1314 Commits

Author SHA1 Message Date
Pavel Begunkov
e4335ed33e io_uring: improve hardlink code generation
req_set_fail_links() condition checking is bulky. Even though it's
always in a slow path, it's inlined and generates lots of extra code,
simplify it be moving HARDLINK checking into helpers killing linked
requests.

          text    data     bss     dec     hex filename
before:  79318   12330       8   91656   16608 ./fs/io_uring.o
after:   79126   12330       8   91464   16548 ./fs/io_uring.o

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/96a9387db658a9d5a44ecbfd57c2a62cb888c9b6.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-12 09:33:07 -06:00
Pavel Begunkov
88885f66e8 io_uring: improve sqo stop
Set IO_SQ_THREAD_SHOULD_STOP before taking sqd lock, so the sqpoll task
sees earlier. Not a problem, it will stop eventually. Also check
invariant that it's stopped only once.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/653b24ee93843a50ff65a45847d9138f5adb76d7.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-12 09:33:04 -06:00
Pavel Begunkov
aeca241b0b io_uring: split file table from rsrc nodes
We don't need to store file tables in rsrc nodes, for now it's easier to
handle tables not generically, so move file tables into the context. A
nice side effect is having one less pointer dereference for request with
fixed file initialisation.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/de9fc4cd3545f24c26c03be4556f58ba3d18b9c3.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-12 09:33:01 -06:00
Pavel Begunkov
87094465d0 io_uring: cleanup buffer register
In preparation for more changes do a little cleanup of
io_sqe_buffers_register(). Move all args/invariant checking into it from
io_buffers_map_alloc(), because it's confusing. And add a bit more
cleaning for the loop.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/93292cb9708c8455e5070cc855861d94e11ca042.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-12 09:32:58 -06:00
Pavel Begunkov
7f61a1e9ef io_uring: add buffer unmap helper
Add a helper for unmapping registered buffers, better than double
indexing and will be reused in the future.

Suggested-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/66cbc6ea863be865bac7b7080ed6a3d5c542b71f.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-12 09:32:55 -06:00
Pavel Begunkov
3e9424989b io_uring: simplify io_rsrc_data refcounting
We don't take many references of struct io_rsrc_data, only one per each
io_rsrc_node, so using percpu refs is overkill. Use atomic ref instead,
which is much simpler.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1551d90f7c9b183cf2f0d7b5e5b923430acb03fa.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-12 09:32:47 -06:00
Jens Axboe
a1ff1e3f0e io_uring: provide io_resubmit_prep() stub for !CONFIG_BLOCK
Randy reports the following error on CONFIG_BLOCK not being set:

../fs/io_uring.c: In function ‘kiocb_done’:
../fs/io_uring.c:2766:7: error: implicit declaration of function ‘io_resubmit_prep’; did you mean ‘io_put_req’? [-Werror=implicit-function-declaration]
   if (io_resubmit_prep(req)) {

Provide a dummy stub for io_resubmit_prep() like we do for
io_rw_should_reissue(), which also helps remove an ifdef sequence from
io_complete_rw_iopoll() as well.

Fixes: 8c130827f417 ("io_uring: don't alter iopoll reissue fail ret code")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-12 06:40:02 -06:00
Pavel Begunkov
8d13326e56 io_uring: optimise fill_event() by inlining
There are three cases where we much care about performance of
io_cqring_fill_event() -- flushing inline completions, iopoll and
io_req_complete_post(). Inline a hot part of fill_event() into them.

All others are not as important and we don't want to bloat binary for
them, so add a noinline version of the function for all other use
use cases.

nops test(batch=32): 16.932 vs 17.822 KIOPS

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a11d59424bf4417aca33f5ec21008bb3b0ebd11e.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:41 -06:00
Pavel Begunkov
ff64216423 io_uring: always pass cflags into fill_event()
A simple preparation patch inlining io_cqring_fill_event(), which only
role was to pass cflags=0 into an actual fill event. It helps to keep
number of related helpers sane in following patches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/704f9c85b7d9843e4ad50a9f057200c58f5adc6e.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:41 -06:00
Pavel Begunkov
44c769de6f io_uring: optimise non-eventfd post-event
Eventfd is not the canonical way of using io_uring, annotate
io_should_trigger_evfd() with likely so it improves code generation for
non-eventfd branch.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/42fdaa51c68d39479f02cef4fe5bcb24624d60fa.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:41 -06:00
Pavel Begunkov
4af3417a34 io_uring: refactor compat_msghdr import
Add an entry for user pointer to compat_msghdr into io_connect, so it's
explicit that we may use it as this, and removes annoying casts.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/73fd644dea1518f528d3648981cf777ce6e537e9.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:41 -06:00
Pavel Begunkov
0bdf3398b0 io_uring: enable inline completion for more cases
Take advantage of delayed/inline completion flushing and pass right
issue flags for completion of open, open2, fadvise and poll remove
opcodes. All others either already use it or always punted and never
executed inline.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0badc7512e82f7350b73bb09abbebbecbdd5dab8.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:41 -06:00
Pavel Begunkov
a1fde923e3 io_uring: refactor io_close
A small refactoring shrinking it and making easier to read.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/19b24eed7cd491a0243b50366dd2a23b558e2665.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:41 -06:00
Pavel Begunkov
3f48cf18f8 io_uring: unify files and task cancel
Now __io_uring_cancel() and __io_uring_files_cancel() are very similar
and mostly differ by how we count requests, merge them and allow
tctx_inflight() to handle counting.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1a5986a97df4dc1378f3fe0ca1eb483dbcf42112.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:41 -06:00
Pavel Begunkov
b303fe2e5a io_uring: track inflight requests through counter
Instead of keeping requests in a inflight_list, just track them with a
per tctx atomic counter. Apart from it being much easier and more
consistent with task cancel, it frees ->inflight_entry from being shared
between iopoll and cancel-track, so less headache for us.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3c2ee0863cd7eeefa605f3eaff4c1c461a6f1157.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:41 -06:00
Pavel Begunkov
368b208085 io_uring: unify task and files cancel loops
Move tracked inflight number check up the stack into
__io_uring_files_cancel() so it's similar to task cancel. Will be used
for further cleaning.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dca5a395efebd1e3e0f3bbc6b9640c5e8aa7e468.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:40 -06:00
Pavel Begunkov
0ea13b448e io_uring: simplify apoll hash removal
hash_del() works well with non-hashed nodes, there's no need to check
if it is hashed first.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:40 -06:00
Pavel Begunkov
e27414bef7 io_uring: refactor io_poll_complete()
Remove error parameter from io_poll_complete(), 0 is always passed,
and do a bit of cleaning on top.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:40 -06:00
Pavel Begunkov
f40b964a66 io_uring: clean up io_poll_task_func()
io_poll_complete() always fills an event (even an overflowed one), so we
always should do io_cqring_ev_posted() afterwards. And that's what is
currently happening, because second EPOLLONESHOT check is always true,
it can't return !done for oneshots.

Remove those branching, it's much easier to read.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:40 -06:00
Jens Axboe
cb3b200e4f io_uring: don't attempt re-add of multishot poll request if racing
We currently allow racy updates to multishot requests, but we can end up
double adding the poll request if both completion and update does it.
Ensure that we skip re-add on the update side if someone else is
completing it.

Fixes: b69de288e913 ("io_uring: allow events and user_data update of running poll requests")
Reported-by: Joakim Hassila <joj@mac.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:35 -06:00
Pavel Begunkov
53a3126756 io_uring: kill outdated comment about splice punt
The splice/tee comment in io_prep_async_work() isn't relevant since the
section was moved, delete it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/892a549c89c3d422b679677b8e68ffd3fcb736b6.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:35 -06:00
Pavel Begunkov
a04b0ac0cb io_uring: encapsulate fixed files into struct
Add struct io_fixed_file representing a single registered file, first to
hide ugly struct file **, which may be misleading, and secondly to
retype it to unsigned long as conversions to it and back to file * for
handling and masking FFS_* flags are getting nasty.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/78669731a605a7614c577c3de552631cfaf0869a.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:35 -06:00
Pavel Begunkov
846a4ef22b io_uring: refactor file tables alloc/free
Introduce a heler io_free_file_tables() doing all the cleaning, there
are several places where it's hand coded. Also move all allocations into
io_sqe_alloc_file_tables() and rename it, so all of it is in one place.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/502a84ebf41ff119b095e59661e678eacb752bf8.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:35 -06:00
Pavel Begunkov
f4f7d21ce4 io_uring: don't quiesce intial files register
There is no reason why we would want to fully quiesce ring on
IORING_REGISTER_FILES, if it's already registered we fail.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/563bb8060bb2d3efbc32fce6101678281c574d2a.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:35 -06:00
Pavel Begunkov
9a321c9849 io_uring: set proper FFS* flags on reg file update
Set FFS_* flags (e.g. FFS_ASYNC_READ) not only in initial registration
but also on registered files update. Not a bug, but may miss getting
profit out of the feature.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/df29a841a2d3d3695b509cdffce5070777d9d942.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:35 -06:00
Pavel Begunkov
044118069a io_uring: deduplicate NOSIGNAL setting
Set MSG_NOSIGNAL and REQ_F_NOWAIT in send/recv prep routines and don't
duplicate it in all four send/recv handlers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e1133a3ed1c0e192975b7341ea4b0bf91f63b132.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:35 -06:00
Pavel Begunkov
df9727affa io_uring: put link timeout req consistently
Don't put linked timeout req in io_async_find_and_cancel() but do it in
io_link_timeout_fn(), so we have only one point for that and won't have
to do it differently as it's now (put vs put_deferred). Btw, improve a
bit io_async_find_and_cancel()'s locking.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d75b70957f245275ab7cba83e0ac9c1b86aae78a.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
c4ea060e85 io_uring: simplify overflow handling
Overflowed CQEs doesn't lock requests anymore, so we don't care so much
about cancelling them, so kill cq_overflow_flushed and simplify the
code.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5799867aeba9e713c32f49aef78e5e1aef9fbc43.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
e07785b002 io_uring: lock annotate timeouts and poll
Add timeout and poll ->comletion_lock annotations for Sparse, makes life
easier while looking at the functions.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2345325643093d41543383ba985a735aeb899eac.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
47e90392c8 io_uring: kill unused forward decls
Kill unused forward declarations for io_ring_file_put() and
io_queue_next(). Also btw rename the first one.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/64aa27c3f9662e14615cc119189f5eaf12989671.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
4751f53d74 io_uring: store reg buffer end instead of length
It's a bit more convenient for us to store a registered buffer end
address instead of length, see struct io_mapped_ubuf, as it allow to not
recompute it every time.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/39164403fe92f1dc437af134adeec2423cdf9395.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
75769e3f73 io_uring: improve import_fixed overflow checks
Replace a hand-coded overflow check with a specialised function. Even
though compilers are smart enough to generate identical binary (i.e.
check carry bit), but it's more foolproof and conveys the intention
better.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e437dcdc929bacbb6f11a4824ecbbf17225cb82a.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
0aec38fda2 io_uring: refactor io_async_cancel()
Remove extra tctx==NULL checks that are already done by
io_async_cancel_one().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/70c2a8b958d942e86958a28af0452966ce1095b0.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
e146a4a3f6 io_uring: remove unused hash_wait
No users of io_uring_ctx::hash_wait left, kill it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e25cb83c233a5f75f15275596b49fbafbea606fa.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
7394161cb8 io_uring: better ref handling in poll_remove_one
Instead of io_put_req() to drop not a final ref, use req_ref_put(),
which is slimmer and will also check the invariant.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/85b5774ce13ae55cc2e705abdc8cbafe1212f1bd.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
89b5066ea1 io_uring: combine lock/unlock sections on exit
io_ring_exit_work() already does uring_lock lock/unlock, no need to
repeat it for lock waiting trick in io_ring_ctx_free(). Move the waiting
with comments and spinlocking into io_ring_exit_work.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a8ae0589b0ea64ad4791e2c282e4e9b713dd7024.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
215c390260 io_uring: remove useless is_dying check on quiesce
rsrc_data refs should always be valid for potential submitters,
io_rsrc_ref_quiesce() restores it before unlocking, so
percpu_ref_is_dying() check in io_sqe_files_unregister() does nothing
and misleading. Concurrent quiesce is prevented with
struct io_rsrc_data::quiesce.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bf97055e1748ee3a382e66daf384a469eb90b931.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
28a9fe2521 io_uring: reuse io_rsrc_node_destroy()
Reuse io_rsrc_node_destroy() in __io_rsrc_put_work(). Also move it to a
more appropriate place -- to the other node routines, and remove forward
declaration.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/cccafba41aee1e5bb59988704885b1340aef3a27.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
a7f0ed5acd io_uring: ctx-wide rsrc nodes
If we're going to ever support multiple types of resources we need
shared rsrc nodes to not bloat requests, that is implemented in this
patch. It also gives a nicer API and saves one pointer dereference
in io_req_set_rsrc_node().

We may say that all requests bound to a resource belong to one and only
one rsrc node, and considering that nodes are removed and recycled
strictly in-order, this separates requests into generations, where
generation are changed on each node switch (i.e. io_rsrc_node_switch()).

The API is simple, io_rsrc_node_switch() switches to a new generation if
needed, and also optionally kills a passed in io_rsrc_data. Each call to
io_rsrc_node_switch() have to be preceded with
io_rsrc_node_switch_start(). The start function is idempotent and should
not necessarily be followed by switch.

One difference is that once a node was set it will always retain a valid
rsrc node, even on unregister. It may be a nuisance at the moment, but
makes much sense for multiple types of resources. Another thing changed
is that nodes are bound to/associated with a io_rsrc_data later just
before killing (i.e. switching).

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7e9c693b4b9a2f47aa784b616ce29843021bb65a.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
e7c78371bb io_uring: refactor io_queue_rsrc_removal()
Pass rsrc_node into io_queue_rsrc_removal() explicitly. Just a
simple preparation patch, makes following changes nicer.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/002889ce4de7baf287f2b010eef86ffe889174c6.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
40ae0ff70f io_uring: move rsrc_put callback into io_rsrc_data
io_rsrc_node's callback operates only on a single io_rsrc_data and only
with its resources, so rsrc_put() callback is actually a property of
io_rsrc_data. Move it there, it makes code much nicecr.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9417c2fba3c09e8668f05747006a603d416d34b4.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
82fbcfa996 io_uring: encapsulate rsrc node manipulations
io_rsrc_node_get() and io_rsrc_node_set() are always used together,
merge them into one so most users don't even see io_rsrc_node and don't
need to care about it.

It helped to catch io_sqe_files_register() inferring rsrc data argument
for get and set differently, not a problem but a good sign.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0827b080b2e61b3dec795380f7e1a1995595d41f.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
f3baed3992 io_uring: use rsrc prealloc infra for files reg
Keep it consistent with update and use io_rsrc_node_prealloc() +
io_rsrc_node_get() in io_sqe_files_register() as well, that will be used
in future patches, not as error prone and allows to deduplicate
rsrc_node init.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/cf87321e6be5e38f4dc7fe5079d2aa6945b1ace0.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
221aa92409 io_uring: simplify io_rsrc_node_ref_zero
Replace queue_delayed_work() with mod_delayed_work() in
io_rsrc_node_ref_zero() as the later one can schedule a new work, and
cleanup it further for better readability.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3b2b23e3a1ea4bbf789cd61815d33e05d9ff945e.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Pavel Begunkov
b895c9a632 io_uring: name rsrc bits consistently
Keep resource related structs' and functions' naming consistent, in
particular use "io_rsrc" prefix for everything.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/962f5acdf810f3a62831e65da3932cde24f6d9df.1617287883.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:34 -06:00
Jens Axboe
b2e720ace2 io_uring: fix race around poll update and poll triggering
Joakim reports that in some conditions he sees a multishot poll request
being canceled, and that it coincides with getting -EALREADY on
modification. As part of the poll update procedure, there's a small window
where the request is marked as canceled, and if this coincides with the
event actually triggering, then we can get a spurious -ECANCELED and
termination of the multishot request.

Don't mark the poll request as being canceled for update. We also don't
care if we race on removal unless it's a one-shot request, we can safely
updated for either case.

Fixes: b69de288e913 ("io_uring: allow events and user_data update of running poll requests")
Reported-by: Joakim Hassila <joj@mac.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 19:30:17 -06:00
Pavel Begunkov
50e96989d7 io_uring: reg buffer overflow checks hardening
We are safe with overflows in io_sqe_buffer_register() because it will
just yield alloc failure, but it's nicer to check explicitly.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2b0625551be3d97b80a5fd21c8cd79dc1c91f0b5.1616624589.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 17:42:00 -06:00
Jens Axboe
548d819d1e io_uring: allow SQPOLL without CAP_SYS_ADMIN or CAP_SYS_NICE
Now that we have any worker being attached to the original task as
threads, accounting of CPU time is directly attributed to the original
task as well. This means that we no longer have to restrict SQPOLL to
needing elevated privileges, as it's really no different from just having
the task spawn a busy looping thread in userspace.

Reported-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 17:42:00 -06:00
Jens Axboe
685fe7feed io-wq: eliminate the need for a manager thread
io-wq relies on a manager thread to create/fork new workers, as needed.
But there's really no strong need for it anymore. We have the following
cases that fork a new worker:

1) Work queue. This is done from the task itself always, and it's trivial
   to create a worker off that path, if needed.

2) All workers have gone to sleep, and we have more work. This is called
   off the sched out path. For this case, use a task_work items to queue
   a fork-worker operation.

3) Hashed work completion. Don't think we need to do anything off this
   case. If need be, it could just use approach 2 as well.

Part of this change is incrementing the running worker count before the
fork, to avoid cases where we observe we need a worker and then queue
creation of one. Then new work comes in, we fork a new one. That last
queue operation should have waited for the previous worker to come up,
it's quite possible we don't even need it. Hence move the worker running
from before we fork it off to more efficiently handle that case.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 17:42:00 -06:00
Jens Axboe
b69de288e9 io_uring: allow events and user_data update of running poll requests
This adds two new POLL_ADD flags, IORING_POLL_UPDATE_EVENTS and
IORING_POLL_UPDATE_USER_DATA. As with the other POLL_ADD flag, these are
masked into sqe->len. If set, the POLL_ADD will have the following
behavior:

- sqe->addr must contain the the user_data of the poll request that
  needs to be modified. This field is otherwise invalid for a POLL_ADD
  command.

- If IORING_POLL_UPDATE_EVENTS is set, sqe->poll_events must contain the
  new mask for the existing poll request. There are no checks for whether
  these are identical or not, if a matching poll request is found, then it
  is re-armed with the new mask.

- If IORING_POLL_UPDATE_USER_DATA is set, sqe->off must contain the new
  user_data for the existing poll request.

A POLL_ADD with any of these flags set may complete with any of the
following results:

1) 0, which means that we successfully found the existing poll request
   specified, and performed the re-arm procedure. Any error from that
   re-arm will be exposed as a completion event for that original poll
   request, not for the update request.
2) -ENOENT, if no existing poll request was found with the given
   user_data.
3) -EALREADY, if the existing poll request was already in the process of
   being removed/canceled/completing.
4) -EACCES, if an attempt was made to modify an internal poll request
   (eg not one originally issued ass IORING_OP_POLL_ADD).

The usual -EINVAL cases apply as well, if any invalid fields are set
in the sqe for this command type.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 17:42:00 -06:00