3.11.10.7 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Heinz Mauelshagen <[email protected]> commit 8b9d96666529a979acf4825391efcc7c8a3e9f12 upstream. 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 <[email protected]> Acked-by: Joe Thornber <[email protected]> Signed-off-by: Mike Snitzer <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- drivers/md/dm-cache-target.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index d8dbc2f..e36beca 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -865,12 +865,13 @@ 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) { -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
