diff options
| author | Heinz Mauelshagen <heinzm@redhat.com> | 2014-03-12 03:40:05 +0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2014-03-12 21:49:27 +0400 |
| commit | 8b9d96666529a979acf4825391efcc7c8a3e9f12 (patch) | |
| tree | 142c3205b54a86c96cba376f1dd689463b1d6548 | |
| parent | cebc2de44d3bce53e46476e774126c298ca2c8a9 (diff) | |
| download | linux-8b9d96666529a979acf4825391efcc7c8a3e9f12.tar.xz | |
dm cache: fix truncation bug when copying a block to/from >2TB fast device
During demotion or promotion to a cache's >2TB fast device we must not
truncate the cache block's associated sector to 32bits. The 32bit
temporary result of from_cblock() caused a 32bit multiplication when
calculating the sector of the fast device in issue_copy_real().
Use an intermediate 64bit type to store the 32bit from_cblock() to allow
for proper 64bit multiplication.
Here is an example of how this bug manifests on an ext4 filesystem:
EXT4-fs error (device dm-0): ext4_mb_generate_buddy:756: group 17136, 32768 clusters in bitmap, 30688 in gd; block bitmap corrupt.
JBD2: Spotted dirty metadata buffer (dev = dm-0, blocknr = 0). There's a risk of filesystem corruption in case of system crash.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
| -rw-r--r-- | drivers/md/dm-cache-target.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 1af70145fab9..354bbc1b9a3c 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -979,12 +979,13 @@ static void issue_copy_real(struct dm_cache_migration *mg) int r; struct dm_io_region o_region, c_region; struct cache *cache = mg->cache; + sector_t cblock = from_cblock(mg->cblock); o_region.bdev = cache->origin_dev->bdev; o_region.count = cache->sectors_per_block; c_region.bdev = cache->cache_dev->bdev; - c_region.sector = from_cblock(mg->cblock) * cache->sectors_per_block; + c_region.sector = cblock * cache->sectors_per_block; c_region.count = cache->sectors_per_block; if (mg->writeback || mg->demote) { |