Hello All,
When RAID6 is set up on dm-integrity target that detects massive
corruption, the leg will be ejected from the array. Even if the issue
is correctable with a sector re-write and the array has necessary
redundancy to correct it.
The leg is ejected because it runs up the rdev->read_errors beyond
conf->max_nr_stripes (600).
The return status in dm-crypt when there is a data integrity error is
BLK_STS_PROTECTION.
I propose we don't increment the read_errors when the bi->bi_status is
BLK_STS_PROTECTION.
drivers/md/raid5.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index b83bce2beb66..ca73e60e33ed 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2526,7 +2526,8 @@ static void raid5_end_read_request(struct bio * bi)
int set_bad = 0;
clear_bit(R5_UPTODATE, &sh->dev[i].flags);
- atomic_inc(&rdev->read_errors);
+ if (!(bi->bi_status == BLK_STS_PROTECTION))
+ atomic_inc(&rdev->read_errors);
if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
pr_warn_ratelimited(
"md/raid:%s: read error on replacement device (sector
%llu on %s).\n",
--
2.20.1
The script below creates the failing environment. It needs to run a
couple times in a row to take the leg out.
#!/bin/sh -x
#### cleanup script:
mdadm --stop /dev/md/robust
for i in $(seq $COUNT); do
integritysetup close integr-$i
rm -Rf raw-$i
done
### configurable RAID level:
SIZE=$((1024*1024*1024))
COUNT=4
LEVEL=6
for i in $(seq $COUNT); do
truncate -s $SIZE "raw-$i"
integritysetup format --integrity sha1 --tag-size 16 \
--sector-size 4096 --batch-mode "./raw-$i"
integritysetup open --integrity-no-journal --integrity \
sha1 --batch-mode "./raw-$i" "integr-$i"
dd if=/dev/zero "of=/dev/mapper/integr-$i" bs=$((4096*512)) || :
done
mdadm --create /dev/md/robust -n$COUNT --level=$LEVEL \
$(seq --format "/dev/mapper/integr-%.0f" $COUNT)
mdadm --wait /dev/md/robust && echo ready
mdadm --stop /dev/md/robust
integritysetup close integr-1
sync
tr '\000' '\377' < /dev/zero | dd of=raw-1 bs=4096 \
seek=$((SIZE/4096/2)) count=$((SIZE/4096/2-256)) \
conv=notrunc status=progress
sync
echo 3 > /proc/sys/vm/drop_caches
integritysetup open --integrity-no-journal --integrity \
sha1 "./raw-1" "integr-1"
# udev is a bit too eager to start assembling the array, so stop the
partially assembled one
mdadm --stop /dev/$(grep -oE '(md[^ ]*).*inactive' /proc/mdstat | awk
'{print $1}')
mdadm --assemble /dev/md/robust $(seq --format \
"/dev/mapper/integr-%.0f" $COUNT)
mdadm --action=repair /dev/md/robust
mdadm --wait /dev/md/robust && echo ready
