linux-stable.git/drivers/md/raid10.c, branch linux-2.6.36.y

md: protect against NULL reference when waiting to start a raid10.

2011-01-07T21:58:33+00:00

commit 589a594be1fb8815b3f18e517be696c48664f728 upstream.

When we fail to start a raid10 for some reason, we call
md_unregister_thread to kill the thread that was created.

Unfortunately md_thread() will then make one call into the handler
(raid10d) even though md_wakeup_thread has not been called.  This is
not safe and as md_unregister_thread is called after mddev->private
has been set to NULL, it will definitely cause a NULL dereference.

So fix this at both ends:
 - md_thread should only call the handler if THREAD_WAKEUP has been
   set.
 - raid10 should call md_unregister_thread before setting things
   to NULL just like all the other raid modules do.

This is applicable to 2.6.35 and later.

Reported-by: "Citizen" 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

md raid-1/10 Fix bio_rw bit manipulations again

2010-08-18T06:16:05+00:00

commit 7b6d91daee5cac6402186ff224c3af39d79f4a0e changed the behaviour
of a few variables in raid1 and raid10 from flags to bit-sets, but
left them as type 'bool' so they did not work.

Change them (back) to unsigned long.
(historical note: see 1ef04fefe2241087d9db7e9615c3f11b516e36cf)

Signed-off-by: NeilBrown 
Reported-by: Jiri Slaby  and many others

md: provide appropriate return value for spare_active functions.

2010-08-18T02:04:32+00:00

md_check_recovery expects ->spare_active to return 'true' if any
spares were activated, but none of them do, so the consequent change
in 'degraded' is not notified through sysfs.

So count the number of spares activated, subtract it from 'degraded'
just once, and return it.

Reported-by: Adrian Drzewiecki 
Signed-off-by: NeilBrown

md: Notify sysfs when RAID1/5/10 disk is In_sync.

2010-08-18T01:49:02+00:00

When RAID1 is done syncing disks, it'll update the state
of synced rdevs to In_sync. But it neglected to notify
sysfs that the attribute changed. So any programs that
are waiting for an rdev's state to change will not be
woken.

(raid5/raid10 added by neilb)

Signed-off-by: Adrian Drzewiecki 
Signed-off-by: NeilBrown

Merge branch 'for-linus' of git://neil.brown.name/md

2010-08-10T22:38:19+00:00

* 'for-linus' of git://neil.brown.name/md: (24 commits)
  md: clean up do_md_stop
  md: fix another deadlock with removing sysfs attributes.
  md: move revalidate_disk() back outside open_mutex
  md/raid10: fix deadlock with unaligned read during resync
  md/bitmap:  separate out loading a bitmap from initialising the structures.
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.
  md/bitmap: optimise scanning of empty bitmaps.
  md/bitmap: clean up plugging calls.
  md/bitmap: reduce dependence on sysfs.
  md/bitmap: white space clean up and similar.
  md/raid5: export raid5 unplugging interface.
  md/plug: optionally use plugger to unplug an array during resync/recovery.
  md/raid5: add simple plugging infrastructure.
  md/raid5: export is_congested test
  raid5: Don't set read-ahead when there is no queue
  md: add support for raising dm events.
  md: export various start/stop interfaces
  md: split out md_rdev_init
  md: be more careful setting MD_CHANGE_CLEAN
  md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk
  ...

block: unify flags for struct bio and struct request

2010-08-07T16:20:39+00:00

Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

md/raid10: fix deadlock with unaligned read during resync

2010-08-07T11:17:00+00:00

If the 'bio_split' path in raid10-read is used while
resync/recovery is happening it is possible to deadlock.
Fix this be elevating ->nr_waiting for the duration of both
parts of the split request.

This fixes a bug that has been present since 2.6.22
but has only started manifesting recently for unknown reasons.
It is suitable for and -stable since then.

Reported-by:  Justin Bronder 
Tested-by:  Justin Bronder 
Signed-off-by: NeilBrown 
Cc: stable@kernel.org

md: fix raid10 takeover: use new_layout for setup_conf

2010-06-24T03:33:51+00:00

Use mddev->new_layout in setup_conf.
Also use new_chunk, and don't set ->degraded in takeover().  That
gets set in run()

Signed-off-by: Maciej Trela 
Signed-off-by: NeilBrown

md: fix handling of array level takeover that re-arranges devices.

2010-06-24T03:33:24+00:00

Most array level changes leave the list of devices largely unchanged,
possibly causing one at the end to become redundant.
However conversions between RAID0 and RAID10 need to renumber
all devices (except 0).

This renumbering is currently being done in the ->run method when the
new personality takes over.  However this is too late as the common
code in md.c might already have invalidated some of the devices if
they had a ->raid_disk number that appeared to high.

Moving it into the ->takeover method is too early as the array is
still active at that time and wrong ->raid_disk numbers could cause
confusion.

So add a ->new_raid_disk field to mdk_rdev_s and use it to communicate
the new raid_disk number.
Now the common code knows exactly which devices need to be renumbered,
and which can be invalidated, and can do it all at a convenient time
when the array is suspend.
It can also update some symlinks in sysfs which previously were not be
updated correctly.

Reported-by: Maciej Trela 
Signed-off-by: NeilBrown

md: raid10: Fix null pointer dereference in fix_read_error()

2010-06-24T03:31:03+00:00

Such NULL pointer dereference can occur when the driver was fixing the
read errors/bad blocks and the disk was physically removed
causing a system crash. This patch check if the
rcu_dereference() returns valid rdev before accessing it in fix_read_error().

Cc: stable@kernel.org
Signed-off-by: Prasanna S. Panchamukhi 
Signed-off-by: Rob Becker 
Signed-off-by: NeilBrown