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>
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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
...
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>
This reverts commit 6f11adcc6f.
The problematic commit was fixed in mainline, so the work-around in
io_uring can be removed at this point. Anonymous inodes no longer
pretend to be regular files after:
1e7ab6f678 ("anon_inode: rework assertions")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge in 6.16 io_uring fixes, to avoid clashes with pending net and
settings changes.
* io_uring-6.16:
io_uring: gate REQ_F_ISREG on !S_ANON_INODE as well
io_uring/kbuf: flag partial buffer mappings
io_uring/net: mark iov as dynamically allocated even for single segments
io_uring: fix resource leak in io_import_dmabuf()
io_uring: don't assume uaddr alignment in io_vec_fill_bvec
io_uring/rsrc: don't rely on user vaddr alignment
io_uring/rsrc: fix folio unpinning
io_uring: make fallocate be hashed work
io_uring marks a request as dealing with a regular file on S_ISREG. This
drives things like retries on short reads or writes, which is generally
not expected on a regular file (or bdev). Applications tend to not
expect that, so io_uring tries hard to ensure it doesn't deliver short
IO on regular files.
However, a recent commit added S_IFREG to anonymous inodes. When
io_uring is used to read from various things that are backed by anon
inodes, like eventfd, timerfd, etc, then it'll now all of a sudden wait
for more data when rather than deliver what was read or written in a
single operation. This breaks applications that issue reads on anon
inodes, if they ask for more data than a single read delivers.
Add a check for !S_ANON_INODE as well before setting REQ_F_ISREG to
prevent that.
Cc: Christian Brauner <brauner@kernel.org>
Cc: stable@vger.kernel.org
Link: https://github.com/ghostty-org/ghostty/discussions/7720
Fixes: cfd86ef7e8 ("anon_inode: use a proper mode internally")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a helper for posting 32 byte CQEs in a multishot mode and add a cmd
helper on top. As it specifically works with requests, the helper ignore
the passed in cqe->user_data and sets it to the one stored in the
request.
The command helper is only valid with multishot requests.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c29d7720c16e1f981cfaa903df187138baa3946b.1750065793.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Will be called by the core of io_uring, if inline issue is not going
to be tried for a request. Opcodes can define this handler to defer
copying of SQE data that should remain stable.
Only called if IO_URING_F_INLINE is set. If it isn't set, then there's a
bug in the core handling of this, and -EFAULT will be returned instead
to terminate the request. This will trigger a WARN_ON_ONCE(). Don't
expect this to ever trigger, and down the line this can be removed.
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Set when the execution of the request is done inline from the system
call itself. Any deferred issue will never have this flag set.
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In preparation for needing to shift NVMe passthrough to always use
task_work for polled IO completions, ensure that those are suitably
run at exit time. See commit:
9ce6c9875f ("nvme: always punt polled uring_cmd end_io work to task_work")
for details on why that is necessary.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The sqpoll thread is dereferenced with rcu read protection in one place,
so it needs to be annotated as an __rcu type, and should consistently
use rcu helpers for access and assignment to make sparse happy.
Since most of the accesses occur under the sqd->lock, we can use
rcu_dereference_protected() without declaring an rcu read section.
Provide a simple helper to get the thread from a locked context.
Fixes: ac0b8b327a ("io_uring: fix use-after-free of sq->thread in __io_uring_show_fdinfo()")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20250611205343.1821117-1-kbusch@meta.com
[axboe: fold in fix for register.c]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Inflight marking is used so that do_exit() -> io_uring_files_cancel()
will find requests with files that reference an io_uring instance,
so they can get appropriately canceled before the files go away.
However, it's also called before the mm goes away.
Mark futex/futexv wait requests as being inflight, so that
io_uring_files_cancel() will prune them. This ensures that the mm stays
alive, which is important as an exiting mm will also free the futex
private hash buckets. An io_uring futex request with FUTEX2_PRIVATE
set relies on those being alive until the request has completed. A
recent commit added these futex private hashes, which get killed when
the mm goes away.
Fixes: 80367ad01d ("futex: Add basic infrastructure for local task local hash")
Link: https://lore.kernel.org/io-uring/38053.1749045482@localhost/
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.16/io_uring-20250523' of git://git.kernel.dk/linux
Pull io_uring updates from Jens Axboe:
- Avoid indirect function calls in io-wq for executing and freeing
work.
The design of io-wq is such that it can be a generic mechanism, but
as it's just used by io_uring now, may as well avoid these indirect
calls
- Clean up registered buffers for networking
- Add support for IORING_OP_PIPE. Pretty straight forward, allows
creating pipes with io_uring, particularly useful for having these be
instantiated as direct descriptors
- Clean up the coalescing support fore registered buffers
- Add support for multiple interface queues for zero-copy rx
networking. As this feature was merged for 6.15 it supported just a
single ifq per ring
- Clean up the eventfd support
- Add dma-buf support to zero-copy rx
- Clean up and improving the request draining support
- Clean up provided buffer support, most notably with an eye toward
making the legacy support less intrusive
- Minor fdinfo cleanups, dropping support for dumping what credentials
are registered
- Improve support for overflow CQE handling, getting rid of GFP_ATOMIC
for allocating overflow entries where possible
- Improve detection of cases where io-wq doesn't need to spawn a new
worker unnecessarily
- Various little cleanups
* tag 'for-6.16/io_uring-20250523' of git://git.kernel.dk/linux: (59 commits)
io_uring/cmd: warn on reg buf imports by ineligible cmds
io_uring/io-wq: only create a new worker if it can make progress
io_uring/io-wq: ignore non-busy worker going to sleep
io_uring/io-wq: move hash helpers to the top
trace/io_uring: fix io_uring_local_work_run ctx documentation
io_uring: finish IOU_OK -> IOU_COMPLETE transition
io_uring: add new helpers for posting overflows
io_uring: pass in struct io_big_cqe to io_alloc_ocqe()
io_uring: make io_alloc_ocqe() take a struct io_cqe pointer
io_uring: split alloc and add of overflow
io_uring: open code io_req_cqe_overflow()
io_uring/fdinfo: get rid of dumping credentials
io_uring/fdinfo: only compile if CONFIG_PROC_FS is set
io_uring/kbuf: unify legacy buf provision and removal
io_uring/kbuf: refactor __io_remove_buffers
io_uring/kbuf: don't compute size twice on prep
io_uring/kbuf: drop extra vars in io_register_pbuf_ring
io_uring/kbuf: use mem_is_zero()
io_uring/kbuf: account ring io_buffer_list memory
io_uring: drain based on allocates reqs
...
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Merge tag 'for-6.16/block-20250523' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- ublk updates:
- Add support for updating the size of a ublk instance
- Zero-copy improvements
- Auto-registering of buffers for zero-copy
- Series simplifying and improving GET_DATA and request lookup
- Series adding quiesce support
- Lots of selftests additions
- Various cleanups
- NVMe updates via Christoph:
- add per-node DMA pools and use them for PRP/SGL allocations
(Caleb Sander Mateos, Keith Busch)
- nvme-fcloop refcounting fixes (Daniel Wagner)
- support delayed removal of the multipath node and optionally
support the multipath node for private namespaces (Nilay Shroff)
- support shared CQs in the PCI endpoint target code (Wilfred
Mallawa)
- support admin-queue only authentication (Hannes Reinecke)
- use the crc32c library instead of the crypto API (Eric Biggers)
- misc cleanups (Christoph Hellwig, Marcelo Moreira, Hannes
Reinecke, Leon Romanovsky, Gustavo A. R. Silva)
- MD updates via Yu:
- Fix that normal IO can be starved by sync IO, found by mkfs on
newly created large raid5, with some clean up patches for bdev
inflight counters
- Clean up brd, getting rid of atomic kmaps and bvec poking
- Add loop driver specifically for zoned IO testing
- Eliminate blk-rq-qos calls with a static key, if not enabled
- Improve hctx locking for when a plug has IO for multiple queues
pending
- Remove block layer bouncing support, which in turn means we can
remove the per-node bounce stat as well
- Improve blk-throttle support
- Improve delay support for blk-throttle
- Improve brd discard support
- Unify IO scheduler switching. This should also fix a bunch of lockdep
warnings we've been seeing, after enabling lockdep support for queue
freezing/unfreezeing
- Add support for block write streams via FDP (flexible data placement)
on NVMe
- Add a bunch of block helpers, facilitating the removal of a bunch of
duplicated boilerplate code
- Remove obsolete BLK_MQ pci and virtio Kconfig options
- Add atomic/untorn write support to blktrace
- Various little cleanups and fixes
* tag 'for-6.16/block-20250523' of git://git.kernel.dk/linux: (186 commits)
selftests: ublk: add test for UBLK_F_QUIESCE
ublk: add feature UBLK_F_QUIESCE
selftests: ublk: add test case for UBLK_U_CMD_UPDATE_SIZE
traceevent/block: Add REQ_ATOMIC flag to block trace events
ublk: run auto buf unregisgering in same io_ring_ctx with registering
io_uring: add helper io_uring_cmd_ctx_handle()
ublk: remove io argument from ublk_auto_buf_reg_fallback()
ublk: handle ublk_set_auto_buf_reg() failure correctly in ublk_fetch()
selftests: ublk: add test for covering UBLK_AUTO_BUF_REG_FALLBACK
selftests: ublk: support UBLK_F_AUTO_BUF_REG
ublk: support UBLK_AUTO_BUF_REG_FALLBACK
ublk: register buffer to local io_uring with provided buf index via UBLK_F_AUTO_BUF_REG
ublk: prepare for supporting to register request buffer automatically
ublk: convert to refcount_t
selftests: ublk: make IO & device removal test more stressful
nvme: rename nvme_mpath_shutdown_disk to nvme_mpath_remove_disk
nvme: introduce multipath_always_on module param
nvme-multipath: introduce delayed removal of the multipath head node
nvme-pci: derive and better document max segments limits
nvme-pci: use struct_size for allocation struct nvme_dev
...
IOU_COMPLETE is more descriptive, in that it explicitly says that the
return value means "please post a completion for this request". This
patch completes the transition from IOU_OK to IOU_COMPLETE, replacing
existing IOU_OK users.
This is a purely mechanical change.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Leaving the CQ critical section in the middle of a overflow flushing
can cause cqe reordering since the cache cq pointers are reset and any
new cqe emitters that might get called in between are not going to be
forced into io_cqe_cache_refill().
Fixes: eac2ca2d68 ("io_uring: check if we need to reschedule during overflow flush")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/90ba817f1a458f091f355f407de1c911d2b93bbf.1747483784.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add two helpers, one for posting overflows for lockless_cq rings, and
one for non-lockless_cq rings. The former can allocate sanely with
GFP_KERNEL, but needs to grab the completion lock for posting, while the
latter must do non-sleeping allocs as it already holds the completion
lock.
While at it, mark the overflow handling functions as __cold as well, as
they should not generally be called during normal operations of the
ring.
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rather than pass extra1/extra2 separately, just pass in the (now) named
io_big_cqe struct instead. The callers that don't use/support CQE32 will
now just pass a single NULL, rather than two seperate mystery zero
values.
Move the clearing of the big_cqe elements into io_alloc_ocqe() as well,
so it can get moved out of the generic code.
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The number of arguments to io_alloc_ocqe() is a bit unwieldy. Make it
take a struct io_cqe pointer rather than three separate CQE args. One
path already has that readily available, add an io_init_cqe() helper for
the remaining two.
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a new helper, io_alloc_ocqe(), that simply allocates and fills an
overflow entry. Then it can get done outside of the locking section,
and hence use more appropriate gfp_t allocation flags rather than always
default to GFP_ATOMIC.
Inspired by a previous series from Pavel:
https://lore.kernel.org/io-uring/cover.1747209332.git.asml.silence@gmail.com/
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A preparation patch, just open code io_req_cqe_overflow().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge in 6.15 io_uring fixes, mostly so that the fdinfo changes can
get easily extended without causing merge conflicts.
* io_uring-6.15:
io_uring/fdinfo: grab ctx->uring_lock around io_uring_show_fdinfo()
io_uring/memmap: don't use page_address() on a highmem page
io_uring/uring_cmd: fix hybrid polling initialization issue
io_uring/sqpoll: Increase task_work submission batch size
io_uring: ensure deferred completions are flushed for multishot
io_uring: always arm linked timeouts prior to issue
io_uring/fdinfo: annotate racy sq/cq head/tail reads
io_uring: fix 'sync' handling of io_fallback_tw()
io_uring: don't duplicate flushing in io_req_post_cqe
Don't rely on CQ sequence numbers for draining, as it has become messy
and needs cq_extra adjustments. Instead, base it on the number of
allocated requests and only allow flushing when all requests are in the
drain list.
As a result, cq_extra is gone, no overhead for its accounting in aux cqe
posting, less bloating as it was inlined before, and it's in general
simpler than trying to track where we should bump it and where it should
be put back like in cases of overflow. Also, it'll likely help with
cleaning and unifying some of the CQ posting helpers.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/46ece1e34320b046c06fee2498d6b4cd12a700f2.1746788718.git.asml.silence@gmail.com
Link: https://lore.kernel.org/r/24497b04b004bceada496033d3c9d09ff8e81ae9.1746944903.git.asml.silence@gmail.com
[axboe: fold in fix from link2]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_queue_deferred() is not tolerant to spurious calls not completing
some requests. You can have an inflight drain-marked request and another
request that came after and got queued into the drain list. Now, if
io_queue_deferred() is called before the first request completes, it'll
check the 2nd req with req_need_defer(), find that there is no drain
flag set, and queue it for execution.
To make io_queue_deferred() work, it should at least check sequences for
the first request, and then we need also need to check if there is
another drain request creating another bubble.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/972bde11b7d4ef25b3f5e3fd34f80e4d2aa345b8.1746788718.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Multishot normally uses io_req_post_cqe() to post completions, but when
stopping it, it may finish up with a deferred completion. This is fine,
except if another multishot event triggers before the deferred completions
get flushed. If this occurs, then CQEs may get reordered in the CQ ring,
as new multishot completions get posted before the deferred ones are
flushed. This can cause confusion on the application side, if strict
ordering is required for the use case.
When multishot posting via io_req_post_cqe(), flush any pending deferred
completions first, if any.
Cc: stable@vger.kernel.org # 6.1+
Reported-by: Norman Maurer <norman_maurer@apple.com>
Reported-by: Christian Mazakas <christian.mazakas@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It'd be nice to hide details of how rsrc nodes are used by a request
from rsrc.c, specifically which request fields store them, and what bits
are signifying if there is a node in a request. It rather belong to
generic request handling, so move the helper to io_uring.c. While doing
so remove clearing of ->buf_node as it's controlled by REQ_F_BUF_NODE
and doesn't require zeroing.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bb73fb42baf825edb39344365aff48cdfdd4c692.1746533789.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Apart from setting ->ctx, io_preinit_req() zeroes a bunch of fields of a
request, from which only ->file_node is mandatory. Remove the function
and zero the entire request on first allocation. With that, we also need
to initialise ->ctx every time, which might be a good thing for
performance as now we're likely overwriting the entire cache line, and
so it can write combined and avoid RMW.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ba5485dc913f1e275862ce88f5169d4ac4a33836.1746533807.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Allow userspace to pass a per-I/O write stream in the SQE:
__u8 write_stream;
The __u8 type matches the size the filesystems and block layer support.
Application can query the supported values from the block devices
max_write_streams sysfs attribute. Unsupported values are ignored by
file operations that do not support write streams or rejected with an
error by those that support them.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20250506121732.8211-7-joshi.k@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There are a few spots where linked timeouts are armed, and not all of
them adhere to the pre-arm, attempt issue, post-arm pattern. This can
be problematic if the linked request returns that it will trigger a
callback later, and does so before the linked timeout is fully armed.
Consolidate all the linked timeout handling into __io_issue_sqe(),
rather than have it spread throughout the various issue entry points.
Cc: stable@vger.kernel.org
Link: https://github.com/axboe/liburing/issues/1390
Reported-by: Chase Hiltz <chase@path.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A previous commit added a 'sync' parameter to io_fallback_tw(), which if
true, means the caller wants to wait on the fallback thread handling it.
But the logic is somewhat messed up, ensure that ctxs are swapped and
flushed appropriately.
Cc: stable@vger.kernel.org
Fixes: dfbe5561ae ("io_uring: flush offloaded and delayed task_work on exit")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There are two helpers here, one assigns and increments the node ref
count, and the other is simply a wrapper around that for the buffer node
handling.
The buffer node assignment benefits from checking and setting
REQ_F_BUF_NODE together, otherwise stalls have been observed on setting
that flag later in the process. Hence re-do it so that it's set when
checked, and cleared in case of (unlikely) failure. With that, the
buffer node helper can go, and then drop the generic
io_req_assign_rsrc_node() helper as well as there's only a single user
of it left at that point.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
struct io_wq stores do_work and free_work function pointers which are
called on each work item. But these function pointers are always set to
io_wq_submit_work and io_wq_free_work, respectively. So remove these
function pointers and just call the functions directly.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://lore.kernel.org/r/20250329161527.3281314-1-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_uring always switches requests to atomic refcounting for iowq
execution before there is any parallilism by setting REQ_F_REFCOUNT,
and the flag is not cleared until the request completes. That should be
fine as long as the compiler doesn't make up a non existing value for
the flags, however KCSAN still complains when the request owner changes
oter flag bits:
BUG: KCSAN: data-race in io_req_task_cancel / io_wq_free_work
...
read to 0xffff888117207448 of 8 bytes by task 3871 on cpu 0:
req_ref_put_and_test io_uring/refs.h:22 [inline]
Skip REQ_F_REFCOUNT checks for iowq, we know it's set.
Reported-by: syzbot+903a2ad71fb3f1e47cf5@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d880bc27fb8c3209b54641be4ff6ac02b0e5789a.1743679736.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.15/io_uring-reg-vec-20250327' of git://git.kernel.dk/linux
Pull more io_uring updates from Jens Axboe:
"Final separate updates for io_uring.
This started out as a series of cleanups improvements and improvements
for registered buffers, but as the last series of the io_uring changes
for 6.15, it also collected a few fixes for the other branches on top:
- Add support for vectored fixed/registered buffers.
Previously only single segments have been supported for commands,
now vectored variants are supported as well. This series includes
networking and file read/write support.
- Small series unifying return codes across multi and single shot.
- Small series cleaning up registerd buffer importing.
- Adding support for vectored registered buffers for uring_cmd.
- Fix for io-wq handling of command reissue.
- Various little fixes and tweaks"
* tag 'for-6.15/io_uring-reg-vec-20250327' of git://git.kernel.dk/linux: (25 commits)
io_uring/net: fix io_req_post_cqe abuse by send bundle
io_uring/net: use REQ_F_IMPORT_BUFFER for send_zc
io_uring: move min_events sanitisation
io_uring: rename "min" arg in io_iopoll_check()
io_uring: open code __io_post_aux_cqe()
io_uring: defer iowq cqe overflow via task_work
io_uring: fix retry handling off iowq
io_uring/net: only import send_zc buffer once
io_uring/cmd: introduce io_uring_cmd_import_fixed_vec
io_uring/cmd: add iovec cache for commands
io_uring/cmd: don't expose entire cmd async data
io_uring: rename the data cmd cache
io_uring: rely on io_prep_reg_vec for iovec placement
io_uring: introduce io_prep_reg_iovec()
io_uring: unify STOP_MULTISHOT with IOU_OK
io_uring: return -EAGAIN to continue multishot
io_uring: cap cached iovec/bvec size
io_uring/net: implement vectored reg bufs for zctx
io_uring/net: convert to struct iou_vec
io_uring/net: pull vec alloc out of msghdr import
...
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Merge tag 'for-6.15/io_uring-rx-zc-20250325' of git://git.kernel.dk/linux
Pull io_uring zero-copy receive support from Jens Axboe:
"This adds support for zero-copy receive with io_uring, enabling fast
bulk receive of data directly into application memory, rather than
needing to copy the data out of kernel memory.
While this version only supports host memory as that was the initial
target, other memory types are planned as well, with notably GPU
memory coming next.
This work depends on some networking components which were queued up
on the networking side, but have now landed in your tree.
This is the work of Pavel Begunkov and David Wei. From the v14 posting:
'We configure a page pool that a driver uses to fill a hw rx queue
to hand out user pages instead of kernel pages. Any data that ends
up hitting this hw rx queue will thus be dma'd into userspace
memory directly, without needing to be bounced through kernel
memory. 'Reading' data out of a socket instead becomes a
_notification_ mechanism, where the kernel tells userspace where
the data is. The overall approach is similar to the devmem TCP
proposal
This relies on hw header/data split, flow steering and RSS to
ensure packet headers remain in kernel memory and only desired
flows hit a hw rx queue configured for zero copy. Configuring this
is outside of the scope of this patchset.
We share netdev core infra with devmem TCP. The main difference is
that io_uring is used for the uAPI and the lifetime of all objects
are bound to an io_uring instance. Data is 'read' using a new
io_uring request type. When done, data is returned via a new shared
refill queue. A zero copy page pool refills a hw rx queue from this
refill queue directly. Of course, the lifetime of these data
buffers are managed by io_uring rather than the networking stack,
with different refcounting rules.
This patchset is the first step adding basic zero copy support. We
will extend this iteratively with new features e.g. dynamically
allocated zero copy areas, THP support, dmabuf support, improved
copy fallback, general optimisations and more'
In a local setup, I was able to saturate a 200G link with a single CPU
core, and at netdev conf 0x19 earlier this month, Jamal reported
188Gbit of bandwidth using a single core (no HT, including soft-irq).
Safe to say the efficiency is there, as bigger links would be needed
to find the per-core limit, and it's considerably more efficient and
faster than the existing devmem solution"
* tag 'for-6.15/io_uring-rx-zc-20250325' of git://git.kernel.dk/linux:
io_uring/zcrx: add selftest case for recvzc with read limit
io_uring/zcrx: add a read limit to recvzc requests
io_uring: add missing IORING_MAP_OFF_ZCRX_REGION in io_uring_mmap
io_uring: Rename KConfig to Kconfig
io_uring/zcrx: fix leaks on failed registration
io_uring/zcrx: recheck ifq on shutdown
io_uring/zcrx: add selftest
net: add documentation for io_uring zcrx
io_uring/zcrx: add copy fallback
io_uring/zcrx: throttle receive requests
io_uring/zcrx: set pp memory provider for an rx queue
io_uring/zcrx: add io_recvzc request
io_uring/zcrx: dma-map area for the device
io_uring/zcrx: implement zerocopy receive pp memory provider
io_uring/zcrx: grab a net device
io_uring/zcrx: add io_zcrx_area
io_uring/zcrx: add interface queue and refill queue
[ 114.987980][ T5313] WARNING: CPU: 6 PID: 5313 at io_uring/io_uring.c:872 io_req_post_cqe+0x12e/0x4f0
[ 114.991597][ T5313] RIP: 0010:io_req_post_cqe+0x12e/0x4f0
[ 115.001880][ T5313] Call Trace:
[ 115.002222][ T5313] <TASK>
[ 115.007813][ T5313] io_send+0x4fe/0x10f0
[ 115.009317][ T5313] io_issue_sqe+0x1a6/0x1740
[ 115.012094][ T5313] io_wq_submit_work+0x38b/0xed0
[ 115.013223][ T5313] io_worker_handle_work+0x62a/0x1600
[ 115.013876][ T5313] io_wq_worker+0x34f/0xdf0
As the comment states, io_req_post_cqe() should only be used by
multishot requests, i.e. REQ_F_APOLL_MULTISHOT, which bundled sends are
not. Add a flag signifying whether a request wants to post multiple
CQEs. Eventually REQ_F_APOLL_MULTISHOT should imply the new flag, but
that's left out for simplicity.
Cc: stable@vger.kernel.org
Fixes: a05d1f625c ("io_uring/net: support bundles for send")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8b611dbb54d1cd47a88681f5d38c84d0c02bc563.1743067183.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.15/io_uring-20250322' of git://git.kernel.dk/linux
Pull io_uring updates from Jens Axboe:
"This is the first of the io_uring pull requests for the 6.15 merge
window, there will be others once the net tree has gone in. This
contains:
- Cleanup and unification of cancelation handling across various
request types.
- Improvement for bundles, supporting them both for incrementally
consumed buffers, and for non-multishot requests.
- Enable toggling of using iowait while waiting on io_uring events or
not. Unfortunately this is still tied with CPU frequency boosting
on short waits, as the scheduler side has not been very receptive
to splitting the (useless) iowait stat from the cpufreq implied
boost.
- Add support for kbuf nodes, enabling zero-copy support for the ublk
block driver.
- Various cleanups for resource node handling.
- Series greatly cleaning up the legacy provided (non-ring based)
buffers. For years, we've been pushing the ring provided buffers as
the way to go, and that is what people have been using. Reduce the
complexity and code associated with legacy provided buffers.
- Series cleaning up the compat handling.
- Series improving and cleaning up the recvmsg/sendmsg iovec and msg
handling.
- Series of cleanups for io-wq.
- Start adding a bunch of selftests. The liburing repository
generally carries feature and regression tests for everything, but
at least for ublk initially, we'll try and go the route of having
it in selftests as well. We'll see how this goes, might decide to
migrate more tests this way in the future.
- Various little cleanups and fixes"
* tag 'for-6.15/io_uring-20250322' of git://git.kernel.dk/linux: (108 commits)
selftests: ublk: add stripe target
selftests: ublk: simplify loop io completion
selftests: ublk: enable zero copy for null target
selftests: ublk: prepare for supporting stripe target
selftests: ublk: move common code into common.c
selftests: ublk: increase max buffer size to 1MB
selftests: ublk: add single sqe allocator helper
selftests: ublk: add generic_01 for verifying sequential IO order
selftests: ublk: fix starting ublk device
io_uring: enable toggle of iowait usage when waiting on CQEs
selftests: ublk: fix write cache implementation
selftests: ublk: add variable for user to not show test result
selftests: ublk: don't show `modprobe` failure
selftests: ublk: add one dependency header
io_uring/kbuf: enable bundles for incrementally consumed buffers
Revert "io_uring/rsrc: simplify the bvec iter count calculation"
selftests: ublk: improve test usability
selftests: ublk: add stress test for covering IO vs. killing ublk server
selftests: ublk: add one stress test for covering IO vs. removing device
selftests: ublk: load/unload ublk_drv when preparing & cleaning up tests
...
