udf: Use IS_ERR when loading metadata mirror file entry

Alden Tondettar · jankara · commit 3743a03e72b7 · 2016-05-19T12:00:03.000+02:00
Currently when udf_get_pblock_meta25() fails to map a block using the
primary metadata file, it will attempt to load the mirror file entry by
calling udf_find_metadata_inode_efe().  That function will return a ERR_PTR
if it fails, but the return value is only checked against NULL.  Test the
return value using IS_ERR() and change it to NULL if needed.

Signed-off-by: Alden Tondettar &lt;alden.tondettar@gmail.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
diff --git a/fs/udf/partition.c b/fs/udf/partition.c
@@ -326,6 +326,8 @@ uint32_t udf_get_pblock_meta25(struct super_block *sb, uint32_t block,
 		if (!(mdata->s_flags & MF_MIRROR_FE_LOADED)) {
 			mdata->s_mirror_fe = udf_find_metadata_inode_efe(sb,
 				mdata->s_mirror_file_loc, map->s_partition_num);
+			if (IS_ERR(mdata->s_mirror_fe))
+				mdata->s_mirror_fe = NULL;
 			mdata->s_flags |= MF_MIRROR_FE_LOADED;
 		}
 

Original file line number	Diff line number	Diff line change
`@@ -326,6 +326,8 @@ uint32_t udf_get_pblock_meta25(struct super_block *sb, uint32_t block,`
`326`	`326`	`if (!(mdata->s_flags & MF_MIRROR_FE_LOADED)) {`
`327`	`327`	`mdata->s_mirror_fe = udf_find_metadata_inode_efe(sb,`
`328`	`328`	`mdata->s_mirror_file_loc, map->s_partition_num);`
	`329`	`+ if (IS_ERR(mdata->s_mirror_fe))`
	`330`	`+ mdata->s_mirror_fe = NULL;`
`329`	`331`	`mdata->s_flags \|= MF_MIRROR_FE_LOADED;`
`330`	`332`	`}`
`331`	`333`