[PATCH 03/54] debugfs: Optionally ignore bad checksums

["Darrick J. Wong" <djwong@us.ibm.com>]

If someone is debugging a badly damaged filesystem, it might be useful to
disable the checksum verifications that will otherwise prevent the filesystem
from loading.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
 debugfs/debugfs.8.in |    7 ++++++-
 debugfs/debugfs.c    |    7 +++++--
 2 files changed, 11 insertions(+), 3 deletions(-)


diff --git a/debugfs/debugfs.8.in b/debugfs/debugfs.8.in
index 08d9068..157c667 100644
--- a/debugfs/debugfs.8.in
+++ b/debugfs/debugfs.8.in
@@ -8,7 +8,7 @@ debugfs \- ext2/ext3/ext4 file system debugger
 .SH SYNOPSIS
 .B debugfs
 [
-.B \-DVwci
+.B \-DVwcin
 ]
 [
 .B \-b
@@ -48,6 +48,11 @@ file system (e.g /dev/hdXX).
 Specifies that the file system should be opened in read-write mode.
 Without this option, the file system is opened in read-only mode.
 .TP
+.I \-n
+Disables metadata checksum verification.  This should only be used if
+you believe the metadata to be correct despite the complaints of
+e2fsprogs.
+.TP
 .I \-c
 Specifies that the file system should be opened in catastrophic mode, in
 which the inode and group bitmaps are not read initially.  This can be
diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index 04d5139..4ff23ef 100644
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -2271,9 +2271,9 @@ int main(int argc, char **argv)
 	int		catastrophic = 0;
 	char		*data_filename = 0;
 #ifdef READ_ONLY
-	const char	*opt_string = "icR:f:b:s:Vd:D";
+	const char	*opt_string = "nicR:f:b:s:Vd:D";
 #else
-	const char	*opt_string = "iwcR:f:b:s:Vd:D";
+	const char	*opt_string = "niwcR:f:b:s:Vd:D";
 #endif
 
 	if (debug_prog_name == 0)
@@ -2300,6 +2300,9 @@ int main(int argc, char **argv)
 		case 'i':
 			open_flags |= EXT2_FLAG_IMAGE_FILE;
 			break;
+		case 'n':
+			open_flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
+			break;
 #ifndef READ_ONLY
 		case 'w':
 			open_flags |= EXT2_FLAG_RW;