ext4: calculate and verify checksums of directory leaf blocks

Calculate and verify the checksums for directory leaf blocks
(i.e. blocks that only contain actual directory entries).  The
checksum lives in what looks to be an unused directory entry with a 0
name_len at the end of the block.  This scheme is not used for
internal htree nodes because the mechanism in place there only costs
one dx_entry, whereas the "empty" directory entry would cost two
dx_entries.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Darrick J. Wong
2012-04-29 18:41:10 -04:00
committed by Theodore Ts'o
parent dbe8944404
commit b0336e8d21
3 changed files with 259 additions and 15 deletions
+2
View File
@@ -2019,6 +2019,8 @@ extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
extern int ext4_ext_migrate(struct inode *);
/* namei.c */
extern int ext4_dirent_csum_verify(struct inode *inode,
struct ext4_dir_entry *dirent);
extern int ext4_orphan_add(handle_t *, struct inode *);
extern int ext4_orphan_del(handle_t *, struct inode *);
extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,