The patch titled
md: fix newly introduced read-corruption with raid6
has been added to the -mm tree. Its filename is
md-fix-newly-introduced-read-corruption-with-raid6.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: md: fix newly introduced read-corruption with raid6
From: NeilBrown <neilb@xxxxxxx>
chunk_aligned_read and retry_aligned_read assume that
data_disks == raid_disks - 1
which is not true for raid6.
So when an aligned read request bypasses the cache, we can get the wrong data.
Also change the calculate of raid_disks in compute_blocknr to make it more
obviously correct.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/md/raid5.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff -puN drivers/md/raid5.c~md-fix-newly-introduced-read-corruption-with-raid6 drivers/md/raid5.c
--- a/drivers/md/raid5.c~md-fix-newly-introduced-read-corruption-with-raid6
+++ a/drivers/md/raid5.c
@@ -823,7 +823,8 @@ static sector_t raid5_compute_sector(sec
static sector_t compute_blocknr(struct stripe_head *sh, int i)
{
raid5_conf_t *conf = sh->raid_conf;
- int raid_disks = sh->disks, data_disks = raid_disks - 1;
+ int raid_disks = sh->disks;
+ int data_disks = raid_disks - conf->max_degraded;
sector_t new_sector = sh->sector, check;
int sectors_per_chunk = conf->chunk_size >> 9;
sector_t stripe;
@@ -859,7 +860,6 @@ static sector_t compute_blocknr(struct s
}
break;
case 6:
- data_disks = raid_disks - 2;
if (i == raid6_next_disk(sh->pd_idx, raid_disks))
return 0; /* It is the Q disk */
switch (conf->algorithm) {
@@ -2725,7 +2725,7 @@ static int chunk_aligned_read(request_qu
mddev_t *mddev = q->queuedata;
raid5_conf_t *conf = mddev_to_conf(mddev);
const unsigned int raid_disks = conf->raid_disks;
- const unsigned int data_disks = raid_disks - 1;
+ const unsigned int data_disks = raid_disks - conf->max_degraded;
unsigned int dd_idx, pd_idx;
struct bio* align_bi;
mdk_rdev_t *rdev;
@@ -3145,7 +3145,7 @@ static int retry_aligned_read(raid5_con
logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
sector = raid5_compute_sector( logical_sector,
conf->raid_disks,
- conf->raid_disks-1,
+ conf->raid_disks - conf->max_degraded,
&dd_idx,
&pd_idx,
conf);
_
Patches currently in -mm which might be from neilb@xxxxxxx are
origin.patch
auth_gss-unregister-gss_domain-when-unloading-module-fix.patch
fix-sunrpc-wakeup-execute-race-condition.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets-tidy.patch
remove-lock_key-approach-to-managing-nested-bd_mutex-locks.patch
simplify-some-aspects-of-bd_mutex-nesting.patch
use-mutex_lock_nested-for-bd_mutex-to-avoid-lockdep-warning.patch
avoid-lockdep-warning-in-md.patch
bdev-fix-bd_part_count-leak.patch
lockdep-annotate-nfsd4-recover-code.patch
md-tidy-up-device-change-notification-when-an-md-array-is-stopped.patch
md-define-raid5_mergeable_bvec.patch
md-handle-bypassing-the-read-cache-assuming-nothing-fails.patch
md-allow-reads-that-have-bypassed-the-cache-to-be-retried-on-failure.patch
md-allow-reads-that-have-bypassed-the-cache-to-be-retried-on-failure-fix.patch
md-enable-bypassing-cache-for-reads.patch
md-fix-innocuous-bug-in-raid6-stripe_to_pdidx.patch
md-fix-newly-introduced-read-corruption-with-raid6.patch
md-misc-fixes-for-aligned-read-handling.patch
md-fix-a-couple-more-bugs-in-raid5-6-aligned-reads.patch
md-conditionalize-some-code.patch
md-change-lifetime-rules-for-md-devices.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
-
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