<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/md/raid5.c, branch v5.12</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'for-5.12/drivers-2021-02-17' of git://git.kernel.dk/linux-block</title>
<updated>2021-02-21T19:06:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-02-21T19:06:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9820b4dca0f9c6b7ab8b4307286cdace171b724d'/>
<id>9820b4dca0f9c6b7ab8b4307286cdace171b724d</id>
<content type='text'>
Pull block driver updates from Jens Axboe:

 - Remove the skd driver. It's been EOL for a long time (Damien)

 - NVMe pull requests
      - fix multipath handling of -&gt;queue_rq errors (Chao Leng)
      - nvmet cleanups (Chaitanya Kulkarni)
      - add a quirk for buggy Amazon controller (Filippo Sironi)
      - avoid devm allocations in nvme-hwmon that don't interact well
        with fabrics (Hannes Reinecke)
      - sysfs cleanups (Jiapeng Chong)
      - fix nr_zones for multipath (Keith Busch)
      - nvme-tcp crash fix for no-data commands (Sagi Grimberg)
      - nvmet-tcp fixes (Sagi Grimberg)
      - add a missing __rcu annotation (Christoph)
      - failed reconnect fixes (Chao Leng)
      - various tracing improvements (Michal Krakowiak, Johannes
        Thumshirn)
      - switch the nvmet-fc assoc_list to use RCU protection (Leonid
        Ravich)
      - resync the status codes with the latest spec (Max Gurtovoy)
      - minor nvme-tcp improvements (Sagi Grimberg)
      - various cleanups (Rikard Falkeborn, Minwoo Im, Chaitanya
        Kulkarni, Israel Rukshin)

 - Floppy O_NDELAY fix (Denis)

 - MD pull request
      - raid5 chunk_sectors fix (Guoqing)

 - Use lore links (Kees)

 - Use DEFINE_SHOW_ATTRIBUTE for nbd (Liao)

 - loop lock scaling (Pavel)

 - mtip32xx PCI fixes (Bjorn)

 - bcache fixes (Kai, Dongdong)

 - Misc fixes (Tian, Yang, Guoqing, Joe, Andy)

* tag 'for-5.12/drivers-2021-02-17' of git://git.kernel.dk/linux-block: (64 commits)
  lightnvm: pblk: Replace guid_copy() with export_guid()/import_guid()
  lightnvm: fix unnecessary NULL check warnings
  nvme-tcp: fix crash triggered with a dataless request submission
  block: Replace lkml.org links with lore
  nbd: Convert to DEFINE_SHOW_ATTRIBUTE
  nvme: add 48-bit DMA address quirk for Amazon NVMe controllers
  nvme-hwmon: rework to avoid devm allocation
  nvmet: remove else at the end of the function
  nvmet: add nvmet_req_subsys() helper
  nvmet: use min of device_path and disk len
  nvmet: use invalid cmd opcode helper
  nvmet: use invalid cmd opcode helper
  nvmet: add helper to report invalid opcode
  nvmet: remove extra variable in id-ns handler
  nvmet: make nvmet_find_namespace() req based
  nvmet: return uniform error for invalid ns
  nvmet: set status to 0 in case for invalid nsid
  nvmet-fc: add a missing __rcu annotation to nvmet_fc_tgt_assoc.queues
  nvme-multipath: set nr_zones for zoned namespaces
  nvmet-tcp: fix potential race of tcp socket closing accept_work
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block driver updates from Jens Axboe:

 - Remove the skd driver. It's been EOL for a long time (Damien)

 - NVMe pull requests
      - fix multipath handling of -&gt;queue_rq errors (Chao Leng)
      - nvmet cleanups (Chaitanya Kulkarni)
      - add a quirk for buggy Amazon controller (Filippo Sironi)
      - avoid devm allocations in nvme-hwmon that don't interact well
        with fabrics (Hannes Reinecke)
      - sysfs cleanups (Jiapeng Chong)
      - fix nr_zones for multipath (Keith Busch)
      - nvme-tcp crash fix for no-data commands (Sagi Grimberg)
      - nvmet-tcp fixes (Sagi Grimberg)
      - add a missing __rcu annotation (Christoph)
      - failed reconnect fixes (Chao Leng)
      - various tracing improvements (Michal Krakowiak, Johannes
        Thumshirn)
      - switch the nvmet-fc assoc_list to use RCU protection (Leonid
        Ravich)
      - resync the status codes with the latest spec (Max Gurtovoy)
      - minor nvme-tcp improvements (Sagi Grimberg)
      - various cleanups (Rikard Falkeborn, Minwoo Im, Chaitanya
        Kulkarni, Israel Rukshin)

 - Floppy O_NDELAY fix (Denis)

 - MD pull request
      - raid5 chunk_sectors fix (Guoqing)

 - Use lore links (Kees)

 - Use DEFINE_SHOW_ATTRIBUTE for nbd (Liao)

 - loop lock scaling (Pavel)

 - mtip32xx PCI fixes (Bjorn)

 - bcache fixes (Kai, Dongdong)

 - Misc fixes (Tian, Yang, Guoqing, Joe, Andy)

* tag 'for-5.12/drivers-2021-02-17' of git://git.kernel.dk/linux-block: (64 commits)
  lightnvm: pblk: Replace guid_copy() with export_guid()/import_guid()
  lightnvm: fix unnecessary NULL check warnings
  nvme-tcp: fix crash triggered with a dataless request submission
  block: Replace lkml.org links with lore
  nbd: Convert to DEFINE_SHOW_ATTRIBUTE
  nvme: add 48-bit DMA address quirk for Amazon NVMe controllers
  nvme-hwmon: rework to avoid devm allocation
  nvmet: remove else at the end of the function
  nvmet: add nvmet_req_subsys() helper
  nvmet: use min of device_path and disk len
  nvmet: use invalid cmd opcode helper
  nvmet: use invalid cmd opcode helper
  nvmet: add helper to report invalid opcode
  nvmet: remove extra variable in id-ns handler
  nvmet: make nvmet_find_namespace() req based
  nvmet: return uniform error for invalid ns
  nvmet: set status to 0 in case for invalid nsid
  nvmet-fc: add a missing __rcu annotation to nvmet_fc_tgt_assoc.queues
  nvme-multipath: set nr_zones for zoned namespaces
  nvmet-tcp: fix potential race of tcp socket closing accept_work
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: cast chunk_sectors to sector_t value</title>
<updated>2021-02-04T06:48:16+00:00</updated>
<author>
<name>Guoqing Jiang</name>
<email>guoqing.jiang@cloud.ionos.com</email>
</author>
<published>2020-12-16T01:26:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c5eec74f252dfba25269cd68f9a3407aedefd330'/>
<id>c5eec74f252dfba25269cd68f9a3407aedefd330</id>
<content type='text'>
Currently, raid5 calculates dev_sectors from chunk_sectors without
proper cast, which is problematic.

Signed-off-by: Guoqing Jiang &lt;guoqing.jiang@cloud.ionos.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, raid5 calculates dev_sectors from chunk_sectors without
proper cast, which is problematic.

Signed-off-by: Guoqing Jiang &lt;guoqing.jiang@cloud.ionos.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid6: refactor raid5_read_one_chunk</title>
<updated>2021-01-27T16:51:48+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2021-01-26T14:52:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e82ed3a4fbb54b2d7dcb2a7733520f3e10b97abf'/>
<id>e82ed3a4fbb54b2d7dcb2a7733520f3e10b97abf</id>
<content type='text'>
Refactor raid5_read_one_chunk so that all simple checks are done
before allocating the bio.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Song Liu &lt;song@kernel.org&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Reviewed-by: Chaitanya Kulkarni &lt;chaitanya.kulkarni@wdc.com&gt;
Acked-by: Damien Le Moal &lt;damien.lemoal@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>
Refactor raid5_read_one_chunk so that all simple checks are done
before allocating the bio.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Song Liu &lt;song@kernel.org&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Reviewed-by: Chaitanya Kulkarni &lt;chaitanya.kulkarni@wdc.com&gt;
Acked-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: store a block_device pointer in struct bio</title>
<updated>2021-01-25T01:17:20+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2021-01-24T10:02:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=309dca309fc39a9e3c31b916393b74bd174fd74e'/>
<id>309dca309fc39a9e3c31b916393b74bd174fd74e</id>
<content type='text'>
Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: remove the request_queue argument to the block_bio_remap tracepoint</title>
<updated>2020-12-04T16:42:00+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-12-03T16:21:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1c02fca620f7273b597591065d366e2cca948d8f'/>
<id>1c02fca620f7273b597591065d366e2cca948d8f</id>
<content type='text'>
The request_queue can trivially be derived from the bio.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Reviewed-by: Chaitanya Kulkarni &lt;chaitanya.kulkarni@wdc.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The request_queue can trivially be derived from the bio.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Reviewed-by: Chaitanya Kulkarni &lt;chaitanya.kulkarni@wdc.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: fix oops during stripe resizing</title>
<updated>2020-10-09T05:38:10+00:00</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2020-10-05T16:35:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b44c018cdf748b96b676ba09fdbc5b34fc443ada'/>
<id>b44c018cdf748b96b676ba09fdbc5b34fc443ada</id>
<content type='text'>
KoWei reported crash during raid5 reshape:

[ 1032.252932] Oops: 0002 [#1] SMP PTI
[...]
[ 1032.252943] RIP: 0010:memcpy_erms+0x6/0x10
[...]
[ 1032.252947] RSP: 0018:ffffba1ac0c03b78 EFLAGS: 00010286
[ 1032.252949] RAX: 0000784ac0000000 RBX: ffff91bec3d09740 RCX: 0000000000001000
[ 1032.252951] RDX: 0000000000001000 RSI: ffff91be6781c000 RDI: 0000784ac0000000
[ 1032.252953] RBP: ffffba1ac0c03bd8 R08: 0000000000001000 R09: ffffba1ac0c03bf8
[ 1032.252954] R10: 0000000000000000 R11: 0000000000000000 R12: ffffba1ac0c03bf8
[ 1032.252955] R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000000
[ 1032.252958] FS:  0000000000000000(0000) GS:ffff91becf500000(0000) knlGS:0000000000000000
[ 1032.252959] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1032.252961] CR2: 0000784ac0000000 CR3: 000000031780a002 CR4: 00000000001606e0
[ 1032.252962] Call Trace:
[ 1032.252969]  ? async_memcpy+0x179/0x1000 [async_memcpy]
[ 1032.252977]  ? raid5_release_stripe+0x8e/0x110 [raid456]
[ 1032.252982]  handle_stripe_expansion+0x15a/0x1f0 [raid456]
[ 1032.252988]  handle_stripe+0x592/0x1270 [raid456]
[ 1032.252993]  handle_active_stripes.isra.0+0x3cb/0x5a0 [raid456]
[ 1032.252999]  raid5d+0x35c/0x550 [raid456]
[ 1032.253002]  ? schedule+0x42/0xb0
[ 1032.253006]  ? schedule_timeout+0x10e/0x160
[ 1032.253011]  md_thread+0x97/0x160
[ 1032.253015]  ? wait_woken+0x80/0x80
[ 1032.253019]  kthread+0x104/0x140
[ 1032.253022]  ? md_start_sync+0x60/0x60
[ 1032.253024]  ? kthread_park+0x90/0x90
[ 1032.253027]  ret_from_fork+0x35/0x40

This is because cache_size_mutex was unlocked too early in resize_stripes,
which races with grow_one_stripe() that grow_one_stripe() allocates a
stripe with wrong pool_size.

Fix this issue by unlocking cache_size_mutex after updating pool_size.

Cc: &lt;stable@vger.kernel.org&gt; # v4.4+
Reported-by: KoWei Sung &lt;winders@amazon.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
KoWei reported crash during raid5 reshape:

[ 1032.252932] Oops: 0002 [#1] SMP PTI
[...]
[ 1032.252943] RIP: 0010:memcpy_erms+0x6/0x10
[...]
[ 1032.252947] RSP: 0018:ffffba1ac0c03b78 EFLAGS: 00010286
[ 1032.252949] RAX: 0000784ac0000000 RBX: ffff91bec3d09740 RCX: 0000000000001000
[ 1032.252951] RDX: 0000000000001000 RSI: ffff91be6781c000 RDI: 0000784ac0000000
[ 1032.252953] RBP: ffffba1ac0c03bd8 R08: 0000000000001000 R09: ffffba1ac0c03bf8
[ 1032.252954] R10: 0000000000000000 R11: 0000000000000000 R12: ffffba1ac0c03bf8
[ 1032.252955] R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000000
[ 1032.252958] FS:  0000000000000000(0000) GS:ffff91becf500000(0000) knlGS:0000000000000000
[ 1032.252959] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1032.252961] CR2: 0000784ac0000000 CR3: 000000031780a002 CR4: 00000000001606e0
[ 1032.252962] Call Trace:
[ 1032.252969]  ? async_memcpy+0x179/0x1000 [async_memcpy]
[ 1032.252977]  ? raid5_release_stripe+0x8e/0x110 [raid456]
[ 1032.252982]  handle_stripe_expansion+0x15a/0x1f0 [raid456]
[ 1032.252988]  handle_stripe+0x592/0x1270 [raid456]
[ 1032.252993]  handle_active_stripes.isra.0+0x3cb/0x5a0 [raid456]
[ 1032.252999]  raid5d+0x35c/0x550 [raid456]
[ 1032.253002]  ? schedule+0x42/0xb0
[ 1032.253006]  ? schedule_timeout+0x10e/0x160
[ 1032.253011]  md_thread+0x97/0x160
[ 1032.253015]  ? wait_woken+0x80/0x80
[ 1032.253019]  kthread+0x104/0x140
[ 1032.253022]  ? md_start_sync+0x60/0x60
[ 1032.253024]  ? kthread_park+0x90/0x90
[ 1032.253027]  ret_from_fork+0x35/0x40

This is because cache_size_mutex was unlocked too early in resize_stripes,
which races with grow_one_stripe() that grow_one_stripe() allocates a
stripe with wrong pool_size.

Fix this issue by unlocking cache_size_mutex after updating pool_size.

Cc: &lt;stable@vger.kernel.org&gt; # v4.4+
Reported-by: KoWei Sung &lt;winders@amazon.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: reallocate page array after setting new stripe_size</title>
<updated>2020-09-24T23:44:45+00:00</updated>
<author>
<name>Yufen Yu</name>
<email>yuyufen@huawei.com</email>
</author>
<published>2020-08-20T13:22:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=389125844352c784abf8c186589343466d03cd6a'/>
<id>389125844352c784abf8c186589343466d03cd6a</id>
<content type='text'>
When try to resize stripe_size, we also need to free old
shared page array and allocate new.

Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When try to resize stripe_size, we also need to free old
shared page array and allocate new.

Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: resize stripe_head when reshape array</title>
<updated>2020-09-24T23:44:45+00:00</updated>
<author>
<name>Yufen Yu</name>
<email>yuyufen@huawei.com</email>
</author>
<published>2020-08-20T13:22:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f16acaf328c5615fdaea74f9bd0b4019544532d6'/>
<id>f16acaf328c5615fdaea74f9bd0b4019544532d6</id>
<content type='text'>
When reshape array, we try to reuse shared pages of old stripe_head,
and allocate more for the new one if needed.

Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When reshape array, we try to reuse shared pages of old stripe_head,
and allocate more for the new one if needed.

Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: let multiple devices of stripe_head share page</title>
<updated>2020-09-24T23:44:44+00:00</updated>
<author>
<name>Yufen Yu</name>
<email>yuyufen@huawei.com</email>
</author>
<published>2020-08-20T13:22:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=046169f048cdea84fd327469239e2dfa317981b5'/>
<id>046169f048cdea84fd327469239e2dfa317981b5</id>
<content type='text'>
In current implementation, grow_buffers() uses alloc_page() to
allocate the buffers for each stripe_head, i.e. allocate a page
for each dev[i] in stripe_head.

After setting stripe_size as a configurable value by writing
sysfs entry, it means that we always allocate 64K buffers, but
just use 4K of them when stripe_size is 4K in 64KB arm64.

To avoid wasting memory, we try to let multiple sh-&gt;dev share
one real page. That means, multiple sh-&gt;dev[i].page will point
to the only page with different offset. Example of 64K PAGE_SIZE
and 4K stripe_size as following:

                    64K PAGE_SIZE
          +---+---+---+---+------------------------------+
          |   |   |   |   |
          |   |   |   |   |
          +-+-+-+-+-+-+-+-+------------------------------+
            ^   ^   ^   ^
            |   |   |   +----------------------------+
            |   |   |                                |
            |   |   +-------------------+            |
            |   |                       |            |
            |   +----------+            |            |
            |              |            |            |
            +-+            |            |            |
              |            |            |            |
        +-----+-----+------+-----+------+-----+------+------+
sh      | offset(0) | offset(4K) | offset(8K) | offset(12K) |
 +      +-----------+------------+------------+-------------+
 +----&gt; dev[0].page  dev[1].page  dev[2].page  dev[3].page

A new 'pages' array will be added into stripe_head to record shared
page used by this stripe_head. Allocate them when grow_buffers()
and free them when shrink_buffers().

After trying to share page, the users of sh-&gt;dev[i].page need to take
care of the related page offset: page of issued bio and page passed
to xor compution functions. But thanks for previous different page offset
supported. Here, we just need to set correct dev[i].offset.

Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In current implementation, grow_buffers() uses alloc_page() to
allocate the buffers for each stripe_head, i.e. allocate a page
for each dev[i] in stripe_head.

After setting stripe_size as a configurable value by writing
sysfs entry, it means that we always allocate 64K buffers, but
just use 4K of them when stripe_size is 4K in 64KB arm64.

To avoid wasting memory, we try to let multiple sh-&gt;dev share
one real page. That means, multiple sh-&gt;dev[i].page will point
to the only page with different offset. Example of 64K PAGE_SIZE
and 4K stripe_size as following:

                    64K PAGE_SIZE
          +---+---+---+---+------------------------------+
          |   |   |   |   |
          |   |   |   |   |
          +-+-+-+-+-+-+-+-+------------------------------+
            ^   ^   ^   ^
            |   |   |   +----------------------------+
            |   |   |                                |
            |   |   +-------------------+            |
            |   |                       |            |
            |   +----------+            |            |
            |              |            |            |
            +-+            |            |            |
              |            |            |            |
        +-----+-----+------+-----+------+-----+------+------+
sh      | offset(0) | offset(4K) | offset(8K) | offset(12K) |
 +      +-----------+------------+------------+-------------+
 +----&gt; dev[0].page  dev[1].page  dev[2].page  dev[3].page

A new 'pages' array will be added into stripe_head to record shared
page used by this stripe_head. Allocate them when grow_buffers()
and free them when shrink_buffers().

After trying to share page, the users of sh-&gt;dev[i].page need to take
care of the related page offset: page of issued bio and page passed
to xor compution functions. But thanks for previous different page offset
supported. Here, we just need to set correct dev[i].offset.

Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid6: let async recovery function support different page offset</title>
<updated>2020-09-24T23:44:44+00:00</updated>
<author>
<name>Yufen Yu</name>
<email>yuyufen@huawei.com</email>
</author>
<published>2020-08-20T13:22:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4f86ff5580fa692f850f37f948c73814a24a722b'/>
<id>4f86ff5580fa692f850f37f948c73814a24a722b</id>
<content type='text'>
For now, asynchronous raid6 recovery calculate functions are require
common offset for pages. But, we expect them to support different page
offset after introducing stripe shared page. Do that by simplily adding
page offset where each page address are referred. Then, replace the
old interface with the new ones in raid6 and raid6test.

Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For now, asynchronous raid6 recovery calculate functions are require
common offset for pages. But, we expect them to support different page
offset after introducing stripe shared page. Do that by simplily adding
page offset where each page address are referred. Then, replace the
old interface with the new ones in raid6 and raid6test.

Signed-off-by: Yufen Yu &lt;yuyufen@huawei.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
