<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/block, branch v6.8-rc2</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>block: Fix WARNING in _copy_from_iter</title>
<updated>2024-01-23T15:56:55+00:00</updated>
<author>
<name>Christian A. Ehrhardt</name>
<email>lk@c--e.de</email>
</author>
<published>2024-01-21T20:26:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=13f3956eb5681a4045a8dfdef48df5dc4d9f58a6'/>
<id>13f3956eb5681a4045a8dfdef48df5dc4d9f58a6</id>
<content type='text'>
Syzkaller reports a warning in _copy_from_iter because an
iov_iter is supposedly used in the wrong direction. The reason
is that syzcaller managed to generate a request with
a transfer direction of SG_DXFER_TO_FROM_DEV. This instructs
the kernel to copy user buffers into the kernel, read into
the copied buffers and then copy the data back to user space.

Thus the iovec is used in both directions.

Detect this situation in the block layer and construct a new
iterator with the correct direction for the copy-in.

Reported-by: syzbot+a532b03fdfee2c137666@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/0000000000009b92c10604d7a5e9@google.com/t/
Reported-by: syzbot+63dec323ac56c28e644f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/0000000000003faaa105f6e7c658@google.com/T/
Signed-off-by: Christian A. Ehrhardt &lt;lk@c--e.de&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20240121202634.275068-1-lk@c--e.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Syzkaller reports a warning in _copy_from_iter because an
iov_iter is supposedly used in the wrong direction. The reason
is that syzcaller managed to generate a request with
a transfer direction of SG_DXFER_TO_FROM_DEV. This instructs
the kernel to copy user buffers into the kernel, read into
the copied buffers and then copy the data back to user space.

Thus the iovec is used in both directions.

Detect this situation in the block layer and construct a new
iterator with the correct direction for the copy-in.

Reported-by: syzbot+a532b03fdfee2c137666@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/0000000000009b92c10604d7a5e9@google.com/t/
Reported-by: syzbot+63dec323ac56c28e644f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/0000000000003faaa105f6e7c658@google.com/T/
Signed-off-by: Christian A. Ehrhardt &lt;lk@c--e.de&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20240121202634.275068-1-lk@c--e.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: Move checking GENHD_FL_NO_PART to bdev_add_partition()</title>
<updated>2024-01-22T16:51:29+00:00</updated>
<author>
<name>Li Lingfeng</name>
<email>lilingfeng3@huawei.com</email>
</author>
<published>2024-01-18T13:04:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7777f47f2ea64efd1016262e7b59fab34adfb869'/>
<id>7777f47f2ea64efd1016262e7b59fab34adfb869</id>
<content type='text'>
Commit 1a721de8489f ("block: don't add or resize partition on the disk
with GENHD_FL_NO_PART") prevented all operations about partitions on disks
with GENHD_FL_NO_PART in blkpg_do_ioctl() since they are meaningless.
However, it changed error code in some scenarios. So move checking
GENHD_FL_NO_PART to bdev_add_partition() to eliminate impact.

Fixes: 1a721de8489f ("block: don't add or resize partition on the disk with GENHD_FL_NO_PART")
Reported-by: Allison Karlitskaya &lt;allison.karlitskaya@redhat.com&gt;
Closes: https://lore.kernel.org/all/CAOYeF9VsmqKMcQjo1k6YkGNujwN-nzfxY17N3F-CMikE1tYp+w@mail.gmail.com/
Signed-off-by: Li Lingfeng &lt;lilingfeng3@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Link: https://lore.kernel.org/r/20240118130401.792757-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 1a721de8489f ("block: don't add or resize partition on the disk
with GENHD_FL_NO_PART") prevented all operations about partitions on disks
with GENHD_FL_NO_PART in blkpg_do_ioctl() since they are meaningless.
However, it changed error code in some scenarios. So move checking
GENHD_FL_NO_PART to bdev_add_partition() to eliminate impact.

Fixes: 1a721de8489f ("block: don't add or resize partition on the disk with GENHD_FL_NO_PART")
Reported-by: Allison Karlitskaya &lt;allison.karlitskaya@redhat.com&gt;
Closes: https://lore.kernel.org/all/CAOYeF9VsmqKMcQjo1k6YkGNujwN-nzfxY17N3F-CMikE1tYp+w@mail.gmail.com/
Signed-off-by: Li Lingfeng &lt;lilingfeng3@huawei.com&gt;
Reviewed-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Link: https://lore.kernel.org/r/20240118130401.792757-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-6.8/block-2024-01-18' of git://git.kernel.dk/linux</title>
<updated>2024-01-19T02:22:40+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-01-19T02:22:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9d1694dc91ce7b80bc96d6d8eaf1a1eca668d847'/>
<id>9d1694dc91ce7b80bc96d6d8eaf1a1eca668d847</id>
<content type='text'>
Pull block fixes from Jens Axboe:

 - NVMe pull request via Keith:
      - tcp, fc, and rdma target fixes (Maurizio, Daniel, Hannes,
        Christoph)
      - discard fixes and improvements (Christoph)
      - timeout debug improvements (Keith, Max)
      - various cleanups (Daniel, Max, Giuxen)
      - trace event string fixes (Arnd)
      - shadow doorbell setup on reset fix (William)
      - a write zeroes quirk for SK Hynix (Jim)

 - MD pull request via Song:
      - Sparse warning since v6.0 (Bart)
      - /proc/mdstat regression since v6.7 (Yu Kuai)

 - Use symbolic error value (Christian)

 - IO Priority documentation update (Christian)

 - Fix for accessing queue limits without having entered the queue
   (Christoph, me)

 - Fix for loop dio support (Christoph)

 - Move null_blk off deprecated ida interface (Christophe)

 - Ensure nbd initializes full msghdr (Eric)

 - Fix for a regression with the folio conversion, which is now easier
   to hit because of an unrelated change (Matthew)

 - Remove redundant check in virtio-blk (Li)

 - Fix for a potential hang in sbitmap (Ming)

 - Fix for partial zone appending (Damien)

 - Misc changes and fixes (Bart, me, Kemeng, Dmitry)

* tag 'for-6.8/block-2024-01-18' of git://git.kernel.dk/linux: (45 commits)
  Documentation: block: ioprio: Update schedulers
  loop: fix the the direct I/O support check when used on top of block devices
  blk-mq: Remove the hctx 'run' debugfs attribute
  nbd: always initialize struct msghdr completely
  block: Fix iterating over an empty bio with bio_for_each_folio_all
  block: bio-integrity: fix kcalloc() arguments order
  virtio_blk: remove duplicate check if queue is broken in virtblk_done
  sbitmap: remove stale comment in sbq_calc_wake_batch
  block: Correct a documentation comment in blk-cgroup.c
  null_blk: Remove usage of the deprecated ida_simple_xx() API
  block: ensure we hold a queue reference when using queue limits
  blk-mq: rename blk_mq_can_use_cached_rq
  block: print symbolic error name instead of error code
  blk-mq: fix IO hang from sbitmap wakeup race
  nvmet-rdma: avoid circular locking dependency on install_queue()
  nvmet-tcp: avoid circular locking dependency on install_queue()
  nvme-pci: set doorbell config before unquiescing
  block: fix partial zone append completion handling in req_bio_endio()
  block/iocost: silence warning on 'last_period' potentially being unused
  md/raid1: Use blk_opf_t for read and write operations
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block fixes from Jens Axboe:

 - NVMe pull request via Keith:
      - tcp, fc, and rdma target fixes (Maurizio, Daniel, Hannes,
        Christoph)
      - discard fixes and improvements (Christoph)
      - timeout debug improvements (Keith, Max)
      - various cleanups (Daniel, Max, Giuxen)
      - trace event string fixes (Arnd)
      - shadow doorbell setup on reset fix (William)
      - a write zeroes quirk for SK Hynix (Jim)

 - MD pull request via Song:
      - Sparse warning since v6.0 (Bart)
      - /proc/mdstat regression since v6.7 (Yu Kuai)

 - Use symbolic error value (Christian)

 - IO Priority documentation update (Christian)

 - Fix for accessing queue limits without having entered the queue
   (Christoph, me)

 - Fix for loop dio support (Christoph)

 - Move null_blk off deprecated ida interface (Christophe)

 - Ensure nbd initializes full msghdr (Eric)

 - Fix for a regression with the folio conversion, which is now easier
   to hit because of an unrelated change (Matthew)

 - Remove redundant check in virtio-blk (Li)

 - Fix for a potential hang in sbitmap (Ming)

 - Fix for partial zone appending (Damien)

 - Misc changes and fixes (Bart, me, Kemeng, Dmitry)

* tag 'for-6.8/block-2024-01-18' of git://git.kernel.dk/linux: (45 commits)
  Documentation: block: ioprio: Update schedulers
  loop: fix the the direct I/O support check when used on top of block devices
  blk-mq: Remove the hctx 'run' debugfs attribute
  nbd: always initialize struct msghdr completely
  block: Fix iterating over an empty bio with bio_for_each_folio_all
  block: bio-integrity: fix kcalloc() arguments order
  virtio_blk: remove duplicate check if queue is broken in virtblk_done
  sbitmap: remove stale comment in sbq_calc_wake_batch
  block: Correct a documentation comment in blk-cgroup.c
  null_blk: Remove usage of the deprecated ida_simple_xx() API
  block: ensure we hold a queue reference when using queue limits
  blk-mq: rename blk_mq_can_use_cached_rq
  block: print symbolic error name instead of error code
  blk-mq: fix IO hang from sbitmap wakeup race
  nvmet-rdma: avoid circular locking dependency on install_queue()
  nvmet-tcp: avoid circular locking dependency on install_queue()
  nvme-pci: set doorbell config before unquiescing
  block: fix partial zone append completion handling in req_bio_endio()
  block/iocost: silence warning on 'last_period' potentially being unused
  md/raid1: Use blk_opf_t for read and write operations
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-mq: Remove the hctx 'run' debugfs attribute</title>
<updated>2024-01-17T21:16:34+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bvanassche@acm.org</email>
</author>
<published>2024-01-17T20:36:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=49e60333d743ae32db3bdde2f93bc818482dd741'/>
<id>49e60333d743ae32db3bdde2f93bc818482dd741</id>
<content type='text'>
Nobody uses the debugfs hctx 'run' attribute. Hence remove this
attribute and also the code that updates the corresponding member
variable.

Suggested-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Gabriel Ryan &lt;gabe@cs.columbia.edu&gt;
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20240117203609.4122520-1-bvanassche@acm.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Nobody uses the debugfs hctx 'run' attribute. Hence remove this
attribute and also the code that updates the corresponding member
variable.

Suggested-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Gabriel Ryan &lt;gabe@cs.columbia.edu&gt;
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20240117203609.4122520-1-bvanassche@acm.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: bio-integrity: fix kcalloc() arguments order</title>
<updated>2024-01-16T16:51:22+00:00</updated>
<author>
<name>Dmitry Antipov</name>
<email>dmantipov@yandex.ru</email>
</author>
<published>2024-01-16T14:34:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=be50df31c4e2a69f961a3bb759346d299eaa2b23'/>
<id>be50df31c4e2a69f961a3bb759346d299eaa2b23</id>
<content type='text'>
When compiling with gcc version 14.0.1 20240116 (experimental)
and W=1, I've noticed the following warning:

block/bio-integrity.c: In function 'bio_integrity_map_user':
block/bio-integrity.c:339:38: warning: 'kcalloc' sizes specified with 'sizeof'
in the earlier argument and not in the later argument [-Wcalloc-transposed-args]
  339 |                 bvec = kcalloc(sizeof(*bvec), nr_vecs, GFP_KERNEL);
      |                                      ^
block/bio-integrity.c:339:38: note: earlier argument should specify number of
elements, later size of each element

Since 'n' and 'size' arguments of 'kcalloc()' are multiplied to
calculate the final size, their actual order doesn't affect the
result and so this is not a bug. But it's still worth to fix it.

Fixes: 492c5d455969 ("block: bio-integrity: directly map user buffers")
Signed-off-by: Dmitry Antipov &lt;dmantipov@yandex.ru&gt;
Reviewed-by: Keith Busch &lt;kbusch@kernel.org&gt;
Link: https://lore.kernel.org/r/20240116143437.89060-1-dmantipov@yandex.ru
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When compiling with gcc version 14.0.1 20240116 (experimental)
and W=1, I've noticed the following warning:

block/bio-integrity.c: In function 'bio_integrity_map_user':
block/bio-integrity.c:339:38: warning: 'kcalloc' sizes specified with 'sizeof'
in the earlier argument and not in the later argument [-Wcalloc-transposed-args]
  339 |                 bvec = kcalloc(sizeof(*bvec), nr_vecs, GFP_KERNEL);
      |                                      ^
block/bio-integrity.c:339:38: note: earlier argument should specify number of
elements, later size of each element

Since 'n' and 'size' arguments of 'kcalloc()' are multiplied to
calculate the final size, their actual order doesn't affect the
result and so this is not a bug. But it's still worth to fix it.

Fixes: 492c5d455969 ("block: bio-integrity: directly map user buffers")
Signed-off-by: Dmitry Antipov &lt;dmantipov@yandex.ru&gt;
Reviewed-by: Keith Busch &lt;kbusch@kernel.org&gt;
Link: https://lore.kernel.org/r/20240116143437.89060-1-dmantipov@yandex.ru
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: Correct a documentation comment in blk-cgroup.c</title>
<updated>2024-01-15T14:23:38+00:00</updated>
<author>
<name>Nicky Chorley</name>
<email>ndchorley@gmail.com</email>
</author>
<published>2024-01-14T19:10:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=521277d12b5a75982d4f642d2ee22db8d7f986dd'/>
<id>521277d12b5a75982d4f642d2ee22db8d7f986dd</id>
<content type='text'>
Commit 99e603874366
("blk-cgroup: pass a gendisk to the blkg allocation helpers") changed
blkg_alloc() to take a struct gendisk instead of a struct request_queue,
but the documentation comment still referred to q.

So, update that comment to refer to disk instead and fix a typo.

Signed-off-by: Nicky Chorley &lt;ndchorley@gmail.com&gt;
Link: https://lore.kernel.org/r/20240114191056.6992-1-ndchorley@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 99e603874366
("blk-cgroup: pass a gendisk to the blkg allocation helpers") changed
blkg_alloc() to take a struct gendisk instead of a struct request_queue,
but the documentation comment still referred to q.

So, update that comment to refer to disk instead and fix a typo.

Signed-off-by: Nicky Chorley &lt;ndchorley@gmail.com&gt;
Link: https://lore.kernel.org/r/20240114191056.6992-1-ndchorley@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: ensure we hold a queue reference when using queue limits</title>
<updated>2024-01-13T04:09:42+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>axboe@kernel.dk</email>
</author>
<published>2024-01-12T16:12:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7b4f36cd22a65b750b4cb6ac14804fb7d6e6c67d'/>
<id>7b4f36cd22a65b750b4cb6ac14804fb7d6e6c67d</id>
<content type='text'>
q_usage_counter is the only thing preventing us from the limits changing
under us in __bio_split_to_limits, but blk_mq_submit_bio doesn't hold
it while calling into it.

Move the splitting inside the region where we know we've got a queue
reference. Ideally this could still remain a shared section of code, but
let's keep the fix simple and defer any refactoring here to later.

Reported-by: Christoph Hellwig &lt;hch@lst.de&gt;
Fixes: 900e08075202 ("block: move queue enter logic into blk_mq_submit_bio()")
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
q_usage_counter is the only thing preventing us from the limits changing
under us in __bio_split_to_limits, but blk_mq_submit_bio doesn't hold
it while calling into it.

Move the splitting inside the region where we know we've got a queue
reference. Ideally this could still remain a shared section of code, but
let's keep the fix simple and defer any refactoring here to later.

Reported-by: Christoph Hellwig &lt;hch@lst.de&gt;
Fixes: 900e08075202 ("block: move queue enter logic into blk_mq_submit_bio()")
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-mq: rename blk_mq_can_use_cached_rq</title>
<updated>2024-01-12T16:11:34+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2024-01-11T13:57:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=309ce6741430b5a7b5e85cd1a7569647f8d9dfa6'/>
<id>309ce6741430b5a7b5e85cd1a7569647f8d9dfa6</id>
<content type='text'>
blk_mq_can_use_cached_rq doesn't just check if we can use the request,
but also performs the work to actually use it.  Remove the _can in the
naming, and improve the comment describing the function.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20240111135705.2155518-2-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
blk_mq_can_use_cached_rq doesn't just check if we can use the request,
but also performs the work to actually use it.  Remove the _can in the
naming, and improve the comment describing the function.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20240111135705.2155518-2-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: print symbolic error name instead of error code</title>
<updated>2024-01-12T16:07:46+00:00</updated>
<author>
<name>Christian Heusel</name>
<email>christian@heusel.eu</email>
</author>
<published>2024-01-11T23:15:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=25c1772a0493463408489b1fae65cf77fe46cac1'/>
<id>25c1772a0493463408489b1fae65cf77fe46cac1</id>
<content type='text'>
Utilize the %pe print specifier to get the symbolic error name as a
string (i.e "-ENOMEM") in the log message instead of the error code to
increase its readablility.

This change was suggested in
https://lore.kernel.org/all/92972476-0b1f-4d0a-9951-af3fc8bc6e65@suswa.mountain/

Signed-off-by: Christian Heusel &lt;christian@heusel.eu&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Link: https://lore.kernel.org/r/20240111231521.1596838-1-christian@heusel.eu
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Utilize the %pe print specifier to get the symbolic error name as a
string (i.e "-ENOMEM") in the log message instead of the error code to
increase its readablility.

This change was suggested in
https://lore.kernel.org/all/92972476-0b1f-4d0a-9951-af3fc8bc6e65@suswa.mountain/

Signed-off-by: Christian Heusel &lt;christian@heusel.eu&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Link: https://lore.kernel.org/r/20240111231521.1596838-1-christian@heusel.eu
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-mq: fix IO hang from sbitmap wakeup race</title>
<updated>2024-01-12T15:48:46+00:00</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2024-01-12T12:26:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5266caaf5660529e3da53004b8b7174cab6374ed'/>
<id>5266caaf5660529e3da53004b8b7174cab6374ed</id>
<content type='text'>
In blk_mq_mark_tag_wait(), __add_wait_queue() may be re-ordered
with the following blk_mq_get_driver_tag() in case of getting driver
tag failure.

Then in __sbitmap_queue_wake_up(), waitqueue_active() may not observe
the added waiter in blk_mq_mark_tag_wait() and wake up nothing, meantime
blk_mq_mark_tag_wait() can't get driver tag successfully.

This issue can be reproduced by running the following test in loop, and
fio hang can be observed in &lt; 30min when running it on my test VM
in laptop.

	modprobe -r scsi_debug
	modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4
	dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename`
	fio --filename=/dev/"$dev" --direct=1 --rw=randrw --bs=4k --iodepth=1 \
       		--runtime=100 --numjobs=40 --time_based --name=test \
        	--ioengine=libaio

Fix the issue by adding one explicit barrier in blk_mq_mark_tag_wait(), which
is just fine in case of running out of tag.

Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Reported-by: Changhui Zhong &lt;czhong@redhat.com&gt;
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20240112122626.4181044-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In blk_mq_mark_tag_wait(), __add_wait_queue() may be re-ordered
with the following blk_mq_get_driver_tag() in case of getting driver
tag failure.

Then in __sbitmap_queue_wake_up(), waitqueue_active() may not observe
the added waiter in blk_mq_mark_tag_wait() and wake up nothing, meantime
blk_mq_mark_tag_wait() can't get driver tag successfully.

This issue can be reproduced by running the following test in loop, and
fio hang can be observed in &lt; 30min when running it on my test VM
in laptop.

	modprobe -r scsi_debug
	modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4
	dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename`
	fio --filename=/dev/"$dev" --direct=1 --rw=randrw --bs=4k --iodepth=1 \
       		--runtime=100 --numjobs=40 --time_based --name=test \
        	--ioengine=libaio

Fix the issue by adding one explicit barrier in blk_mq_mark_tag_wait(), which
is just fine in case of running out of tag.

Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Kemeng Shi &lt;shikemeng@huaweicloud.com&gt;
Reported-by: Changhui Zhong &lt;czhong@redhat.com&gt;
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20240112122626.4181044-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
</feed>
