[XFS] make btree root in inode support generic

The bmap btree is rooted in the inode and not in a disk block. Make the support for this feature more generic by adding a btree flag to for this feature instead of relying on the XFS_BTNUM_BMAP btnum check. Also clean up xfs_btree_get_block where this new flag is used. Based upon a patch from Dave Chinner. SGI-PV: 985583 SGI-Modid: xfs-linux-melb:xfs-kern:32180a Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: Bill O'Donnell <billodo@sgi.com> Signed-off-by: David Chinner <david@fromorbit.com>

[XFS] make btree root in inode support generic
The bmap btree is rooted in the inode and not in a disk block. Make the support for this feature more generic by adding a btree flag to for this feature instead of relying on the XFS_BTNUM_BMAP btnum check. Also clean up xfs_btree_get_block where this new flag is used. Based upon a patch from Dave Chinner. SGI-PV: 985583 SGI-Modid: xfs-linux-melb:xfs-kern:32180a Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: Bill O'Donnell <billodo@sgi.com> Signed-off-by: David Chinner <david@fromorbit.com>
Christoph Hellwig · Lachlan McIlroy
1 parent de227dd960
Showing 3 changed files with 33 additions and 20 deletions Side-by-side Diff
fs/xfs/xfs_bmap_btree.c
fs/xfs/xfs_btree.c
fs/xfs/xfs_btree.h
@@ -2656,6 +2656,7 @@
 	cur->bc_blocklog = mp->m_sb.sb_blocklog;
  
 	cur->bc_ops = &xfs_bmbt_ops;
+	cur->bc_flags = XFS_BTREE_ROOT_IN_INODE;
  
 	cur->bc_private.b.forksize = XFS_IFORK_SIZE(ip, whichfork);
 	cur->bc_private.b.ip = ip;
@@ -422,32 +422,39 @@
 }
  
 /*
+ * Get a the root block which is stored in the inode.
+ *
+ * For now this btree implementation assumes the btree root is always
+ * stored in the if_broot field of an inode fork.
+ */
+STATIC struct xfs_btree_block *
+xfs_btree_get_iroot(
+       struct xfs_btree_cur    *cur)
+{
+       struct xfs_ifork        *ifp;
+
+       ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
+       return (struct xfs_btree_block *)ifp->if_broot;
+}
+
+/*
  * Retrieve the block pointer from the cursor at the given level.
- * This may be a bmap btree root or from a buffer.
+ * This may be an inode btree root or from a buffer.
  */
-STATIC xfs_btree_block_t *		/* generic btree block pointer */
+STATIC struct xfs_btree_block *		/* generic btree block pointer */
 xfs_btree_get_block(
-	xfs_btree_cur_t		*cur,	/* btree cursor */
+	struct xfs_btree_cur	*cur,	/* btree cursor */
 	int			level,	/* level in btree */
-	xfs_buf_t		**bpp)	/* buffer containing the block */
+	struct xfs_buf		**bpp)	/* buffer containing the block */
 {
-	xfs_btree_block_t	*block;	/* return value */
-	xfs_buf_t		*bp;	/* return buffer */
-	xfs_ifork_t		*ifp;	/* inode fork pointer */
-	int			whichfork; /* data or attr fork */
-
-	if (cur->bc_btnum == XFS_BTNUM_BMAP && level == cur->bc_nlevels - 1) {
-		whichfork = cur->bc_private.b.whichfork;
-		ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, whichfork);
-		block = (xfs_btree_block_t *)ifp->if_broot;
-		bp = NULL;
-	} else {
-		bp = cur->bc_bufs[level];
-		block = XFS_BUF_TO_BLOCK(bp);
+	if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
+	    (level == cur->bc_nlevels - 1)) {
+		*bpp = NULL;
+		return xfs_btree_get_iroot(cur);
 	}
-	ASSERT(block != NULL);
-	*bpp = bp;
-	return block;
+
+	*bpp = cur->bc_bufs[level];
+	return XFS_BUF_TO_BLOCK(*bpp);
 }
  
 /*
@@ -170,6 +170,7 @@
 	struct xfs_trans	*bc_tp;	/* transaction we're in, if any */
 	struct xfs_mount	*bc_mp;	/* file system mount struct */
 	const struct xfs_btree_ops *bc_ops;
+	uint			bc_flags; /* btree features - below */
 	union {
 		xfs_alloc_rec_incore_t	a;
 		xfs_bmbt_irec_t		b;
@@ -200,6 +201,10 @@
 		} b;
 	}		bc_private;	/* per-btree type data */
 } xfs_btree_cur_t;
+
+/* cursor flags */
+#define XFS_BTREE_ROOT_IN_INODE		(1<<1)	/* root may be variable size */
+
  
 #define	XFS_BTREE_NOERROR	0
 #define	XFS_BTREE_ERROR		1
...	...	@@ -2656,6 +2656,7 @@
2656	2656	cur->bc_blocklog = mp->m_sb.sb_blocklog;
2657	2657
2658	2658	cur->bc_ops = &xfs_bmbt_ops;
	2659	+ cur->bc_flags = XFS_BTREE_ROOT_IN_INODE;
2659	2660
2660	2661	cur->bc_private.b.forksize = XFS_IFORK_SIZE(ip, whichfork);
2661	2662	cur->bc_private.b.ip = ip;
...	...	@@ -422,32 +422,39 @@
422	422	}
423	423
424	424	/*
	425	+ * Get a the root block which is stored in the inode.
	426	+ *
	427	+ * For now this btree implementation assumes the btree root is always
	428	+ * stored in the if_broot field of an inode fork.
	429	+ */
	430	+STATIC struct xfs_btree_block *
	431	+xfs_btree_get_iroot(
	432	+ struct xfs_btree_cur *cur)
	433	+{
	434	+ struct xfs_ifork *ifp;
	435	+
	436	+ ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
	437	+ return (struct xfs_btree_block *)ifp->if_broot;
	438	+}
	439	+
	440	+/*
425	441	* Retrieve the block pointer from the cursor at the given level.
426		- * This may be a bmap btree root or from a buffer.
	442	+ * This may be an inode btree root or from a buffer.
427	443	*/
428		-STATIC xfs_btree_block_t * /* generic btree block pointer */
	444	+STATIC struct xfs_btree_block * /* generic btree block pointer */
429	445	xfs_btree_get_block(
430		- xfs_btree_cur_t cur, / btree cursor */
	446	+ struct xfs_btree_cur cur, / btree cursor */
431	447	int level, /* level in btree */
432		- xfs_buf_t *bpp) / buffer containing the block */
	448	+ struct xfs_buf *bpp) / buffer containing the block */
433	449	{
434		- xfs_btree_block_t block; / return value */
435		- xfs_buf_t bp; / return buffer */
436		- xfs_ifork_t ifp; / inode fork pointer */
437		- int whichfork; /* data or attr fork */
438		-
439		- if (cur->bc_btnum == XFS_BTNUM_BMAP && level == cur->bc_nlevels - 1) {
440		- whichfork = cur->bc_private.b.whichfork;
441		- ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, whichfork);
442		- block = (xfs_btree_block_t *)ifp->if_broot;
443		- bp = NULL;
444		- } else {
445		- bp = cur->bc_bufs[level];
446		- block = XFS_BUF_TO_BLOCK(bp);
	450	+ if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
	451	+ (level == cur->bc_nlevels - 1)) {
	452	+ *bpp = NULL;
	453	+ return xfs_btree_get_iroot(cur);
447	454	}
448		- ASSERT(block != NULL);
449		- *bpp = bp;
450		- return block;
	455	+
	456	+ *bpp = cur->bc_bufs[level];
	457	+ return XFS_BUF_TO_BLOCK(*bpp);
451	458	}
452	459
453	460	/*
...	...	@@ -170,6 +170,7 @@
170	170	struct xfs_trans bc_tp; / transaction we're in, if any */
171	171	struct xfs_mount bc_mp; / file system mount struct */
172	172	const struct xfs_btree_ops *bc_ops;
	173	+ uint bc_flags; /* btree features - below */
173	174	union {
174	175	xfs_alloc_rec_incore_t a;
175	176	xfs_bmbt_irec_t b;
...	...	@@ -200,6 +201,10 @@
200	201	} b;
201	202	} bc_private; /* per-btree type data */
202	203	} xfs_btree_cur_t;
	204	+
	205	+/* cursor flags */
	206	+#define XFS_BTREE_ROOT_IN_INODE (1<<1) /* root may be variable size */
	207	+
203	208
204	209	#define XFS_BTREE_NOERROR 0
205	210	#define XFS_BTREE_ERROR 1