md/raid1: perform bad-block tests for WriteMostly devices too.
We normally try to avoid reading from write-mostly devices, but when
we do we really have to check for bad blocks and be sure not to
try reading them.
With the current code, best_good_sectors might not get set and that
causes zero-length read requests to be send down which is very
confusing.
This bug was introduced in commit d2eb35acfd
and so the patch
is suitable for 3.1.x and 3.2.x
Reported-and-tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reported-and-tested-by: Art -kwaak- van Breemen <ard@telegraafnet.nl>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org
This commit is contained in:
parent
f2a371c5e7
commit
307729c8bc
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@ -531,8 +531,17 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
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if (test_bit(WriteMostly, &rdev->flags)) {
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if (test_bit(WriteMostly, &rdev->flags)) {
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/* Don't balance among write-mostly, just
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/* Don't balance among write-mostly, just
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* use the first as a last resort */
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* use the first as a last resort */
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if (best_disk < 0)
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if (best_disk < 0) {
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if (is_badblock(rdev, this_sector, sectors,
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&first_bad, &bad_sectors)) {
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if (first_bad < this_sector)
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/* Cannot use this */
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continue;
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best_good_sectors = first_bad - this_sector;
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} else
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best_good_sectors = sectors;
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best_disk = disk;
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best_disk = disk;
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}
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continue;
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continue;
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}
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}
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/* This is a reasonable device to use. It might
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/* This is a reasonable device to use. It might
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