Commit Graph

166 Commits

Author SHA1 Message Date
Keith Busch 9408d8a37e nvme: improved uring polling
Drivers can poll requests directly, so use that. We just need to ensure
the driver's request was allocated from a polled hctx, so a special
driver flag is added to struct io_uring_cmd.

The allows unshared and multipath namespaces to use the same polling
callback, and multipath is guaranteed to get the same queue as the
command was submitted on. Previously multipath polling might check a
different path and poll the wrong info.

The other bonus is we don't need a bio payload in order to poll,
allowing commands like 'flush' and 'write zeroes' to be submitted on the
same high priority queue as read and write commands.

Finally, using the request based polling skips the unnecessary bio
overhead.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230612190343.2087040-3-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-28 16:09:41 -06:00
Josh Triplett 6e76ac5958 io_uring: Add io_uring_setup flag to pre-register ring fd and never install it
With IORING_REGISTER_USE_REGISTERED_RING, an application can register
the ring fd and use it via registered index rather than installed fd.
This allows using a registered ring for everything *except* the initial
mmap.

With IORING_SETUP_NO_MMAP, io_uring_setup uses buffers allocated by the
user, rather than requiring a subsequent mmap.

The combination of the two allows a user to operate *entirely* via a
registered ring fd, making it unnecessary to ever install the fd in the
first place. So, add a flag IORING_SETUP_REGISTERED_FD_ONLY to make
io_uring_setup register the fd and return a registered index, without
installing the fd.

This allows an application to avoid touching the fd table at all, and
allows a library to never even momentarily install a file descriptor.

This splits out an io_ring_add_registered_file helper from
io_ring_add_registered_fd, for use by io_uring_setup.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Link: https://lore.kernel.org/r/bc8f431bada371c183b95a83399628b605e978a3.1682699803.git.josh@joshtriplett.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-16 08:06:00 -06:00
Jens Axboe 03d89a2de2 io_uring: support for user allocated memory for rings/sqes
Currently io_uring applications must call mmap(2) twice to map the rings
themselves, and the sqes array. This works fine, but it does not support
using huge pages to back the rings/sqes.

Provide a way for the application to pass in pre-allocated memory for
the rings/sqes, which can then suitably be allocated from shmfs or
via mmap to get huge page support.

Particularly for larger rings, this reduces the TLBs needed.

If an application wishes to take advantage of that, it must pre-allocate
the memory needed for the sq/cq ring, and the sqes. The former must
be passed in via the io_uring_params->cq_off.user_data field, while the
latter is passed in via the io_uring_params->sq_off.user_data field. Then
it must set IORING_SETUP_NO_MMAP in the io_uring_params->flags field,
and io_uring will then map the existing memory into the kernel for shared
use. The application must not call mmap(2) to map rings as it otherwise
would have, that will now fail with -EINVAL if this setup flag was used.

The pages used for the rings and sqes must be contigious. The intent here
is clearly that huge pages should be used, otherwise the normal setup
procedure works fine as-is. The application may use one huge page for
both the rings and sqes.

Outside of those initialization changes, everything works like it did
before.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-16 08:04:55 -06:00
David Wei ea97f6c855 io_uring: add support for multishot timeouts
A multishot timeout submission will repeatedly generate completions with
the IORING_CQE_F_MORE cflag set. Depending on the value of the `off'
field in the submission, these timeouts can either repeat indefinitely
until cancelled (`off' = 0) or for a fixed number of times (`off' > 0).

Only noseq timeouts (i.e. not dependent on the number of I/O
completions) are supported.

An indefinite timer will be cancelled if the CQ ever overflows.

Signed-off-by: David Wei <davidhwei@meta.com>
Link: https://lore.kernel.org/r/20230418225817.1905027-1-davidhwei@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-18 19:38:36 -06:00
Pavel Begunkov d322818ef4 io_uring: kill unused notif declarations
There are two leftover structures from the notification registration
mechanism that has never been released, kill them.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f05f65aebaf8b1b5bf28519a8fdb350e3e7c9ad0.1679924536.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:16:15 -06:00
Jens Axboe c56e022c0a io_uring: add support for user mapped provided buffer ring
The ring mapped provided buffer rings rely on the application allocating
the memory for the ring, and then the kernel will map it. This generally
works fine, but runs into issues on some architectures where we need
to be able to ensure that the kernel and application virtual address for
the ring play nicely together. This at least impacts architectures that
set SHM_COLOUR, but potentially also anyone setting SHMLBA.

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

	IORING_OFF_PBUF_RING | (bgid << IORING_OFF_PBUF_SHIFT)

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

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

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

Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:21 -06:00
Linus Torvalds 4a7d37e824 hardening updates for v6.3-rc1
- Replace 0-length and 1-element arrays with flexible arrays in various
   subsystems (Paulo Miguel Almeida, Stephen Rothwell, Kees Cook)
 
 - randstruct: Disable Clang 15 support (Eric Biggers)
 
 - GCC plugins: Drop -std=gnu++11 flag (Sam James)
 
 - strpbrk(): Refactor to use strchr() (Andy Shevchenko)
 
 - LoadPin LSM: Allow root filesystem switching when non-enforcing
 
 - fortify: Use dynamic object size hints when available
 
 - ext4: Fix CFI function prototype mismatch
 
 - Nouveau: Fix DP buffer size arguments
 
 - hisilicon: Wipe entire crypto DMA pool on error
 
 - coda: Fully allocate sig_inputArgs
 
 - UBSAN: Improve arm64 trap code reporting
 
 - copy_struct_from_user(): Add minimum bounds check on kernel buffer size
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmPv1Y8WHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJg5UD/9x3Lx0EG3iL4qPtjmohaXd899r
 AzP1ysoxYnmo/cY0//W3DPCJrUaVlTm7M2xXOpzi7YPVD8Jcofzy6Uxm9BiG/OJ9
 bla7uQixlDMA2MBmWzAXhM7337WgEtBcr6kbXk6rHFnzmk8CdAY3wjmLmiefxEWT
 gkdeJlbkBFynssSF2nejgCvr/ZyiWQr2V9hRdEavLQH/MDS785bmNwbLyUNqK+eo
 gOtuyjyV90t+cSIN0bF7gOCFGf1ivKA/+GNFrob0jY0Fy2kGx1I2wQMn9yzjzerC
 o6Majz9r+7Z7xIaz2Pm9nDaWyZDI05RfoRpQZ9dSEJ+zYgbFBFpDpJShcJvSpNa0
 POqeR400n/6VWBcbk7UU0s7VCVU13IsOFhBSVMQM5FfzIcUkj0/VBm0Jm0ODrpM9
 13/nKyAkvHkH0uSJbQjn79rXvEvqQyi5f28emm2CuhiHHUiDEUdsmMD7fE8UXo4r
 U8dgfwTOLLQBKmOQJcgiLo8iLDPhatZKYQAZ7LMY9kbHLsJlRVxfzY9PriNCuI5o
 XuMLJG33TrlUDfqQrKeSJ9srVRiiIBAzoWnIfIVE3Xb46LqFNXVRdJCt4A2678jn
 gYIzkQ2HbVe2chUhUyjsjGTjmmeX9qZG0UOlhRQ0RvWFxi390wwYqhkSaOEGtDGv
 QbVh0Lb86m3H/G+M9g==
 =XnVa
 -----END PGP SIGNATURE-----

Merge tag 'hardening-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:
 "Beyond some specific LoadPin, UBSAN, and fortify features, there are
  other fixes scattered around in various subsystems where maintainers
  were okay with me carrying them in my tree or were non-responsive but
  the patches were reviewed by others:

   - Replace 0-length and 1-element arrays with flexible arrays in
     various subsystems (Paulo Miguel Almeida, Stephen Rothwell, Kees
     Cook)

   - randstruct: Disable Clang 15 support (Eric Biggers)

   - GCC plugins: Drop -std=gnu++11 flag (Sam James)

   - strpbrk(): Refactor to use strchr() (Andy Shevchenko)

   - LoadPin LSM: Allow root filesystem switching when non-enforcing

   - fortify: Use dynamic object size hints when available

   - ext4: Fix CFI function prototype mismatch

   - Nouveau: Fix DP buffer size arguments

   - hisilicon: Wipe entire crypto DMA pool on error

   - coda: Fully allocate sig_inputArgs

   - UBSAN: Improve arm64 trap code reporting

   - copy_struct_from_user(): Add minimum bounds check on kernel buffer
     size"

* tag 'hardening-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  randstruct: disable Clang 15 support
  uaccess: Add minimum bounds check on kernel buffer size
  arm64: Support Clang UBSAN trap codes for better reporting
  coda: Avoid partial allocation of sig_inputArgs
  gcc-plugins: drop -std=gnu++11 to fix GCC 13 build
  lib/string: Use strchr() in strpbrk()
  crypto: hisilicon: Wipe entire pool on error
  net/i40e: Replace 0-length array with flexible array
  io_uring: Replace 0-length array with flexible array
  ext4: Fix function prototype mismatch for ext4_feat_ktype
  i915/gvt: Replace one-element array with flexible-array member
  drm/nouveau/disp: Fix nvif_outp_acquire_dp() argument size
  LoadPin: Allow filesystem switch when not enforcing
  LoadPin: Move pin reporting cleanly out of locking
  LoadPin: Refactor sysctl initialization
  LoadPin: Refactor read-only check into a helper
  ARM: ixp4xx: Replace 0-length arrays with flexible arrays
  fortify: Use __builtin_dynamic_object_size() when available
  rxrpc: replace zero-lenth array with DECLARE_FLEX_ARRAY() helper
2023-02-21 11:07:23 -08:00
Josh Triplett 7d3fd88d61 io_uring: Support calling io_uring_register with a registered ring fd
Add a new flag IORING_REGISTER_USE_REGISTERED_RING (set via the high bit
of the opcode) to treat the fd as a registered index rather than a file
descriptor.

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

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Link: https://lore.kernel.org/r/f2396369e638284586b069dbddffb8c992afba95.1676419314.git.josh@joshtriplett.org
[axboe: remove extra high bit clear]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-16 06:09:30 -07:00
Breno Leitao cbeb47a7b5 io_uring/msg_ring: Pass custom flags to the cqe
This patch adds a new flag (IORING_MSG_RING_FLAGS_PASS) in the message
ring operations (IORING_OP_MSG_RING). This new flag enables the sender
to specify custom flags, which will be copied over to cqe->flags in the
receiving ring.  These custom flags should be specified using the
sqe->file_index field.

This mechanism provides additional flexibility when sending messages
between rings.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230103160507.617416-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:40 -07:00
Kees Cook 36632d0629 io_uring: Replace 0-length array with flexible array
Zero-length arrays are deprecated[1]. Replace struct io_uring_buf_ring's
"bufs" with a flexible array member. (How is the size of this array
verified?) Detected with GCC 13, using -fstrict-flex-arrays=3:

In function 'io_ring_buffer_select',
    inlined from 'io_buffer_select' at io_uring/kbuf.c:183:10:
io_uring/kbuf.c:141:23: warning: array subscript 255 is outside the bounds of an interior zero-length array 'struct io_uring_buf[0]' [-Wzero-length-bounds]
  141 |                 buf = &br->bufs[head];
      |                       ^~~~~~~~~~~~~~~
In file included from include/linux/io_uring.h:7,
                 from io_uring/kbuf.c:10:
include/uapi/linux/io_uring.h: In function 'io_buffer_select':
include/uapi/linux/io_uring.h:628:41: note: while referencing 'bufs'
  628 |                 struct io_uring_buf     bufs[0];
      |                                         ^~~~

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Fixes: c7fb19428d ("io_uring: add support for ring mapped supplied buffers")
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: stable@vger.kernel.org
Cc: io-uring@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230105190507.gonna.131-kees@kernel.org
2023-01-27 11:42:57 -08:00
Stefan Metzmacher 9eb803402a uapi:io_uring.h: allow linux/time_types.h to be skipped
include/uapi/linux/io_uring.h is synced 1:1 into
liburing:src/include/liburing/io_uring.h.

liburing has a configure check to detect the need for
linux/time_types.h. It can opt-out by defining
UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H

Fixes: 78a861b949 ("io_uring: add sync cancelation API through io_uring_register()")
Link: https://github.com/axboe/liburing/issues/708
Link: https://github.com/axboe/liburing/pull/709
Link: https://lore.kernel.org/io-uring/20221115212614.1308132-1-ammar.faizi@intel.com/T/#m9f5dd571cd4f6a5dee84452dbbca3b92ba7a4091
CC: Jens Axboe <axboe@kernel.dk>
Cc: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Link: https://lore.kernel.org/r/7071a0a1d751221538b20b63f9160094fc7e06f4.1668630247.git.metze@samba.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-27 07:32:51 -07:00
Stefan Metzmacher e307e66981 io_uring/net: introduce IORING_SEND_ZC_REPORT_USAGE flag
It might be useful for applications to detect if a zero copy transfer with
SEND[MSG]_ZC was actually possible or not. The application can fallback to
plain SEND[MSG] in order to avoid the overhead of two cqes per request. Or
it can generate a log message that could indicate to an administrator that
no zero copy was possible and could explain degraded performance.

Cc: stable@vger.kernel.org # 6.1
Link: https://lore.kernel.org/io-uring/fb6a7599-8a9b-15e5-9b64-6cd9d01c6ff4@gmail.com/T/#m2b0d9df94ce43b0e69e6c089bdff0ce6babbdfaa
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8945b01756d902f5d5b0667f20b957ad3f742e5e.1666895626.git.metze@samba.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-21 07:38:31 -07:00
Jens Axboe 6dcabcd398 io_uring: fix typo in io_uring.h comment
Just a basic s/thig/this swap, fixing up a typo introduced by a commit
added in the 6.1 release.

Fixes: 9cda70f622 ("io_uring: introduce fixed buffer support for io_uring_cmd")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-06 13:17:27 -07:00
Anuj Gupta 9cda70f622 io_uring: introduce fixed buffer support for io_uring_cmd
Add IORING_URING_CMD_FIXED flag that is to be used for sending io_uring
command with previously registered buffers. User-space passes the buffer
index in sqe->buf_index, same as done in read/write variants that uses
fixed buffers.

Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20220930062749.152261-3-anuj20.g@samsung.com
[axboe: shuffle valid flags check before acting on it]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-30 07:50:59 -06:00
Pavel Begunkov 493108d95f io_uring/net: zerocopy sendmsg
Add a zerocopy version of sendmsg.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6aabc4bdfc0ec78df6ec9328137e394af9d4e7ef.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 13:15:02 -06:00
Dylan Yudaken c0e0d6ba25 io_uring: add IORING_SETUP_DEFER_TASKRUN
Allow deferring async tasks until the user calls io_uring_enter(2) with
the IORING_ENTER_GETEVENTS flag. Enable this mode with a flag at
io_uring_setup time. This functionality requires that the later
io_uring_enter will be called from the same submission task, and therefore
restrict this flag to work only when IORING_SETUP_SINGLE_ISSUER is also
set.

Being able to hand pick when tasks are run prevents the problem where
there is current work to be done, however task work runs anyway.

For example, a common workload would obtain a batch of CQEs, and process
each one. Interrupting this to additional taskwork would add latency but
not gain anything. If instead task work is deferred to just before more
CQEs are obtained then no additional latency is added.

The way this is implemented is by trying to keep task work local to a
io_ring_ctx, rather than to the submission task. This is required, as the
application will want to wake up only a single io_ring_ctx at a time to
process work, and so the lists of work have to be kept separate.

This has some other benefits like not having to check the task continually
in handle_tw_list (and potentially unlocking/locking those), and reducing
locks in the submit & process completions path.

There are networking cases where using this option can reduce request
latency by 50%. For example a contrived example using [1] where the client
sends 2k data and receives the same data back while doing some system
calls (to trigger task work) shows this reduction. The reason ends up
being that if sending responses is delayed by processing task work, then
the client side sits idle. Whereas reordering the sends first means that
the client runs it's workload in parallel with the local task work.

[1]:
Using https://github.com/DylanZA/netbench/tree/defer_run
Client:
./netbench  --client_only 1 --control_port 10000 --host <host> --tx "epoll --threads 16 --per_thread 1 --size 2048 --resp 2048 --workload 1000"
Server:
./netbench  --server_only 1 --control_port 10000  --rx "io_uring --defer_taskrun 0 --workload 100"   --rx "io_uring  --defer_taskrun 1 --workload 100"

Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220830125013.570060-5-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 10:30:42 -06:00
Pavel Begunkov b48c312be0 io_uring/net: simplify zerocopy send user API
Following user feedback, this patch simplifies zerocopy send API. One of
the main complaints is that the current API is difficult with the
userspace managing notification slots, and then send retries with error
handling make it even worse.

Instead of keeping notification slots change it to the per-request
notifications model, which posts both completion and notification CQEs
for each request when any data has been sent, and only one CQE if it
fails. All notification CQEs will have IORING_CQE_F_NOTIF set and
IORING_CQE_F_MORE in completion CQEs indicates whether to wait a
notification or not.

IOSQE_CQE_SKIP_SUCCESS is disallowed with zerocopy sends for now.

This is less flexible, but greatly simplifies the user API and also the
kernel implementation. We reuse notif helpers in this patch, but in the
future there won't be need for keeping two requests.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/95287640ab98fc9417370afb16e310677c63e6ce.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-01 09:13:33 -06:00
Pavel Begunkov 57f332246a io_uring/notif: remove notif registration
We're going to remove the userspace exposed zerocopy notification API,
remove notification registration.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6ff00b97be99869c386958a990593c9c31cf105b.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-01 09:13:33 -06:00
Pavel Begunkov d9808ceb31 Revert "io_uring: rename IORING_OP_FILES_UPDATE"
This reverts commit 4379d5f15b.

We removed notification flushing, also cleanup uapi preparation changes
to not pollute it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/89edc3905350f91e1b6e26d9dbf42ee44fd451a2.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-01 09:13:33 -06:00
Pavel Begunkov 23c12d5fc0 Revert "io_uring: add zc notification flush requests"
This reverts commit 492dddb4f6.

Soon we won't have the very notion of notification flushing, so remove
notification flushing requests.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8850334ca56e65b413cb34fd158db81d7b2865a3.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-01 09:13:33 -06:00
Ammar Faizi e1d0c6d05a io_uring: uapi: Add `extern "C"` in io_uring.h for liburing
Make it easy for liburing to integrate uapi header with the kernel.
Previously, when this header changes, the liburing side can't directly
copy this header file due to some small differences. Sync them.

Link: https://lore.kernel.org/io-uring/f1feef16-6ea2-0653-238f-4aaee35060b6@kernel.dk
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Dylan Yudaken <dylany@fb.com>
Cc: Facebook Kernel Team <kernel-team@fb.com>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-23 07:22:33 -06:00
Pavel Begunkov 492dddb4f6 io_uring: add zc notification flush requests
Overlay notification control onto IORING_OP_RSRC_UPDATE (former
IORING_OP_FILES_UPDATE). It allows to flush a range of zc notifications
from slots with indexes [sqe->off, sqe->off+sqe->len). If sqe->arg is
not zero, it also copies sqe->arg as a new tag for all flushed
notifications.

Note, it doesn't flush a notification of a slot if there was no requests
attached to it (since last flush or registration).

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/df13e2363400682a73dd9e71c3b990b8d1ff0333.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Pavel Begunkov 4379d5f15b io_uring: rename IORING_OP_FILES_UPDATE
IORING_OP_FILES_UPDATE will be a more generic opcode serving different
resource types, rename it into IORING_OP_RSRC_UPDATE and add subtype
handling.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0a907133907d9af3415a8a7aa1802c6aa97c03c6.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Pavel Begunkov 63809137eb io_uring: flush notifiers after sendzc
Allow to flush notifiers as a part of sendzc request by setting
IORING_SENDZC_FLUSH flag. When the sendzc request succeedes it will
flush the used [active] notifier.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e0b4d9a6797e2fd6092824fe42953db7a519bbc8.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Pavel Begunkov 10c7d33ecd io_uring: sendzc with fixed buffers
Allow zerocopy sends to use fixed buffers. There is an optimisation for
this case, the network layer don't need to reference the pages, see
SKBFL_MANAGED_FRAG_REFS, so io_uring have to ensure validity of fixed
buffers until the notifier is released.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e1d8bd1b5934e541d90c1824eb4020ae3f5f43f3.1657643355.git.asml.silence@gmail.com
[axboe: fold in 32-bit pointer cast warning fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Pavel Begunkov 092aeedb75 io_uring: allow to pass addr into sendzc
Allow to specify an address to zerocopy sends making it more like
sendto(2).

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/70417a8f7c5b51ab454690bae08adc0c187f89e8.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Pavel Begunkov 06a5464be8 io_uring: wire send zc request type
Add a new io_uring opcode IORING_OP_SENDZC. The main distinction from
IORING_OP_SEND is that the user should specify a notification slot
index in sqe::notification_idx and the buffers are safe to reuse only
when the used notification is flushed and completes.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a80387c6a68ce9cf99b3b6ef6f71068468761fb7.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Pavel Begunkov bc24d6bd32 io_uring: add notification slot registration
Let the userspace to register and unregister notification slots.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a0aa8161fe3ebb2a4cc6e5dbd0cffb96e6881cf5.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Dylan Yudaken 9bb66906f2 io_uring: support multishot in recvmsg
Similar to multishot recv, this will require provided buffers to be
used. However recvmsg is much more complex than recv as it has multiple
outputs. Specifically flags, name, and control messages.

Support this by introducing a new struct io_uring_recvmsg_out with 4
fields. namelen, controllen and flags match the similar out fields in
msghdr from standard recvmsg(2), payloadlen is the length of the payload
following the header.
This struct is placed at the start of the returned buffer. Based on what
the user specifies in struct msghdr, the next bytes of the buffer will be
name (the next msg_namelen bytes), and then control (the next
msg_controllen bytes). The payload will come at the end. The return value
in the CQE is the total used size of the provided buffer.

Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220714110258.1336200-4-dylany@fb.com
[axboe: style fixups, see link]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:18 -06:00
Dylan Yudaken b3fdea6ecb io_uring: multishot recv
Support multishot receive for io_uring.
Typical server applications will run a loop where for each recv CQE it
requeues another recv/recvmsg.

This can be simplified by using the existing multishot functionality
combined with io_uring's provided buffers.
The API is to add the IORING_RECV_MULTISHOT flag to the SQE. CQEs will
then be posted (with IORING_CQE_F_MORE flag set) when data is available
and is read. Once an error occurs or the socket ends, the multishot will
be removed and a completion without IORING_CQE_F_MORE will be posted.

The benefit to this is that the recv is much more performant.
 * Subsequent receives are queued up straight away without requiring the
   application to finish a processing loop.
 * If there are more data in the socket (sat the provided buffer size is
   smaller than the socket buffer) then the data is immediately
   returned, improving batching.
 * Poll is only armed once and reused, saving CPU cycles

Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220630091231.1456789-11-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:17 -06:00
Pavel Begunkov 6e73dffbb9 io_uring: let to set a range for file slot allocation
From recently io_uring provides an option to allocate a file index for
operation registering fixed files. However, it's utterly unusable with
mixed approaches when for a part of files the userspace knows better
where to place it, as it may race and users don't have any sane way to
pick a slot and hoping it will not be taken.

Let the userspace to register a range of fixed file slots in which the
auto-allocation happens. The use case is splittting the fixed table in
two parts, where on of them is used for auto-allocation and another for
slot-specified operations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/66ab0394e436f38437cf7c44676e1920d09687ad.1656154403.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:16 -06:00
Jens Axboe e6130eba8a io_uring: add support for passing fixed file descriptors
With IORING_OP_MSG_RING, one ring can send a message to another ring.
Extend that support to also allow sending a fixed file descriptor to
that ring, enabling one ring to pass a registered descriptor to another
one.

Arguments are extended to pass in:

sqe->addr3	fixed file slot in source ring
sqe->file_index	fixed file slot in destination ring

IORING_OP_MSG_RING is extended to take a command argument in sqe->addr.
If set to zero (or IORING_MSG_DATA), it sends just a message like before.
If set to IORING_MSG_SEND_FD, a fixed file descriptor is sent according
to the above arguments.

Two common use cases for this are:

1) Server needs to be shutdown or restarted, pass file descriptors to
   another onei

2) Backend is split, and one accepts connections, while others then get
  the fd passed and handle the actual connection.

Both of those are classic SCM_RIGHTS use cases, and it's not possible to
support them with direct descriptors today.

By default, this will post a CQE to the target ring, similarly to how
IORING_MSG_DATA does it. If IORING_MSG_RING_CQE_SKIP is set, no message
is posted to the target ring. The issuer is expected to notify the
receiver side separately.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:16 -06:00
Gustavo A. R. Silva 8fcf4c48f4 io_uring: replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:16 -06:00
Jens Axboe 78a861b949 io_uring: add sync cancelation API through io_uring_register()
The io_uring cancelation API is async, like any other API that we expose
there. For the case of finding a request to cancel, or not finding one,
it is fully sync in that when submission returns, the CQE for both the
cancelation request and the targeted request have been posted to the
CQ ring.

However, if the targeted work is being executed by io-wq, the API can
only start the act of canceling it. This makes it difficult to use in
some circumstances, as the caller then has to wait for the CQEs to come
in and match on the same cancelation data there.

Provide a IORING_REGISTER_SYNC_CANCEL command for io_uring_register()
that does sync cancelations, always. For the io-wq case, it'll wait
for the cancelation to come in before returning. The only expected
returns from this API is:

0		Request found and canceled fine.
> 0		Requests found and canceled. Only happens if asked to
		cancel multiple requests, and if the work wasn't in
		progress.
-ENOENT		Request not found.
-ETIME		A timeout on the operation was requested, but the timeout
		expired before we could cancel.

and we won't get -EALREADY via this API.

If the timeout value passed in is -1 (tv_sec and tv_nsec), then that
means that no timeout is requested. Otherwise, the timespec passed in
is the amount of time the sync cancel will wait for a successful
cancelation.

Link: https://github.com/axboe/liburing/discussions/608
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:15 -06:00
Jens Axboe 7d8ca72501 io_uring: add IORING_ASYNC_CANCEL_FD_FIXED cancel flag
In preparation for not having a request to pass in that carries this
state, add a separate cancelation flag that allows the caller to ask
for a fixed file for cancelation.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:15 -06:00
Pavel Begunkov 97bbdc06a4 io_uring: add IORING_SETUP_SINGLE_ISSUER
Add a new IORING_SETUP_SINGLE_ISSUER flag and the userspace visible part
of it, i.e. put limitations of submitters. Also, don't allow it together
with IOPOLL as we're not going to put it to good use.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4bcc41ee467fdf04c8aab8baf6ce3ba21858c3d4.1655371007.git.asml.silence@gmail.com
Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:13 -06:00
Jens Axboe b9ba8a4463 io_uring: add support for level triggered poll
By default, the POLL_ADD command does edge triggered poll - if we get
a non-zero mask on the initial poll attempt, we complete the request
successfully.

Support level triggered by always waiting for a notification, regardless
of whether or not the initial mask matches the file state.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Pavel Begunkov bdb2c48e4b io_uring: explicit sqe padding for ioctl commands
32 bit sqe->cmd_op is an union with 64 bit values. It's always a good
idea to do padding explicitly. Also zero check it in prep, so it can be
used in the future if needed without compatibility concerns.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e6b95a05e970af79000435166185e85b196b2ba2.1657202417.git.asml.silence@gmail.com
[axboe: turn bitwise OR into logical variant]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-07 17:33:01 -06:00
Pavel Begunkov 29c1ac230e io_uring: keep sendrecv flags in ioprio
We waste a u64 SQE field for flags even though we don't need as many
bits and it can be used for something more useful later. Store io_uring
specific send/recv flags in sqe->ioprio instead of ->addr2.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Fixes: 0455d4ccec ("io_uring: add POLL_FIRST support for send/sendmsg and recv/recvmsg")
[axboe: change comment in io_uring.h as well]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-30 07:15:50 -06:00
Pavel Begunkov d884b6498d io_uring: remove IORING_CLOSE_FD_AND_FILE_SLOT
This partially reverts a7c41b4687

Even though IORING_CLOSE_FD_AND_FILE_SLOT might save cycles for some
users, but it tries to do two things at a time and it's not clear how to
handle errors and what to return in a single result field when one part
fails and another completes well. Kill it for now.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/837c745019b3795941eee4fcfd7de697886d645b.1655224415.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-14 10:57:40 -06:00
Xiaoguang Wang a7c41b4687 io_uring: let IORING_OP_FILES_UPDATE support choosing fixed file slots
One big issue with the file registration feature is that it needs user
space apps to maintain free slot info about io_uring's fixed file table,
which really is a burden for development. io_uring now supports choosing
free file slot for user space apps by using IORING_FILE_INDEX_ALLOC flag
in accept, open, and socket operations, but they need the app to use
direct accept or direct open, which not all apps are prepared to use yet.

To support apps that still need real fds, make use of the registration
feature easier. Let IORING_OP_FILES_UPDATE support choosing fixed file
slots, which will store picked fixed files slots in fd array and let cqe
return the number of slots allocated.

Suggested-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
[axboe: move flag to uapi io_uring header, change goto to break, init]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-31 02:50:06 -06:00
Linus Torvalds 9836e93c0a for-5.19/io_uring-passthrough-2022-05-22
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmKKovAQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpv9oD/4qCs7k3bPZZWZ6xoWb4EObyyWOUifi26lp
 vpsJHFUbA67S/i4++LV9H18SazWJ7h08ac4bjgZ+NQz40/1WkTN8/Fa76jo+BnNK
 7T10Wp4Ak6uwWVrKaA81pnT+G9+xmHlJ3X27aKxzLuT7BEPpShZ6ouFVjTkx9CzN
 LrLjuCDTOBBN+ZoaroWYfdLwTQX2VCAl9B15lOtQIlFvuuU8VlrvLboY+80K8TvY
 1wvTA2HTjnXoYx+/cTTMIFZIwQH3r1hsbwEDD8/YJj1+ouhSRQ1b0p/nk2pA+3ws
 HF5r/YS/rLBjlPF094IzeOBaUyA433AN1VhZqnII8ek7ViT3W3x+BRrgE9O6ZkWT
 0AjX1BXReI5rdFmxBmwsSdBnrSoGaJOf2GdsCCdubXBIi+F/RvyajrPf7PTB5zbW
 9WEK/uy3xvZsRVkUGAzOb9QGdvjcllgMzwPJsDegDCw5PdcPdT3mzy6KGIWipFLp
 j8R+br7hRMpOJv/YpihJDMzSDkQ/r1/SCwR4fpLid/QdSHG/eRTQK6c4Su5bNYEy
 QDy2F6kQdBVtEJCQHcEOsbhXzSTNBcdB+ujUUM5653FkaHe6y4JbomLrsNx407Id
 i/4ROwA5K1dioJx503Eap+OhbI5rV+PFytJTwxvLrNyVGccwbH2YOVq80fsVBP2e
 cZbn6EX4Vg==
 =/peE
 -----END PGP SIGNATURE-----

Merge tag 'for-5.19/io_uring-passthrough-2022-05-22' of git://git.kernel.dk/linux-block

Pull io_uring NVMe command passthrough from Jens Axboe:
 "On top of everything else, this adds support for passthrough for
  io_uring.

  The initial feature for this is NVMe passthrough support, which allows
  non-filesystem based IO commands and admin commands.

  To support this, io_uring grows support for SQE and CQE members that
  are twice as big, allowing to pass in a full NVMe command without
  having to copy data around. And to complete with more than just a
  single 32-bit value as the output"

* tag 'for-5.19/io_uring-passthrough-2022-05-22' of git://git.kernel.dk/linux-block: (22 commits)
  io_uring: cleanup handling of the two task_work lists
  nvme: enable uring-passthrough for admin commands
  nvme: helper for uring-passthrough checks
  blk-mq: fix passthrough plugging
  nvme: add vectored-io support for uring-cmd
  nvme: wire-up uring-cmd support for io-passthru on char-device.
  nvme: refactor nvme_submit_user_cmd()
  block: wire-up support for passthrough plugging
  fs,io_uring: add infrastructure for uring-cmd
  io_uring: support CQE32 for nop operation
  io_uring: enable CQE32
  io_uring: support CQE32 in /proc info
  io_uring: add tracing for additional CQE32 fields
  io_uring: overflow processing for CQE32
  io_uring: flush completions for CQE32
  io_uring: modify io_get_cqe for CQE32
  io_uring: add CQE32 completion processing
  io_uring: add CQE32 setup processing
  io_uring: change ring size calculation for CQE32
  io_uring: store add. return values for CQE32
  ...
2022-05-23 13:06:15 -07:00
Linus Torvalds e1a8fde720 for-5.19/io_uring-net-2022-05-22
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmKKotMQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpmVwEACo7qBTjrrneZEwlYUWrSr45QtDNsQHPWjv
 aoK1dBLVH4ZjoZoOTI/aYcRgd5IJYo1P6I9tUrolM/+N3adM4UTEVC7i2PYDOaL3
 WUm/YT2aSLiyHaHQON7SMyGSVU8kfM9YvJAGbj7ohalO9A2VVtHfUAmcAtBdgWqv
 Dl/Uu6vbogOl19xztAwN4nvwqljA+GUMnbHJ/oeASzrMzYMOdQ0q3UsQbEt+pTXt
 rBzv8fCsrKsT2uBc59Bi3eFKeBMM6ERzux/40TlqcOnXf3KUCK7nM4VaRgPbvXdt
 GOOYfYs+j9L8SSEedvdKyYNq4vVwWgYfTRAKMNB0FPiOaTGZuUthqkgRZGYY8AA9
 +lJWxa+mzPmWEOmL+E44kt0OwtKDHX72ccEJUD7PHhTp0g87yKZfS6mXRNYLSxm7
 IYt7N1x3cOp0lrwUTvLDnSPOTuYOSEiB2JZtfkf+y3SuI5SWowIcudKOuO5p7G1r
 IpAROsZrpHzMf/eniINoX3IrqBSqr254jzwq+9IgUaw/ky76oPYqM1dWP9BnVxCg
 PXgvfT5zj6xrU43TxTeIPU92JoAqhMeXi6dcyoiAAf9+8Vih+sbmLzAdJbYb5F2v
 G0ISy31+x/Goi43fQS59HzS/MNXJplcmy2mxKUYBT7/ZoJ2A26Q8SukTWD+U8sDn
 XIrV4HEOUQ==
 =PUw1
 -----END PGP SIGNATURE-----

Merge tag 'for-5.19/io_uring-net-2022-05-22' of git://git.kernel.dk/linux-block

Pull io_uring 'more data in socket' support from Jens Axboe:
 "To be able to fully utilize the 'poll first' support in the core
  io_uring branch, it's advantageous knowing if the socket was empty
  after a receive. This adds support for that"

* tag 'for-5.19/io_uring-net-2022-05-22' of git://git.kernel.dk/linux-block:
  io_uring: return hint on whether more data is available after receive
  tcp: pass back data left in socket after receive
2022-05-23 12:51:04 -07:00
Linus Torvalds 368da430d0 for-5.19/io_uring-socket-2022-05-22
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmKKorgQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpm0eEACdTzhm7h5cXn9KjIvWLkdocAb/NOL8GYPn
 Q1mY1SqKQFZvs/fyKHkkZEiIBPxhvN6snVFXMpb4LDmPYeeH4GTUlNomrGTIjvf/
 j6SnZN4lCs9A2NlE+iDVWnFQOPQFALza2Y9BhC5xzay326qnKlO+0fQv3C1vXXrc
 /PNLqxQr7+GmO0a0PJnS6mGWGj6qF7nLqilB9apnKsTK6BKbJEec6ciKreqxU6ME
 WHaux11uIAbcf8rc6C/2myEK0k6jCOAue3vZ0lizygf+8klUCl2vMqV5BLwCBlXG
 /e7hBsUUrGr0CG0fryqhQQTUxsZLshioBbQH1vttSeZCli46mmWWAhPNy3/jb1ZU
 72bazA84Fe9ney9uVZvZoMoBsG+6t6UOatqND13MeRFAXnkRr0jZRuau2iBxgqAr
 OINJW+IVPU7IrCD+S4lV1/LCdhLhYcob8/zfKmIrdHMQnWG/gLonVpYJIBCyLDAv
 2jvHFIPJuSMUSGVjRKCb16LLNV6u7YG6VOWbKuippxfJxDdwA3TOtOhvTJIpYq0u
 TotPgpZ7bfcr4xDsGgD9mZS8E7jwsL/G0/MwsnixELykEXuhd++sgoTbr+RyUYdV
 45Hm6DsxlytjzOb/5uQrqhwrso05eVt14K74XApPa3fWKL8aWCh1jGSdo3CSbIyW
 iHwss919Ag==
 =nb5i
 -----END PGP SIGNATURE-----

Merge tag 'for-5.19/io_uring-socket-2022-05-22' of git://git.kernel.dk/linux-block

Pull io_uring socket() support from Jens Axboe:
 "This adds support for socket(2) for io_uring. This is handy when using
  direct / registered file descriptors with io_uring.

  Outside of those two patches, a small series from Dylan on top that
  improves the tracing by providing a text representation of the opcode
  rather than needing to decode this by reading the header file every
  time.

  That sits in this branch as it was the last opcode added (until it
  wasn't...)"

* tag 'for-5.19/io_uring-socket-2022-05-22' of git://git.kernel.dk/linux-block:
  io_uring: use the text representation of ops in trace
  io_uring: rename op -> opcode
  io_uring: add io_uring_get_opcode
  io_uring: add type to op enum
  io_uring: add socket(2) support
  net: add __sys_socket_file()
2022-05-23 12:42:33 -07:00
Linus Torvalds 09beaff75e for-5.19/io_uring-xattr-2022-05-22
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmKKopkQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpgakEACktFtUBQLrYOXbM/mVxMpR//ht4e29E8k0
 j/DkqK0yDKn9VkvDryALguH+ixNSI9Z4N7xSELLb/meNQsbJ7YdprL3xJn3BoUgs
 3zx44janE8J3Q5TsXvD2z2jPIMaT892t5+5aLFYZqP1g+KDXI8T1WpHsETMkKfRG
 ZPeerUrd0fhtnDpViaaYbRutIEt8V8tsPhh0XG/4GojWjUW0FTsRKBSGuQ0sQnUr
 aJDfF5VylOjOBzRGimGZ23vJIgtZ8UEpX0T2MxR5V6ffj4cI8bCFQOrphh7yHxF5
 f09xte80zX6pow5AivIpultZShR6IoQG5DIvF59woNP16uXy5yUyVTQvdnt8RlyY
 RjLd8ro9Gt4wBQGqckJLyY/o1FGhaQ8S99wOixUlpb9qKAOGmQZI97FQKFENqx/1
 Xe+bP6QmTt9uCXsYPIFBtZaaEv2u0yjHOyERFUSzKJQUuPTa5Rmen0EXYXRhe5/E
 p+sR3Qbk1wzlW7UHuCT2gcaI67SAFG+yDv1U6BAaVdcS71i0WCA+Q2a6AuB+NJzg
 ER4+JRoeOnjEXSP2UPvIUBL1Komdj4R2hnrOK4S80R3yQ3NaadrWywhBn5HNcniM
 wE2P6J0erzRFqyfBw9tyNLsZwR1iS7JqSD9/NuBLoWwb42O0l+WgqqwDTSxMsde4
 egKBaidRqg==
 =CfhD
 -----END PGP SIGNATURE-----

Merge tag 'for-5.19/io_uring-xattr-2022-05-22' of git://git.kernel.dk/linux-block

Pull io_uring xattr support from Jens Axboe:
 "Support for the xattr variants"

* tag 'for-5.19/io_uring-xattr-2022-05-22' of git://git.kernel.dk/linux-block:
  io_uring: cleanup error-handling around io_req_complete
  io_uring: fix trace for reduced sqe padding
  io_uring: add fgetxattr and getxattr support
  io_uring: add fsetxattr and setxattr support
  fs: split off do_getxattr from getxattr
  fs: split off setxattr_copy and do_setxattr function from setxattr
2022-05-23 12:30:30 -07:00
Jens Axboe c7fb19428d io_uring: add support for ring mapped supplied buffers
Provided buffers allow an application to supply io_uring with buffers
that can then be grabbed for a read/receive request, when the data
source is ready to deliver data. The existing scheme relies on using
IORING_OP_PROVIDE_BUFFERS to do that, but it can be difficult to use
in real world applications. It's pretty efficient if the application
is able to supply back batches of provided buffers when they have been
consumed and the application is ready to recycle them, but if
fragmentation occurs in the buffer space, it can become difficult to
supply enough buffers at the time. This hurts efficiency.

Add a register op, IORING_REGISTER_PBUF_RING, which allows an application
to setup a shared queue for each buffer group of provided buffers. The
application can then supply buffers simply by adding them to this ring,
and the kernel can consume then just as easily. The ring shares the head
with the application, the tail remains private in the kernel.

Provided buffers setup with IORING_REGISTER_PBUF_RING cannot use
IORING_OP_{PROVIDE,REMOVE}_BUFFERS for adding or removing entries to the
ring, they must use the mapped ring. Mapped provided buffer rings can
co-exist with normal provided buffers, just not within the same group ID.

To gauge overhead of the existing scheme and evaluate the mapped ring
approach, a simple NOP benchmark was written. It uses a ring of 128
entries, and submits/completes 32 at the time. 'Replenish' is how
many buffers are provided back at the time after they have been
consumed:

Test			Replenish			NOPs/sec
================================================================
No provided buffers	NA				~30M
Provided buffers	32				~16M
Provided buffers	 1				~10M
Ring buffers		32				~27M
Ring buffers		 1				~27M

The ring mapped buffers perform almost as well as not using provided
buffers at all, and they don't care if you provided 1 or more back at
the same time. This means application can just replenish as they go,
rather than need to batch and compact, further reducing overhead in the
application. The NOP benchmark above doesn't need to do any compaction,
so that overhead isn't even reflected in the above test.

Co-developed-by: Dylan Yudaken <dylany@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-18 06:12:42 -06:00
Hao Xu 390ed29b5e io_uring: add IORING_ACCEPT_MULTISHOT for accept
add an accept_flag IORING_ACCEPT_MULTISHOT for accept, which is to
support multishot.

Signed-off-by: Hao Xu <howeyxu@tencent.com>
Link: https://lore.kernel.org/r/20220514142046.58072-2-haoxu.linux@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-14 08:34:22 -06:00
Jens Axboe a8da73a32b io_uring: add flag for allocating a fully sparse direct descriptor space
Currently to setup a fully sparse descriptor space upfront, the app needs
to alloate an array of the full size and memset it to -1 and then pass
that in. Make this a bit easier by allowing a flag that simply does
this internally rather than needing to copy each slot separately.

This works with IORING_REGISTER_FILES2 as the flag is set in struct
io_uring_rsrc_register, and is only allow when the type is
IORING_RSRC_FILE as this doesn't make sense for registered buffers.

Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-13 06:28:50 -06:00
Jens Axboe 1339f24b33 io_uring: allow allocated fixed files for openat/openat2
If the application passes in IORING_FILE_INDEX_ALLOC as the file_slot,
then that's a hint to allocate a fixed file descriptor rather than have
one be passed in directly.

This can be useful for having io_uring manage the direct descriptor space.

Normal open direct requests will complete with 0 for success, and < 0
in case of error. If io_uring is asked to allocated the direct descriptor,
then the direct descriptor is returned in case of success.

Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-13 06:28:42 -06:00