Commit Graph

1716 Commits

Author SHA1 Message Date
Pavel Begunkov 5a158c6b0d io_uring: reshuffle io_submit_state bits
struct io_submit_state's ->free_list and ->link are hotter and smaller
than ->plug, place them first.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6ad3c15849f50b27ad012c042c73e6e069d22df7.1633532552.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:55 -06:00
Pavel Begunkov 756ab7c0ec io_uring: safer fallback_work free
Add extra wq flushing for fallback_work, that's not necessary but safer
if invariants of io_fallback_req_func() change.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/24179419d6748516299600bc914f50b9e0b02275.1633532552.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:55 -06:00
Pavel Begunkov 6d63416dc5 io_uring: optimise plugging
Plugging is only needed with requests that also need a file, so hide
plugging under a ->needs_file check. Also, place ->needs_file and ->plug
bits into the same byte of io_op_defs, it may matter for compilers, e.g.
only with the change a tested one decided to optimise two memory testb
into a more with two register testb.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1600d1287bb7d16451d4ef3343252787a5314927.1633532552.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:55 -06:00
Pavel Begunkov 54daa9b2d8 io_uring: correct fill events helpers types
CQE result is a 32-bit integer, so the functions generating CQEs are
better to accept not long but ints. Convert io_cqring_fill_event() and
other helpers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7ca6f15255e9117eae28adcac272744cae29b113.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:55 -06:00
Pavel Begunkov eb6e6f0690 io_uring: inline io_poll_complete
Inline io_poll_complete(), it's simple and doesn't have any particular
purpose.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/933d7ee3e4450749a2d892235462c8f18d030293.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:55 -06:00
Pavel Begunkov 867f8fa5ae io_uring: inline io_req_needs_clean()
There is only a single user of io_req_needs_clean() inline it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6111d0221ef4b439cad401e135dd6a5f990a0501.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov d17e56eb49 io_uring: remove struct io_completion
We keep struct io_completion only as a temporal storage of cflags, Place
it in io_kiocb, it's cleaner, removes extra bits and even might be used
for future optimisations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5299bd5c223204065464bd87a515d0e405316086.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov d886e185a1 io_uring: control ->async_data with a REQ_F flag
->async_data is a slow path, so it won't matter much if we do the clean
up inside io_clean_op(). Moreover, in many cases it's allocated together
with setting one or more of IO_REQ_CLEAN_FLAGS flags, so it'd go through
io_clean_op() anyway.

Control ->async_data allocation with a new flag REQ_F_ASYNC_DATA, so we
can do all the maintainence under io_req_needs_clean() fast check.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6892cf5883c459f36bda26f30ceb16742b20b84b.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov c1e53a6988 io_uring: optimise io_free_batch_list()
Delay reading the next node in io_free_batch_list(), allows the compiler
to load the value a bit later improving register spilling in some cases.
With gcc 11.1 it helped to move @task_refs variable from the stack to a
register and optimises out a couple of per request instructions.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/cc9fdfb6f72a4e8bc9918a5e9f2d97869a263ae4.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov c072481ded io_uring: mark cold functions
Attribute cold functions so compilers can optimise them for size. It
shrinks the binary by 2.5-3%

   text    data     bss     dec     hex filename
  90670   14002       8  104680   198e8 ./fs/io_uring.o
  88053   14002       8  102063   18eaf ./fs/io_uring.o

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b53d385f91dca45170b67d7f11c7abd787e821f6.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov 37f0e767e1 io_uring: optimise ctx referencing by requests
Currenlty, we allocate one ctx reference per request at submission time
and put them at free. It's batched and not so expensive but it still
bloats the kernel, adds 2 function calls for rcu and adds some overhead
for request counting in io_free_batch_list().

Always keep one reference with a request, even when it's freed and in
io_uring request caches. There is extra work at ring exit / quiesce
paths, which now need to put all cached requests. io_ring_exit_work() is
already looping, so it's not a problem. Add hybrid-busy waiting to
io_ctx_quiesce() as well for now.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/99613fbe396e80777228cde39bbda1aa8938554e.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov d60aa65ba2 io_uring: merge CQ and poll waitqueues
->cq_wait and ->poll_wait and waken up in the same manner, use a single
waitqueue for both of them. CQ waiters are queued exclusively, so wake
up should first go over all pollers and that's what we need.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/00fe603e50000365774cf8435ef5fe03f049c1c9.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov aede728aae io_uring: don't wake sqpoll in io_cqring_ev_posted
io_cqring_ev_posted() doesn't need to wake SQPOLL, it's either done by
userspace or with task_work, but no action is required on request
completion. Rip off bits waking it up in io_cqring_ev_posted().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b49dab27b64cf11f4c50f2f90dcaac123430e05d.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov a33ae9ce16 io_uring: optimise request allocation
Even after fully inlining io_alloc_req() my compiler does a NULL check
in the path of successful allocation, no hacks like an empty dereference
help it. Restructure io_alloc_req() by splitting out refilling part, so
the compiler generate a slightly better binary.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/eda17571bdc7248d8e617b23e7132a5416e4680b.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov fff4e40e30 io_uring: delay req queueing into compl-batch list
io_req_complete_state() is inlined and used in lots of places, so we
want to keep it concise. Move adding a request into a completion batch
list from io_req_complete_state() into the consumer, i.e.
__io_queue_sqe().

before vs after
   text    data     bss     dec     hex filename
  91894   14002       8  105904   19db0 ./fs/io_uring.o
  91046   14002       8  105056   19a60 ./fs/io_uring.o

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4afca4e11abfd4cc8e99777fdcaf4d34cf4d022d.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov 51d48dab62 io_uring: add more likely/unlikely() annotations
Add two extra unlikely() in io_submit_sqes() and one around
io_req_needs_clean() to help the compiler to avoid extra jumps
in hot paths.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/88e087afe657e7660194353aada9b00f11d480f9.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov 7e3709d576 io_uring: optimise kiocb layout
We want ->comp_list in the second cacheline, which is hotter comparing
to the 3rd. Swap the field with ->link, which is not as hot and
controlled by flags and so not accessed unless there is a link.

By the way add a couple of comments for io_kiocb fields.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9d9dde31f8f62279a5f48c575bbc27b8290edc0c.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov 6224590d24 io_uring: add flag to not fail link after timeout
For some reason non-off IORING_OP_TIMEOUT always fails links, it's
pretty inconvenient and unnecessary limits chaining after it to hard
linking, which is far from ideal, e.g. doesn't pair well with timeout
cancellation. Add a flag forcing it to not fail links on -ETIME.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/17c7ec0fb7a6113cc6be8cdaedcada0ba836ac0e.1633199723.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov 30d51dd4ad io_uring: clean up buffer select
Hiding a pointer to a struct io_buffer in rw.addr is error prone. We
have some place in io_kiocb, so keep kbuf's in a separate field
without aliasing and risks of it being misused.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3e63a6a953b04cad81d9ea827b12344dd57b37b4.1633107393.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov fc0ae0244b io_uring: init opcode in io_init_req()
Move io_req_prep() call inside of io_init_req(), it simplifies a bit
error handling for callers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a0f59291fd52da4672c323542fd56fd899e23f8f.1633107393.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov e0eb71dcfc io_uring: don't return from io_drain_req()
Never return from io_drain_req() but punt to tw if we've got there but
it's a false positive and we shouldn't actually drain.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/93583cee51b8783706b76c73196c155b28d9e762.1633107393.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov 22b2ca310a io_uring: extra a helper for drain init
Add a helper io_init_req_drain for initialising requests with
IOSQE_DRAIN set. Also move bits from preambule of io_drain_req() in
there, because we already modify all the bits needed inside the helper.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dcb412825b35b1cb8891245a387d7d69f8d14cef.1633107393.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov 5e371265ea io_uring: disable draining earlier
Clear ->drain_active in two more cases where we check for a need of
draining. It's not a bug, but still may lead to some extra requests
being punted to io-wq, and that may be not desirable.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d20b265f77bb4e8860b15b9987252c7c711dfcba.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov a1cdbb4cb5 io_uring: comment why inline complete calls io_clean_op()
io_req_complete_state() calls io_clean_op() and it may be not entirely
obvious, leave a comment.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/21806f862151e223fdf439e5e8ed7178a8d66979.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov ef05d9ebcc io_uring: kill off ->inflight_entry field
->inflight_entry is not used anymore after converting everything to
single linked lists, remove it. Also adjust io_kiocb layout, so all hot
bits are in first 3 cachelines.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fd8d68087ede26c4e1707ce6b175aa1eb2381f2b.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov 6962980947 io_uring: restructure submit sqes to_submit checks
Put an explicit check for number of requests to submit. First,
we can turn while into do-while and it generates better code, and second
that if can be cheaper, e.g. by using CPU flags after sub in
io_sqring_entries().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5926baadd20c28feab7a5e1725fedf32e4553ff7.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov d9f9d2842c io_uring: reshuffle queue_sqe completion handling
If a request completed inline the result should only be zero, it's a
grave error otherwise. So, when we see REQ_F_COMPLETE_INLINE it's not
even necessary to check the return code, and the flag check can be moved
earlier.

It's one "if" less for inline completions, and same two checks for it
normally completing (ret == 0). Those are two cases we care about the
most.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ebd4e397a9c26d96c99b24447acc309741041a83.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:54 -06:00
Pavel Begunkov d475a9a622 io_uring: inline hot path of __io_queue_sqe()
Extract slow paths from __io_queue_sqe() into a function and inline the
hot path. With that we have everything completely inlined on the
submission path up until io_issue_sqe().

-> io_submit_sqes()
  -> io_submit_sqe() (inlined)
    -> io_queue_sqe() (inlined)
       -> __io_queue_sqe() (inlined)
         -> io_issue_sqe()

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f1606864d95d7f26dc28c7eec3dc6ed6ec32618a.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 4652fe3f10 io_uring: split slow path from io_queue_sqe
We don't want the slow path of io_queue_sqe to be inlined, so extract a
function from it.

   text    data     bss     dec     hex filename
  91950   13986       8  105944   19dd8 ./fs/io_uring.o
  91758   13986       8  105752   19d18 ./fs/io_uring.o

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fb01253911f8fb374268f65b1ba939b54ca6583f.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 2a56a9bd64 io_uring: remove drain_active check from hot path
req->ctx->active_drain is a bit too expensive, partially because of two
dereferences. Do a trick, if we see it set in io_init_req(), set
REQ_F_FORCE_ASYNC and it automatically goes through a slower path where
we can catch it. It's nearly free to do in io_init_req() because there
is already ->restricted check and it's in the same byte of a bitmask.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d7e7ddc63c15e8a300833132abb3eb8fd3918aef.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov f15a343177 io_uring: deduplicate io_queue_sqe() call sites
There are two call sites of io_queue_sqe() in io_submit_sqe(), combine
them into one, because io_queue_sqe() is inline and we don't want to
bloat binary, and will become even bigger

   text    data     bss     dec     hex filename
  92126   13986       8  106120   19e88 ./fs/io_uring.o
  91966   13986       8  105960   19de8 ./fs/io_uring.o

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/506124b8e767f0a4576f7a459f6aea3d13fb4dda.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 553deffd09 io_uring: don't pass state to io_submit_state_end
Submission state and ctx and coupled together, no need to passs

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e22d77a5786ef77e0c49b933ad74bae55cfb6ca6.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 1cce17aca6 io_uring: don't pass tail into io_free_batch_list
io_free_batch_list() iterates all requests in the passed in list,
so we don't really need to know the tail but can keep iterating until
meet NULL. Just pass the first node into it and it will be enough.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4a12c84b6d887d980e05f417ba4172d04c64acae.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov d4b7a5ef2b io_uring: inline completion batching helpers
We now have a single function for batched put of requests, just inline
struct req_batch and all related helpers into it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/595a2917f80dd94288cd7203052c7934f5446580.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov f5ed3bcd5b io_uring: optimise batch completion
First, convert rest of iopoll bits to single linked lists, and also
replace per-request list_add_tail() with splicing a part of slist.

With that, use io_free_batch_list() to put/free requests. The main
advantage of it is that it's now the only user of struct req_batch and
friends, and so they can be inlined. The main overhead there was
per-request call to not-inlined io_req_free_batch(), which is expensive
enough.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b37fc6d5954b241e025eead7ab92c6f44a42f229.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov b3fa03fd1b io_uring: convert iopoll_completed to store_release
Convert explicit barrier around iopoll_completed to smp_load_acquire()
and smp_store_release(). Similar on the callback side, but replaces a
single smp_rmb() with per-request smp_load_acquire(), neither imply any
extra CPU ordering for x86. Use READ_ONCE as usual where it doesn't
matter.

Use it to move filling CQEs by iopoll earlier, that will be necessary
to avoid traversing the list one extra time in the future.

Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8bd663cb15efdc72d6247c38ee810964e744a450.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 3aa83bfb6e io_uring: add a helper for batch free
Add a helper io_free_batch_list(), which takes a single linked list and
puts/frees all requests from it in an efficient manner. Will be reused
later.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4fc8306b542c6b1dd1d08e8021ef3bdb0ad15010.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 5eef4e87eb io_uring: use single linked list for iopoll
Use single linked lists for keeping iopoll requests, takes less space,
may be faster, but mostly will be of benefit for further patches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/314033676b100cd485518c3bc55e1b95a0dcd71f.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov e3f721e6f6 io_uring: split iopoll loop
The main loop of io_do_iopoll() iterates and does ->iopoll() until it
meets a first completed request, then it continues from that position
and splices requests to pass them through io_iopoll_complete().

Split the loop in two for clearness, iopolling and reaping completed
requests from the list.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a7f6fd27a94845e5dc925a47a4a9765a92e514fb.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov c2b6c6bc4e io_uring: replace list with stack for req caches
Replace struct list_head free_list serving for caching requests with
singly linked stack, which is faster.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1bc942b82422fb2624b8353bd93aca183a022846.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 3ab665b74e io_uring: remove allocation cache array
We have several of request allocation layers, remove the last one, which
is the submit->reqs array, and always use submit->free_reqs instead.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8547095c35f7a87bab14f6447ecd30a273ed7500.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 6f33b0bc4e io_uring: use slist for completion batching
Currently we collect requests for completion batching in an array.
Replace them with a singly linked list. It's as fast as arrays but
doesn't take some much space in ctx, and will be used in future patches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a666826f2854d17e9fb9417fb302edfeb750f425.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 5ba3c874eb io_uring: make io_do_iopoll return number of reqs
Don't pass nr_events pointer around but return directly, it's less
expensive than pointer increments.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f771a8153a86f16f12ff4272524e9e549c5de40b.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 87a115fb71 io_uring: force_nonspin
We don't really need to pass the number of requests to complete into
io_do_iopoll(), a flag whether to enforce non-spin mode is enough.

Should be straightforward, maybe except io_iopoll_check(). We pass !min
there, because we do never enter with the number of already reaped
requests is larger than the specified @min, apart from the first
iteration, where nr_events is 0 and so the final check should be
identical.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/782b39d1d8ec584eae15bca0a1feb6f0571fe5b8.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 6878b40e7b io_uring: mark having different creds unlikely
Hint the compiler that it's not as likely to have creds different from
current attached to a request. The current code generation is far from
ideal, hopefully it can help to some compilers to remove duplicated jump
tables and so.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e7815251ac4bf5a4a23d298c752f029ae19f3837.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Hao Xu 8d4af6857c io_uring: return boolean value for io_alloc_async_data
boolean value is good enough for io_alloc_async_data.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210922101522.9179-1-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov 68fe256aad io_uring: optimise io_req_init() sqe flags checks
IOSQE_IO_DRAIN is quite marginal and we don't care too much about
IOSQE_BUFFER_SELECT. Save to ifs and hide both of them under
SQE_VALID_FLAGS check. Now we first check whether it uses a "safe"
subset, i.e. without DRAIN and BUFFER_SELECT, and only if it's not
true we test the rest of the flags.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dccfb9ab2ab0969a2d8dc59af88fa0ce44eeb1d5.1631703764.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Pavel Begunkov a3f349071e io_uring: remove ctx referencing from complete_post
Now completions are done from task context, that means that it's either
the task itself, task_work or io-wq worker. In all those cases the ctx
will be staying alive by mutexing, explicit referencing or req references
by iowq. Remove extra ctx pinning from io_req_complete_post().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/60a0e96434c16ab4fe587651448290d61ec9a113.1631703756.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:53 -06:00
Hao Xu 83f84356bc io_uring: add more uring info to fdinfo for debug
Developers may need some uring info to help themselves debug and address
issues in production. This includes sqring/cqring head/tail and the
detailed sqe/cqe info, which is very useful when an application is hung
on a ring.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210913130854.38542-1-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:52 -06:00
Pavel Begunkov d97ec6239a io_uring: kill extra wake_up_process in tw add
TWA_SIGNAL already wakes the thread, no need in wake_up_process() after
it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7e90cf643f633e857443e0c9e72471b221735c50.1631115443.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:52 -06:00
Pavel Begunkov c450178d9b io_uring: dedup CQE flushing non-empty checks
We don't do io_submit_flush_completions() when there is no requests
enqueued, and every single caller checks for it. Hide that check into
the function not forgetting about inlining. That will make it much
easier for changing the empty check condition in the future.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d7ff8cef5da1b38e8ea648f5aad9a315ddfc7b57.1631115443.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:52 -06:00
Pavel Begunkov d81499bfcd io_uring: inline linked part of io_req_find_next
Inline part of __io_req_find_next() that returns a request but doesn't
need io_disarm_next(). It's just two places, but makes links a bit
faster.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4126d13f23d0e91b39b3558e16bd86cafa7fcef2.1631115443.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:52 -06:00
Pavel Begunkov 6b639522f6 io_uring: inline io_dismantle_req
io_dismantle_req() is hot, and not _too_ huge. Inline it, there are 3
call sites, which hopefully will turn into 2 in the future.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bdd2dc30716cac270c2403e99bccd6286e4ae201.1631115443.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:52 -06:00
Pavel Begunkov 4b628aeb69 io_uring: kill off ios_left
->ios_left is only used to decide whether to plug or not, kill it to
avoid this extra accounting, just use the initial submission number.
There is no much difference in regards of enabling plugging, where this
one does it in a few more cases, but all major ones should be covered
well.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f13993bcf5b477f9a7d52881fc49f9457ea9870a.1631115443.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:52 -06:00
Jens Axboe a87acfde94 io_uring: dump sqe contents if issue fails
I recently had to look at a production problem where a request ended
up getting the dreaded -EINVAL error on submit. The most used and
hence useless of error codes, as it just tells you that something
was wrong with your request, but not more than that.

Let's dump the full sqe contents if we run into an issue failure,
that'll allow easier diagnosing of a wide variety of issues.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19 05:49:52 -06:00
Jens Axboe b688f11e86 io_uring: utilize the io batching infrastructure for more efficient polled IO
Wire up using an io_comp_batch for f_op->iopoll(). If the lower stack
supports it, we can handle high rates of polled IO more efficiently.

This raises the single core efficiency on my system from ~6.1M IOPS to
~6.6M IOPS running a random read workload at depth 128 on two gen2
Optane drives.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 14:40:46 -06:00
Jens Axboe 5a72e899ce block: add a struct io_comp_batch argument to fops->iopoll()
struct io_comp_batch contains a list head and a completion handler, which
will allow completions to more effciently completed batches of IO.

For now, no functional changes in this patch, we just define the
io_comp_batch structure and add the argument to the file_operations iopoll
handler.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 14:40:40 -06:00
Christoph Hellwig d729cf9acb io_uring: don't sleep when polling for I/O
There is no point in sleeping for the expected I/O completion timeout
in the io_uring async polling model as we never poll for a specific
I/O.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 06:17:36 -06:00
Christoph Hellwig ef99b2d376 block: replace the spin argument to blk_iopoll with a flags argument
Switch the boolean spin argument to blk_poll to passing a set of flags
instead.  This will allow to control polling behavior in a more fine
grained way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-10-hch@lst.de
[axboe: adapt to changed io_uring iopoll]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 06:17:36 -06:00
Christoph Hellwig 30da1b45b1 io_uring: fix a layering violation in io_iopoll_req_issued
syscall-level code can't just poke into the details of the poll cookie,
which is private information of the block layer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211012111226.760968-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 06:17:35 -06:00
Hao Xu 14cfbb7a78 io_uring: fix wrong condition to grab uring lock
Grab uring lock when we are in io-worker rather than in the original
or system-wq context since we already hold it in these two situation.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Fixes: b66ceaf324 ("io_uring: move iopoll reissue into regular IO path")
Link: https://lore.kernel.org/r/20211014140400.50235-1-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-14 09:06:11 -06:00
Pavel Begunkov 3f008385d4 io_uring: kill fasync
We have never supported fasync properly, it would only fire when there
is something polling io_uring making it useless. The original support came
in through the initial io_uring merge for 5.1. Since it's broken and
nobody has reported it, get rid of the fasync bits.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2f7ca3d344d406d34fa6713824198915c41cea86.1633080236.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-01 11:16:02 -06:00
Matthew Wilcox (Oracle) ffdc8dabf2 mm/filemap: Add __folio_lock_async()
There aren't any actual callers of lock_page_async(), so remove it.
Convert filemap_update_page() to call __folio_lock_async().

__folio_lock_async() is 21 bytes smaller than __lock_page_async(),
but the real savings come from using a folio in filemap_update_page(),
shrinking it from 515 bytes to 404 bytes, saving 110 bytes.  The text
shrinks by 132 bytes in total.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
2021-09-27 09:27:30 -04:00
Pavel Begunkov 7df778be2f io_uring: make OP_CLOSE consistent with direct open
From recently open/accept are now able to manipulate fixed file table,
but it's inconsistent that close can't. Close the gap, keep API same as
with open/accept, i.e. via sqe->file_slot.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 14:07:54 -06:00
Pavel Begunkov 9f3a2cb228 io_uring: kill extra checks in io_write()
We don't retry short writes and so we would never get to async setup in
io_write() in that case. Thus ret2 > 0 is always false and
iov_iter_advance() is never used. Apparently, the same is found by
Coverity, which complains on the code.

Fixes: cd65869512 ("io_uring: use iov_iter state save/restore helpers")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5b33e61034748ef1022766efc0fb8854cfcf749c.1632500058.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 10:26:11 -06:00
Jens Axboe cdb31c29d3 io_uring: don't punt files update to io-wq unconditionally
There's no reason to punt it unconditionally, we just need to ensure that
the submit lock grabbing is conditional.

Fixes: 05f3fb3c53 ("io_uring: avoid ring quiesce for fixed file set unregister and update")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 10:24:34 -06:00
Jens Axboe 9990da93d2 io_uring: put provided buffer meta data under memcg accounting
For each provided buffer, we allocate a struct io_buffer to hold the
data associated with it. As a large number of buffers can be provided,
account that data with memcg.

Fixes: ddf0322db7 ("io_uring: add IORING_OP_PROVIDE_BUFFERS")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 10:24:34 -06:00
Jens Axboe 8bab4c09f2 io_uring: allow conditional reschedule for intensive iterators
If we have a lot of threads and rings, the tctx list can get quite big.
This is especially true if we keep creating new threads and rings.
Likewise for the provided buffers list. Be nice and insert a conditional
reschedule point while iterating the nodes for deletion.

Link: https://lore.kernel.org/io-uring/00000000000064b6b405ccb41113@google.com/
Reported-by: syzbot+111d2a03f51f5ae73775@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 10:24:34 -06:00
Hao Xu 5b7aa38d86 io_uring: fix potential req refcount underflow
For multishot mode, there may be cases like:

iowq                                 original context
io_poll_add
  _arm_poll()
  mask = vfs_poll() is not 0
  if mask
(2)  io_poll_complete()
  compl_unlock
   (interruption happens
    tw queued to original
    context)
                                     io_poll_task_func()
                                     compl_lock
                                 (3) done = io_poll_complete() is true
                                     compl_unlock
                                     put req ref
(1) if (poll->flags & EPOLLONESHOT)
      put req ref

EPOLLONESHOT flag in (1) may be from (2) or (3), so there are multiple
combinations that can cause ref underfow.
Let's address it by:
- check the return value in (2) as done
- change (1) to if (done)
    in this way, we only do ref put in (1) if 'oneshot flag' is from
    (2)
- do poll.done check in io_poll_task_func(), so that we won't put ref
  for the second time.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210922101238.7177-4-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 10:24:34 -06:00
Hao Xu a62682f92e io_uring: fix missing set of EPOLLONESHOT for CQ ring overflow
We should set EPOLLONESHOT if cqring_fill_event() returns false since
io_poll_add() decides to put req or not by it.

Fixes: 5082620fb2 ("io_uring: terminate multishot poll for CQ ring overflow")
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210922101238.7177-3-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 10:24:34 -06:00
Hao Xu bd99c71bd1 io_uring: fix race between poll completion and cancel_hash insertion
If poll arming and poll completion runs in parallel, there maybe races.
For instance, run io_poll_add in iowq and io_poll_task_func in original
context, then:

  iowq                                      original context
  io_poll_add
    vfs_poll
     (interruption happens
      tw queued to original
      context)                              io_poll_task_func
                                              generate cqe
                                              del from cancel_hash[]
    if !poll.done
      insert to cancel_hash[]

The entry left in cancel_hash[], similar case for fast poll.
Fix it by set poll.done = true when del from cancel_hash[].

Fixes: 5082620fb2 ("io_uring: terminate multishot poll for CQ ring overflow")
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210922101238.7177-2-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24 10:24:34 -06:00
Paul Moore cdc1404a40 lsm,io_uring: add LSM hooks to io_uring
A full expalantion of io_uring is beyond the scope of this commit
description, but in summary it is an asynchronous I/O mechanism
which allows for I/O requests and the resulting data to be queued
in memory mapped "rings" which are shared between the kernel and
userspace.  Optionally, io_uring offers the ability for applications
to spawn kernel threads to dequeue I/O requests from the ring and
submit the requests in the kernel, helping to minimize the syscall
overhead.  Rings are accessed in userspace by memory mapping a file
descriptor provided by the io_uring_setup(2), and can be shared
between applications as one might do with any open file descriptor.
Finally, process credentials can be registered with a given ring
and any process with access to that ring can submit I/O requests
using any of the registered credentials.

While the io_uring functionality is widely recognized as offering a
vastly improved, and high performing asynchronous I/O mechanism, its
ability to allow processes to submit I/O requests with credentials
other than its own presents a challenge to LSMs.  When a process
creates a new io_uring ring the ring's credentials are inhertied
from the calling process; if this ring is shared with another
process operating with different credentials there is the potential
to bypass the LSMs security policy.  Similarly, registering
credentials with a given ring allows any process with access to that
ring to submit I/O requests with those credentials.

In an effort to allow LSMs to apply security policy to io_uring I/O
operations, this patch adds two new LSM hooks.  These hooks, in
conjunction with the LSM anonymous inode support previously
submitted, allow an LSM to apply access control policy to the
sharing of io_uring rings as well as any io_uring credential changes
requested by a process.

The new LSM hooks are described below:

 * int security_uring_override_creds(cred)
   Controls if the current task, executing an io_uring operation,
   is allowed to override it's credentials with @cred.  In cases
   where the current task is a user application, the current
   credentials will be those of the user application.  In cases
   where the current task is a kernel thread servicing io_uring
   requests the current credentials will be those of the io_uring
   ring (inherited from the process that created the ring).

 * int security_uring_sqpoll(void)
   Controls if the current task is allowed to create an io_uring
   polling thread (IORING_SETUP_SQPOLL).  Without a SQPOLL thread
   in the kernel processes must submit I/O requests via
   io_uring_enter(2) which allows us to compare any requested
   credential changes against the application making the request.
   With a SQPOLL thread, we can no longer compare requested
   credential changes against the application making the request,
   the comparison is made against the ring's credentials.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-09-19 22:37:21 -04:00
Paul Moore 91a9ab7c94 io_uring: convert io_uring to the secure anon inode interface
Converting io_uring's anonymous inode to the secure anon inode API
enables LSMs to enforce policy on the io_uring anonymous inodes if
they chose to do so.  This is an important first step towards
providing the necessary mechanisms so that LSMs can apply security
policy to io_uring operations.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-09-19 22:36:24 -04:00
Paul Moore 5bd2182d58 audit,io_uring,io-wq: add some basic audit support to io_uring
This patch adds basic auditing to io_uring operations, regardless of
their context.  This is accomplished by allocating audit_context
structures for the io-wq worker and io_uring SQPOLL kernel threads
as well as explicitly auditing the io_uring operations in
io_issue_sqe().  Individual io_uring operations can bypass auditing
through the "audit_skip" field in the struct io_op_def definition for
the operation; although great care must be taken so that security
relevant io_uring operations do not bypass auditing; please contact
the audit mailing list (see the MAINTAINERS file) with any questions.

The io_uring operations are audited using a new AUDIT_URINGOP record,
an example is shown below:

  type=UNKNOWN[1336] msg=audit(1631800225.981:37289):
    uring_op=19 success=yes exit=0 items=0 ppid=15454 pid=15681
    uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0
    subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
    key=(null)

Thanks to Richard Guy Briggs for review and feedback.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-09-19 22:10:44 -04:00
Linus Torvalds ddf21bd8ab iov_iter.3-5.15-2021-09-17
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Merge tag 'iov_iter.3-5.15-2021-09-17' of git://git.kernel.dk/linux-block

Pull io_uring iov_iter retry fixes from Jens Axboe:
 "This adds a helper to save/restore iov_iter state, and modifies
  io_uring to use it.

  After that is done, we can now kill the iter->truncated addition that
  we added for this release. The io_uring change is being overly
  cautious with the save/restore/advance, but better safe than sorry and
  we can always improve that and reduce the overhead if it proves to be
  of concern. The only case to be worried about in this regard is huge
  IO, where iteration can take a while to iterate segments.

  I spent some time writing test cases, and expanded the coverage quite
  a bit from the last posting of this. liburing carries this regression
  test case now:

      https://git.kernel.dk/cgit/liburing/tree/test/file-verify.c

  which exercises all of this. It now also supports provided buffers,
  and explicitly tests for end-of-file/device truncation as well.

  On top of that, Pavel sanitized the IOPOLL retry path to follow the
  exact same pattern as normal IO"

* tag 'iov_iter.3-5.15-2021-09-17' of git://git.kernel.dk/linux-block:
  io_uring: move iopoll reissue into regular IO path
  Revert "iov_iter: track truncated size"
  io_uring: use iov_iter state save/restore helpers
  iov_iter: add helper to save iov_iter state
2021-09-17 09:23:44 -07:00
Pavel Begunkov b66ceaf324 io_uring: move iopoll reissue into regular IO path
230d50d448 ("io_uring: move reissue into regular IO path")
made non-IOPOLL I/O to not retry from ki_complete handler. Follow it
steps and do the same for IOPOLL. Same problems, same implementation,
same -EAGAIN assumptions.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f80dfee2d5fa7678f0052a8ab3cfca9496a112ca.1631699928.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-15 09:22:35 -06:00
Jens Axboe cd65869512 io_uring: use iov_iter state save/restore helpers
Get rid of the need to do re-expand and revert on an iterator when we
encounter a short IO, or failure that warrants a retry. Use the new
state save/restore helpers instead.

We keep the iov_iter_state persistent across retries, if we need to
restart the read or write operation. If there's a pending retry, the
operation will always exit with the state correctly saved.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-15 09:22:32 -06:00
Jens Axboe 5d329e1286 io_uring: allow retry for O_NONBLOCK if async is supported
A common complaint is that using O_NONBLOCK files with io_uring can be a
bit of a pain. Be a bit nicer and allow normal retry IFF the file does
support async behavior. This makes it possible to use io_uring more
reliably with O_NONBLOCK files, for use cases where it either isn't
possible or feasible to modify the file flags.

Cc: stable@vger.kernel.org
Reported-and-tested-by: Dan Melnic <dmm@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-14 11:09:42 -06:00
Pavel Begunkov 9c7b0ba887 io_uring: auto-removal for direct open/accept
It might be inconvenient that direct open/accept deviates from the
update semantics and fails if the slot is taken instead of removing a
file sitting there. Implement this auto-removal.

Note that removal might need to allocate and so may fail. However, if an
empty slot is specified, it's guaraneed to not fail on the fd
installation side for valid userspace programs. It's needed for users
who can't tolerate such failures, e.g. accept where the other end
never retries.

Suggested-by: Franz-B. Tuneke <franz-bernhard.tuneke@tu-dortmund.de>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c896f14ea46b0eaa6c09d93149e665c2c37979b4.1631632300.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-14 09:50:56 -06:00
Xiaoguang Wang 44df58d441 io_uring: fix missing sigmask restore in io_cqring_wait()
Move get_timespec() section in io_cqring_wait() before the sigmask
saving, otherwise we'll fail to restore sigmask once get_timespec()
returns error.

Fixes: c73ebb685f ("io_uring: add timeout support for io_uring_enter()")
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210914143852.9663-1-xiaoguang.wang@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-14 08:47:00 -06:00
Jens Axboe 41d3a6bd1d io_uring: pin SQPOLL data before unlocking ring lock
We need to re-check sqd->thread after we've dropped the lock. Pin
the sqd before doing the lockdep lock dance, and check if the thread
is alive after that. It's either NULL or alive, as the SQPOLL thread
cannot exit without holding the same sqd->lock.

Reported-and-tested-by: syzbot+337de45f13a4fd54d708@syzkaller.appspotmail.com
Fixes: fa84693b3c ("io_uring: ensure IORING_REGISTER_IOWQ_MAX_WORKERS works with SQPOLL")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-13 19:44:29 -06:00
Jens Axboe 16c8d2df7e io_uring: ensure symmetry in handling iter types in loop_rw_iter()
When setting up the next segment, we check what type the iter is and
handle it accordingly. However, when incrementing and processed amount
we do not, and both iter advance and addr/len are adjusted, regardless
of type. Split the increment side just like we do on the setup side.

Fixes: 4017eb91a9 ("io_uring: make loop_rw_iter() use original user supplied pointers")
Cc: stable@vger.kernel.org
Reported-by: Valentina Palmiotti <vpalmiotti@gmail.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-12 19:27:47 -06:00
Linus Torvalds c605c39677 io_uring-5.15-2021-09-11
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Merge tag 'io_uring-5.15-2021-09-11' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:

 - Fix an off-by-one in a BUILD_BUG_ON() check. Not a real issue right
   now as we have plenty of flags left, but could become one. (Hao)

 - Fix lockdep issue introduced in this merge window (me)

 - Fix a few issues with the worker creation (me, Pavel, Qiang)

 - Fix regression with wq_has_sleeper() for IOPOLL (Pavel)

 - Timeout link error propagation fix (Pavel)

* tag 'io_uring-5.15-2021-09-11' of git://git.kernel.dk/linux-block:
  io_uring: fix off-by-one in BUILD_BUG_ON check of __REQ_F_LAST_BIT
  io_uring: fail links of cancelled timeouts
  io-wq: fix memory leak in create_io_worker()
  io-wq: fix silly logic error in io_task_work_match()
  io_uring: drop ctx->uring_lock before acquiring sqd->lock
  io_uring: fix missing mb() before waitqueue_active
  io-wq: fix cancellation on create-worker failure
2021-09-11 10:28:14 -07:00
Hao Xu 32c2d33e0b io_uring: fix off-by-one in BUILD_BUG_ON check of __REQ_F_LAST_BIT
Build check of __REQ_F_LAST_BIT should be larger than, not equal or larger
than. It's perfectly valid to have __REQ_F_LAST_BIT be 32, as that means
that the last valid bit is 31 which does fit in the type.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210907032243.114190-1-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-10 06:24:51 -06:00
Linus Torvalds 7b7699c09f Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter fixes from Al Viro:
 "Fixes for io-uring handling of iov_iter reexpands"

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  io_uring: reexpand under-reexpanded iters
  iov_iter: track truncated size
2021-09-09 12:13:46 -07:00
Pavel Begunkov 2ae2eb9dde io_uring: fail links of cancelled timeouts
When we cancel a timeout we should mark it with REQ_F_FAIL, so
linked requests are cancelled as well, but not queued for further
execution.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fff625b44eeced3a5cae79f60e6acf3fbdf8f990.1631192135.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-09 09:41:02 -06:00
Jens Axboe 009ad9f0c6 io_uring: drop ctx->uring_lock before acquiring sqd->lock
The SQPOLL thread dictates the lock order, and we hold the ctx->uring_lock
for all the registration opcodes. We also hold a ref to the ctx, and we
do drop the lock for other reasons to quiesce, so it's fine to drop the
ctx lock temporarily to grab the sqd->lock. This fixes the following
lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
5.14.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.5/25433 is trying to acquire lock:
ffff888023426870 (&sqd->lock){+.+.}-{3:3}, at: io_register_iowq_max_workers fs/io_uring.c:10551 [inline]
ffff888023426870 (&sqd->lock){+.+.}-{3:3}, at: __io_uring_register fs/io_uring.c:10757 [inline]
ffff888023426870 (&sqd->lock){+.+.}-{3:3}, at: __do_sys_io_uring_register+0x10aa/0x2e70 fs/io_uring.c:10792

but task is already holding lock:
ffff8880885b40a8 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_register+0x2e1/0x2e70 fs/io_uring.c:10791

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&ctx->uring_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:596 [inline]
       __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729
       __io_sq_thread fs/io_uring.c:7291 [inline]
       io_sq_thread+0x65a/0x1370 fs/io_uring.c:7368
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #0 (&sqd->lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3051 [inline]
       check_prevs_add kernel/locking/lockdep.c:3174 [inline]
       validate_chain kernel/locking/lockdep.c:3789 [inline]
       __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015
       lock_acquire kernel/locking/lockdep.c:5625 [inline]
       lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
       __mutex_lock_common kernel/locking/mutex.c:596 [inline]
       __mutex_lock+0x131/0x12f0 kernel/locking/mutex.c:729
       io_register_iowq_max_workers fs/io_uring.c:10551 [inline]
       __io_uring_register fs/io_uring.c:10757 [inline]
       __do_sys_io_uring_register+0x10aa/0x2e70 fs/io_uring.c:10792
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ctx->uring_lock);
                               lock(&sqd->lock);
                               lock(&ctx->uring_lock);
  lock(&sqd->lock);

 *** DEADLOCK ***

Fixes: 2e480058dd ("io-wq: provide a way to limit max number of workers")
Reported-by: syzbot+97fa56483f69d677969f@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-08 19:07:26 -06:00
Pavel Begunkov c57a91fb1c io_uring: fix missing mb() before waitqueue_active
In case of !SQPOLL, io_cqring_ev_posted_iopoll() doesn't provide a
memory barrier required by waitqueue_active(&ctx->poll_wait). There is
a wq_has_sleeper(), which does smb_mb() inside, but it's called only for
SQPOLL.

Fixes: 5fd4617840 ("io_uring: be smarter about waking multiple CQ ring waiters")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2982e53bcea2274006ed435ee2a77197107d8a29.1631130542.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-08 13:57:56 -06:00
Linus Torvalds 60f8fbaa95 for-5.15/io_uring-2021-09-04
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Merge tag 'for-5.15/io_uring-2021-09-04' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "As sometimes happens, two reports came in around the merge window open
  that led to some fixes. Hence this one is a bit bigger than usual
  followup fixes, but most of it will be going towards stable, outside
  of the fixes that are addressing regressions from this merge window.

  In detail:

   - postgres is a heavy user of signals between tasks, and if we're
     unlucky this can interfere with io-wq worker creation. Make sure
     we're resilient against unrelated signal handling. This set of
     changes also includes hardening against allocation failures, which
     could previously had led to stalls.

   - Some use cases that end up having a mix of bounded and unbounded
     work would have starvation issues related to that. Split the
     pending work lists to handle that better.

   - Completion trace int -> unsigned -> long fix

   - Fix issue with REGISTER_IOWQ_MAX_WORKERS and SQPOLL

   - Fix regression with hash wait lock in this merge window

   - Fix retry issued on block devices (Ming)

   - Fix regression with links in this merge window (Pavel)

   - Fix race with multi-shot poll and completions (Xiaoguang)

   - Ensure regular file IO doesn't inadvertently skip completion
     batching (Pavel)

   - Ensure submissions are flushed after running task_work (Pavel)"

* tag 'for-5.15/io_uring-2021-09-04' of git://git.kernel.dk/linux-block:
  io_uring: io_uring_complete() trace should take an integer
  io_uring: fix possible poll event lost in multi shot mode
  io_uring: prolong tctx_task_work() with flushing
  io_uring: don't disable kiocb_done() CQE batching
  io_uring: ensure IORING_REGISTER_IOWQ_MAX_WORKERS works with SQPOLL
  io-wq: make worker creation resilient against signals
  io-wq: get rid of FIXED worker flag
  io-wq: only exit on fatal signals
  io-wq: split bounded and unbounded work into separate lists
  io-wq: fix queue stalling race
  io_uring: don't submit half-prepared drain request
  io_uring: fix queueing half-created requests
  io-wq: ensure that hash wait lock is IRQ disabling
  io_uring: retry in case of short read on block device
  io_uring: IORING_OP_WRITE needs hash_reg_file set
  io-wq: fix race between adding work and activating a free worker
2021-09-06 09:26:07 -07:00
Pavel Begunkov 89c2b3b749 io_uring: reexpand under-reexpanded iters
[   74.211232] BUG: KASAN: stack-out-of-bounds in iov_iter_revert+0x809/0x900
[   74.212778] Read of size 8 at addr ffff888025dc78b8 by task
syz-executor.0/828
[   74.214756] CPU: 0 PID: 828 Comm: syz-executor.0 Not tainted
5.14.0-rc3-next-20210730 #1
[   74.216525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   74.219033] Call Trace:
[   74.219683]  dump_stack_lvl+0x8b/0xb3
[   74.220706]  print_address_description.constprop.0+0x1f/0x140
[   74.224226]  kasan_report.cold+0x7f/0x11b
[   74.226085]  iov_iter_revert+0x809/0x900
[   74.227960]  io_write+0x57d/0xe40
[   74.232647]  io_issue_sqe+0x4da/0x6a80
[   74.242578]  __io_queue_sqe+0x1ac/0xe60
[   74.245358]  io_submit_sqes+0x3f6e/0x76a0
[   74.248207]  __do_sys_io_uring_enter+0x90c/0x1a20
[   74.257167]  do_syscall_64+0x3b/0x90
[   74.257984]  entry_SYSCALL_64_after_hwframe+0x44/0xae

old_size = iov_iter_count();
...
iov_iter_revert(old_size - iov_iter_count());

If iov_iter_revert() is done base on the initial size as above, and the
iter is truncated and not reexpanded in the middle, it miscalculates
borders causing problems. This trace is due to no one reexpanding after
generic_write_checks().

Now iters store how many bytes has been truncated, so reexpand them to
the initial state right before reverting.

Cc: stable@vger.kernel.org
Reported-by: Palash Oswal <oswalpalash@gmail.com>
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Reported-and-tested-by: syzbot+9671693590ef5aad8953@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-09-03 19:31:33 -04:00
Xiaoguang Wang 31efe48eb5 io_uring: fix possible poll event lost in multi shot mode
IIUC, IORING_POLL_ADD_MULTI is similar to epoll's edge-triggered mode,
that means once one pure poll request returns one event(cqe), we'll
need to read or write continually until EAGAIN is returned, then I think
there is a possible poll event lost race in multi shot mode:

t1  poll request add |                         |
t2                   |                         |
t3  event happens    |                         |
t4  task work add    |                         |
t5                   | task work run           |
t6                   |   commit one cqe        |
t7                   |                         | user app handles cqe
t8                   |   new event happen      |
t9                   |   add back to waitqueue |
t10                  |

After t6 but before t9, if new event happens, there'll be no wakeup
operation, and if user app has picked up this cqe in t7, read or write
until EAGAIN is returned. In t8, new event happens and will be lost,
though this race window maybe small.

To fix this possible race, add poll request back to waitqueue before
committing cqe.

Fixes: 88e41cf928 ("io_uring: add multishot mode for IORING_OP_POLL_ADD")
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210903142436.5767-1-xiaoguang.wang@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-03 08:27:49 -06:00
Pavel Begunkov 8d4ad41e3e io_uring: prolong tctx_task_work() with flushing
io_submit_flush_completions() may enqueue linked requests for task_work
execution, so don't leave tctx_task_work() right after the tw list is
exhausted, but try to flush and then retry.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0755d4c2c36301447c63bdd4146c10477cea4249.1630539342.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-03 06:16:15 -06:00
Pavel Begunkov 636378535a io_uring: don't disable kiocb_done() CQE batching
Not passing issue_flags from kiocb_done() into __io_complete_rw() means
that completion batching for this case is disabled, e.g. for most of
buffered reads.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b2689462835c3ee28a5999ef4f9a581e24be04a2.1630539342.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-03 06:16:14 -06:00
Jens Axboe fa84693b3c io_uring: ensure IORING_REGISTER_IOWQ_MAX_WORKERS works with SQPOLL
SQPOLL has a different thread doing submissions, we need to check for
that and use the right task context when updating the worker values.
Just hold the sqd->lock across the operation, this ensures that the
thread cannot go away while we poke at ->io_uring.

Link: https://github.com/axboe/liburing/issues/420
Fixes: 2e480058dd ("io-wq: provide a way to limit max number of workers")
Reported-by: Johannes Lundberg <johalun0@gmail.com>
Tested-by: Johannes Lundberg <johalun0@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-03 06:16:11 -06:00
Pavel Begunkov b8ce1b9d25 io_uring: don't submit half-prepared drain request
[ 3784.910888] BUG: kernel NULL pointer dereference, address: 0000000000000020
[ 3784.910904] RIP: 0010:__io_file_supports_nowait+0x5/0xc0
[ 3784.910926] Call Trace:
[ 3784.910928]  ? io_read+0x17c/0x480
[ 3784.910945]  io_issue_sqe+0xcb/0x1840
[ 3784.910953]  __io_queue_sqe+0x44/0x300
[ 3784.910959]  io_req_task_submit+0x27/0x70
[ 3784.910962]  tctx_task_work+0xeb/0x1d0
[ 3784.910966]  task_work_run+0x61/0xa0
[ 3784.910968]  io_run_task_work_sig+0x53/0xa0
[ 3784.910975]  __x64_sys_io_uring_enter+0x22/0x30
[ 3784.910977]  do_syscall_64+0x3d/0x90
[ 3784.910981]  entry_SYSCALL_64_after_hwframe+0x44/0xae

io_drain_req() goes before checks for REQ_F_FAIL, which protect us from
submitting under-prepared request (e.g. failed in io_init_req(). Fail
such drained requests as well.

Fixes: a8295b982c ("io_uring: fix failed linkchain code logic")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e411eb9924d47a131b1e200b26b675df0c2b7627.1630415423.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-31 11:45:31 -06:00
Pavel Begunkov c6d3d9cbd6 io_uring: fix queueing half-created requests
[   27.259845] general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI
[   27.261043] KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
[   27.263730] RIP: 0010:sock_from_file+0x20/0x90
[   27.272444] Call Trace:
[   27.272736]  io_sendmsg+0x98/0x600
[   27.279216]  io_issue_sqe+0x498/0x68d0
[   27.281142]  __io_queue_sqe+0xab/0xb50
[   27.285830]  io_req_task_submit+0xbf/0x1b0
[   27.286306]  tctx_task_work+0x178/0xad0
[   27.288211]  task_work_run+0xe2/0x190
[   27.288571]  exit_to_user_mode_prepare+0x1a1/0x1b0
[   27.289041]  syscall_exit_to_user_mode+0x19/0x50
[   27.289521]  do_syscall_64+0x48/0x90
[   27.289871]  entry_SYSCALL_64_after_hwframe+0x44/0xae

io_req_complete_failed() -> io_req_complete_post() ->
io_req_task_queue() still would try to enqueue hard linked request,
which can be half prepared (e.g. failed init), so we can't allow
that to happen.

Fixes: a8295b982c ("io_uring: fix failed linkchain code logic")
Reported-by: syzbot+f9704d1878e290eddf73@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/70b513848c1000f88bd75965504649c6bb1415c0.1630415423.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-31 11:45:31 -06:00
Ming Lei 7db304375e io_uring: retry in case of short read on block device
In case of buffered reading from block device, when short read happens,
we should retry to read more, otherwise the IO will be completed
partially, for example, the following fio expects to read 2MB, but it
can only read 1M or less bytes:

    fio --name=onessd --filename=/dev/nvme0n1 --filesize=2M \
	--rw=randread --bs=2M --direct=0 --overwrite=0 --numjobs=1 \
	--iodepth=1 --time_based=0 --runtime=2 --ioengine=io_uring \
	--registerfiles --fixedbufs --gtod_reduce=1 --group_reporting

Fix the issue by allowing short read retry for block device, which sets
FMODE_BUF_RASYNC really.

Fixes: 9a173346bd ("io_uring: fix short read retries for non-reg files")
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20210821150751.1290434-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-31 11:45:30 -06:00
Jens Axboe 7b3188e7ed io_uring: IORING_OP_WRITE needs hash_reg_file set
During some testing, it became evident that using IORING_OP_WRITE doesn't
hash buffered writes like the other writes commands do. That's simply
an oversight, and can cause performance regressions when doing buffered
writes with this command.

Correct that and add the flag, so that buffered writes are correctly
hashed when using the non-iovec based write command.

Cc: stable@vger.kernel.org
Fixes: 3a6820f2bb ("io_uring: add non-vectored read/write commands")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-31 11:45:30 -06:00
Linus Torvalds b91db6a0b5 for-5.15/io_uring-vfs-2021-08-30
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Merge tag 'for-5.15/io_uring-vfs-2021-08-30' of git://git.kernel.dk/linux-block

Pull io_uring mkdirat/symlinkat/linkat support from Jens Axboe:
 "This adds io_uring support for mkdirat, symlinkat, and linkat"

* tag 'for-5.15/io_uring-vfs-2021-08-30' of git://git.kernel.dk/linux-block:
  io_uring: add support for IORING_OP_LINKAT
  io_uring: add support for IORING_OP_SYMLINKAT
  io_uring: add support for IORING_OP_MKDIRAT
  namei: update do_*() helpers to return ints
  namei: make do_linkat() take struct filename
  namei: add getname_uflags()
  namei: make do_symlinkat() take struct filename
  namei: make do_mknodat() take struct filename
  namei: make do_mkdirat() take struct filename
  namei: change filename_parentat() calling conventions
  namei: ignore ERR/NULL names in putname()
2021-08-30 19:39:59 -07:00
Linus Torvalds 3b629f8d6d io_uring-bio-cache.5-2021-08-30
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Merge tag 'io_uring-bio-cache.5-2021-08-30' of git://git.kernel.dk/linux-block

Pull support for struct bio recycling from Jens Axboe:
 "This adds bio recycling support for polled IO, allowing quick reuse of
  a bio for high IOPS scenarios via a percpu bio_set list.

  It's good for almost a 10% improvement in performance, bumping our
  per-core IO limit from ~3.2M IOPS to ~3.5M IOPS"

* tag 'io_uring-bio-cache.5-2021-08-30' of git://git.kernel.dk/linux-block:
  bio: improve kerneldoc documentation for bio_alloc_kiocb()
  block: provide bio_clear_hipri() helper
  block: use the percpu bio cache in __blkdev_direct_IO
  io_uring: enable use of bio alloc cache
  block: clear BIO_PERCPU_CACHE flag if polling isn't supported
  bio: add allocation cache abstraction
  fs: add kiocb alloc cache flag
  bio: optimize initialization of a bio
2021-08-30 19:30:30 -07:00