to #26323588

commit 711be0312df4d350fb5bf1671c132cccae5aaf9a upstream.

Move setting ctx->drain_next to the only place it could be set, when it
got linked non-head requests. The same for checking it, it's interesting
only for a head of a link or a non-linked request.

No functional changes here. This removes some code from the common path
and also removes REQ_F_DRAIN_LINK flag, as it doesn't need it anymore.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 66f4af93da5761d2fa05c0dc673a47003cdb9cfe upstream.

The application currently has no way of knowing if a given opcode is
supported or not without having to try and issue one and see if we get
-EINVAL or not. And even this approach is fraught with peril, as maybe
we're getting -EINVAL due to some fields being missing, or maybe it's
just not that easy to issue that particular command without doing some
other leg work in terms of setup first.

This adds IORING_REGISTER_PROBE, which fills in a structure with info
on what it supported or not. This will work even with sparse opcode
fields, which may happen in the future or even today if someone
backports specific features to older kernels.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 10fef4bebf979bb705feed087611293d5864adfe upstream.

We can't assume that the whole batch has fixed files in it. If it's a
mix, or none at all, then we can end up doing a ref put that either
messes up accounting, or causes an oops if we have no fixed files at
all.

Also ensure we free requests properly between inflight accounted and
normal requests.

Fixes: 82c721577011 ("io_uring: extend batch freeing to cover more cases")
Reported-by: NDmitrii Dolgov <9erthalion6@gmail.com>
Reported-by: NPavel Begunkov <asml.silence@gmail.com>
Tested-by: NDmitrii Dolgov <9erthalion6@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 354420f705ccd0aa2d41249f3bb55b4afbed1873 upstream.

For some test apps at least, user_data is just zeroes. So it's not a
good way to tell what the command actually is. Add the opcode to the
issue trace point.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit cebdb98617ae3e842c81c73758a185248b37cfd6 upstream.

Add support for the new openat2(2) system call. It's trivial to do, as
we can have openat(2) just be wrapped around it.
Suggested-by: NStefan Metzmacher <metze@samba.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit f8748881b17dc56b3faa1d30c823f071c56593e5 upstream.

We only use it internally in the prep functions for both statx and
openat, so we don't need it to be persistent across the request.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit c12cedf24e786509de031a832e6b0e5f8b3ca37b upstream.

We'll need this for openat2(2) support, remove flags and mode from
the existing io_open struct.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit f2842ab5b72d7ee5f7f8385c2d4f32c133f5837b upstream.

If an application is using eventfd notifications with poll to know when
new SQEs can be issued, it's expecting the following read/writes to
complete inline. And with that, it knows that there are events available,
and don't want spurious wakeups on the eventfd for those requests.

This adds IORING_REGISTER_EVENTFD_ASYNC, which works just like
IORING_REGISTER_EVENTFD, except it only triggers notifications for events
that happen from async completions (IRQ, or io-wq worker completions).
Any completions inline from the submission itself will not trigger
notifications.
Suggested-by: NMark Papadakis <markuspapadakis@icloud.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 69b3e546139a21b3046b6bf0cb79d5e8c9a3fa75 upstream.

In preparation for adding another one, which would make us spill into
another long (and hence bump the size of the ctx), change them to
bit fields.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit c150368b496837cb207712e78f903ccfd7633b93 upstream.

If an application attempts to register a set with unbounded requests
pending, we can be stuck here forever if they don't complete. We can
make this wait interruptible, and just abort if we get signaled.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 18c9a6bbe0645a05172a900740b9d2d379d54320 upstream.

This function will be used in a later patch to switch the struct
request_queue q_usage_counter from killed back to live. In contrast
to percpu_ref_reinit(), this new function does not require that the
refcount is zero.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Acked-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 96fd84d83a778450ffae737d9efa546ac3983b1f upstream.

Null check kfree is redundant, so remove it.
This is detected by coccinelle.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit fddafacee287b3140212c92464077e971401f860 upstream.

This adds IORING_OP_SEND for send(2) support, and IORING_OP_RECV for
recv(2) support.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 2550878f8421f7912fdd56b38c630b797f95c749 upstream.

io_wq workers use io_issue_sqe() to forward sqes and never
io_queue_sqe(). Remove extra check for io_wq_current_is_worker()
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit caf582c652feccd42c50923f0467c4f2dcef279e upstream.

It should be pretty rare to not submitting anything when there is
something in the ring. No need to keep heuristics for this case.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit ee7d46d9db19ded7b7222af95add63606318a480 upstream.

A user may ask to submit more than there is in the ring, and then
io_uring will submit as much as it can. However, in the last iteration
it will allocate an io_kiocb and immediately free it. It could do
better and adjust @to_submit to what is in the ring.

And since the ring's head is already checked here, there is no need to
do it in the loop, spamming with smp_load_acquire()'s barriers
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 9ef4f124894b7b9241a3cf5f9b40db0812783d66 upstream.

Make io_submit_sqes() to clamp @to_submit itself. It removes duplicated
code and prepares for following changes.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 8110c1a6212e430a84edd2b83fe9043def8b743e upstream.

Some applications like to start small in terms of ring size, and then
ramp up as needed. This is a bit tricky to do currently, since we don't
advertise the max ring size.

This adds IORING_SETUP_CLAMP. If set, and the values for SQ or CQ ring
size exceed what we support, then clamp them at the max values instead
of returning -EINVAL. Since we return the chosen ring sizes after setup,
no further changes are needed on the application side. io_uring already
changes the ring sizes if the application doesn't ask for power-of-two
sizes, for example.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit c6ca97b30c47c7ad36107d3764bb4dc37026d171 upstream.

Currently we only batch free if fixed files are used, no links, no aux
data, etc. This extends the batch freeing to only exclude the linked
case and fallback case, and make io_free_req_many() handle the other
cases just fine.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 8237e045983d82ba78eaab5f60b9300927fc6796 upstream.

This cleans up the code a bit, and it allows us to build on top of the
multi-req freeing.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 2b85edfc0c90efc68dea3d665bb4111bf0694e05 upstream.

percpu_ref_tryget() has its own overhead. Instead getting a reference
for each request, grab a bunch once per io_submit_sqes().

~5% throughput boost for a "submit and wait 128 nops" benchmark.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>

__io_req_free_empty() -> __io_req_do_free()
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 4e5ef02317b12e2ed3d604281ffb6b75261f7612 upstream.

Add percpu_ref_tryget_many(), which works the same way as
percpu_ref_tryget(), but grabs specified number of refs.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Acked-by: NDennis Zhou <dennis@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit c1ca757bd6f4632c510714631ddcc2d13030fe1e upstream.

This adds support for doing madvise(2) through io_uring. We assume that
any operation can block, and hence punt everything async. This could be
improved, but hard to make bullet proof. The async punt ensures it's
safe.
Reviewed-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit db08ca25253d56f1f76eb4b3fe32a7ac1fbab741 upstream.

This is in preparation for enabling this functionality through io_uring.
Add a helper that is just exporting what sys_madvise() does, and have the
system call use it.

No functional changes in this patch.
Reviewed-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 4840e418c2fc533d55ff6caa5b9313eed1d26cfd upstream.

This adds support for doing fadvise through io_uring. We assume that
WILLNEED doesn't block, but that DONTNEED may block.
Reviewed-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit ba04291eb66ed895f194ae5abd3748d72bf8aaea upstream.

This behaves like preadv2/pwritev2 with offset == -1, it'll use (and
update) the current file position. This obviously comes with the caveat
that if the application has multiple read/writes in flight, then the
end result will not be as expected. This is similar to threads sharing
a file descriptor and doing IO using the current file position.

Since this feature isn't easily detectable by doing a read or write,
add a feature flags, IORING_FEAT_RW_CUR_POS, to allow applications to
detect presence of this feature.
Reported-by: N李通洲 <carter.li@eoitek.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 3a6820f2bb8a079975109c25a5d1f29f46bce5d2 upstream.

For uses cases that don't already naturally have an iovec, it's easier
(or more convenient) to just use a buffer address + length. This is
particular true if the use case is from languages that want to create
a memory safe abstraction on top of io_uring, and where introducing
the need for the iovec may impose an ownership issue. For those cases,
they currently need an indirection buffer, which means allocating data
just for this purpose.

Add basic read/write that don't require the iovec.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit e94f141bd248ebdadcb7351f1e70b31cee5add53 upstream.

For busy IORING_OP_POLL_ADD workloads, we can have enough contention
on the completion lock that we fail the inline completion path quite
often as we fail the trylock on that lock. Add a list for deferred
completions that we can use in that case. This helps reduce the number
of async offloads we have to do, as if we get multiple completions in
a row, we'll piggy back on to the poll_llist instead of having to queue
our own offload.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit ad3eb2c89fb24d14ac81f43eff8e85fece2c934d upstream.

We currently check ->cq_overflow_list from both SQ and CQ context, which
causes some bouncing of that cache line. Add separate bits of state for
this instead, so that the SQ side can check using its own state, and
likewise for the CQ side.

This adds ->sq_check_overflow with the SQ state, and ->cq_check_overflow
with the CQ state. If we hit an overflow condition, both of these bits
are set. Likewise for overflow flush clear, we clear both bits. For the
fast path of just checking if there's an overflow condition on either
the SQ or CQ side, we can use our own private bit for this.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit d3656344fea0339fb0365c8df4d2beba4e0089cd upstream.

We currently have various switch statements that check if an opcode needs
a file, mm, etc. These are hard to keep in sync as opcodes are added. Add
a struct io_op_def that holds all of this information, so we have just
one spot to update when opcodes are added.

This also enables us to NOT allocate req->io if a deferred command
doesn't need it, and corrects some mistakes we had in terms of what
commands need mm context.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit add7b6b85a4dfa89283834d181e87ea2144b9028 upstream.

__io_free_req() and io_double_put_req() aren't used before they are
defined, so we can kill these two forwards.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 32fe525b6d10fec956cfe68f0db76839cd7f0ea5 upstream.

Move io_queue_link_head() to links handling code in io_submit_sqe(),
so it wouldn't need extra checks and would have better data locality.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 9d76377f7e13c19441fdd066033345289f89b5fe upstream.

Calling "prev" a head of a link is a bit misleading. Rename it
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit ce35a47a3a0208a77b4d31b7f2e8ed57d624093d upstream.

io_uring defaults to always doing inline submissions, if at all
possible. But for larger copies, even if the data is fully cached, that
can take a long time. Add an IOSQE_ASYNC flag that the application can
set on the SQE - if set, it'll ensure that we always go async for those
kinds of requests. Use the io-wq IO_WQ_WORK_CONCURRENT flag to ensure we
get the concurrency we desire for this case.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commmit 895e2ca0f693c672902191747b548bdc56f0c7de upstream.

io-wq assumes that work will complete fast (and not block), so it
doesn't create a new worker when work is enqueued, if we already have
at least one worker running. This is done on the assumption that if work
is running, then it will complete fast.

Add an option to force io-wq to fork a new worker for work queued. This
is signaled by setting IO_WQ_WORK_CONCURRENT on the work item. For that
case, io-wq will create a new worker, even though workers are already
running.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit eddc7ef52a6b37b7ba3d1c8a8fbb63d5d9914f8a upstream.

This provides support for async statx(2) through io_uring.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 3934e36f6099e6277db33f433fe135c6644e8ac2 upstream.

To implement an async stat, we need to provide the flags mapping and
the statx user copy. Make them available internally, through
fs/internal.h.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

We currently fully quiesce the ring before an unregister or update of
the fixed fileset. This is very expensive, and we can be a bit smarter
about this.

Add a percpu refcount for the file tables as a whole. Grab a percpu ref
when we use a registered file, and put it on completion. This is cheap
to do. Upon removal of a file from a set, switch the ref count to atomic
mode. When we hit zero ref on the completion side, then we know we can
drop the previously registered files. When the old files have been
dropped, switch the ref back to percpu mode for normal operation.

Since there's a period between doing the update and the kernel being
done with it, add a IORING_OP_FILES_UPDATE opcode that can perform the
same action. The application knows the update has completed when it gets
the CQE for it. Between doing the update and receiving this completion,
the application must continue to use the unregistered fd if submitting
IO on this particular file.

This takes the runtime of test/file-register from liburing from 14s to
about 0.7s.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 214828962dead0c698f92b60ef97ce3c5fc2c8fe upstream.

Percpu reference counters should now be initialized with the
PERCPU_REF_ALLOW_REINIT in order to allow switching them to the
percpu mode from the atomic mode. This is exactly what
percpu_ref_reinit() called from __io_uring_register() is supposed to
do. So let's initialize percpu refcounters with the
PERCU_REF_ALLOW_REINIT flag.
Signed-off-by: NRoman Gushchin <guro@fb.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NDennis Zhou <dennis@kernel.org>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

to #26323588

commit 7d9ab9b6adffd9c474c1274acb5f6208f9a09cf3 upstream.

Release percpu memory after finishing the switch to the atomic mode
if only PERCPU_REF_ALLOW_REINIT isn't set.
Signed-off-by: NRoman Gushchin <guro@fb.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NDennis Zhou <dennis@kernel.org>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>