kernel/linux.git/drivers/md/raid5.c, branch v3.4.55

md/raid5: fix calculate of 'degraded' when a replacement becomes active.

2012-10-02T17:29:55+00:00

commit e5c86471f933608db5d43679f84cb4346c32033e upstream. When a replacement device becomes active, we mark the device that it replaces as 'faulty' so that it can subsequently get removed. However 'calc_degraded' only pays attention to the primary device, not the replacement, so the array appears to become degraded, which is wrong. So teach 'calc_degraded' to consider any replacement if a primary device is faulty. This is suitable for -stable as an incorrect 'degraded' value can confuse md and could lead to data corruption. This is only relevant for 3.3 and later. Reported-by: Robin Hill Reported-by: John Drescher Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid5: Do not add data_offset before call to is_badblock

2012-07-16T16:04:43+00:00

commit 6c0544e255dd6582a9899572e120fb55d9f672a4 upstream. In chunk_aligned_read() we are adding data_offset before calling is_badblock. But is_badblock also adds data_offset, so that is bad. So move the addition of data_offset to after the call to is_badblock. This bug was introduced by commit 31c176ecdf3563140e639 md/raid5: avoid reading from known bad blocks. which first appeared in 3.0. So that patch is suitable for any -stable kernel from 3.0.y onwards. However it will need minor revision for most of those (as the comment didn't appear until recently). Signed-off-by: majianpeng Signed-off-by: NeilBrown [bwh: Backported to 3.2: ignored missing comment] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

raid5: delayed stripe fix

2012-07-16T16:04:41+00:00

commit fab363b5ff502d1b39ddcfec04271f5858d9f26e upstream. There isn't locking setting STRIPE_DELAYED and STRIPE_PREREAD_ACTIVE bits, but the two bits have relationship. A delayed stripe can be moved to hold list only when preread active stripe count is below IO_THRESHOLD. If a stripe has both the bits set, such stripe will be in delayed list and preread count not 0, which will make such stripe never leave delayed list. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid5: In ops_run_io, inc nr_pending before calling md_wait_for_blocked_rdev

2012-07-16T16:04:25+00:00

commit 1850753d2e6d9ca7856581ca5d3cf09521e6a5d7 upstream. In ops_run_io(), the call to md_wait_for_blocked_rdev will decrement nr_pending so we lose the reference we hold on the rdev. So atomic_inc it first to maintain the reference. This bug was introduced by commit 73e92e51b7969ef5477d md/raid5. Don't write to known bad block on doubtful devices. which appeared in 3.0, so patch is suitable for stable kernels since then. Signed-off-by: majianpeng Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid5: Fix a bug about judging if the operation is syncing or replacing

2012-04-03T05:37:38+00:00

When create a raid5 using assume-clean and echo check or repair to sync_action.Then component disks did not operated IO but the raid check/resync faster than normal. Because the judgement in function analyse_stripe(): if (do_recovery || sh->sector >= conf->mddev->recovery_cp) s->syncing = 1; else s->replacing = 1; When check or repair,the recovery_cp == MaxSectore,so syncing equal zero not one. This bug was introduced by commit 9a3e1101b827 md/raid5: detect and handle replacements during recovery. so this patch is suitable for 3.3-stable. Cc: stable@vger.kernel.org Signed-off-by: majianpeng Signed-off-by: NeilBrown

md/raid5: fix handling of bad blocks during recovery.

2012-04-03T05:36:17+00:00

1/ We can only treat a known-bad-block like a read-error if we have the data that belongs in that block. So fix that test. 2/ If we cannot recovery a stripe due to insufficient data, don't tell "md_done_sync" that the sync failed unless we really did fail something. If we successfully record bad blocks, that is success. Reported-by: "majianpeng" Signed-off-by: NeilBrown

md: tidy up rdev_for_each usage.

2012-03-19T01:46:39+00:00

md.h has an 'rdev_for_each()' macro for iterating the rdevs in an mddev. However it uses the 'safe' version of list_for_each_entry, and so requires the extra variable, but doesn't include 'safe' in the name, which is useful documentation. Consequently some places use this safe version without needing it, and many use an explicity list_for_each entry. So: - rename rdev_for_each to rdev_for_each_safe - create a new rdev_for_each which uses the plain list_for_each_entry, - use the 'safe' version only where needed, and convert all other list_for_each_entry calls to use rdev_for_each. Signed-off-by: NeilBrown

md: allow re-add to failed arrays.

2012-03-19T01:46:37+00:00

When an array is failed (some data inaccessible) then there is no point attempting to add a spare as it could not possibly be recovered. However that may be value in re-adding a recently removed device. e.g. if there is a write-intent-bitmap and it is clear, then access to the data could be restored by this action. So don't reject a re-add to a failed array for RAID10 and RAID5 (the only arrays types that check for a failed array). Signed-off-by: NeilBrown

md/raid5: use atomic_dec_return() instead of atomic_dec() and atomic_read().

2012-03-13T00:21:25+00:00

Signed-off-by: majianpeng Signed-off-by: NeilBrown

md/raid5: removed unused 'added_devices' variable.

2012-03-13T00:21:21+00:00

commit 908f4fbd265733 removed the last user of this variable, so we should discard it completely. Signed-off-by: NeilBrown