X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=fs%2Fxfs%2Flibxfs%2Fxfs_format.h;h=9590a069e5569a88942e4726382db7819d7884f7;hb=a6f83f00ad4b4e8a6c1cd14db495f40cf5ea7586;hp=a0ae572051de78b4169d5f363ba749f4030c170d;hpb=a230e95cc66a5a27e53459187ffcedb65b2782c3;p=cascardo%2Flinux.git

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index a0ae572051de..9590a069e556 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -100,7 +100,7 @@ typedef struct xfs_sb {
 	xfs_rfsblock_t	sb_dblocks;	/* number of data blocks */
 	xfs_rfsblock_t	sb_rblocks;	/* number of realtime blocks */
 	xfs_rtblock_t	sb_rextents;	/* number of realtime extents */
-	uuid_t		sb_uuid;	/* file system unique id */
+	uuid_t		sb_uuid;	/* user-visible file system unique id */
 	xfs_fsblock_t	sb_logstart;	/* starting block of log if internal */
 	xfs_ino_t	sb_rootino;	/* root inode number */
 	xfs_ino_t	sb_rbmino;	/* bitmap inode for realtime extents */
@@ -174,6 +174,7 @@ typedef struct xfs_sb {
 
 	xfs_ino_t	sb_pquotino;	/* project quota inode */
 	xfs_lsn_t	sb_lsn;		/* last write sequence */
+	uuid_t		sb_meta_uuid;	/* metadata file system unique id */
 
 	/* must be padded to 64 bit alignment */
 } xfs_sb_t;
@@ -190,7 +191,7 @@ typedef struct xfs_dsb {
 	__be64		sb_dblocks;	/* number of data blocks */
 	__be64		sb_rblocks;	/* number of realtime blocks */
 	__be64		sb_rextents;	/* number of realtime extents */
-	uuid_t		sb_uuid;	/* file system unique id */
+	uuid_t		sb_uuid;	/* user-visible file system unique id */
 	__be64		sb_logstart;	/* starting block of log if internal */
 	__be64		sb_rootino;	/* root inode number */
 	__be64		sb_rbmino;	/* bitmap inode for realtime extents */
@@ -260,6 +261,7 @@ typedef struct xfs_dsb {
 
 	__be64		sb_pquotino;	/* project quota inode */
 	__be64		sb_lsn;		/* last write sequence */
+	uuid_t		sb_meta_uuid;	/* metadata file system unique id */
 
 	/* must be padded to 64 bit alignment */
 } xfs_dsb_t;
@@ -458,9 +460,11 @@ xfs_sb_has_ro_compat_feature(
 
 #define XFS_SB_FEAT_INCOMPAT_FTYPE	(1 << 0)	/* filetype in dirent */
 #define XFS_SB_FEAT_INCOMPAT_SPINODES	(1 << 1)	/* sparse inode chunks */
+#define XFS_SB_FEAT_INCOMPAT_META_UUID	(1 << 2)	/* metadata UUID */
 #define XFS_SB_FEAT_INCOMPAT_ALL \
 		(XFS_SB_FEAT_INCOMPAT_FTYPE|	\
-		 XFS_SB_FEAT_INCOMPAT_SPINODES)
+		 XFS_SB_FEAT_INCOMPAT_SPINODES|	\
+		 XFS_SB_FEAT_INCOMPAT_META_UUID)
 
 #define XFS_SB_FEAT_INCOMPAT_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_ALL
 static inline bool
@@ -514,6 +518,18 @@ static inline bool xfs_sb_version_hassparseinodes(struct xfs_sb *sbp)
 		xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_SPINODES);
 }
 
+/*
+ * XFS_SB_FEAT_INCOMPAT_META_UUID indicates that the metadata UUID
+ * is stored separately from the user-visible UUID; this allows the
+ * user-visible UUID to be changed on V5 filesystems which have a
+ * filesystem UUID stamped into every piece of metadata.
+ */
+static inline bool xfs_sb_version_hasmetauuid(struct xfs_sb *sbp)
+{
+	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) &&
+		(sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID);
+}
+
 /*
  * end of superblock version macros
  */