From ce748eaa65f2e9392ba82726503c8d994ffd6393 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Wed, 29 Jul 2015 11:53:31 +1000 Subject: 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 Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_inode_buf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/xfs/libxfs/xfs_inode_buf.c') diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index 6526e7696184..268c00f4f83a 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -304,7 +304,7 @@ xfs_dinode_verify( return false; if (be64_to_cpu(dip->di_ino) != ip->i_ino) return false; - if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_uuid)) + if (!uuid_equal(&dip->di_uuid, &mp->m_sb.sb_meta_uuid)) return false; return true; } @@ -366,7 +366,7 @@ xfs_iread( if (xfs_sb_version_hascrc(&mp->m_sb)) { ip->i_d.di_version = 3; ip->i_d.di_ino = ip->i_ino; - uuid_copy(&ip->i_d.di_uuid, &mp->m_sb.sb_uuid); + uuid_copy(&ip->i_d.di_uuid, &mp->m_sb.sb_meta_uuid); } else ip->i_d.di_version = 2; return 0; -- cgit v1.2.3