Commit Graph

84 Commits

Author SHA1 Message Date
Pavel Begunkov
6e6b8c6212 io_uring/rw: avoid punting to io-wq directly
kiocb_done() should care to specifically redirecting requests to io-wq.
Remove the hopping to tw to then queue an io-wq, return -EAGAIN and let
the core code io_uring handle offloading.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/413564e550fe23744a970e1783dfa566291b0e6f.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
Jens Axboe
2a975d426c io_uring/rw: don't allow multishot reads without NOWAIT support
Supporting multishot reads requires support for NOWAIT, as the
alternative would be always having io-wq execute the work item whenever
the poll readiness triggered. Any fast file type will have NOWAIT
support (eg it understands both O_NONBLOCK and IOCB_NOWAIT). If the
given file type does not, then simply resort to single shot execution.

Cc: stable@vger.kernel.org
Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-01 11:41:50 -06:00
Jens Axboe
0a3737db84 io_uring/rw: return IOU_ISSUE_SKIP_COMPLETE for multishot retry
If read multishot is being invoked from the poll retry handler, then we
should return IOU_ISSUE_SKIP_COMPLETE rather than -EAGAIN. If not, then
a CQE will be posted with -EAGAIN rather than triggering the retry when
the file is flagged as readable again.

Cc: stable@vger.kernel.org
Reported-by: Sargun Dhillon <sargun@meta.com>
Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-12 08:29:47 -06:00
Pavel Begunkov
e0e4ab52d1 io_uring: refactor DEFER_TASKRUN multishot checks
We disallow DEFER_TASKRUN multishots from running by io-wq, which is
checked by individual opcodes in the issue path. We can consolidate all
it in io_wq_submit_work() at the same time moving the checks out of the
hot path.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e492f0f11588bb5aa11d7d24e6f53b7c7628afdb.1709905727.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-08 07:58:23 -07:00
Jens Axboe
186daf2385 io_uring/kbuf: rename REQ_F_PARTIAL_IO to REQ_F_BL_NO_RECYCLE
We only use the flag for this purpose, so rename it accordingly. This
further prevents various other use cases of it, keeping it clean and
consistent. Then we can also check it in one spot, when it's being
attempted recycled, and remove some dead code in io_kbuf_recycle_ring().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-08 07:56:27 -07:00
Pavel Begunkov
70581dcd06 io_uring: fix mshot read defer taskrun cqe posting
We can't post CQEs from io-wq with DEFER_TASKRUN set, normal completions
are handled but aux should be explicitly disallowed by opcode handlers.

Cc: stable@vger.kernel.org
Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6fb7cba6f5366da25f4d3eb95273f062309d97fa.1709740837.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-07 06:30:33 -07:00
Kuniyuki Iwashima
3fb1764c6b io_uring: Don't include af_unix.h.
Changes to AF_UNIX trigger rebuild of io_uring, but io_uring does
not use AF_UNIX anymore.

Let's not include af_unix.h and instead include necessary headers.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240212234236.63714-1-kuniyu@amazon.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-12 19:02:11 -07:00
Jens Axboe
949249e25f io_uring/rw: remove dead file == NULL check
Any read/write opcode has needs_file == true, which means that we
would've failed the request long before reaching the issue stage if we
didn't successfully assign a file. This check has been dead forever,
and is really a leftover from generic code.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08 13:27:06 -07:00
Jens Axboe
95041b93e9 io_uring: add io_file_can_poll() helper
This adds a flag to avoid dipping dereferencing file and then f_op to
figure out if the file has a poll handler defined or not. We generally
call this at least twice for networked workloads, and if using ring
provided buffers, we do it on every buffer selection. Particularly the
latter is troublesome, as it's otherwise a very fast operation.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08 13:27:06 -07:00
Jens Axboe
c79f52f065 io_uring/rw: ensure poll based multishot read retries appropriately
io_read_mshot() always relies on poll triggering retries, and this works
fine as long as we do a retry per size of the buffer being read. The
buffer size is given by the size of the buffer(s) in the given buffer
group ID.

But if we're reading less than what is available, then we don't always
get to read everything that is available. For example, if the buffers
available are 32 bytes and we have 64 bytes to read, then we'll
correctly read the first 32 bytes and then wait for another poll trigger
before we attempt the next read. This next poll trigger may never
happen, in which case we just sit forever and never make progress, or it
may trigger at some point in the future, and now we're just delivering
the available data much later than we should have.

io_read_mshot() could do retries itself, but that is wasteful as we'll
be going through all of __io_read() again, and most likely in vain.
Rather than do that, bump our poll reference count and have
io_poll_check_events() do one more loop and check with vfs_poll() if we
have more data to read. If we do, io_read_mshot() will get invoked again
directly and we'll read the next chunk.

io_poll_multishot_retry() must only get called from inside
io_poll_issue(), which is our multishot retry handler, as we know we
already "own" the request at this point.

Cc: stable@vger.kernel.org
Link: https://github.com/axboe/liburing/issues/1041
Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-28 20:37:11 -07:00
Jens Axboe
fe80eb15de io_uring/rw: cleanup io_rw_done()
This originally came from the aio side, and it's laid out rather oddly.
The common case here is that we either get -EIOCBQUEUED from submitting
an async request, or that we complete the request correctly with the
given number of bytes. Handling the odd internal restart error codes
is not a common operation.

Lay it out a bit more optimally that better explains the normal flow,
and switch to avoiding the indirect call completely as this is our
kiocb and we know the completion handler can only be one of two
possible variants. While at it, move it to where it belongs in the
file, with fellow end IO helpers.

Outside of being easier to read, this also reduces the text size of the
function by 24 bytes for me on arm64.

Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-10 11:46:48 -07:00
Jens Axboe
0a535eddbe io_uring/rw: ensure io->bytes_done is always initialized
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 <xrivendell7@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-21 08:49:18 -07:00
Pavel Begunkov
b66509b849 io_uring: split out cmd api into a separate header
linux/io_uring.h is slowly becoming a rubbish bin where we put
anything exposed to other subsystems. For instance, the task exit
hooks and io_uring cmd infra are completely orthogonal and don't need
each other's definitions. Start cleaning it up by splitting out all
command bits into a new header file.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7ec50bae6e21f371d3850796e716917fc141225a.1701391955.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-12 07:42:52 -07:00
Dylan Yudaken
e53759298a io_uring: do not clamp read length for multishot read
When doing a multishot read, the code path reuses the old read
paths. However this breaks an assumption built into those paths,
namely that struct io_rw::len is available for reuse by __io_import_iovec.

For multishot this results in len being set for the first receive
call, and then subsequent calls are clamped to that buffer length
incorrectly.

Instead keep len as zero after recycling buffers, to reuse the full
buffer size of the next selected buffer.

Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Dylan Yudaken <dyudaken@gmail.com>
Link: https://lore.kernel.org/r/20231106203909.197089-4-dyudaken@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-06 13:41:58 -07:00
Dylan Yudaken
49fbe99486 io_uring: do not allow multishot read to set addr or len
For addr: this field is not used, since buffer select is forced.
But by forcing it to be zero it leaves open future uses of the field.

len is actually usable, you could imagine that you want to receive
multishot up to a certain length.
However right now this is not how it is implemented, and it seems
safer to force this to be zero.

Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Dylan Yudaken <dyudaken@gmail.com>
Link: https://lore.kernel.org/r/20231106203909.197089-3-dyudaken@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-06 13:41:58 -07:00
Jens Axboe
f688944cfb io_uring/rw: add separate prep handler for fixed read/write
Rather than sprinkle opcode checks in the generic read/write prep handler,
have a separate prep handler for the vectored readv/writev operation.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-06 07:43:16 -07:00
Jens Axboe
0e984ec88d io_uring/rw: add separate prep handler for readv/writev
Rather than sprinkle opcode checks in the generic read/write prep handler,
have a separate prep handler for the vectored readv/writev operation.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-06 07:41:17 -07:00
Jens Axboe
0df96fb71a io_uring/rw: don't attempt to allocate async data if opcode doesn't need it
The new read multishot method doesn't need to allocate async data ever,
as it doesn't do vectored IO and it must only be used with provided
buffers. While it doesn't have ->prep_async() set, it also sets
->async_size to 0, which is different from any other read/write type we
otherwise support.

If it's used on a file type that isn't pollable, we do try and allocate
this async data, and then try and use that data. But since we passed in
a size of 0 for the data, we get a NULL back on data allocation. We then
proceed to dereference that to copy state, and that obviously won't end
well.

Add a check in io_setup_async_rw() for this condition, and avoid copying
state. Also add a check for whether or not buffer selection is specified
in prep while at it.

Fixes: fc68fcda04 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218101
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-03 09:31:21 -06:00
Linus Torvalds
ffa059b262 for-6.7/io_uring-2023-10-30
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Merge tag 'for-6.7/io_uring-2023-10-30' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:
 "This contains the core io_uring updates, of which there are not many,
  and adds support for using WAITID through io_uring and hence not
  needing to block on these kinds of events.

  Outside of that, tweaks to the legacy provided buffer handling and
  some cleanups related to cancelations for uring_cmd support"

* tag 'for-6.7/io_uring-2023-10-30' of git://git.kernel.dk/linux:
  io_uring/poll: use IOU_F_TWQ_LAZY_WAKE for wakeups
  io_uring/kbuf: Use slab for struct io_buffer objects
  io_uring/kbuf: Allow the full buffer id space for provided buffers
  io_uring/kbuf: Fix check of BID wrapping in provided buffers
  io_uring/rsrc: cleanup io_pin_pages()
  io_uring: cancelable uring_cmd
  io_uring: retain top 8bits of uring_cmd flags for kernel internal use
  io_uring: add IORING_OP_WAITID support
  exit: add internal include file with helpers
  exit: add kernel_waitid_prepare() helper
  exit: move core of do_wait() into helper
  exit: abstract out should_wake helper for child_wait_callback()
  io_uring/rw: add support for IORING_OP_READ_MULTISHOT
  io_uring/rw: mark readv/writev as vectored in the opcode definition
  io_uring/rw: split io_read() into a helper
2023-11-01 11:09:19 -10:00
Linus Torvalds
d1b0949f23 assorted fixes all over the place
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Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc filesystem fixes from Al Viro:
 "Assorted fixes all over the place: literally nothing in common, could
  have been three separate pull requests.

  All are simple regression fixes, but not for anything from this cycle"

* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ceph_wait_on_conflict_unlink(): grab reference before dropping ->d_lock
  io_uring: kiocb_done() should *not* trust ->ki_pos if ->{read,write}_iter() failed
  sparc32: fix a braino in fault handling in csum_and_copy_..._user()
2023-10-27 16:44:58 -10:00
Al Viro
1939316bf9 io_uring: kiocb_done() should *not* trust ->ki_pos if ->{read,write}_iter() failed
->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 <brauner@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-10-27 20:14:11 -04:00
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
Jens Axboe
fc68fcda04 io_uring/rw: add support for IORING_OP_READ_MULTISHOT
This behaves like IORING_OP_READ, except:

1) It only supports pollable files (eg pipes, sockets, etc). Note that
   for sockets, you probably want to use recv/recvmsg with multishot
   instead.

2) It supports multishot mode, meaning it will repeatedly trigger a
   read and fill a buffer when data is available. This allows similar
   use to recv/recvmsg but on non-sockets, where a single request will
   repeatedly post a CQE whenever data is read from it.

3) Because of #2, it must be used with provided buffers. This is
   uniformly true across any request type that supports multishot and
   transfers data, with the reason being that it's obviously not
   possible to pass in a single buffer for the data, as multiple reads
   may very well trigger before an application has a chance to process
   previous CQEs and the data passed from them.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-21 12:02:30 -06:00
Jens Axboe
d2d778fbf9 io_uring/rw: mark readv/writev as vectored in the opcode definition
This is cleaner than gating on the opcode type, particularly as more
read/write type opcodes may be added.

Then we can use that for the data import, and for __io_read() on
whether or not we need to copy state.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-21 12:00:46 -06:00
Jens Axboe
a08d195b58 io_uring/rw: split io_read() into a helper
Add __io_read() which does the grunt of the work, leaving the completion
side to the new io_read(). No functional changes in this patch.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-21 12:00:41 -06:00
Linus Torvalds
c1b7fcf3f6 for-6.6/io_uring-2023-08-28
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Merge tag 'for-6.6/io_uring-2023-08-28' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:
 "Fairly quiet round in terms of features, mostly just improvements all
  over the map for existing code. In detail:

   - Initial support for socket operations through io_uring. Latter half
     of this will likely land with the 6.7 kernel, then allowing things
     like get/setsockopt (Breno)

   - Cleanup of the cancel code, and then adding support for canceling
     requests with the opcode as the key (me)

   - Improvements for the io-wq locking (me)

   - Fix affinity setting for SQPOLL based io-wq (me)

   - Remove the io_uring userspace code. These were added initially as
     copies from liburing, but all of them have since bitrotted and are
     way out of date at this point. Rather than attempt to keep them in
     sync, just get rid of them. People will have liburing available
     anyway for these examples. (Pavel)

   - Series improving the CQ/SQ ring caching (Pavel)

   - Misc fixes and cleanups (Pavel, Yue, me)"

* tag 'for-6.6/io_uring-2023-08-28' of git://git.kernel.dk/linux: (47 commits)
  io_uring: move iopoll ctx fields around
  io_uring: move multishot cqe cache in ctx
  io_uring: separate task_work/waiting cache line
  io_uring: banish non-hot data to end of io_ring_ctx
  io_uring: move non aligned field to the end
  io_uring: add option to remove SQ indirection
  io_uring: compact SQ/CQ heads/tails
  io_uring: force inline io_fill_cqe_req
  io_uring: merge iopoll and normal completion paths
  io_uring: reorder cqring_flush and wakeups
  io_uring: optimise extra io_get_cqe null check
  io_uring: refactor __io_get_cqe()
  io_uring: simplify big_cqe handling
  io_uring: cqe init hardening
  io_uring: improve cqe !tracing hot path
  io_uring/rsrc: Annotate struct io_mapped_ubuf with __counted_by
  io_uring/sqpoll: fix io-wq affinity when IORING_SETUP_SQPOLL is used
  io_uring: simplify io_run_task_work_sig return
  io_uring/rsrc: keep one global dummy_ubuf
  io_uring: never overflow io_aux_cqe
  ...
2023-08-29 20:11:33 -07:00
Linus Torvalds
6016fc9162 New code for 6.6:
* Make large writes to the page cache fill sparse parts of the cache
    with large folios, then use large memcpy calls for the large folio.
  * Track the per-block dirty state of each large folio so that a
    buffered write to a single byte on a large folio does not result in a
    (potentially) multi-megabyte writeback IO.
  * Allow some directio completions to be performed in the initiating
    task's context instead of punting through a workqueue.  This will
    reduce latency for some io_uring requests.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'iomap-6.6-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap updates from Darrick Wong:
 "We've got some big changes for this release -- I'm very happy to be
  landing willy's work to enable large folios for the page cache for
  general read and write IOs when the fs can make contiguous space
  allocations, and Ritesh's work to track sub-folio dirty state to
  eliminate the write amplification problems inherent in using large
  folios.

  As a bonus, io_uring can now process write completions in the caller's
  context instead of bouncing through a workqueue, which should reduce
  io latency dramatically. IOWs, XFS should see a nice performance bump
  for both IO paths.

  Summary:

   - Make large writes to the page cache fill sparse parts of the cache
     with large folios, then use large memcpy calls for the large folio.

   - Track the per-block dirty state of each large folio so that a
     buffered write to a single byte on a large folio does not result in
     a (potentially) multi-megabyte writeback IO.

   - Allow some directio completions to be performed in the initiating
     task's context instead of punting through a workqueue. This will
     reduce latency for some io_uring requests"

* tag 'iomap-6.6-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (26 commits)
  iomap: support IOCB_DIO_CALLER_COMP
  io_uring/rw: add write support for IOCB_DIO_CALLER_COMP
  fs: add IOCB flags related to passing back dio completions
  iomap: add IOMAP_DIO_INLINE_COMP
  iomap: only set iocb->private for polled bio
  iomap: treat a write through cache the same as FUA
  iomap: use an unsigned type for IOMAP_DIO_* defines
  iomap: cleanup up iomap_dio_bio_end_io()
  iomap: Add per-block dirty state tracking to improve performance
  iomap: Allocate ifs in ->write_begin() early
  iomap: Refactor iomap_write_delalloc_punch() function out
  iomap: Use iomap_punch_t typedef
  iomap: Fix possible overflow condition in iomap_write_delalloc_scan
  iomap: Add some uptodate state handling helpers for ifs state bitmap
  iomap: Drop ifs argument from iomap_set_range_uptodate()
  iomap: Rename iomap_page to iomap_folio_state and others
  iomap: Copy larger chunks from userspace
  iomap: Create large folios in the buffered write path
  filemap: Allow __filemap_get_folio to allocate large folios
  filemap: Add fgf_t typedef
  ...
2023-08-28 11:59:52 -07:00
Pavel Begunkov
ec26c225f0 io_uring: merge iopoll and normal completion paths
io_do_iopoll() and io_submit_flush_completions() are pretty similar,
both filling CQEs and then free a list of requests. Don't duplicate it
and make iopoll use __io_submit_flush_completions(), which also helps
with inlining and other optimisations.

For that, we need to first find all completed iopoll requests and splice
them from the iopoll list and then pass it down. This adds one extra
list traversal, which should be fine as requests will stay hot in cache.

CQ locking is already conditional, introduce ->lockless_cq and skip
locking for IOPOLL as it's protected by ->uring_lock.

We also add a wakeup optimisation for IOPOLL to __io_cq_unlock_post(),
so it works just like io_cqring_ev_posted_iopoll().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3840473f5e8a960de35b77292026691880f6bdbc.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Pavel Begunkov
54927baf6c io_uring: reorder cqring_flush and wakeups
Unlike in the past, io_commit_cqring_flush() doesn't do anything that
may need io_cqring_wake() to be issued after, all requests it completes
will go via task_work. Do io_commit_cqring_flush() after
io_cqring_wake() to clean up __io_cq_unlock_post().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ed32dcfeec47e6c97bd6b18c152ddce5b218403f.1692916914.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-24 17:16:19 -06:00
Amir Goldstein
e484fd73f4 io_uring: use kiocb_{start,end}_write() helpers
Use helpers instead of the open coded dance to silence lockdep warnings.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-5-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21 17:27:26 +02:00
Amir Goldstein
a370167fe5 io_uring: rename kiocb_end_write() local helper
This helper does not take a kiocb as input and we want to create a
common helper by that name that takes a kiocb as input.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-2-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21 17:27:25 +02:00
Pavel Begunkov
00b0db5624 io_uring: open code io_fill_cqe_req()
io_fill_cqe_req() is only called from one place, open code it, and
rename __io_fill_cqe_req().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f432ce75bb1c94cadf0bd2add4d6aa510bd1fb36.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11 10:42:57 -06:00
Jens Axboe
099ada2c87 io_uring/rw: add write support for IOCB_DIO_CALLER_COMP
If the filesystem dio handler understands IOCB_DIO_CALLER_COMP, we'll
get a kiocb->ki_complete() callback with kiocb->dio_complete set. In
that case, rather than complete the IO directly through task_work, queue
up an intermediate task_work handler that first processes this callback
and then immediately completes the request.

For XFS, this avoids a punt through a workqueue, which is a lot less
efficient and adds latency to lower queue depth (or sync) O_DIRECT
writes.

Only do this for non-polled IO, as polled IO doesn't need this kind
of deferral as it always completes within the task itself. This then
avoids a check for deferral in the polled IO completion handler.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-01 17:32:45 -06:00
Christoph Hellwig
8487f083c6 io_uring: return REQ_F_ flags from io_file_get_flags
Two of the three callers want them, so return the more usual format,
and shift into the FFS_ form only for the fixed file table.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230620113235.920399-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-20 09:36:22 -06:00
Christoph Hellwig
3beed235d1 io_uring: remove io_req_ffs_set
Just checking the flag directly makes it a lot more obvious what is
going on here.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230620113235.920399-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-20 09:36:22 -06:00
Jens Axboe
c92fcfc2ba io_uring: avoid indirect function calls for the hottest task_work
We use task_work for a variety of reasons, but doing completions or
triggering rety after poll are by far the hottest two. Use the indirect
funtion call wrappers to avoid the indirect function call if
CONFIG_RETPOLINE is set.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-02 08:55:37 -06:00
Linus Torvalds
9dd6956b38 for-6.4/block-2023-04-21
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Merge tag 'for-6.4/block-2023-04-21' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - drbd patches, bringing us closer to unifying the out-of-tree version
   and the in tree one (Andreas, Christoph)

 - support for auto-quiesce for the s390 dasd driver (Stefan)

 - MD pull request via Song:
      - md/bitmap: Optimal last page size (Jon Derrick)
      - Various raid10 fixes (Yu Kuai, Li Nan)
      - md: add error_handlers for raid0 and linear (Mariusz Tkaczyk)

 - NVMe pull request via Christoph:
      - Drop redundant pci_enable_pcie_error_reporting (Bjorn Helgaas)
      - Validate nvmet module parameters (Chaitanya Kulkarni)
      - Fence TCP socket on receive error (Chris Leech)
      - Fix async event trace event (Keith Busch)
      - Minor cleanups (Chaitanya Kulkarni, zhenwei pi)
      - Fix and cleanup nvmet Identify handling (Damien Le Moal,
        Christoph Hellwig)
      - Fix double blk_mq_complete_request race in the timeout handler
        (Lei Yin)
      - Fix irq locking in nvme-fcloop (Ming Lei)
      - Remove queue mapping helper for rdma devices (Sagi Grimberg)

 - use structured request attribute checks for nbd (Jakub)

 - fix blk-crypto race conditions between keyslot management (Eric)

 - add sed-opal support for reading read locking range attributes
   (Ondrej)

 - make fault injection configurable for null_blk (Akinobu)

 - clean up the request insertion API (Christoph)

 - clean up the queue running API (Christoph)

 - blkg config helper cleanups (Tejun)

 - lazy init support for blk-iolatency (Tejun)

 - various fixes and tweaks to ublk (Ming)

 - remove hybrid polling. It hasn't really been useful since we got
   async polled IO support, and these days we don't support sync polled
   IO at all (Keith)

 - misc fixes, cleanups, improvements (Zhong, Ondrej, Colin, Chengming,
   Chaitanya, me)

* tag 'for-6.4/block-2023-04-21' of git://git.kernel.dk/linux: (118 commits)
  nbd: fix incomplete validation of ioctl arg
  ublk: don't return 0 in case of any failure
  sed-opal: geometry feature reporting command
  null_blk: Always check queue mode setting from configfs
  block: ublk: switch to ioctl command encoding
  blk-mq: fix the blk_mq_add_to_requeue_list call in blk_kick_flush
  block, bfq: Fix division by zero error on zero wsum
  fault-inject: fix build error when FAULT_INJECTION_CONFIGFS=y and CONFIGFS_FS=m
  block: store bdev->bd_disk->fops->submit_bio state in bdev
  block: re-arrange the struct block_device fields for better layout
  md/raid5: remove unused working_disks variable
  md/raid10: don't call bio_start_io_acct twice for bio which experienced read error
  md/raid10: fix memleak of md thread
  md/raid10: fix memleak for 'conf->bio_split'
  md/raid10: fix leak of 'r10bio->remaining' for recovery
  md/raid10: don't BUG_ON() in raise_barrier()
  md: fix soft lockup in status_resync
  md: add error_handlers for raid0 and linear
  md: Use optimal I/O size for last bitmap page
  md: Fix types in sb writer
  ...
2023-04-26 12:52:58 -07:00
Linus Torvalds
5b9a7bb72f for-6.4/io_uring-2023-04-21
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Merge tag 'for-6.4/io_uring-2023-04-21' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:

 - Cleanup of the io-wq per-node mapping, notably getting rid of it so
   we just have a single io_wq entry per ring (Breno)

 - Followup to the above, move accounting to io_wq as well and
   completely drop struct io_wqe (Gabriel)

 - Enable KASAN for the internal io_uring caches (Breno)

 - Add support for multishot timeouts. Some applications use timeouts to
   wake someone waiting on completion entries, and this makes it a bit
   easier to just have a recurring timer rather than needing to rearm it
   every time (David)

 - Support archs that have shared cache coloring between userspace and
   the kernel, and hence have strict address requirements for mmap'ing
   the ring into userspace. This should only be parisc/hppa. (Helge, me)

 - XFS has supported O_DIRECT writes without needing to lock the inode
   exclusively for a long time, and ext4 now supports it as well. This
   is true for the common cases of not extending the file size. Flag the
   fs as having that feature, and utilize that to avoid serializing
   those writes in io_uring (me)

 - Enable completion batching for uring commands (me)

 - Revert patch adding io_uring restriction to what can be GUP mapped or
   not. This does not belong in io_uring, as io_uring isn't really
   special in this regard. Since this is also getting in the way of
   cleanups and improvements to the GUP code, get rid of if (me)

 - A few series greatly reducing the complexity of registered resources,
   like buffers or files. Not only does this clean up the code a lot,
   the simplified code is also a LOT more efficient (Pavel)

 - Series optimizing how we wait for events and run task_work related to
   it (Pavel)

 - Fixes for file/buffer unregistration with DEFER_TASKRUN (Pavel)

 - Misc cleanups and improvements (Pavel, me)

* tag 'for-6.4/io_uring-2023-04-21' of git://git.kernel.dk/linux: (71 commits)
  Revert "io_uring/rsrc: disallow multi-source reg buffers"
  io_uring: add support for multishot timeouts
  io_uring/rsrc: disassociate nodes and rsrc_data
  io_uring/rsrc: devirtualise rsrc put callbacks
  io_uring/rsrc: pass node to io_rsrc_put_work()
  io_uring/rsrc: inline io_rsrc_put_work()
  io_uring/rsrc: add empty flag in rsrc_node
  io_uring/rsrc: merge nodes and io_rsrc_put
  io_uring/rsrc: infer node from ctx on io_queue_rsrc_removal
  io_uring/rsrc: remove unused io_rsrc_node::llist
  io_uring/rsrc: refactor io_queue_rsrc_removal
  io_uring/rsrc: simplify single file node switching
  io_uring/rsrc: clean up __io_sqe_buffers_update()
  io_uring/rsrc: inline switch_start fast path
  io_uring/rsrc: remove rsrc_data refs
  io_uring/rsrc: fix DEFER_TASKRUN rsrc quiesce
  io_uring/rsrc: use wq for quiescing
  io_uring/rsrc: refactor io_rsrc_ref_quiesce
  io_uring/rsrc: remove io_rsrc_node::done
  io_uring/rsrc: use nospec'ed indexes
  ...
2023-04-26 12:40:31 -07:00
Pavel Begunkov
8751d15426 io_uring: reduce scheduling due to tw
Every task_work will try to wake the task to be executed, which causes
excessive scheduling and additional overhead. For some tw it's
justified, but others won't do much but post a single CQE.

When a task waits for multiple cqes, every such task_work will wake it
up. Instead, the task may give a hint about how many cqes it waits for,
io_req_local_work_add() will compare against it and skip wake ups
if #cqes + #tw is not enough to satisfy the waiting condition. Task_work
that uses the optimisation should be simple enough and never post more
than one CQE. It's also ignored for non DEFER_TASKRUN rings.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d2b77e99d1e86624d8a69f7037d764b739dcd225.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:23:28 -06:00
Pavel Begunkov
a282967c84 io_uring: encapsulate task_work state
For task works we're passing around a bool pointer for whether the
current ring is locked or not, let's wrap it in a structure, that
will make it more opaque preventing abuse and will also help us
to pass more info in the future if needed.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1ecec9483d58696e248d1bfd52cf62b04442df1d.1679931367.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:15 -06:00
Jens Axboe
95e49cf837 iov_iter: add iter_iov_addr() and iter_iov_len() helpers
These just return the address and length of the current iovec segment
in the iterator. Convert existing iov_iter_iovec() users to use them
instead of getting a copy of the current vec.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-30 08:12:29 -06:00
Jens Axboe
de4f5fed3f iov_iter: add iter_iovec() helper
This returns a pointer to the current iovec entry in the iterator. Only
useful with ITER_IOVEC right now, but it prepares us to treat ITER_UBUF
and ITER_IOVEC identically for the first segment.

Rename struct iov_iter->iov to iov_iter->__iov to find any potentially
troublesome spots, and also to prevent anyone from adding new code that
accesses iter->iov directly.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-30 08:12:29 -06:00
Keith Busch
54bdd67d0f blk-mq: remove hybrid polling
io_uring provides the only way user space can poll completions, and that
always sets BLK_POLL_NOSLEEP. This effectively makes hybrid polling dead
code, so remove it and everything supporting it.

Hybrid polling was effectively killed off with 9650b453a3, "block:
ignore RWF_HIPRI hint for sync dio", but still potentially reachable
through io_uring until d729cf9acb, "io_uring: don't sleep when
polling for I/O", but hybrid polling probably should not have been
reachable through that async interface from the beginning.

Fixes: 9650b453a3 ("block: ignore RWF_HIPRI hint for sync dio")
Fixes: d729cf9acb ("io_uring: don't sleep when polling for I/O")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20230320194926.3353144-1-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-20 15:30:03 -06:00
Linus Torvalds
c1ef500307 for-6.3/iter-ubuf-2023-02-16
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Merge tag 'for-6.3/iter-ubuf-2023-02-16' of git://git.kernel.dk/linux

Pull io_uring ITER_UBUF conversion from Jens Axboe:
 "Since we now have ITER_UBUF available, switch to using it for single
  ranges as it's more efficient than ITER_IOVEC for that"

* tag 'for-6.3/iter-ubuf-2023-02-16' of git://git.kernel.dk/linux:
  block: use iter_ubuf for single range
  iov_iter: move iter_ubuf check inside restore WARN
  io_uring: use iter_ubuf for single range imports
  io_uring: switch network send/recv to ITER_UBUF
  iov: add import_ubuf()
2023-02-20 14:03:57 -08:00
Breno Leitao
f30bd4d038 io_uring: Split io_issue_def struct
This patch removes some "cold" fields from `struct io_issue_def`.

The plan is to keep only highly used fields into `struct io_issue_def`, so,
it may be hot in the cache. The hot fields are basically all the bitfields
and the callback functions for .issue and .prep.

The other less frequently used fields are now located in a secondary and
cold struct, called `io_cold_def`.

This is the size for the structs:

Before: io_issue_def = 56 bytes
After: io_issue_def = 24 bytes; io_cold_def = 40 bytes

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20230112144411.2624698-2-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Breno Leitao
a7dd27828b io_uring: Rename struct io_op_def
The current io_op_def struct is becoming huge and the name is a bit
generic.

The goal of this patch is to rename this struct to `io_issue_def`. This
struct will contain the hot functions associated with the issue code
path.

For now, this patch only renames the structure, and an upcoming patch
will break up the structure in two, moving the non-issue fields to a
secondary struct.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20230112144411.2624698-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Dmitrii Bundin
81594e7e7a io_uring: remove excessive unlikely on IS_ERR
The IS_ERR function uses the IS_ERR_VALUE macro under the hood which
already wraps the condition into unlikely.

Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
Link: https://lore.kernel.org/r/20230109185854.25698-1-dmitrii.bundin.a@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
544d163d65 io_uring: lock overflowing for IOPOLL
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 <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-13 07:32:46 -07:00
Jens Axboe
1e23db450c io_uring: use iter_ubuf for single range imports
This is more efficient than iter_iov.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
[merge to 6.2, minor fixes]
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-01-08 20:59:17 -07:00
Pavel Begunkov
a8cf95f936 io_uring: fix overflow handling regression
Because the single task locking series got reordered ahead of the
timeout and completion lock changes, two hunks inadvertently ended up
using __io_fill_cqe_req() rather than io_fill_cqe_req(). This meant
that we dropped overflow handling in those two spots. Reinstate the
correct CQE filling helper.

Fixes: f66f73421f ("io_uring: skip spinlocking for ->task_complete")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-15 08:20:10 -07:00