linux/drivers/md, branch v2.6.32

md: revert incorrect fix for read error handling in raid1.

2009-12-01T06:30:59Z

commit 4706b349f was a forward port of a fix that was needed for SLES10. But in fact it is not needed in mainline because the earlier commit dd00a99e7a fixes the same problem in a better way. Further, this commit introduces a bug in the way it interacts with the automatic read-error-correction. If, after a read error is successfully corrected, the same disk is chosen to re-read - the re-read won't be attempted but an error will be returned instead. After reverting that commit, there is the possibility that a read error on a read-only array (where read errors cannot be corrected as that requires a write) will repeatedly read the same device and continue to get an error. So in the "Array is readonly" case, fail the drive immediately on a read error. Signed-off-by: NeilBrown Cc: stable@kernel.org

md/raid5: Allow dirty-degraded arrays to be assembled when only party is degraded.

2009-11-13T06:47:00Z

Normally is it not safe to allow a raid5 that is both dirty and degraded to be assembled without explicit request from that admin, as it can cause hidden data corruption. This is because 'dirty' means that the parity cannot be trusted, and 'degraded' means that the parity needs to be used. However, if the device that is missing contains only parity, then there is no issue and assembly can continue. This particularly applies when a RAID5 is being converted to a RAID6 and there is an unclean shutdown while the conversion is happening. So check for whether the degraded space only contains parity, and in that case, allow the assembly. Signed-off-by: NeilBrown

Don't unconditionally set in_sync on newly added device in raid5_reshape

2009-11-13T06:40:51Z

When a reshape finds that it can add spare devices into the array, those devices might already be 'in_sync' if they are beyond the old size of the array, or they might not if they are within the array. The first case happens when we change an N-drive RAID5 to an N+1-drive RAID5. The second happens when we convert an N-drive RAID5 to an N+1-drive RAID6. So set the flag more carefully. Also, ->recovery_offset is only meaningful when the flag is clear, so only set it in that case. This change needs the preceding two to ensure that the non-in_sync device doesn't get evicted from the array when it is stopped, in the case where v0.90 metadata is used. Signed-off-by: NeilBrown

md: allow v0.91 metadata to record devices as being active but not in-sync.

2009-11-13T06:40:48Z

This is a combination that didn't really make sense before. However when a reshape is converting e.g. raid5 -> raid6, the extra device is not fully in-sync, but is certainly active and contains important data. So allow that start to be meaningful and in particular get the 'recovery_offset' value (which is needed for any non-in-sync active device) from the reshape_position. Signed-off-by: NeilBrown

md: factor out updating of 'recovery_offset'.

2009-11-12T01:08:04Z

Each device has its own 'recovery_offset' showing how far recovery has progressed on the device. As the only real significance of this is that fact that it can be stored in the metadata and recovered at restart, and as only 1.x metadata can do this, we were only updating 'recovery_offset' to 'curr_resync_completed' when updating v1.x metadata. But this is wrong, and we will shortly make limited use of this field in v0.90 metadata. So move the update into common code. Signed-off-by: NeilBrown

md/raid5: make sure curr_sync_completes is uptodate when reshape starts

2009-11-06T03:59:29Z

This value is visible through sysfs and is used by mdadm when it manages a reshape (backing up data that is about to be rearranged). So it is important that it is always correct. Current it does not get updated properly when a reshape starts which can cause problems when assembling an array that is in the middle of being reshaped. This is suitable for 2.6.31.y stable kernels. Cc: stable@kernel.org Signed-off-by: NeilBrown

md: don't clear endpoint for resync when resync is interrupted.

2009-11-06T03:59:27Z

If a 'sync_max' has been set (via sysfs), it is wrong to clear it until a resync (or reshape or recovery ...) actually reached that point. So if a resync is interrupted (e.g. by device failure), leave 'resync_max' unchanged. This is particularly important for 'reshape' operations that do not change the size of the array. For such operations mdadm needs to monitor the reshape taking rolling backups of the section being reshaped. If resync_max gets cleared, the reshape can get ahead of mdadm and then the backups that mdadm creates are useless. This is suitable for 2.6.31.y stable kernels. Cc: stable@kernel.org Signed-off-by: NeilBrown

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

2009-10-31T19:12:19Z

* 'for-linus' of git://neil.brown.name/md: async_tx: fix asynchronous raid6 recovery for ddf layouts async_pq: rename scribble page async_pq: kill a stray dma_map() call and other cleanups md/raid6: kill a gcc-4.0.1 'uninitialized variable' warning raid6/async_tx: handle holes in block list in async_syndrome_val md/async: don't pass a memory pointer as a page pointer. md: Fix handling of raid5 array which is being reshaped to fewer devices. md: fix problems with RAID6 calculations for DDF. md/raid456: downlevel multicore operations to raid_run_ops md: drivers/md/unroll.pl replaced with awk analog md: remove clumsy usage of do_sync_mapping_range from bitmap code md: raid1/raid10: handle allocation errors during array setup. md/raid5: initialize conf->device_lock earlier md/raid1/raid10: add a cond_resched Revert "md: do not progress the resync process if the stripe was blocked"

md/raid6: kill a gcc-4.0.1 'uninitialized variable' warning

2009-10-20T01:09:41Z

Signed-off-by: Dan Williams

dm snapshot: allow chunk size to be less than page size

2009-10-16T22:18:22Z

Allow the snapshot chunk size to be smaller than the page size The code is now capable of handling this due to some previous fixes and enhancements. As the page size varies between computers, prior to this patch, the chunk size of a snapshot dictated which machines could read it: Snapshots created on one machine might not be readable on another. Signed-off-by: Mikulas Patocka Reviewed-by: Mike Snitzer Reviewed-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon