Just use the %pg format specifier instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220713055317.1888500-6-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Just use the %pg format specifier instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220713055317.1888500-5-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Just use the %pg format specifier instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChristoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220713055317.1888500-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Just use the %pg format specifier instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220713055317.1888500-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Just use the %pg format specifier instead.  Also reformat the
printk statement to be more readable.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220713055317.1888500-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Call blk_cleanup_queue() in release code path for fixing request
queue leak.

Also for-5.20/block has cleaned up blk_cleanup_queue(), which is
basically merged to del_gendisk() if blk_mq_alloc_disk() is used
for allocating disk and queue.

However, ublk may not add disk in case of starting device failure, then
del_gendisk() won't be called when removing ublk device, so blk_mq_exit_queue
will not be callsed, and it can be bit hard to deal with this kind of
merge conflict.

Turns out ublk's queue/disk use model is very similar with scsi, so switch
to scsi's model by allocating disk and queue independently, then it can be
quite easy to handle v5.20 merge conflict by replacing blk_cleanup_queue
with blk_mq_destroy_queue.
Reported-by: NJens Axboe <axboe@kernel.dk>
Fixes: 71f28f31 ("ublk_drv: add io_uring based userspace block driver")
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220714103201.131648-1-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use task_work_add if it is available, since task_work_add can bring
up better performance, especially batching signaling ->ubq_daemon can
be done.

It is observed that task_work_add() can boost iops by +4% on random
4k io test. Also except for completing io command, all other code
paths are same with completing io command via
io_uring_cmd_complete_in_task.

Meantime add one flag of UBLK_F_URING_CMD_COMP_IN_TASK for comparing
the mode easily.
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220713140711.97356-3-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

This is the driver part of userspace block driver(ublk driver), the other
part is userspace daemon part(ublksrv)[1].

The two parts communicate by io_uring's IORING_OP_URING_CMD with one
shared cmd buffer for storing io command, and the buffer is read only for
ublksrv, each io command is indexed by io request tag directly, and is
written by ublk driver.

For example, when one READ io request is submitted to ublk block driver,
ublk driver stores the io command into cmd buffer first, then completes
one IORING_OP_URING_CMD for notifying ublksrv, and the URING_CMD is issued
to ublk driver beforehand by ublksrv for getting notification of any new
io request, and each URING_CMD is associated with one io request by tag.

After ublksrv gets the io command, it translates and handles the ublk io
request, such as, for the ublk-loop target, ublksrv translates the request
into same request on another file or disk, like the kernel loop block
driver. In ublksrv's implementation, the io is still handled by io_uring,
and share same ring with IORING_OP_URING_CMD command. When the target io
request is done, the same IORING_OP_URING_CMD is issued to ublk driver for
both committing io request result and getting future notification of new
io request.

Another thing done by ublk driver is to copy data between kernel io
request and ublksrv's io buffer:

1) before ubsrv handles WRITE request, copy the request's data into
   ublksrv's userspace io buffer, so that ublksrv can handle the write
   request

2) after ubsrv handles READ request, copy ublksrv's userspace io buffer
   into this READ request, then ublk driver can complete the READ request

Zero copy may be switched if mm is ready to support it.

ublk driver doesn't handle any logic of the specific user space driver,
so it is small/simple enough.

[1] ublksrv

https://github.com/ming1/ubdsrvSigned-off-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220713140711.97356-2-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old
in blkcg_unuse_delay, blkcg_set_delay and blkcg_clear_delay and
atomic64_try_cmpxchg in blkcg_scale_delay.  x86 CMPXCHG instruction
returns success in ZF flag, so this change saves a compare after cmpxchg
(and related move instruction in front of cmpxchg).

Also, atomic_try_cmpxchg implicitly assigns old *ptr value to "old" when
cmpxchg fails, enabling further code simplifications.

No functional change intended.
Signed-off-by: NUros Bizjak <ubizjak@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20220712154455.66868-1-ubizjak@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old
in check_scale_change and atomic64_try_cmpxchg in blkcg_iolatency_done_bio.
x86 CMPXCHG instruction returns success in ZF flag, so this change saves a
compare after cmpxchg (and related move instruction in front of cmpxchg).

No functional change intended.
Signed-off-by: NUros Bizjak <ubizjak@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20220712151947.6783-1-ubizjak@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
update_io_ticks. x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related
move instruction in front of cmpxchg).

No functional change intended.
Signed-off-by: NUros Bizjak <ubizjak@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20220712152741.7324-1-ubizjak@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old in
atomic_inc_below. x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related move instruction
in front of cmpxchg).

Also, atomic_try_cmpxchg implicitly assigns old *ptr value to "old" when
cmpxchg fails, enabling further code simplifications.

No functional change intended.
Signed-off-by: NUros Bizjak <ubizjak@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20220712150547.5786-1-ubizjak@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

blk_mq_debugfs_register_hctx() can be called by blk_mq_update_nr_hw_queues
when gendisk isn't added yet, such as nvme tcp.

Fixes the warning of 'debugfs: Directory 'hctx0' with parent '/' already present!'
which can be observed reliably when running blktests nvme/005.

Fixes: 6cfc0081 ("blk-mq: no need to check return value of debugfs_create functions")
Reported-by: NYi Zhang <yi.zhang@redhat.com>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Tested-by: NYi Zhang <yi.zhang@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220711090808.259682-1-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Move the zone related fields that are currently stored in
struct request_queue to struct gendisk as these are part of the highlevel
block layer API and are only used for non-passthrough I/O that requires
the gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-17-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Always use bdev_zone_sectors instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-16-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use the bdev based helpers where applicable and move the zoned_dev
into the scope where it is actually used.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-15-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use the bdev based helpers instead of the queue based ones to clean up
the code a bit and prepare for storing all zone related fields in
struct gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-14-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use the bdev based helpers instead of the queue based ones to clean up
the code a bit and prepare for storing all zone related fields in
struct gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-13-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass a block_device instead of a request_queue as that is what most
callers have at hand.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-12-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Switch to a gendisk based API in preparation for moving all zone related
fields from the request_queue to the gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-11-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Always use the bdev based helpers instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-10-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Switch to a gendisk based API in preparation for moving all zone related
fields from the request_queue to the gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-9-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Switch to a gendisk based API in preparation for moving all zone related
fields from the request_queue to the gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-8-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Prepare for storing the zone related field in struct gendisk instead
of struct request_queue.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-7-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use the bdev based helpers instead of open coding them.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-6-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Drop the unused q argument, and invert the check to move the exception
into a branch and the regular path as the normal return.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-5-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use bdev_is_zoned in all places where a block_device is available instead
of open coding it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The zone bitmaps are only used for non-passthrough I/O, so free them as
soon as the disk is released.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

It doesn't hurt to always have the blk_zone_cond_str prototype, and the
two inlines can also be defined unconditionally.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The local variable is now only referenced once so drop it.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/1657109034-206040-7-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

We no longer use the 'reserved' arg in busy_tag_iter_fn for any iter
function so it may be dropped.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me> #nvme
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/1657109034-206040-6-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The SCSI core code does not support reserved requests, so drop the
handling in fnic_pending_aborts_iter().
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/1657109034-206040-5-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

With new API blk_mq_is_reserved_rq() we can tell if a request is from
the reserved pool, so stop passing 'reserved' arg. There is actually
only a single user of that arg for all the callback implementations, which
can use blk_mq_is_reserved_rq() instead.

This will also allow us to stop passing the same 'reserved' around the
blk-mq iter functions next.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/1657109034-206040-4-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add a flag for reserved requests so that drivers may know this for any
special handling.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/1657109034-206040-3-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The SCSI core code does not currently support reserved commands. As such,
requests which time-out would never be reserved, and scsi_timeout()
'reserved' arg should never be set.

Remove handling for reserved requests, drop the wrapper scsi_timeout()
as it now just calls scsi_times_out() always, and finally rename
scsi_times_out() -> scsi_timeout() to match the blk_mq_ops method name.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/1657109034-206040-2-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

To reduce some duplicated code, factor out blkcg_free_all_cpd(). No
functional change.
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220629070917.3113016-3-yanaijie@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

To reduce some duplicated code, factor out blkcg_iostat_update(). No
functional change.
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220629070917.3113016-2-yanaijie@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Lift setting disk->ia_ranges from disk_register_independent_access_ranges
into disk_set_independent_access_ranges, and make the behavior the same
for the registered vs non-registered queue cases.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220629062013.1331068-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Independent access ranges only matter for file system I/O and are only
valid with a registered gendisk, so move them there.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220629062013.1331068-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The configuration item BLK_RQ_IO_DATA_LEN is not declared in the kernel.
Select BLK_RQ_IO_DATA_LEN is meaningless which could be removed.
Signed-off-by: NYing Sun <sunying@nj.iscas.ac.cn>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220629062409.19458-1-sunying@nj.iscas.ac.cnSigned-off-by: NJens Axboe <axboe@kernel.dk>