ext4: fix memory leakage in mext_check_coverage

Regression was introduced by following commit 8c854473
TESTCASE (git://oss.sgi.com/xfs/cmds/xfstests.git):
#while true;do ./check 301 || break ;done

Also fix potential memory leakage in get_ext_path() once
ext4_ext_find_extent() have failed.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index c1f15b2..bbae4ed 100644 (file)
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -32,16 +32,18 @@
  */
 static inline int
 get_ext_path(struct inode *inode, ext4_lblk_t lblock,
-               struct ext4_ext_path **path)
+               struct ext4_ext_path **orig_path)
 {
        int ret = 0;
+       struct ext4_ext_path *path;
 
-       *path = ext4_ext_find_extent(inode, lblock, *path);
-       if (IS_ERR(*path)) {
-               ret = PTR_ERR(*path);
-               *path = NULL;
-       } else if ((*path)[ext_depth(inode)].p_ext == NULL)
+       path = ext4_ext_find_extent(inode, lblock, *orig_path);
+       if (IS_ERR(path))
+               ret = PTR_ERR(path);
+       else if (path[ext_depth(inode)].p_ext == NULL)
                ret = -ENODATA;
+       else
+               *orig_path = path;
 
        return ret;
 }
@@ -611,24 +613,25 @@ mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count,
 {
        struct ext4_ext_path *path = NULL;
        struct ext4_extent *ext;
+       int ret = 0;
        ext4_lblk_t last = from + count;
        while (from < last) {
                *err = get_ext_path(inode, from, &path);
                if (*err)
-                       return 0;
+                       goto out;
                ext = path[ext_depth(inode)].p_ext;
-               if (!ext) {
-                       ext4_ext_drop_refs(path);
-                       return 0;
-               }
-               if (uninit != ext4_ext_is_uninitialized(ext)) {
-                       ext4_ext_drop_refs(path);
-                       return 0;
-               }
+               if (uninit != ext4_ext_is_uninitialized(ext))
+                       goto out;
                from += ext4_ext_get_actual_len(ext);
                ext4_ext_drop_refs(path);
        }
-       return 1;
+       ret = 1;
+out:
+       if (path) {
+               ext4_ext_drop_refs(path);
+               kfree(path);
+       }
+       return ret;
 }
 
 /**