metadump: update manpage for dirty log/obfuscation issue

This is something that should be documented, as it is not obvious to
everyone.

Signed-off-by: Jan Tulak <jtulak@redhat.com>
[sandeen@redhat.com: edit for clarity]
[darrick.wong@oracle.com: edit for more clarity]
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/man/man8/xfs_metadump.8 b/man/man8/xfs_metadump.8
index 3731d6a367b841e898e66900dca4c08907304df4..81748816df369bc5f8772e2959fb4cf80af34d37 100644 (file)
--- a/man/man8/xfs_metadump.8
+++ b/man/man8/xfs_metadump.8
@@ -60,6 +60,22 @@ are not obfuscated. Names between 5 and 8 characters in length inclusively
 are partially obfuscated.
 .PP
 .B xfs_metadump
+cannot obfuscate metadata in the filesystem log.  Log
+recovery of an obfuscated metadump image may expose clear-text
+metadata and/or cause filesystem corruption in the restored image.
+It is recommended that the source filesystem first be mounted and
+unmounted, if possible, to ensure that the log is clean.
+A subsequent invocation of
+.B xfs_metadump
+will capture a clean log and obfuscate all metadata correctly.
+.PP
+If a metadump must be produced from a filesystem with a dirty log,
+it is recommended that obfuscation be turned off with -o option, if
+metadata such as filenames is not considered sensitive.  If obfuscation
+is required on a metadump with a dirty log, please inform the recipient
+of the metadump image about this situation.
+.PP
+.B xfs_metadump
 should not be used for any purposes other than for debugging and reporting
 filesystem problems. The most common usage scenario for this tool is when
 .BR xfs_repair (8)