Re: [PATCH 02/54] libext2fs: Change ext4 on-disk layout to support metadata checksumming
From: Ted Ts'o <tytso@mit.edu>
Date: 2012-03-09 22:04:47
On Tue, Mar 06, 2012 at 03:57:34PM -0800, Darrick J. Wong wrote:
Define flags and extend ext4 structure definitions to support metadata checksumming. Ted T'so covered many of these fields in an earlier patch, but there are more required changes to the disk layout. Signed-off-by: Darrick J. Wong <redacted>
quoted hunk ↗ jump to hunk
@@ -619,7 +630,7 @@ struct ext2_super_block { __u64 s_mmp_block; /* Block for multi-mount protection */ __u32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/ __u8 s_log_groups_per_flex; /* FLEX_BG group size */ - __u8 s_reserved_char_pad; + __u8 s_checksum_type; /* metadata checksum algorithm */ __u16 s_reserved_pad; /* Padding to next 32bits */ __u64 s_kbytes_written; /* nr of lifetime kilobytes written */ __u32 s_snapshot_inum; /* Inode number of active snapshot */
Note: when you change the superblock definition, you *must* also update the test in lib/ext2fs/tst_super_size.c. If you don't then running "make check" from the top-level of the build tree will likely bomb out. And you will also reveal to me that you haven't run the full set of regression tests before submitting your patch series. :-) - Ted