The code to stack blk-mq drivers is only used by dm-multipath, and
will preferably stay that way.  Make it optional and only selected
by device mapper, so that the buildbots more easily catch abuses
like the one that slipped in in the ufs driver in the last merged
window.  Another positive side effects is that kernel builds without
device mapper shrink a little bit as well.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220215100540.3892965-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Don't need to do blkg_iostat_set for top blkg iostat on each CPU,
so move it after percpu stat aggregation.

Fixes: ef45fe47 ("blk-cgroup: show global disk stats in root cgroup io.stat")
Signed-off-by: NChengming Zhou <zhouchengming@bytedance.com>
Acked-by: NTejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220213085902.88884-1-zhouchengming@bytedance.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Based on the comment present in the bdev_get_queue()
bdev->bd_queue can never be NULL. Remove the NULL check for the local
variable q that is set from bdev_get_queue() for discard, write_same,
and write_zeroes.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220215115247.11717-2-kch@nvidia.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Partition include/linux/blk-cgroup.h into two parts: one is public part,
the other is block layer private part.

Suggested by Christoph Hellwig.
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220211101149.2368042-4-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

q->blkg_list is only used by blkcg code, so move it into
blkcg_init_queue.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220211101149.2368042-3-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Currently, rasdaemon uses the existing tracepoint block_rq_complete
and filters out non-error cases in order to capture block disk errors.

But there are a few problems with this approach:

1. Even kernel trace filter could do the filtering work, there is
   still some overhead after we enable this tracepoint.

2. The filter is merely based on errno, which does not align with kernel
   logic to check the errors for print_req_error().

3. block_rq_complete only provides dev major and minor to identify
   the block device, it is not convenient to use in user-space.

So introduce a new tracepoint block_rq_error just for the error case.
With this patch, rasdaemon could switch to block_rq_error.

Since the new tracepoint has the similar implementation with
block_rq_complete, so move the existing code from TRACE_EVENT
block_rq_complete() into new event class block_rq_completion(). Then add
event for block_rq_complete and block_rq_err respectively from the newly
created event class per the suggestion from Chaitanya Kulkarni.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: NYang Shi <shy828301@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220210225222.260069-1-shy828301@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Since __sbitmap_queue_get_shallow() was introduced in commit c05e6673
("sbitmap: add sbitmap_get_shallow() operation"), it has not been used.

Delete __sbitmap_queue_get_shallow() and rename public
__sbitmap_queue_get_shallow() -> sbitmap_queue_get_shallow() as it is odd
to have public __foo but no foo at all.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1644322024-105340-1-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass a block_device to bio_clone_fast and __bio_clone_fast and give
the functions more suitable names.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

All callers of __bio_clone_fast initialize the bio first.  Move that
initialization into __bio_clone_fast instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-13-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

__bio_clone_fast should also clone integrity and crypto data, as a clone
without those is incomplete.  Right now the only caller that can actually
support crypto and integrity data (dm) does it manually for the one
callchain that supports these, but we better do it properly in the core.

Note that all callers except for the above mentioned one also don't need
to handle failure at all, given that the integrity and crypto clones are
based on mempool allocations that won't fail for sleeping allocations.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-11-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Call bio_associate_blkg just like bio_set_dev did in the callers before
the conversion to set the block device in bio_reset.

Fixes: a7c50c94 ("block: pass a block_device and opf to bio_reset")
Reported-by: syzbot+2b3f18414c37b42dcc94@syzkaller.appspotmail.com
Tested-by: syzbot+2b3f18414c37b42dcc94@syzkaller.appspotmail.com
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220204071934.168469-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Change the user visible return value for BLK_STS_OFFLINE to -ENODEV, which
is more descriptive than existing -EIO.
Signed-off-by: NSong Liu <song@kernel.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220203192827.1370270-3-song@kernel.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

Currently, drivers reports BLK_STS_IOERR for devices that are not full
online or being removed. This behavior could cause confusion for users,
as they are not really I/O errors from the device.

Solve this issue with a new state BLK_STS_OFFLINE, which reports "device
offline error" in dmesg instead of "I/O error".

EIO is intentionally kept to not change user visible return value.
Signed-off-by: NSong Liu <song@kernel.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220203192827.1370270-2-song@kernel.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

Return statements in functions returning bool should use true/false
instead of 1/0.

./block/bio.c:1081:9-10: WARNING: return of 0/1 in function
'bio_add_folio' with return type bool.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220128043454.68927-1-jiapeng.chong@linux.alibaba.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Rename blk_flush_plug to __blk_flush_plug and add a wrapper that includes
the NULL check instead of open coding that check everywhere.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220127070549.1377856-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device that we plan to use this bio for and the
operation to bio_reset to optimize the assigment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-20-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device that we plan to use this bio for and the
operation to bio_init to optimize the assignment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment.  NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc_kiocb to optimize the assigment.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-17-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc_bioset to optimize the assigment.  NULL/0 can be passed, both
for the passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-16-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

All callers need to set the block_device and operation, so lift that into
the common code.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220124091107.642561-15-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Keep blk_next_bio next to the core bio infrastructure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-14-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

There is no good reason to keep genhd.h separate from the main blkdev.h
header that includes it.  So fold the contents of genhd.h into blkdev.h
and remove genhd.h entirely.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

No need to have this declaration in a public header.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

No need to have these declarations in a public header.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Make the legacy dev_t based autoloading optional and add a deprecation
warning.  This kind of autoloading has ceased to be useful about 20 years
ago.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220104071647.164918-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

bio_start_io_acct_time() interface is like bio_start_io_acct() that
allows start_time to be passed in. This gives drivers the ability to
defer starting accounting until after IO is issued (but possibily not
entirely due to bio splitting).
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220128155841.39644-2-snitzer@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

If blk_mq_request_issue_directly() failed from
blk_insert_cloned_request(), the request will be accounted start.
Currently, blk_insert_cloned_request() is only called by dm, and such
request won't be accounted done by dm.

In normal path, io will be accounted start from blk_mq_bio_to_request(),
when the request is allocated, and such io will be accounted done from
__blk_mq_end_request_acct() whether it succeeded or failed. Thus add
blk_account_io_done() to fix the problem.
Signed-off-by: NYu Kuai <yukuai3@huawei.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220126012132.3111551-1-yukuai3@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

kobject_init_and_add() takes reference even when it fails.
According to the doc of kobject_init_and_add()

   If this function returns an error, kobject_put() must be called to
   properly clean up the memory associated with the object.

Fix this issue by adding kobject_put().
Callback function blk_ia_ranges_sysfs_release() in kobject_put()
can handle the pointer "iars" properly.

Fixes: a2247f19 ("block: Add independent access ranges support")
Signed-off-by: NMiaoqian Lin <linmq006@gmail.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220120101025.22411-1-linmq006@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Patch series "remove Xen tmem leftovers".

Since the removal of the Xen tmem driver in 2019, the cleancache hooks
are entirely unused, as are large parts of frontswap.  This series
against linux-next (with the folio changes included) removes
cleancaches, and cuts down frontswap to the bits actually used by zswap.

This patch (of 13):

The cleancache subsystem is unused since the removal of Xen tmem driver
in commit 814bbf49 ("xen: remove tmem driver").

[akpm@linux-foundation.org: remove now-unreachable code]

Link: https://lkml.kernel.org/r/20211224062246.1258487-1-hch@lst.de
Link: https://lkml.kernel.org/r/20211224062246.1258487-2-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A previous commit added this feature, but it inadvertently used the wrong
variable to show/store the setting from/to, victimized by copy/paste. Fix
it up so that the async_depth sysfs interface reads and writes from the
right setting.

Fixes: 07757588 ("block/mq-deadline: Reserve 25% of scheduler tags for synchronous requests")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215485Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

bio_truncate() clears the buffer outside of last block of bdev, however
current bio_truncate() is using the wrong offset of page. So it can
return the uninitialized data.

This happened when both of truncated/corrupted FS and userspace (via
bdev) are trying to read the last of bdev.

Reported-by: syzbot+ac94ae5f68b84197f41c@syzkaller.appspotmail.com
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/875yqt1c9g.fsf@mail.parknet.co.jpSigned-off-by: NJens Axboe <axboe@kernel.dk>

bio_clone_fast() sets the cloned bio to have the same ->bi_bdev as the
source bio. This means that when request-based dm called setup_clone(),
the cloned bio had its ->bi_bdev pointing to the dm device. After Commit
0b6e522c ("blk-mq: use ->bi_bdev for I/O accounting")
__blk_account_io_start() started using the request's ->bio->bi_bdev for
I/O accounting, if it was set. This caused IO going to the underlying
devices to use the dm device for their I/O accounting.

Set up the proper ->bi_bdev in blk_rq_prep_clone based on the whole
device bdev for the queue the request is cloned onto.

Fixes: 0b6e522c ("blk-mq: use ->bi_bdev for I/O accounting")
Reported-by: NBenjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
[hch: the commit message is mostly from a different patch from Benjamin]
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NBenjamin Marzinski <bmarzins@redhat.com>
Link: https://lore.kernel.org/r/20220118070444.1241739-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

srcu structure has to be cleanup via cleanup_srcu_struct(), so fix it.

Reported-by: syzbot+4f789823c1abc5accf13@syzkaller.appspotmail.com
Fixes: 704b914f ("blk-mq: move srcu from blk_mq_hw_ctx to request_queue")
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220111123401.520192-1-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The parameter "ret" should be zero when running to this line,
no need to set to zero again, remove it.
Signed-off-by: NGuoYong Zheng <zhenggy@chinatelecom.cn>
Link: https://lore.kernel.org/r/1642414957-6785-1-git-send-email-zhenggy@chinatelecom.cnSigned-off-by: NJens Axboe <axboe@kernel.dk>

cpumask_first() is a more effective analogue of 'next' version if n == -1
(which means start == 0). This patch replaces 'next' with 'first' where
things look trivial.

There's no cpumask_first_zero() function, so create it.
Signed-off-by: NYury Norov <yury.norov@gmail.com>
Tested-by: NWolfram Sang <wsa+renesas@sang-engineering.com>

In case of shared tags, there might be more than one hctx which
allocates from the same tags, and each hctx is limited to allocate at
most:
        hctx_max_depth = max((bt->sb.depth + users - 1) / users, 4U);

tag idle detection is lazy, and may be delayed for 30sec, so there
could be just one real active hctx(queue) but all others are actually
idle and still accounted as active because of the lazy idle detection.
Then if wake_batch is > hctx_max_depth, driver tag allocation may wait
forever on this real active hctx.

Fix this by recalculating wake_batch when inc or dec active_queues.

Fixes: 0d2602ca ("blk-mq: improve support for shared tags maps")
Suggested-by: NMing Lei <ming.lei@redhat.com>
Suggested-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NLaibin Qiu <qiulaibin@huawei.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220113025536.1479653-1-qiulaibin@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Commit cc9c884d ("block: call submit_bio_checks under q_usage_counter")
uses q_usage_counter to protect submit_bio_checks for avoiding IO after
disk is deleted by del_gendisk().

Turns out the protection isn't necessary, because once
blk_mq_freeze_queue_wait() in del_gendisk() returns:

1) all in-flight IO has been done

2) all new IO will be failed in __bio_queue_enter() because
   q_usage_counter is dead, and GD_DEAD is set

3) both disk and request queue instance are safe since caller of
submit_bio() guarantees that the disk can't be closed.

Once submit_bio_checks() needn't the protection of q_usage_counter, we can
move submit_bio_checks before calling blk_mq_submit_bio() and
->submit_bio(). With this change, we needn't to throttle queue with
holding one allocated request, then precise driver tag or request won't be
wasted in throttling. Meantime we can unify the bio check for both bio
based and request based driver.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220104134223.590803-1-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Commit 5fc11eeb ("block: open code create_task_io_context in
set_task_ioprio") introduces a needless assignment
'ioc = task->io_context', as the local variable ioc is not further
used before returning.

Even after the further fix, commit a957b612 ("block: fix error in
handling dead task for ioprio setting"), the assignment still remains
needless.

Drop this needless assignment in set_task_ioprio().

This code smell was identified with 'make clang-analyzer'.

Fixes: 5fc11eeb ("block: open code create_task_io_context in set_task_ioprio")
Signed-off-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211223125300.20691-1-lukas.bulwahn@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

John Garry reported a deadlock that occurs when trying to access a
runtime-suspended SATA device.  For obscure reasons, the rescan procedure
causes the link to be hard-reset, which disconnects the device.

The rescan tries to carry out a runtime resume when accessing the device.
scsi_rescan_device() holds the SCSI device lock and won't release it until
it can put commands onto the device's block queue.  This can't happen until
the queue is successfully runtime-resumed or the device is unregistered.
But the runtime resume fails because the device is disconnected, and
__scsi_remove_device() can't do the unregistration because it can't get the
device lock.

The best way to resolve this deadlock appears to be to allow the block
queue to start running again even after an unsuccessful runtime resume.
The idea is that the driver or the SCSI error handler will need to be able
to use the queue to resolve the runtime resume failure.

This patch removes the err argument to blk_post_runtime_resume() and makes
the routine act as though the resume was successful always.  This fixes the
deadlock.

Link: https://lore.kernel.org/r/1639999298-244569-4-git-send-email-chenxiang66@hisilicon.com
Fixes: e27829dc ("scsi: serialize ->rescan against ->remove")
Reported-and-tested-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>