00
refs.h io_uring: make io_uring_types.h public 2022-07-24 18:39:14 -06:00
rsrc.c io_uring/rsrc: keep one global dummy_ubuf 2023-08-11 10:42:57 -06:00
rsrc.h io_uring/rsrc: Annotate struct io_mapped_ubuf with __counted_by 2023-08-17 19:14:47 -06:00
rw.c io_uring/rw: disable IOCB_DIO_CALLER_COMP 2023-10-25 08:02:29 -06:00
rw.h io_uring: avoid indirect function calls for the hottest task_work 2023-06-02 08:55:37 -06:00
slist.h io_uring: silence variable ‘prev’ set but not used warning 2023-03-09 10:10:58 -07:00
splice.c io_uring/splice: use fput() directly 2023-08-10 10:24:25 -06:00
splice.h io_uring: split out splice related operations 2022-07-24 18:39:11 -06:00
sqpoll.c io_uring: Don't set affinity on a dying sqpoll thread 2023-08-30 09:53:44 -06:00
sqpoll.h io_uring/sqpoll: fix io-wq affinity when IORING_SETUP_SQPOLL is used 2023-08-16 13:40:28 -06:00
statx.c io_uring: for requests that require async, force it 2023-01-29 15:18:26 -07:00
statx.h io_uring: move statx handling to its own file 2022-07-24 18:39:11 -06:00
sync.c io_uring: for requests that require async, force it 2023-01-29 15:18:26 -07:00
sync.h io_uring: split out fs related sync/fallocate functions 2022-07-24 18:39:11 -06:00
tctx.c io_uring: Add io_uring_setup flag to pre-register ring fd and never install it 2023-05-16 08:06:00 -06:00
tctx.h io_uring: simplify __io_uring_add_tctx_node 2022-10-07 12:25:30 -06:00
timeout.c io_uring: never overflow io_aux_cqe 2023-08-11 10:42:57 -06:00
timeout.h io_uring: remove unused return from io_disarm_next 2022-09-21 13:15:01 -06:00
uring_cmd.c io_uring: simplify big_cqe handling 2023-08-24 17:16:19 -06:00
uring_cmd.h io_uring: Remove unnecessary BUILD_BUG_ON 2023-05-04 08:19:05 -06:00
xattr.c io_uring: for requests that require async, force it 2023-01-29 15:18:26 -07:00
xattr.h io_uring: move xattr related opcodes to its own file 2022-07-24 18:39:11 -06:00