<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/block, branch v6.2.8</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>block: count 'ios' and 'sectors' when io is done for bio-based device</title>
<updated>2023-03-22T12:37:50+00:00</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2023-02-23T09:12:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b477180587d81a4dd756361098bd534dfa6bb53d'/>
<id>b477180587d81a4dd756361098bd534dfa6bb53d</id>
<content type='text'>
[ Upstream commit 5f27571382ca42daa3e3d40d1b252bf18c2b61d2 ]

While using iostat for raid, I observed very strange 'await'
occasionally, and turns out it's due to that 'ios' and 'sectors' is
counted in bdev_start_io_acct(), while 'nsecs' is counted in
bdev_end_io_acct(). I'm not sure why they are ccounted like that
but I think this behaviour is obviously wrong because user will get
wrong disk stats.

Fix the problem by counting 'ios' and 'sectors' when io is done, like
what rq-based device does.

Fixes: 394ffa503bc4 ("blk: introduce generic io stat accounting help function")
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230223091226.1135678-1-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 5f27571382ca42daa3e3d40d1b252bf18c2b61d2 ]

While using iostat for raid, I observed very strange 'await'
occasionally, and turns out it's due to that 'ios' and 'sectors' is
counted in bdev_start_io_acct(), while 'nsecs' is counted in
bdev_end_io_acct(). I'm not sure why they are ccounted like that
but I think this behaviour is obviously wrong because user will get
wrong disk stats.

Fix the problem by counting 'ios' and 'sectors' when io is done, like
what rq-based device does.

Fixes: 394ffa503bc4 ("blk: introduce generic io stat accounting help function")
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20230223091226.1135678-1-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>block: sunvdc: add check for mdesc_grab() returning NULL</title>
<updated>2023-03-22T12:37:50+00:00</updated>
<author>
<name>Liang He</name>
<email>windhl@126.com</email>
</author>
<published>2023-03-15T06:20:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a6633022d7d6c21436f55d6323f2a1e856238d44'/>
<id>a6633022d7d6c21436f55d6323f2a1e856238d44</id>
<content type='text'>
[ Upstream commit 6030363199e3a6341afb467ddddbed56640cbf6a ]

In vdc_port_probe(), we should check the return value of mdesc_grab() as
it may return NULL, which can cause potential NPD bug.

Fixes: 43fdf27470b2 ("[SPARC64]: Abstract out mdesc accesses for better MD update handling.")
Signed-off-by: Liang He &lt;windhl@126.com&gt;
Link: https://lore.kernel.org/r/20230315062032.1741692-1-windhl@126.com
[axboe: style cleanup]
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 6030363199e3a6341afb467ddddbed56640cbf6a ]

In vdc_port_probe(), we should check the return value of mdesc_grab() as
it may return NULL, which can cause potential NPD bug.

Fixes: 43fdf27470b2 ("[SPARC64]: Abstract out mdesc accesses for better MD update handling.")
Signed-off-by: Liang He &lt;windhl@126.com&gt;
Link: https://lore.kernel.org/r/20230315062032.1741692-1-windhl@126.com
[axboe: style cleanup]
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: null_blk: Fix handling of fake timeout request</title>
<updated>2023-03-22T12:37:50+00:00</updated>
<author>
<name>Damien Le Moal</name>
<email>damien.lemoal@opensource.wdc.com</email>
</author>
<published>2023-03-14T04:11:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=06aca9bee911ef4fa425ce909e034b9bc2cd72f8'/>
<id>06aca9bee911ef4fa425ce909e034b9bc2cd72f8</id>
<content type='text'>
[ Upstream commit 63f886597085f346276e3b3c8974de0100d65f32 ]

When injecting a fake timeout into the null_blk driver using
fail_io_timeout, the request timeout handler does not execute
blk_mq_complete_request(), so the complete callback is never executed
for a timedout request.

The null_blk driver also has a driver-specific fake timeout mechanism
which does not have this problem. Fix the problem with fail_io_timeout
by using the same meachanism as null_blk internal timeout feature, using
the fake_timeout field of null_blk commands.

Reported-by: Akinobu Mita &lt;akinobu.mita@gmail.com&gt;
Fixes: de3510e52b0a ("null_blk: fix command timeout completion handling")
Signed-off-by: Damien Le Moal &lt;damien.lemoal@opensource.wdc.com&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20230314041106.19173-2-damien.lemoal@opensource.wdc.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 63f886597085f346276e3b3c8974de0100d65f32 ]

When injecting a fake timeout into the null_blk driver using
fail_io_timeout, the request timeout handler does not execute
blk_mq_complete_request(), so the complete callback is never executed
for a timedout request.

The null_blk driver also has a driver-specific fake timeout mechanism
which does not have this problem. Fix the problem with fail_io_timeout
by using the same meachanism as null_blk internal timeout feature, using
the fake_timeout field of null_blk commands.

Reported-by: Akinobu Mita &lt;akinobu.mita@gmail.com&gt;
Fixes: de3510e52b0a ("null_blk: fix command timeout completion handling")
Signed-off-by: Damien Le Moal &lt;damien.lemoal@opensource.wdc.com&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20230314041106.19173-2-damien.lemoal@opensource.wdc.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>loop: Fix use-after-free issues</title>
<updated>2023-03-22T12:37:48+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bvanassche@acm.org</email>
</author>
<published>2023-03-14T18:21:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6917395c4667cfb607ed8bf1826205a59414657c'/>
<id>6917395c4667cfb607ed8bf1826205a59414657c</id>
<content type='text'>
[ Upstream commit 9b0cb770f5d7b1ff40bea7ca385438ee94570eec ]

do_req_filebacked() calls blk_mq_complete_request() synchronously or
asynchronously when using asynchronous I/O unless memory allocation fails.
Hence, modify loop_handle_cmd() such that it does not dereference 'cmd' nor
'rq' after do_req_filebacked() finished unless we are sure that the request
has not yet been completed. This patch fixes the following kernel crash:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000054
Call trace:
 css_put.42938+0x1c/0x1ac
 loop_process_work+0xc8c/0xfd4
 loop_rootcg_workfn+0x24/0x34
 process_one_work+0x244/0x558
 worker_thread+0x400/0x8fc
 kthread+0x16c/0x1e0
 ret_from_fork+0x10/0x20

Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Ming Lei &lt;ming.lei@redhat.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Dan Schatzberg &lt;schatzberg.dan@gmail.com&gt;
Fixes: c74d40e8b5e2 ("loop: charge i/o to mem and blk cg")
Fixes: bc07c10a3603 ("block: loop: support DIO &amp; AIO")
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20230314182155.80625-1-bvanassche@acm.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 9b0cb770f5d7b1ff40bea7ca385438ee94570eec ]

do_req_filebacked() calls blk_mq_complete_request() synchronously or
asynchronously when using asynchronous I/O unless memory allocation fails.
Hence, modify loop_handle_cmd() such that it does not dereference 'cmd' nor
'rq' after do_req_filebacked() finished unless we are sure that the request
has not yet been completed. This patch fixes the following kernel crash:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000054
Call trace:
 css_put.42938+0x1c/0x1ac
 loop_process_work+0xc8c/0xfd4
 loop_rootcg_workfn+0x24/0x34
 process_one_work+0x244/0x558
 worker_thread+0x400/0x8fc
 kthread+0x16c/0x1e0
 ret_from_fork+0x10/0x20

Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Ming Lei &lt;ming.lei@redhat.com&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Dan Schatzberg &lt;schatzberg.dan@gmail.com&gt;
Fixes: c74d40e8b5e2 ("loop: charge i/o to mem and blk cg")
Fixes: bc07c10a3603 ("block: loop: support DIO &amp; AIO")
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20230314182155.80625-1-bvanassche@acm.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>
<entry>
<title>loop: loop_set_status_from_info() check before assignment</title>
<updated>2023-03-11T12:50:35+00:00</updated>
<author>
<name>Zhong Jinghua</name>
<email>zhongjinghua@huawei.com</email>
</author>
<published>2023-02-21T09:50:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=258809bf22bf71d53247856f374f2b1d055f2fd4'/>
<id>258809bf22bf71d53247856f374f2b1d055f2fd4</id>
<content type='text'>
[ Upstream commit 9f6ad5d533d1c71e51bdd06a5712c4fbc8768dfa ]

In loop_set_status_from_info(), lo-&gt;lo_offset and lo-&gt;lo_sizelimit should
be checked before reassignment, because if an overflow error occurs, the
original correct value will be changed to the wrong value, and it will not
be changed back.

More, the original patch did not solve the problem, the value was set and
ioctl returned an error, but the subsequent io used the value in the loop
driver, which still caused an alarm:

loop_handle_cmd
 do_req_filebacked
  loff_t pos = ((loff_t) blk_rq_pos(rq) &lt;&lt; 9) + lo-&gt;lo_offset;
  lo_rw_aio
   cmd-&gt;iocb.ki_pos = pos

Fixes: c490a0b5a4f3 ("loop: Check for overflow while configuring loop")
Signed-off-by: Zhong Jinghua &lt;zhongjinghua@huawei.com&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Link: https://lore.kernel.org/r/20230221095027.3656193-1-zhongjinghua@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 9f6ad5d533d1c71e51bdd06a5712c4fbc8768dfa ]

In loop_set_status_from_info(), lo-&gt;lo_offset and lo-&gt;lo_sizelimit should
be checked before reassignment, because if an overflow error occurs, the
original correct value will be changed to the wrong value, and it will not
be changed back.

More, the original patch did not solve the problem, the value was set and
ioctl returned an error, but the subsequent io used the value in the loop
driver, which still caused an alarm:

loop_handle_cmd
 do_req_filebacked
  loff_t pos = ((loff_t) blk_rq_pos(rq) &lt;&lt; 9) + lo-&gt;lo_offset;
  lo_rw_aio
   cmd-&gt;iocb.ki_pos = pos

Fixes: c490a0b5a4f3 ("loop: Check for overflow while configuring loop")
Signed-off-by: Zhong Jinghua &lt;zhongjinghua@huawei.com&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Link: https://lore.kernel.org/r/20230221095027.3656193-1-zhongjinghua@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>brd: use radix_tree_maybe_preload instead of radix_tree_preload</title>
<updated>2023-03-10T08:29:57+00:00</updated>
<author>
<name>Pankaj Raghav</name>
<email>p.raghav@samsung.com</email>
</author>
<published>2023-02-17T12:14:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2cbe0f05664de37bbc084b79001f1436e19b5da6'/>
<id>2cbe0f05664de37bbc084b79001f1436e19b5da6</id>
<content type='text'>
commit 0aa2988e4fd23c0c8b33999d7b47dfbc5e6bf24b upstream.

Unconditionally calling radix_tree_preload_end() results in a OOPS
message as the preload is only conditionally called for
gfpflags_allow_blocking().

[   20.267323] BUG: using smp_processor_id() in preemptible [00000000] code: fio/416
[   20.267837] caller is brd_insert_page.part.0+0xbe/0x190 [brd]
[   20.269436] Call Trace:
[   20.269598]  &lt;TASK&gt;
[   20.269742]  dump_stack_lvl+0x32/0x50
[   20.269982]  check_preemption_disabled+0xd1/0xe0
[   20.270289]  brd_insert_page.part.0+0xbe/0x190 [brd]
[   20.270664]  brd_submit_bio+0x33f/0xf40 [brd]

Use radix_tree_maybe_preload() which does preload only if
gfpflags_allow_blocking() is true but also takes the lock. Therefore,
unconditionally calling radix_tree_preload_end() should not create any
issues and the message disappears.

Fixes: 6ded703c56c2 ("brd: check for REQ_NOWAIT and set correct page allocation mask")
Signed-off-by: Pankaj Raghav &lt;p.raghav@samsung.com&gt;
Link: https://lore.kernel.org/r/20230217121442.33914-1-p.raghav@samsung.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 0aa2988e4fd23c0c8b33999d7b47dfbc5e6bf24b upstream.

Unconditionally calling radix_tree_preload_end() results in a OOPS
message as the preload is only conditionally called for
gfpflags_allow_blocking().

[   20.267323] BUG: using smp_processor_id() in preemptible [00000000] code: fio/416
[   20.267837] caller is brd_insert_page.part.0+0xbe/0x190 [brd]
[   20.269436] Call Trace:
[   20.269598]  &lt;TASK&gt;
[   20.269742]  dump_stack_lvl+0x32/0x50
[   20.269982]  check_preemption_disabled+0xd1/0xe0
[   20.270289]  brd_insert_page.part.0+0xbe/0x190 [brd]
[   20.270664]  brd_submit_bio+0x33f/0xf40 [brd]

Use radix_tree_maybe_preload() which does preload only if
gfpflags_allow_blocking() is true but also takes the lock. Therefore,
unconditionally calling radix_tree_preload_end() should not create any
issues and the message disappears.

Fixes: 6ded703c56c2 ("brd: check for REQ_NOWAIT and set correct page allocation mask")
Signed-off-by: Pankaj Raghav &lt;p.raghav@samsung.com&gt;
Link: https://lore.kernel.org/r/20230217121442.33914-1-p.raghav@samsung.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>rbd: avoid use-after-free in do_rbd_add() when rbd_dev_create() fails</title>
<updated>2023-03-10T08:29:47+00:00</updated>
<author>
<name>Ilya Dryomov</name>
<email>idryomov@gmail.com</email>
</author>
<published>2023-02-24T17:48:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cc8c0dd2984503ed09efa37bcafcef3d3da104e8'/>
<id>cc8c0dd2984503ed09efa37bcafcef3d3da104e8</id>
<content type='text'>
commit f7c4d9b133c7a04ca619355574e96b6abf209fba upstream.

If getting an ID or setting up a work queue in rbd_dev_create() fails,
use-after-free on rbd_dev-&gt;rbd_client, rbd_dev-&gt;spec and rbd_dev-&gt;opts
is triggered in do_rbd_add().  The root cause is that the ownership of
these structures is transfered to rbd_dev prematurely and they all end
up getting freed when rbd_dev_create() calls rbd_dev_free() prior to
returning to do_rbd_add().

Found by Linux Verification Center (linuxtesting.org) with SVACE, an
incomplete patch submitted by Natalia Petrova &lt;n.petrova@fintech.ru&gt;.

Cc: stable@vger.kernel.org
Fixes: 1643dfa4c2c8 ("rbd: introduce a per-device ordered workqueue")
Signed-off-by: Ilya Dryomov &lt;idryomov@gmail.com&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 f7c4d9b133c7a04ca619355574e96b6abf209fba upstream.

If getting an ID or setting up a work queue in rbd_dev_create() fails,
use-after-free on rbd_dev-&gt;rbd_client, rbd_dev-&gt;spec and rbd_dev-&gt;opts
is triggered in do_rbd_add().  The root cause is that the ownership of
these structures is transfered to rbd_dev prematurely and they all end
up getting freed when rbd_dev_create() calls rbd_dev_free() prior to
returning to do_rbd_add().

Found by Linux Verification Center (linuxtesting.org) with SVACE, an
incomplete patch submitted by Natalia Petrova &lt;n.petrova@fintech.ru&gt;.

Cc: stable@vger.kernel.org
Fixes: 1643dfa4c2c8 ("rbd: introduce a per-device ordered workqueue")
Signed-off-by: Ilya Dryomov &lt;idryomov@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>brd: check for REQ_NOWAIT and set correct page allocation mask</title>
<updated>2023-03-10T08:29:36+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>axboe@kernel.dk</email>
</author>
<published>2023-02-16T15:01:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=57a0078b1a07dff4397744d911fc89f1d23b117e'/>
<id>57a0078b1a07dff4397744d911fc89f1d23b117e</id>
<content type='text'>
commit 6ded703c56c21bfb259725d4f1831a5feb563e9b upstream.

If REQ_NOWAIT is set, then do a non-blocking allocation if the operation
is a write and we need to insert a new page. Currently REQ_NOWAIT cannot
be set as the queue isn't marked as supporting nowait, this change is in
preparation for allowing that.

radix_tree_preload() warns on attempting to call it with an allocation
mask that doesn't allow blocking. While that warning could arguably
be removed, we need to handle radix insertion failures anyway as they
are more likely if we cannot block to get memory.

Remove legacy BUG_ON()'s and turn them into proper errors instead, one
for the allocation failure and one for finding a page that doesn't
match the correct index.

Cc: stable@vger.kernel.org # 5.10+
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
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 6ded703c56c21bfb259725d4f1831a5feb563e9b upstream.

If REQ_NOWAIT is set, then do a non-blocking allocation if the operation
is a write and we need to insert a new page. Currently REQ_NOWAIT cannot
be set as the queue isn't marked as supporting nowait, this change is in
preparation for allowing that.

radix_tree_preload() warns on attempting to call it with an allocation
mask that doesn't allow blocking. While that warning could arguably
be removed, we need to handle radix insertion failures anyway as they
are more likely if we cannot block to get memory.

Remove legacy BUG_ON()'s and turn them into proper errors instead, one
for the allocation failure and one for finding a page that doesn't
match the correct index.

Cc: stable@vger.kernel.org # 5.10+
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
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>brd: return 0/-error from brd_insert_page()</title>
<updated>2023-03-10T08:29:36+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>axboe@kernel.dk</email>
</author>
<published>2023-02-16T14:57:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=87f1bf26501a51aeabc7aeb55b92afc550260d61'/>
<id>87f1bf26501a51aeabc7aeb55b92afc550260d61</id>
<content type='text'>
commit db0ccc44a20b4bb3039c0f6885a1f9c3323c7673 upstream.

It currently returns a page, but callers just check for NULL/page to
gauge success. Clean this up and return the appropriate error directly
instead.

Cc: stable@vger.kernel.org # 5.10+
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
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 db0ccc44a20b4bb3039c0f6885a1f9c3323c7673 upstream.

It currently returns a page, but callers just check for NULL/page to
gauge success. Clean this up and return the appropriate error directly
instead.

Cc: stable@vger.kernel.org # 5.10+
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
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>brd: mark as nowait compatible</title>
<updated>2023-03-10T08:29:36+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>axboe@kernel.dk</email>
</author>
<published>2023-02-15T23:43:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c3435c7e7e06d8dea390c63149d5f0447f640127'/>
<id>c3435c7e7e06d8dea390c63149d5f0447f640127</id>
<content type='text'>
commit 67205f80be9910207481406c47f7d85e703fb2e9 upstream.

By default, non-mq drivers do not support nowait. This causes io_uring
to use a slower path as the driver cannot be trust not to block. brd
can safely set the nowait flag, as worst case all it does is a NOIO
allocation.

For io_uring, this makes a substantial difference. Before:

submitter=0, tid=453, file=/dev/ram0, node=-1
polled=0, fixedbufs=1/0, register_files=1, buffered=0, QD=128
Engine=io_uring, sq_ring=128, cq_ring=128
IOPS=440.03K, BW=1718MiB/s, IOS/call=32/31
IOPS=428.96K, BW=1675MiB/s, IOS/call=32/32
IOPS=442.59K, BW=1728MiB/s, IOS/call=32/31
IOPS=419.65K, BW=1639MiB/s, IOS/call=32/32
IOPS=426.82K, BW=1667MiB/s, IOS/call=32/31

and after:

submitter=0, tid=354, file=/dev/ram0, node=-1
polled=0, fixedbufs=1/0, register_files=1, buffered=0, QD=128
Engine=io_uring, sq_ring=128, cq_ring=128
IOPS=3.37M, BW=13.15GiB/s, IOS/call=32/31
IOPS=3.45M, BW=13.46GiB/s, IOS/call=32/31
IOPS=3.43M, BW=13.42GiB/s, IOS/call=32/32
IOPS=3.43M, BW=13.39GiB/s, IOS/call=32/31
IOPS=3.43M, BW=13.38GiB/s, IOS/call=32/31

or about an 8x in difference. Now that brd is prepared to deal with
REQ_NOWAIT reads/writes, mark it as supporting that.

Cc: stable@vger.kernel.org # 5.10+
Link: https://lore.kernel.org/linux-block/20230203103005.31290-1-p.raghav@samsung.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 67205f80be9910207481406c47f7d85e703fb2e9 upstream.

By default, non-mq drivers do not support nowait. This causes io_uring
to use a slower path as the driver cannot be trust not to block. brd
can safely set the nowait flag, as worst case all it does is a NOIO
allocation.

For io_uring, this makes a substantial difference. Before:

submitter=0, tid=453, file=/dev/ram0, node=-1
polled=0, fixedbufs=1/0, register_files=1, buffered=0, QD=128
Engine=io_uring, sq_ring=128, cq_ring=128
IOPS=440.03K, BW=1718MiB/s, IOS/call=32/31
IOPS=428.96K, BW=1675MiB/s, IOS/call=32/32
IOPS=442.59K, BW=1728MiB/s, IOS/call=32/31
IOPS=419.65K, BW=1639MiB/s, IOS/call=32/32
IOPS=426.82K, BW=1667MiB/s, IOS/call=32/31

and after:

submitter=0, tid=354, file=/dev/ram0, node=-1
polled=0, fixedbufs=1/0, register_files=1, buffered=0, QD=128
Engine=io_uring, sq_ring=128, cq_ring=128
IOPS=3.37M, BW=13.15GiB/s, IOS/call=32/31
IOPS=3.45M, BW=13.46GiB/s, IOS/call=32/31
IOPS=3.43M, BW=13.42GiB/s, IOS/call=32/32
IOPS=3.43M, BW=13.39GiB/s, IOS/call=32/31
IOPS=3.43M, BW=13.38GiB/s, IOS/call=32/31

or about an 8x in difference. Now that brd is prepared to deal with
REQ_NOWAIT reads/writes, mark it as supporting that.

Cc: stable@vger.kernel.org # 5.10+
Link: https://lore.kernel.org/linux-block/20230203103005.31290-1-p.raghav@samsung.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>
</feed>
