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| author | Eric Sandeen <sandeen@sandeen.net> | 2015-07-29 11:53:31 +1000 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2015-07-29 11:53:31 +1000 |
| commit | ce748eaa65f2e9392ba82726503c8d994ffd6393 (patch) | |
| tree | ff3ec811268e84efbcebbf4b24ec23ff3438c1c7 /fs/xfs/libxfs/xfs_btree.c | |
| parent | bc0195aad0daa2ad5b0d76cce22b167bc3435590 (diff) | |
| download | lwn-ce748eaa65f2e9392ba82726503c8d994ffd6393.tar.gz lwn-ce748eaa65f2e9392ba82726503c8d994ffd6393.zip | |
xfs: create new metadata UUID field and incompat flag
This adds a new superblock field, sb_meta_uuid. If set, along with
a new incompat flag, the code will use that field on a V5 filesystem
to compare to metadata UUIDs, which allows us to change the user-
visible UUID at will. Userspace handles the setting and clearing
of the incompat flag as appropriate, as the UUID gets changed; i.e.
setting the user-visible UUID back to the original UUID (as stored in
the new field) will remove the incompatible feature flag.
If the incompat flag is not set, this copies the user-visible UUID into
into the meta_uuid slot in memory when the superblock is read from disk;
the meta_uuid field is not written back to disk in this case.
The remainder of this patch simply switches verifiers, initializers,
etc to use the new sb_meta_uuid field.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/libxfs/xfs_btree.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_btree.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index c72283dd8d44..f7d7ee7a2607 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -65,7 +65,8 @@ xfs_btree_check_lblock( if (xfs_sb_version_hascrc(&mp->m_sb)) { lblock_ok = lblock_ok && - uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid) && + uuid_equal(&block->bb_u.l.bb_uuid, + &mp->m_sb.sb_meta_uuid) && block->bb_u.l.bb_blkno == cpu_to_be64( bp ? bp->b_bn : XFS_BUF_DADDR_NULL); } @@ -115,7 +116,8 @@ xfs_btree_check_sblock( if (xfs_sb_version_hascrc(&mp->m_sb)) { sblock_ok = sblock_ok && - uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid) && + uuid_equal(&block->bb_u.s.bb_uuid, + &mp->m_sb.sb_meta_uuid) && block->bb_u.s.bb_blkno == cpu_to_be64( bp ? bp->b_bn : XFS_BUF_DADDR_NULL); } @@ -1000,7 +1002,7 @@ xfs_btree_init_block_int( if (flags & XFS_BTREE_CRC_BLOCKS) { buf->bb_u.l.bb_blkno = cpu_to_be64(blkno); buf->bb_u.l.bb_owner = cpu_to_be64(owner); - uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid); + uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid); buf->bb_u.l.bb_pad = 0; buf->bb_u.l.bb_lsn = 0; } @@ -1013,7 +1015,7 @@ xfs_btree_init_block_int( if (flags & XFS_BTREE_CRC_BLOCKS) { buf->bb_u.s.bb_blkno = cpu_to_be64(blkno); buf->bb_u.s.bb_owner = cpu_to_be32(__owner); - uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid); + uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid); buf->bb_u.s.bb_lsn = 0; } } |