[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>
This commit is contained in:
Christoph Hellwig 2008-10-30 16:54:22 +11:00 committed by Lachlan McIlroy
parent de227dd960
commit 8186e517fa
3 changed files with 35 additions and 22 deletions

View file

@ -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;

View file

@ -422,32 +422,39 @@ xfs_btree_dup_cursor(
}
/*
* Retrieve the block pointer from the cursor at the given level.
* This may be a bmap btree root or from a buffer.
* 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 xfs_btree_block_t * /* generic btree block pointer */
xfs_btree_get_block(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level in btree */
xfs_buf_t **bpp) /* buffer containing the block */
STATIC struct xfs_btree_block *
xfs_btree_get_iroot(
struct xfs_btree_cur *cur)
{
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 */
struct xfs_ifork *ifp;
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);
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 an inode btree root or from a buffer.
*/
STATIC struct xfs_btree_block * /* generic btree block pointer */
xfs_btree_get_block(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* level in btree */
struct xfs_buf **bpp) /* buffer containing the block */
{
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);
}
/*

View file

@ -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