# tune2fs -O ^has_journal -f /dev/loop0 
The needs_recovery flag is set.  Please run e2fsck before clearing
the has_journal flag.
tune2fs 1.41.3 (12-Oct-2008)

# tune2fs -l /dev/loop0 
tune2fs 1.41.3 (12-Oct-2008)
Filesystem volume name:   <none>
Last mounted on:          <not available>
Filesystem UUID:          45ee3919-bce0-4395-bf2d-830675247591
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file
Filesystem flags:         signed_directory_hash 
Default mount options:    journal_data
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              32768
Block count:              131072
Reserved block count:     6553
Free blocks:              0
Free inodes:              12758
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      31
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Filesystem created:       Thu Apr  2 13:36:19 2009
Last mount time:          Thu Apr  2 22:28:14 2009
Last write time:          Thu Apr  2 22:28:14 2009
Mount count:              2
Maximum mount count:      25
Last checked:             Thu Apr  2 13:46:58 2009
Check interval:           15552000 (6 months)
Next check after:         Tue Sep 29 13:46:58 2009
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:	          256
Required extra isize:     28
Desired extra isize:      28
Journal UUID:             797b5e1e-edba-40d2-835c-2018ecb8c504
Journal device:	          0x0701
Default directory hash:   half_md4
Directory Hash Seed:      884b5714-f786-48ab-88f9-a0cea4ef871c
Journal backup:           inode blocks