[PATCH] tune2fs: warn if the filesystem journal is dirty

[Andreas Dilger <adilger@dilger.ca>]

From: Jim Garlick <garlick@llnl.gov>

Running tune2fs on a filesystem with an unrecovered journal can
cause the tune2fs settings changes in the superblock to be reverted
when the journal is replayed if it contains an uncommitted copy of
the superblock.  Print a warning if this is detected so that the
user isn't surprised if it happens.

Signed-off-by: Jim Garlick <garlick@llnl.gov>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
---
 misc/tune2fs.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index cd1d17f..fcb963a 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -2397,6 +2397,7 @@ retry_open:
 		ext2fs_mark_super_dirty(fs);
 		printf(_("Setting stripe width to %d\n"), stripe_width);
 	}
+
 	if (ext_mount_opts) {
 		strncpy((char *)(fs->super->s_mount_opts), ext_mount_opts,
 			sizeof(fs->super->s_mount_opts));
@@ -2406,6 +2407,17 @@ retry_open:
 		       ext_mount_opts);
 		free(ext_mount_opts);
 	}
+
+	/* Warn if file system needs recovery and it is opened for writing. */
+	if ((open_flag & EXT2_FLAG_RW) && !(mount_flags & EXT2_MF_MOUNTED) &&
+	    (sb->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL) &&
+	    (sb->s_feature_incompat & EXT3_FEATURE_INCOMPAT_RECOVER)) {
+		fprintf(stderr,
+			_("Warning: needs_recovery flag is set. You may wish\n"
+			  "replay the journal then rerun this command, or any\n"
+			  "changes may be overwritten by journal recovery.\n"));
+	}
+
 	free(device_name);
 	remove_error_table(&et_ext2_error_table);
 
-- 
1.7.3.4