xfs: introduce xfs_sb.c for sharing with libxfs

xfs_mount.c is shared with userspace, but the only functions that
are shared are to do with physical superblock manipulations. This
means that less than 25% of the xfs_mount.c code is actually shared
with userspace. Move all the superblock functions to xfs_sb.c and
share that instead with libxfs.

Note that this will leave all the in-core transaction related
superblock counter modifications in xfs_mount.c as none of that is
shared with userspace. With a few more small changes, xfs_mount.h
won't need to be shared with userspace anymore, either.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

fs/xfs/Makefile

@@ -47,6 +47,7 @@ xfs-y				+= xfs_aops.o \
 				   xfs_iops.o \
 				   xfs_itable.o \
 				   xfs_message.o \
+				   xfs_mount.o \
 				   xfs_mru_cache.o \
 				   xfs_rename.o \
 				   xfs_super.o \
@@ -81,7 +82,7 @@ xfs-y				+= xfs_alloc.o \
 				   xfs_inode_fork.o \
 				   xfs_inode_buf.o \
 				   xfs_log_recover.o \
-				   xfs_mount.o \
+				   xfs_sb.o \
 				   xfs_symlink_remote.o \
 				   xfs_trans_resv.o
 

fs/xfs/xfs_mount.h

@@ -291,14 +291,6 @@ xfs_daddr_to_agbno(struct xfs_mount *mp, xfs_daddr_t d)
 	return (xfs_agblock_t) do_div(ld, mp->m_sb.sb_agblocks);
 }
 
-/*
- * perag get/put wrappers for ref counting
- */
-struct xfs_perag *xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno);
-struct xfs_perag *xfs_perag_get_tag(struct xfs_mount *mp, xfs_agnumber_t agno,
-					int tag);
-void	xfs_perag_put(struct xfs_perag *pag);
-
 /*
  * Per-cpu superblock locking functions
  */
@@ -331,6 +323,8 @@ typedef struct xfs_mod_sb {
 extern int	xfs_log_sbcount(xfs_mount_t *);
 extern __uint64_t xfs_default_resblks(xfs_mount_t *mp);
 extern int	xfs_mountfs(xfs_mount_t *mp);
+extern int	xfs_initialize_perag(xfs_mount_t *mp, xfs_agnumber_t agcount,
+				     xfs_agnumber_t *maxagi);
 
 extern void	xfs_unmountfs(xfs_mount_t *);
 extern int	xfs_mod_incore_sb(xfs_mount_t *, xfs_sb_field_t, int64_t, int);
@@ -349,13 +343,4 @@ extern void	xfs_set_low_space_thresholds(struct xfs_mount *);
 
 #endif	/* __KERNEL__ */
 
-extern void	xfs_sb_calc_crc(struct xfs_buf	*);
-extern void	xfs_mod_sb(struct xfs_trans *, __int64_t);
-extern int	xfs_initialize_perag(struct xfs_mount *, xfs_agnumber_t,
-					xfs_agnumber_t *);
-extern void	xfs_sb_from_disk(struct xfs_sb *, struct xfs_dsb *);
-extern void	xfs_sb_to_disk(struct xfs_dsb *, struct xfs_sb *, __int64_t);
-
-extern const struct xfs_buf_ops xfs_sb_buf_ops;
-
 #endif	/* __XFS_MOUNT_H__ */

fs/xfs/xfs_sb.h

@@ -26,6 +26,7 @@
 
 struct xfs_buf;
 struct xfs_mount;
+struct xfs_trans;
 
 #define	XFS_SB_MAGIC		0x58465342	/* 'XFSB' */
 #define	XFS_SB_VERSION_1	1		/* 5.3, 6.0.1, 6.1 */
@@ -674,4 +675,23 @@ xfs_is_quota_inode(struct xfs_sb *sbp, xfs_ino_t ino)
 #define XFS_B_TO_FSBT(mp,b)	(((__uint64_t)(b)) >> (mp)->m_sb.sb_blocklog)
 #define XFS_B_FSB_OFFSET(mp,b)	((b) & (mp)->m_blockmask)
 
+/*
+ * perag get/put wrappers for ref counting
+ */
+extern struct xfs_perag *xfs_perag_get(struct xfs_mount *, xfs_agnumber_t);
+extern struct xfs_perag *xfs_perag_get_tag(struct xfs_mount *, xfs_agnumber_t,
+					   int tag);
+extern void	xfs_perag_put(struct xfs_perag *pag);
+extern int	xfs_initialize_perag_data(struct xfs_mount *, xfs_agnumber_t);
+
+extern void	xfs_sb_calc_crc(struct xfs_buf	*);
+extern void	xfs_mod_sb(struct xfs_trans *, __int64_t);
+extern void	xfs_sb_mount_common(struct xfs_mount *, struct xfs_sb *);
+extern void	xfs_sb_from_disk(struct xfs_sb *, struct xfs_dsb *);
+extern void	xfs_sb_to_disk(struct xfs_dsb *, struct xfs_sb *, __int64_t);
+extern void	xfs_sb_quota_from_disk(struct xfs_sb *sbp);
+
+extern const struct xfs_buf_ops xfs_sb_buf_ops;
+extern const struct xfs_buf_ops xfs_sb_quiet_buf_ops;
+
 #endif	/* __XFS_SB_H__ */