dm space map common: fix division bug in sm_ll_find_free_block()

This division bug meant the search for free metadata space could skip the final allocation bitmap's worth of entries. Fix affects DM thinp, cache and era targets. Cc: [email protected] Signed-off-by: Joe Thornber <[email protected]> Tested-by: Ming-Hung Tsai <[email protected]> Signed-off-by: Mike Snitzer <[email protected]>
mcd500 · Apr 19, 2021 · 5208692 · 5208692
1 parent a88b235
commit 5208692
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
@@ -339,6 +339,8 @@ int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 	 */
 	begin = do_div(index_begin, ll->entries_per_block);
 	end = do_div(end, ll->entries_per_block);
+	if (end == 0)
+		end = ll->entries_per_block;
 
 	for (i = index_begin; i < index_end; i++, begin = 0) {
 		struct dm_block *blk;