Commit Graph

802 Commits

Author SHA1 Message Date
Pavel Begunkov
4130b49991 io_uring/rsrc: inline io_rsrc_put_work()
io_rsrc_put_work() is simple enough to be open coded into its only
caller.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1b36dd46766ced39a9b160767babfa2fce07b8f8.1681822823.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-18 19:38:26 -06:00
Pavel Begunkov
26147da37f io_uring/rsrc: add empty flag in rsrc_node
Unless a node was flushed by io_rsrc_ref_quiesce(), it'll carry a
resource. Replace ->inline_items with an empty flag, which is
initialised to false and only raised in io_rsrc_ref_quiesce().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/75d384c9d2252e12af73b9cf8a44e1699106aeb1.1681822823.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-18 19:38:26 -06:00
Pavel Begunkov
c376644fb9 io_uring/rsrc: merge nodes and io_rsrc_put
struct io_rsrc_node carries a number of resources represented by struct
io_rsrc_put. That was handy before for sync overhead ammortisation, but
all complexity is gone and nodes are simple and lightweight. Let's
allocate a separate node for each resource.

Nodes and io_rsrc_put and not much different in size, and former are
cached, so node allocation should work better. That also removes some
overhead for nested iteration in io_rsrc_node_ref_zero() /
__io_rsrc_put_work().

Another reason for the patch is that it greatly reduces complexity
by moving io_rsrc_node_switch[_start]() inside io_queue_rsrc_removal(),
so users don't have to care about it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c7d3a45b30cc14cd93700a710dd112edc703db98.1681822823.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-18 19:38:26 -06:00
Pavel Begunkov
63fea89027 io_uring/rsrc: infer node from ctx on io_queue_rsrc_removal
For io_queue_rsrc_removal() we should always use the current active rsrc
node, don't pass it directly but let the function grab it from the
context.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d15939b4afea730978b4925685c2577538b823bb.1681822823.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-18 19:38:26 -06:00
Pavel Begunkov
2e6f45ac0e io_uring/rsrc: remove unused io_rsrc_node::llist
->llist was needed for rsrc node destruction offload, which is removed
now. Get rid of the unused field.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8e7d764c3f947489fde88d0927c3060d2e1bb599.1681822823.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-18 19:38:26 -06:00
Pavel Begunkov
c899a5d7d0 io_uring/rsrc: refactor io_queue_rsrc_removal
We can queue up a rsrc into a list in io_queue_rsrc_removal() while
allocating io_rsrc_put and so simplify the function.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/36bd708ee25c0e2e7992dc19b17db166eea9ac40.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:45:55 -06:00
Pavel Begunkov
c87fd583f3 io_uring/rsrc: simplify single file node switching
At maximum io_install_fixed_file() removes only one file, so no need to
keep needs_switch state and we can call io_rsrc_node_switch() right after
removal.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/37cfb46f46160f81dced79f646e97db608994574.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:45:49 -06:00
Pavel Begunkov
9a57fffedc io_uring/rsrc: clean up __io_sqe_buffers_update()
Inline offset variable, so we don't use it without subjecting it to
array_index_nospec() first.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/77936d9ed23755588810c5eafcea7e1c3b90e3cd.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:44:57 -06:00
Pavel Begunkov
2f2af35f8e io_uring/rsrc: inline switch_start fast path
Inline the part of io_rsrc_node_switch_start() that checks whether the
cache is empty or not, as most of the times it will have some number of
entries in there.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9619c1717a0e01f22c5fce2f1ba2735f804da0f2.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:44:57 -06:00
Pavel Begunkov
0b222eeb65 io_uring/rsrc: remove rsrc_data refs
Instead of waiting for rsrc_data->refs to be downed to zero, check
whether there are rsrc nodes queued for completion, that's easier then
maintaining references.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8e33fd143d83e11af3e386aea28eb6d6c6a1be10.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:44:57 -06:00
Pavel Begunkov
7d481e0356 io_uring/rsrc: fix DEFER_TASKRUN rsrc quiesce
For io_rsrc_ref_quiesce() to progress it should execute all task_work
items, including deferred ones. However, currently nobody would wake us,
and so let's set ctx->cq_wait_nr, so io_req_local_work_add() would wake
us up.

Fixes: c0e0d6ba25 ("io_uring: add IORING_SETUP_DEFER_TASKRUN")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f1a90d1bc5ebf096475b018fed52e54f3b89d4af.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:44:57 -06:00
Pavel Begunkov
4ea15b56f0 io_uring/rsrc: use wq for quiescing
Replace completions with waitqueues for rsrc data quiesce, the main
wakeup condition is when data refs hit zero. Note that data refs are
only changes under ->uring_lock, so we prepare before mutex_unlock()
reacquire it after taking the lock back. This change will be needed
in the next patch.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1d0dbc74b3b4fd67c8f01819e680c5e0da252956.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:44:57 -06:00
Pavel Begunkov
eef81fcaa6 io_uring/rsrc: refactor io_rsrc_ref_quiesce
Refactor io_rsrc_ref_quiesce() by moving the first mutex_unlock(),
so we don't have to have a second mutex_unlock() further in the loop.
It prepares us to the next patch.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/65bc876271fb16bf550a53a4c76c91aacd94e52e.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:44:57 -06:00
Pavel Begunkov
c732ea242d io_uring/rsrc: remove io_rsrc_node::done
Kill io_rsrc_node::node and check refs instead, it's set when the nodes
refcount hits zero, and it won't change afterwards.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bbde361f4010f7e8bf196f1ecca27a763b79926f.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:44:57 -06:00
Pavel Begunkov
953c37e066 io_uring/rsrc: use nospec'ed indexes
We use array_index_nospec() for registered buffer indexes, but don't use
it while poking into rsrc tags, fix that.

Fixes: 634d00df5e ("io_uring: add full-fledged dynamic buffers support")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f02fafc5a9c0dd69be2b0618c38831c078232ff0.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:44:57 -06:00
Pavel Begunkov
519760df25 io_uring/notif: add constant for ubuf_info flags
Add a constant IO_NOTIF_UBUF_FLAGS for struct ubuf_info flags that
notifications use. That should minimise merge conflicts for planned
changes touching both io_uring and net at the same time.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-15 14:21:04 -06:00
Linus Torvalds
1c6492d646 io_uring-6.3-2023-04-14
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Merge tag 'io_uring-6.3-2023-04-14' of git://git.kernel.dk/linux

Pull io_uring fix from Jens Axboe:
 "Just a small tweak to when task_work needs redirection, marked for
  stable as well"

* tag 'io_uring-6.3-2023-04-14' of git://git.kernel.dk/linux:
  io_uring: complete request via task work in case of DEFER_TASKRUN
2023-04-15 10:29:53 -07:00
Ming Lei
860e1c7f8b io_uring: complete request via task work in case of DEFER_TASKRUN
So far io_req_complete_post() only covers DEFER_TASKRUN by completing
request via task work when the request is completed from IOWQ.

However, uring command could be completed from any context, and if io
uring is setup with DEFER_TASKRUN, the command is required to be
completed from current context, otherwise wait on IORING_ENTER_GETEVENTS
can't be wakeup, and may hang forever.

The issue can be observed on removing ublk device, but turns out it is
one generic issue for uring command & DEFER_TASKRUN, so solve it in
io_uring core code.

Fixes: e6aeb2721d ("io_uring: complete all requests in task context")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-block/b3fc9991-4c53-9218-a8cc-5b4dd3952108@kernel.dk/
Reported-by: Jens Axboe <axboe@kernel.dk>
Cc: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-14 06:38:23 -06:00
Jakub Kicinski
800e68c44f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

tools/testing/selftests/net/config
  62199e3f16 ("selftests: net: Add VXLAN MDB test")
  3a0385be13 ("selftests: add the missing CONFIG_IP_SCTP in net config")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-13 16:04:28 -07:00
Pavel Begunkov
d581076b6a io_uring/rsrc: extract SCM file put helper
SCM file accounting is a slow path and is only used for UNIX files.
Extract a helper out of io_rsrc_file_put() that does the SCM
unaccounting.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/58cc7bffc2ee96bec8c2b89274a51febcbfa5556.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:09:41 -06:00
Pavel Begunkov
2933ae6eaa io_uring/rsrc: refactor io_rsrc_node_switch
We use io_rsrc_node_switch() coupled with io_rsrc_node_switch_start()
for a bunch of cases including initialising ctx->rsrc_node, i.e. by
passing NULL instead of rsrc_data. Leave it to only deal with actual
node changing.

For that, first remove it from io_uring_create() and add a function
allocating the first node. Then also remove all calls to
io_rsrc_node_switch() from files/buffers register as we already have a
node installed and it does essentially nothing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d146fe306ff98b1a5a60c997c252534f03d423d7.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:09:41 -06:00
Pavel Begunkov
13c223962e io_uring/rsrc: zero node's rsrc data on alloc
struct io_rsrc_node::rsrc_data field is initialised on rsrc removal and
shouldn't be used before that, still let's play safe and zero the field
on alloc.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/09bd03cedc8da8a7974c5e6e4bf0489fd16593ab.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:09:41 -06:00
Pavel Begunkov
528407b1e0 io_uring/rsrc: consolidate node caching
We store one pre-allocated rsrc node in ->rsrc_backup_node, merge it
with ->rsrc_node_cache.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6d5410e51ccd29be7a716be045b51d6b371baef6.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:09:41 -06:00
Pavel Begunkov
786788a8cf io_uring/rsrc: add lockdep checks
Add a lockdep chek to make sure that file and buffer updates hold
->uring_lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/961bbe6e433ec9bc0375127f23468b37b729df99.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:09:41 -06:00
Pavel Begunkov
8ce4269eee io_uring: add irq lockdep checks
We don't post CQEs from the IRQ context, add a check catching that.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f23f7a24dbe8027b3d37873fece2b6488f878b31.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:09:41 -06:00
Pavel Begunkov
ceac766a55 io_uring/kbuf: remove extra ->buf_ring null check
The kernel test robot complains about __io_remove_buffers().

io_uring/kbuf.c:221 __io_remove_buffers() warn: variable dereferenced
before check 'bl->buf_ring' (see line 219)

That check is not needed as ->buf_ring will always be set, so we can
remove it and so silence the warning.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9a632bbf749d9d911e605255652ce08d18e7d2c6.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:09:41 -06:00
Pavel Begunkov
8b1df11f97 io_uring: shut io_prep_async_work warning
io_uring/io_uring.c:432 io_prep_async_work() error: we previously
assumed 'req->file' could be null (see line 425).

Even though it's a false positive as there will not be REQ_F_ISREG set
without a file, let's add a simple check to make the kernel test robot
happy. We don't care about performance here, but assumingly it'll be
optimised out by the compiler.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a6cfbe92c74b789c0b4f046f7f98d19b1ca2e5b7.1681210788.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:09:41 -06:00
Jens Axboe
27a67079c0 io_uring/uring_cmd: take advantage of completion batching
We know now what the completion context is for the uring_cmd completion
handling, so use that to have io_req_task_complete() decide what the
best way to complete the request is. This allows batching of the posted
completions if we have multiple pending, rather than always doing them
one-by-one.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-12 12:07:36 -06:00
Linus Torvalds
d3f05a4c42 io_uring-6.3-2023-04-06
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Merge tag 'io_uring-6.3-2023-04-06' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe:
 "Just two minor fixes for provided buffers - one where we could
  potentially leak a buffer, and one where the returned values was
  off-by-one in some cases"

* tag 'io_uring-6.3-2023-04-06' of git://git.kernel.dk/linux:
  io_uring: fix memory leak when removing provided buffers
  io_uring: fix return value when removing provided buffers
2023-04-08 11:34:17 -07:00
Pavel Begunkov
360cd42c4e io_uring: optimise io_req_local_work_add
Chains of memory accesses are never good for performance.
The req->task->io_uring->in_cancel in io_req_local_work_add() is there
so that when a task is exiting via io_uring_try_cancel_requests() and
starts waiting for completions, it gets woken up by every new task_work
item queued.

Do a little trick by announcing waiting in io_uring_try_cancel_requests(),
making io_req_local_work_add() wake us up. We also need to check for
deferred tw items after prepare_to_wait(TASK_INTERRUPTIBLE);

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fb11597e9bbcb365901824f8c5c2cf0d6ee100d0.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:24:36 -06:00
Pavel Begunkov
c66ae3ec38 io_uring: refactor __io_cq_unlock_post_flush()
Separate ->task_complete path in __io_cq_unlock_post_flush().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/baa9b8d822f024e4ee01c40209dbbe38d9c8c11d.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:23:28 -06:00
Pavel Begunkov
8751d15426 io_uring: reduce scheduling due to tw
Every task_work will try to wake the task to be executed, which causes
excessive scheduling and additional overhead. For some tw it's
justified, but others won't do much but post a single CQE.

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

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d2b77e99d1e86624d8a69f7037d764b739dcd225.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:23:28 -06:00
Pavel Begunkov
5150940079 io_uring: inline llist_add()
We'll need to grab some information from the previous request in the tw
list, inline llist_add(), it'll be used in the following patch.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f0165493af7b379943c792114b972f331e7d7d10.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:23:28 -06:00
Pavel Begunkov
8501fe70ae io_uring: add tw add flags
We pass 'allow_local' into io_req_task_work_add() but will need more
flags. Replace it with a flags bit field and name this allow_local
flag.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4c0f01e7ef4e6feebfb199093cc995af7a19befa.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:23:28 -06:00
Pavel Begunkov
6e7248adf8 io_uring: refactor io_cqring_wake()
Instead of smp_mb() + __io_cqring_wake() in __io_cq_unlock_post_flush()
use equivalent io_cqring_wake(). With that we can clean it up further
and remove __io_cqring_wake().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/662ee5d898168ac206be06038525e97b64072a46.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:23:28 -06:00
Pavel Begunkov
d73a572df2 io_uring: optimize local tw add ctx pinning
We currently pin the ctx for io_req_local_work_add() with
percpu_ref_get/put, which implies two rcu_read_lock/unlock pairs and some
extra overhead on top in the fast path. Replace it with a pure rcu read
and let io_ring_exit_work() synchronise against it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/cbdfcb6b232627f30e9e50ef91f13c4f05910247.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:23:10 -06:00
Pavel Begunkov
ab1c590f5c io_uring: move pinning out of io_req_local_work_add
Move ctx pinning from io_req_local_work_add() to the caller, looks
better and makes working with the code a bit easier.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/49c0dbed390b0d6d04cb942dd3592879fd5bfb1b.1680782017.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-06 16:22:07 -06:00
Jakub Kicinski
d9c960675a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

drivers/net/ethernet/google/gve/gve.h
  3ce9345580 ("gve: Secure enough bytes in the first TX desc for all TCP pkts")
  75eaae158b ("gve: Add XDP DROP and TX support for GQI-QPL format")
https://lore.kernel.org/all/20230406104927.45d176f5@canb.auug.org.au/
https://lore.kernel.org/all/c5872985-1a95-0bc8-9dcc-b6f23b439e9d@tessares.net/

Adjacent changes:

net/can/isotp.c
  051737439e ("can: isotp: fix race between isotp_sendsmg() and isotp_release()")
  96d1c81e6a ("can: isotp: add module parameter for maximum pdu size")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-06 12:01:20 -07:00
Jens Axboe
758d5d64b6 io_uring/uring_cmd: assign ioucmd->cmd at async prep time
Rather than check this in the fast path issue, it makes more sense to
just assign the copy of the data when we're setting it up anyway. This
makes the code a bit cleaner, and removes the need for this check in
the issue path.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-05 09:30:18 -06:00
Pavel Begunkov
69bbc6ade9 io_uring/rsrc: add custom limit for node caching
The number of entries in the rsrc node cache is limited to 512, which
still seems unnecessarily large. Add per cache thresholds and set to
to 32 for the rsrc node cache.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d0cd538b944dac0bf878e276fc0199f21e6bccea.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
757ef4682b io_uring/rsrc: optimise io_rsrc_data refcounting
Every struct io_rsrc_node takes a struct io_rsrc_data reference, which
means all rsrc updates do 2 extra atomics. Replace atomics refcounting
with a int as it's all done under ->uring_lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e73c3d6820cf679532696d790b5b8fae23537213.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
1f2c8f610a io_uring/rsrc: add lockdep sanity checks
We should hold ->uring_lock while putting nodes with io_put_rsrc_node(),
add a lockdep check for that.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b50d5f156ac41450029796738c1dfd22a521df7a.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
9eae8655f9 io_uring/rsrc: cache struct io_rsrc_node
Add allocation cache for struct io_rsrc_node, it's always allocated and
put under ->uring_lock, so it doesn't need any extra synchronisation
around caches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/252a9d9ef9654e6467af30fdc02f57c0118fb76e.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
36b9818a5a io_uring/rsrc: don't offload node free
struct delayed_work rsrc_put_work was previously used to offload node
freeing because io_rsrc_node_ref_zero() was previously called by RCU in
the IRQ context. Now, as percpu refcounting is gone, we can do it
eagerly at the spot without pushing it to a worker.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/13fb1aac1e8d068ad8fd4a0c6d0d157ab61b90c0.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
ff7c75ecaa io_uring/rsrc: optimise io_rsrc_put allocation
Every io_rsrc_node keeps a list of items to put, and all entries are
kmalloc()'ed. However, it's quite often to queue up only one entry per
node, so let's add an inline entry there to avoid extra allocations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c482c1c652c45c85ac52e67c974bc758a50fed5f.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
c824986c11 io_uring/rsrc: rename rsrc_list
We have too many "rsrc" around which makes the name of struct
io_rsrc_node::rsrc_list confusing. The field is responsible for keeping
a list of files or buffers, so call it item_list and add comments
around.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3e34d4dfc1fdbb6b520f904ee6187c2ccf680efe.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
0a4813b1ab io_uring/rsrc: kill rsrc_ref_lock
We use ->rsrc_ref_lock spinlock to protect ->rsrc_ref_list in
io_rsrc_node_ref_zero(). Now we removed pcpu refcounting, which means
io_rsrc_node_ref_zero() is not executed from the irq context as an RCU
callback anymore, and we also put it under ->uring_lock.
io_rsrc_node_switch(), which queues up nodes into the list, is also
protected by ->uring_lock, so we can safely get rid of ->rsrc_ref_lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6b60af883c263551190b526a55ff2c9d5ae07141.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
ef8ae64ffa io_uring/rsrc: protect node refs with uring_lock
Currently, for nodes we have an atomic counter and some cached
(non-atomic) refs protected by uring_lock. Let's put all ref
manipulations under uring_lock and get rid of the atomic part.
It's free as in all cases we care about we already hold the lock.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/25b142feed7d831008257d90c8b17c0115d4fc15.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
03adabe81a io_uring: io_free_req() via tw
io_free_req() is not often used but nevertheless problematic as there is
no way to know the current context, it may be used from the submission
path or even by an irq handler. Push it to a fresh context using
task_work.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3a92fe80bb068757e51aaa0b105cfbe8f5dfee9e.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
2ad4c6d080 io_uring: don't put nodes under spinlocks
io_req_put_rsrc() doesn't need any locking, so move it out of
a spinlock section in __io_req_complete_post() and adjust helpers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d5b87a5f31270dade6805f7acafc4cc34b84b241.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
8e15c0e71b io_uring/rsrc: keep cached refs per node
We cache refs of the current node (i.e. ctx->rsrc_node) in
ctx->rsrc_cached_refs. We'll be moving away from atomics, so move the
cached refs in struct io_rsrc_node for now. It's a prep patch and
shouldn't change anything in practise.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9edc3669c1d71b06c2dca78b2b2b8bb9292738b9.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Pavel Begunkov
b8fb5b4fdd io_uring/rsrc: use non-pcpu refcounts for nodes
One problem with the current rsrc infra is that often updates will
generates lots of rsrc nodes, each carry pcpu refs. That takes quite a
lot of memory, especially if there is a stall, and takes lots of CPU
cycles. Only pcpu allocations takes >50 of CPU with a naive benchmark
updating files in a loop.

Replace pcpu refs with normal refcounting. There is already a hot path
avoiding atomics / refs, but following patches will further improve it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e9ed8a9457b331a26555ff9443afc64cdaab7247.1680576071.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-04 09:30:39 -06:00
Jens Axboe
e3ef728ff0 io_uring: cap io_sqring_entries() at SQ ring size
We already do this manually for the !SQPOLL case, do it in general and
we can also dump the ugly min3() in io_submit_sqes().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:15 -06:00
Jens Axboe
2ad57931db io_uring: rename trace_io_uring_submit_sqe() tracepoint
It has nothing to do with the SQE at this point, it's a request
submission. While in there, get rid of the 'force_nonblock' argument
which is also dead, as we only pass in true.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:15 -06:00
Pavel Begunkov
a282967c84 io_uring: encapsulate task_work state
For task works we're passing around a bool pointer for whether the
current ring is locked or not, let's wrap it in a structure, that
will make it more opaque preventing abuse and will also help us
to pass more info in the future if needed.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1ecec9483d58696e248d1bfd52cf62b04442df1d.1679931367.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:15 -06:00
Pavel Begunkov
13bfa6f15d io_uring: remove extra tw trylocks
Before cond_resched()'ing in handle_tw_list() we also drop the current
ring context, and so the next loop iteration will need to pick/pin a new
context and do trylock.

The chunk removed by this patch was intended to be an optimisation
covering exactly this case, i.e. retaking the lock after reschedule, but
in reality it's skipped for the first iteration after resched as
described and will keep hammering the lock if it's contended.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1ecec9483d58696e248d1bfd52cf62b04442df1d.1679931367.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:15 -06:00
Jens Axboe
07d99096e1 io_uring/io-wq: drop outdated comment
Since the move to PF_IO_WORKER, we don't juggle memory context manually
anymore. Remove that outdated part of the comment for __io_worker_idle().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:15 -06:00
Gabriel Krisman Bertazi
eb47943f22 io-wq: Drop struct io_wqe
Since commit 0654b05e7e65 ("io_uring: One wqe per wq"), we have just a
single io_wqe instance embedded per io_wq.  Drop the extra structure in
favor of accessing struct io_wq directly, cleaning up quite a bit of
dereferences and backpointers.

No functional changes intended.  Tested with liburing's testsuite
and mmtests performance microbenchmarks.  I didn't observe any
performance regressions.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230322011628.23359-2-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:15 -06:00
Gabriel Krisman Bertazi
dfd63baf89 io-wq: Move wq accounting to io_wq
Since we now have a single io_wqe per io_wq instead of per-node, and in
preparation to its removal, move the accounting into the parent
structure.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230322011628.23359-2-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:14 -06:00
Jens Axboe
fcb46c0ccc io_uring/kbuf: disallow mapping a badly aligned provided ring buffer
On at least parisc, we have strict requirements on how we virtually map
an address that is shared between the application and the kernel. On
these platforms, IOU_PBUF_RING_MMAP should be used when setting up a
shared ring buffer for provided buffers. If the application is mapping
these pages and asking the kernel to pin+map them as well, then we have
no control over what virtual address we get in the kernel.

For that case, do a sanity check if SHM_COLOUR is defined, and disallow
the mapping request. The application must fall back to using
IOU_PBUF_RING_MMAP for this case, and liburing will do that transparently
with the set of helpers that it has.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:14 -06:00
Breno Leitao
e1fe7ee885 io_uring: Add KASAN support for alloc_caches
Add support for KASAN in the alloc_caches (apoll and netmsg_cache).
Thus, if something touches the unused caches, it will raise a KASAN
warning/exception.

It poisons the object when the object is put to the cache, and unpoisons
it when the object is gotten or freed.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230223164353.2839177-2-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:14 -06:00
Breno Leitao
efba1a9e65 io_uring: Move from hlist to io_wq_work_node
Having cache entries linked using the hlist format brings no benefit, and
also requires an unnecessary extra pointer address per cache entry.

Use the internal io_wq_work_node single-linked list for the internal
alloc caches (async_msghdr and async_poll)

This is required to be able to use KASAN on cache entries, since we do
not need to touch unused (and poisoned) cache entries when adding more
entries to the list.

Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230223164353.2839177-2-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:12 -06:00
Breno Leitao
da64d6db3b io_uring: One wqe per wq
Right now io_wq allocates one io_wqe per NUMA node.  As io_wq is now
bound to a task, the task basically uses only the NUMA local io_wqe, and
almost never changes NUMA nodes, thus, the other wqes are mostly
unused.

Allocate just one io_wqe embedded into io_wq, and uses all possible cpus
(cpu_possible_mask) in the io_wqe->cpumask.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230310201107.4020580-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:21 -06:00
Jens Axboe
c56e022c0a io_uring: add support for user mapped provided buffer ring
The ring mapped provided buffer rings rely on the application allocating
the memory for the ring, and then the kernel will map it. This generally
works fine, but runs into issues on some architectures where we need
to be able to ensure that the kernel and application virtual address for
the ring play nicely together. This at least impacts architectures that
set SHM_COLOUR, but potentially also anyone setting SHMLBA.

To use this variant of ring provided buffers, the application need not
allocate any memory for the ring. Instead the kernel will do so, and
the allocation must subsequently call mmap(2) on the ring with the
offset set to:

	IORING_OFF_PBUF_RING | (bgid << IORING_OFF_PBUF_SHIFT)

to get a virtual address for the buffer ring. Normally the application
would allocate a suitable piece of memory (and correctly aligned) and
simply pass that in via io_uring_buf_reg.ring_addr and the kernel would
map it.

Outside of the setup differences, the kernel allocate + user mapped
provided buffer ring works exactly the same.

Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:21 -06:00
Jens Axboe
81cf17cd3a io_uring/kbuf: rename struct io_uring_buf_reg 'pad' to'flags'
In preparation for allowing flags to be set for registration, rename
the padding and use it for that.

Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:21 -06:00
Jens Axboe
25a2c188a0 io_uring/kbuf: add buffer_list->is_mapped member
Rather than rely on checking buffer_list->buf_pages or ->buf_nr_pages,
add a separate member that tracks if this is a ring mapped provided
buffer list or not.

Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:20 -06:00
Jens Axboe
ba56b63242 io_uring/kbuf: move pinning of provided buffer ring into helper
In preparation for allowing the kernel to allocate the provided buffer
rings and have the application mmap it instead, abstract out the
current method of pinning and mapping the user allocated ring.

No functional changes intended in this patch.

Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:20 -06:00
Helge Deller
d808459b2e io_uring: Adjust mapping wrt architecture aliasing requirements
Some architectures have memory cache aliasing requirements (e.g. parisc)
if memory is shared between userspace and kernel. This patch fixes the
kernel to return an aliased address when asked by userspace via mmap().

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:20 -06:00
Jens Axboe
d4755e1538 io_uring: avoid hashing O_DIRECT writes if the filesystem doesn't need it
io_uring hashes writes to a given file/inode so that it can serialize
them. This is useful if the file system needs exclusive access to the
file to perform the write, as otherwise we end up with a ton of io-wq
threads trying to lock the inode at the same time. This can cause
excessive system time.

But if the file system has flagged that it supports parallel O_DIRECT
writes, then there's no need to serialize the writes. Check for that
through FMODE_DIO_PARALLEL_WRITE and don't hash it if we don't need to.

In a basic test of 8 threads writing to a file on XFS on a gen2 Optane,
with each thread writing in 4k chunks, it improves performance from
~1350K IOPS (or ~5290MiB/sec) to ~1410K IOPS (or ~5500MiB/sec).

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:20 -06:00
Wojciech Lukowicz
b4a72c0589 io_uring: fix memory leak when removing provided buffers
When removing provided buffers, io_buffer structs are not being disposed
of, leading to a memory leak. They can't be freed individually, because
they are allocated in page-sized groups. They need to be added to some
free list instead, such as io_buffers_cache. All callers already hold
the lock protecting it, apart from when destroying buffers, so had to
extend the lock there.

Fixes: cc3cec8367 ("io_uring: speedup provided buffer handling")
Signed-off-by: Wojciech Lukowicz <wlukowicz01@gmail.com>
Link: https://lore.kernel.org/r/20230401195039.404909-2-wlukowicz01@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-01 16:52:12 -06:00
Wojciech Lukowicz
c0921e51da io_uring: fix return value when removing provided buffers
When a request to remove buffers is submitted, and the given number to be
removed is larger than available in the specified buffer group, the
resulting CQE result will be the number of removed buffers + 1, which is
1 more than it should be.

Previously, the head was part of the list and it got removed after the
loop, so the increment was needed. Now, the head is not an element of
the list, so the increment shouldn't be there anymore.

Fixes: dbc7d452e7 ("io_uring: manage provided buffers strictly ordered")
Signed-off-by: Wojciech Lukowicz <wlukowicz01@gmail.com>
Link: https://lore.kernel.org/r/20230401195039.404909-2-wlukowicz01@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-01 16:52:12 -06:00
Linus Torvalds
f3fa7f026e io_uring-6.3-2023-03-30
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Merge tag 'io_uring-6.3-2023-03-30' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe:

 - Fix a regression with the poll retry, introduced in this merge window
   (me)

 - Fix a regression with the alloc cache not decrementing the member
   count on removal. Also a regression from this merge window (Pavel)

 - Fix race around rsrc node grabbing (Pavel)

* tag 'io_uring-6.3-2023-03-30' of git://git.kernel.dk/linux:
  io_uring: fix poll/netmsg alloc caches
  io_uring/rsrc: fix rogue rsrc node grabbing
  io_uring/poll: clear single/double poll flags on poll arming
2023-03-31 12:30:13 -07:00
Jakub Kicinski
79548b7984 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

drivers/net/ethernet/mediatek/mtk_ppe.c
  3fbe4d8c0e ("net: ethernet: mtk_eth_soc: ppe: add support for flow accounting")
  924531326e ("net: ethernet: mtk_eth_soc: add missing ppe cache flush when deleting a flow")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-30 14:43:03 -07:00
Jens Axboe
95e49cf837 iov_iter: add iter_iov_addr() and iter_iov_len() helpers
These just return the address and length of the current iovec segment
in the iterator. Convert existing iov_iter_iovec() users to use them
instead of getting a copy of the current vec.

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

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

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-30 08:12:29 -06:00
Pavel Begunkov
fd30d1cdcc io_uring: fix poll/netmsg alloc caches
We increase cache->nr_cached when we free into the cache but don't
decrease when we take from it, so in some time we'll get an empty
cache with cache->nr_cached larger than IO_ALLOC_CACHE_MAX, that fails
io_alloc_cache_put() and effectively disables caching.

Fixes: 9b797a37c4 ("io_uring: add abstraction around apoll cache")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-30 06:53:42 -06:00
Pavel Begunkov
4ff0b50de8 io_uring/rsrc: fix rogue rsrc node grabbing
We should not be looking at ctx->rsrc_node and anyhow modifying the node
without holding uring_lock, grabbing references in such a way is not
safe either.

Cc: stable@vger.kernel.org
Fixes: 5106dd6e74 ("io_uring: propagate issue_flags state down to file assignment")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1202ede2d7bb90136e3482b2b84aad9ed483e5d6.1680098433.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-29 09:23:46 -06:00
Jens Axboe
005308f7bd io_uring/poll: clear single/double poll flags on poll arming
Unless we have at least one entry queued, then don't call into
io_poll_remove_entries(). Normally this isn't possible, but if we
retry poll then we can have ->nr_entries cleared again as we're
setting it up. If this happens for a poll retry, then we'll still have
at least REQ_F_SINGLE_POLL set. io_poll_remove_entries() then thinks
it has entries to remove.

Clear REQ_F_SINGLE_POLL and REQ_F_DOUBLE_POLL unconditionally when
arming a poll request.

Fixes: c16bda3759 ("io_uring/poll: allow some retries for poll triggering spuriously")
Cc: stable@vger.kernel.org
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-28 07:09:01 -06:00
Linus Torvalds
83511470af block-6.3-2023-03-24
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Merge tag 'block-6.3-2023-03-24' of git://git.kernel.dk/linux

Pull block fixes from Jens Axboe:

 - NVMe pull request via Christoph:
     - Send Identify with CNS 06h only to I/O controllers (Martin
       George)
     - Fix nvme_tcp_term_pdu to match spec (Caleb Sander)

 - Pass in issue_flags for uring_cmd, so the end_io handlers don't need
   to assume what the right context is (me)

 - Fix for ublk, marking it as LIVE before adding it to avoid races on
   the initial IO (Ming)

* tag 'block-6.3-2023-03-24' of git://git.kernel.dk/linux:
  nvme-tcp: fix nvme_tcp_term_pdu to match spec
  nvme: send Identify with CNS 06h only to I/O controllers
  block/io_uring: pass in issue_flags for uring_cmd task_work handling
  block: ublk_drv: mark device as LIVE before adding disk
2023-03-24 14:10:39 -07:00
Savino Dicanosa
02a4d923e4 io_uring/rsrc: fix null-ptr-deref in io_file_bitmap_get()
When fixed files are unregistered, file_alloc_end and alloc_hint
are not cleared. This can later cause a NULL pointer dereference in
io_file_bitmap_get() if auto index selection is enabled via
IORING_FILE_INDEX_ALLOC:

[    6.519129] BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
[    6.541468] RIP: 0010:_find_next_zero_bit+0x1a/0x70
[...]
[    6.560906] Call Trace:
[    6.561322]  <TASK>
[    6.561672]  io_file_bitmap_get+0x38/0x60
[    6.562281]  io_fixed_fd_install+0x63/0xb0
[    6.562851]  ? __pfx_io_socket+0x10/0x10
[    6.563396]  io_socket+0x93/0xf0
[    6.563855]  ? __pfx_io_socket+0x10/0x10
[    6.564411]  io_issue_sqe+0x5b/0x3d0
[    6.564914]  io_submit_sqes+0x1de/0x650
[    6.565452]  __do_sys_io_uring_enter+0x4fc/0xb20
[    6.566083]  ? __do_sys_io_uring_register+0x11e/0xd80
[    6.566779]  do_syscall_64+0x3c/0x90
[    6.567247]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
[...]

To fix the issue, set file alloc range and alloc_hint to zero after
file tables are freed.

Cc: stable@vger.kernel.org
Fixes: 4278a0deb1 ("io_uring: defer alloc_hint update to io_file_bitmap_set()")
Signed-off-by: Savino Dicanosa <sd7.dev@pm.me>
[axboe: add explicit bitmap == NULL check as well]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-22 11:04:55 -06:00
Jens Axboe
74e2e17ee1 io_uring/net: avoid sending -ECONNABORTED on repeated connection requests
Since io_uring does nonblocking connect requests, if we do two repeated
ones without having a listener, the second will get -ECONNABORTED rather
than the expected -ECONNREFUSED. Treat -ECONNABORTED like a normal retry
condition if we're nonblocking, if we haven't already seen it.

Cc: stable@vger.kernel.org
Fixes: 3fb1bd6881 ("io_uring/net: handle -EINPROGRESS correct for IORING_OP_CONNECT")
Link: https://github.com/axboe/liburing/issues/828
Reported-by: Hui, Chunyang <sanqian.hcy@antgroup.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-20 20:44:45 -06:00
Jens Axboe
9d2789ac9d block/io_uring: pass in issue_flags for uring_cmd task_work handling
io_uring_cmd_done() currently assumes that the uring_lock is held
when invoked, and while it generally is, this is not guaranteed.
Pass in the issue_flags associated with it, so that we have
IO_URING_F_UNLOCKED available to be able to lock the CQ ring
appropriately when completing events.

Cc: stable@vger.kernel.org
Fixes: ee692a21e9 ("fs,io_uring: add infrastructure for uring-cmd")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-20 20:01:25 -06:00
Keith Busch
54bdd67d0f blk-mq: remove hybrid polling
io_uring provides the only way user space can poll completions, and that
always sets BLK_POLL_NOSLEEP. This effectively makes hybrid polling dead
code, so remove it and everything supporting it.

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

Fixes: 9650b453a3 ("block: ignore RWF_HIPRI hint for sync dio")
Fixes: d729cf9acb ("io_uring: don't sleep when polling for I/O")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20230320194926.3353144-1-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-20 15:30:03 -06:00
Jakub Kicinski
1118aa4c70 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
net/wireless/nl80211.c
  b27f07c50a ("wifi: nl80211: fix puncturing bitmap policy")
  cbbaf2bb82 ("wifi: nl80211: add a command to enable/disable HW timestamping")
https://lore.kernel.org/all/20230314105421.3608efae@canb.auug.org.au

tools/testing/selftests/net/Makefile
  62199e3f16 ("selftests: net: Add VXLAN MDB test")
  13715acf8a ("selftest: Add test for bind() conflicts.")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-17 16:29:25 -07:00
Pavel Begunkov
d2acf78908 io_uring/rsrc: fix folio accounting
| BUG: Bad page state in process kworker/u8:0  pfn:5c001
| page:00000000bfda61c8 refcount:0 mapcount:0 mapping:0000000000000000 index:0x20001 pfn:0x5c001
| head:0000000011409842 order:9 entire_mapcount:0 nr_pages_mapped:0 pincount:1
| anon flags: 0x3fffc00000b0004(uptodate|head|mappedtodisk|swapbacked|node=0|zone=0|lastcpupid=0xffff)
| raw: 03fffc0000000000 fffffc0000700001 ffffffff00700903 0000000100000000
| raw: 0000000000000200 0000000000000000 00000000ffffffff 0000000000000000
| head: 03fffc00000b0004 dead000000000100 dead000000000122 ffff00000a809dc1
| head: 0000000000020000 0000000000000000 00000000ffffffff 0000000000000000
| page dumped because: nonzero pincount
| CPU: 3 PID: 9 Comm: kworker/u8:0 Not tainted 6.3.0-rc2-00001-gc6811bf0cd87 #1
| Hardware name: linux,dummy-virt (DT)
| Workqueue: events_unbound io_ring_exit_work
| Call trace:
|  dump_backtrace+0x13c/0x208
|  show_stack+0x34/0x58
|  dump_stack_lvl+0x150/0x1a8
|  dump_stack+0x20/0x30
|  bad_page+0xec/0x238
|  free_tail_pages_check+0x280/0x350
|  free_pcp_prepare+0x60c/0x830
|  free_unref_page+0x50/0x498
|  free_compound_page+0xcc/0x100
|  free_transhuge_page+0x1f0/0x2b8
|  destroy_large_folio+0x80/0xc8
|  __folio_put+0xc4/0xf8
|  gup_put_folio+0xd0/0x250
|  unpin_user_page+0xcc/0x128
|  io_buffer_unmap+0xec/0x2c0
|  __io_sqe_buffers_unregister+0xa4/0x1e0
|  io_ring_exit_work+0x68c/0x1188
|  process_one_work+0x91c/0x1a58
|  worker_thread+0x48c/0xe30
|  kthread+0x278/0x2f0
|  ret_from_fork+0x10/0x20

Mark reports an issue with the recent patches coalescing compound pages
while registering them in io_uring. The reason is that we try to drop
excessive references with folio_put_refs(), but pages were acquired
with pin_user_pages(), which has extra accounting and so should be put
down with matching unpin_user_pages() or at least gup_put_folio().

As a fix unpin_user_pages() all but first page instead, and let's figure
out a better API after.

Fixes: 57bebf807e ("io_uring/rsrc: optimise registered huge pages")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/10efd5507d6d1f05ea0f3c601830e08767e189bd.1678980230.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-16 09:32:18 -06:00
Pavel Begunkov
5da28edd7b io_uring/msg_ring: let target know allocated index
msg_ring requests transferring files support auto index selection via
IORING_FILE_INDEX_ALLOC, however they don't return the selected index
to the target ring and there is no other good way for the userspace to
know where is the receieved file.

Return the index for allocated slots and 0 otherwise, which is
consistent with other fixed file installing requests.

Cc: stable@vger.kernel.org # v6.0+
Fixes: e6130eba8a ("io_uring: add support for passing fixed file descriptors")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://github.com/axboe/liburing/issues/809
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-16 07:16:56 -06:00
Li zeming
6acd352dfe io_uring: rsrc: Optimize return value variable 'ret'
The initialization assignment of the variable ret is changed to 0, only
in 'goto fail;' Use the ret variable as the function return value.

Signed-off-by: Li zeming <zeming@nfschina.com>
Link: https://lore.kernel.org/r/20230317182538.3027-1-zeming@nfschina.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-15 19:59:11 -06:00
Michal Koutný
a5fc1441af io_uring/sqpoll: Do not set PF_NO_SETAFFINITY on sqpoll threads
Users may specify a CPU where the sqpoll thread would run. This may
conflict with cpuset operations because of strict PF_NO_SETAFFINITY
requirement. That flag is unnecessary for polling "kernel" threads, see
the reasoning in commit 01e68ce08a ("io_uring/io-wq: stop setting
PF_NO_SETAFFINITY on io-wq workers"). Drop the flag on poll threads too.

Fixes: 01e68ce08a ("io_uring/io-wq: stop setting PF_NO_SETAFFINITY on io-wq workers")
Link: https://lore.kernel.org/all/20230314162559.pnyxdllzgw7jozgx@blackpad/
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Link: https://lore.kernel.org/r/20230314183332.25834-1-mkoutny@suse.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-15 06:50:59 -06:00
Jakub Kicinski
d0ddf5065f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Documentation/bpf/bpf_devel_QA.rst
  b7abcd9c65 ("bpf, doc: Link to submitting-patches.rst for general patch submission info")
  d56b0c461d ("bpf, docs: Fix link to netdev-FAQ target")
https://lore.kernel.org/all/20230307095812.236eb1be@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-09 22:22:11 -08:00
Jens Axboe
fa780334a8 io_uring: silence variable ‘prev’ set but not used warning
If io_uring.o is built with W=1, it triggers a warning:

io_uring/io_uring.c: In function ‘__io_submit_flush_completions’:
io_uring/io_uring.c:1502:40: warning: variable ‘prev’ set but not used [-Wunused-but-set-variable]
 1502 |         struct io_wq_work_node *node, *prev;
      |                                        ^~~~

which is due to the wq_list_for_each() iterator always keeping a 'prev'
variable. Most users need this to remove an entry from a list, for
example, but __io_submit_flush_completions() never does that.

Add a basic helper that doesn't track prev instead, and use that in
that function.

Reported-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-09 10:10:58 -07:00
Jens Axboe
03b3d6be73 io_uring/uring_cmd: ensure that device supports IOPOLL
It's possible for a file type to support uring commands, but not
pollable ones. Hence before issuing one of those, we should check
that it is supported and error out upfront if it isn't.

Cc: stable@vger.kernel.org
Fixes: 5756a3a7e7 ("io_uring: add iopoll infrastructure for io_uring_cmd")
Link: https://github.com/axboe/liburing/issues/816
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-09 09:23:59 -07:00
Jens Axboe
01e68ce08a io_uring/io-wq: stop setting PF_NO_SETAFFINITY on io-wq workers
Every now and then reports come in that are puzzled on why changing
affinity on the io-wq workers fails with EINVAL. This happens because they
set PF_NO_SETAFFINITY as part of their creation, as io-wq organizes
workers into groups based on what CPU they are running on.

However, this is purely an optimization and not a functional requirement.
We can allow setting affinity, and just lazily update our worker to wqe
mappings. If a given io-wq thread times out, it normally exits if there's
no more work to do. The exception is if it's the last worker available.
For the timeout case, check the affinity of the worker against group mask
and exit even if it's the last worker. New workers should be created with
the right mask and in the right location.

Reported-by:Daniel Dao <dqminh@cloudflare.com>
Link: https://lore.kernel.org/io-uring/CA+wXwBQwgxB3_UphSny-yAP5b26meeOu1W4TwYVcD_+5gOhvPw@mail.gmail.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-08 08:48:13 -07:00
Eric Dumazet
1036908045 net: reclaim skb->scm_io_uring bit
Commit 0091bfc817 ("io_uring/af_unix: defer registered
files gc to io_uring release") added one bit to struct sk_buff.

This structure is critical for networking, and we try very hard
to not add bloat on it, unless absolutely required.

For instance, we can use a specific destructor as a wrapper
around unix_destruct_scm(), to identify skbs that unix_gc()
has to special case.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-08 13:21:47 +00:00
Linus Torvalds
53ae7e1176 io_uring-6.3-2023-03-03
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Merge tag 'io_uring-6.3-2023-03-03' of git://git.kernel.dk/linux

Pull more io_uring updates from Jens Axboe:
 "Here's a set of fixes/changes that didn't make the first cut, either
  because they got queued before I sent the early merge request, or
  fixes that came in afterwards. In detail:

   - Don't set MSG_NOSIGNAL on recv/recvmsg opcodes, as AF_PACKET will
     error out (David)

   - Fix for spurious poll wakeups (me)

   - Fix for a file leak for buffered reads in certain conditions
     (Joseph)

   - Don't allow registered buffers of mixed types (Pavel)

   - Improve handling of huge pages for registered buffers (Pavel)

   - Provided buffer ring size calculation fix (Wojciech)

   - Minor cleanups (me)"

* tag 'io_uring-6.3-2023-03-03' of git://git.kernel.dk/linux:
  io_uring/poll: don't pass in wake func to io_init_poll_iocb()
  io_uring: fix fget leak when fs don't support nowait buffered read
  io_uring/poll: allow some retries for poll triggering spuriously
  io_uring: remove MSG_NOSIGNAL from recvmsg
  io_uring/rsrc: always initialize 'folio' to NULL
  io_uring/rsrc: optimise registered huge pages
  io_uring/rsrc: optimise single entry advance
  io_uring/rsrc: disallow multi-source reg buffers
  io_uring: remove unused wq_list_merge
  io_uring: fix size calculation when registering buf ring
  io_uring/rsrc: fix a comment in io_import_fixed()
  io_uring: rename 'in_idle' to 'in_cancel'
  io_uring: consolidate the put_ref-and-return section of adding work
2023-03-03 10:25:29 -08:00
Linus Torvalds
f122a08b19 capability: just use a 'u64' instead of a 'u32[2]' array
Back in 2008 we extended the capability bits from 32 to 64, and we did
it by extending the single 32-bit capability word from one word to an
array of two words.  It was then obfuscated by hiding the "2" behind two
macro expansions, with the reasoning being that maybe it gets extended
further some day.

That reasoning may have been valid at the time, but the last thing we
want to do is to extend the capability set any more.  And the array of
values not only causes source code oddities (with loops to deal with
it), but also results in worse code generation.  It's a lose-lose
situation.

So just change the 'u32[2]' into a 'u64' and be done with it.

We still have to deal with the fact that the user space interface is
designed around an array of these 32-bit values, but that was the case
before too, since the array layouts were different (ie user space
doesn't use an array of 32-bit values for individual capability masks,
but an array of 32-bit slices of multiple masks).

So that marshalling of data is actually simplified too, even if it does
remain somewhat obscure and odd.

This was all triggered by my reaction to the new "cap_isidentical()"
introduced recently.  By just using a saner data structure, it went from

	unsigned __capi;
	CAP_FOR_EACH_U32(__capi) {
		if (a.cap[__capi] != b.cap[__capi])
			return false;
	}
	return true;

to just being

	return a.val == b.val;

instead.  Which is rather more obvious both to humans and to compilers.

Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-03-01 10:01:22 -08:00
Jens Axboe
1947ddf9b3 io_uring/poll: don't pass in wake func to io_init_poll_iocb()
We only use one, and it's io_poll_wake(). Hardwire that in the initial
init, as well as in __io_queue_proc() if we're setting up for double
poll.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-01 10:06:53 -07:00
Joseph Qi
54aa7f2330 io_uring: fix fget leak when fs don't support nowait buffered read
Heming reported a BUG when using io_uring doing link-cp on ocfs2. [1]

Do the following steps can reproduce this BUG:
mount -t ocfs2 /dev/vdc /mnt/ocfs2
cp testfile /mnt/ocfs2/
./link-cp /mnt/ocfs2/testfile /mnt/ocfs2/testfile.1
umount /mnt/ocfs2

Then umount will fail, and it outputs:
umount: /mnt/ocfs2: target is busy.

While tracing umount, it blames mnt_get_count() not return as expected.
Do a deep investigation for fget()/fput() on related code flow, I've
finally found that fget() leaks since ocfs2 doesn't support nowait
buffered read.

io_issue_sqe
|-io_assign_file  // do fget() first
  |-io_read
  |-io_iter_do_read
    |-ocfs2_file_read_iter  // return -EOPNOTSUPP
  |-kiocb_done
    |-io_rw_done
      |-__io_complete_rw_common  // set REQ_F_REISSUE
    |-io_resubmit_prep
      |-io_req_prep_async  // override req->file, leak happens

This was introduced by commit a196c78b54 in v5.18. Fix it by don't
re-assign req->file if it has already been assigned.

[1] https://lore.kernel.org/ocfs2-devel/ab580a75-91c8-d68a-3455-40361be1bfa8@linux.alibaba.com/T/#t

Fixes: a196c78b54 ("io_uring: assign non-fixed early for async work")
Cc: <stable@vger.kernel.org>
Reported-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230228045459.13524-1-joseph.qi@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-28 05:58:42 -07:00
Jens Axboe
c16bda3759 io_uring/poll: allow some retries for poll triggering spuriously
If we get woken spuriously when polling and fail the operation with
-EAGAIN again, then we generally only allow polling again if data
had been transferred at some point. This is indicated with
REQ_F_PARTIAL_IO. However, if the spurious poll triggers when the socket
was originally empty, then we haven't transferred data yet and we will
fail the poll re-arm. This either punts the socket to io-wq if it's
blocking, or it fails the request with -EAGAIN if not. Neither condition
is desirable, as the former will slow things down, while the latter
will make the application confused.

We want to ensure that a repeated poll trigger doesn't lead to infinite
work making no progress, that's what the REQ_F_PARTIAL_IO check was
for. But it doesn't protect against a loop post the first receive, and
it's unnecessarily strict if we started out with an empty socket.

Add a somewhat random retry count, just to put an upper limit on the
potential number of retries that will be done. This should be high enough
that we won't really hit it in practice, unless something needs to be
aborted anyway.

Cc: stable@vger.kernel.org # v5.10+
Link: https://github.com/axboe/liburing/issues/364
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-25 20:10:13 -07:00
David Lamparter
7605c43d67 io_uring: remove MSG_NOSIGNAL from recvmsg
MSG_NOSIGNAL is not applicable for the receiving side, SIGPIPE is
generated when trying to write to a "broken pipe".  AF_PACKET's
packet_recvmsg() does enforce this, giving back EINVAL when MSG_NOSIGNAL
is set - making it unuseable in io_uring's recvmsg.

Remove MSG_NOSIGNAL from io_recvmsg_prep().

Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: David Lamparter <equinox@diac24.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230224150123.128346-1-equinox@diac24.net
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-24 12:59:02 -07:00
Jens Axboe
977bc87356 io_uring/rsrc: always initialize 'folio' to NULL
Smatch complains that:

smatch warnings:
io_uring/rsrc.c:1262 io_sqe_buffer_register() error: uninitialized symbol 'folio'.

'folio' may be used uninitialized, which can happen if we end up with a
single page mapped. Ensure that we clear folio to NULL at the top so
it's always set.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202302241432.YML1CD5C-lkp@intel.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-24 12:58:31 -07:00
Linus Torvalds
3822a7c409 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X bit.
 
 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.
 
 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes
 
 - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which
   does perform some memcg maintenance and cleanup work.
 
 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".  These filters provide users
   with finer-grained control over DAMOS's actions.  SeongJae has also done
   some DAMON cleanup work.
 
 - Kairui Song adds a series ("Clean up and fixes for swap").
 
 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".
 
 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series.  It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.
 
 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".
 
 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".
 
 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".
 
 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".
 
 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series "mm:
   support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap
   PTEs".
 
 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".
 
 - Sergey Senozhatsky has improved zsmalloc's memory utilization with his
   series "zsmalloc: make zspage chain size configurable".
 
 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.  The previous BPF-based approach had
   shortcomings.  See "mm: In-kernel support for memory-deny-write-execute
   (MDWE)".
 
 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
 
 - T.J.  Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".
 
 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a per-node
   basis.  See the series "Introduce per NUMA node memory error
   statistics".
 
 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage during
   compaction".
 
 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".
 
 - Christoph Hellwig has removed block_device_operations.rw_page() in ths
   series "remove ->rw_page".
 
 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".
 
 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier functions".
 
 - Some pagemap cleanup and generalization work in Mike Rapoport's series
   "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and
   "fixups for generic implementation of pfn_valid()"
 
 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
 
 - Jason Gunthorpe rationalized the GUP system's interface to the rest of
   the kernel in the series "Simplify the external interface for GUP".
 
 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface.  To support this, we'll temporarily be
   printing warnings when people use the debugfs interface.  See the series
   "mm/damon: deprecate DAMON debugfs interface".
 
 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.
 
 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".
 
 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".
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Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
   F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X
   bit.

 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.

 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes

 - Johannes Weiner has a series ("mm: push down lock_page_memcg()")
   which does perform some memcg maintenance and cleanup work.

 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".

   These filters provide users with finer-grained control over DAMOS's
   actions. SeongJae has also done some DAMON cleanup work.

 - Kairui Song adds a series ("Clean up and fixes for swap").

 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".

 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.

 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".

 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".

 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".

 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".

 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series
   "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
   swap PTEs".

 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".

 - Sergey Senozhatsky has improved zsmalloc's memory utilization with
   his series "zsmalloc: make zspage chain size configurable".

 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.

   The previous BPF-based approach had shortcomings. See "mm: In-kernel
   support for memory-deny-write-execute (MDWE)".

 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".

 - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".

 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a
   per-node basis. See the series "Introduce per NUMA node memory error
   statistics".

 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage
   during compaction".

 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".

 - Christoph Hellwig has removed block_device_operations.rw_page() in
   ths series "remove ->rw_page".

 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".

 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier
   functions".

 - Some pagemap cleanup and generalization work in Mike Rapoport's
   series "mm, arch: add generic implementation of pfn_valid() for
   FLATMEM" and "fixups for generic implementation of pfn_valid()"

 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".

 - Jason Gunthorpe rationalized the GUP system's interface to the rest
   of the kernel in the series "Simplify the external interface for
   GUP".

 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface. To support this, we'll temporarily be
   printing warnings when people use the debugfs interface. See the
   series "mm/damon: deprecate DAMON debugfs interface".

 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.

 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".

 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".

* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
  include/linux/migrate.h: remove unneeded externs
  mm/memory_hotplug: cleanup return value handing in do_migrate_range()
  mm/uffd: fix comment in handling pte markers
  mm: change to return bool for isolate_movable_page()
  mm: hugetlb: change to return bool for isolate_hugetlb()
  mm: change to return bool for isolate_lru_page()
  mm: change to return bool for folio_isolate_lru()
  objtool: add UACCESS exceptions for __tsan_volatile_read/write
  kmsan: disable ftrace in kmsan core code
  kasan: mark addr_has_metadata __always_inline
  mm: memcontrol: rename memcg_kmem_enabled()
  sh: initialize max_mapnr
  m68k/nommu: add missing definition of ARCH_PFN_OFFSET
  mm: percpu: fix incorrect size in pcpu_obj_full_size()
  maple_tree: reduce stack usage with gcc-9 and earlier
  mm: page_alloc: call panic() when memoryless node allocation fails
  mm: multi-gen LRU: avoid futile retries
  migrate_pages: move THP/hugetlb migration support check to simplify code
  migrate_pages: batch flushing TLB
  migrate_pages: share more code between _unmap and _move
  ...
2023-02-23 17:09:35 -08:00
Pavel Begunkov
57bebf807e io_uring/rsrc: optimise registered huge pages
When registering huge pages, internally io_uring will split them into
many PAGE_SIZE bvec entries. That's bad for performance as drivers need
to eventually dma-map the data and will do it individually for each bvec
entry. Coalesce huge pages into one large bvec.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22 09:57:24 -07:00
Pavel Begunkov
b000ae0ec2 io_uring/rsrc: optimise single entry advance
Iterating within the first bvec entry should be essentially free, but we
use iov_iter_advance() for that, which shows up in benchmark profiles
taking up to 0.5% of CPU. Replace it with a hand coded version.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22 09:57:23 -07:00
Pavel Begunkov
edd4782696 io_uring/rsrc: disallow multi-source reg buffers
If two or more mappings go back to back to each other they can be passed
into io_uring to be registered as a single registered buffer. That would
even work if mappings came from different sources, e.g. it's possible to
mix in this way anon pages and pages from shmem or hugetlb. That is not
a problem but it'd rather be less prone if we forbid such mixing.

Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22 09:57:23 -07:00
Pavel Begunkov
9a1563d172 io_uring: remove unused wq_list_merge
There are no users of wq_list_merge, kill it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5f9ad0301949213230ad9000a8359d591aae615a.1677002255.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22 09:57:23 -07:00
Wojciech Lukowicz
48ba08374e io_uring: fix size calculation when registering buf ring
Using struct_size() to calculate the size of io_uring_buf_ring will sum
the size of the struct and of the bufs array. However, the struct's fields
are overlaid with the array making the calculated size larger than it
should be.

When registering a ring with N * PAGE_SIZE / sizeof(struct io_uring_buf)
entries, i.e. with fully filled pages, the calculated size will span one
more page than it should and io_uring will try to pin the following page.
Depending on how the application allocated the ring, it might succeed
using an unrelated page or fail returning EFAULT.

The size of the ring should be the product of ring_entries and the size
of io_uring_buf, i.e. the size of the bufs array only.

Fixes: c7fb19428d ("io_uring: add support for ring mapped supplied buffers")
Signed-off-by: Wojciech Lukowicz <wlukowicz01@gmail.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230218184141.70891-1-wlukowicz01@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22 09:57:23 -07:00
Pavel Begunkov
6bf65a1b36 io_uring/rsrc: fix a comment in io_import_fixed()
io_import_fixed() supports offsets, but "may not" means the opposite.
Replace it with "might not" so the comments rather speaks about
possible cases.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/5b5f79958456caa6dc532f6205f75f224b232c81.1676902343.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22 09:57:23 -07:00
Jens Axboe
8d664282a0 io_uring: rename 'in_idle' to 'in_cancel'
This better describes what it does - it's incremented when the task is
currently undergoing a cancelation operation, due to exiting or exec'ing.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22 09:57:23 -07:00
Jens Axboe
ce8e04f6e5 io_uring: consolidate the put_ref-and-return section of adding work
We've got a few cases of this, move them to one section and just use
gotos to get there. Reduces the text section on both arm64 and x86-64,
using gcc-12.2.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22 09:57:23 -07:00
Linus Torvalds
5b0ed59649 for-6.3/block-2023-02-16
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Merge tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe updates via Christoph:
      - Small improvements to the logging functionality (Amit Engel)
      - Authentication cleanups (Hannes Reinecke)
      - Cleanup and optimize the DMA mapping cod in the PCIe driver
        (Keith Busch)
      - Work around the command effects for Format NVM (Keith Busch)
      - Misc cleanups (Keith Busch, Christoph Hellwig)
      - Fix and cleanup freeing single sgl (Keith Busch)

 - MD updates via Song:
      - Fix a rare crash during the takeover process
      - Don't update recovery_cp when curr_resync is ACTIVE
      - Free writes_pending in md_stop
      - Change active_io to percpu

 - Updates to drbd, inching us closer to unifying the out-of-tree driver
   with the in-tree one (Andreas, Christoph, Lars, Robert)

 - BFQ update adding support for multi-actuator drives (Paolo, Federico,
   Davide)

 - Make brd compliant with REQ_NOWAIT (me)

 - Fix for IOPOLL and queue entering, fixing stalled IO waiting on
   timeouts (me)

 - Fix for REQ_NOWAIT with multiple bios (me)

 - Fix memory leak in blktrace cleanup (Greg)

 - Clean up sbitmap and fix a potential hang (Kemeng)

 - Clean up some bits in BFQ, and fix a bug in the request injection
   (Kemeng)

 - Clean up the request allocation and issue code, and fix some bugs
   related to that (Kemeng)

 - ublk updates and fixes:
      - Add support for unprivileged ublk (Ming)
      - Improve device deletion handling (Ming)
      - Misc (Liu, Ziyang)

 - s390 dasd fixes (Alexander, Qiheng)

 - Improve utility of request caching and fixes (Anuj, Xiao)

 - zoned cleanups (Pankaj)

 - More constification for kobjs (Thomas)

 - blk-iocost cleanups (Yu)

 - Remove bio splitting from drivers that don't need it (Christoph)

 - Switch blk-cgroups to use struct gendisk. Some of this is now
   incomplete as select late reverts were done. (Christoph)

 - Add bvec initialization helpers, and convert callers to use that
   rather than open-coding it (Christoph)

 - Misc fixes and cleanups (Jinke, Keith, Arnd, Bart, Li, Martin,
   Matthew, Ulf, Zhong)

* tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux: (169 commits)
  brd: use radix_tree_maybe_preload instead of radix_tree_preload
  block: use proper return value from bio_failfast()
  block: bio-integrity: Copy flags when bio_integrity_payload is cloned
  block: Fix io statistics for cgroup in throttle path
  brd: mark as nowait compatible
  brd: check for REQ_NOWAIT and set correct page allocation mask
  brd: return 0/-error from brd_insert_page()
  block: sync mixed merged request's failfast with 1st bio's
  Revert "blk-cgroup: pin the gendisk in struct blkcg_gq"
  Revert "blk-cgroup: pass a gendisk to blkg_lookup"
  Revert "blk-cgroup: delay blk-cgroup initialization until add_disk"
  Revert "blk-cgroup: delay calling blkcg_exit_disk until disk_release"
  Revert "blk-cgroup: move the cgroup information to struct gendisk"
  nvme-pci: remove iod use_sgls
  nvme-pci: fix freeing single sgl
  block: ublk: check IO buffer based on flag need_get_data
  s390/dasd: Fix potential memleak in dasd_eckd_init()
  s390/dasd: sort out physical vs virtual pointers usage
  block: Remove the ALLOC_CACHE_SLACK constant
  block: make kobj_type structures constant
  ...
2023-02-20 14:27:21 -08:00
Linus Torvalds
c1ef500307 for-6.3/iter-ubuf-2023-02-16
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Merge tag 'for-6.3/iter-ubuf-2023-02-16' of git://git.kernel.dk/linux

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

* tag 'for-6.3/iter-ubuf-2023-02-16' of git://git.kernel.dk/linux:
  block: use iter_ubuf for single range
  iov_iter: move iter_ubuf check inside restore WARN
  io_uring: use iter_ubuf for single range imports
  io_uring: switch network send/recv to ITER_UBUF
  iov: add import_ubuf()
2023-02-20 14:03:57 -08:00
Josh Triplett
7d3fd88d61 io_uring: Support calling io_uring_register with a registered ring fd
Add a new flag IORING_REGISTER_USE_REGISTERED_RING (set via the high bit
of the opcode) to treat the fd as a registered index rather than a file
descriptor.

This makes it possible for a library to open an io_uring, register the
ring fd, close the ring fd, and subsequently use the ring entirely via
registered index.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Link: https://lore.kernel.org/r/f2396369e638284586b069dbddffb8c992afba95.1676419314.git.josh@joshtriplett.org
[axboe: remove extra high bit clear]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-16 06:09:30 -07:00
Richard Guy Briggs
fbe870a72f io_uring,audit: don't log IORING_OP_MADVISE
fadvise and madvise both provide hints for caching or access pattern for
file and memory respectively.  Skip them.

Fixes: 5bd2182d58 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Link: https://lore.kernel.org/r/b5dfdcd541115c86dbc774aa9dd502c964849c5f.1675282642.git.rgb@redhat.com
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-10 16:00:30 -07:00
Jens Axboe
2f2bb1ffc9 io_uring: mark task TASK_RUNNING before handling resume/task work
Just like for task_work, set the task mode to TASK_RUNNING before doing
any potential resume work. We're not holding any locks at this point,
but we may have already set the task state to TASK_INTERRUPTIBLE in
preparation for going to sleep waiting for events. Ensure that we set it
back to TASK_RUNNING if we have work to process, to avoid warnings on
calling blocking operations with !TASK_RUNNING.

Fixes: b5d3ae202f ("io_uring: handle TIF_NOTIFY_RESUME when checking for task_work")
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/oe-lkp/202302062208.24d3e563-oliver.sang@intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-06 08:23:21 -07:00
Christoph Hellwig
cc342a2193 io_uring: use bvec_set_page to initialize a bvec
Use the bvec_set_page helper to initialize a bvec.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230203150634.3199647-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-03 10:17:42 -07:00
Dylan Yudaken
0ffae640ad io_uring: always go async for unsupported open flags
No point in issuing -> return -EAGAIN -> go async, when it can be done upfront.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20230127135227.3646353-5-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:26 -07:00
Dylan Yudaken
c31cc60fdd io_uring: always go async for unsupported fadvise flags
No point in issuing -> return -EAGAIN -> go async, when it can be done upfront.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20230127135227.3646353-4-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:26 -07:00
Dylan Yudaken
aebb224fd4 io_uring: for requests that require async, force it
Some requests require being run async as they do not support
non-blocking. Instead of trying to issue these requests, getting -EAGAIN
and then queueing them for async issue, rather just force async upfront.

Add WARN_ON_ONCE to make sure surprising code paths do not come up,
however in those cases the bug would end up being a blocking
io_uring_enter(2) which should not be critical.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20230127135227.3646353-3-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:26 -07:00
Dylan Yudaken
6bb3085556 io_uring: if a linked request has REQ_F_FORCE_ASYNC then run it async
REQ_F_FORCE_ASYNC was being ignored for re-queueing linked
requests. Instead obey that flag.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20230127135227.3646353-2-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:26 -07:00
Jens Axboe
f586800854 io_uring: add reschedule point to handle_tw_list()
If CONFIG_PREEMPT_NONE is set and the task_work chains are long, we
could be running into issues blocking others for too long. Add a
reschedule check in handle_tw_list(), and flush the ctx if we need to
reschedule.

Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Jens Axboe
fcc926bb85 io_uring: add a conditional reschedule to the IOPOLL cancelation loop
If the kernel is configured with CONFIG_PREEMPT_NONE, we could be
sitting in a tight loop reaping events but not giving them a chance to
finish. This results in a trace ala:

rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 	2-...!: (5249 ticks this GP) idle=935c/1/0x4000000000000000 softirq=4265/4274 fqs=1
	(t=5251 jiffies g=465 q=4135 ncpus=4)
rcu: rcu_sched kthread starved for 5249 jiffies! g465 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_sched       state:R  running task     stack:0     pid:12    ppid:2      flags:0x00000008
Call trace:
 __switch_to+0xb0/0xc8
 __schedule+0x43c/0x520
 schedule+0x4c/0x98
 schedule_timeout+0xbc/0xdc
 rcu_gp_fqs_loop+0x308/0x344
 rcu_gp_kthread+0xd8/0xf0
 kthread+0xb8/0xc8
 ret_from_fork+0x10/0x20
rcu: Stack dump where RCU GP kthread last ran:
Task dump for CPU 0:
task:kworker/u8:10   state:R  running task     stack:0     pid:89    ppid:2      flags:0x0000000a
Workqueue: events_unbound io_ring_exit_work
Call trace:
 __switch_to+0xb0/0xc8
 0xffff0000c8fefd28
CPU: 2 PID: 95 Comm: kworker/u8:13 Not tainted 6.2.0-rc5-00042-g40316e337c80-dirty #2759
Hardware name: linux,dummy-virt (DT)
Workqueue: events_unbound io_ring_exit_work
pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : io_do_iopoll+0x344/0x360
lr : io_do_iopoll+0xb8/0x360
sp : ffff800009bebc60
x29: ffff800009bebc60 x28: 0000000000000000 x27: 0000000000000000
x26: ffff0000c0f67d48 x25: ffff0000c0f67840 x24: ffff800008950024
x23: 0000000000000001 x22: 0000000000000000 x21: ffff0000c27d3200
x20: ffff0000c0f67840 x19: ffff0000c0f67800 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000001 x13: 0000000000000001 x12: 0000000000000000
x11: 0000000000000179 x10: 0000000000000870 x9 : ffff800009bebd60
x8 : ffff0000c27d3ad0 x7 : fefefefefefefeff x6 : 0000646e756f626e
x5 : ffff0000c0f67840 x4 : 0000000000000000 x3 : ffff0000c2398000
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 io_do_iopoll+0x344/0x360
 io_uring_try_cancel_requests+0x21c/0x334
 io_ring_exit_work+0x90/0x40c
 process_one_work+0x1a4/0x254
 worker_thread+0x1ec/0x258
 kthread+0xb8/0xc8
 ret_from_fork+0x10/0x20

Add a cond_resched() in the cancelation IOPOLL loop to fix this.

Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
50470fc572 io_uring: return normal tw run linking optimisation
io_submit_flush_completions() may produce new task_work items, so it's a
good idea to recheck the task_work list after flushing completions. The
optimisation is not new and was accidentially removed by
f88262e60b ("io_uring: lockless task list")

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a7ed5ede84de190832cc33ebbcdd6e91cd90f5b6.1674484266.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
cb6bf7f285 io_uring: refactor tctx_task_work
Merge almost identical sections of tctx_task_work(), this will make code
modifications later easier and also inlines handle_tw_list().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d06592d91e3e7559e7a4dbb8907d110863008dc7.1674484266.git.asml.silence@gmail.com
[axboe: fold in setting count to zero patch from Tom Rix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
5afa465071 io_uring: refactor io_put_task helpers
Add a helper for putting refs from the target task context, rename
__io_put_task() and add a couple of comments around. Use the remote
version for __io_req_complete_post(), the local is only needed for
__io_submit_flush_completions().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3bf92ebd594769d8a5d648472a8e335f2031d542.1674484266.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
c8576f3e61 io_uring: refactor req allocation
Follow the io_get_sqe pattern returning the result via a pointer
and hide request cache refill inside io_alloc_req().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8c37c2e8a3cb5e4cd6a8ae3b91371227a92708a6.1674484266.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
b5083dfa36 io_uring: improve io_get_sqe
Return an SQE from io_get_sqe() as a parameter and use the return value
to determine if it failed or not. This enables the compiler to compile out
the sqe NULL check when we know that the return SQE is valid.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9cceb11329240ea097dffef6bf0a675bca14cf42.1674484266.git.asml.silence@gmail.com
[axboe: remove bogus const modifier on return value]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
b2aa66aff6 io_uring: kill outdated comment about overflow flush
__io_cqring_overflow_flush() doesn't return anything anymore, remove
outdate comment.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4ce2bcbb17eac80cdf883fd1459d5ee6586e238c.1674484266.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
c10bb64684 io_uring: use user visible tail in io_uring_poll()
We return POLLIN from io_uring_poll() depending on whether there are
CQEs for the userspace, and so we should use the user visible tail
pointer instead of a transient cached value.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/228ffcbf30ba98856f66ffdb9a6a60ead1dd96c0.1674484266.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Jens Axboe
f499254474 io_uring: pass in io_issue_def to io_assign_file()
This generates better code for me, avoiding an extra load on arm64, and
both call sites already have this variable available for easy passing.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Breno Leitao
c1755c25a7 io_uring: Enable KASAN for request cache
Every io_uring request is represented by struct io_kiocb, which is
cached locally by io_uring (not SLAB/SLUB) in the list called
submit_state.freelist. This patch simply enabled KASAN for this free
list.

This list is initially created by KMEM_CACHE, but later, managed by
io_uring. This patch basically poisons the objects that are not used
(i.e., they are the free list), and unpoisons it when the object is
allocated/removed from the list.

Touching these poisoned objects while in the freelist will cause a KASAN
warning.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Jens Axboe
b5d3ae202f io_uring: handle TIF_NOTIFY_RESUME when checking for task_work
If TIF_NOTIFY_RESUME is set, then we need to call resume_user_mode_work()
for PF_IO_WORKER threads. They never return to usermode, hence never get
a chance to process any items that are marked by this flag. Most notably
this includes the final put of files, but also any throttling markers set
by block cgroups.

Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Jens Axboe
8572df941c io_uring/msg-ring: ensure flags passing works for task_work completions
If the target ring is using IORING_SETUP_SINGLE_ISSUER and we're posting
a message from a different thread, then we need to ensure that the
fallback task_work that posts the CQE knwos about the flags passing as
well. If not we'll always be posting 0 as the flags.

Fixes: 3563d7ed58a5 ("io_uring/msg_ring: Pass custom flags to the cqe")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Breno Leitao
f30bd4d038 io_uring: Split io_issue_def struct
This patch removes some "cold" fields from `struct io_issue_def`.

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

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

This is the size for the structs:

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

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

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

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

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20230112144411.2624698-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
68a2cc1bba io_uring: refactor __io_req_complete_post
Keep parts of __io_req_complete_post() relying on req->flags together so
the value can be cached.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2b4fbb42f404a0e75c4d9f0a5b16f314a839d0a9.1673887636.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
31f084b7b0 io_uring: simplify fallback execution
Lock the ring with uring_lock in io_fallback_req_func(), which should
make it a bit safer and easier. With that we also don't need refs
pinning as io_ring_exit_work() will wait until uring_lock is freed.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/56170e6a0cbfc8edee2794c6613e8f6f1d76d276.1673887636.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
89800a2dd5 io_uring: don't export io_put_task()
io_put_task() is only used in uring.c so enclose it there together with
__io_put_task().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/43c7f9227e2ab215f1a6069dadbc5382bed346fe.1673887636.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
b0b7a7d24b io_uring: return back links tw run optimisation
io_submit_flush_completions() may queue new requests for tw execution,
especially true for linked requests. Recheck the tw list for emptiness
after flushing completions.

Note that this doesn't really fix the commit referenced below, but it
does reinstate an optimization that existed before that got merged.

Fixes: f88262e60b ("io_uring: lockless task list")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6328acdbb5e60efc762b18003382de077e6e1367.1673887636.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Quanfa Fu
88b80534f6 io_uring: make io_sqpoll_wait_sq return void
Change the return type to void since it always return 0, and no need
to do the checking in syscall io_uring_enter.

Signed-off-by: Quanfa Fu <quanfafu@gmail.com>
Link: https://lore.kernel.org/r/20230115071519.554282-1-quanfafu@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
c3f4d39ee4 io_uring: optimise deferred tw execution
We needed fake nodes in __io_run_local_work() and to avoid unecessary wake
ups while the task already running task_works, but we don't need them
anymore since wake ups are protected by cq_waiting, which is always
cleared by the time we're executing deferred task_work items.

Note that because of loose sync around cq_waiting clearing
io_req_local_work_add() may wake the task more than once, but that's
fine and should be rare to not hurt perf.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8839534891f0a2f1076e78554a31ea7e099f7de5.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
d80c0f00d0 io_uring: add io_req_local_work_add wake fast path
Don't wake the master task after queueing a deferred tw unless it's
currently waiting in io_cqring_wait.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/717702d772825a6647e6c315b4690277ba84c3fc.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
130bd686d9 io_uring: waitqueue-less cq waiting
With DEFER_TASKRUN only ctx->submitter_task might be waiting for CQEs,
we can use this to optimise io_cqring_wait(). Replace ->cq_wait
waitqueue with waking the task directly.

It works but misses an important optimisation covered by the following
patch, so this patch without follow ups might hurt performance.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/103d174d35d919d4cb0922d8a9c93a8f0c35f74a.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
3181e22fb7 io_uring: wake up optimisations
Flush completions is done either from the submit syscall or by the
task_work, both are in the context of the submitter task, and when it
goes for a single threaded rings like implied by ->task_complete, there
won't be any waiters on ->cq_wait but the master task. That means that
there can be no tasks sleeping on cq_wait while we run
__io_submit_flush_completions() and so waking up can be skipped.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/60ad9768ec74435a0ddaa6eec0ffa7729474f69f.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
bca39f3905 io_uring: add lazy poll_wq activation
Even though io_poll_wq_wake()'s waitqueue_active reuses a barrier we do
for another waitqueue, it's not going to be the case in the future and
so we want to have a fast path for it when the ring has never been
polled.

Move poll_wq wake ups into __io_commit_cqring_flush() using a new flag
called ->poll_activated. The idea behind the flag is to set it when the
ring was polled for the first time. This requires additional sync to not
miss events, which is done here by using task_work for ->task_complete
rings, and by default enabling the flag for all other types of rings.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/060785e8e9137a920b232c0c7f575b131af19cac.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
7b235dd82a io_uring: separate wq for ring polling
Don't use ->cq_wait for ring polling but add a separate wait queue for
it. We need it for following patches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dea0be0bf990503443c5c6c337fc66824af7d590.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
360173ab9e io_uring: move io_run_local_work_locked
io_run_local_work_locked() is only used in io_uring.c, move it there.
With that we can also make __io_run_local_work() static.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/91757bcb33e5774e49fed6f2b6e058630608119b.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
3e5655552a io_uring: mark io_run_local_work static
io_run_local_work is enclosed in io_uring.c, we don't need to export it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b477fb81f5e77044f724a06fe245d5c078659364.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
2f413956cc io_uring: don't set TASK_RUNNING in local tw runner
The CQ waiting loop sets TASK_RUNNING before trying to execute
task_work, no need to repeat it in io_run_local_work().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9d9422c429ef3f9457b4f4b8288bf4789564f33b.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
bd550173ac io_uring: refactor io_wake_function
Remove a local variable ctx in io_wake_function(), we don't need it if
io_should_wake() triggers it to wake up.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e60eb1008aebe286aab7d34c772ed01c447bddb1.1673274244.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Dmitrii Bundin
81594e7e7a io_uring: remove excessive unlikely on IS_ERR
The IS_ERR function uses the IS_ERR_VALUE macro under the hood which
already wraps the condition into unlikely.

Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
Link: https://lore.kernel.org/r/20230109185854.25698-1-dmitrii.bundin.a@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Breno Leitao
cbeb47a7b5 io_uring/msg_ring: Pass custom flags to the cqe
This patch adds a new flag (IORING_MSG_RING_FLAGS_PASS) in the message
ring operations (IORING_OP_MSG_RING). This new flag enables the sender
to specify custom flags, which will be copied over to cqe->flags in the
receiving ring.  These custom flags should be specified using the
sqe->file_index field.

This mechanism provides additional flexibility when sending messages
between rings.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230103160507.617416-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
d33a39e577 io_uring: keep timeout in io_wait_queue
Move waiting timeout into io_wait_queue

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e4b48a9e26a3b1cf97c80121e62d4b5ab873d28d.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
46ae7eef44 io_uring: optimise non-timeout waiting
Unlike the jiffy scheduling version, schedule_hrtimeout() jumps a few
functions before getting into schedule() even if there is no actual
timeout needed. Some tests showed that it takes up to 1% of CPU cycles.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/89f880574eceee6f4899783377ead234df7b3d04.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
326a9e482e io_uring: set TASK_RUNNING right after schedule
Instead of constantly watching that the state of the task is running
before executing tw or taking locks in io_cqring_wait(), switch it back
to TASK_RUNNING immediately.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/246dddee247d89fd52023f785ed17cc34962a008.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
490c00eb4f io_uring: simplify io_has_work
->work_llist should never be non-empty for a non DEFER_TASKRUN ring, so
we can safely skip checking the flag.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/26af9f73c09a56c9a035f94db56127358688f3aa.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
846072f16e io_uring: mimimise io_cqring_wait_schedule
io_cqring_wait_schedule() is called after we started waiting on the cq
wq and set the state to TASK_INTERRUPTIBLE, for that reason we have to
constantly worry whether we has returned the state back to running or
not. Leave only quick checks in io_cqring_wait_schedule() and move the
rest including running task work to the callers. Note, we run tw in the
loop after the sched checks because of the fast path in the beginning of
the function.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2814fabe75e2e019e7ca43ea07daa94564349805.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Pavel Begunkov
3fcf19d592 io_uring: parse check_cq out of wq waiting
We already avoid flushing overflows in io_cqring_wait_schedule() but
only return an error for the outer loop to handle it. Minimise it even
further by moving all ->check_cq parsing there.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9dfcec3121013f98208dbf79368d636d74e1231a.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:39 -07:00
Pavel Begunkov
140102ae9a io_uring: move defer tw task checks
Most places that want to run local tw explicitly and in advance check if
they are allowed to do so. Don't rely on a similar check in
__io_run_local_work(), leave it as a just-in-case warning and make sure
callers checks capabilities themselves.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/990fe0e8e70fd4d57e43625e5ce8fba584821d1a.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:39 -07:00
Pavel Begunkov
1414d62985 io_uring: kill io_run_task_work_ctx
There is only one user of io_run_task_work_ctx(), inline it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/40953c65f7c88fb00cdc4d870ca5d5319fb3d7ea.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:39 -07:00
Pavel Begunkov
f36ba6cf1a io_uring: don't iterate cq wait fast path
Task work runners keep running until all queues tw items are exhausted.
It's also rare for defer tw to queue normal tw and vise versa. Taking it
into account, there is only a dim chance that further iterating the
io_cqring_wait() fast path will get us anything and so we can remove
the loop there.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1f9565726661266abaa5d921e97433c831759ecf.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:39 -07:00
Pavel Begunkov
0c4fe008c9 io_uring: rearrange defer list checks
There should be nothing in the ->work_llist for non DEFER_TASKRUN rings,
so we can skip flag checks and test the list emptiness directly. Also
move it out of io_run_local_work() for inlining.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/331d63fd15ca79b35b95c82a82d9246110686392.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:39 -07:00
Dylan Yudaken
ef5c600adb io_uring: always prep_async for drain requests
Drain requests all go through io_drain_req, which has a quick exit in case
there is nothing pending (ie the drain is not useful). In that case it can
run the issue the request immediately.

However for safety it queues it through task work.
The problem is that in this case the request is run asynchronously, but
the async work has not been prepared through io_req_prep_async.

This has not been a problem up to now, as the task work always would run
before returning to userspace, and so the user would not have a chance to
race with it.

However - with IORING_SETUP_DEFER_TASKRUN - this is no longer the case and
the work might be defered, giving userspace a chance to change data being
referred to in the request.

Instead _always_ prep_async for drain requests, which is simpler anyway
and removes this issue.

Cc: stable@vger.kernel.org
Fixes: c0e0d6ba25 ("io_uring: add IORING_SETUP_DEFER_TASKRUN")
Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20230127105911.2420061-1-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-27 06:29:29 -07:00
Jens Axboe
b00c51ef8f io_uring/net: cache provided buffer group value for multishot receives
If we're using ring provided buffers with multishot receive, and we end
up doing an io-wq based issue at some points that also needs to select
a buffer, we'll lose the initially assigned buffer group as
io_ring_buffer_select() correctly clears the buffer group list as the
issue isn't serialized by the ctx uring_lock. This is fine for normal
receives as the request puts the buffer and finishes, but for multishot,
we will re-arm and do further receives. On the next trigger for this
multishot receive, the receive will try and pick from a buffer group
whose value is the same as the buffer ID of the las receive. That is
obviously incorrect, and will result in a premature -ENOUFS error for
the receive even if we had available buffers in the correct group.

Cache the buffer group value at prep time, so we can restore it for
future receives. This only needs doing for the above mentioned case, but
just do it by default to keep it easier to read.

Cc: stable@vger.kernel.org
Fixes: b3fdea6ecb ("io_uring: multishot recv")
Fixes: 9bb66906f2 ("io_uring: support multishot in recvmsg")
Cc: Dylan Yudaken <dylany@meta.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-23 07:08:08 -07:00
Jens Axboe
8caa03f10b io_uring/poll: don't reissue in case of poll race on multishot request
A previous commit fixed a poll race that can occur, but it's only
applicable for multishot requests. For a multishot request, we can safely
ignore a spurious wakeup, as we never leave the waitqueue to begin with.

A blunt reissue of a multishot armed request can cause us to leak a
buffer, if they are ring provided. While this seems like a bug in itself,
it's not really defined behavior to reissue a multishot request directly.
It's less efficient to do so as well, and not required to rearm anything
like it is for singleshot poll requests.

Cc: stable@vger.kernel.org
Fixes: 6e5aedb932 ("io_uring/poll: attempt request issue after racy poll wakeup")
Reported-and-tested-by: Olivier Langlois <olivier@trillion01.com>
Link: https://github.com/axboe/liburing/issues/778
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-20 15:11:54 -07:00
Pavel Begunkov
8579538c89 io_uring/msg_ring: fix remote queue to disabled ring
IORING_SETUP_R_DISABLED rings don't have the submitter task set, so
it's not always safe to use ->submitter_task. Disallow posting msg_ring
messaged to disabled rings. Also add task NULL check for loosy sync
around testing for IORING_SETUP_R_DISABLED.

Cc: stable@vger.kernel.org
Fixes: 6d043ee116 ("io_uring: do msg_ring in target task via tw")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-20 09:49:34 -07:00
Pavel Begunkov
56d8e3180c io_uring/msg_ring: fix flagging remote execution
There is a couple of problems with queueing a tw in io_msg_ring_data()
for remote execution. First, once we queue it the target ring can
go away and so setting IORING_SQ_TASKRUN there is not safe. Secondly,
the userspace might not expect IORING_SQ_TASKRUN.

Extract a helper and uniformly use TWA_SIGNAL without TWA_SIGNAL_NO_IPI
tricks for now, just as it was done in the original patch.

Cc: stable@vger.kernel.org
Fixes: 6d043ee116 ("io_uring: do msg_ring in target task via tw")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-20 09:49:29 -07:00
Jens Axboe
e12d7a46f6 io_uring/msg_ring: fix missing lock on overflow for IOPOLL
If the target ring is configured with IOPOLL, then we always need to hold
the target ring uring_lock before posting CQEs. We could just grab it
unconditionally, but since we don't expect many target rings to be of this
type, make grabbing the uring_lock conditional on the ring type.

Link: https://lore.kernel.org/io-uring/Y8krlYa52%2F0YGqkg@ip-172-31-85-199.ec2.internal/
Reported-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-19 10:43:59 -07:00
Jens Axboe
423d5081d0 io_uring/msg_ring: move double lock/unlock helpers higher up
In preparation for needing them somewhere else, move them and get rid of
the unused 'issue_flags' for the unlock side.

No functional changes in this patch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-19 09:01:27 -07:00
David Hildenbrand
fc4f4be9b5 mm/nommu: factor out check for NOMMU shared mappings into is_nommu_shared_mapping()
Patch series "mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings".

Trying to reduce the confusion around VM_SHARED and VM_MAYSHARE first
requires !CONFIG_MMU to stop using VM_MAYSHARE for MAP_PRIVATE mappings. 
CONFIG_MMU only sets VM_MAYSHARE for MAP_SHARED mappings.

This paves the way for further VM_MAYSHARE and VM_SHARED cleanups: for
example, renaming VM_MAYSHARED to VM_MAP_SHARED to make it cleaner what is
actually means.

Let's first get the weird case out of the way and not use VM_MAYSHARE in
MAP_PRIVATE mappings, using a new VM_MAYOVERLAY flag instead.


This patch (of 3):

We want to stop using VM_MAYSHARE in private mappings to pave the way for
clarifying the semantics of VM_MAYSHARE vs.  VM_SHARED and reduce the
confusion.  While CONFIG_MMU uses VM_MAYSHARE to represent MAP_SHARED,
!CONFIG_MMU also sets VM_MAYSHARE for selected R/O private file mappings
that are an effective overlay of a file mapping.

Let's factor out all relevant VM_MAYSHARE checks in !CONFIG_MMU code into
is_nommu_shared_mapping() first.

Note that whenever VM_SHARED is set, VM_MAYSHARE must be set as well
(unless there is a serious BUG).  So there is not need to test for
VM_SHARED manually.

No functional change intended.

Link: https://lkml.kernel.org/r/20230102160856.500584-1-david@redhat.com
Link: https://lkml.kernel.org/r/20230102160856.500584-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:56 -08:00
Pavel Begunkov
544d163d65 io_uring: lock overflowing for IOPOLL
syzbot reports an issue with overflow filling for IOPOLL:

WARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734
CPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0
Workqueue: events_unbound io_ring_exit_work
Call trace:
 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734
 io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773
 io_fill_cqe_req io_uring/io_uring.h:168 [inline]
 io_do_iopoll+0x474/0x62c io_uring/rw.c:1065
 io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513
 io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056
 io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869
 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289
 worker_thread+0x340/0x610 kernel/workqueue.c:2436
 kthread+0x12c/0x158 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863

There is no real problem for normal IOPOLL as flush is also called with
uring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL,
for which __io_cqring_overflow_flush() happens from the CQ waiting path.

Reported-and-tested-by: syzbot+6805087452d72929404e@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-13 07:32:46 -07:00
Jens Axboe
6e5aedb932 io_uring/poll: attempt request issue after racy poll wakeup
If we have multiple requests waiting on the same target poll waitqueue,
then it's quite possible to get a request triggered and get disappointed
in not being able to make any progress with it. If we race in doing so,
we'll potentially leave the poll request on the internal tables, but
removed from the waitqueue. That means that any subsequent trigger of
the poll waitqueue will not kick that request into action, causing an
application to potentially wait for completion of a request that will
never happen.

Fix this by adding a new poll return state, IOU_POLL_REISSUE. Rather
than have complicated logic for how to re-arm a given type of request,
just punt it for a reissue.

While in there, move the 'ret' variable to the only section where it
gets used. This avoids confusion the scope of it.

Cc: stable@vger.kernel.org
Fixes: eb0089d629 ("io_uring: single shot poll removal optimisation")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-12 10:35:51 -07:00
Jens Axboe
ea97cbebaf io_uring/fdinfo: include locked hash table in fdinfo output
A previous commit split the hash table for polled requests into two
parts, but didn't get the fdinfo output updated. This means that it's
less useful for debugging, as we may think a given request is not pending
poll.

Fix this up by dumping the locked hash table contents too.

Fixes: 9ca9fb24d5 ("io_uring: mutex locked poll hashing")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-10 10:24:52 -07:00
Jens Axboe
febb985c06 io_uring/poll: add hash if ready poll request can't complete inline
If we don't, then we may lose access to it completely, leading to a
request leak. This will eventually stall the ring exit process as
well.

Cc: stable@vger.kernel.org
Fixes: 49f1c68e04 ("io_uring: optimise submission side poll_refs")
Reported-and-tested-by: syzbot+6c95df01470a47fc3af4@syzkaller.appspotmail.com
Link: https://lore.kernel.org/io-uring/0000000000009f829805f1ce87b2@google.com/
Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-09 15:46:57 -07:00
Jens Axboe
1e23db450c io_uring: use iter_ubuf for single range imports
This is more efficient than iter_iov.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
[merge to 6.2, minor fixes]
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-01-08 20:59:17 -07:00
Jens Axboe
4b61152e10 io_uring: switch network send/recv to ITER_UBUF
This is more efficient than iter_iov.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
[merged to 6.2]
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-01-08 20:59:17 -07:00
Jens Axboe
e6db6f9398 io_uring/io-wq: only free worker if it was allocated for creation
We have two types of task_work based creation, one is using an existing
worker to setup a new one (eg when going to sleep and we have no free
workers), and the other is allocating a new worker. Only the latter
should be freed when we cancel task_work creation for a new worker.

Fixes: af82425c6a ("io_uring/io-wq: free worker if task_work creation is canceled")
Reported-by: syzbot+d56ec896af3637bdb7e4@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-08 10:39:17 -07:00
Pavel Begunkov
12521a5d5c io_uring: fix CQ waiting timeout handling
Jiffy to ktime CQ waiting conversion broke how we treat timeouts, in
particular we rearm it anew every time we get into
io_cqring_wait_schedule() without adjusting the timeout. Waiting for 2
CQEs and getting a task_work in the middle may double the timeout value,
or even worse in some cases task may wait indefinitely.

Cc: stable@vger.kernel.org
Fixes: 228339662b ("io_uring: don't convert to jiffies for waiting on timeouts")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f7bffddd71b08f28a877d44d37ac953ddb01590d.1672915663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-05 08:04:47 -07:00
Pavel Begunkov
f26cc95935 io_uring: lockdep annotate CQ locking
Locking around CQE posting is complex and depends on options the ring is
created with, add more thorough lockdep annotations checking all
invariants.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/aa3770b4eacae3915d782cc2ab2f395a99b4b232.1672795976.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-03 19:05:41 -07:00
Pavel Begunkov
9ffa13ff78 io_uring: pin context while queueing deferred tw
Unlike normal tw, nothing prevents deferred tw to be executed right
after an tw item added to ->work_llist in io_req_local_work_add(). For
instance, the waiting task may get waken up by CQ posting or a normal
tw. Thus we need to pin the ring for the rest of io_req_local_work_add()

Cc: stable@vger.kernel.org
Fixes: c0e0d6ba25 ("io_uring: add IORING_SETUP_DEFER_TASKRUN")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1a79362b9c10b8523ef70b061d96523650a23344.1672795998.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-03 19:03:28 -07:00
Jens Axboe
af82425c6a io_uring/io-wq: free worker if task_work creation is canceled
If we cancel the task_work, the worker will never come into existance.
As this is the last reference to it, ensure that we get it freed
appropriately.

Cc: stable@vger.kernel.org
Reported-by: 진호 <wnwlsgh98@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-02 16:49:46 -07:00
Jens Axboe
343190841a io_uring: check for valid register opcode earlier
We only check the register opcode value inside the restricted ring
section, move it into the main io_uring_register() function instead
and check it up front.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-23 06:40:32 -07:00
Jens Axboe
23fffb2f09 io_uring/cancel: re-grab ctx mutex after finishing wait
If we have a signal pending during cancelations, it'll cause the
task_work run to return an error. Since we didn't run task_work, the
current task is left in TASK_INTERRUPTIBLE state when we need to
re-grab the ctx mutex, and the kernel will rightfully complain about
that.

Move the lock grabbing for the error cases outside the loop to avoid
that issue.

Reported-by: syzbot+7df055631cd1be4586fd@syzkaller.appspotmail.com
Link: https://lore.kernel.org/io-uring/0000000000003a14a905f05050b0@google.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-21 13:31:40 -07:00
Jens Axboe
52ea806ad9 io_uring: finish waiting before flushing overflow entries
If we have overflow entries being generated after we've done the
initial flush in io_cqring_wait(), then we could be flushing them in the
main wait loop as well. If that's done after having added ourselves
to the cq_wait waitqueue, then the task state can be != TASK_RUNNING
when we enter the overflow flush.

Check for the need to overflow flush, and finish our wait cycle first
if we have to do so.

Reported-and-tested-by: syzbot+cf6ea1d6bb30a4ce10b2@syzkaller.appspotmail.com
Link: https://lore.kernel.org/io-uring/000000000000cb143a05f04eee15@google.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-21 08:43:53 -07:00
Pavel Begunkov
6c3e8955d4 io_uring/net: fix cleanup after recycle
Don't access io_async_msghdr io_netmsg_recycle(), it may be reallocated.

Cc: stable@vger.kernel.org
Fixes: 9bb66906f2 ("io_uring: support multishot in recvmsg")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9e326f4ad4046ddadf15bf34bf3fa58c6372f6b5.1671461985.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-19 08:28:28 -07:00
Jens Axboe
990a4de57e io_uring/net: ensure compat import handlers clear free_iov
If we're not allocating the vectors because the count is below
UIO_FASTIOV, we still do need to properly clear ->free_iov to prevent
an erronous free of on-stack data.

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Fixes: 4c17a496a7 ("io_uring/net: fix cleanup double free free_iov init")
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-19 07:35:16 -07:00
Jens Axboe
35d90f95cf io_uring: include task_work run after scheduling in wait for events
It's quite possible that we got woken up because task_work was queued,
and we need to process this task_work to generate the events waited for.
If we return to the wait loop without running task_work, we'll end up
adding the task to the waitqueue again, only to call
io_cqring_wait_schedule() again which will run the task_work. This is
less efficient than it could be, as it requires adding to the cq_wait
queue again. It also triggers the wakeup path for completions as
cq_wait is now non-empty with the task itself, and it'll require another
lock grab and deletion to remove ourselves from the waitqueue.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-17 20:35:54 -07:00
Jens Axboe
6434ec0186 io_uring: don't use TIF_NOTIFY_SIGNAL to test for availability of task_work
Use task_work_pending() as a better test for whether we have task_work
or not, TIF_NOTIFY_SIGNAL is only valid if the any of the task_work
items had been queued with TWA_SIGNAL as the notification mechanism.
Hence task_work_pending() is a more reliable check.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-17 13:40:17 -07:00
Dylan Yudaken
44a84da452 io_uring: use call_rcu_hurry if signaling an eventfd
io_uring uses call_rcu in the case it needs to signal an eventfd as a
result of an eventfd signal, since recursing eventfd signals are not
allowed. This should be calling the new call_rcu_hurry API to not delay
the signal.

Signed-off-by: Dylan Yudaken <dylany@meta.com>

Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20221215184138.795576-1-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-15 11:59:29 -07:00
Pavel Begunkov
a8cf95f936 io_uring: fix overflow handling regression
Because the single task locking series got reordered ahead of the
timeout and completion lock changes, two hunks inadvertently ended up
using __io_fill_cqe_req() rather than io_fill_cqe_req(). This meant
that we dropped overflow handling in those two spots. Reinstate the
correct CQE filling helper.

Fixes: f66f73421f ("io_uring: skip spinlocking for ->task_complete")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-15 08:20:10 -07:00
Pavel Begunkov
e5f30f6fb2 io_uring: ease timeout flush locking requirements
We don't need completion_lock for timeout flushing, don't take it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1e3dc657975ac445b80e7bdc40050db783a5935a.1670002973.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-14 08:53:35 -07:00
Pavel Begunkov
6971253f07 io_uring: revise completion_lock locking
io_kill_timeouts() doesn't post any events but queues everything to
task_work. Locking there is needed for protecting linked requests
traversing, we should grab completion_lock directly instead of using
io_cq_[un]lock helpers. Same goes for __io_req_find_next_prep().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/88e75d481a65dc295cb59722bb1cf76402d1c06b.1670002973.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-14 08:53:04 -07:00
Pavel Begunkov
ea011ee102 io_uring: protect cq_timeouts with timeout_lock
Read cq_timeouts in io_flush_timeouts() only after taking the
timeout_lock, as it's protected by it. There are many places where we
also grab ->completion_lock, but for instance io_timeout_fn() doesn't
and still modifies cq_timeouts.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9c79544dd6cf5c4018cb1bab99cf481a93ea46ef.1670002973.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-14 08:51:28 -07:00
Linus Torvalds
ce8a79d560 for-6.2/block-2022-12-08
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Merge tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe pull requests via Christoph:
      - Support some passthrough commands without CAP_SYS_ADMIN (Kanchan
        Joshi)
      - Refactor PCIe probing and reset (Christoph Hellwig)
      - Various fabrics authentication fixes and improvements (Sagi
        Grimberg)
      - Avoid fallback to sequential scan due to transient issues (Uday
        Shankar)
      - Implement support for the DEAC bit in Write Zeroes (Christoph
        Hellwig)
      - Allow overriding the IEEE OUI and firmware revision in configfs
        for nvmet (Aleksandr Miloserdov)
      - Force reconnect when number of queue changes in nvmet (Daniel
        Wagner)
      - Minor fixes and improvements (Uros Bizjak, Joel Granados, Sagi
        Grimberg, Christoph Hellwig, Christophe JAILLET)
      - Fix and cleanup nvme-fc req allocation (Chaitanya Kulkarni)
      - Use the common tagset helpers in nvme-pci driver (Christoph
        Hellwig)
      - Cleanup the nvme-pci removal path (Christoph Hellwig)
      - Use kstrtobool() instead of strtobool (Christophe JAILLET)
      - Allow unprivileged passthrough of Identify Controller (Joel
        Granados)
      - Support io stats on the mpath device (Sagi Grimberg)
      - Minor nvmet cleanup (Sagi Grimberg)

 - MD pull requests via Song:
      - Code cleanups (Christoph)
      - Various fixes

 - Floppy pull request from Denis:
      - Fix a memory leak in the init error path (Yuan)

 - Series fixing some batch wakeup issues with sbitmap (Gabriel)

 - Removal of the pktcdvd driver that was deprecated more than 5 years
   ago, and subsequent removal of the devnode callback in struct
   block_device_operations as no users are now left (Greg)

 - Fix for partition read on an exclusively opened bdev (Jan)

 - Series of elevator API cleanups (Jinlong, Christoph)

 - Series of fixes and cleanups for blk-iocost (Kemeng)

 - Series of fixes and cleanups for blk-throttle (Kemeng)

 - Series adding concurrent support for sync queues in BFQ (Yu)

 - Series bringing drbd a bit closer to the out-of-tree maintained
   version (Christian, Joel, Lars, Philipp)

 - Misc drbd fixes (Wang)

 - blk-wbt fixes and tweaks for enable/disable (Yu)

 - Fixes for mq-deadline for zoned devices (Damien)

 - Add support for read-only and offline zones for null_blk
   (Shin'ichiro)

 - Series fixing the delayed holder tracking, as used by DM (Yu,
   Christoph)

 - Series enabling bio alloc caching for IRQ based IO (Pavel)

 - Series enabling userspace peer-to-peer DMA (Logan)

 - BFQ waker fixes (Khazhismel)

 - Series fixing elevator refcount issues (Christoph, Jinlong)

 - Series cleaning up references around queue destruction (Christoph)

 - Series doing quiesce by tagset, enabling cleanups in drivers
   (Christoph, Chao)

 - Series untangling the queue kobject and queue references (Christoph)

 - Misc fixes and cleanups (Bart, David, Dawei, Jinlong, Kemeng, Ye,
   Yang, Waiman, Shin'ichiro, Randy, Pankaj, Christoph)

* tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux: (247 commits)
  blktrace: Fix output non-blktrace event when blk_classic option enabled
  block: sed-opal: Don't include <linux/kernel.h>
  sed-opal: allow using IOC_OPAL_SAVE for locking too
  blk-cgroup: Fix typo in comment
  block: remove bio_set_op_attrs
  nvmet: don't open-code NVME_NS_ATTR_RO enumeration
  nvme-pci: use the tagset alloc/free helpers
  nvme: add the Apple shared tag workaround to nvme_alloc_io_tag_set
  nvme: only set reserved_tags in nvme_alloc_io_tag_set for fabrics controllers
  nvme: consolidate setting the tagset flags
  nvme: pass nr_maps explicitly to nvme_alloc_io_tag_set
  block: bio_copy_data_iter
  nvme-pci: split out a nvme_pci_ctrl_is_dead helper
  nvme-pci: return early on ctrl state mismatch in nvme_reset_work
  nvme-pci: rename nvme_disable_io_queues
  nvme-pci: cleanup nvme_suspend_queue
  nvme-pci: remove nvme_pci_disable
  nvme-pci: remove nvme_disable_admin_queue
  nvme: merge nvme_shutdown_ctrl into nvme_disable_ctrl
  nvme: use nvme_wait_ready in nvme_shutdown_ctrl
  ...
2022-12-13 10:43:59 -08:00
Linus Torvalds
96f7e448b9 for-6.2/io_uring-next-2022-12-08
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Merge tag 'for-6.2/io_uring-next-2022-12-08' of git://git.kernel.dk/linux

Pull io_uring updates part two from Jens Axboe:

 - Misc fixes (me, Lin)

 - Series from Pavel extending the single task exclusive ring mode,
   yielding nice improvements for the common case of having a single
   ring per thread (Pavel)

 - Cleanup for MSG_RING, removing our IOPOLL hack (Pavel)

 - Further poll cleanups and fixes (Pavel)

 - Misc cleanups and fixes (Pavel)

* tag 'for-6.2/io_uring-next-2022-12-08' of git://git.kernel.dk/linux: (22 commits)
  io_uring/msg_ring: flag target ring as having task_work, if needed
  io_uring: skip spinlocking for ->task_complete
  io_uring: do msg_ring in target task via tw
  io_uring: extract a io_msg_install_complete helper
  io_uring: get rid of double locking
  io_uring: never run tw and fallback in parallel
  io_uring: use tw for putting rsrc
  io_uring: force multishot CQEs into task context
  io_uring: complete all requests in task context
  io_uring: don't check overflow flush failures
  io_uring: skip overflow CQE posting for dying ring
  io_uring: improve io_double_lock_ctx fail handling
  io_uring: dont remove file from msg_ring reqs
  io_uring: reshuffle issue_flags
  io_uring: don't reinstall quiesce node for each tw
  io_uring: improve rsrc quiesce refs checks
  io_uring: don't raw spin unlock to match cq_lock
  io_uring: combine poll tw handlers
  io_uring: improve poll warning handling
  io_uring: remove ctx variable in io_poll_check_events
  ...
2022-12-13 10:40:31 -08:00
Linus Torvalds
54e60e505d for-6.2/io_uring-2022-12-08
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Merge tag 'for-6.2/io_uring-2022-12-08' of git://git.kernel.dk/linux

Pull io_uring updates from Jens Axboe:

 - Always ensure proper ordering in case of CQ ring overflow, which then
   means we can remove some work-arounds for that (Dylan)

 - Support completion batching for multishot, greatly increasing the
   efficiency for those (Dylan)

 - Flag epoll/eventfd wakeups done from io_uring, so that we can easily
   tell if we're recursing into io_uring again.

   Previously, this would have resulted in repeated multishot
   notifications if we had a dependency there. That could happen if an
   eventfd was registered as the ring eventfd, and we multishot polled
   for events on it. Or if an io_uring fd was added to epoll, and
   io_uring had a multishot request for the epoll fd.

   Test cases here:
	https://git.kernel.dk/cgit/liburing/commit/?id=919755a7d0096fda08fb6d65ac54ad8d0fe027cd

   Previously these got terminated when the CQ ring eventually
   overflowed, now it's handled gracefully (me).

 - Tightening of the IOPOLL based completions (Pavel)

 - Optimizations of the networking zero-copy paths (Pavel)

 - Various tweaks and fixes (Dylan, Pavel)

* tag 'for-6.2/io_uring-2022-12-08' of git://git.kernel.dk/linux: (41 commits)
  io_uring: keep unlock_post inlined in hot path
  io_uring: don't use complete_post in kbuf
  io_uring: spelling fix
  io_uring: remove io_req_complete_post_tw
  io_uring: allow multishot polled reqs to defer completion
  io_uring: remove overflow param from io_post_aux_cqe
  io_uring: add lockdep assertion in io_fill_cqe_aux
  io_uring: make io_fill_cqe_aux static
  io_uring: add io_aux_cqe which allows deferred completion
  io_uring: allow defer completion for aux posted cqes
  io_uring: defer all io_req_complete_failed
  io_uring: always lock in io_apoll_task_func
  io_uring: remove iopoll spinlock
  io_uring: iopoll protect complete_post
  io_uring: inline __io_req_complete_put()
  io_uring: remove io_req_tw_post_queue
  io_uring: use io_req_task_complete() in timeout
  io_uring: hold locks for io_req_complete_failed
  io_uring: add completion locking for iopoll
  io_uring: kill io_cqring_ev_posted() and __io_cq_unlock_post()
  ...
2022-12-13 10:33:08 -08:00
Linus Torvalds
9b93f5069f fs.idmapped.mnt_idmap.v6.2
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Merge tag 'fs.idmapped.mnt_idmap.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull idmapping updates from Christian Brauner:
 "Last cycle we've already made the interaction with idmapped mounts
  more robust and type safe by introducing the vfs{g,u}id_t type. This
  cycle we concluded the conversion and removed the legacy helpers.

  Currently we still pass around the plain namespace that was attached
  to a mount. This is in general pretty convenient but it makes it easy
  to conflate namespaces that are relevant on the filesystem - with
  namespaces that are relevent on the mount level. Especially for
  filesystem developers without detailed knowledge in this area this can
  be a potential source for bugs.

  Instead of passing the plain namespace we introduce a dedicated type
  struct mnt_idmap and replace the pointer with a pointer to a struct
  mnt_idmap. There are no semantic or size changes for the mount struct
  caused by this.

  We then start converting all places aware of idmapped mounts to rely
  on struct mnt_idmap. Once the conversion is done all helpers down to
  the really low-level make_vfs{g,u}id() and from_vfs{g,u}id() will take
  a struct mnt_idmap argument instead of two namespace arguments. This
  way it becomes impossible to conflate the two removing and thus
  eliminating the possibility of any bugs. Fwiw, I fixed some issues in
  that area a while ago in ntfs3 and ksmbd in the past. Afterwards only
  low-level code can ultimately use the associated namespace for any
  permission checks. Even most of the vfs can be completely obivious
  about this ultimately and filesystems will never interact with it in
  any form in the future.

  A struct mnt_idmap currently encompasses a simple refcount and pointer
  to the relevant namespace the mount is idmapped to. If a mount isn't
  idmapped then it will point to a static nop_mnt_idmap and if it
  doesn't that it is idmapped. As usual there are no allocations or
  anything happening for non-idmapped mounts. Everthing is carefully
  written to be a nop for non-idmapped mounts as has always been the
  case.

  If an idmapped mount is created a struct mnt_idmap is allocated and a
  reference taken on the relevant namespace. Each mount that gets
  idmapped or inherits the idmap simply bumps the reference count on
  struct mnt_idmap. Just a reminder that we only allow a mount to change
  it's idmapping a single time and only if it hasn't already been
  attached to the filesystems and has no active writers.

  The actual changes are fairly straightforward but this will have huge
  benefits for maintenance and security in the long run even if it
  causes some churn.

  Note that this also makes it possible to extend struct mount_idmap in
  the future. For example, it would be possible to place the namespace
  pointer in an anonymous union together with an idmapping struct. This
  would allow us to expose an api to userspace that would let it specify
  idmappings directly instead of having to go through the detour of
  setting up namespaces at all"

* tag 'fs.idmapped.mnt_idmap.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
  acl: conver higher-level helpers to rely on mnt_idmap
  fs: introduce dedicated idmap type for mounts
2022-12-12 19:30:18 -08:00
Linus Torvalds
75f4d9af8b iov_iter work; most of that is about getting rid of
direction misannotations and (hopefully) preventing
 more of the same for the future.
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull iov_iter updates from Al Viro:
 "iov_iter work; most of that is about getting rid of direction
  misannotations and (hopefully) preventing more of the same for the
  future"

* tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  use less confusing names for iov_iter direction initializers
  iov_iter: saner checks for attempt to copy to/from iterator
  [xen] fix "direction" argument of iov_iter_kvec()
  [vhost] fix 'direction' argument of iov_iter_{init,bvec}()
  [target] fix iov_iter_bvec() "direction" argument
  [s390] memcpy_real(): WRITE is "data source", not destination...
  [s390] zcore: WRITE is "data source", not destination...
  [infiniband] READ is "data destination", not source...
  [fsi] WRITE is "data source", not destination...
  [s390] copy_oldmem_kernel() - WRITE is "data source", not destination
  csum_and_copy_to_iter(): handle ITER_DISCARD
  get rid of unlikely() on page_copy_sane() calls
2022-12-12 18:29:54 -08:00
Jens Axboe
761c61c159 io_uring/msg_ring: flag target ring as having task_work, if needed
Before the recent change, we didn't even wake the targeted task when
posting the cqe remotely. Now we do wake it, but we do want to ensure
that the recipient knows there's potential work there that needs to
get processed to get the CQE posted.

OR in IORING_SQ_TASKRUN for that purpose.

Link: https://lore.kernel.org/io-uring/2843c6b4-ba9a-b67d-e0f4-957f42098489@kernel.dk/
Fixes: 6d043ee116 ("io_uring: do msg_ring in target task via tw")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-08 09:36:02 -07:00
Pavel Begunkov
f66f73421f io_uring: skip spinlocking for ->task_complete
->task_complete was added to serialised CQE posting by doing it from
the task context only (or fallback wq when the task is dead), and now we
can use that to avoid taking ->completion_lock while filling CQ entries.
The patch skips spinlocking only in two spots,
__io_submit_flush_completions() and flushing in io_aux_cqe, it's safer
and covers all cases we care about. Extra care is taken to force taking
the lock while queueing overflow entries.

It fundamentally relies on SINGLE_ISSUER to have only one task posting
events. It also need to take into account overflowed CQEs, flushing of
which happens in the cq wait path, and so this implementation also needs
DEFER_TASKRUN to limit waiters. For the same reason we disable it for
SQPOLL, and for IOPOLL as it won't benefit from it in any case.
DEFER_TASKRUN, SQPOLL and IOPOLL requirement may be relaxed in the
future.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2a8c91fd82cfcdcc1d2e5bac7051fe2c183bda73.1670384893.git.asml.silence@gmail.com
[axboe: modify to apply]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 08:51:08 -07:00
Pavel Begunkov
6d043ee116 io_uring: do msg_ring in target task via tw
While executing in a context of one io_uring instance msg_ring
manipulates another ring. We're trying to keep CQEs posting contained in
the context of the ring-owner task, use task_work to send the request to
the target ring's task when we're modifying its CQ or trying to install
a file. Note, we can't safely use io_uring task_work infra and have to
use task_work directly.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4d76c7b28ed5d71b520de4482fbb7f660f21cd80.1670384893.git.asml.silence@gmail.com
[axboe: use TWA_SIGNAL_NO_IPI]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 08:50:57 -07:00
Pavel Begunkov
1721131016 io_uring: extract a io_msg_install_complete helper
Extract a helper called io_msg_install_complete() from io_msg_send_fd(),
will be used later.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1500ca1054cc4286a3ee1c60aacead57fcdfa02a.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
11373026f2 io_uring: get rid of double locking
We don't need to take both uring_locks at once, msg_ring can be split in
two parts, first getting a file from the filetable of the first ring and
then installing it into the second one.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a80ecc2bc99c3b3f2cf20015d618b7c51419a797.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
77e443ab29 io_uring: never run tw and fallback in parallel
Once we fallback a tw we want all requests to that task to be given to
the fallback wq so we dont run it in parallel with the last, i.e. post
PF_EXITING, tw run of the task.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/96f4987265c4312f376f206511c6af3e77aaf5ac.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
d34b1b0b67 io_uring: use tw for putting rsrc
Use task_work for completing rsrc removals, it'll be needed later for
spinlock optimisations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/cbba5d53a11ee6fc2194dacea262c1d733c8b529.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
17add5cea2 io_uring: force multishot CQEs into task context
Multishot are posting CQEs outside of the normal request completion
path, which is usually done from within a task work handler. However, it
might be not the case when it's yet to be polled but has been punted to
io-wq. Make it abide ->task_complete and push it to the polling path
when executed by io-wq.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d7714aaff583096769a0f26e8e747759e556feb1.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
e6aeb2721d io_uring: complete all requests in task context
This patch adds ctx->task_complete flag. If set, we'll complete all
requests in the context of the original task. Note, this extends to
completion CQE posting only but not io_kiocb cleanup / free, e.g. io-wq
may free the requests in the free calllback. This flag will be used
later for optimisations purposes.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/21ece72953f76bb2e77659a72a14326227ab6460.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
1b346e4aa8 io_uring: don't check overflow flush failures
The only way to fail overflowed CQEs flush is for CQ to be fully packed.
There is one place checking for flush failures, i.e. io_cqring_wait(),
but we limit the number to be waited for by the CQ size, so getting a
failure automatically means that we're done with waiting.

Don't check for failures, rarely but they might spuriously fail CQ
waiting with -EBUSY.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6b720a45c03345655517f8202cbd0bece2848fb2.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
a85381d832 io_uring: skip overflow CQE posting for dying ring
After io_ring_ctx_wait_and_kill() is called there should be no users
poking into rings and so there is no need to post CQEs. So, instead of
trying to post overflowed CQEs into the CQ, drop them. Also, do it
in io_ring_exit_work() in a loop to reduce the number of contexts it
can be executed from and even when it struggles to quiesce the ring we
won't be leaving memory allocated for longer than needed.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/26d13751155a735a3029e24f8d9ca992f810419d.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
4c979eaefa io_uring: improve io_double_lock_ctx fail handling
msg_ring will fail the request if it can't lock rings, instead punt it
to io-wq as was originally intended.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4697f05afcc37df5c8f89e2fe6d9c7c19f0241f9.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
ef0ec1ad03 io_uring: dont remove file from msg_ring reqs
We should not be messing with req->file outside of core paths. Clearing
it makes msg_ring non reentrant, i.e. luckily io_msg_send_fd() fails the
request on failed io_double_lock_ctx() but clearly was originally
intended to do retries instead.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e5ac9edadb574fe33f6d727cb8f14ce68262a684.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Harshit Mogalapalli
998b30c394 io_uring: Fix a null-ptr-deref in io_tctx_exit_cb()
Syzkaller reports a NULL deref bug as follows:

 BUG: KASAN: null-ptr-deref in io_tctx_exit_cb+0x53/0xd3
 Read of size 4 at addr 0000000000000138 by task file1/1955

 CPU: 1 PID: 1955 Comm: file1 Not tainted 6.1.0-rc7-00103-gef4d3ea40565 #75
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0xcd/0x134
  ? io_tctx_exit_cb+0x53/0xd3
  kasan_report+0xbb/0x1f0
  ? io_tctx_exit_cb+0x53/0xd3
  kasan_check_range+0x140/0x190
  io_tctx_exit_cb+0x53/0xd3
  task_work_run+0x164/0x250
  ? task_work_cancel+0x30/0x30
  get_signal+0x1c3/0x2440
  ? lock_downgrade+0x6e0/0x6e0
  ? lock_downgrade+0x6e0/0x6e0
  ? exit_signals+0x8b0/0x8b0
  ? do_raw_read_unlock+0x3b/0x70
  ? do_raw_spin_unlock+0x50/0x230
  arch_do_signal_or_restart+0x82/0x2470
  ? kmem_cache_free+0x260/0x4b0
  ? putname+0xfe/0x140
  ? get_sigframe_size+0x10/0x10
  ? do_execveat_common.isra.0+0x226/0x710
  ? lockdep_hardirqs_on+0x79/0x100
  ? putname+0xfe/0x140
  ? do_execveat_common.isra.0+0x238/0x710
  exit_to_user_mode_prepare+0x15f/0x250
  syscall_exit_to_user_mode+0x19/0x50
  do_syscall_64+0x42/0xb0
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
 RIP: 0023:0x0
 Code: Unable to access opcode bytes at 0xffffffffffffffd6.
 RSP: 002b:00000000fffb7790 EFLAGS: 00000200 ORIG_RAX: 000000000000000b
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  </TASK>
 Kernel panic - not syncing: panic_on_warn set ...

This happens because the adding of task_work from io_ring_exit_work()
isn't synchronized with canceling all work items from eg exec. The
execution of the two are ordered in that they are both run by the task
itself, but if io_tctx_exit_cb() is queued while we're canceling all
work items off exec AND gets executed when the task exits to userspace
rather than in the main loop in io_uring_cancel_generic(), then we can
find current->io_uring == NULL and hit the above crash.

It's safe to add this NULL check here, because the execution of the two
paths are done by the task itself.

Cc: stable@vger.kernel.org
Fixes: d56d938b4b ("io_uring: do ctx initiated file note removal")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20221206093833.3812138-1-harshit.m.mogalapalli@oracle.com
[axboe: add code comment and also put an explanation in the commit msg]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:45:20 -07:00
Pavel Begunkov
77e3202a21 io_uring: don't reinstall quiesce node for each tw
There is no need to reinit data and install a new rsrc node every time
we get a task_work, it's detrimental, just execute it and conitnue
waiting.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3895d3344164cd9b3a0bbb24a6e357e20a13434b.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 10:29:07 -07:00
Pavel Begunkov
0ced756f64 io_uring: improve rsrc quiesce refs checks
Do a little bit of refactoring of io_rsrc_ref_quiesce(), flatten the
data refs checks and so get rid of a conditional weird unlock-else-break
construct.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d21283e9f88a77612c746ed526d86fe3bfb58a70.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 10:29:07 -07:00
Pavel Begunkov
618d653a34 io_uring: don't raw spin unlock to match cq_lock
There is one newly added place when we lock ring with io_cq_lock() but
unlocking is hand coded calling spin_unlock directly. It's ugly and
troublesome in the long run. Make it consistent with the other completion
locking.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4ca4f0564492b90214a190cd5b2a6c76522de138.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 10:28:49 -07:00
Pavel Begunkov
443e575506 io_uring: combine poll tw handlers
Merge apoll and regular poll tw handlers, it will help with inlining.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/482e59edb9fc81bd275fdbf486837330fb27120a.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 10:27:34 -07:00
Pavel Begunkov
c3bfb57ea7 io_uring: improve poll warning handling
Don't try to complete requests if their refs are broken and we've got
a warning, it's much better to drop them and potentially leaking than
double freeing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/31edf9f96f05d03ab62c114508a231a2dce434cb.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 10:27:22 -07:00
Pavel Begunkov
047b6aef09 io_uring: remove ctx variable in io_poll_check_events
ctx is only used by io_poll_check_events() for multishot poll CQE
posting, don't save it on stack in advance.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/552c1771f8a0e7688afdb4f538ead245f53e80e7.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 10:26:57 -07:00
Pavel Begunkov
9805fa2d94 io_uring: carve io_poll_check_events fast path
The fast path in io_poll_check_events() is when we have only one
(i.e. master) reference. Move all verification, cancellations
checks, edge case handling and so on under a common if.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8c21c5d5e027e32dc553705e88796dec79ff6f93.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 10:26:57 -07:00
Pavel Begunkov
f6f7f903e7 io_uring: kill io_poll_issue's PF_EXITING check
We don't need to worry about checking PF_EXITING in io_poll_issue().
task works using the function should take care of it and never try to
resubmit / retry if the task is dying.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2e9dc998dc07507c759a0c9cb5d2fbea0710d58c.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-30 10:26:57 -07:00
Jens Axboe
b2cf789f6c Merge branch 'for-6.2/io_uring' into for-6.2/io_uring-next
* for-6.2/io_uring: (41 commits)
  io_uring: keep unlock_post inlined in hot path
  io_uring: don't use complete_post in kbuf
  io_uring: spelling fix
  io_uring: remove io_req_complete_post_tw
  io_uring: allow multishot polled reqs to defer completion
  io_uring: remove overflow param from io_post_aux_cqe
  io_uring: add lockdep assertion in io_fill_cqe_aux
  io_uring: make io_fill_cqe_aux static
  io_uring: add io_aux_cqe which allows deferred completion
  io_uring: allow defer completion for aux posted cqes
  io_uring: defer all io_req_complete_failed
  io_uring: always lock in io_apoll_task_func
  io_uring: remove iopoll spinlock
  io_uring: iopoll protect complete_post
  io_uring: inline __io_req_complete_put()
  io_uring: remove io_req_tw_post_queue
  io_uring: use io_req_task_complete() in timeout
  io_uring: hold locks for io_req_complete_failed
  io_uring: add completion locking for iopoll
  io_uring: kill io_cqring_ev_posted() and __io_cq_unlock_post()
  ...
2022-11-29 12:08:37 -07:00
Al Viro
de4eda9de2 use less confusing names for iov_iter direction initializers
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-11-25 13:01:55 -05:00
Jens Axboe
7cfe7a0948 io_uring: clear TIF_NOTIFY_SIGNAL if set and task_work not available
With how task_work is added and signaled, we can have TIF_NOTIFY_SIGNAL
set and no task_work pending as it got run in a previous loop. Treat
TIF_NOTIFY_SIGNAL like get_signal(), always clear it if set regardless
of whether or not task_work is pending to run.

Cc: stable@vger.kernel.org
Fixes: 46a525e199 ("io_uring: don't gate task_work run on TIF_NOTIFY_SIGNAL")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 10:55:08 -07:00
Lin Ma
12ad3d2d6c io_uring/poll: fix poll_refs race with cancelation
There is an interesting race condition of poll_refs which could result
in a NULL pointer dereference. The crash trace is like:

KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 30781 Comm: syz-executor.2 Not tainted 6.0.0-g493ffd6605b2 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:io_poll_remove_entry io_uring/poll.c:154 [inline]
RIP: 0010:io_poll_remove_entries+0x171/0x5b4 io_uring/poll.c:190
Code: ...
RSP: 0018:ffff88810dfefba0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc900030c4000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 0000000000000008 R08: ffffffff9764d3dd R09: fffffbfff3836781
R10: fffffbfff3836781 R11: 0000000000000000 R12: 1ffff11003422d60
R13: ffff88801a116b04 R14: ffff88801a116ac0 R15: dffffc0000000000
FS:  00007f9c07497700(0000) GS:ffff88811a600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffb5c00ea98 CR3: 0000000105680005 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 io_apoll_task_func+0x3f/0xa0 io_uring/poll.c:299
 handle_tw_list io_uring/io_uring.c:1037 [inline]
 tctx_task_work+0x37e/0x4f0 io_uring/io_uring.c:1090
 task_work_run+0x13a/0x1b0 kernel/task_work.c:177
 get_signal+0x2402/0x25a0 kernel/signal.c:2635
 arch_do_signal_or_restart+0x3b/0x660 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop kernel/entry/common.c:166 [inline]
 exit_to_user_mode_prepare+0xc2/0x160 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x58/0x160 kernel/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The root cause for this is a tiny overlooking in
io_poll_check_events() when cocurrently run with poll cancel routine
io_poll_cancel_req().

The interleaving to trigger use-after-free:

CPU0                                       |  CPU1
                                           |
io_apoll_task_func()                       |  io_poll_cancel_req()
 io_poll_check_events()                    |
  // do while first loop                   |
  v = atomic_read(...)                     |
  // v = poll_refs = 1                     |
  ...                                      |  io_poll_mark_cancelled()
                                           |   atomic_or()
                                           |   // poll_refs =
IO_POLL_CANCEL_FLAG | 1
                                           |
  atomic_sub_return(...)                   |
  // poll_refs = IO_POLL_CANCEL_FLAG       |
  // loop continue                         |
                                           |
                                           |  io_poll_execute()
                                           |   io_poll_get_ownership()
                                           |   // poll_refs =
IO_POLL_CANCEL_FLAG | 1
                                           |   // gets the ownership
  v = atomic_read(...)                     |
  // poll_refs not change                  |
                                           |
  if (v & IO_POLL_CANCEL_FLAG)             |
   return -ECANCELED;                      |
  // io_poll_check_events return           |
  // will go into                          |
  // io_req_complete_failed() free req     |
                                           |
                                           |  io_apoll_task_func()
                                           |  // also go into
io_req_complete_failed()

And the interleaving to trigger the kernel WARNING:

CPU0                                       |  CPU1
                                           |
io_apoll_task_func()                       |  io_poll_cancel_req()
 io_poll_check_events()                    |
  // do while first loop                   |
  v = atomic_read(...)                     |
  // v = poll_refs = 1                     |
  ...                                      |  io_poll_mark_cancelled()
                                           |   atomic_or()
                                           |   // poll_refs =
IO_POLL_CANCEL_FLAG | 1
                                           |
  atomic_sub_return(...)                   |
  // poll_refs = IO_POLL_CANCEL_FLAG       |
  // loop continue                         |
                                           |
  v = atomic_read(...)                     |
  // v = IO_POLL_CANCEL_FLAG               |
                                           |  io_poll_execute()
                                           |   io_poll_get_ownership()
                                           |   // poll_refs =
IO_POLL_CANCEL_FLAG | 1
                                           |   // gets the ownership
                                           |
  WARN_ON_ONCE(!(v & IO_POLL_REF_MASK)))   |
  // v & IO_POLL_REF_MASK = 0 WARN         |
                                           |
                                           |  io_apoll_task_func()
                                           |  // also go into
io_req_complete_failed()

By looking up the source code and communicating with Pavel, the
implementation of this atomic poll refs should continue the loop of
io_poll_check_events() just to avoid somewhere else to grab the
ownership. Therefore, this patch simply adds another AND operation to
make sure the loop will stop if it finds the poll_refs is exactly equal
to IO_POLL_CANCEL_FLAG. Since io_poll_cancel_req() grabs ownership and
will finally make its way to io_req_complete_failed(), the req will
be reclaimed as expected.

Fixes: aa43477b04 ("io_uring: poll rework")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
[axboe: tweak description and code style]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 07:17:33 -07:00
Lin Ma
9d94c04c0d io_uring/filetable: fix file reference underflow
There is an interesting reference bug when -ENOMEM occurs in calling of
io_install_fixed_file(). KASan report like below:

[   14.057131] ==================================================================
[   14.059161] BUG: KASAN: use-after-free in unix_get_socket+0x10/0x90
[   14.060975] Read of size 8 at addr ffff88800b09cf20 by task kworker/u8:2/45
[   14.062684]
[   14.062768] CPU: 2 PID: 45 Comm: kworker/u8:2 Not tainted 6.1.0-rc4 #1
[   14.063099] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   14.063666] Workqueue: events_unbound io_ring_exit_work
[   14.063936] Call Trace:
[   14.064065]  <TASK>
[   14.064175]  dump_stack_lvl+0x34/0x48
[   14.064360]  print_report+0x172/0x475
[   14.064547]  ? _raw_spin_lock_irq+0x83/0xe0
[   14.064758]  ? __virt_addr_valid+0xef/0x170
[   14.064975]  ? unix_get_socket+0x10/0x90
[   14.065167]  kasan_report+0xad/0x130
[   14.065353]  ? unix_get_socket+0x10/0x90
[   14.065553]  unix_get_socket+0x10/0x90
[   14.065744]  __io_sqe_files_unregister+0x87/0x1e0
[   14.065989]  ? io_rsrc_refs_drop+0x1c/0xd0
[   14.066199]  io_ring_exit_work+0x388/0x6a5
[   14.066410]  ? io_uring_try_cancel_requests+0x5bf/0x5bf
[   14.066674]  ? try_to_wake_up+0xdb/0x910
[   14.066873]  ? virt_to_head_page+0xbe/0xbe
[   14.067080]  ? __schedule+0x574/0xd20
[   14.067273]  ? read_word_at_a_time+0xe/0x20
[   14.067492]  ? strscpy+0xb5/0x190
[   14.067665]  process_one_work+0x423/0x710
[   14.067879]  worker_thread+0x2a2/0x6f0
[   14.068073]  ? process_one_work+0x710/0x710
[   14.068284]  kthread+0x163/0x1a0
[   14.068454]  ? kthread_complete_and_exit+0x20/0x20
[   14.068697]  ret_from_fork+0x22/0x30
[   14.068886]  </TASK>
[   14.069000]
[   14.069088] Allocated by task 289:
[   14.069269]  kasan_save_stack+0x1e/0x40
[   14.069463]  kasan_set_track+0x21/0x30
[   14.069652]  __kasan_slab_alloc+0x58/0x70
[   14.069899]  kmem_cache_alloc+0xc5/0x200
[   14.070100]  __alloc_file+0x20/0x160
[   14.070283]  alloc_empty_file+0x3b/0xc0
[   14.070479]  path_openat+0xc3/0x1770
[   14.070689]  do_filp_open+0x150/0x270
[   14.070888]  do_sys_openat2+0x113/0x270
[   14.071081]  __x64_sys_openat+0xc8/0x140
[   14.071283]  do_syscall_64+0x3b/0x90
[   14.071466]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[   14.071791]
[   14.071874] Freed by task 0:
[   14.072027]  kasan_save_stack+0x1e/0x40
[   14.072224]  kasan_set_track+0x21/0x30
[   14.072415]  kasan_save_free_info+0x2a/0x50
[   14.072627]  __kasan_slab_free+0x106/0x190
[   14.072858]  kmem_cache_free+0x98/0x340
[   14.073075]  rcu_core+0x427/0xe50
[   14.073249]  __do_softirq+0x110/0x3cd
[   14.073440]
[   14.073523] Last potentially related work creation:
[   14.073801]  kasan_save_stack+0x1e/0x40
[   14.074017]  __kasan_record_aux_stack+0x97/0xb0
[   14.074264]  call_rcu+0x41/0x550
[   14.074436]  task_work_run+0xf4/0x170
[   14.074619]  exit_to_user_mode_prepare+0x113/0x120
[   14.074858]  syscall_exit_to_user_mode+0x1d/0x40
[   14.075092]  do_syscall_64+0x48/0x90
[   14.075272]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[   14.075529]
[   14.075612] Second to last potentially related work creation:
[   14.075900]  kasan_save_stack+0x1e/0x40
[   14.076098]  __kasan_record_aux_stack+0x97/0xb0
[   14.076325]  task_work_add+0x72/0x1b0
[   14.076512]  fput+0x65/0xc0
[   14.076657]  filp_close+0x8e/0xa0
[   14.076825]  __x64_sys_close+0x15/0x50
[   14.077019]  do_syscall_64+0x3b/0x90
[   14.077199]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[   14.077448]
[   14.077530] The buggy address belongs to the object at ffff88800b09cf00
[   14.077530]  which belongs to the cache filp of size 232
[   14.078105] The buggy address is located 32 bytes inside of
[   14.078105]  232-byte region [ffff88800b09cf00, ffff88800b09cfe8)
[   14.078685]
[   14.078771] The buggy address belongs to the physical page:
[   14.079046] page:000000001bd520e7 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88800b09de00 pfn:0xb09c
[   14.079575] head:000000001bd520e7 order:1 compound_mapcount:0 compound_pincount:0
[   14.079946] flags: 0x100000000010200(slab|head|node=0|zone=1)
[   14.080244] raw: 0100000000010200 0000000000000000 dead000000000001 ffff88800493cc80
[   14.080629] raw: ffff88800b09de00 0000000080190018 00000001ffffffff 0000000000000000
[   14.081016] page dumped because: kasan: bad access detected
[   14.081293]
[   14.081376] Memory state around the buggy address:
[   14.081618]  ffff88800b09ce00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   14.081974]  ffff88800b09ce80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
[   14.082336] >ffff88800b09cf00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   14.082690]                                ^
[   14.082909]  ffff88800b09cf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
[   14.083266]  ffff88800b09d000: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
[   14.083622] ==================================================================

The actual tracing of this bug is shown below:

commit 8c71fe7502 ("io_uring: ensure fput() called correspondingly
when direct install fails") adds an additional fput() in
io_fixed_fd_install() when io_file_bitmap_get() returns error values. In
that case, the routine will never make it to io_install_fixed_file() due
to an early return.

static int io_fixed_fd_install(...)
{
  if (alloc_slot) {
    ...
    ret = io_file_bitmap_get(ctx);
    if (unlikely(ret < 0)) {
      io_ring_submit_unlock(ctx, issue_flags);
      fput(file);
      return ret;
    }
    ...
  }
  ...
  ret = io_install_fixed_file(req, file, issue_flags, file_slot);
  ...
}

In the above scenario, the reference is okay as io_fixed_fd_install()
ensures the fput() is called when something bad happens, either via
bitmap or via inner io_install_fixed_file().

However, the commit 61c1b44a21 ("io_uring: fix deadlock on iowq file
slot alloc") breaks the balance because it places fput() into the common
path for both io_file_bitmap_get() and io_install_fixed_file(). Since
io_install_fixed_file() handles the fput() itself, the reference
underflow come across then.

There are some extra commits make the current code into
io_fixed_fd_install() -> __io_fixed_fd_install() ->
io_install_fixed_file()

However, the fact that there is an extra fput() is called if
io_install_fixed_file() calls fput(). Traversing through the code, I
find that the existing two callers to __io_fixed_fd_install():
io_fixed_fd_install() and io_msg_send_fd() have fput() when handling
error return, this patch simply removes the fput() in
io_install_fixed_file() to fix the bug.

Fixes: 61c1b44a21 ("io_uring: fix deadlock on iowq file slot alloc")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Link: https://lore.kernel.org/r/be4ba4b.5d44.184a0a406a4.Coremail.linma@zju.edu.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:54:46 -07:00
Pavel Begunkov
a26a35e901 io_uring: make poll refs more robust
poll_refs carry two functions, the first is ownership over the request.
The second is notifying the io_poll_check_events() that there was an
event but wake up couldn't grab the ownership, so io_poll_check_events()
should retry.

We want to make poll_refs more robust against overflows. Instead of
always incrementing it, which covers two purposes with one atomic, check
if poll_refs is elevated enough and if so set a retry flag without
attempts to grab ownership. The gap between the bias check and following
atomics may seem racy, but we don't need it to be strict. Moreover there
might only be maximum 4 parallel updates: by the first and the second
poll entries, __io_arm_poll_handler() and cancellation. From those four,
only poll wake ups may be executed multiple times, but they're protected
by a spin.

Cc: stable@vger.kernel.org
Reported-by: Lin Ma <linma@zju.edu.cn>
Fixes: aa43477b04 ("io_uring: poll rework")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c762bc31f8683b3270f3587691348a7119ef9c9d.1668963050.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:54:46 -07:00
Pavel Begunkov
2f3893437a io_uring: cmpxchg for poll arm refs release
Replace atomically substracting the ownership reference at the end of
arming a poll with a cmpxchg. We try to release ownership by setting 0
assuming that poll_refs didn't change while we were arming. If it did
change, we keep the ownership and use it to queue a tw, which is fully
capable to process all events and (even tolerates spurious wake ups).

It's a bit more elegant as we reduce races b/w setting the cancellation
flag and getting refs with this release, and with that we don't have to
worry about any kinds of underflows. It's not the fastest path for
polling. The performance difference b/w cmpxchg and atomic dec is
usually negligible and it's not the fastest path.

Cc: stable@vger.kernel.org
Fixes: aa43477b04 ("io_uring: poll rework")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0c95251624397ea6def568ff040cad2d7926fd51.1668963050.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:54:16 -07:00
Pavel Begunkov
5d77291685 io_uring: keep unlock_post inlined in hot path
This partially reverts

6c16fe3c16 ("io_uring: kill io_cqring_ev_posted() and __io_cq_unlock_post()")

The redundancy of __io_cq_unlock_post() was always to keep it inlined
into __io_submit_flush_completions(). Inline it back and rename with
hope of clarifying the intention behind it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/372a16c485fca44c069be2e92fc5e7332a1d7fd7.1669310258.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:11:15 -07:00
Pavel Begunkov
c3b490930d io_uring: don't use complete_post in kbuf
Now we're handling IOPOLL completions more generically, get rid uses of
_post() and send requests through the normal path. It may have some
extra mertis performance wise, but we don't care much as there is a
better interface for selected buffers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4deded706587f55b006dc33adf0c13cfc3b2319f.1669310258.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:11:15 -07:00
Dylan Yudaken
10d8bc3541 io_uring: spelling fix
s/pushs/pushes/

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221125103412.1425305-3-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:46 -07:00
Dylan Yudaken
27f35fe909 io_uring: remove io_req_complete_post_tw
It's only used in one place. Inline it.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221125103412.1425305-2-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:46 -07:00
Dylan Yudaken
9a6924519e io_uring: allow multishot polled reqs to defer completion
Until now there was no reason for multishot polled requests to defer
completions as there was no functional difference. However now this will
actually defer the completions, for a performance win.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-10-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:04 -07:00
Dylan Yudaken
b529c96a89 io_uring: remove overflow param from io_post_aux_cqe
The only call sites which would not allow overflow are also call sites
which would use the io_aux_cqe as they care about ordering.

So remove this parameter from io_post_aux_cqe.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-9-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:04 -07:00
Dylan Yudaken
2e2ef4a1da io_uring: add lockdep assertion in io_fill_cqe_aux
Add an assertion for the completion lock to io_fill_cqe_aux

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-8-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:04 -07:00
Dylan Yudaken
a77ab745f2 io_uring: make io_fill_cqe_aux static
This is only used in io_uring.c

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-7-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:04 -07:00
Dylan Yudaken
9b8c54755a io_uring: add io_aux_cqe which allows deferred completion
Use the just introduced deferred post cqe completion state when possible
in io_aux_cqe. If not possible fallback to io_post_aux_cqe.

This introduces a complication because of allow_overflow. For deferred
completions we cannot know without locking the completion_lock if it will
overflow (and even if we locked it, another post could sneak in and cause
this cqe to be in overflow).
However since overflow protection is mostly a best effort defence in depth
to prevent infinite loops of CQEs for poll, just checking the overflow bit
is going to be good enough and will result in at most 16 (array size of
deferred cqes) overflows.

Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-6-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:04 -07:00
Dylan Yudaken
931147ddfa io_uring: allow defer completion for aux posted cqes
Multishot ops cannot use the compl_reqs list as the request must stay in
the poll list, but that means they need to run each completion without
benefiting from batching.

Here introduce batching infrastructure for only small (ie 16 byte)
CQEs. This restriction is ok because there are no use cases posting 32
byte CQEs.

In the ring keep a batch of up to 16 posted results, and flush in the same
way as compl_reqs.

16 was chosen through experimentation on a microbenchmark ([1]), as well
as trying not to increase the size of the ring too much. This increases
the size to 1472 bytes from 1216.

[1]: 9ac66b36bc
Run with $ make -j && ./benchmark/reg.b -s 1 -t 2000 -r 10
Gives results:
baseline	8309 k/s
8		18807 k/s
16		19338 k/s
32		20134 k/s

Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-5-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:04 -07:00
Dylan Yudaken
973fc83f3a io_uring: defer all io_req_complete_failed
All failures happen under lock now, and can be deferred. To be consistent
when the failure has happened after some multishot cqe has been
deferred (and keep ordering), always defer failures.

To make this obvious at the caller (and to help prevent a future bug)
rename io_req_complete_failed to io_req_defer_failed.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-4-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:04 -07:00
Dylan Yudaken
c06c6c5d27 io_uring: always lock in io_apoll_task_func
This is required for the failure case (io_req_complete_failed) and is
missing.

The alternative would be to only lock in the failure path, however all of
the non-error paths in io_poll_check_events that do not do not return
IOU_POLL_NO_ACTION end up locking anyway. The only extraneous lock would
be for the multishot poll overflowing the CQE ring, however multishot poll
would probably benefit from being locked as it will allow completions to
be batched.

So it seems reasonable to lock always.

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-3-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-25 06:10:04 -07:00
Pavel Begunkov
2dac1a1592 io_uring: remove iopoll spinlock
This reverts commit 2ccc92f4ef

io_req_complete_post() should now behave well even in case of IOPOLL, we
can remove completion_lock locking.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7e171c8b530656b14a671c59100ca260e46e7f2a.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-23 10:47:07 -07:00
Pavel Begunkov
1bec951c38 io_uring: iopoll protect complete_post
io_req_complete_post() may be used by iopoll enabled rings, grab locks
in this case. That requires to pass issue_flags to propagate the locking
state.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/cc6d854065c57c838ca8e8806f707a226b70fd2d.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-23 10:45:31 -07:00
Pavel Begunkov
fa18fa2272 io_uring: inline __io_req_complete_put()
Inline __io_req_complete_put() into io_req_complete_post(), there are no
other users.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1923a4dfe80fa877f859a22ed3df2d5fc8ecf02b.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-23 10:44:01 -07:00
Pavel Begunkov
833b5dfffc io_uring: remove io_req_tw_post_queue
Remove io_req_tw_post() and io_req_tw_post_queue(), we can use
io_req_task_complete() instead.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b9b73c08022c7f1457023ac841f35c0100e70345.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-23 10:44:00 -07:00
Pavel Begunkov
624fd779fd io_uring: use io_req_task_complete() in timeout
Use a more generic io_req_task_complete() in timeout completion
task_work instead of io_req_complete_post().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bda1710b58c07bf06107421c2a65c529ea9cdcac.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-23 10:44:00 -07:00
Pavel Begunkov
e276ae344a io_uring: hold locks for io_req_complete_failed
A preparation patch, make sure we always hold uring_lock around
io_req_complete_failed(). The only place deviating from the rule
is io_cancel_defer_files(), queue a tw instead.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/70760344eadaecf2939287084b9d4ba5c05a6984.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-23 10:44:00 -07:00
Pavel Begunkov
2ccc92f4ef io_uring: add completion locking for iopoll
There are pieces of code that may allow iopoll to race filling cqes,
temporarily add spinlocking around posting events.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/84d86b5c117feda075471c5c9e65208e0dccf5d0.1669203009.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-23 10:44:00 -07:00
Jens Axboe
6c16fe3c16 io_uring: kill io_cqring_ev_posted() and __io_cq_unlock_post()
__io_cq_unlock_post() is identical to io_cq_unlock_post(), and
io_cqring_ev_posted() has a single caller so migth as well just inline
it there.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-22 06:09:30 -07:00
Jens Axboe
4061f0ef73 Revert "io_uring: disallow self-propelled ring polling"
This reverts commit 7fdbc5f014.

This patch dealt with a subset of the real problem, which is a potential
circular dependency on the wakup path for io_uring itself. Outside of
io_uring, eventfd can also trigger this (see details in 03e02acda8)
and so can epoll (see details in caf1aeaffc). Now that we have a
generic solution to this problem, get rid of the io_uring specific
work-around.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-22 06:08:31 -07:00
Jens Axboe
4464853277 io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups
Pass in EPOLL_URING_WAKE when signaling eventfd or doing poll related
wakups, so that we can check for a circular event dependency between
eventfd and epoll. If this flag is set when our wakeup handlers are
called, then we know we have a dependency that needs to terminate
multishot requests.

eventfd and epoll are the only such possible dependencies.

Cc: stable@vger.kernel.org # 6.0
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-22 06:08:31 -07:00
Pavel Begunkov
f9d567c75e io_uring: inline __io_req_complete_post()
There is only one user of __io_req_complete_post(), inline it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ef4c9059950a3da5cf68df00f977f1fd13bd9306.1668597569.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-21 07:45:19 -07:00
Pavel Begunkov
d759360620 io_uring: split tw fallback into a function
When the target process is dying and so task_work_add() is not allowed
we push all task_work item to the fallback workqueue. Move the part
responsible for moving tw items out of __io_req_task_work_add() into
a separate function. Makes it a bit cleaner and gives the compiler a bit
of extra info.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e503dab9d7af95470ca6b214c6de17715ae4e748.1668162751.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-21 07:44:21 -07:00