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author | Eric Sandeen <sandeen@sandeen.net> | 2015-07-29 11:53:31 +1000 |
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committer | Dave Chinner <david@fromorbit.com> | 2015-07-29 11:53:31 +1000 |
commit | ce748eaa65f2e9392ba82726503c8d994ffd6393 (patch) | |
tree | ff3ec811268e84efbcebbf4b24ec23ff3438c1c7 /fs/xfs/libxfs/xfs_attr_leaf.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_attr_leaf.c')
-rw-r--r-- | fs/xfs/libxfs/xfs_attr_leaf.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c index e9d401ce93bb..33df52d97ec7 100644 --- a/fs/xfs/libxfs/xfs_attr_leaf.c +++ b/fs/xfs/libxfs/xfs_attr_leaf.c @@ -262,7 +262,7 @@ xfs_attr3_leaf_verify( if (ichdr.magic != XFS_ATTR3_LEAF_MAGIC) return false; - if (!uuid_equal(&hdr3->info.uuid, &mp->m_sb.sb_uuid)) + if (!uuid_equal(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid)) return false; if (be64_to_cpu(hdr3->info.blkno) != bp->b_bn) return false; @@ -1056,7 +1056,7 @@ xfs_attr3_leaf_create( hdr3->blkno = cpu_to_be64(bp->b_bn); hdr3->owner = cpu_to_be64(dp->i_ino); - uuid_copy(&hdr3->uuid, &mp->m_sb.sb_uuid); + uuid_copy(&hdr3->uuid, &mp->m_sb.sb_meta_uuid); ichdr.freemap[0].base = sizeof(struct xfs_attr3_leaf_hdr); } else { |