md/raid5: avoid an extra write when writing to a known-bad-block.

If we write to a known-bad-block it will be flags as having
a ReadError by analyse_stripe, but the write will proceed anyway
(as it should).  Then the read-error handling will kick in an
write again, then re-read.

We don't need that 'write-again', so set R5_ReWrite so it looks like
it has already been done.  Then we will just get the re-read, which we
want.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2013-04-24 11:42:42 +10:00
parent 6f608040ce
commit c0b32972fb

View File

@ -1887,8 +1887,15 @@ static void raid5_end_write_request(struct bio *bi, int error)
&rdev->mddev->recovery);
} else if (is_badblock(rdev, sh->sector,
STRIPE_SECTORS,
&first_bad, &bad_sectors))
&first_bad, &bad_sectors)) {
set_bit(R5_MadeGood, &sh->dev[i].flags);
if (test_bit(R5_ReadError, &sh->dev[i].flags))
/* That was a successful write so make
* sure it looks like we already did
* a re-write.
*/
set_bit(R5_ReWrite, &sh->dev[i].flags);
}
}
rdev_dec_pending(rdev, conf->mddev);