Refill queue region is a part of zcrx and should stay in struct
io_zcrx_ifq. We can't have multiple queues without it, so move it there.
As a result there is no context global zcrx region anymore, and the
region is looked up together with its ifq. To protect a concurrent mmap
from seeing an inconsistent region we were protecting changes to
->zcrx_region with mmap_lock, but now it protect the publishing of the
ifq.
Reviewed-by: David Wei <dw@davidwei.uk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/24f1a728fc03d0166f16d099575457e10d9d90f2.1745141261.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
sqe->file_index and sqe->zcrx_ifq_idx are aliased, so even though
io_recvzc_prep() has all necessary handling and checking for
->zcrx_ifq_idx, it's already rejected a couple of lines above.
It's not a real problem, however, as we can only have one ifq at the
moment, which index is always zero, and it returns correct error
codes to the user.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b51acedd326d1a87bf53e33303e6fc87661a3e3f.1745141261.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We want to have a full folio to be left pinned but with only one
reference, for that we "unpin" all but the first page with
unpin_user_pages(), which can be confusing. There is a new helper to
achieve that called unpin_user_folio(), so use that.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Link: https://lore.kernel.org/r/e0b2be8f9ea68f6b351ec3bb046f04f437f68491.1745083025.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There are two helpers here, one assigns and increments the node ref
count, and the other is simply a wrapper around that for the buffer node
handling.
The buffer node assignment benefits from checking and setting
REQ_F_BUF_NODE together, otherwise stalls have been observed on setting
that flag later in the process. Hence re-do it so that it's set when
checked, and cleared in case of (unlikely) failure. With that, the
buffer node helper can go, and then drop the generic
io_req_assign_rsrc_node() helper as well as there's only a single user
of it left at that point.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This works just like pipe2(2), except it also supports fixed file
descriptors. Used in a similar fashion as for other fd instantiating
opcodes (like accept, socket, open, etc), where sqe->file_slot is set
appropriately if two direct descriptors are desired rather than a set
of normal file descriptors.
sqe->addr must be set to a pointer to an array of 2 integers, which
is where the fixed/normal file descriptors are copied to.
sqe->pipe_flags contains flags, same as what is allowed for pipe2(2).
Future expansion of per-op private flags can go in sqe->ioprio,
like we do for other opcodes that take both a "syscall" flag set and
an io_uring opcode specific flag set.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The current situation with buffer group id juggling is not ideal.
req->buf_index first stores the bgid, then it's overwritten by a buffer
id, and then it can get restored back no recycling / etc. It's not so
easy to control, and it's not handled consistently across request types
with receive requests saving and restoring the bgid it by hand.
It's a prep patch that adds a buffer group id argument to
io_buffer_select(). The caller will be responsible for stashing a copy
somewhere and passing it into the function.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a210d6427cc3f4f42271a6853274cd5a50e56820.1743437358.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
struct io_wq stores do_work and free_work function pointers which are
called on each work item. But these function pointers are always set to
io_wq_submit_work and io_wq_free_work, respectively. So remove these
function pointers and just call the functions directly.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://lore.kernel.org/r/20250329161527.3281314-1-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is a problem with page pools not dma-unmapping immediately when
the device is going down, and delaying it until the page pool is
destroyed, which is not allowed (see links). That just got fixed for
normal page pools, and we need to address memory providers as well.
Unmap pages in the memory provider uninstall callback, and protect it
with a new lock. There is also a gap between when a dma mapping is
created and the mp is installed, so if the device is killed in between,
io_uring would be holding on to dma mappings to a dead device with no
one to call ->uninstall. Move it to page pool init and rely on
->is_mapped to make sure it's only done once.
Link: https://lore.kernel.org/lkml/8067f204-1380-4d37-8ffd-007fc6f26738@kernel.org/T/
Link: https://lore.kernel.org/all/20250409-page-pool-track-dma-v9-0-6a9ef2e0cba8@redhat.com/
Fixes: 34a3e60821 ("io_uring/zcrx: implement zerocopy receive pp memory provider")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ef9b7db249b14f6e0b570a1bb77ff177389f881c.1744965853.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
kbuf imports have the front offset adjusted and segments removed, but
the tail segments are still included in the segment count that gets
passed in the iov_iter. As the segments aren't necessarily all the
same size, move importing to a separate helper and iterate the
mapped length to get an exact count.
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Sending exact nr_segs, avoids bio split check and processing in
block layer, which takes around 5%[1] of overall CPU utilization.
In our setup, we see overall improvement of IOPS from 7.15M to 7.65M [2]
and 5% less CPU utilization.
[1]
3.52% io_uring [kernel.kallsyms] [k] bio_split_rw_at
1.42% io_uring [kernel.kallsyms] [k] bio_split_rw
0.62% io_uring [kernel.kallsyms] [k] bio_submit_split
[2]
sudo taskset -c 0,1 ./t/io_uring -b512 -d128 -c32 -s32 -p1 -F1 -B1 -n2
-r4 /dev/nvme0n1 /dev/nvme1n1
Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
[Pavel: fixed for kbuf, rebased and reworked on top of cleanups]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7a1a49a8d053bd617c244291d63dbfbc07afde36.1744882081.git.asml.silence@gmail.com
[axboe: fold in fix factoring in buf reg offset]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_import_fixed is a mess. Even though we know the final len of the
iterator, we still assign offset + len and do some magic after to
correct for that.
Do offset calculation first and finalise it with iov_iter_bvec at the
end.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2d5107fed24f8b23245ef2ede9a5a7f7c426df61.1744882081.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Kernel registered buffers are special because segments are not uniform
in size, and we have a bunch of optimisations based on that uniformity
for normal buffers. Handle kbuf separately, it'll be cleaner this way.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4e9e5990b0ab5aee723c0be5cd9b5bcf810375f9.1744882081.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Don't optimise for requests with offset=0. Large registered buffers are
the preference and hence the user is likely to pass an offset, and the
adjustments are not expensive and will be made even cheaper in following
patches.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1c2beb20470ee3c886a363d4d8340d3790db19f3.1744882081.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
IORING_OP_RECV_ZC requests take a zcrx object id via sqe::zcrx_ifq_idx,
which binds it to the corresponding if / queue. However, we don't return
that id back to the user. It's fine as currently there can be only one
zcrx and the user assumes that its id should be 0, but as we'll need
multiple zcrx objects in the future let's explicitly pass it back on
registration.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8714667d370651962f7d1a169032e5f02682a73e.1744722517.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This isn't fixing a real issue, but there's also zero point in going
through group and buffer setup, when the buffers are going to be
rejected once attempted to get used.
Cc: stable@vger.kernel.org
Reported-by: syzbot+58928048fd1416f1457c@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Refill queue lock and other bits are only used from the allocation path
on the rx softirq side, but it shares the cache line with other fields
like ctx that are used also in the "syscall" path, which causes cache
bouncing when softirq runs on a different CPU.
Separate them into different cache lines. The first one now contains
constant fields used by both contextx, followed by a line responsible
for refill queue data.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6d1f598e27d623c07fc49d6baee13089a9b1216c.1743848241.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Buffer / file table registration is all or nothing, if it fails all
resources we might have partially registered are dropped and the table
is killed. If that happens, it doesn't make sense to post any rsrc tag
CQEs. That would be confusing to the application, which should not need
to handle that case.
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Fixes: 7029acd8a9 ("io_uring/rsrc: get rid of per-ring io_rsrc_node list")
Link: https://lore.kernel.org/r/c514446a8dcb0197cddd5d4ba8f6511da081cf1f.1743777957.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_uring always switches requests to atomic refcounting for iowq
execution before there is any parallilism by setting REQ_F_REFCOUNT,
and the flag is not cleared until the request completes. That should be
fine as long as the compiler doesn't make up a non existing value for
the flags, however KCSAN still complains when the request owner changes
oter flag bits:
BUG: KCSAN: data-race in io_req_task_cancel / io_wq_free_work
...
read to 0xffff888117207448 of 8 bytes by task 3871 on cpu 0:
req_ref_put_and_test io_uring/refs.h:22 [inline]
Skip REQ_F_REFCOUNT checks for iowq, we know it's set.
Reported-by: syzbot+903a2ad71fb3f1e47cf5@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d880bc27fb8c3209b54641be4ff6ac02b0e5789a.1743679736.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_uring has supported fixed kernel buffer via io_buffer_register_bvec()
and io_buffer_unregister_bvec().
The vectored fixed buffer has been ready, so it is natural to support
fixed kernel buffer, one use case is ublk.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250325135155.935398-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When readlen is set for a recvzc request, tcp_read_sock() will call
io_zcrx_recv_skb() one final time with len == desc->count == 0. This is
caused by the !desc->count check happening too late. The offset + 1 !=
skb->len happens earlier and causes the while loop to continue.
Fix this in io_zcrx_recv_skb() instead of tcp_read_sock(). Return early
if len is 0 i.e. the read is done.
Fixes: 6699ec9a23 ("io_uring/zcrx: add a read limit to recvzc requests")
Signed-off-by: David Wei <dw@davidwei.uk>
Link: https://lore.kernel.org/r/20250401195355.1613813-1-dw@davidwei.uk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With registered buffers we set up iterators in helpers like
io_import_fixed(), and there is no need for a import_ubuf() before that.
It was fine as we used real pointers for offset calculation, but that's
not the case anymore since introduction of ublk kernel buffers.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9b2de1a50844f848f62c8de609b494971033a6b9.1743437358.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_send_setup() already sets up the iterator for IORING_OP_SEND_ZC, we
don't need repeating that at issue time. Move it all together with mem
accounting at prep time, which is more consistent with how the non-zc
version does that.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/eb54f007c493ad9f4ca89aa8e715baf30d83fb88.1743202294.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_sendmsg_zc_setup() duplicates parts of io_sendmsg_setup(), and the
only difference between them is that the former support vectored
registered buffers with nothing zerocopy specific. Merge them together,
we want regular sendmsg to eventually support fixed buffers either way.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7e5ec40f9dc93355399dc6fa0cbc8b31f0b20ac5.1743202294.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
