[PATCH 07/22] ext4: Create bitmap checksum helper functions
From: Darrick J. Wong <hidden>
Date: 2011-11-28 23:27:03
Also in:
linux-fsdevel, lkml
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
These helper functions will be used to calculate and verify the block and inode bitmap checksums. Signed-off-by: Darrick J. Wong <redacted> --- fs/ext4/bitmap.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/fs/ext4/bitmap.c b/fs/ext4/bitmap.c
index fa3af81..285d23a 100644
--- a/fs/ext4/bitmap.c
+++ b/fs/ext4/bitmap.c@@ -29,3 +29,16 @@ unsigned int ext4_count_free(struct buffer_head *map, unsigned int numchars) #endif /* EXT4FS_DEBUG */ +static __u32 ext4_bitmap_csum(struct super_block *sb, ext4_group_t group, + struct buffer_head *bh, int sz) +{ + __u32 csum; + struct ext4_sb_info *sbi = EXT4_SB(sb); + + group = cpu_to_le32(group); + csum = ext4_chksum(sbi, sbi->s_uuid_csum, (__u8 *)&group, + sizeof(group)); + csum = ext4_chksum(sbi, csum, (__u8 *)bh->b_data, sz); + + return csum; +}