Commit 8186e517 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Lachlan McIlroy
Browse files

[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: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: default avatarBill O'Donnell <billodo@sgi.com>
Signed-off-by: default avatarDavid Chinner <david@fromorbit.com>
parent de227dd9

fs/xfs/xfs_bmap_btree.c

+1 −0
Original line number Diff line number Diff line
@@ -2656,6 +2656,7 @@ xfs_bmbt_init_cursor( 
	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;

fs/xfs/xfs_btree.c

+27 −20
Original line number Diff line number Diff line
@@ -421,33 +421,40 @@ xfs_btree_dup_cursor( 
	return 0;

}



/*

 * 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);

}



/*

fs/xfs/xfs_btree.h

+5 −0
Original line number Diff line number Diff line
@@ -170,6 +170,7 @@ typedef struct xfs_btree_cur 
	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;
@@ -201,6 +202,10 @@ typedef struct xfs_btree_cur 
	}		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

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