linux-stable.git/drivers/md/raid5.c, branch linux-2.6.36.y

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/raid5: export raid5 unplugging interface.

2010-07-26T02:53:10+00:00

Also remove remaining accesses to ->queue and ->gendisk when ->queue
is NULL (As it is in a DM target).

Signed-off-by: NeilBrown

md/plug: optionally use plugger to unplug an array during resync/recovery.

2010-07-26T02:53:08+00:00

If an array doesn't have a 'queue' then md_do_sync cannot
unplug it.
In that case it will have a 'plugger', so make that available
to the mddev, and use it to unplug the array if needed.

Signed-off-by: NeilBrown

md/raid5: add simple plugging infrastructure.

2010-07-26T02:53:08+00:00

md/raid5 uses the plugging infrastructure provided by the block layer
and 'struct request_queue'.  However when we plug raid5 under dm there
is no request queue so we cannot use that.

So create a similar infrastructure that is much lighter weight and use
it for raid5.

Signed-off-by: NeilBrown

md/raid5: export is_congested test

2010-07-26T02:52:29+00:00

the dm module will need this for dm-raid45.

Also only access ->queue->backing_dev_info->congested_fn
if ->queue actually exists.  It won't in a dm target.

Signed-off-by: NeilBrown

raid5: Don't set read-ahead when there is no queue

2010-07-26T02:52:27+00:00

dm-raid456 does not provide a 'queue' for raid5 to use,
so we must make raid5 stop depending on the queue.

First: read_ahead
dm handles read-ahead adjustment fully in userspace, so
simply don't do any readahead adjustments if there is
no queue.

Also re-arrange code slightly so all the accesses to ->queue are
together.

Finally, move the blk_queue_merge_bvec function into the 'if' as
the ->split_io setting in dm-raid456 has the same effect.

Signed-off-by: NeilBrown

md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk

2010-07-26T02:52:26+00:00

We will shortly allow md devices with no gendisk (they are attached to
a dm-target instead).  That will cause mdname() to return 'mdX'.
There is one place where mdname really needs to be unique: when
creating the name for a slab cache.
So in that case, if there is no gendisk, you the address of the mddev
formatted in HEX to provide a unique name.

Signed-off-by: NeilBrown