From b524bfeee2152fa64b6210f28ced80489b9d2439 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 30 Oct 2008 16:54:43 +1100 Subject: [XFS] refactor xfs_btree_readahead From: Dave Chinner Refactor xfs_btree_readahead to make it more readable: (a) remove the inline xfs_btree_readahead wrapper and move all checks out of line into the main routine. (b) factor out helpers for short/long form btrees (c) move check for root in inodes from the callers into xfs_btree_readahead [hch: split out from a big patch and minor cleanups] SGI-PV: 985583 SGI-Modid: xfs-linux-melb:xfs-kern:32182a Signed-off-by: Christoph Hellwig Signed-off-by: Lachlan McIlroy Signed-off-by: Bill O'Donnell Signed-off-by: David Chinner --- fs/xfs/xfs_btree.c | 118 ++++++++++++++++++++++++++++++----------------------- 1 file changed, 68 insertions(+), 50 deletions(-) (limited to 'fs/xfs/xfs_btree.c') diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c index 59796b4..4d793e4 100644 --- a/fs/xfs/xfs_btree.c +++ b/fs/xfs/xfs_btree.c @@ -725,66 +725,84 @@ xfs_btree_reada_bufs( xfs_baread(mp->m_ddev_targp, d, mp->m_bsize * count); } +STATIC int +xfs_btree_readahead_lblock( + struct xfs_btree_cur *cur, + int lr, + struct xfs_btree_block *block) +{ + int rval = 0; + xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib); + xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib); + + if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) { + xfs_btree_reada_bufl(cur->bc_mp, left, 1); + rval++; + } + + if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) { + xfs_btree_reada_bufl(cur->bc_mp, right, 1); + rval++; + } + + return rval; +} + +STATIC int +xfs_btree_readahead_sblock( + struct xfs_btree_cur *cur, + int lr, + struct xfs_btree_block *block) +{ + int rval = 0; + xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib); + xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib); + + + if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) { + xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno, + left, 1); + rval++; + } + + if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) { + xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno, + right, 1); + rval++; + } + + return rval; +} + /* * Read-ahead btree blocks, at the given level. * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA. */ int -xfs_btree_readahead_core( - xfs_btree_cur_t *cur, /* btree cursor */ +xfs_btree_readahead( + struct xfs_btree_cur *cur, /* btree cursor */ int lev, /* level in btree */ int lr) /* left/right bits */ { - xfs_alloc_block_t *a; - xfs_bmbt_block_t *b; - xfs_inobt_block_t *i; - int rval = 0; + struct xfs_btree_block *block; + + /* + * No readahead needed if we are at the root level and the + * btree root is stored in the inode. + */ + if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && + (lev == cur->bc_nlevels - 1)) + return 0; + + if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev]) + return 0; - ASSERT(cur->bc_bufs[lev] != NULL); cur->bc_ra[lev] |= lr; - switch (cur->bc_btnum) { - case XFS_BTNUM_BNO: - case XFS_BTNUM_CNT: - a = XFS_BUF_TO_ALLOC_BLOCK(cur->bc_bufs[lev]); - if ((lr & XFS_BTCUR_LEFTRA) && be32_to_cpu(a->bb_leftsib) != NULLAGBLOCK) { - xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno, - be32_to_cpu(a->bb_leftsib), 1); - rval++; - } - if ((lr & XFS_BTCUR_RIGHTRA) && be32_to_cpu(a->bb_rightsib) != NULLAGBLOCK) { - xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno, - be32_to_cpu(a->bb_rightsib), 1); - rval++; - } - break; - case XFS_BTNUM_BMAP: - b = XFS_BUF_TO_BMBT_BLOCK(cur->bc_bufs[lev]); - if ((lr & XFS_BTCUR_LEFTRA) && be64_to_cpu(b->bb_leftsib) != NULLDFSBNO) { - xfs_btree_reada_bufl(cur->bc_mp, be64_to_cpu(b->bb_leftsib), 1); - rval++; - } - if ((lr & XFS_BTCUR_RIGHTRA) && be64_to_cpu(b->bb_rightsib) != NULLDFSBNO) { - xfs_btree_reada_bufl(cur->bc_mp, be64_to_cpu(b->bb_rightsib), 1); - rval++; - } - break; - case XFS_BTNUM_INO: - i = XFS_BUF_TO_INOBT_BLOCK(cur->bc_bufs[lev]); - if ((lr & XFS_BTCUR_LEFTRA) && be32_to_cpu(i->bb_leftsib) != NULLAGBLOCK) { - xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno, - be32_to_cpu(i->bb_leftsib), 1); - rval++; - } - if ((lr & XFS_BTCUR_RIGHTRA) && be32_to_cpu(i->bb_rightsib) != NULLAGBLOCK) { - xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno, - be32_to_cpu(i->bb_rightsib), 1); - rval++; - } - break; - default: - ASSERT(0); - } - return rval; + block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]); + + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) + return xfs_btree_readahead_lblock(cur, lr, block); + return xfs_btree_readahead_sblock(cur, lr, block); } /* -- cgit v1.1