linux-stable.git/drivers/md/dm-raid.c, branch linux-3.16.y

dm raid: fix round up of default region size

2015-10-30T13:59:28+00:00

commit 042745ee53a0a7c1f5aff191a4a24213c6dcfb52 upstream.

Commit 3a0f9aaee028 ("dm raid: round region_size to power of two")
intended to make sure that the default region size is a power of two.
However, the logic in that commit is incorrect and sets the variable
region_size to 0 or 1, depending on whether min_region_size is a power
of two.

Fix this logic, using roundup_pow_of_two(), so that region_size is
properly rounded up to the next power of two.

Signed-off-by: Mikulas Patocka 
Fixes: 3a0f9aaee028 ("dm raid: round region_size to power of two")
Signed-off-by: Mike Snitzer 
Signed-off-by: Luis Henriques

dm raid: ensure superblock's size matches device's logical block size

2014-11-20T12:01:49+00:00

commit 40d43c4b4cac4c2647bf07110d7b07d35f399a84 upstream.

The dm-raid superblock (struct dm_raid_superblock) is padded to 512
bytes and that size is being used to read it in from the metadata
device into one preallocated page.

Reading or writing this on a 512-byte sector device works fine but on
a 4096-byte sector device this fails.

Set the dm-raid superblock's size to the logical block size of the
metadata device, because IO at that size is guaranteed too work.  Also
add a size check to avoid silent partial metadata loss in case the
superblock should ever grow past the logical block size or PAGE_SIZE.

[includes pointer math fix from Dan Carpenter]
Reported-by: "Liuhua Wang" 
Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Dan Carpenter 
Signed-off-by: Mike Snitzer 
Signed-off-by: Luis Henriques

MD: Remember the last sync operation that was performed

2013-06-26T02:38:24+00:00

MD:  Remember the last sync operation that was performed

This patch adds a field to the mddev structure to track the last
sync operation that was performed.  This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs.  If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check.  If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired.  etc.

Signed-off-by: Jonathan Brassow 
Signed-off-by: NeilBrown

md: replace strict_strto() with kstrto()

2013-06-13T22:10:26+00:00

The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.

Signed-off-by: Jingoo Han 
Signed-off-by: NeilBrown

dm-raid: silence compiler warning on rebuilds_per_group.

2013-06-13T22:10:26+00:00

This doesn't really need to be initialised, but it doesn't hurt,
silences the compiler, and as it is a counter it makes sense for it to
start at zero.

Signed-off-by: NeilBrown

DM RAID: Fix raid_resume not reviving failed devices in all cases

2013-06-13T22:10:25+00:00

DM RAID:  Fix raid_resume not reviving failed devices in all cases

When a device fails in a RAID array, it is marked as Faulty.  Later,
md_check_recovery is called which (through the call chain) calls
'hot_remove_disk' in order to have the personalities remove the device
from use in the array.

Sometimes, it is possible for the array to be suspended before the
personalities get their chance to perform 'hot_remove_disk'.  This is
normally not an issue.  If the array is deactivated, then the failed
device will be noticed when the array is reinstantiated.  If the
array is resumed and the disk is still missing, md_check_recovery will
be called upon resume and 'hot_remove_disk' will be called at that
time.  However, (for dm-raid) if the device has been restored,
a resume on the array would cause it to attempt to revive the device
by calling 'hot_add_disk'.  If 'hot_remove_disk' had not been called,
a situation is then created where the device is thought to concurrently
be the replacement and the device to be replaced.  Thus, the device
is first sync'ed with the rest of the array (because it is the replacement
device) and then marked Faulty and removed from the array (because
it is also the device being replaced).

The solution is to check and see if the device had properly been removed
before the array was suspended.  This is done by seeing whether the
device's 'raid_disk' field is -1 - a condition that implies that
'md_check_recovery -> remove_and_add_spares (where raid_disk is set to -1)
-> hot_remove_disk' has been called.  If 'raid_disk' is not -1, then
'hot_remove_disk' must be called to complete the removal of the previously
faulty device before it can be revived via 'hot_add_disk'.

Signed-off-by: Jonathan Brassow 
Signed-off-by: NeilBrown

DM RAID: Break-up untidy function

2013-06-13T22:10:25+00:00

DM RAID:  Break-up untidy function

Clean-up excessive indentation by moving some code in raid_resume()
into its own function.

Signed-off-by: Jonathan Brassow 
Signed-off-by: NeilBrown

DM RAID: Add ability to restore transiently failed devices on resume

2013-06-13T22:10:24+00:00

DM RAID: Add ability to restore transiently failed devices on resume

This patch adds code to the resume function to check over the devices
in the RAID array.  If any are found to be marked as failed and their
superblocks can be read, an attempt is made to reintegrate them into
the array.  This allows the user to refresh the array with a simple
suspend and resume of the array - rather than having to load a
completely new table, allocate and initialize all the structures and
throw away the old instantiation.

Signed-off-by: Jonathan Brassow 
Signed-off-by: NeilBrown

DM RAID: Add message/status support for changing sync action

2013-04-24T01:42:43+00:00

DM RAID:  Add message/status support for changing sync action

This patch adds a message interface to dm-raid to allow the user to more
finely control the sync actions being performed by the MD driver.  This
gives the user the ability to initiate "check" and "repair" (i.e. scrubbing).
Two additional fields have been appended to the status output to provide more
information about the type of sync action occurring and the results of those
actions, specifically:  and .  These new fields
will always be populated.  This is essentially the device-mapper way of doing
what MD controls through the 'sync_action' sysfs file and shows through the
'mismatch_cnt' sysfs file.

Signed-off-by: Jonathan Brassow 
Signed-off-by: NeilBrown

Merge tag 'md-3.9' of git://neil.brown.name/md

2013-03-06T01:22:08+00:00

Pull md updates from NeilBrown:
 "Mostly little bugfixes.

  Only "feature" is a new RAID10 layout which slightly improves the
  number of sets of devices that can concurrently fail, without data
  loss."

* tag 'md-3.9' of git://neil.brown.name/md:
  md: expedite metadata update when switching  read-auto -> active
  md: remove CONFIG_MULTICORE_RAID456
  md/raid1,raid10: fix deadlock with freeze_array()
  md/raid0: improve error message when converting RAID4-with-spares to RAID0
  md: raid0: fix error return from create_stripe_zones.
  md: fix two bugs when attempting to resize RAID0 array.
  DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms
  MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2)
  MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1)
  MD RAID10: Minor non-functional code changes
  md: raid1,10: Handle REQ_WRITE_SAME flag in write bios
  md: protect against crash upon fsync on ro array