<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/block, branch linux-5.11.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>blk-mq: Swap two calls in blk_mq_exit_queue()</title>
<updated>2021-05-19T08:29:53+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bvanassche@acm.org</email>
</author>
<published>2021-05-13T17:15:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=929778cfc8f31f3fa793a5fa5f10fe3cd30f63ff'/>
<id>929778cfc8f31f3fa793a5fa5f10fe3cd30f63ff</id>
<content type='text'>
[ Upstream commit 630ef623ed26c18a457cdc070cf24014e50129c2 ]

If a tag set is shared across request queues (e.g. SCSI LUNs) then the
block layer core keeps track of the number of active request queues in
tags-&gt;active_queues. blk_mq_tag_busy() and blk_mq_tag_idle() update that
atomic counter if the hctx flag BLK_MQ_F_TAG_QUEUE_SHARED is set. Make
sure that blk_mq_exit_queue() calls blk_mq_tag_idle() before that flag is
cleared by blk_mq_del_queue_tag_set().

Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Ming Lei &lt;ming.lei@redhat.com&gt;
Cc: Hannes Reinecke &lt;hare@suse.com&gt;
Fixes: 0d2602ca30e4 ("blk-mq: improve support for shared tags maps")
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/20210513171529.7977-1-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 630ef623ed26c18a457cdc070cf24014e50129c2 ]

If a tag set is shared across request queues (e.g. SCSI LUNs) then the
block layer core keeps track of the number of active request queues in
tags-&gt;active_queues. blk_mq_tag_busy() and blk_mq_tag_idle() update that
atomic counter if the hctx flag BLK_MQ_F_TAG_QUEUE_SHARED is set. Make
sure that blk_mq_exit_queue() calls blk_mq_tag_idle() before that flag is
cleared by blk_mq_del_queue_tag_set().

Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Ming Lei &lt;ming.lei@redhat.com&gt;
Cc: Hannes Reinecke &lt;hare@suse.com&gt;
Fixes: 0d2602ca30e4 ("blk-mq: improve support for shared tags maps")
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/20210513171529.7977-1-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>blk-mq: plug request for shared sbitmap</title>
<updated>2021-05-19T08:29:53+00:00</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2021-05-14T02:20:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=273047c938ac3cd33ec8c037f5e7a1a7f63b9566'/>
<id>273047c938ac3cd33ec8c037f5e7a1a7f63b9566</id>
<content type='text'>
[ Upstream commit 03f26d8f11403295de445b6e4e0e57ac57755791 ]

In case of shared sbitmap, request won't be held in plug list any more
sine commit 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per
tagset"), this way makes request merge from flush plug list &amp; batching
submission not possible, so cause performance regression.

Yanhui reports performance regression when running sequential IO
test(libaio, 16 jobs, 8 depth for each job) in VM, and the VM disk
is emulated with image stored on xfs/megaraid_sas.

Fix the issue by recovering original behavior to allow to hold request
in plug list.

Cc: Yanhui Ma &lt;yama@redhat.com&gt;
Cc: John Garry &lt;john.garry@huawei.com&gt;
Cc: Bart Van Assche &lt;bvanassche@acm.org&gt;
Cc: kashyap.desai@broadcom.com
Fixes: 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per tagset")
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20210514022052.1047665-1-ming.lei@redhat.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 03f26d8f11403295de445b6e4e0e57ac57755791 ]

In case of shared sbitmap, request won't be held in plug list any more
sine commit 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per
tagset"), this way makes request merge from flush plug list &amp; batching
submission not possible, so cause performance regression.

Yanhui reports performance regression when running sequential IO
test(libaio, 16 jobs, 8 depth for each job) in VM, and the VM disk
is emulated with image stored on xfs/megaraid_sas.

Fix the issue by recovering original behavior to allow to hold request
in plug list.

Cc: Yanhui Ma &lt;yama@redhat.com&gt;
Cc: John Garry &lt;john.garry@huawei.com&gt;
Cc: Bart Van Assche &lt;bvanassche@acm.org&gt;
Cc: kashyap.desai@broadcom.com
Fixes: 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per tagset")
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20210514022052.1047665-1-ming.lei@redhat.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>kyber: fix out of bounds access when preempted</title>
<updated>2021-05-19T08:29:52+00:00</updated>
<author>
<name>Omar Sandoval</name>
<email>osandov@fb.com</email>
</author>
<published>2021-05-11T00:05:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a287cd84e047045f5a4d4da793414e848de627c6'/>
<id>a287cd84e047045f5a4d4da793414e848de627c6</id>
<content type='text'>
[ Upstream commit efed9a3337e341bd0989161b97453b52567bc59d ]

__blk_mq_sched_bio_merge() gets the ctx and hctx for the current CPU and
passes the hctx to -&gt;bio_merge(). kyber_bio_merge() then gets the ctx
for the current CPU again and uses that to get the corresponding Kyber
context in the passed hctx. However, the thread may be preempted between
the two calls to blk_mq_get_ctx(), and the ctx returned the second time
may no longer correspond to the passed hctx. This "works" accidentally
most of the time, but it can cause us to read garbage if the second ctx
came from an hctx with more ctx's than the first one (i.e., if
ctx-&gt;index_hw[hctx-&gt;type] &gt; hctx-&gt;nr_ctx).

This manifested as this UBSAN array index out of bounds error reported
by Jakub:

UBSAN: array-index-out-of-bounds in ../kernel/locking/qspinlock.c:130:9
index 13106 is out of range for type 'long unsigned int [128]'
Call Trace:
 dump_stack+0xa4/0xe5
 ubsan_epilogue+0x5/0x40
 __ubsan_handle_out_of_bounds.cold.13+0x2a/0x34
 queued_spin_lock_slowpath+0x476/0x480
 do_raw_spin_lock+0x1c2/0x1d0
 kyber_bio_merge+0x112/0x180
 blk_mq_submit_bio+0x1f5/0x1100
 submit_bio_noacct+0x7b0/0x870
 submit_bio+0xc2/0x3a0
 btrfs_map_bio+0x4f0/0x9d0
 btrfs_submit_data_bio+0x24e/0x310
 submit_one_bio+0x7f/0xb0
 submit_extent_page+0xc4/0x440
 __extent_writepage_io+0x2b8/0x5e0
 __extent_writepage+0x28d/0x6e0
 extent_write_cache_pages+0x4d7/0x7a0
 extent_writepages+0xa2/0x110
 do_writepages+0x8f/0x180
 __writeback_single_inode+0x99/0x7f0
 writeback_sb_inodes+0x34e/0x790
 __writeback_inodes_wb+0x9e/0x120
 wb_writeback+0x4d2/0x660
 wb_workfn+0x64d/0xa10
 process_one_work+0x53a/0xa80
 worker_thread+0x69/0x5b0
 kthread+0x20b/0x240
 ret_from_fork+0x1f/0x30

Only Kyber uses the hctx, so fix it by passing the request_queue to
-&gt;bio_merge() instead. BFQ and mq-deadline just use that, and Kyber can
map the queues itself to avoid the mismatch.

Fixes: a6088845c2bf ("block: kyber: make kyber more friendly with merging")
Reported-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Omar Sandoval &lt;osandov@fb.com&gt;
Link: https://lore.kernel.org/r/c7598605401a48d5cfeadebb678abd10af22b83f.1620691329.git.osandov@fb.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 efed9a3337e341bd0989161b97453b52567bc59d ]

__blk_mq_sched_bio_merge() gets the ctx and hctx for the current CPU and
passes the hctx to -&gt;bio_merge(). kyber_bio_merge() then gets the ctx
for the current CPU again and uses that to get the corresponding Kyber
context in the passed hctx. However, the thread may be preempted between
the two calls to blk_mq_get_ctx(), and the ctx returned the second time
may no longer correspond to the passed hctx. This "works" accidentally
most of the time, but it can cause us to read garbage if the second ctx
came from an hctx with more ctx's than the first one (i.e., if
ctx-&gt;index_hw[hctx-&gt;type] &gt; hctx-&gt;nr_ctx).

This manifested as this UBSAN array index out of bounds error reported
by Jakub:

UBSAN: array-index-out-of-bounds in ../kernel/locking/qspinlock.c:130:9
index 13106 is out of range for type 'long unsigned int [128]'
Call Trace:
 dump_stack+0xa4/0xe5
 ubsan_epilogue+0x5/0x40
 __ubsan_handle_out_of_bounds.cold.13+0x2a/0x34
 queued_spin_lock_slowpath+0x476/0x480
 do_raw_spin_lock+0x1c2/0x1d0
 kyber_bio_merge+0x112/0x180
 blk_mq_submit_bio+0x1f5/0x1100
 submit_bio_noacct+0x7b0/0x870
 submit_bio+0xc2/0x3a0
 btrfs_map_bio+0x4f0/0x9d0
 btrfs_submit_data_bio+0x24e/0x310
 submit_one_bio+0x7f/0xb0
 submit_extent_page+0xc4/0x440
 __extent_writepage_io+0x2b8/0x5e0
 __extent_writepage+0x28d/0x6e0
 extent_write_cache_pages+0x4d7/0x7a0
 extent_writepages+0xa2/0x110
 do_writepages+0x8f/0x180
 __writeback_single_inode+0x99/0x7f0
 writeback_sb_inodes+0x34e/0x790
 __writeback_inodes_wb+0x9e/0x120
 wb_writeback+0x4d2/0x660
 wb_workfn+0x64d/0xa10
 process_one_work+0x53a/0xa80
 worker_thread+0x69/0x5b0
 kthread+0x20b/0x240
 ret_from_fork+0x1f/0x30

Only Kyber uses the hctx, so fix it by passing the request_queue to
-&gt;bio_merge() instead. BFQ and mq-deadline just use that, and Kyber can
map the queues itself to avoid the mismatch.

Fixes: a6088845c2bf ("block: kyber: make kyber more friendly with merging")
Reported-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Omar Sandoval &lt;osandov@fb.com&gt;
Link: https://lore.kernel.org/r/c7598605401a48d5cfeadebb678abd10af22b83f.1620691329.git.osandov@fb.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-iocost: fix weight updates of inner active iocgs</title>
<updated>2021-05-19T08:29:49+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2021-05-12T01:38:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0df9ad4878d6016ad686ae064ad73bc26fca66df'/>
<id>0df9ad4878d6016ad686ae064ad73bc26fca66df</id>
<content type='text'>
commit e9f4eee9a0023ba22db9560d4cc6ee63f933dae8 upstream.

When the weight of an active iocg is updated, weight_updated() is called
which in turn calls __propagate_weights() to update the active and inuse
weights so that the effective hierarchical weights are update accordingly.

The current implementation is incorrect for inner active nodes. For an
active leaf iocg, inuse can be any value between 1 and active and the
difference represents how much the iocg is donating. When weight is updated,
as long as inuse is clamped between 1 and the new weight, we're alright and
this is what __propagate_weights() currently implements.

However, that's not how an active inner node's inuse is set. An inner node's
inuse is solely determined by the ratio between the sums of inuse's and
active's of its children - ie. they're results of propagating the leaves'
active and inuse weights upwards. __propagate_weights() incorrectly applies
the same clamping as for a leaf when an active inner node's weight is
updated. Consider a hierarchy which looks like the following with saturating
workloads in AA and BB.

     R
   /   \
  A     B
  |     |
 AA     BB

1. For both A and B, active=100, inuse=100, hwa=0.5, hwi=0.5.

2. echo 200 &gt; A/io.weight

3. __propagate_weights() update A's active to 200 and leave inuse at 100 as
   it's already between 1 and the new active, making A:active=200,
   A:inuse=100. As R's active_sum is updated along with A's active,
   A:hwa=2/3, B:hwa=1/3. However, because the inuses didn't change, the
   hwi's remain unchanged at 0.5.

4. The weight of A is now twice that of B but AA and BB still have the same
   hwi of 0.5 and thus are doing the same amount of IOs.

Fix it by making __propgate_weights() always calculate the inuse of an
active inner iocg based on the ratio of child_inuse_sum to child_active_sum.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Dan Schatzberg &lt;dschatzberg@fb.com&gt;
Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost")
Cc: stable@vger.kernel.org # v5.4+
Link: https://lore.kernel.org/r/YJsxnLZV1MnBcqjj@slm.duckdns.org
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 e9f4eee9a0023ba22db9560d4cc6ee63f933dae8 upstream.

When the weight of an active iocg is updated, weight_updated() is called
which in turn calls __propagate_weights() to update the active and inuse
weights so that the effective hierarchical weights are update accordingly.

The current implementation is incorrect for inner active nodes. For an
active leaf iocg, inuse can be any value between 1 and active and the
difference represents how much the iocg is donating. When weight is updated,
as long as inuse is clamped between 1 and the new weight, we're alright and
this is what __propagate_weights() currently implements.

However, that's not how an active inner node's inuse is set. An inner node's
inuse is solely determined by the ratio between the sums of inuse's and
active's of its children - ie. they're results of propagating the leaves'
active and inuse weights upwards. __propagate_weights() incorrectly applies
the same clamping as for a leaf when an active inner node's weight is
updated. Consider a hierarchy which looks like the following with saturating
workloads in AA and BB.

     R
   /   \
  A     B
  |     |
 AA     BB

1. For both A and B, active=100, inuse=100, hwa=0.5, hwi=0.5.

2. echo 200 &gt; A/io.weight

3. __propagate_weights() update A's active to 200 and leave inuse at 100 as
   it's already between 1 and the new active, making A:active=200,
   A:inuse=100. As R's active_sum is updated along with A's active,
   A:hwa=2/3, B:hwa=1/3. However, because the inuses didn't change, the
   hwi's remain unchanged at 0.5.

4. The weight of A is now twice that of B but AA and BB still have the same
   hwi of 0.5 and thus are doing the same amount of IOs.

Fix it by making __propgate_weights() always calculate the inuse of an
active inner iocg based on the ratio of child_inuse_sum to child_active_sum.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Dan Schatzberg &lt;dschatzberg@fb.com&gt;
Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost")
Cc: stable@vger.kernel.org # v5.4+
Link: https://lore.kernel.org/r/YJsxnLZV1MnBcqjj@slm.duckdns.org
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: return -EBUSY when there are open partitions in blkdev_reread_part</title>
<updated>2021-04-28T11:41:48+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2021-04-21T16:05:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=785bdb3f1c1c83ee2f38afe8b0bc73f229fae598'/>
<id>785bdb3f1c1c83ee2f38afe8b0bc73f229fae598</id>
<content type='text'>
[ Upstream commit 68e6582e8f2dc32fd2458b9926564faa1fb4560e ]

The switch to go through blkdev_get_by_dev means we now ignore the
return value from bdev_disk_changed in __blkdev_get.  Add a manual
check to restore the old semantics.

Fixes: 4601b4b130de ("block: reopen the device in blkdev_reread_part")
Reported-by: Karel Zak &lt;kzak@redhat.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20210421160502.447418-1-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 68e6582e8f2dc32fd2458b9926564faa1fb4560e ]

The switch to go through blkdev_get_by_dev means we now ignore the
return value from bdev_disk_changed in __blkdev_get.  Add a manual
check to restore the old semantics.

Fixes: 4601b4b130de ("block: reopen the device in blkdev_reread_part")
Reported-by: Karel Zak &lt;kzak@redhat.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/r/20210421160502.447418-1-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: only update parent bi_status when bio fail</title>
<updated>2021-04-16T09:38:14+00:00</updated>
<author>
<name>Yufen Yu</name>
<email>yuyufen@huawei.com</email>
</author>
<published>2021-03-31T11:53:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e0e24b9fbc6ae5a9e1e1745a26e33cedaeb33030'/>
<id>e0e24b9fbc6ae5a9e1e1745a26e33cedaeb33030</id>
<content type='text'>
[ Upstream commit 3edf5346e4f2ce2fa0c94651a90a8dda169565ee ]

For multiple split bios, if one of the bio is fail, the whole
should return error to application. But we found there is a race
between bio_integrity_verify_fn and bio complete, which return
io success to application after one of the bio fail. The race as
following:

split bio(READ)          kworker

nvme_complete_rq
blk_update_request //split error=0
  bio_endio
    bio_integrity_endio
      queue_work(kintegrityd_wq, &amp;bip-&gt;bip_work);

                         bio_integrity_verify_fn
                         bio_endio //split bio
                          __bio_chain_endio
                             if (!parent-&gt;bi_status)

                               &lt;interrupt entry&gt;
                               nvme_irq
                                 blk_update_request //parent error=7
                                 req_bio_endio
                                    bio-&gt;bi_status = 7 //parent bio
                               &lt;interrupt exit&gt;

                               parent-&gt;bi_status = 0
                        parent-&gt;bi_end_io() // return bi_status=0

The bio has been split as two: split and parent. When split
bio completed, it depends on kworker to do endio, while
bio_integrity_verify_fn have been interrupted by parent bio
complete irq handler. Then, parent bio-&gt;bi_status which have
been set in irq handler will overwrite by kworker.

In fact, even without the above race, we also need to conside
the concurrency beteen mulitple split bio complete and update
the same parent bi_status. Normally, multiple split bios will
be issued to the same hctx and complete from the same irq
vector. But if we have updated queue map between multiple split
bios, these bios may complete on different hw queue and different
irq vector. Then the concurrency update parent bi_status may
cause the final status error.

Suggested-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20210331115359.1125679-1-yuyufen@huawei.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 3edf5346e4f2ce2fa0c94651a90a8dda169565ee ]

For multiple split bios, if one of the bio is fail, the whole
should return error to application. But we found there is a race
between bio_integrity_verify_fn and bio complete, which return
io success to application after one of the bio fail. The race as
following:

split bio(READ)          kworker

nvme_complete_rq
blk_update_request //split error=0
  bio_endio
    bio_integrity_endio
      queue_work(kintegrityd_wq, &amp;bip-&gt;bip_work);

                         bio_integrity_verify_fn
                         bio_endio //split bio
                          __bio_chain_endio
                             if (!parent-&gt;bi_status)

                               &lt;interrupt entry&gt;
                               nvme_irq
                                 blk_update_request //parent error=7
                                 req_bio_endio
                                    bio-&gt;bi_status = 7 //parent bio
                               &lt;interrupt exit&gt;

                               parent-&gt;bi_status = 0
                        parent-&gt;bi_end_io() // return bi_status=0

The bio has been split as two: split and parent. When split
bio completed, it depends on kworker to do endio, while
bio_integrity_verify_fn have been interrupted by parent bio
complete irq handler. Then, parent bio-&gt;bi_status which have
been set in irq handler will overwrite by kworker.

In fact, even without the above race, we also need to conside
the concurrency beteen mulitple split bio complete and update
the same parent bi_status. Normally, multiple split bios will
be issued to the same hctx and complete from the same irq
vector. But if we have updated queue map between multiple split
bios, these bios may complete on different hw queue and different
irq vector. Then the concurrency update parent bi_status may
cause the final status error.

Suggested-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20210331115359.1125679-1-yuyufen@huawei.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: recalculate segment count for multi-segment discards correctly</title>
<updated>2021-03-30T12:30:29+00:00</updated>
<author>
<name>David Jeffery</name>
<email>djeffery@redhat.com</email>
</author>
<published>2021-02-11T14:38:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4788e5bd988621ffd1b1765cb5966d951fc65531'/>
<id>4788e5bd988621ffd1b1765cb5966d951fc65531</id>
<content type='text'>
[ Upstream commit a958937ff166fc60d1c3a721036f6ff41bfa2821 ]

When a stacked block device inserts a request into another block device
using blk_insert_cloned_request, the request's nr_phys_segments field gets
recalculated by a call to blk_recalc_rq_segments in
blk_cloned_rq_check_limits. But blk_recalc_rq_segments does not know how to
handle multi-segment discards. For disk types which can handle
multi-segment discards like nvme, this results in discard requests which
claim a single segment when it should report several, triggering a warning
in nvme and causing nvme to fail the discard from the invalid state.

 WARNING: CPU: 5 PID: 191 at drivers/nvme/host/core.c:700 nvme_setup_discard+0x170/0x1e0 [nvme_core]
 ...
 nvme_setup_cmd+0x217/0x270 [nvme_core]
 nvme_loop_queue_rq+0x51/0x1b0 [nvme_loop]
 __blk_mq_try_issue_directly+0xe7/0x1b0
 blk_mq_request_issue_directly+0x41/0x70
 ? blk_account_io_start+0x40/0x50
 dm_mq_queue_rq+0x200/0x3e0
 blk_mq_dispatch_rq_list+0x10a/0x7d0
 ? __sbitmap_queue_get+0x25/0x90
 ? elv_rb_del+0x1f/0x30
 ? deadline_remove_request+0x55/0xb0
 ? dd_dispatch_request+0x181/0x210
 __blk_mq_do_dispatch_sched+0x144/0x290
 ? bio_attempt_discard_merge+0x134/0x1f0
 __blk_mq_sched_dispatch_requests+0x129/0x180
 blk_mq_sched_dispatch_requests+0x30/0x60
 __blk_mq_run_hw_queue+0x47/0xe0
 __blk_mq_delay_run_hw_queue+0x15b/0x170
 blk_mq_sched_insert_requests+0x68/0xe0
 blk_mq_flush_plug_list+0xf0/0x170
 blk_finish_plug+0x36/0x50
 xlog_cil_committed+0x19f/0x290 [xfs]
 xlog_cil_process_committed+0x57/0x80 [xfs]
 xlog_state_do_callback+0x1e0/0x2a0 [xfs]
 xlog_ioend_work+0x2f/0x80 [xfs]
 process_one_work+0x1b6/0x350
 worker_thread+0x53/0x3e0
 ? process_one_work+0x350/0x350
 kthread+0x11b/0x140
 ? __kthread_bind_mask+0x60/0x60
 ret_from_fork+0x22/0x30

This patch fixes blk_recalc_rq_segments to be aware of devices which can
have multi-segment discards. It calculates the correct discard segment
count by counting the number of bio as each discard bio is considered its
own segment.

Fixes: 1e739730c5b9 ("block: optionally merge discontiguous discard bios into a single request")
Signed-off-by: David Jeffery &lt;djeffery@redhat.com&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Reviewed-by: Laurence Oberman &lt;loberman@redhat.com&gt;
Link: https://lore.kernel.org/r/20210211143807.GA115624@redhat
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 a958937ff166fc60d1c3a721036f6ff41bfa2821 ]

When a stacked block device inserts a request into another block device
using blk_insert_cloned_request, the request's nr_phys_segments field gets
recalculated by a call to blk_recalc_rq_segments in
blk_cloned_rq_check_limits. But blk_recalc_rq_segments does not know how to
handle multi-segment discards. For disk types which can handle
multi-segment discards like nvme, this results in discard requests which
claim a single segment when it should report several, triggering a warning
in nvme and causing nvme to fail the discard from the invalid state.

 WARNING: CPU: 5 PID: 191 at drivers/nvme/host/core.c:700 nvme_setup_discard+0x170/0x1e0 [nvme_core]
 ...
 nvme_setup_cmd+0x217/0x270 [nvme_core]
 nvme_loop_queue_rq+0x51/0x1b0 [nvme_loop]
 __blk_mq_try_issue_directly+0xe7/0x1b0
 blk_mq_request_issue_directly+0x41/0x70
 ? blk_account_io_start+0x40/0x50
 dm_mq_queue_rq+0x200/0x3e0
 blk_mq_dispatch_rq_list+0x10a/0x7d0
 ? __sbitmap_queue_get+0x25/0x90
 ? elv_rb_del+0x1f/0x30
 ? deadline_remove_request+0x55/0xb0
 ? dd_dispatch_request+0x181/0x210
 __blk_mq_do_dispatch_sched+0x144/0x290
 ? bio_attempt_discard_merge+0x134/0x1f0
 __blk_mq_sched_dispatch_requests+0x129/0x180
 blk_mq_sched_dispatch_requests+0x30/0x60
 __blk_mq_run_hw_queue+0x47/0xe0
 __blk_mq_delay_run_hw_queue+0x15b/0x170
 blk_mq_sched_insert_requests+0x68/0xe0
 blk_mq_flush_plug_list+0xf0/0x170
 blk_finish_plug+0x36/0x50
 xlog_cil_committed+0x19f/0x290 [xfs]
 xlog_cil_process_committed+0x57/0x80 [xfs]
 xlog_state_do_callback+0x1e0/0x2a0 [xfs]
 xlog_ioend_work+0x2f/0x80 [xfs]
 process_one_work+0x1b6/0x350
 worker_thread+0x53/0x3e0
 ? process_one_work+0x350/0x350
 kthread+0x11b/0x140
 ? __kthread_bind_mask+0x60/0x60
 ret_from_fork+0x22/0x30

This patch fixes blk_recalc_rq_segments to be aware of devices which can
have multi-segment discards. It calculates the correct discard segment
count by counting the number of bio as each discard bio is considered its
own segment.

Fixes: 1e739730c5b9 ("block: optionally merge discontiguous discard bios into a single request")
Signed-off-by: David Jeffery &lt;djeffery@redhat.com&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Reviewed-by: Laurence Oberman &lt;loberman@redhat.com&gt;
Link: https://lore.kernel.org/r/20210211143807.GA115624@redhat
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: Suppress uevent for hidden device when removed</title>
<updated>2021-03-30T12:30:12+00:00</updated>
<author>
<name>Daniel Wagner</name>
<email>dwagner@suse.de</email>
</author>
<published>2021-03-11T15:19:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f614a7fbd4258644c3c664b8befa490de657c29e'/>
<id>f614a7fbd4258644c3c664b8befa490de657c29e</id>
<content type='text'>
[ Upstream commit 9ec491447b90ad6a4056a9656b13f0b3a1e83043 ]

register_disk() suppress uevents for devices with the GENHD_FL_HIDDEN
but enables uevents at the end again in order to announce disk after
possible partitions are created.

When the device is removed the uevents are still on and user land sees
'remove' messages for devices which were never 'add'ed to the system.

  KERNEL[95481.571887] remove   /devices/virtual/nvme-fabrics/ctl/nvme5/nvme0c5n1 (block)

Let's suppress the uevents for GENHD_FL_HIDDEN by not enabling the
uevents at all.

Signed-off-by: Daniel Wagner &lt;dwagner@suse.de&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Martin Wilck &lt;mwilck@suse.com&gt;
Link: https://lore.kernel.org/r/20210311151917.136091-1-dwagner@suse.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 9ec491447b90ad6a4056a9656b13f0b3a1e83043 ]

register_disk() suppress uevents for devices with the GENHD_FL_HIDDEN
but enables uevents at the end again in order to announce disk after
possible partitions are created.

When the device is removed the uevents are still on and user land sees
'remove' messages for devices which were never 'add'ed to the system.

  KERNEL[95481.571887] remove   /devices/virtual/nvme-fabrics/ctl/nvme5/nvme0c5n1 (block)

Let's suppress the uevents for GENHD_FL_HIDDEN by not enabling the
uevents at all.

Signed-off-by: Daniel Wagner &lt;dwagner@suse.de&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Martin Wilck &lt;mwilck@suse.com&gt;
Link: https://lore.kernel.org/r/20210311151917.136091-1-dwagner@suse.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: Fix REQ_OP_ZONE_RESET_ALL handling</title>
<updated>2021-03-30T12:30:10+00:00</updated>
<author>
<name>Damien Le Moal</name>
<email>damien.lemoal@wdc.com</email>
</author>
<published>2021-03-10T09:09:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0867825dd012d73a59ad8411047ac9ccfaf8c212'/>
<id>0867825dd012d73a59ad8411047ac9ccfaf8c212</id>
<content type='text'>
[ Upstream commit faa44c69daf9ccbd5b8a1aee13e0e0d037c0be17 ]

Similarly to a single zone reset operation (REQ_OP_ZONE_RESET), execute
REQ_OP_ZONE_RESET_ALL operations with REQ_SYNC set.

Signed-off-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
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 faa44c69daf9ccbd5b8a1aee13e0e0d037c0be17 ]

Similarly to a single zone reset operation (REQ_OP_ZONE_RESET), execute
REQ_OP_ZONE_RESET_ALL operations with REQ_SYNC set.

Signed-off-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
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-cgroup: Fix the recursive blkg rwstat</title>
<updated>2021-03-30T12:30:07+00:00</updated>
<author>
<name>Xunlei Pang</name>
<email>xlpang@linux.alibaba.com</email>
</author>
<published>2021-03-05T08:13:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5b78d2f59e26bbc20ab7e781c432d53add815e92'/>
<id>5b78d2f59e26bbc20ab7e781c432d53add815e92</id>
<content type='text'>
[ Upstream commit 4f44657d74873735e93a50eb25014721a66aac19 ]

The current blkio.throttle.io_service_bytes_recursive doesn't
work correctly.

As an example, for the following blkcg hierarchy:
 (Made 1GB READ in test1, 512MB READ in test2)
     test
    /    \
 test1   test2

$ head -n 1 test/test1/blkio.throttle.io_service_bytes_recursive
8:0 Read 1073684480
$ head -n 1 test/test2/blkio.throttle.io_service_bytes_recursive
8:0 Read 537448448
$ head -n 1 test/blkio.throttle.io_service_bytes_recursive
8:0 Read 537448448

Clearly, above data of "test" reflects "test2" not "test1"+"test2".

Do the correct summary in blkg_rwstat_recursive_sum().

Signed-off-by: Xunlei Pang &lt;xlpang@linux.alibaba.com&gt;
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 4f44657d74873735e93a50eb25014721a66aac19 ]

The current blkio.throttle.io_service_bytes_recursive doesn't
work correctly.

As an example, for the following blkcg hierarchy:
 (Made 1GB READ in test1, 512MB READ in test2)
     test
    /    \
 test1   test2

$ head -n 1 test/test1/blkio.throttle.io_service_bytes_recursive
8:0 Read 1073684480
$ head -n 1 test/test2/blkio.throttle.io_service_bytes_recursive
8:0 Read 537448448
$ head -n 1 test/blkio.throttle.io_service_bytes_recursive
8:0 Read 537448448

Clearly, above data of "test" reflects "test2" not "test1"+"test2".

Do the correct summary in blkg_rwstat_recursive_sum().

Signed-off-by: Xunlei Pang &lt;xlpang@linux.alibaba.com&gt;
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>
