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>
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
...
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
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()
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
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>
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>
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>
file_operations->uring_cmd is a file private handler.
This is somewhat similar to ioctl but hopefully a lot more sane and
useful as it can be used to enable many io_uring capabilities for the
underlying operation.
IORING_OP_URING_CMD is a file private kind of request. io_uring doesn't
know what is in this command type, it's for the provider of ->uring_cmd()
to deal with.
Co-developed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220511054750.20432-2-joshi.k@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Normal SQEs are 64-bytes in length, which is fine for all the commands
we support. However, in preparation for supporting passthrough IO,
provide an option for setting up a ring with 128-byte SQEs.
We continue to use the same type for io_uring_sqe, it's marked and
commented with a zero sized array pad at the end. This provides up
to 80 bytes of data for a passthrough command - 64 bytes for the
extra added data, and 16 bytes available at the end of the existing
SQE.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
* for-5.19/io_uring-socket:
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()
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
If IORING_RECVSEND_POLL_FIRST is set for recv/recvmsg or send/sendmsg,
then we arm poll first rather than attempt a receive or send upfront.
This can be useful if we expect there to be no data (or space) available
for the request, as we can then avoid wasting time on the initial
issue attempt.
Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If IORING_SETUP_COOP_TASKRUN is set to use cooperative scheduling for
running task_work, then IORING_SETUP_TASKRUN_FLAG can be set so the
application can tell if task_work is pending in the kernel for this
ring. This allows use cases like io_uring_peek_cqe() to still function
appropriately, or for the task to know when it would be useful to
call io_uring_wait_cqe() to run pending events.
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20220426014904.60384-7-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If this is set, io_uring will never use an IPI to deliver a task_work
notification. This can be used in the common case where a single task or
thread communicates with the ring, and doesn't rely on
io_uring_cqe_peek().
This provides a noticeable win in performance, both from eliminating
the IPI itself, but also from avoiding interrupting the submitting
task unnecessarily.
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20220426014904.60384-6-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For now just use a CQE flag for this, with big CQE support we could
return the actual number of bytes left.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rather than match on a specific key, be it user_data or file, allow
canceling any request that we can lookup. Works like
IORING_ASYNC_CANCEL_ALL in that it cancels multiple requests, but it
doesn't key off user_data or the file.
Can't be set with IORING_ASYNC_CANCEL_FD, as that's a key selector.
Only one may be used at the time.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20220418164402.75259-6-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently sqe->addr must contain the user_data of the request being
canceled. Introduce the IORING_ASYNC_CANCEL_FD flag, which tells the
kernel that we're keying off the file fd instead for cancelation. This
allows canceling any request that a) uses a file, and b) was assigned the
file based on the value being passed in.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20220418164402.75259-5-axboe@kernel.dk
The current cancelation will lookup and cancel the first request it
finds based on the key passed in. Add a flag that allows to cancel any
request that matches they key. It completes with the number of requests
found and canceled, or res < 0 if an error occured.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20220418164402.75259-4-axboe@kernel.dk
