<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/md/raid5.c, branch v5.1-rc4</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block</title>
<updated>2019-03-16T19:36:39+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-16T19:36:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=11efae3506d882a8782bc89493a32e467defd6b9'/>
<id>11efae3506d882a8782bc89493a32e467defd6b9</id>
<content type='text'>
Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>md: Fix failed allocation of md_register_thread</title>
<updated>2019-03-12T17:15:18+00:00</updated>
<author>
<name>Aditya Pakki</name>
<email>pakki001@umn.edu</email>
</author>
<published>2019-03-04T22:48:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e406f12dde1a8375d77ea02d91f313fb1a9c6aec'/>
<id>e406f12dde1a8375d77ea02d91f313fb1a9c6aec</id>
<content type='text'>
mddev-&gt;sync_thread can be set to NULL on kzalloc failure downstream.
The patch checks for such a scenario and frees allocated resources.

Committer node:

Added similar fix to raid5.c, as suggested by Guoqing.

Cc: stable@vger.kernel.org # v3.16+
Acked-by: Guoqing Jiang &lt;gqjiang@suse.com&gt;
Signed-off-by: Aditya Pakki &lt;pakki001@umn.edu&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
mddev-&gt;sync_thread can be set to NULL on kzalloc failure downstream.
The patch checks for such a scenario and frees allocated resources.

Committer node:

Added similar fix to raid5.c, as suggested by Guoqing.

Cc: stable@vger.kernel.org # v3.16+
Acked-by: Guoqing Jiang &lt;gqjiang@suse.com&gt;
Signed-off-by: Aditya Pakki &lt;pakki001@umn.edu&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>raid5: set write hint for PPL</title>
<updated>2019-03-12T17:15:18+00:00</updated>
<author>
<name>Mariusz Dabrowski</name>
<email>mariusz.dabrowski@intel.com</email>
</author>
<published>2019-02-18T14:04:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a596d08677320925b69e70c0fdc4c0f59384a65e'/>
<id>a596d08677320925b69e70c0fdc4c0f59384a65e</id>
<content type='text'>
When the Partial Parity Log is enabled, circular buffer is used to store
PPL data. Each write to RAID device causes overwrite of data in this buffer
so some write_hint can be set to those request to help drives handle
garbage collection. This patch adds new sysfs attribute which can be used
to specify which write_hint should be assigned to PPL.

Acked-by: Guoqing Jiang &lt;gqjiang@suse.com&gt;
Signed-off-by: Mariusz Dabrowski &lt;mariusz.dabrowski@intel.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 the Partial Parity Log is enabled, circular buffer is used to store
PPL data. Each write to RAID device causes overwrite of data in this buffer
so some write_hint can be set to those request to help drives handle
garbage collection. This patch adds new sysfs attribute which can be used
to specify which write_hint should be assigned to PPL.

Acked-by: Guoqing Jiang &lt;gqjiang@suse.com&gt;
Signed-off-by: Mariusz Dabrowski &lt;mariusz.dabrowski@intel.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: convert to kvmalloc</title>
<updated>2019-03-12T17:04:02+00:00</updated>
<author>
<name>Kent Overstreet</name>
<email>kent.overstreet@gmail.com</email>
</author>
<published>2019-03-12T06:31:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b330e6a49dc3e9145de5c986b29bbbb884351e92'/>
<id>b330e6a49dc3e9145de5c986b29bbbb884351e92</id>
<content type='text'>
The code really just wants a big flat buffer, so just do that.

Link: http://lkml.kernel.org/r/20181217131929.11727-3-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet &lt;kent.overstreet@gmail.com&gt;
Reviewed-by: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Shaohua Li &lt;shli@kernel.org&gt;
Cc: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Eric Paris &lt;eparis@parisplace.org&gt;
Cc: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Cc: Neil Horman &lt;nhorman@tuxdriver.com&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Pravin B Shelar &lt;pshelar@ovn.org&gt;
Cc: Stephen Smalley &lt;sds@tycho.nsa.gov&gt;
Cc: Vlad Yasevich &lt;vyasevich@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The code really just wants a big flat buffer, so just do that.

Link: http://lkml.kernel.org/r/20181217131929.11727-3-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet &lt;kent.overstreet@gmail.com&gt;
Reviewed-by: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Shaohua Li &lt;shli@kernel.org&gt;
Cc: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Eric Paris &lt;eparis@parisplace.org&gt;
Cc: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Cc: Neil Horman &lt;nhorman@tuxdriver.com&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: Pravin B Shelar &lt;pshelar@ovn.org&gt;
Cc: Stephen Smalley &lt;sds@tycho.nsa.gov&gt;
Cc: Vlad Yasevich &lt;vyasevich@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: fix 'out of memory' during raid cache recovery</title>
<updated>2019-01-28T19:44:40+00:00</updated>
<author>
<name>Alexei Naberezhnov</name>
<email>anaberezhnov@fb.com</email>
</author>
<published>2018-03-27T23:54:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=483cbbeddd5fe2c80fd4141ff0748fa06c4ff146'/>
<id>483cbbeddd5fe2c80fd4141ff0748fa06c4ff146</id>
<content type='text'>
This fixes the case when md array assembly fails because of raid cache recovery
unable to allocate a stripe, despite attempts to replay stripes and increase
cache size. This happens because stripes released by r5c_recovery_replay_stripes
and raid5_set_cache_size don't become available for allocation immediately.
Released stripes first are placed on conf-&gt;released_stripes list and require
md thread to merge them on conf-&gt;inactive_list before they can be allocated.

Patch allows final allocation attempt during cache recovery to wait for
new stripes to become availabe for allocation.

Cc: linux-raid@vger.kernel.org
Cc: Shaohua Li &lt;shli@kernel.org&gt;
Cc: linux-stable &lt;stable@vger.kernel.org&gt; # 4.10+
Fixes: b4c625c67362 ("md/r5cache: r5cache recovery: part 1")
Signed-off-by: Alexei Naberezhnov &lt;anaberezhnov@fb.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>
This fixes the case when md array assembly fails because of raid cache recovery
unable to allocate a stripe, despite attempts to replay stripes and increase
cache size. This happens because stripes released by r5c_recovery_replay_stripes
and raid5_set_cache_size don't become available for allocation immediately.
Released stripes first are placed on conf-&gt;released_stripes list and require
md thread to merge them on conf-&gt;inactive_list before they can be allocated.

Patch allows final allocation attempt during cache recovery to wait for
new stripes to become availabe for allocation.

Cc: linux-raid@vger.kernel.org
Cc: Shaohua Li &lt;shli@kernel.org&gt;
Cc: linux-stable &lt;stable@vger.kernel.org&gt; # 4.10+
Fixes: b4c625c67362 ("md/r5cache: r5cache recovery: part 1")
Signed-off-by: Alexei Naberezhnov &lt;anaberezhnov@fb.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>raid5: block failing device if raid will be failed</title>
<updated>2018-09-28T18:13:15+00:00</updated>
<author>
<name>Mariusz Tkaczyk</name>
<email>mariusz.tkaczyk@intel.com</email>
</author>
<published>2018-09-04T13:08:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fb73b357fb985cc652a72a41541d25915c7f9635'/>
<id>fb73b357fb985cc652a72a41541d25915c7f9635</id>
<content type='text'>
Currently there is an inconsistency for failing the member drives
for arrays with different RAID levels. For RAID456 - there is a possibility
to fail all of the devices. However - for other RAID levels - kernel blocks
removing the member drive, if the operation results in array's FAIL state
(EBUSY is returned). For example - removing last drive from RAID1 is not
possible.
This kind of blocker was never implemented for raid456 and we cannot see
the reason why.

We had tested following patch and did not observe any regression, so do you
have any comments/reasons for current approach, or we can send the proper
patch for this?

Signed-off-by: Mariusz Tkaczyk &lt;mariusz.tkaczyk@intel.com&gt;
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently there is an inconsistency for failing the member drives
for arrays with different RAID levels. For RAID456 - there is a possibility
to fail all of the devices. However - for other RAID levels - kernel blocks
removing the member drive, if the operation results in array's FAIL state
(EBUSY is returned). For example - removing last drive from RAID1 is not
possible.
This kind of blocker was never implemented for raid456 and we cannot see
the reason why.

We had tested following patch and did not observe any regression, so do you
have any comments/reasons for current approach, or we can send the proper
patch for this?

Signed-off-by: Mariusz Tkaczyk &lt;mariusz.tkaczyk@intel.com&gt;
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5-cache: disable reshape completely</title>
<updated>2018-09-01T00:38:09+00:00</updated>
<author>
<name>Shaohua Li</name>
<email>shli@fb.com</email>
</author>
<published>2018-08-29T18:05:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e254de6bcf3f5b6e78a92ac95fb91acef8adfe1a'/>
<id>e254de6bcf3f5b6e78a92ac95fb91acef8adfe1a</id>
<content type='text'>
We don't support reshape yet if an array supports log device. Previously we
determine the fact by checking -&gt;log. However, -&gt;log could be NULL after a log
device is removed, but the array is still marked to support log device. Don't
allow reshape in this case too. User can disable log device support by setting
'consistency_policy' to 'resync' then do reshape.

Reported-by: Xiao Ni &lt;xni@redhat.com&gt;
Tested-by: Xiao Ni &lt;xni@redhat.com&gt;
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We don't support reshape yet if an array supports log device. Previously we
determine the fact by checking -&gt;log. However, -&gt;log could be NULL after a log
device is removed, but the array is still marked to support log device. Don't
allow reshape in this case too. User can disable log device support by setting
'consistency_policy' to 'resync' then do reshape.

Reported-by: Xiao Ni &lt;xni@redhat.com&gt;
Tested-by: Xiao Ni &lt;xni@redhat.com&gt;
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input</title>
<updated>2018-08-18T23:48:07+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-18T23:48:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=08b5fa819970c318e58ab638f497633c25971813'/>
<id>08b5fa819970c318e58ab638f497633c25971813</id>
<content type='text'>
Pull input updates from Dmitry Torokhov:

 - a new driver for Rohm BU21029 touch controller

 - new bitmap APIs: bitmap_alloc, bitmap_zalloc and bitmap_free

 - updates to Atmel, eeti. pxrc and iforce drivers

 - assorted driver cleanups and fixes.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (57 commits)
  MAINTAINERS: Add PhoenixRC Flight Controller Adapter
  Input: do not use WARN() in input_alloc_absinfo()
  Input: mark expected switch fall-throughs
  Input: raydium_i2c_ts - use true and false for boolean values
  Input: evdev - switch to bitmap API
  Input: gpio-keys - switch to bitmap_zalloc()
  Input: elan_i2c_smbus - cast sizeof to int for comparison
  bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()
  md: Avoid namespace collision with bitmap API
  dm: Avoid namespace collision with bitmap API
  Input: pm8941-pwrkey - add resin entry
  Input: pm8941-pwrkey - abstract register offsets and event code
  Input: iforce - reorganize joystick configuration lists
  Input: atmel_mxt_ts - move completion to after config crc is updated
  Input: atmel_mxt_ts - don't report zero pressure from T9
  Input: atmel_mxt_ts - zero terminate config firmware file
  Input: atmel_mxt_ts - refactor config update code to add context struct
  Input: atmel_mxt_ts - config CRC may start at T71
  Input: atmel_mxt_ts - remove unnecessary debug on ENOMEM
  Input: atmel_mxt_ts - remove duplicate setup of ABS_MT_PRESSURE
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull input updates from Dmitry Torokhov:

 - a new driver for Rohm BU21029 touch controller

 - new bitmap APIs: bitmap_alloc, bitmap_zalloc and bitmap_free

 - updates to Atmel, eeti. pxrc and iforce drivers

 - assorted driver cleanups and fixes.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (57 commits)
  MAINTAINERS: Add PhoenixRC Flight Controller Adapter
  Input: do not use WARN() in input_alloc_absinfo()
  Input: mark expected switch fall-throughs
  Input: raydium_i2c_ts - use true and false for boolean values
  Input: evdev - switch to bitmap API
  Input: gpio-keys - switch to bitmap_zalloc()
  Input: elan_i2c_smbus - cast sizeof to int for comparison
  bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()
  md: Avoid namespace collision with bitmap API
  dm: Avoid namespace collision with bitmap API
  Input: pm8941-pwrkey - add resin entry
  Input: pm8941-pwrkey - abstract register offsets and event code
  Input: iforce - reorganize joystick configuration lists
  Input: atmel_mxt_ts - move completion to after config crc is updated
  Input: atmel_mxt_ts - don't report zero pressure from T9
  Input: atmel_mxt_ts - zero terminate config firmware file
  Input: atmel_mxt_ts - refactor config update code to add context struct
  Input: atmel_mxt_ts - config CRC may start at T71
  Input: atmel_mxt_ts - remove unnecessary debug on ENOMEM
  Input: atmel_mxt_ts - remove duplicate setup of ABS_MT_PRESSURE
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>md/raid5: fix data corruption of replacements after originals dropped</title>
<updated>2018-08-02T18:22:06+00:00</updated>
<author>
<name>BingJing Chang</name>
<email>bingjingc@synology.com</email>
</author>
<published>2018-08-01T09:08:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d63e2fc804c46e50eee825c5d3a7228e07048b47'/>
<id>d63e2fc804c46e50eee825c5d3a7228e07048b47</id>
<content type='text'>
During raid5 replacement, the stripes can be marked with R5_NeedReplace
flag. Data can be read from being-replaced devices and written to
replacing spares without reading all other devices. (It's 'replace'
mode. s.replacing = 1) If a being-replaced device is dropped, the
replacement progress will be interrupted and resumed with pure recovery
mode. However, existing stripes before being interrupted cannot read
from the dropped device anymore. It prints lots of WARN_ON messages.
And it results in data corruption because existing stripes write
problematic data into its replacement device and update the progress.

\# Erase disks (1MB + 2GB)
dd if=/dev/zero of=/dev/sda bs=1MB count=2049
dd if=/dev/zero of=/dev/sdb bs=1MB count=2049
dd if=/dev/zero of=/dev/sdc bs=1MB count=2049
dd if=/dev/zero of=/dev/sdd bs=1MB count=2049
mdadm -C /dev/md0 -amd -R -l5 -n3 -x0 /dev/sd[abc] -z 2097152
\# Ensure array stores non-zero data
dd if=/root/data_4GB.iso of=/dev/md0 bs=1MB
\# Start replacement
mdadm /dev/md0 -a /dev/sdd
mdadm /dev/md0 --replace /dev/sda

Then, Hot-plug out /dev/sda during recovery, and wait for recovery done.
echo check &gt; /sys/block/md0/md/sync_action
cat /sys/block/md0/md/mismatch_cnt # it will be greater than 0.

Soon after you hot-plug out /dev/sda, you will see many WARN_ON
messages. The replacement recovery will be interrupted shortly. After
the recovery finishes, it will result in data corruption.

Actually, it's just an unhandled case of replacement. In commit
&lt;f94c0b6658c7&gt; (md/raid5: fix interaction of 'replace' and 'recovery'.),
if a NeedReplace device is not UPTODATE then that is an error, the
commit just simply print WARN_ON but also mark these corrupted stripes
with R5_WantReplace. (it means it's ready for writes.)

To fix this case, we can leverage 'sync and replace' mode mentioned in
commit &lt;9a3e1101b827&gt; (md/raid5: detect and handle replacements during
recovery.). We can add logics to detect and use 'sync and replace' mode
for these stripes.

Reported-by: Alex Chen &lt;alexchen@synology.com&gt;
Reviewed-by: Alex Wu &lt;alexwu@synology.com&gt;
Reviewed-by: Chung-Chiang Cheng &lt;cccheng@synology.com&gt;
Signed-off-by: BingJing Chang &lt;bingjingc@synology.com&gt;
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
</content>
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During raid5 replacement, the stripes can be marked with R5_NeedReplace
flag. Data can be read from being-replaced devices and written to
replacing spares without reading all other devices. (It's 'replace'
mode. s.replacing = 1) If a being-replaced device is dropped, the
replacement progress will be interrupted and resumed with pure recovery
mode. However, existing stripes before being interrupted cannot read
from the dropped device anymore. It prints lots of WARN_ON messages.
And it results in data corruption because existing stripes write
problematic data into its replacement device and update the progress.

\# Erase disks (1MB + 2GB)
dd if=/dev/zero of=/dev/sda bs=1MB count=2049
dd if=/dev/zero of=/dev/sdb bs=1MB count=2049
dd if=/dev/zero of=/dev/sdc bs=1MB count=2049
dd if=/dev/zero of=/dev/sdd bs=1MB count=2049
mdadm -C /dev/md0 -amd -R -l5 -n3 -x0 /dev/sd[abc] -z 2097152
\# Ensure array stores non-zero data
dd if=/root/data_4GB.iso of=/dev/md0 bs=1MB
\# Start replacement
mdadm /dev/md0 -a /dev/sdd
mdadm /dev/md0 --replace /dev/sda

Then, Hot-plug out /dev/sda during recovery, and wait for recovery done.
echo check &gt; /sys/block/md0/md/sync_action
cat /sys/block/md0/md/mismatch_cnt # it will be greater than 0.

Soon after you hot-plug out /dev/sda, you will see many WARN_ON
messages. The replacement recovery will be interrupted shortly. After
the recovery finishes, it will result in data corruption.

Actually, it's just an unhandled case of replacement. In commit
&lt;f94c0b6658c7&gt; (md/raid5: fix interaction of 'replace' and 'recovery'.),
if a NeedReplace device is not UPTODATE then that is an error, the
commit just simply print WARN_ON but also mark these corrupted stripes
with R5_WantReplace. (it means it's ready for writes.)

To fix this case, we can leverage 'sync and replace' mode mentioned in
commit &lt;9a3e1101b827&gt; (md/raid5: detect and handle replacements during
recovery.). We can add logics to detect and use 'sync and replace' mode
for these stripes.

Reported-by: Alex Chen &lt;alexchen@synology.com&gt;
Reviewed-by: Alex Wu &lt;alexwu@synology.com&gt;
Reviewed-by: Chung-Chiang Cheng &lt;cccheng@synology.com&gt;
Signed-off-by: BingJing Chang &lt;bingjingc@synology.com&gt;
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
</pre>
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</entry>
<entry>
<title>md: Avoid namespace collision with bitmap API</title>
<updated>2018-08-01T22:49:39+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2018-08-01T22:20:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e64e4018d572710c44f42c923d4ac059f0a23320'/>
<id>e64e4018d572710c44f42c923d4ac059f0a23320</id>
<content type='text'>
bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods.

On the other hand MD bitmap API is special case.
Adding 'md' prefix to it to avoid name space collision.

No functional changes intended.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Acked-by: Shaohua Li &lt;shli@kernel.org&gt;
Signed-off-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;</content>
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<pre>
bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods.

On the other hand MD bitmap API is special case.
Adding 'md' prefix to it to avoid name space collision.

No functional changes intended.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Acked-by: Shaohua Li &lt;shli@kernel.org&gt;
Signed-off-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;</pre>
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