[PATCH 1/2] metadump: Fill attribute values with 'v' rather than NUL

[Eric Sandeen]

Rather than memset attribute values to '\0', use the character 'v' -
otherwise in some cases we get attributes with a non-zero value
length which start with a NUL, and that makes some userspace tools
unhappy, yielding results like this:

security.oO^Lio.=0sAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=

Signed-off-by: Eric Sandeen <sandeen at redhat.com>
---

diff --git a/db/metadump.c b/db/metadump.c
index 2286b71..a30f90e 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -1083,8 +1083,8 @@ obfuscate_sf_attr(
 	xfs_dinode_t		*dip)
 {
 	/*
-	 * with extended attributes, obfuscate the names and zero the actual
-	 * values.
+	 * with extended attributes, obfuscate the names and fill the actual
+	 * values with 'v' (to see a valid string length, as opposed to NULLs)
 	 */
 
 	xfs_attr_shortform_t	*asfp;
@@ -1124,7 +1124,7 @@ obfuscate_sf_attr(
 		}
 
 		generate_obfuscated_name(0, asfep->namelen, &asfep->nameval[0]);
-		memset(&asfep->nameval[asfep->namelen], 0, asfep->valuelen);
+		memset(&asfep->nameval[asfep->namelen], 'v', asfep->valuelen);
 
 		asfep = (xfs_attr_sf_entry_t *)((char *)asfep +
 				XFS_ATTR_SF_ENTSIZE(asfep));
@@ -1302,7 +1302,7 @@ obfuscate_attr_block(
 				/* magic to handle attr and attr3 */
 				memset(block +
 					(bs - XFS_ATTR3_RMT_BUF_SPACE(mp, bs)),
-				      0, XFS_ATTR3_RMT_BUF_SPACE(mp, bs));
+				      'v', XFS_ATTR3_RMT_BUF_SPACE(mp, bs));
 		}
 		return;
 	}
@@ -1339,7 +1339,7 @@ obfuscate_attr_block(
 			}
 			generate_obfuscated_name(0, local->namelen,
 				&local->nameval[0]);
-			memset(&local->nameval[local->namelen], 0,
+			memset(&local->nameval[local->namelen], 'v',
 				be16_to_cpu(local->valuelen));
 		} else {
 			remote = xfs_attr3_leaf_name_remote(leaf, i);