From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Tue, 29 Jul 2008 12:29:20 -0700 (PDT) Received: from cuda.sgi.com ([192.48.176.15]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m6TJTGJL031464 for ; Tue, 29 Jul 2008 12:29:16 -0700 Received: from verein.lst.de (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id D56721947CC5 for ; Tue, 29 Jul 2008 12:30:27 -0700 (PDT) Received: from verein.lst.de (verein.lst.de [213.95.11.210]) by cuda.sgi.com with ESMTP id P9SBAxQyHQCQnleo for ; Tue, 29 Jul 2008 12:30:27 -0700 (PDT) Received: from verein.lst.de (localhost [127.0.0.1]) by verein.lst.de (8.12.3/8.12.3/Debian-7.1) with ESMTP id m6TJUUIF019203 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Tue, 29 Jul 2008 21:30:30 +0200 Received: (from hch@localhost) by verein.lst.de (8.12.3/8.12.3/Debian-6.6) id m6TJUTFb019201 for xfs@oss.sgi.com; Tue, 29 Jul 2008 21:30:29 +0200 Date: Tue, 29 Jul 2008 21:30:29 +0200 From: Christoph Hellwig Subject: [PATCH 05/21] refactor xfs_btree_readahead Message-ID: <20080729193029.GF19104@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename=xfs-btree-readahead-refactor Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: xfs@oss.sgi.com 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] Signed-off-by: Christoph Hellwig Index: linux-2.6-xfs/fs/xfs/xfs_btree.c =================================================================== --- linux-2.6-xfs.orig/fs/xfs/xfs_btree.c 2008-07-27 13:06:45.000000000 +0200 +++ linux-2.6-xfs/fs/xfs/xfs_btree.c 2008-07-28 17:41:41.000000000 +0200 @@ -709,66 +709,85 @@ 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_lblock *lb) +{ + int rval = 0; + xfs_fsblock_t left = be64_to_cpu(lb->bb_leftsib); + xfs_fsblock_t right = be64_to_cpu(lb->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_sblock *sb) +{ + int rval = 0; + xfs_agblock_t left = be32_to_cpu(sb->bb_leftsib); + xfs_agblock_t right = be32_to_cpu(sb->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_buf *bp; + + /* + * 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; + bp = cur->bc_bufs[lev]; + + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) + return xfs_btree_readahead_lblock(cur, lr, + XFS_BUF_TO_LBLOCK(bp)); + return xfs_btree_readahead_sblock(cur, lr, XFS_BUF_TO_SBLOCK(bp)); } /* Index: linux-2.6-xfs/fs/xfs/xfs_btree.h =================================================================== --- linux-2.6-xfs.orig/fs/xfs/xfs_btree.h 2008-07-27 13:06:45.000000000 +0200 +++ linux-2.6-xfs/fs/xfs/xfs_btree.h 2008-07-28 17:37:23.000000000 +0200 @@ -429,23 +429,10 @@ xfs_btree_reada_bufs( * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA. */ int /* readahead block count */ -xfs_btree_readahead_core( - xfs_btree_cur_t *cur, /* btree cursor */ - int lev, /* level in btree */ - int lr); /* left/right bits */ - -static inline int /* readahead block count */ xfs_btree_readahead( xfs_btree_cur_t *cur, /* btree cursor */ int lev, /* level in btree */ - int lr) /* left/right bits */ -{ - if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev]) - return 0; - - return xfs_btree_readahead_core(cur, lev, lr); -} - + int lr); /* left/right bits */ /* * Set the buffer for level "lev" in the cursor to bp, releasing Index: linux-2.6-xfs/fs/xfs/xfs_bmap_btree.c =================================================================== --- linux-2.6-xfs.orig/fs/xfs/xfs_bmap_btree.c 2008-07-27 13:06:45.000000000 +0200 +++ linux-2.6-xfs/fs/xfs/xfs_bmap_btree.c 2008-07-28 17:37:21.000000000 +0200 @@ -1721,8 +1721,9 @@ xfs_bmbt_decrement( XFS_BMBT_TRACE_CURSOR(cur, ENTRY); XFS_BMBT_TRACE_ARGI(cur, level); ASSERT(level < cur->bc_nlevels); - if (level < cur->bc_nlevels - 1) - xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA); + + xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA); + if (--cur->bc_ptrs[level] > 0) { XFS_BMBT_TRACE_CURSOR(cur, EXIT); *stat = 1; @@ -1743,8 +1744,7 @@ xfs_bmbt_decrement( for (lev = level + 1; lev < cur->bc_nlevels; lev++) { if (--cur->bc_ptrs[lev] > 0) break; - if (lev < cur->bc_nlevels - 1) - xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA); + xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA); } if (lev == cur->bc_nlevels) { XFS_BMBT_TRACE_CURSOR(cur, EXIT); @@ -1995,8 +1995,8 @@ xfs_bmbt_increment( XFS_BMBT_TRACE_CURSOR(cur, ENTRY); XFS_BMBT_TRACE_ARGI(cur, level); ASSERT(level < cur->bc_nlevels); - if (level < cur->bc_nlevels - 1) - xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA); + + xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA); block = xfs_bmbt_get_block(cur, level, &bp); #ifdef DEBUG if ((error = xfs_btree_check_lblock(cur, block, level, bp))) { @@ -2024,8 +2024,7 @@ xfs_bmbt_increment( #endif if (++cur->bc_ptrs[lev] <= be16_to_cpu(block->bb_numrecs)) break; - if (lev < cur->bc_nlevels - 1) - xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA); + xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA); } if (lev == cur->bc_nlevels) { XFS_BMBT_TRACE_CURSOR(cur, EXIT); --