[PATCH] xfs_metadump: obfuscate remote symlinks on CRC filesystems

[Eric Sandeen]

On CRC filesystems, the symlink block starts with a header,
which contains magic, "XLSM"

The code happens to "work" today w/o corrupting anything,
because it seems "XSLM" as a string, decides it's too short
to obfuscate, and leaves it alone.

But the real symlink target is untouched.  Fix that by moving
the pointer to the string we want to obfuscate by the size
of the header, and shorten the length to obfuscate accordingly.

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

diff --git a/db/metadump.c b/db/metadump.c
index a599571..80a41cd 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -1239,8 +1239,12 @@ static void
 obfuscate_symlink_block(
 	char			*block)
 {
-	/* XXX: need to handle CRC headers */
-	obfuscate_path_components(block, mp->m_sb.sb_blocksize);
+	if (xfs_sb_version_hascrc(&(mp)->m_sb))
+		block += sizeof(struct xfs_dsymlink_hdr);
+
+	obfuscate_path_components(block,
+				  XFS_SYMLINK_BUF_SPACE(mp,
+					mp->m_sb.sb_blocksize));
 }
 
 #define MAX_REMOTE_VALS		4095