Commit Graph

1743 Commits

Author SHA1 Message Date
Alok Tiwari
c4d145b336 io_uring: correct __must_hold annotation in io_install_fixed_file
[ Upstream commit c5efc6a0b3940381d67887302ddb87a5cf623685 ]

The __must_hold annotation references &req->ctx->uring_lock, but req
is not in scope in io_install_fixed_file. This change updates the
annotation to reference the correct ctx->uring_lock.
improving code clarity.

Fixes: f110ed8498 ("io_uring: split out fixed file installation and removal")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-29 14:10:28 +01:00
Alok Tiwari
0dc956645e io_uring: fix incorrect unlikely() usage in io_waitid_prep()
[ Upstream commit 4ec703ec0c384a2199808c4eb2e9037236285a8d ]

The negation operator is incorrectly placed outside the unlikely()
macro:

    if (!unlikely(iwa))

This inverts the compiler branch prediction hint, marking the NULL case
as likely instead of unlikely. The intent is to indicate that allocation
failures are rare, consistent with common kernel patterns.

 Moving the negation inside unlikely():

    if (unlikely(!iwa))

Fixes: 2b4fc4cd43 ("io_uring/waitid: setup async data in the prep handler")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-29 14:10:28 +01:00
Jens Axboe
7d95de1244 io_uring/sqpoll: be smarter on when to update the stime usage
commit a94e0657269c5b8e1a90b17aa2c048b3d276e16d upstream.

The current approach is a bit naive, and hence calls the time querying
way too often. Only start the "doing work" timer when there's actual
work to do, and then use that information to terminate (and account) the
work time once done. This greatly reduces the frequency of these calls,
when they cannot have changed anyway.

Running a basic random reader that is setup to use SQPOLL, a profile
before this change shows these as the top cycle consumers:

+   32.60%  iou-sqp-1074  [kernel.kallsyms]  [k] thread_group_cputime_adjusted
+   19.97%  iou-sqp-1074  [kernel.kallsyms]  [k] thread_group_cputime
+   12.20%  io_uring      io_uring           [.] submitter_uring_fn
+    4.13%  iou-sqp-1074  [kernel.kallsyms]  [k] getrusage
+    2.45%  iou-sqp-1074  [kernel.kallsyms]  [k] io_submit_sqes
+    2.18%  iou-sqp-1074  [kernel.kallsyms]  [k] __pi_memset_generic
+    2.09%  iou-sqp-1074  [kernel.kallsyms]  [k] cputime_adjust

and after this change, top of profile looks as follows:

+   36.23%  io_uring     io_uring           [.] submitter_uring_fn
+   23.26%  iou-sqp-819  [kernel.kallsyms]  [k] io_sq_thread
+   10.14%  iou-sqp-819  [kernel.kallsyms]  [k] io_sq_tw
+    6.52%  iou-sqp-819  [kernel.kallsyms]  [k] tctx_task_work_run
+    4.82%  iou-sqp-819  [kernel.kallsyms]  [k] nvme_submit_cmds.part.0
+    2.91%  iou-sqp-819  [kernel.kallsyms]  [k] io_submit_sqes
[...]
     0.02%  iou-sqp-819  [kernel.kallsyms]  [k] cputime_adjust

where it's spending the cycles on things that actually matter.

Reported-by: Fengnan Chang <changfengnan@bytedance.com>
Cc: stable@vger.kernel.org
Fixes: 3fcb9d1720 ("io_uring/sqpoll: statistics of the true utilization of sq threads")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-29 14:10:21 +01:00
Jens Axboe
09e5505894 io_uring/sqpoll: switch away from getrusage() for CPU accounting
commit 8ac9b0d33e5c0a995338ee5f25fe1b6ff7d97f65 upstream.

getrusage() does a lot more than what the SQPOLL accounting needs, the
latter only cares about (and uses) the stime. Rather than do a full
RUSAGE_SELF summation, just query the used stime instead.

Cc: stable@vger.kernel.org
Fixes: 3fcb9d1720 ("io_uring/sqpoll: statistics of the true utilization of sq threads")
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-29 14:10:21 +01:00
Pavel Begunkov
79dd6f032e io_uring: protect mem region deregistration
commit be7cab44ed099566c605a8dac686c3254db01b35 upstream.

io_create_region_mmap_safe() protects publishing of a region against
concurrent mmap calls, however we should also protect against it when
removing a region. There is a gap io_register_mem_region() where it
safely publishes a region, but then copy_to_user goes wrong and it
unsafely frees the region.

Cc: stable@vger.kernel.org
Fixes: 087f997870 ("io_uring/memmap: implement mmap for regions")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23 16:24:22 +02:00
Jens Axboe
a11c61fa0b Revert "io_uring/rw: drop -EOPNOTSUPP check in __io_complete_rw_common()"
commit 927069c4ac2cd1a37efa468596fb5b8f86db9df0 upstream.

This reverts commit 90bfb28d5f.

Kevin reports that this commit causes an issue for him with LVM
snapshots, most likely because of turning off NOWAIT support while a
snapshot is being created. This makes -EOPNOTSUPP bubble back through
the completion handler, where io_uring read/write handling should just
retry it.

Reinstate the previous check removed by the referenced commit.

Cc: stable@vger.kernel.org
Fixes: 90bfb28d5f ("io_uring/rw: drop -EOPNOTSUPP check in __io_complete_rw_common()")
Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Reported-by: Kevin Lumik <kevin@xf.ee>
Link: https://lore.kernel.org/io-uring/cceb723c-051b-4de2-9a4c-4aa82e1619ee@kernel.dk/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23 16:24:21 +02:00
Pavel Begunkov
cf2b35668b io_uring/zcrx: increment fallback loop src offset
[ Upstream commit e9a9dcb4ccb32446165800a9d83058e95c4833d2 ]

Don't forget to adjust the source offset in io_copy_page(), otherwise
it'll be copying into the same location in some cases for highmem
setups.

Fixes: e67645bb7f ("io_uring/zcrx: prepare fallback for larger pages")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19 16:37:14 +02:00
Pavel Begunkov
8bcc9eaf1b io_uring/zcrx: fix overshooting recv limit
commit 09cfd3c52ea76f43b3cb15e570aeddf633d65e80 upstream.

It's reported that sometimes a zcrx request can receive more than was
requested. It's caused by io_zcrx_recv_skb() adjusting desc->count for
all received buffers including frag lists, but then doing recursive
calls to process frag list skbs, which leads to desc->count double
accounting and underflow.

Reported-and-tested-by: Matthias Jasny <matthiasjasny@gmail.com>
Fixes: 6699ec9a23 ("io_uring/zcrx: add a read limit to recvzc requests")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-15 12:04:15 +02:00
Jens Axboe
3e2205db2f io_uring/waitid: always prune wait queue entry in io_waitid_wait()
commit 2f8229d53d984c6a05b71ac9e9583d4354e3b91f upstream.

For a successful return, always remove our entry from the wait queue
entry list. Previously this was skipped if a cancelation was in
progress, but this can race with another invocation of the wait queue
entry callback.

Cc: stable@vger.kernel.org
Fixes: f31ecf671d ("io_uring: add IORING_OP_WAITID support")
Reported-by: syzbot+b9e83021d9c642a33d8c@syzkaller.appspotmail.com
Tested-by: syzbot+b9e83021d9c642a33d8c@syzkaller.appspotmail.com
Link: https://lore.kernel.org/io-uring/68e5195e.050a0220.256323.001f.GAE@google.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-15 12:04:15 +02:00
Linus Torvalds
0d64ebf676 Merge tag 'io_uring-6.17-20250919' of git://git.kernel.dk/linux
Pull io_uring fixes from Jens Axboe:

 - Fix for a regression introduced in the io-wq worker creation logic.

 - Remove the allocation cache for the msg_ring io_kiocb allocations. I
   have a suspicion that there's a bug there, and since we just fixed
   one in that area, let's just yank the use of that cache entirely.
   It's not that important, and it kills some code.

 - Treat a closed ring like task exiting in that any requests that
   trigger post that condition should just get canceled. Doesn't fix any
   real issues, outside of having tasks being able to rely on that
   guarantee.

 - Fix for a bug in the network zero-copy notification mechanism, where
   a comparison for matching tctx/ctx for notifications was buggy in
   that it didn't correctly compare with the previous notification.

* tag 'io_uring-6.17-20250919' of git://git.kernel.dk/linux:
  io_uring: fix incorrect io_kiocb reference in io_link_skb
  io_uring/msg_ring: kill alloc_cache for io_kiocb allocations
  io_uring: include dying ring in task_work "should cancel" state
  io_uring/io-wq: fix `max_workers` breakage and `nr_workers` underflow
2025-09-19 12:10:49 -07:00
Yang Xiuwei
2c139a47ef io_uring: fix incorrect io_kiocb reference in io_link_skb
In io_link_skb function, there is a bug where prev_notif is incorrectly
assigned using 'nd' instead of 'prev_nd'. This causes the context
validation check to compare the current notification with itself instead
of comparing it with the previous notification.

Fix by using the correct prev_nd parameter when obtaining prev_notif.

Signed-off-by: Yang Xiuwei <yangxiuwei@kylinos.cn>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Fixes: 6fe4220912 ("io_uring/notif: implement notification stacking")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-19 06:00:57 -06:00
Jens Axboe
df8922afc3 io_uring/msg_ring: kill alloc_cache for io_kiocb allocations
A recent commit:

fc582cd26e ("io_uring/msg_ring: ensure io_kiocb freeing is deferred for RCU")

fixed an issue with not deferring freeing of io_kiocb structs that
msg_ring allocates to after the current RCU grace period. But this only
covers requests that don't end up in the allocation cache. If a request
goes into the alloc cache, it can get reused before it is sane to do so.
A recent syzbot report would seem to indicate that there's something
there, however it may very well just be because of the KASAN poisoning
that the alloc_cache handles manually.

Rather than attempt to make the alloc_cache sane for that use case, just
drop the usage of the alloc_cache for msg_ring request payload data.

Fixes: 50cf5f3842 ("io_uring/msg_ring: add an alloc cache for io_kiocb entries")
Link: https://lore.kernel.org/io-uring/68cc2687.050a0220.139b6.0005.GAE@google.com/
Reported-by: syzbot+baa2e0f4e02df602583e@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-18 13:59:15 -06:00
Jens Axboe
3539b1467e io_uring: include dying ring in task_work "should cancel" state
When running task_work for an exiting task, rather than perform the
issue retry attempt, the task_work is canceled. However, this isn't
done for a ring that has been closed. This can lead to requests being
successfully completed post the ring being closed, which is somewhat
confusing and surprising to an application.

Rather than just check the task exit state, also include the ring
ref state in deciding whether or not to terminate a given request when
run from task_work.

Cc: stable@vger.kernel.org # 6.1+
Link: https://github.com/axboe/liburing/discussions/1459
Reported-by: Benedek Thaler <thaler@thaler.hu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-18 10:24:50 -06:00
Max Kellermann
cd4ea81be3 io_uring/io-wq: fix max_workers breakage and nr_workers underflow
Commit 88e6c42e40de ("io_uring/io-wq: add check free worker before
create new worker") reused the variable `do_create` for something
else, abusing it for the free worker check.

This caused the value to effectively always be `true` at the time
`nr_workers < max_workers` was checked, but it should really be
`false`.  This means the `max_workers` setting was ignored, and worse:
if the limit had already been reached, incrementing `nr_workers` was
skipped even though another worker would be created.

When later lots of workers exit, the `nr_workers` field could easily
underflow, making the problem worse because more and more workers
would be created without incrementing `nr_workers`.

The simple solution is to use a different variable for the free worker
check instead of using one variable for two different things.

Cc: stable@vger.kernel.org
Fixes: 88e6c42e40de ("io_uring/io-wq: add check free worker before create new worker")
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-15 10:46:13 -06:00
Linus Torvalds
f777d1112e Merge tag 'vfs-6.17-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
 "fuse:

   - Prevent opening of non-regular backing files.

     Fuse doesn't support non-regular files anyway.

   - Check whether copy_file_range() returns a larger size than
     requested.

   - Prevent overflow in copy_file_range() as fuse currently only
     supports 32-bit sized copies.

   - Cache the blocksize value if the server returned a new value as
     inode->i_blkbits isn't modified directly anymore.

   - Fix i_blkbits handling for iomap partial writes.

     By default i_blkbits is set to PAGE_SIZE which causes iomap to mark
     the whole folio as uptodate even on a partial write. But fuseblk
     filesystems support choosing a blocksize smaller than PAGE_SIZE
     risking data corruption. Simply enforce PAGE_SIZE as blocksize for
     fuseblk's internal inode for now.

   - Prevent out-of-bounds acces in fuse_dev_write() when the number of
     bytes to be retrieved is truncated to the fc->max_pages limit.

  virtiofs:

   - Fix page faults for DAX page addresses.

  Misc:

   - Tighten file handle decoding from userns.

     Check that the decoded dentry itself has a valid idmapping in the
     user namespace.

   - Fix mount-notify selftests.

   - Fix some indentation errors.

   - Add an FMODE_ flag to indicate IOCB_HAS_METADATA availability.

     This will be moved to an FOP_* flag with a bit more rework needed
     for that to happen not suitable for a fix.

   - Don't silently ignore metadata for sync read/write.

   - Don't pointlessly log warning when reading coredump sysctls"

* tag 'vfs-6.17-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fuse: virtio_fs: fix page fault for DAX page address
  selftests/fs/mount-notify: Fix compilation failure.
  fhandle: use more consistent rules for decoding file handle from userns
  fuse: Block access to folio overlimit
  fuse: fix fuseblk i_blkbits for iomap partial writes
  fuse: reflect cached blocksize if blocksize was changed
  fuse: prevent overflow in copy_file_range return value
  fuse: check if copy_file_range() returns larger than requested size
  fuse: do not allow mapping a non-regular backing file
  coredump: don't pointlessly check and spew warnings
  fs: fix indentation style
  block: don't silently ignore metadata for sync read/write
  fs: add a FMODE_ flag to indicate IOCB_HAS_METADATA availability
  Please enter a commit message to explain why this merge is necessary,
  especially if it merges an updated upstream into a topic branch.
2025-09-08 07:53:01 -07:00
Christian Brauner
e23654f5b1 Merge tag 'fuse-fixes-6.17-rc5' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse into vfs.fixes
fuse fixes for 6.17-rc5

* tag 'fuse-fixes-6.17-rc5' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (6 commits)
  fuse: Block access to folio overlimit
  fuse: fix fuseblk i_blkbits for iomap partial writes
  fuse: reflect cached blocksize if blocksize was changed
  fuse: prevent overflow in copy_file_range return value
  fuse: check if copy_file_range() returns larger than requested size
  fuse: do not allow mapping a non-regular backing file

Link: https://lore.kernel.org/CAJfpeguEVMMyw_zCb+hbOuSxdE2Z3Raw=SJsq=Y56Ae6dn2W3g@mail.gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-01 12:48:28 +02:00
Jens Axboe
98b6fa62c8 io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths
Since the buffers are mapped from userspace, it is prudent to use
READ_ONCE() to read the value into a local variable, and use that for
any other actions taken. Having a stable read of the buffer length
avoids worrying about it changing after checking, or being read multiple
times.

Similarly, the buffer may well change in between it being picked and
being committed. Ensure the looping for incremental ring buffer commit
stops if it hits a zero sized buffer, as no further progress can be made
at that point.

Fixes: ae98dbf43d ("io_uring/kbuf: add support for incremental buffer consumption")
Link: https://lore.kernel.org/io-uring/tencent_000C02641F6250C856D0C26228DE29A3D30A@qq.com/
Reported-by: Qingyue Zhang <chunzhennn@qq.com>
Reported-by: Suoxing Zhang <aftern00n@qq.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-28 05:48:34 -06:00
Qingyue Zhang
c64eff368a io_uring/kbuf: fix signedness in this_len calculation
When importing and using buffers, buf->len is considered unsigned.
However, buf->len is converted to signed int when committing. This can
lead to unexpected behavior if the buffer is large enough to be
interpreted as a negative value. Make min_t calculation unsigned.

Fixes: ae98dbf43d ("io_uring/kbuf: add support for incremental buffer consumption")
Co-developed-by: Suoxing Zhang <aftern00n@qq.com>
Signed-off-by: Suoxing Zhang <aftern00n@qq.com>
Signed-off-by: Qingyue Zhang <chunzhennn@qq.com>
Link: https://lore.kernel.org/r/tencent_4DBB3674C0419BEC2C0C525949DA410CA307@qq.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-27 08:39:44 -06:00
Jens Axboe
e4e6aaea46 io_uring: clear ->async_data as part of normal init
Opcode handlers like POLL_ADD will use ->async_data as the pointer for
double poll handling, which is a bit different than the usual case
where it's strictly gated by the REQ_F_ASYNC_DATA flag. Be a bit more
proactive in handling ->async_data, and clear it to NULL as part of
regular init. Init is touching that cacheline anyway, so might as well
clear it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-21 13:54:01 -06:00
Jens Axboe
508c1314b3 io_uring/futex: ensure io_futex_wait() cleans up properly on failure
The io_futex_data is allocated upfront and assigned to the io_kiocb
async_data field, but the request isn't marked with REQ_F_ASYNC_DATA
at that point. Those two should always go together, as the flag tells
io_uring whether the field is valid or not.

Additionally, on failure cleanup, the futex handler frees the data but
does not clear ->async_data. Clear the data and the flag in the error
path as well.

Thanks to Trend Micro Zero Day Initiative and particularly ReDress for
reporting this.

Cc: stable@vger.kernel.org
Fixes: 194bb58c60 ("io_uring: add support for futex wake and wait")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-21 13:53:33 -06:00
Christoph Hellwig
d072148a86 fs: add a FMODE_ flag to indicate IOCB_HAS_METADATA availability
Currently the kernel will happily route io_uring requests with metadata
to file operations that don't support it.  Add a FMODE_ flag to guard
that.

Fixes: 4de2ce04c8 ("fs: introduce IOCB_HAS_METADATA for metadata")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/20250819082517.2038819-2-hch@lst.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-08-20 11:12:58 +02:00
Fengnan Chang
9d83e1f05c io_uring/io-wq: add check free worker before create new worker
After commit 0b2b066f8a ("io_uring/io-wq: only create a new worker
if it can make progress"), in our produce environment, we still
observe that part of io_worker threads keeps creating and destroying.
After analysis, it was confirmed that this was due to a more complex
scenario involving a large number of fsync operations, which can be
abstracted as frequent write + fsync operations on multiple files in
a single uring instance. Since write is a hash operation while fsync
is not, and fsync is likely to be suspended during execution, the
action of checking the hash value in
io_wqe_dec_running cannot handle such scenarios.
Similarly, if hash-based work and non-hash-based work are sent at the
same time, similar issues are likely to occur.
Returning to the starting point of the issue, when a new work
arrives, io_wq_enqueue may wake up free worker A, while
io_wq_dec_running may create worker B. Ultimately, only one of A and
B can obtain and process the task, leaving the other in an idle
state. In the end, the issue is caused by inconsistent logic in the
checks performed by io_wq_enqueue and io_wq_dec_running.
Therefore, the problem can be resolved by checking for available
workers in io_wq_dec_running.

Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Reviewed-by: Diangang Li <lidiangang@bytedance.com>
Link: https://lore.kernel.org/r/20250813120214.18729-1-changfengnan@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-13 06:31:10 -06:00
Jens Axboe
41b70df5b3 io_uring/net: commit partial buffers on retry
Ring provided buffers are potentially only valid within the single
execution context in which they were acquired. io_uring deals with this
and invalidates them on retry. But on the networking side, if
MSG_WAITALL is set, or if the socket is of the streaming type and too
little was processed, then it will hang on to the buffer rather than
recycle or commit it. This is problematic for two reasons:

1) If someone unregisters the provided buffer ring before a later retry,
   then the req->buf_list will no longer be valid.

2) If multiple sockers are using the same buffer group, then multiple
   receives can consume the same memory. This can cause data corruption
   in the application, as either receive could land in the same
   userspace buffer.

Fix this by disallowing partial retries from pinning a provided buffer
across multiple executions, if ring provided buffers are used.

Cc: stable@vger.kernel.org
Reported-by: pt x <superman.xpt@gmail.com>
Fixes: c56e022c0a ("io_uring: add support for user mapped provided buffer ring")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-12 13:41:26 -06:00
Jens Axboe
33503c083f io_uring/memmap: cast nr_pages to size_t before shifting
If the allocated size exceeds UINT_MAX, then it's necessary to cast
the mr->nr_pages value to size_t to prevent it from overflowing. In
practice this isn't much of a concern as the required memory size will
have been validated upfront, and accounted to the user. And > 4GB sizes
will be necessary to make the lack of a cast a problem, which greatly
exceeds normal user locked_vm settings that are generally in the kb to
mb range. However, if root is used, then accounting isn't done, and
then it's possible to hit this issue.

Link: https://lore.kernel.org/all/6895b298.050a0220.7f033.0059.GAE@google.com/
Cc: stable@vger.kernel.org
Reported-by: syzbot+23727438116feb13df15@syzkaller.appspotmail.com
Fixes: 087f997870 ("io_uring/memmap: implement mmap for regions")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-08 06:35:14 -06:00
Norman Maurer
6f02527729 io_uring/net: Allow to do vectorized send
At the moment you have to use sendmsg for vectorized send.
While this works it's suboptimal as it also means you need to
allocate a struct msghdr that needs to be kept alive until a
submission happens. We can remove this limitation by just
allowing to use send directly.

Signed-off-by: Norman Maurer <norman_maurer@apple.com>
Link: https://lore.kernel.org/r/20250729065952.26646-1-norman_maurer@apple.com
[axboe: remove -EINVAL return for SENDMSG and SEND_VECTORIZED]
[axboe: allow send_zc to set SEND_VECTORIZED too]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-30 08:23:04 -06:00
Linus Torvalds
c3018a2c6a Merge tag 'for-6.17/io_uring-20250728' of git://git.kernel.dk/linux
Pull io_uring updates from Jens Axboe:

 - Optimization to avoid reference counts on non-cloned registered
   buffers. This is how these buffers were handled prior to having
   cloning support, and we can still use that approach as long as the
   buffers haven't been cloned to another ring.

 - Cleanup and improvement for uring_cmd, where btrfs was the only user
   of storing allocated data for the lifetime of the uring_cmd. Clean
   that up so we can get rid of the need to do that.

 - Avoid unnecessary memory copies in uring_cmd usage. This is
   particularly important as a lot of uring_cmd usage necessitates the
   use of 128b SQEs.

 - A few updates for recv multishot, where it's now possible to add
   fairness limits for limiting how much is transferred for each retry
   loop. Additionally, recv multishot now supports an overall cap as
   well, where once reached the multishot recv will terminate. The
   latter is useful for buffer management and juggling many recv streams
   at the same time.

 - Add support for returning the TX timestamps via a new socket command.
   This feature can work in either singleshot or multishot mode, where
   the latter triggers a completion whenever new timestamps are
   available. This is an alternative to using the existing error queue.

 - Add support for an io_uring "mock" file, which is the start of being
   able to do 100% targeted testing in terms of exercising io_uring
   request handling. The idea is to have a file type that can be
   anything the tester would like, and behave exactly how you want it to
   behave in terms of hitting the code paths you want.

 - Improve zcrx by using sgtables to de-duplicate and improve dma
   address handling.

 - Prep work for supporting larger pages for zcrx.

 - Various little improvements and fixes.

* tag 'for-6.17/io_uring-20250728' of git://git.kernel.dk/linux: (42 commits)
  io_uring/zcrx: fix leaking pages on sg init fail
  io_uring/zcrx: don't leak pages on account failure
  io_uring/zcrx: fix null ifq on area destruction
  io_uring: fix breakage in EXPERT menu
  io_uring/cmd: remove struct io_uring_cmd_data
  btrfs/ioctl: store btrfs_uring_encoded_data in io_btrfs_cmd
  io_uring/cmd: introduce IORING_URING_CMD_REISSUE flag
  io_uring/zcrx: account area memory
  io_uring: export io_[un]account_mem
  io_uring/net: Support multishot receive len cap
  io_uring: deduplicate wakeup handling
  io_uring/net: cast min_not_zero() type
  io_uring/poll: cleanup apoll freeing
  io_uring/net: allow multishot receive per-invocation cap
  io_uring/net: move io_sr_msg->retry_flags to io_sr_msg->flags
  io_uring/net: use passed in 'len' in io_recv_buf_select()
  io_uring/zcrx: prepare fallback for larger pages
  io_uring/zcrx: assert area type in io_zcrx_iov_page
  io_uring/zcrx: allocate sgtable for umem areas
  io_uring/zcrx: introduce io_populate_area_dma
  ...
2025-07-28 16:30:12 -07:00
Linus Torvalds
7879d7aff0 Merge tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc VFS updates from Christian Brauner:
 "This contains the usual selections of misc updates for this cycle.

  Features:

   - Add ext4 IOCB_DONTCACHE support

     This refactors the address_space_operations write_begin() and
     write_end() callbacks to take const struct kiocb * as their first
     argument, allowing IOCB flags such as IOCB_DONTCACHE to propagate
     to the filesystem's buffered I/O path.

     Ext4 is updated to implement handling of the IOCB_DONTCACHE flag
     and advertises support via the FOP_DONTCACHE file operation flag.

     Additionally, the i915 driver's shmem write paths are updated to
     bypass the legacy write_begin/write_end interface in favor of
     directly calling write_iter() with a constructed synchronous kiocb.
     Another i915 change replaces a manual write loop with
     kernel_write() during GEM shmem object creation.

  Cleanups:

   - don't duplicate vfs_open() in kernel_file_open()

   - proc_fd_getattr(): don't bother with S_ISDIR() check

   - fs/ecryptfs: replace snprintf with sysfs_emit in show function

   - vfs: Remove unnecessary list_for_each_entry_safe() from
     evict_inodes()

   - filelock: add new locks_wake_up_waiter() helper

   - fs: Remove three arguments from block_write_end()

   - VFS: change old_dir and new_dir in struct renamedata to dentrys

   - netfs: Remove unused declaration netfs_queue_write_request()

  Fixes:

   - eventpoll: Fix semi-unbounded recursion

   - eventpoll: fix sphinx documentation build warning

   - fs/read_write: Fix spelling typo

   - fs: annotate data race between poll_schedule_timeout() and
     pollwake()

   - fs/pipe: set FMODE_NOWAIT in create_pipe_files()

   - docs/vfs: update references to i_mutex to i_rwsem

   - fs/buffer: remove comment about hard sectorsize

   - fs/buffer: remove the min and max limit checks in __getblk_slow()

   - fs/libfs: don't assume blocksize <= PAGE_SIZE in
     generic_check_addressable

   - fs_context: fix parameter name in infofc() macro

   - fs: Prevent file descriptor table allocations exceeding INT_MAX"

* tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits)
  netfs: Remove unused declaration netfs_queue_write_request()
  eventpoll: fix sphinx documentation build warning
  ext4: support uncached buffered I/O
  mm/pagemap: add write_begin_get_folio() helper function
  fs: change write_begin/write_end interface to take struct kiocb *
  drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter
  drm/i915: Use kernel_write() in shmem object create
  eventpoll: Fix semi-unbounded recursion
  vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes()
  fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable
  fs/buffer: remove the min and max limit checks in __getblk_slow()
  fs: Prevent file descriptor table allocations exceeding INT_MAX
  fs: Remove three arguments from block_write_end()
  fs/ecryptfs: replace snprintf with sysfs_emit in show function
  fs: annotate suspected data race between poll_schedule_timeout() and pollwake()
  docs/vfs: update references to i_mutex to i_rwsem
  fs/buffer: remove comment about hard sectorsize
  fs_context: fix parameter name in infofc() macro
  VFS: change old_dir and new_dir in struct renamedata to dentrys
  proc_fd_getattr(): don't bother with S_ISDIR() check
  ...
2025-07-28 11:22:56 -07:00
Pavel Begunkov
d9f595b9a6 io_uring/zcrx: fix leaking pages on sg init fail
If sg_alloc_table_from_pages() fails, io_import_umem() returns without
cleaning up pinned pages first. Fix it.

Fixes: b84621d96e ("io_uring/zcrx: allocate sgtable for umem areas")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9fd94d1bc8c316611eccfec7579799182ff3fb0a.1753091564.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-21 06:47:45 -06:00
Pavel Begunkov
6bbd3411ff io_uring/zcrx: don't leak pages on account failure
Someone needs to release pinned pages in io_import_umem() if accounting
fails. Assign them to the area but return an error, the following
io_zcrx_free_area() will clean them up.

Fixes: 262ab20518 ("io_uring/zcrx: account area memory")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e19f283a912f200c0d427e376cb789fc3f3d69bc.1753091564.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-21 06:47:45 -06:00
Pavel Begunkov
720df2310b io_uring/zcrx: fix null ifq on area destruction
Dan reports that ifq can be null when infering arguments for
io_unaccount_mem() from io_zcrx_free_area(). Fix it by always setting a
correct ifq.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202507180628.gBxrOgqr-lkp@intel.com/
Fixes: 262ab20518 ("io_uring/zcrx: account area memory")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20670d163bb90dba2a81a4150f1125603cefb101.1753091564.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-21 06:47:45 -06:00
Linus Torvalds
e347810e84 Merge tag 'io_uring-6.16-20250718' of git://git.kernel.dk/linux
Pull io_uring fixes from Jens Axboe:

 - dmabug offset fix for zcrx

 - Fix for the POLLERR connect work around handling

* tag 'io_uring-6.16-20250718' of git://git.kernel.dk/linux:
  io_uring/poll: fix POLLERR handling
  io_uring/zcrx: disallow user selected dmabuf offset and size
2025-07-18 12:21:26 -07:00
Caleb Sander Mateos
2e6dbb25ea io_uring/cmd: remove struct io_uring_cmd_data
There are no more users of struct io_uring_cmd_data and its op_data
field. Remove it to shave 8 bytes from struct io_async_cmd and eliminate
a store and load for every uring_cmd.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Acked-by: David Sterba <dsterba@suse.com>
Link: https://lore.kernel.org/r/20250708202212.2851548-5-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-18 12:34:56 -06:00
Caleb Sander Mateos
733c43f1df io_uring/cmd: introduce IORING_URING_CMD_REISSUE flag
Add a flag IORING_URING_CMD_REISSUE that ->uring_cmd() implementations
can use to tell whether this is the first or subsequent issue of the
uring_cmd. This will allow ->uring_cmd() implementations to store
information in the io_uring_cmd's pdu across issues.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Acked-by: David Sterba <dsterba@suse.com>
Link: https://lore.kernel.org/r/20250708202212.2851548-3-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-18 12:34:56 -06:00
Pavel Begunkov
262ab20518 io_uring/zcrx: account area memory
zcrx areas can be quite large and need to be accounted and checked
against RLIMIT_MEMLOCK. In practise it shouldn't be a big issue as
the inteface already requires cap_net_admin.

Cc: stable@vger.kernel.org
Fixes: cf96310c5f ("io_uring/zcrx: add io_zcrx_area")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4b53f0c575bd062f63d12bec6cac98037fc66aeb.1752699568.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-16 16:23:28 -06:00
Pavel Begunkov
11fbada718 io_uring: export io_[un]account_mem
Export pinned memory accounting helpers, they'll be used by zcrx
shortly.

Cc: stable@vger.kernel.org
Fixes: cf96310c5f ("io_uring/zcrx: add io_zcrx_area")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9a61e54bd89289b39570ae02fe620e12487439e4.1752699568.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-16 16:23:28 -06:00
Pavel Begunkov
c7cafd5b81 io_uring/poll: fix POLLERR handling
8c8492ca64 ("io_uring/net: don't retry connect operation on EPOLLERR")
is a little dirty hack that
1) wrongfully assumes that POLLERR equals to a failed request, which
breaks all POLLERR users, e.g. all error queue recv interfaces.
2) deviates the connection request behaviour from connect(2), and
3) racy and solved at a wrong level.

Nothing can be done with 2) now, and 3) is beyond the scope of the
patch. At least solve 1) by moving the hack out of generic poll handling
into io_connect().

Cc: stable@vger.kernel.org
Fixes: 8c8492ca64 ("io_uring/net: don't retry connect operation on EPOLLERR")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3dc89036388d602ebd84c28e5042e457bdfc952b.1752682444.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-16 10:28:28 -06:00
Norman Maurer
0ebc9a7ecf io_uring/net: Support multishot receive len cap
At the moment its very hard to do fine grained backpressure when using
multishot as the kernel might produce a lot of completions before the
user has a chance to cancel a previous submitted multishot recv.

This change adds support to issue a multishot recv that is capped by a
len, which means the kernel will only rearm until X amount of data is
received. When the limit is reached the completion will signal to the
user that a re-arm needs to happen manually by not setting the IORING_CQE_F_MORE
flag.

Signed-off-by: Norman Maurer <norman_maurer@apple.com>
Link: https://lore.kernel.org/r/20250715140249.31186-1-norman_maurer@apple.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-16 08:28:11 -06:00
Jens Axboe
8723c146ad io_uring: deduplicate wakeup handling
Both io_poll_wq_wake() and io_cqring_wake() contain the exact same code,
and most of the comment in the latter applies equally to both.

Move the test and wakeup handling into a basic helper that they can both
use, and move part of the comment that applies generically to this new
helper.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-15 12:20:06 -06:00
Jens Axboe
b1915b18e1 io_uring/net: cast min_not_zero() type
kernel test robot reports that xtensa complains about different
signedness for a min_not_zero() comparison. Cast the int part to size_t
to avoid this issue.

Fixes: e227c8cdb4 ("io_uring/net: use passed in 'len' in io_recv_buf_select()")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507150504.zO5FsCPm-lkp@intel.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-14 16:36:08 -06:00
Pavel Begunkov
08ca1409c4 io_uring/zcrx: disallow user selected dmabuf offset and size
zcrx shouldn't be so frivolous about cutting a dmabuf sgtable and taking
a subrange into it, the dmabuf layer might be not expecting that. It
shouldn't be a problem for now, but since the zcrx dmabuf support is new
and there shouldn't be any real users, let's play safe and reject user
provided ranges into dmabufs. Also, it shouldn't be needed as userspace
should size them appropriately.

Fixes: a5c98e9424 ("io_uring/zcrx: dmabuf backed zerocopy receive")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/be899f1afed32053eb2e2079d0da241514674aca.1752443579.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-14 08:54:43 -06:00
Jens Axboe
6e4098382b io_uring/poll: cleanup apoll freeing
No point having REQ_F_POLLED in both IO_REQ_CLEAN_FLAGS and in
IO_REQ_CLEAN_SLOW_FLAGS, and having both io_free_batch_list() and then
io_clean_op() check for it and clean it.

Move REQ_F_POLLED to IO_REQ_CLEAN_SLOW_FLAGS and drop it from
IO_REQ_CLEAN_FLAGS, and have only io_free_batch_list() do the check and
freeing.

Link: https://lore.kernel.org/io-uring/20250712000344.1579663-2-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-12 15:03:05 -06:00
Linus Torvalds
cb3002e0e9 Merge tag 'io_uring-6.16-20250710' of git://git.kernel.dk/linux
Pull io_uring fixes from Jens Axboe:

 - Remove a pointless warning in the zcrx code

 - Fix for MSG_RING commands, where the allocated io_kiocb
   needs to be freed under RCU as well

 - Revert the work-around we had in place for the anon inodes
   pretending to be regular files. Since that got reworked
   upstream, the work-around is no longer needed

* tag 'io_uring-6.16-20250710' of git://git.kernel.dk/linux:
  Revert "io_uring: gate REQ_F_ISREG on !S_ANON_INODE as well"
  io_uring/msg_ring: ensure io_kiocb freeing is deferred for RCU
  io_uring/zcrx: fix pp destruction warnings
2025-07-11 10:29:30 -07:00
Jens Axboe
6a8afb9fff io_uring/net: allow multishot receive per-invocation cap
If an application is handling multiple receive streams using recv
multishot, then the amount of retries and buffer peeking for multishot
and bundles can process too much per socket before moving on. This isn't
directly controllable by the application. By default, io_uring will
retry a recv MULTISHOT_MAX_RETRY (32) times, if the socket keeps having
data to receive. And if using bundles, then each bundle peek will
potentially map up to PEEK_MAX_IMPORT (256) iovecs of data. Once these
limits are hit, then a requeue operation will be done, where the request
will get retried after other pending requests have had a time to get
executed.

Add support for capping the per-invocation receive length, before a
requeue condition is considered for each receive. This is done by setting
sqe->mshot_len to the byte value. For example, if this is set to 1024,
then each receive will be requeued by 1024 bytes received.

Link: https://lore.kernel.org/io-uring/20250709203420.1321689-4-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-10 11:54:33 -06:00
Jens Axboe
3919b69593 io_uring/net: move io_sr_msg->retry_flags to io_sr_msg->flags
There's plenty of space left, as sr->flags is a 16-bit type. The UAPI
bits are the lower 8 bits, as that's all that sqe->ioprio can carry in
the SQE anyway. Use a few of the upper 8 bits for internal uses, rather
than have two separate flags entries.

Link: https://lore.kernel.org/io-uring/20250709203420.1321689-2-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-10 11:54:22 -06:00
Jens Axboe
e227c8cdb4 io_uring/net: use passed in 'len' in io_recv_buf_select()
len is a pointer to the desired len, use that rather than grab it from
sr->len again. No functional changes as of this patch, but it does
prepare io_recv_buf_select() for getting passed in a value that differs
from sr->len.

Link: https://lore.kernel.org/io-uring/20250709203420.1321689-3-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-10 11:54:08 -06:00
Pavel Begunkov
e67645bb7f io_uring/zcrx: prepare fallback for larger pages
io_zcrx_copy_chunk() processes one page at a time, which won't be
sufficient when the net_iov size grows. Introduce a structure keeping
the target niov page and other parameters, it's more convenient and can
be reused later. And add a helper function that can efficient copy
buffers of an arbitrary length. For 64bit archs the loop inside should
be compiled out.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e84bc705a4e1edeb9aefff470d96558d8232388f.1751466461.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-08 11:59:56 -06:00
Pavel Begunkov
1b4dc1ff0a io_uring/zcrx: assert area type in io_zcrx_iov_page
Add a simple debug assertion to io_zcrx_iov_page() making it's not
trying to return pages for a dmabuf area.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c3c30a926a18436a399a1768f3cc86c76cd17fa7.1751466461.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-08 11:59:56 -06:00
Pavel Begunkov
b84621d96e io_uring/zcrx: allocate sgtable for umem areas
Currently, dma addresses for umem areas are stored directly in niovs.
It's memory efficient but inconvenient. I need a better format 1) to
share code with dmabuf areas, and 2) for disentangling page, folio and
niov sizes. dmabuf already provides sg_table, create one for user memory
as well.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: David Wei <dw@davidwei.uk>
Link: https://lore.kernel.org/r/f3c15081827c1bf5427d3a2e693bc526476b87ee.1751466461.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-08 11:59:56 -06:00
Pavel Begunkov
54e89a93ef io_uring/zcrx: introduce io_populate_area_dma
Add a helper that initialises page-pool dma addresses from a sg table.
It'll be reused in following patches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: David Wei <dw@davidwei.uk>
Link: https://lore.kernel.org/r/a8972a77be9b5675abc585d6e2e6e30f9c7dbd85.1751466461.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-08 11:59:56 -06:00
Pavel Begunkov
06897ddfc5 io_uring/zcrx: return error from io_zcrx_map_area_*
io_zcrx_map_area_*() helpers return the number of processed niovs, which
we use to unroll some of the mappings for user memory areas. It's
unhandy, and dmabuf doesn't care about it. Return an error code instead
and move failure partial unmapping into io_zcrx_map_area_umem().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: David Wei <dw@davidwei.uk>
Link: https://lore.kernel.org/r/42668e82be3a84b07ee8fc76d1d6d5ac0f137fe5.1751466461.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-08 11:59:56 -06:00