ext4: support read-only images

Add a rocompat feature, "readonly" to mark a FS image as read-only.
The feature prevents the kernel and e2fsprogs from changing the image;
the flag can be toggled by tune2fs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Darrick J. Wong
2015-02-12 22:31:21 -05:00
committed by Theodore Ts'o
parent 04ecddb73d
commit 2cb5cc8b09
2 changed files with 10 additions and 1 deletions

View File

@@ -1530,6 +1530,7 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
* GDT_CSUM bits are mutually exclusive.
*/
#define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM 0x0400
#define EXT4_FEATURE_RO_COMPAT_READONLY 0x1000
#define EXT4_FEATURE_INCOMPAT_COMPRESSION 0x0001
#define EXT4_FEATURE_INCOMPAT_FILETYPE 0x0002