ext4: fix wrong assert in ext4_mb_normalize_request()

maurizio-lombardi · tytso · commit b5b60778558c · 2014-05-27T12:48:56.000-04:00
The variable "size" is expressed as number of blocks and not as
number of clusters, this could trigger a kernel panic when using
ext4 with the size of a cluster different from the size of a block.

Cc: stable@vger.kernel.org
Signed-off-by: Maurizio Lombardi &lt;mlombard@redhat.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
@@ -3145,7 +3145,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
 	}
 	BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&
 			start > ac->ac_o_ex.fe_logical);
-	BUG_ON(size <= 0 || size > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
+	BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
 
 	/* now prepare goal request */
 

Original file line number	Diff line number	Diff line change
`@@ -3145,7 +3145,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,`
`3145`	`3145`	`}`
`3146`	`3146`	`BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&`
`3147`	`3147`	`start > ac->ac_o_ex.fe_logical);`
`3148`		`- BUG_ON(size <= 0 \|\| size > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));`
	`3148`	`+ BUG_ON(size <= 0 \|\| size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));`
`3149`	`3149`
`3150`	`3150`	`/* now prepare goal request */`
`3151`	`3151`