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author | NeilBrown | 2015-10-22 04:20:15 +0200 |
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committer | NeilBrown | 2015-10-24 07:24:25 +0200 |
commit | 8bce6d35b308d73cdb2ee273c95d711a55be688c (patch) | |
tree | 01b072a83736bae1455d7bb5743d271f91cd6325 /drivers/md/raid5.c | |
parent | md/raid10: don't clear bitmap bit when bad-block-list write fails. (diff) | |
download | kernel-qcow2-linux-8bce6d35b308d73cdb2ee273c95d711a55be688c.tar.gz kernel-qcow2-linux-8bce6d35b308d73cdb2ee273c95d711a55be688c.tar.xz kernel-qcow2-linux-8bce6d35b308d73cdb2ee273c95d711a55be688c.zip |
md/raid10: fix the 'new' raid10 layout to work correctly.
In Linux 3.9 we introduce a new 'far' layout for RAID10 which was
supposed to rotate the replicas differently and so provide better
resilience. In particular it could survive more combinations of 2
drive failures.
Unfortunately. due to a coding error, this some did what was wanted,
sometimes improved less than we hoped, and sometimes - in very
unlikely circumstances - put multiple replicas on the same device so
the redundancy was harmed.
No public user-space tool has created arrays using this layout so it
is very unlikely that zero-redundancy arrays actually exist. Probably
no arrays using any form of the new layout exist. But we cannot be
certain.
So use another bit in the 'layout' number and introduce a bug-fixed
version of the layout.
Also when assembling an array, if it has a zero-redundancy layout,
give a warning.
Reported-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Diffstat (limited to 'drivers/md/raid5.c')
0 files changed, 0 insertions, 0 deletions