Commit Graph

451 Commits

Author SHA1 Message Date
Pavel Begunkov f4a1254f2a io_uring: fix cancellation overwriting req->flags
Only the current owner of a request is allowed to write into req->flags.
Hence, the cancellation path should never touch it. Add a new field
instead of the flag, move it into the 3rd cache line because it should
always be initialised. poll_refs can move further as polling is an
involved process anyway.

It's a minimal patch, in the future we can and should find a better
place for it and remove now unused REQ_F_CANCEL_SEQ.

Fixes: 521223d7c2 ("io_uring/cancel: don't default to setting req->work.cancel_seq")
Cc: stable@vger.kernel.org
Reported-by: Li Shi <sl1589472800@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6827b129f8f0ad76fa9d1f0a773de938b240ffab.1718323430.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-13 19:25:28 -06:00
Jens Axboe 547988ad0f io_uring: remove checks for NULL 'sq_offset'
Since the 5.12 kernel release, nobody has been passing NULL as the
sq_offset pointer. Remove the checks for it being NULL or not, it will
always be valid.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-22 11:13:44 -06:00
Linus Torvalds 9961a78594 for-6.10/io_uring-20240511
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Merge tag 'for-6.10/io_uring-20240511' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:

 - Greatly improve send zerocopy performance, by enabling coalescing of
   sent buffers.

   MSG_ZEROCOPY already does this with send(2) and sendmsg(2), but the
   io_uring side did not. In local testing, the crossover point for send
   zerocopy being faster is now around 3000 byte packets, and it
   performs better than the sync syscall variants as well.

   This feature relies on a shared branch with net-next, which was
   pulled into both branches.

 - Unification of how async preparation is done across opcodes.

   Previously, opcodes that required extra memory for async retry would
   allocate that as needed, using on-stack state until that was the
   case. If async retry was needed, the on-stack state was adjusted
   appropriately for a retry and then copied to the allocated memory.

   This led to some fragile and ugly code, particularly for read/write
   handling, and made storage retries more difficult than they needed to
   be. Allocate the memory upfront, as it's cheap from our pools, and
   use that state consistently both initially and also from the retry
   side.

 - Move away from using remap_pfn_range() for mapping the rings.

   This is really not the right interface to use and can cause lifetime
   issues or leaks. Additionally, it means the ring sq/cq arrays need to
   be physically contigious, which can cause problems in production with
   larger rings when services are restarted, as memory can be very
   fragmented at that point.

   Move to using vm_insert_page(s) for the ring sq/cq arrays, and apply
   the same treatment to mapped ring provided buffers. This also helps
   unify the code we have dealing with allocating and mapping memory.

   Hard to see in the diffstat as we're adding a few features as well,
   but this kills about ~400 lines of code from the codebase as well.

 - Add support for bundles for send/recv.

   When used with provided buffers, bundles support sending or receiving
   more than one buffer at the time, improving the efficiency by only
   needing to call into the networking stack once for multiple sends or
   receives.

 - Tweaks for our accept operations, supporting both a DONTWAIT flag for
   skipping poll arm and retry if we can, and a POLLFIRST flag that the
   application can use to skip the initial accept attempt and rely
   purely on poll for triggering the operation. Both of these have
   identical flags on the receive side already.

 - Make the task_work ctx locking unconditional.

   We had various code paths here that would do a mix of lock/trylock
   and set the task_work state to whether or not it was locked. All of
   that goes away, we lock it unconditionally and get rid of the state
   flag indicating whether it's locked or not.

   The state struct still exists as an empty type, can go away in the
   future.

 - Add support for specifying NOP completion values, allowing it to be
   used for error handling testing.

 - Use set/test bit for io-wq worker flags. Not strictly needed, but
   also doesn't hurt and helps silence a KCSAN warning.

 - Cleanups for io-wq locking and work assignments, closing a tiny race
   where cancelations would not be able to find the work item reliably.

 - Misc fixes, cleanups, and improvements

* tag 'for-6.10/io_uring-20240511' of git://git.kernel.dk/linux: (97 commits)
  io_uring: support to inject result for NOP
  io_uring: fail NOP if non-zero op flags is passed in
  io_uring/net: add IORING_ACCEPT_POLL_FIRST flag
  io_uring/net: add IORING_ACCEPT_DONTWAIT flag
  io_uring/filetable: don't unnecessarily clear/reset bitmap
  io_uring/io-wq: Use set_bit() and test_bit() at worker->flags
  io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ring
  io_uring: Require zeroed sqe->len on provided-buffers send
  io_uring/notif: disable LAZY_WAKE for linked notifs
  io_uring/net: fix sendzc lazy wake polling
  io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it
  io_uring/rw: reinstate thread check for retries
  io_uring/notif: implement notification stacking
  io_uring/notif: simplify io_notif_flush()
  net: add callback for setting a ubuf_info to skb
  net: extend ubuf_info callback to ops structure
  io_uring/net: support bundles for recv
  io_uring/net: support bundles for send
  io_uring/kbuf: add helpers for getting/peeking multiple buffers
  io_uring/net: add provided buffer support for IORING_OP_SEND
  ...
2024-05-13 12:48:06 -07:00
Linus Torvalds 1b0aabcc9a vfs-6.10.misc
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Merge tag 'vfs-6.10.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "This contains the usual miscellaneous features, cleanups, and fixes
  for vfs and individual fses.

  Features:

   - Free up FMODE_* bits. I've freed up bits 6, 7, 8, and 24. That
     means we now have six free FMODE_* bits in total (but bit #6
     already got used for FMODE_WRITE_RESTRICTED)

   - Add FOP_HUGE_PAGES flag (follow-up to FMODE_* cleanup)

   - Add fd_raw cleanup class so we can make use of automatic cleanup
     provided by CLASS(fd_raw, f)(fd) for O_PATH fds as well

   - Optimize seq_puts()

   - Simplify __seq_puts()

   - Add new anon_inode_getfile_fmode() api to allow specifying f_mode
     instead of open-coding it in multiple places

   - Annotate struct file_handle with __counted_by() and use
     struct_size()

   - Warn in get_file() whether f_count resurrection from zero is
     attempted (epoll/drm discussion)

   - Folio-sophize aio

   - Export the subvolume id in statx() for both btrfs and bcachefs

   - Relax linkat(AT_EMPTY_PATH) requirements

   - Add F_DUPFD_QUERY fcntl() allowing to compare two file descriptors
     for dup*() equality replacing kcmp()

  Cleanups:

   - Compile out swapfile inode checks when swap isn't enabled

   - Use (1 << n) notation for FMODE_* bitshifts for clarity

   - Remove redundant variable assignment in fs/direct-io

   - Cleanup uses of strncpy in orangefs

   - Speed up and cleanup writeback

   - Move fsparam_string_empty() helper into header since it's currently
     open-coded in multiple places

   - Add kernel-doc comments to proc_create_net_data_write()

   - Don't needlessly read dentry->d_flags twice

  Fixes:

   - Fix out-of-range warning in nilfs2

   - Fix ecryptfs overflow due to wrong encryption packet size
     calculation

   - Fix overly long line in xfs file_operations (follow-up to FMODE_*
     cleanup)

   - Don't raise FOP_BUFFER_{R,W}ASYNC for directories in xfs (follow-up
     to FMODE_* cleanup)

   - Don't call xfs_file_open from xfs_dir_open (follow-up to FMODE_*
     cleanup)

   - Fix stable offset api to prevent endless loops

   - Fix afs file server rotations

   - Prevent xattr node from overflowing the eraseblock in jffs2

   - Move fdinfo PTRACE_MODE_READ procfs check into the .permission()
     operation instead of .open() operation since this caused userspace
     regressions"

* tag 'vfs-6.10.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
  afs: Fix fileserver rotation getting stuck
  selftests: add F_DUPDFD_QUERY selftests
  fcntl: add F_DUPFD_QUERY fcntl()
  file: add fd_raw cleanup class
  fs: WARN when f_count resurrection is attempted
  seq_file: Simplify __seq_puts()
  seq_file: Optimize seq_puts()
  proc: Move fdinfo PTRACE_MODE_READ check into the inode .permission operation
  fs: Create anon_inode_getfile_fmode()
  xfs: don't call xfs_file_open from xfs_dir_open
  xfs: drop fop_flags for directories
  xfs: fix overly long line in the file_operations
  shmem: Fix shmem_rename2()
  libfs: Add simple_offset_rename() API
  libfs: Fix simple_offset_rename_exchange()
  jffs2: prevent xattr node from overflowing the eraseblock
  vfs, swap: compile out IS_SWAPFILE() on swapless configs
  vfs: relax linkat() AT_EMPTY_PATH - aka flink() - requirements
  fs/direct-io: remove redundant assignment to variable retval
  fs/dcache: Re-use value stored to dentry->d_flags instead of re-reading
  ...
2024-05-13 11:40:06 -07:00
Jens Axboe 039a2e800b io_uring/rw: reinstate thread check for retries
Allowing retries for everything is arguably the right thing to do, now
that every command type is async read from the start. But it's exposed a
few issues around missing check for a retry (which cca6571381 exposed),
and the fixup commit for that isn't necessarily 100% sound in terms of
iov_iter state.

For now, just revert these two commits. This unfortunately then re-opens
the fact that -EAGAIN can get bubbled to userspace for some cases where
the kernel very well could just sanely retry them. But until we have all
the conditions covered around that, we cannot safely enable that.

This reverts commit df604d2ad4.
This reverts commit cca6571381.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-25 09:04:32 -06:00
Jens Axboe 2f9c9515bd io_uring/net: support bundles for recv
If IORING_OP_RECV is used with provided buffers, the caller may also set
IORING_RECVSEND_BUNDLE to turn it into a multi-buffer recv. This grabs
buffers available and receives into them, posting a single completion for
all of it.

This can be used with multishot receive as well, or without it.

Now that both send and receive support bundles, add a feature flag for
it as well. If IORING_FEAT_RECVSEND_BUNDLE is set after registering the
ring, then the kernel supports bundles for recv and send.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-22 11:26:11 -06:00
Jens Axboe df604d2ad4 io_uring/rw: ensure retry condition isn't lost
A previous commit removed the checking on whether or not it was possible
to retry a request, since it's now possible to retry any of them. This
would previously have caused the request to have been ended with an error,
but now the retry condition can simply get lost instead.

Cleanup the retry handling and always just punt it to task_work, which
will queue it with io-wq appropriately.

Reported-by: Changhui Zhong <czhong@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Fixes: cca6571381 ("io_uring/rw: cleanup retry path")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 09:23:55 -06:00
Jens Axboe 686b56cbee io_uring: ensure overflow entries are dropped when ring is exiting
A previous consolidation cleanup missed handling the case where the ring
is dying, and __io_cqring_overflow_flush() doesn't flush entries if the
CQ ring is already full. This is fine for the normal CQE overflow
flushing, but if the ring is going away, we need to flush everything,
even if it means simply freeing the overflown entries.

Fixes: 6c948ec44b29 ("io_uring: consolidate overflow flushing")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:27 -06:00
Pavel Begunkov 6b231248e9 io_uring: consolidate overflow flushing
Consolidate __io_cqring_overflow_flush and io_cqring_overflow_kill()
into a single function as it once was, it's easier to work with it this
way.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/986b42c35e76a6be7aa0cdcda0a236a2222da3a7.1712708261.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:27 -06:00
Pavel Begunkov 8d09a88ef9 io_uring: always lock __io_cqring_overflow_flush
Conditional locking is never great, in case of
__io_cqring_overflow_flush(), which is a slow path, it's not justified.
Don't handle IOPOLL separately, always grab uring_lock for overflow
flushing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/162947df299aa12693ac4b305dacedab32ec7976.1712708261.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Pavel Begunkov 408024b959 io_uring: open code io_cqring_overflow_flush()
There is only one caller of io_cqring_overflow_flush(), open code it

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a1fecd56d9dba923ed8d4d159727fa939d3baa2a.1712708261.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Pavel Begunkov e45ec969d1 io_uring: remove extra SQPOLL overflow flush
c1edbf5f08 ("io_uring: flag SQPOLL busy condition to userspace")
added an extra overflowed CQE flush in the SQPOLL submission path due to
backpressure, which was later removed. Remove the flush and let
io_cqring_wait() / iopoll handle it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2a83b0724ca6ca9d16c7d79a51b77c81876b2e39.1712708261.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Pavel Begunkov a5bff51850 io_uring: unexport io_req_cqe_overflow()
There are no users of io_req_cqe_overflow() apart from io_uring.c, make
it static.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f4295eb2f9eb98d5db38c0578f57f0b86bfe0d8c.1712708261.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Ming Lei bbbef3e9d2 io_uring: return void from io_put_kbuf_comp()
The only caller doesn't handle the return value of io_put_kbuf_comp(), so
change its return type into void.

Also follow Jens's suggestion to rename it as io_put_kbuf_drop().

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240407132759.4056167-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Pavel Begunkov c29006a245 io_uring: remove io_req_put_rsrc_locked()
io_req_put_rsrc_locked() is a weird shim function around
io_req_put_rsrc(). All calls to io_req_put_rsrc() require holding
->uring_lock, so we can just use it directly.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a195bc78ac3d2c6fbaea72976e982fe51e50ecdd.1712331455.git.asml.silence@gmail.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Pavel Begunkov d9713ad3fa io_uring: remove async request cache
io_req_complete_post() was a sole user of ->locked_free_list, but
since we just gutted the function, the cache is not used anymore and
can be removed.

->locked_free_list served as an asynhronous counterpart of the main
request (i.e. struct io_kiocb) cache for all unlocked cases like io-wq.
Now they're all forced to be completed into the main cache directly,
off of the normal completion path or via io_free_req().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7bffccd213e370abd4de480e739d8b08ab6c1326.1712331455.git.asml.silence@gmail.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Pavel Begunkov de96e9ae69 io_uring: turn implicit assumptions into a warning
io_req_complete_post() is now io-wq only and shouldn't be used outside
of it, i.e. it relies that io-wq holds a ref for the request as
explained in a comment below. Let's add a warning to enforce the
assumption and make sure nobody would try to do anything weird.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1013b60c35d431d0698cafbc53c06f5917348c20.1712331455.git.asml.silence@gmail.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Ming Lei f39130004d io_uring: kill dead code in io_req_complete_post
Since commit 8f6c829491fe ("io_uring: remove struct io_tw_state::locked"),
io_req_complete_post() is only called from io-wq submit work, where the
request reference is guaranteed to be grabbed and won't drop to zero
in io_req_complete_post().

Kill the dead code, meantime add req_ref_put() to put the reference.

Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1d8297e2046553153e763a52574f0e0f4d512f86.1712331455.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Jens Axboe f15ed8b4d0 io_uring: move mapping/allocation helpers to a separate file
Move the related code from io_uring.c into memmap.c. No functional
changes in this patch, just cleaning it up a bit now that the full
transition is done.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Jens Axboe 18595c0a58 io_uring: use unpin_user_pages() where appropriate
There are a few cases of open-rolled loops around unpin_user_page(), use
the generic helper instead.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Jens Axboe 87585b0575 io_uring/kbuf: use vm_insert_pages() for mmap'ed pbuf ring
Rather than use remap_pfn_range() for this and manually free later,
switch to using vm_insert_page() and have it Just Work.

This requires a bit of effort on the mmap lookup side, as the ctx
uring_lock isn't held, which  otherwise protects buffer_lists from being
torn down, and it's not safe to grab from mmap context that would
introduce an ABBA deadlock between the mmap lock and the ctx uring_lock.
Instead, lookup the buffer_list under RCU, as the the list is RCU freed
already. Use the existing reference count to determine whether it's
possible to safely grab a reference to it (eg if it's not zero already),
and drop that reference when done with the mapping. If the mmap
reference is the last one, the buffer_list and the associated memory can
go away, since the vma insertion has references to the inserted pages at
that point.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Jens Axboe 1943f96b38 io_uring: unify io_pin_pages()
Move it into io_uring.c where it belongs, and use it in there as well
rather than have two implementations of this.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Jens Axboe 09fc75e0c0 io_uring: use vmap() for ring mapping
This is the last holdout which does odd page checking, convert it to
vmap just like what is done for the non-mmap path.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Jens Axboe 3ab1db3c60 io_uring: get rid of remap_pfn_range() for mapping rings/sqes
Rather than use remap_pfn_range() for this and manually free later,
switch to using vm_insert_pages() and have it Just Work.

If possible, allocate a single compound page that covers the range that
is needed. If that works, then we can just use page_address() on that
page. If we fail to get a compound page, allocate single pages and use
vmap() to map them into the kernel virtual address space.

This just covers the rings/sqes, the other remaining user of the mmap
remap_pfn_range() user will be converted separately. Once that is done,
we can kill the old alloc/free code.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Joel Granados a80929d1cd io_uring: Remove the now superfluous sentinel elements from ctl_table array
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which will
reduce the overall build time size of the kernel and run time memory
bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove sentinel element from kernel_io_uring_disabled_table

Signed-off-by: Joel Granados <j.granados@samsung.com>
Link: https://lore.kernel.org/r/20240328-jag-sysctl_remset_misc-v1-6-47c1463b3af2@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:26 -06:00
Jiapeng Chong 4e9706c6c8 io_uring: Remove unused function
The function are defined in the io_uring.c file, but not called
elsewhere, so delete the unused function.

io_uring/io_uring.c:646:20: warning: unused function '__io_cq_unlock'.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=8660
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240328022324.78029-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:25 -06:00
Jens Axboe 05eb5fe226 io_uring: refill request cache in memory order
The allocator will generally return memory in order, but
__io_alloc_req_refill() then adds them to a stack and we'll extract them
in the opposite order. This obviously isn't a huge deal, but:

1) it makes debugging easier when they are in order
2) keeping them in-order is the right thing to do
3) reduces the code for adding them to the stack

Just add them in reverse to the stack.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:25 -06:00
Jens Axboe da22bdf38b io_uring/poll: shrink alloc cache size to 32
This should be plenty, rather than the default of 128, and matches what
we have on the rsrc and futex side as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:25 -06:00
Jens Axboe 414d0f45c3 io_uring/alloc_cache: switch to array based caching
Currently lists are being used to manage this, but best practice is
usually to have these in an array instead as that it cheaper to manage.

Outside of that detail, games are also played with KASAN as the list
is inside the cached entry itself.

Finally, all users of this need a struct io_cache_entry embedded in
their struct, which is union'ized with something else in there that
isn't used across the free -> realloc cycle.

Get rid of all of that, and simply have it be an array. This will not
change the memory used, as we're just trading an 8-byte member entry
for the per-elem array size.

This reduces the overhead of the recycled allocations, and it reduces
the amount of code code needed to support recycling to about half of
what it currently is.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:25 -06:00
Jens Axboe e10677a8f6 io_uring: drop ->prep_async()
It's now unused, drop the code related to it. This includes the
io_issue_defs->manual alloc field.

While in there, and since ->async_size is now being used a bit more
frequently and in the issue path, move it to io_issue_defs[].

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:25 -06:00
Jens Axboe d10f19dff5 io_uring/uring_cmd: switch to always allocating async data
Basic conversion ensuring async_data is allocated off the prep path. Adds
a basic alloc cache as well, as passthrough IO can be quite high in rate.

Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:25 -06:00
Jens Axboe a9165b83c1 io_uring/rw: always setup io_async_rw for read/write requests
read/write requests try to put everything on the stack, and then alloc
and copy if a retry is needed. This necessitates a bunch of nasty code
that deals with intermediate state.

Get rid of this, and have the prep side setup everything that is needed
upfront, which greatly simplifies the opcode handlers.

This includes adding an alloc cache for io_async_rw, to make it cheap
to handle.

In terms of cost, this should be basically free and transparent. For
the worst case of {READ,WRITE}_FIXED which didn't need it before,
performance is unaffected in the normal peak workload that is being
used to test that. Still runs at 122M IOPS.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:25 -06:00
Jens Axboe 29f858a7c6 io_uring: remove timeout/poll specific cancelations
For historical reasons these were special cased, as they were the only
ones that needed cancelation. But now we handle cancelations generally,
and hence there's no need to check for these in
io_ring_ctx_wait_and_kill() when io_uring_try_cancel_requests() handles
both these and the rest as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:25 -06:00
Jens Axboe 2541762342 io_uring: flush delayed fallback task_work in cancelation
Just like we run the inline task_work, ensure we also factor in and
run the fallback task_work.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
Pavel Begunkov 0667db14e1 io_uring: refactor io_req_complete_post()
Make io_req_complete_post() to push all IORING_SETUP_IOPOLL requests
to task_work, it's much cleaner and should normally happen. We couldn't
do it before because there was a possibility of looping in

complete_post() -> tw -> complete_post() -> ...

Also, unexport the function and inline __io_req_complete_post().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/ea19c032ace3e0dd96ac4d991a063b0188037014.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
Pavel Begunkov 23fbdde620 io_uring: remove current check from complete_post
task_work execution is now always locked, and we shouldn't get into
io_req_complete_post() from them. That means that complete_post() is
always called out of the original task context and we don't even need to
check current.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/24ec27f27db0d8f58c974d8118dca1d345314ddc.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
Pavel Begunkov 902ce82c2a io_uring: get rid of intermediate aux cqe caches
io_post_aux_cqe(), which is used for multishot requests, delays
completions by putting CQEs into a temporary array for the purpose
completion lock/flush batching.

DEFER_TASKRUN doesn't need any locking, so for it we can put completions
directly into the CQ and defer post completion handling with a flag.
That leaves !DEFER_TASKRUN, which is not that interesting / hot for
multishot requests, so have conditional locking with deferred flush
for them.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/b1d05a81fd27aaa2a07f9860af13059e7ad7a890.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
Pavel Begunkov e5c12945be io_uring: refactor io_fill_cqe_req_aux
The restriction on multishot execution context disallowing io-wq is
driven by rules of io_fill_cqe_req_aux(), it should only be called in
the master task context, either from the syscall path or in task_work.
Since task_work now always takes the ctx lock implying
IO_URING_F_COMPLETE_DEFER, we can just assume that the function is
always called with its defer argument set to true.

Kill the argument. Also rename the function for more consistency as
"fill" in CQE related functions was usually meant for raw interfaces
only copying data into the CQ without any locking, waking the user
and other accounting "post" functions take care of.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/93423d106c33116c7d06bf277f651aa68b427328.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
Pavel Begunkov 8e5b3b89ec io_uring: remove struct io_tw_state::locked
ctx is always locked for task_work now, so get rid of struct
io_tw_state::locked. Note I'm stopping one step before removing
io_tw_state altogether, which is not empty, because it still serves the
purpose of indicating which function is a tw callback and forcing users
not to invoke them carelessly out of a wrong context. The removal can
always be done later.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/e95e1ea116d0bfa54b656076e6a977bc221392a4.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
Pavel Begunkov 92219afb98 io_uring: force tw ctx locking
We can run normal task_work without locking the ctx, however we try to
lock anyway and most handlers prefer or require it locked. It might have
been interesting to multi-submitter ring with high contention completing
async read/write requests via task_work, however that will still need to
go through io_req_complete_post() and potentially take the lock for
rsrc node putting or some other case.

In other words, it's hard to care about it, so alawys force the locking.
The case described would also because of various io_uring caches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/6ae858f2ef562e6ed9f13c60978c0d48926954ba.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
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
Pavel Begunkov da12d9ab58 io_uring/cmd: move io_uring_try_cancel_uring_cmd()
io_uring_try_cancel_uring_cmd() is a part of the cmd handling so let's
move it closer to all cmd bits into uring_cmd.c

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/43a3937af4933655f0fd9362c381802f804f43de.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-15 08:10:24 -06:00
Christian Brauner 210a03c9d5
fs: claw back a few FMODE_* bits
There's a bunch of flags that are purely based on what the file
operations support while also never being conditionally set or unset.
IOW, they're not subject to change for individual files. Imho, such
flags don't need to live in f_mode they might as well live in the fops
structs itself. And the fops struct already has that lonely
mmap_supported_flags member. We might as well turn that into a generic
fop_flags member and move a few flags from FMODE_* space into FOP_*
space. That gets us four FMODE_* bits back and the ability for new
static flags that are about file ops to not have to live in FMODE_*
space but in their own FOP_* space. It's not the most beautiful thing
ever but it gets the job done. Yes, there'll be an additional pointer
chase but hopefully that won't matter for these flags.

I suspect there's a few more we can move into there and that we can also
redirect a bunch of new flag suggestions that follow this pattern into
the fop_flags field instead of f_mode.

Link: https://lore.kernel.org/r/20240328-gewendet-spargel-aa60a030ef74@brauner
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-04-07 13:49:02 +02:00
Alexey Izbyshev 978e5c19df io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure
This bug was introduced in commit 950e79dd73 ("io_uring: minor
io_cqring_wait() optimization"), which was made in preparation for
adc8682ec6 ("io_uring: Add support for napi_busy_poll"). The latter
got reverted in cb31821673 ("Revert "io_uring: Add support for
napi_busy_poll""), so simply undo the former as well.

Cc: stable@vger.kernel.org
Fixes: 950e79dd73 ("io_uring: minor io_cqring_wait() optimization")
Signed-off-by: Alexey Izbyshev <izbyshev@ispras.ru>
Link: https://lore.kernel.org/r/20240405125551.237142-1-izbyshev@ispras.ru
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-05 20:05:41 -06:00
Jens Axboe 561e4f9451 io_uring/kbuf: hold io_buffer_list reference over mmap
If we look up the kbuf, ensure that it doesn't get unregistered until
after we're done with it. Since we're inside mmap, we cannot safely use
the io_uring lock. Rely on the fact that we can lookup the buffer list
under RCU now and grab a reference to it, preventing it from being
unregistered until we're done with it. The lookup returns the
io_buffer_list directly with it referenced.

Cc: stable@vger.kernel.org # v6.4+
Fixes: 5cf4f52e6d ("io_uring: free io_buffer_list entries via RCU")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-02 19:03:27 -06:00
Jens Axboe 09ab7eff38 io_uring/kbuf: get rid of lower BGID lists
Just rely on the xarray for any kind of bgid. This simplifies things, and
it really doesn't bring us much, if anything.

Cc: stable@vger.kernel.org # v6.4+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-02 19:03:13 -06:00
Jens Axboe 73eaa2b583 io_uring: use private workqueue for exit work
Rather than use the system unbound event workqueue, use an io_uring
specific one. This avoids dependencies with the tty, which also uses
the system_unbound_wq, and issues flushes of said workqueue from inside
its poll handling.

Cc: stable@vger.kernel.org
Reported-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>
Tested-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>
Tested-by: Iskren Chernev <me@iskren.info>
Link: https://github.com/axboe/liburing/issues/1113
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-02 07:35:16 -06:00
Jens Axboe bee1d5becd io_uring: disable io-wq execution of multishot NOWAIT requests
Do the same check for direct io-wq execution for multishot requests that
commit 2a975d426c did for the inline execution, and disable multishot
mode (and revert to single shot) if the file type doesn't support NOWAIT,
and isn't opened in O_NONBLOCK mode. For multishot to work properly, it's
a requirement that nonblocking read attempts can be done.

Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-01 11:46:22 -06:00
Jens Axboe e21e1c45e1 io_uring: clear opcode specific data for an early failure
If failure happens before the opcode prep handler is called, ensure that
we clear the opcode specific area of the request, which holds data
specific to that request type. This prevents errors where opcode
handlers either don't get to clear per-request private data since prep
isn't even called.

Reported-and-tested-by: syzbot+f8e9a371388aa62ecab4@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-16 11:24:50 -06:00
Gabriel Krisman Bertazi 67d1189d10 io_uring: Fix release of pinned pages when __io_uaddr_map fails
Looking at the error path of __io_uaddr_map, if we fail after pinning
the pages for any reasons, ret will be set to -EINVAL and the error
handler won't properly release the pinned pages.

I didn't manage to trigger it without forcing a failure, but it can
happen in real life when memory is heavily fragmented.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Fixes: 223ef47431 ("io_uring: don't allow IORING_SETUP_NO_MMAP rings on highmem pages")
Link: https://lore.kernel.org/r/20240313213912.1920-1-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-13 16:08:25 -06:00