[XFS] 929045 567344 This mod re-organizes some of the in-core file extent

code to prepare for an upcoming mod which will introduce multi-level
in-core extent allocations. Although the in-core extent management is
using a new code path in this mod, the functionality remains the same. 
Major changes include:	- Introduce 10 new subroutines which re-orgainze
the existing code but	do NOT change functionality:	    
xfs_iext_get_ext()	   xfs_iext_insert()	     xfs_iext_add()	  
 xfs_iext_remove()	   xfs_iext_remove_inline()	   
xfs_iext_remove_direct()	 xfs_iext_realloc_direct()	  
xfs_iext_direct_to_inline()	    xfs_iext_inline_to_direct()        
xfs_iext_destroy() - Remove 2 subroutines (functionality moved to new
subroutines above):	    xfs_iext_realloc() -replaced by xfs_iext_add()
and xfs_iext_remove()	      xfs_bmap_insert_exlist() - replaced by
xfs_iext_insert()	  xfs_bmap_delete_exlist() - replaced by
xfs_iext_remove() - Replace all hard-coded (indexed) extent assignments
with a call to	 xfs_iext_get_ext() - Replace all extent record pointer
arithmetic (ep++, ep--, base + lastx,..)   with calls to
xfs_iext_get_ext() - Update comments to remove the idea of a single
"extent list" and   introduce "extent record" terminology instead

SGI-PV: 928864
SGI-Modid: xfs-linux-melb:xfs-kern:207390a
Signed-off-by: Mandy Kirkconnell <alkirkco@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/xfs/quota/xfs_qm.c

@@ -1704,9 +1704,9 @@ xfs_qm_get_rtblks(
 	xfs_qcnt_t	*O_rtblks)
 {
 	xfs_filblks_t	rtblks;			/* total rt blks */
+	xfs_extnum_t	idx;			/* extent record index */
 	xfs_ifork_t	*ifp;			/* inode fork pointer */
 	xfs_extnum_t	nextents;		/* number of extent entries */
-	xfs_bmbt_rec_t	*base;			/* base of extent array */
 	xfs_bmbt_rec_t	*ep;			/* pointer to an extent entry */
 	int		error;
 
@@ -1717,10 +1717,11 @@ xfs_qm_get_rtblks(
 			return error;
 	}
 	rtblks = 0;
-	nextents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
-	base = &ifp->if_u1.if_extents[0];
-	for (ep = base; ep < &base[nextents]; ep++)
+	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	for (idx = 0; idx < nextents; idx++) {
+		ep = xfs_iext_get_ext(ifp, idx);
 		rtblks += xfs_bmbt_get_blockcount(ep);
+	}
 	*O_rtblks = (xfs_qcnt_t)rtblks;
 	return 0;
 }

fs/xfs/xfs_bmap.h

@@ -20,6 +20,7 @@
 
 struct getbmap;
 struct xfs_bmbt_irec;
+struct xfs_ifork;
 struct xfs_inode;
 struct xfs_mount;
 struct xfs_trans;
@@ -347,7 +348,8 @@ xfs_bmap_count_blocks(
  */
 int
 xfs_check_nostate_extents(
-	xfs_bmbt_rec_t		*ep,
+	struct xfs_ifork	*ifp,
+	xfs_extnum_t		idx,
 	xfs_extnum_t		num);
 
 #endif	/* __KERNEL__ */

fs/xfs/xfs_bmap_btree.c

@@ -2754,7 +2754,7 @@ xfs_bmbt_update(
 }
 
 /*
- * Check an extent list, which has just been read, for
+ * Check extent records, which have just been read, for
  * any bit in the extent flag field. ASSERT on debug
  * kernels, as this condition should not occur.
  * Return an error condition (1) if any flags found,
@@ -2763,10 +2763,14 @@ xfs_bmbt_update(
 
 int
 xfs_check_nostate_extents(
-	xfs_bmbt_rec_t		*ep,
+	xfs_ifork_t		*ifp,
+	xfs_extnum_t		idx,
 	xfs_extnum_t		num)
 {
-	for (; num > 0; num--, ep++) {
+	xfs_bmbt_rec_t		*ep;
+
+	for (; num > 0; num--, idx++) {
+		ep = xfs_iext_get_ext(ifp, idx);
 		if ((ep->l0 >>
 		     (64 - BMBT_EXNTFLAG_BITLEN)) != 0) {
 			ASSERT(0);

fs/xfs/xfs_inode.h

@@ -70,12 +70,6 @@ typedef struct xfs_ifork {
  */
 #define	XFS_IMAP_LOOKUP		0x1
 
-/*
- * Maximum number of extent pointers in if_u1.if_extents.
- */
-#define	XFS_MAX_INCORE_EXTENTS	32768
-
-
 #ifdef __KERNEL__
 struct bhv_desc;
 struct cred;
@@ -440,6 +434,18 @@ xfs_inode_t	*xfs_vtoi(struct vnode *vp);
 
 void		xfs_synchronize_atime(xfs_inode_t *);
 
+xfs_bmbt_rec_t	*xfs_iext_get_ext(xfs_ifork_t *, xfs_extnum_t);
+void		xfs_iext_insert(xfs_ifork_t *, xfs_extnum_t, xfs_extnum_t,
+				xfs_bmbt_irec_t *);
+void		xfs_iext_add(xfs_ifork_t *, xfs_extnum_t, int);
+void		xfs_iext_remove(xfs_ifork_t *, xfs_extnum_t, int);
+void		xfs_iext_remove_inline(xfs_ifork_t *, xfs_extnum_t, int);
+void		xfs_iext_remove_direct(xfs_ifork_t *, xfs_extnum_t, int);
+void		xfs_iext_realloc_direct(xfs_ifork_t *, int);
+void		xfs_iext_direct_to_inline(xfs_ifork_t *, xfs_extnum_t);
+void		xfs_iext_inline_to_direct(xfs_ifork_t *, int);
+void		xfs_iext_destroy(xfs_ifork_t *);
+
 #define xfs_ipincount(ip)	((unsigned int) atomic_read(&ip->i_pincount))
 
 #ifdef DEBUG