Hi,
We have a report of a system oops during pvmove.
What appears to be happening is core_in_sync is being passed
a 'region' is which much too large. When this is indexed into the
bitset at lc->sync_bits it hits an unmapped page, and results in an
oops.
I believe the problem is in bio_to_region. See the patch below.
If a section of an lv which is *not* at the start of the lv is being
moved using dm-raid1, I think the region number is being calculated
wrongly resulting in the inappropriately large index. We really
need to subtract ti->begin from bi_sector before shifting.
We will try to get this patch tested on the machine that showed the
fault, but I would appreciate any feedback about the patch and I am
still not very familiar with this code.
Thanks,
NeilBrown
Signed-off-by: Neil Brown <neilb@xxxxxxx>
### Diffstat output
./drivers/md/dm-raid1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff ./drivers/md/dm-raid1.c~current~ ./drivers/md/dm-raid1.c
--- ./drivers/md/dm-raid1.c~current~ 2006-05-09 14:47:35.000000000 +1000
+++ ./drivers/md/dm-raid1.c 2006-05-09 14:47:35.000000000 +1000
@@ -111,7 +111,7 @@ struct region {
*/
static inline region_t bio_to_region(struct region_hash *rh, struct bio *bio)
{
- return bio->bi_sector >> rh->region_shift;
+ return (bio->bi_sector - rh->ms->ti->begin) >> rh->region_shift;
}
static inline sector_t region_to_sector(struct region_hash *rh, region_t region)
--
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
