On Thu, Sep 15, 2011 at 1:06 PM, Andreas Dilger <adilger.kernel@xxxxxxxxx> wrote: > On 2011-09-15, at 12:50 AM, Amir Goldstein wrote: >> Here is a patch to reserve the exclude bitmap field, so we won't >> forget them again... >> The full patch series for adding exclude bitmap can be found here: >> https://github.com/amir73il/e2fsprogs-snapshots-patch-queue >> >> --- >> From: Amir Goldstein <amir73il@xxxxxxxxxxxx> >> Date: Thu, 15 Sep 2011 09:42:38 +0300 >> >> Ext4 snapshots require the compatible feature 'exclude_bitmap', meaning that >> the exclude bitmap was allocated. >> The allocated exclude bitmap blocks are stored in the block group descriptors. >> >> To allow easy migration of existing Next3 installations, I took the liberty >> of 'burning' the old 'exclude_inode' compatible flag and using a new >> 'exclude_bitmap' comaptible flag, to state the exclude bitmap blocks are stored >> in the group descriptors. >> >> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxxxxx> >> --- >> lib/ext2fs/ext2_fs.h | 13 +++++++++---- >> 1 files changed, 9 insertions(+), 4 deletions(-) >> >> diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h >> index 54cb3d4..f1f0e19 100644 >> --- a/lib/ext2fs/ext2_fs.h >> +++ b/lib/ext2fs/ext2_fs.h >> @@ -142,7 +142,8 @@ struct ext2_group_desc >> __u16 bg_free_inodes_count; /* Free inodes count */ >> __u16 bg_used_dirs_count; /* Directories count */ >> __u16 bg_flags; >> - __u32 bg_reserved[2]; >> + __u32 bg_exclude_bitmap; /* Exclude bitmap block */ > > I'd prefer if these comments were "Snapshot exclude bitmap block" so > that it is more clear what an exclude bitmap is used for. I'll change that. > > For consistency, it would also be good to name these "_lo" to match the > kernel fields. > That's a major cleanup. Forgive me for not picking up that glove... >> + __u32 bg_reserved[1]; >> __u16 bg_itable_unused; /* Unused inodes count */ >> __u16 bg_checksum; /* crc16(s_uuid+grouo_num+group_desc)*/ >> }; >> @@ -159,7 +160,8 @@ struct ext4_group_desc >> __u16 bg_free_inodes_count; /* Free inodes count */ >> __u16 bg_used_dirs_count; /* Directories count */ >> __u16 bg_flags; /* EXT4_BG_flags (INODE_UNINIT, etc) */ >> - __u32 bg_reserved[2]; /* Likely block/inode bitmap checksum */ >> + __u32 bg_exclude_bitmap; /* Exclude bitmap block */ >> + __u32 bg_reserved[1]; /* Likely block/inode bitmap checksum */ >> __u16 bg_itable_unused; /* Unused inodes count */ >> __u16 bg_checksum; /* crc16(sb_uuid+group+desc) */ >> __u32 bg_block_bitmap_hi; /* Blocks bitmap block MSB */ >> >> @@ -169,12 +171,14 @@ struct ext4_group_desc >> __u16 bg_free_inodes_count_hi;/* Free inodes count MSB */ >> __u16 bg_used_dirs_count_hi; /* Directories count MSB */ >> __u16 bg_itable_unused_hi; /* Unused inodes count MSB */ >> - __u32 bg_reserved2[3]; >> + __u32 bg_exclude_bitmap_hi; /* Exclude bitmap block MSB */ >> + __u32 bg_reserved2[2]; >> }; >> >> #define EXT2_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not initialized */ >> #define EXT2_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not initialized */ >> #define EXT2_BG_INODE_ZEROED 0x0004 /* On-disk itable initialized to zero */ >> +#define EXT2_BG_EXCLUDE_UNINIT 0x0008 /* Exclude bitmap not initialized */ >> >> /* >> * Data structures used by the directory indexing feature >> @@ -670,7 +674,8 @@ struct ext2_super_block { >> #define EXT2_FEATURE_COMPAT_RESIZE_INODE 0x0010 >> #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020 >> #define EXT2_FEATURE_COMPAT_LAZY_BG 0x0040 >> -#define EXT2_FEATURE_COMPAT_EXCLUDE_INODE 0x0080 >> +/* #define EXT2_FEATURE_COMPAT_EXCLUDE_INODE 0x0080 not used */ >> +#define EXT2_FEATURE_COMPAT_EXCLUDE_BITMAP 0x0100 >> >> #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001 >> #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002 >> -- >> 1.7.0.4 > > > Cheers, Andreas > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
