Merge tag 'dm-3.14-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper fixes form Mike Snitzer:
 "Two small fixes for the DM cache target:

   - fix corruption with >2TB fast device due to truncation bug
   - fix access beyond end of origin device due to a partial block"

* tag 'dm-3.14-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache: fix access beyond end of origin device
  dm cache: fix truncation bug when copying a block to/from >2TB fast device

1 files changed, 5 insertions, 6 deletions

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 1af70145fab9..074b9c8e4cf0 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) {
@@ -2464,20 +2465,18 @@ static int cache_map(struct dm_target *ti, struct bio *bio)
         bool discarded_block;
         struct dm_bio_prison_cell *cell;
         struct policy_result lookup_result;
-        struct per_bio_data *pb;
+        struct per_bio_data *pb = init_per_bio_data(bio, pb_data_size);
 
-        if (from_oblock(block) > from_oblock(cache->origin_blocks)) {
+        if (unlikely(from_oblock(block) >= from_oblock(cache->origin_blocks))) {
                 /*
                  * This can only occur if the io goes to a partial block at
                  * the end of the origin device.  We don't cache these.
                  * Just remap to the origin and carry on.
                  */
-                remap_to_origin_clear_discard(cache, bio, block);
+                remap_to_origin(cache, bio);
                 return DM_MAPIO_REMAPPED;
         }
 
-        pb = init_per_bio_data(bio, pb_data_size);
-
         if (bio->bi_rw & (REQ_FLUSH | REQ_FUA | REQ_DISCARD)) {
                 defer_bio(cache, bio);
                 return DM_MAPIO_SUBMITTED;