io_sqe_buffer_register() currently calls io_put_rsrc_node() if it fails
to fully set up the io_rsrc_node. io_put_rsrc_node() is more involved
than necessary, since we already know the reference count will reach 0
and no io_mapped_ubuf has been attached to the node yet.
So just call io_free_node() to release the node's memory. This also
avoids the need to temporarily set the node's buf pointer to NULL.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://lore.kernel.org/r/20250228235916.670437-3-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull io_uring fix from Jens Axboe:
"Just a single fix headed for stable, ensuring that msg_control is
properly saved in compat mode as well"
* tag 'io_uring-6.14-20250228' of git://git.kernel.dk/linux:
io_uring/net: save msg_control for compat
Provide an interface for the kernel to leverage the existing
pre-registered buffers that io_uring provides. User space can reference
these later to achieve zero-copy IO.
User space must register an empty fixed buffer table with io_uring in
order for the kernel to make use of it.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20250227223916.143006-5-kbusch@meta.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A code rework resulted in an uninitialized return code when COMPAT
mode is disabled:
io_uring/net.c:722:6: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
722 | if (io_is_compat(req->ctx)) {
| ^~~~~~~~~~~~~~~~~~~~~~
io_uring/net.c:736:15: note: uninitialized use occurs here
736 | if (unlikely(ret))
| ^~~
Since io_is_compat() turns into a compile-time 'false', the #ifdef
here is completely unnecessary, and removing it avoids the warning.
Fixes: 51e158d405 ("io_uring/net: unify *mshot_prep calls with compat")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250227132018.1111094-1-arnd@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Normally, net/ would verify msghdr before importing iovec, for example
see copy_msghdr_from_user(), which further assumed by __copy_msghdr()
validating msg->msg_iovlen.
io_uring does it in reverse order, which is fine, but it'll be more
convenient for flip it so that the iovec business is done at the end and
eventually can be nicely pulled out of msghdr parsing section and
thought as a sepaarate step. That also makes structure accesses more
localised, which should be better for caches.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/cd35dc1b48d4e6e31f59ae7304c037fbe8a3fd3d.1740569495.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The user access section in io_msg_copy_hdr() is overextended by covering
selected buffers. It's hard to work with and prone to errors. Limit the
section to msghdr import only, selected buffers will do a separate
copy_from_user() call, and then move it into its own function. This
should be fine, selected buffer single shots are not important, for
multishots the overhead should be non-existent, and it's not that
expensive overall.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d3eb1f81c8cfbea9f1aa57dab90c472d2aa6e371.1740569495.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge mainline fixes into 6.15 branch, as upcoming patches depend on
fixes that went into the 6.14 mainline branch.
* io_uring-6.14:
io_uring/net: save msg_control for compat
io_uring/rw: clean up mshot forced sync mode
io_uring/rw: move ki_complete init into prep
io_uring/rw: don't directly use ki_complete
io_uring/rw: forbid multishot async reads
io_uring/rsrc: remove unused constants
io_uring: fix spelling error in uapi io_uring.h
io_uring: prevent opcode speculation
io-wq: backoff when retrying worker creation
Registered buffer are currently imported in two steps, first we lookup
a rsrc node and then use it to set up the iterator. The first part is
usually done at the prep stage, and import happens whenever it's needed.
As we want to defer binding to a node so that it works with linked
requests, combine both steps into a single helper.
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250224213116.3509093-6-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently multishot recvzc requests have no read limit and will remain
active so as long as the socket remains open. But, there are sometimes a
need to do a fixed length read e.g. peeking at some data in the socket.
Add a length limit to recvzc requests `len`. A value of 0 means no limit
which is the previous behaviour. A positive value N specifies how many
bytes to read from the socket.
Data will still be posted in aux completions, as before. This could be
split across multiple frags. But the primary recvzc request will now
complete once N bytes have been read. The completion of the recvzc
request will have res and cflags both set to 0.
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20250224041319.2389785-2-dw@davidwei.uk
[axboe: fixup io_zcrx_recv() for !CONFIG_NET]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_poll_issue() forwards the call to io_issue_sqe() and thus inherits
some of the handling. That's not particularly failure resistant, as for
example returning an innocently looking IOU_OK from a multishot issue
will lead to severe bugs.
Reimplement io_poll_issue() without io_issue_sqe()'s request completion
logic. Remove extra checks as we know that req->file is already set,
linked timeout are armed, and iopoll is not supported. Also cover it
with warnings for now.
The patch should be useful by itself, but it's also preparing the
codebase for other future clean ups.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3096d7b1026d9a52426a598bdfc8d9d324555545.1740331076.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull io_uring fixes from Jens Axboe:
- Series fixing an issue with multishot read on pollable files that may
return -EIOCBQUEUED from ->read_iter(). Four small patches for that,
the first one deliberately done in such a way that it'd be easy to
backport
- Remove some dead constant definitions
- Use array_index_nospec() for opcode indexing
- Work-around for worker creation retries in the presence of signals
* tag 'io_uring-6.14-20250221' of git://git.kernel.dk/linux:
io_uring/rw: clean up mshot forced sync mode
io_uring/rw: move ki_complete init into prep
io_uring/rw: don't directly use ki_complete
io_uring/rw: forbid multishot async reads
io_uring/rsrc: remove unused constants
io_uring: fix spelling error in uapi io_uring.h
io_uring: prevent opcode speculation
io-wq: backoff when retrying worker creation
For existing epoll event loops that can't fully convert to io_uring,
the used approach is usually to add the io_uring fd to the epoll
instance and use epoll_wait() to wait on both "legacy" and io_uring
events. While this work, it isn't optimal as:
1) epoll_wait() is pretty limited in what it can do. It does not support
partial reaping of events, or waiting on a batch of events.
2) When an io_uring ring is added to an epoll instance, it activates the
io_uring "I'm being polled" logic which slows things down.
Rather than use this approach, with EPOLL_WAIT support added to io_uring,
event loops can use the normal io_uring wait logic for everything, as
long as an epoll wait request has been armed with io_uring.
Note that IORING_OP_EPOLL_WAIT does NOT take a timeout value, as this
is an async request. Waiting on io_uring events in general has various
timeout parameters, and those are the ones that should be used when
waiting on any kind of request. If events are immediately available for
reaping, then This opcode will return those immediately. If none are
available, then it will post an async completion when they become
available.
cqe->res will contain either an error code (< 0 value) for a malformed
request, invalid epoll instance, etc. It will return a positive result
indicating how many events were reaped.
IORING_OP_EPOLL_WAIT requests may be canceled using the normal io_uring
cancelation infrastructure.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
