<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/block, branch v6.1.55</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>block: factor out a bvec_set_page helper</title>
<updated>2023-09-23T09:11:08+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2023-02-03T15:06:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00cf1dc13c1f5207693abe59d6e26d8fd0ed7673'/>
<id>00cf1dc13c1f5207693abe59d6e26d8fd0ed7673</id>
<content type='text'>
[ Upstream commit d58cdfae6a22e5079656c487aad669597a0635c8 ]

Add a helper to initialize a bvec based of a page pointer.  This will help
removing various open code bvec initializations.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20230203150634.3199647-2-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 1f0bbf28940c ("nvmet-tcp: pass iov_len instead of sg-&gt;length to bvec_set_page()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d58cdfae6a22e5079656c487aad669597a0635c8 ]

Add a helper to initialize a bvec based of a page pointer.  This will help
removing various open code bvec initializations.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20230203150634.3199647-2-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 1f0bbf28940c ("nvmet-tcp: pass iov_len instead of sg-&gt;length to bvec_set_page()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-throttle: consider 'carryover_ios/bytes' in throtl_trim_slice()</title>
<updated>2023-09-19T10:28:00+00:00</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2023-08-16T01:27:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=84d577923450827997ef19015591bc1bfd0aef0f'/>
<id>84d577923450827997ef19015591bc1bfd0aef0f</id>
<content type='text'>
[ Upstream commit eead0056648cef49d7b15c07ae612fa217083165 ]

Currently, 'carryover_ios/bytes' is not handled in throtl_trim_slice(),
for consequence, 'carryover_ios/bytes' will be used to throttle bio
multiple times, for example:

1) set iops limit to 100, and slice start is 0, slice end is 100ms;
2) current time is 0, and 10 ios are dispatched, those io won't be
   throttled and io_disp is 10;
3) still at current time 0, update iops limit to 1000, carryover_ios is
   updated to (0 - 10) = -10;
4) in this slice(0 - 100ms), io_allowed = 100 + (-10) = 90, which means
   only 90 ios can be dispatched without waiting;
5) assume that io is throttled in slice(0 - 100ms), and
   throtl_trim_slice() update silce to (100ms - 200ms). In this case,
   'carryover_ios/bytes' is not cleared and still only 90 ios can be
   dispatched between 100ms - 200ms.

Fix this problem by updating 'carryover_ios/bytes' in
throtl_trim_slice().

Fixes: a880ae93e5b5 ("blk-throttle: fix io hung due to configuration updates")
Reported-by: zhuxiaohui &lt;zhuxiaohui.400@bytedance.com&gt;
Link: https://lore.kernel.org/all/20230812072116.42321-1-zhuxiaohui.400@bytedance.com/
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Link: https://lore.kernel.org/r/20230816012708.1193747-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit eead0056648cef49d7b15c07ae612fa217083165 ]

Currently, 'carryover_ios/bytes' is not handled in throtl_trim_slice(),
for consequence, 'carryover_ios/bytes' will be used to throttle bio
multiple times, for example:

1) set iops limit to 100, and slice start is 0, slice end is 100ms;
2) current time is 0, and 10 ios are dispatched, those io won't be
   throttled and io_disp is 10;
3) still at current time 0, update iops limit to 1000, carryover_ios is
   updated to (0 - 10) = -10;
4) in this slice(0 - 100ms), io_allowed = 100 + (-10) = 90, which means
   only 90 ios can be dispatched without waiting;
5) assume that io is throttled in slice(0 - 100ms), and
   throtl_trim_slice() update silce to (100ms - 200ms). In this case,
   'carryover_ios/bytes' is not cleared and still only 90 ios can be
   dispatched between 100ms - 200ms.

Fix this problem by updating 'carryover_ios/bytes' in
throtl_trim_slice().

Fixes: a880ae93e5b5 ("blk-throttle: fix io hung due to configuration updates")
Reported-by: zhuxiaohui &lt;zhuxiaohui.400@bytedance.com&gt;
Link: https://lore.kernel.org/all/20230812072116.42321-1-zhuxiaohui.400@bytedance.com/
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Link: https://lore.kernel.org/r/20230816012708.1193747-5-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-throttle: use calculate_io/bytes_allowed() for throtl_trim_slice()</title>
<updated>2023-09-19T10:28:00+00:00</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2023-08-16T01:27:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fd2420905c8ede1967bca335adde6af4a8d4a49e'/>
<id>fd2420905c8ede1967bca335adde6af4a8d4a49e</id>
<content type='text'>
[ Upstream commit e8368b57c006dc0e02dcd8a9dc9f2060ff5476fe ]

There are no functional changes, just make the code cleaner.

Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Link: https://lore.kernel.org/r/20230816012708.1193747-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: eead0056648c ("blk-throttle: consider 'carryover_ios/bytes' in throtl_trim_slice()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e8368b57c006dc0e02dcd8a9dc9f2060ff5476fe ]

There are no functional changes, just make the code cleaner.

Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Link: https://lore.kernel.org/r/20230816012708.1193747-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: eead0056648c ("blk-throttle: consider 'carryover_ios/bytes' in throtl_trim_slice()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: don't add or resize partition on the disk with GENHD_FL_NO_PART</title>
<updated>2023-09-13T07:43:02+00:00</updated>
<author>
<name>Li Lingfeng</name>
<email>lilingfeng3@huawei.com</email>
</author>
<published>2023-08-31T07:59:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5e4e9900e6fa61302c26d028830b271997bf329f'/>
<id>5e4e9900e6fa61302c26d028830b271997bf329f</id>
<content type='text'>
commit 1a721de8489fa559ff4471f73c58bb74ac5580d3 upstream.

Commit a33df75c6328 ("block: use an xarray for disk-&gt;part_tbl") remove
disk_expand_part_tbl() in add_partition(), which means all kinds of
devices will support extended dynamic `dev_t`.
However, some devices with GENHD_FL_NO_PART are not expected to add or
resize partition.
Fix this by adding check of GENHD_FL_NO_PART before add or resize
partition.

Fixes: a33df75c6328 ("block: use an xarray for disk-&gt;part_tbl")
Signed-off-by: Li Lingfeng &lt;lilingfeng3@huawei.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230831075900.1725842-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1a721de8489fa559ff4471f73c58bb74ac5580d3 upstream.

Commit a33df75c6328 ("block: use an xarray for disk-&gt;part_tbl") remove
disk_expand_part_tbl() in add_partition(), which means all kinds of
devices will support extended dynamic `dev_t`.
However, some devices with GENHD_FL_NO_PART are not expected to add or
resize partition.
Fix this by adding check of GENHD_FL_NO_PART before add or resize
partition.

Fixes: a33df75c6328 ("block: use an xarray for disk-&gt;part_tbl")
Signed-off-by: Li Lingfeng &lt;lilingfeng3@huawei.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230831075900.1725842-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block/mq-deadline: use correct way to throttling write requests</title>
<updated>2023-09-13T07:42:42+00:00</updated>
<author>
<name>Zhiguo Niu</name>
<email>zhiguo.niu@unisoc.com</email>
</author>
<published>2023-08-03T11:12:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9183c4fe9141e6575c801aad2d9fa23b4855d763'/>
<id>9183c4fe9141e6575c801aad2d9fa23b4855d763</id>
<content type='text'>
[ Upstream commit d47f9717e5cfd0dd8c0ba2ecfa47c38d140f1bb6 ]

The original formula was inaccurate:
dd-&gt;async_depth = max(1UL, 3 * q-&gt;nr_requests / 4);

For write requests, when we assign a tags from sched_tags,
data-&gt;shallow_depth will be passed to sbitmap_find_bit,
see the following code:

nr = sbitmap_find_bit_in_word(&amp;sb-&gt;map[index],
			min_t (unsigned int,
			__map_depth(sb, index),
			depth),
			alloc_hint, wrap);

The smaller of data-&gt;shallow_depth and __map_depth(sb, index)
will be used as the maximum range when allocating bits.

For a mmc device (one hw queue, deadline I/O scheduler):
q-&gt;nr_requests = sched_tags = 128, so according to the previous
calculation method, dd-&gt;async_depth = data-&gt;shallow_depth = 96,
and the platform is 64bits with 8 cpus, sched_tags.bitmap_tags.sb.shift=5,
sb.maps[]=32/32/32/32, 32 is smaller than 96, whether it is a read or
a write I/O, tags can be allocated to the maximum range each time,
which has not throttling effect.

In addition, refer to the methods of bfg/kyber I/O scheduler,
limit ratiois are calculated base on sched_tags.bitmap_tags.sb.shift.

This patch can throttle write requests really.

Fixes: 07757588e507 ("block/mq-deadline: Reserve 25% of scheduler tags for synchronous requests")

Signed-off-by: Zhiguo Niu &lt;zhiguo.niu@unisoc.com&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/1691061162-22898-1-git-send-email-zhiguo.niu@unisoc.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d47f9717e5cfd0dd8c0ba2ecfa47c38d140f1bb6 ]

The original formula was inaccurate:
dd-&gt;async_depth = max(1UL, 3 * q-&gt;nr_requests / 4);

For write requests, when we assign a tags from sched_tags,
data-&gt;shallow_depth will be passed to sbitmap_find_bit,
see the following code:

nr = sbitmap_find_bit_in_word(&amp;sb-&gt;map[index],
			min_t (unsigned int,
			__map_depth(sb, index),
			depth),
			alloc_hint, wrap);

The smaller of data-&gt;shallow_depth and __map_depth(sb, index)
will be used as the maximum range when allocating bits.

For a mmc device (one hw queue, deadline I/O scheduler):
q-&gt;nr_requests = sched_tags = 128, so according to the previous
calculation method, dd-&gt;async_depth = data-&gt;shallow_depth = 96,
and the platform is 64bits with 8 cpus, sched_tags.bitmap_tags.sb.shift=5,
sb.maps[]=32/32/32/32, 32 is smaller than 96, whether it is a read or
a write I/O, tags can be allocated to the maximum range each time,
which has not throttling effect.

In addition, refer to the methods of bfg/kyber I/O scheduler,
limit ratiois are calculated base on sched_tags.bitmap_tags.sb.shift.

This patch can throttle write requests really.

Fixes: 07757588e507 ("block/mq-deadline: Reserve 25% of scheduler tags for synchronous requests")

Signed-off-by: Zhiguo Niu &lt;zhiguo.niu@unisoc.com&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/1691061162-22898-1-git-send-email-zhiguo.niu@unisoc.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: don't allow enabling a cache on devices that don't support it</title>
<updated>2023-09-13T07:42:40+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2023-07-07T09:42:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00c0b2825bb5df26c339cef1d32db6a8755de203'/>
<id>00c0b2825bb5df26c339cef1d32db6a8755de203</id>
<content type='text'>
[ Upstream commit 43c9835b144c7ce29efe142d662529662a9eb376 ]

Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC
flag on devices that never claimed the capability.

Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by
blk_queue_write_cache and guards re-enabling the cache through sysfs.

Note that any rescan that calls blk_queue_write_cache will still
re-enable the write cache as in the current code.

Fixes: 93e9d8e836cb ("block: add ability to flag write back caching on a device")
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 43c9835b144c7ce29efe142d662529662a9eb376 ]

Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC
flag on devices that never claimed the capability.

Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by
blk_queue_write_cache and guards re-enabling the cache through sysfs.

Note that any rescan that calls blk_queue_write_cache will still
re-enable the write cache as in the current code.

Fixes: 93e9d8e836cb ("block: add ability to flag write back caching on a device")
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: cleanup queue_wc_store</title>
<updated>2023-09-13T07:42:39+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2023-07-07T09:42:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e5e0ec8ff16089a0801cd6a1748003697b6b901f'/>
<id>e5e0ec8ff16089a0801cd6a1748003697b6b901f</id>
<content type='text'>
[ Upstream commit c4e21bcd0f9d01f9c5d6c52007f5541871a5b1de ]

Get rid of the local queue_wc_store variable and handling setting and
clearing the QUEUE_FLAG_WC flag diretly instead the if / else if.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230707094239.107968-2-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 43c9835b144c ("block: don't allow enabling a cache on devices that don't support it")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c4e21bcd0f9d01f9c5d6c52007f5541871a5b1de ]

Get rid of the local queue_wc_store variable and handling setting and
clearing the QUEUE_FLAG_WC flag diretly instead the if / else if.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230707094239.107968-2-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 43c9835b144c ("block: don't allow enabling a cache on devices that don't support it")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-crypto: dynamically allocate fallback profile</title>
<updated>2023-08-23T15:52:39+00:00</updated>
<author>
<name>Sweet Tea Dorminy</name>
<email>sweettea-kernel@dorminy.me</email>
</author>
<published>2023-08-17T14:15:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8ad3bfdd227e0f644e0c528c9d80d108a74c0f0f'/>
<id>8ad3bfdd227e0f644e0c528c9d80d108a74c0f0f</id>
<content type='text'>
commit c984ff1423ae9f70b1f28ce811856db0d9c99021 upstream.

blk_crypto_profile_init() calls lockdep_register_key(), which warns and
does not register if the provided memory is a static object.
blk-crypto-fallback currently has a static blk_crypto_profile and calls
blk_crypto_profile_init() thereupon, resulting in the warning and
failure to register.

Fortunately it is simple enough to use a dynamically allocated profile
and make lockdep function correctly.

Fixes: 2fb48d88e77f ("blk-crypto: use dynamic lock class for blk_crypto_profile::lock")
Cc: stable@vger.kernel.org
Signed-off-by: Sweet Tea Dorminy &lt;sweettea-kernel@dorminy.me&gt;
Reviewed-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20230817141615.15387-1-sweettea-kernel@dorminy.me
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c984ff1423ae9f70b1f28ce811856db0d9c99021 upstream.

blk_crypto_profile_init() calls lockdep_register_key(), which warns and
does not register if the provided memory is a static object.
blk-crypto-fallback currently has a static blk_crypto_profile and calls
blk_crypto_profile_init() thereupon, resulting in the warning and
failure to register.

Fortunately it is simple enough to use a dynamically allocated profile
and make lockdep function correctly.

Fixes: 2fb48d88e77f ("blk-crypto: use dynamic lock class for blk_crypto_profile::lock")
Cc: stable@vger.kernel.org
Signed-off-by: Sweet Tea Dorminy &lt;sweettea-kernel@dorminy.me&gt;
Reviewed-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20230817141615.15387-1-sweettea-kernel@dorminy.me
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-mq: Fix stall due to recursive flush plug</title>
<updated>2023-08-03T08:23:48+00:00</updated>
<author>
<name>Ross Lagerwall</name>
<email>ross.lagerwall@citrix.com</email>
</author>
<published>2023-07-14T10:11:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=557ea2ff05193c2a04cf05233102a774d9e57e52'/>
<id>557ea2ff05193c2a04cf05233102a774d9e57e52</id>
<content type='text'>
[ Upstream commit 70904263512a74a3b8941dd9e6e515ca6fc57821 ]

We have seen rare IO stalls as follows:

* blk_mq_plug_issue_direct() is entered with an mq_list containing two
requests.
* For the first request, it sets last == false and enters the driver's
queue_rq callback.
* The driver queue_rq callback indirectly calls schedule() which calls
blk_flush_plug(). This may happen if the driver has the
BLK_MQ_F_BLOCKING flag set and is allowed to sleep in -&gt;queue_rq.
* blk_flush_plug() handles the remaining request in the mq_list. mq_list
is now empty.
* The original call to queue_rq resumes (with last == false).
* The loop in blk_mq_plug_issue_direct() terminates because there are no
remaining requests in mq_list.

The IO is now stalled because the last request submitted to the driver
had last == false and there was no subsequent call to commit_rqs().

Fix this by returning early in blk_mq_flush_plug_list() if rq_count is 0
which it will be in the recursive case, rather than checking if the
mq_list is empty. At the same time, adjust one of the callers to skip
the mq_list empty check as it is not necessary.

Fixes: dc5fc361d891 ("block: attempt direct issue of plug list")
Signed-off-by: Ross Lagerwall &lt;ross.lagerwall@citrix.com&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20230714101106.3635611-1-ross.lagerwall@citrix.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 70904263512a74a3b8941dd9e6e515ca6fc57821 ]

We have seen rare IO stalls as follows:

* blk_mq_plug_issue_direct() is entered with an mq_list containing two
requests.
* For the first request, it sets last == false and enters the driver's
queue_rq callback.
* The driver queue_rq callback indirectly calls schedule() which calls
blk_flush_plug(). This may happen if the driver has the
BLK_MQ_F_BLOCKING flag set and is allowed to sleep in -&gt;queue_rq.
* blk_flush_plug() handles the remaining request in the mq_list. mq_list
is now empty.
* The original call to queue_rq resumes (with last == false).
* The loop in blk_mq_plug_issue_direct() terminates because there are no
remaining requests in mq_list.

The IO is now stalled because the last request submitted to the driver
had last == false and there was no subsequent call to commit_rqs().

Fix this by returning early in blk_mq_flush_plug_list() if rq_count is 0
which it will be in the recursive case, rather than checking if the
mq_list is empty. At the same time, adjust one of the callers to skip
the mq_list empty check as it is not necessary.

Fixes: dc5fc361d891 ("block: attempt direct issue of plug list")
Signed-off-by: Ross Lagerwall &lt;ross.lagerwall@citrix.com&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20230714101106.3635611-1-ross.lagerwall@citrix.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>blk-crypto: use dynamic lock class for blk_crypto_profile::lock</title>
<updated>2023-07-23T11:49:21+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2023-06-10T06:11:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=49f6ac6f1cde88bab4e530317510d1cf8870e404'/>
<id>49f6ac6f1cde88bab4e530317510d1cf8870e404</id>
<content type='text'>
[ Upstream commit 2fb48d88e77f29bf9d278f25bcfe82cf59a0e09b ]

When a device-mapper device is passing through the inline encryption
support of an underlying device, calls to blk_crypto_evict_key() take
the blk_crypto_profile::lock of the device-mapper device, then take the
blk_crypto_profile::lock of the underlying device (nested).  This isn't
a real deadlock, but it causes a lockdep report because there is only
one lock class for all instances of this lock.

Lockdep subclasses don't really work here because the hierarchy of block
devices is dynamic and could have more than 2 levels.

Instead, register a dynamic lock class for each blk_crypto_profile, and
associate that with the lock.

This avoids false-positive lockdep reports like the following:

    ============================================
    WARNING: possible recursive locking detected
    6.4.0-rc5 #2 Not tainted
    --------------------------------------------
    fscryptctl/1421 is trying to acquire lock:
    ffffff80829ca418 (&amp;profile-&gt;lock){++++}-{3:3}, at: __blk_crypto_evict_key+0x44/0x1c0

                   but task is already holding lock:
    ffffff8086b68ca8 (&amp;profile-&gt;lock){++++}-{3:3}, at: __blk_crypto_evict_key+0xc8/0x1c0

                   other info that might help us debug this:
     Possible unsafe locking scenario:

           CPU0
           ----
      lock(&amp;profile-&gt;lock);
      lock(&amp;profile-&gt;lock);

                    *** DEADLOCK ***

     May be due to missing lock nesting notation

Fixes: 1b2628397058 ("block: Keyslot Manager for Inline Encryption")
Reported-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20230610061139.212085-1-ebiggers@kernel.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 2fb48d88e77f29bf9d278f25bcfe82cf59a0e09b ]

When a device-mapper device is passing through the inline encryption
support of an underlying device, calls to blk_crypto_evict_key() take
the blk_crypto_profile::lock of the device-mapper device, then take the
blk_crypto_profile::lock of the underlying device (nested).  This isn't
a real deadlock, but it causes a lockdep report because there is only
one lock class for all instances of this lock.

Lockdep subclasses don't really work here because the hierarchy of block
devices is dynamic and could have more than 2 levels.

Instead, register a dynamic lock class for each blk_crypto_profile, and
associate that with the lock.

This avoids false-positive lockdep reports like the following:

    ============================================
    WARNING: possible recursive locking detected
    6.4.0-rc5 #2 Not tainted
    --------------------------------------------
    fscryptctl/1421 is trying to acquire lock:
    ffffff80829ca418 (&amp;profile-&gt;lock){++++}-{3:3}, at: __blk_crypto_evict_key+0x44/0x1c0

                   but task is already holding lock:
    ffffff8086b68ca8 (&amp;profile-&gt;lock){++++}-{3:3}, at: __blk_crypto_evict_key+0xc8/0x1c0

                   other info that might help us debug this:
     Possible unsafe locking scenario:

           CPU0
           ----
      lock(&amp;profile-&gt;lock);
      lock(&amp;profile-&gt;lock);

                    *** DEADLOCK ***

     May be due to missing lock nesting notation

Fixes: 1b2628397058 ("block: Keyslot Manager for Inline Encryption")
Reported-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20230610061139.212085-1-ebiggers@kernel.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
