When performing a "recovery" or "check" pass on a RAID1 array, we read
from each device and possible, if there is a difference or a read error,
write back to some devices.
We use the same 'bio' for both read and write, resetting various fields
between the two operations.
We forgot to reset bv_offset and bv_len however. These are often left
unchanged, but in the case where there is an IO error one or two sectors
into a page, they are changed.
This results in correctable errors not being corrected properly. It does
not result in any data corruption.
Cc: "Fairbanks, David" <David.Fairbanks@stratus.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
698b18c1e8