<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/block/loop.c, branch v7.0-rc7</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>Convert 'alloc_obj' family to use the new default GFP_KERNEL argument</title>
<updated>2026-02-22T01:09:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-22T00:37:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43'/>
<id>bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43</id>
<content type='text'>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace kmalloc with kmalloc_obj for non-scalar types</title>
<updated>2026-02-21T09:02:28+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2026-02-21T07:49:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=69050f8d6d075dc01af7a5f2f550a8067510366f'/>
<id>69050f8d6d075dc01af7a5f2f550a8067510366f</id>
<content type='text'>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-7.0/block-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux</title>
<updated>2026-02-10T01:57:21+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-10T01:57:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0c00ed308d0559fc216be0442a3df124e9e13533'/>
<id>0c00ed308d0559fc216be0442a3df124e9e13533</id>
<content type='text'>
Pull block updates from Jens Axboe:

 - Support for batch request processing for ublk, improving the
   efficiency of the kernel/ublk server communication. This can yield
   nice 7-12% performance improvements

 - Support for integrity data for ublk

 - Various other ublk improvements and additions, including a ton of
   selftests additions and updated

 - Move the handling of blk-crypto software fallback from below the
   block layer to above it. This reduces the complexity of dealing with
   bio splitting

 - Series fixing a number of potential deadlocks in blk-mq related to
   the queue usage counter and writeback throttling and rq-qos debugfs
   handling

 - Add an async_depth queue attribute, to resolve a performance
   regression that's been around for a qhilw related to the scheduler
   depth handling

 - Only use task_work for IOPOLL completions on NVMe, if it is necessary
   to do so. An earlier fix for an issue resulted in all these
   completions being punted to task_work, to guarantee that completions
   were only run for a given io_uring ring when it was local to that
   ring. With the new changes, we can detect if it's necessary to use
   task_work or not, and avoid it if possible.

 - rnbd fixes:
      - Fix refcount underflow in device unmap path
      - Handle PREFLUSH and NOUNMAP flags properly in protocol
      - Fix server-side bi_size for special IOs
      - Zero response buffer before use
      - Fix trace format for flags
      - Add .release to rnbd_dev_ktype

 - MD pull requests via Yu Kuai
      - Fix raid5_run() to return error when log_init() fails
      - Fix IO hang with degraded array with llbitmap
      - Fix percpu_ref not resurrected on suspend timeout in llbitmap
      - Fix GPF in write_page caused by resize race
      - Fix NULL pointer dereference in process_metadata_update
      - Fix hang when stopping arrays with metadata through dm-raid
      - Fix any_working flag handling in raid10_sync_request
      - Refactor sync/recovery code path, improve error handling for
        badblocks, and remove unused recovery_disabled field
      - Consolidate mddev boolean fields into mddev_flags
      - Use mempool to allocate stripe_request_ctx and make sure
        max_sectors is not less than io_opt in raid5
      - Fix return value of mddev_trylock
      - Fix memory leak in raid1_run()
      - Add Li Nan as mdraid reviewer

 - Move phys_vec definitions to the kernel types, mostly in preparation
   for some VFIO and RDMA changes

 - Improve the speed for secure erase for some devices

 - Various little rust updates

 - Various other minor fixes, improvements, and cleanups

* tag 'for-7.0/block-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (162 commits)
  blk-mq: ABI/sysfs-block: fix docs build warnings
  selftests: ublk: organize test directories by test ID
  block: decouple secure erase size limit from discard size limit
  block: remove redundant kill_bdev() call in set_blocksize()
  blk-mq: add documentation for new queue attribute async_dpeth
  block, bfq: convert to use request_queue-&gt;async_depth
  mq-deadline: covert to use request_queue-&gt;async_depth
  kyber: covert to use request_queue-&gt;async_depth
  blk-mq: add a new queue sysfs attribute async_depth
  blk-mq: factor out a helper blk_mq_limit_depth()
  blk-mq-sched: unify elevators checking for async requests
  block: convert nr_requests to unsigned int
  block: don't use strcpy to copy blockdev name
  blk-mq-debugfs: warn about possible deadlock
  blk-mq-debugfs: add missing debugfs_mutex in blk_mq_debugfs_register_hctxs()
  blk-mq-debugfs: remove blk_mq_debugfs_unregister_rqos()
  blk-mq-debugfs: make blk_mq_debugfs_register_rqos() static
  blk-rq-qos: fix possible debugfs_mutex deadlock
  blk-mq-debugfs: factor out a helper to register debugfs for all rq_qos
  blk-wbt: fix possible deadlock to nest pcpu_alloc_mutex under q_usage_counter
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block updates from Jens Axboe:

 - Support for batch request processing for ublk, improving the
   efficiency of the kernel/ublk server communication. This can yield
   nice 7-12% performance improvements

 - Support for integrity data for ublk

 - Various other ublk improvements and additions, including a ton of
   selftests additions and updated

 - Move the handling of blk-crypto software fallback from below the
   block layer to above it. This reduces the complexity of dealing with
   bio splitting

 - Series fixing a number of potential deadlocks in blk-mq related to
   the queue usage counter and writeback throttling and rq-qos debugfs
   handling

 - Add an async_depth queue attribute, to resolve a performance
   regression that's been around for a qhilw related to the scheduler
   depth handling

 - Only use task_work for IOPOLL completions on NVMe, if it is necessary
   to do so. An earlier fix for an issue resulted in all these
   completions being punted to task_work, to guarantee that completions
   were only run for a given io_uring ring when it was local to that
   ring. With the new changes, we can detect if it's necessary to use
   task_work or not, and avoid it if possible.

 - rnbd fixes:
      - Fix refcount underflow in device unmap path
      - Handle PREFLUSH and NOUNMAP flags properly in protocol
      - Fix server-side bi_size for special IOs
      - Zero response buffer before use
      - Fix trace format for flags
      - Add .release to rnbd_dev_ktype

 - MD pull requests via Yu Kuai
      - Fix raid5_run() to return error when log_init() fails
      - Fix IO hang with degraded array with llbitmap
      - Fix percpu_ref not resurrected on suspend timeout in llbitmap
      - Fix GPF in write_page caused by resize race
      - Fix NULL pointer dereference in process_metadata_update
      - Fix hang when stopping arrays with metadata through dm-raid
      - Fix any_working flag handling in raid10_sync_request
      - Refactor sync/recovery code path, improve error handling for
        badblocks, and remove unused recovery_disabled field
      - Consolidate mddev boolean fields into mddev_flags
      - Use mempool to allocate stripe_request_ctx and make sure
        max_sectors is not less than io_opt in raid5
      - Fix return value of mddev_trylock
      - Fix memory leak in raid1_run()
      - Add Li Nan as mdraid reviewer

 - Move phys_vec definitions to the kernel types, mostly in preparation
   for some VFIO and RDMA changes

 - Improve the speed for secure erase for some devices

 - Various little rust updates

 - Various other minor fixes, improvements, and cleanups

* tag 'for-7.0/block-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (162 commits)
  blk-mq: ABI/sysfs-block: fix docs build warnings
  selftests: ublk: organize test directories by test ID
  block: decouple secure erase size limit from discard size limit
  block: remove redundant kill_bdev() call in set_blocksize()
  blk-mq: add documentation for new queue attribute async_dpeth
  block, bfq: convert to use request_queue-&gt;async_depth
  mq-deadline: covert to use request_queue-&gt;async_depth
  kyber: covert to use request_queue-&gt;async_depth
  blk-mq: add a new queue sysfs attribute async_depth
  blk-mq: factor out a helper blk_mq_limit_depth()
  blk-mq-sched: unify elevators checking for async requests
  block: convert nr_requests to unsigned int
  block: don't use strcpy to copy blockdev name
  blk-mq-debugfs: warn about possible deadlock
  blk-mq-debugfs: add missing debugfs_mutex in blk_mq_debugfs_register_hctxs()
  blk-mq-debugfs: remove blk_mq_debugfs_unregister_rqos()
  blk-mq-debugfs: make blk_mq_debugfs_register_rqos() static
  blk-rq-qos: fix possible debugfs_mutex deadlock
  blk-mq-debugfs: factor out a helper to register debugfs for all rq_qos
  blk-wbt: fix possible deadlock to nest pcpu_alloc_mutex under q_usage_counter
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>loop: revert exclusive opener loop status change</title>
<updated>2026-02-05T16:26:53+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>axboe@kernel.dk</email>
</author>
<published>2026-02-05T16:26:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a6abd64e145ca3084b6a567e06517a7c2dbfd38d'/>
<id>a6abd64e145ca3084b6a567e06517a7c2dbfd38d</id>
<content type='text'>
This commit effectively reverts the following two commits:

2704024d83fa ("loop: add missing bd_abort_claiming in loop_set_status")
08e136ebd193 ("loop: don't change loop device under exclusive opener in loop_set_status")

as there are reports of them causing issues with unmounting. As we're
close to the 6.19 kernel release and the original author hasn't taken a
closer look at this yet, revert them for release.

Reported-by: nokangaroo &lt;nokangaroo@aon.at&gt;
Link: https://lore.kernel.org/all/62de4453-17e8-47f6-a10b-39bf5a49fdee@leemhuis.info/
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This commit effectively reverts the following two commits:

2704024d83fa ("loop: add missing bd_abort_claiming in loop_set_status")
08e136ebd193 ("loop: don't change loop device under exclusive opener in loop_set_status")

as there are reports of them causing issues with unmounting. As we're
close to the 6.19 kernel release and the original author hasn't taken a
closer look at this yet, revert them for release.

Reported-by: nokangaroo &lt;nokangaroo@aon.at&gt;
Link: https://lore.kernel.org/all/62de4453-17e8-47f6-a10b-39bf5a49fdee@leemhuis.info/
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: introduce bdev_rot()</title>
<updated>2026-01-30T15:11:09+00:00</updated>
<author>
<name>Damien Le Moal</name>
<email>dlemoal@kernel.org</email>
</author>
<published>2026-01-30T06:28:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=da562d92e6755c00cd67845a8dbfb908dac51a9c'/>
<id>da562d92e6755c00cd67845a8dbfb908dac51a9c</id>
<content type='text'>
Introduce the helper function bdev_rot() to test if a block device is a
rotational one. The existing function bdev_nonrot() which tests for the
opposite condition is redefined using this new helper.
This avoids the double negation (operator and name) that appears when
testing if a block device is a rotational device, thus making the code a
little easier to read.

Call sites of bdev_nonrot() in the block layer are updated to use this
new helper.  Remaining users in other subsystems are left unchanged for
now.

Signed-off-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.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>
Introduce the helper function bdev_rot() to test if a block device is a
rotational one. The existing function bdev_nonrot() which tests for the
opposite condition is redefined using this new helper.
This avoids the double negation (operator and name) that appears when
testing if a block device is a rotational device, thus making the code a
little easier to read.

Call sites of bdev_nonrot() in the block layer are updated to use this
new helper.  Remaining users in other subsystems are left unchanged for
now.

Signed-off-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>loop: add missing bd_abort_claiming in loop_set_status</title>
<updated>2026-01-07T15:04:42+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2026-01-07T10:41:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2704024d83fa9eb8e5f16925aae340fd9d246694'/>
<id>2704024d83fa9eb8e5f16925aae340fd9d246694</id>
<content type='text'>
Commit 08e136ebd193 ("loop: don't change loop device under exclusive
opener in loop_set_status") forgot to call bd_abort_claiming() when
mutex_lock_killable() failed.

Fixes: 08e136ebd193 ("loop: don't change loop device under exclusive opener in loop_set_status")
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 08e136ebd193 ("loop: don't change loop device under exclusive
opener in loop_set_status") forgot to call bd_abort_claiming() when
mutex_lock_killable() failed.

Fixes: 08e136ebd193 ("loop: don't change loop device under exclusive opener in loop_set_status")
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>loop: don't change loop device under exclusive opener in loop_set_status</title>
<updated>2026-01-06T12:30:18+00:00</updated>
<author>
<name>Raphael Pinsonneault-Thibeault</name>
<email>rpthibeault@gmail.com</email>
</author>
<published>2025-12-17T19:00:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=08e136ebd193eae7d5eff4c66d576c4a2dabdc3f'/>
<id>08e136ebd193eae7d5eff4c66d576c4a2dabdc3f</id>
<content type='text'>
loop_set_status() is allowed to change the loop device while there
are other openers of the device, even exclusive ones.

In this case, it causes a KASAN: slab-out-of-bounds Read in
ext4_search_dir(), since when looking for an entry in an inlined
directory, e_value_offs is changed underneath the filesystem by
loop_set_status().

Fix the problem by forbidding loop_set_status() from modifying the loop
device while there are exclusive openers of the device. This is similar
to the fix in loop_configure() by commit 33ec3e53e7b1 ("loop: Don't
change loop device under exclusive opener") alongside commit ecbe6bc0003b
("block: use bd_prepare_to_claim directly in the loop driver").

Reported-by: syzbot+3ee481e21fd75e14c397@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=3ee481e21fd75e14c397
Tested-by: syzbot+3ee481e21fd75e14c397@syzkaller.appspotmail.com
Tested-by: Yongpeng Yang &lt;yangyongpeng@xiaomi.com&gt;
Signed-off-by: Raphael Pinsonneault-Thibeault &lt;rpthibeault@gmail.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
loop_set_status() is allowed to change the loop device while there
are other openers of the device, even exclusive ones.

In this case, it causes a KASAN: slab-out-of-bounds Read in
ext4_search_dir(), since when looking for an entry in an inlined
directory, e_value_offs is changed underneath the filesystem by
loop_set_status().

Fix the problem by forbidding loop_set_status() from modifying the loop
device while there are exclusive openers of the device. This is similar
to the fix in loop_configure() by commit 33ec3e53e7b1 ("loop: Don't
change loop device under exclusive opener") alongside commit ecbe6bc0003b
("block: use bd_prepare_to_claim directly in the loop driver").

Reported-by: syzbot+3ee481e21fd75e14c397@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=3ee481e21fd75e14c397
Tested-by: syzbot+3ee481e21fd75e14c397@syzkaller.appspotmail.com
Tested-by: Yongpeng Yang &lt;yangyongpeng@xiaomi.com&gt;
Signed-off-by: Raphael Pinsonneault-Thibeault &lt;rpthibeault@gmail.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>loop: use READ_ONCE() to read lo-&gt;lo_state without locking</title>
<updated>2025-12-15T16:32:42+00:00</updated>
<author>
<name>Yongpeng Yang</name>
<email>yangyongpeng@xiaomi.com</email>
</author>
<published>2025-12-15T15:21:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=54891a96b7a90d77c32bd0a7d6c9987e5479a314'/>
<id>54891a96b7a90d77c32bd0a7d6c9987e5479a314</id>
<content type='text'>
When lo-&gt;lo_mutex is not held, direct access may read stale data. This
patch uses READ_ONCE() to read lo-&gt;lo_state and data_race() to silence
code checkers, and changes all assignments to use WRITE_ONCE().

Reviewed-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Signed-off-by: Yongpeng Yang &lt;yangyongpeng@xiaomi.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When lo-&gt;lo_mutex is not held, direct access may read stale data. This
patch uses READ_ONCE() to read lo-&gt;lo_state and data_race() to silence
code checkers, and changes all assignments to use WRITE_ONCE().

Reviewed-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Signed-off-by: Yongpeng Yang &lt;yangyongpeng@xiaomi.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-mq: add blk_rq_nr_bvec() helper</title>
<updated>2025-12-04T14:19:26+00:00</updated>
<author>
<name>Chaitanya Kulkarni</name>
<email>ckulkarnilinux@gmail.com</email>
</author>
<published>2025-12-03T03:58:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=71075d25ca5cae732fb57da065fbf14aeb3bcfc7'/>
<id>71075d25ca5cae732fb57da065fbf14aeb3bcfc7</id>
<content type='text'>
Add a new helper function blk_rq_nr_bvec() that returns the number of
bvecs in a request. This count represents the number of iterations
rq_for_each_bvec() would perform on a request.

Drivers need to pre-allocate bvec arrays before iterating through
a request's bvecs. Currently, they manually count bvecs using
rq_for_each_bvec() in a loop, which is repetitive. The new helper
centralizes this logic.

This pattern exists in loop and zloop drivers, where multi-bio requests
require copying bvecs into a contiguous array before creating
an iov_iter for file operations.

Update loop and zloop drivers to use the new helper, eliminating
duplicate code.

This patch also provides a clear API to avoid any potential misuse of
blk_nr_phys_segments() for calculating the bvecs since, one bvec can
have more than one segments and use of blk_nr_phys_segments() can
lead to extra memory allocation :-

[ 6155.673749] nullb_bio: 128K bio as ONE bvec: sector=0, size=131072
[ 6155.673846] null_blk: #### null_handle_data_transfer:1375
[ 6155.673850] null_blk: nr_bvec=1 blk_rq_nr_phys_segments=2
[ 6155.674263] null_blk: #### null_handle_data_transfer:1375
[ 6155.674267] null_blk: nr_bvec=1 blk_rq_nr_phys_segments=1

Reviewed-by: Niklas Cassel &lt;cassel@kernel.org&gt;
Signed-off-by: Chaitanya Kulkarni &lt;ckulkarnilinux@gmail.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a new helper function blk_rq_nr_bvec() that returns the number of
bvecs in a request. This count represents the number of iterations
rq_for_each_bvec() would perform on a request.

Drivers need to pre-allocate bvec arrays before iterating through
a request's bvecs. Currently, they manually count bvecs using
rq_for_each_bvec() in a loop, which is repetitive. The new helper
centralizes this logic.

This pattern exists in loop and zloop drivers, where multi-bio requests
require copying bvecs into a contiguous array before creating
an iov_iter for file operations.

Update loop and zloop drivers to use the new helper, eliminating
duplicate code.

This patch also provides a clear API to avoid any potential misuse of
blk_nr_phys_segments() for calculating the bvecs since, one bvec can
have more than one segments and use of blk_nr_phys_segments() can
lead to extra memory allocation :-

[ 6155.673749] nullb_bio: 128K bio as ONE bvec: sector=0, size=131072
[ 6155.673846] null_blk: #### null_handle_data_transfer:1375
[ 6155.673850] null_blk: nr_bvec=1 blk_rq_nr_phys_segments=2
[ 6155.674263] null_blk: #### null_handle_data_transfer:1375
[ 6155.674267] null_blk: nr_bvec=1 blk_rq_nr_phys_segments=1

Reviewed-by: Niklas Cassel &lt;cassel@kernel.org&gt;
Signed-off-by: Chaitanya Kulkarni &lt;ckulkarnilinux@gmail.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "Merge branch 'loop-aio-nowait' into for-6.19/block"</title>
<updated>2025-11-25T03:53:19+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>axboe@kernel.dk</email>
</author>
<published>2025-11-25T03:53:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=96f03c8cb29f2ec5ffe8e24fbec2c64f3c3bf4e5'/>
<id>96f03c8cb29f2ec5ffe8e24fbec2c64f3c3bf4e5</id>
<content type='text'>
This reverts commit f43fdeb9a368a5ff56b088b46edc245bd4b52cde, reversing
changes made to 2c6d792d4b7676e2b340df05425330452fee1f40.

There are concerns that doing inline submits can cause excessive
stack usage, particularly when going back into the filesystem. Revert
the loop dio nowait change for now.

Link: https://lore.kernel.org/linux-block/aSP3SG_KaROJTBHx@infradead.org/
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit f43fdeb9a368a5ff56b088b46edc245bd4b52cde, reversing
changes made to 2c6d792d4b7676e2b340df05425330452fee1f40.

There are concerns that doing inline submits can cause excessive
stack usage, particularly when going back into the filesystem. Revert
the loop dio nowait change for now.

Link: https://lore.kernel.org/linux-block/aSP3SG_KaROJTBHx@infradead.org/
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
</feed>
