From 03bdb5ac58a2144dfe8cfd73347fdb9f57e2e062 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Sun, 18 Jul 2010 10:42:26 +0900 Subject: nilfs2: apply read-ahead for nilfs_btree_lookup_contig This applies read-ahead to nilfs_btree_do_lookup and nilfs_btree_lookup_contig functions and extends them to read ahead siblings of level 1 btree nodes that hold data blocks. At present, the read-ahead is not applied to most btree operations; only get_block() callback function, which is used during read of regular files or directories, receives the benefit. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/btree.c | 50 +++++++++++++++++++++++++++++++++----------------- 1 file changed, 33 insertions(+), 17 deletions(-) (limited to 'fs/nilfs2/btree.c') diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index d3faa0bba171..300c2bc00c3f 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -504,9 +504,11 @@ static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr, static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree, struct nilfs_btree_path *path, - __u64 key, __u64 *ptrp, int minlevel) + __u64 key, __u64 *ptrp, int minlevel, + int readahead) { struct nilfs_btree_node *node; + struct nilfs_btree_readahead_info p, *ra; __u64 ptr; int level, index, found, ncmax, ret; @@ -523,10 +525,20 @@ static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree, ncmax = nilfs_btree_nchildren_per_block(btree); - for (level--; level >= minlevel; level--) { - ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh); + while (--level >= minlevel) { + ra = NULL; + if (level == NILFS_BTREE_LEVEL_NODE_MIN && readahead) { + p.node = nilfs_btree_get_node(btree, path, level + 1, + &p.ncmax); + p.index = index; + p.max_ra_blocks = 7; + ra = &p; + } + ret = __nilfs_btree_get_block(btree, ptr, &path[level].bp_bh, + ra); if (ret < 0) return ret; + node = nilfs_btree_get_nonroot_node(path, level); if (nilfs_btree_bad_node(node, level)) return -EINVAL; @@ -601,7 +613,7 @@ static int nilfs_btree_lookup(const struct nilfs_bmap *btree, if (path == NULL) return -ENOMEM; - ret = nilfs_btree_do_lookup(btree, path, key, ptrp, level); + ret = nilfs_btree_do_lookup(btree, path, key, ptrp, level, 0); nilfs_btree_free_path(path); @@ -618,12 +630,13 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *btree, sector_t blocknr; int level = NILFS_BTREE_LEVEL_NODE_MIN; int ret, cnt, index, maxlevel, ncmax; + struct nilfs_btree_readahead_info p; path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; - ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level); + ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level, 1); if (ret < 0) goto out; @@ -662,17 +675,20 @@ static int nilfs_btree_lookup_contig(const struct nilfs_bmap *btree, break; /* look-up right sibling node */ - node = nilfs_btree_get_node(btree, path, level + 1, &ncmax); - index = path[level + 1].bp_index + 1; - if (index >= nilfs_btree_node_get_nchildren(node) || - nilfs_btree_node_get_key(node, index) != key + cnt) + p.node = nilfs_btree_get_node(btree, path, level + 1, &p.ncmax); + p.index = path[level + 1].bp_index + 1; + p.max_ra_blocks = 7; + if (p.index >= nilfs_btree_node_get_nchildren(p.node) || + nilfs_btree_node_get_key(p.node, p.index) != key + cnt) break; - ptr2 = nilfs_btree_node_get_ptr(node, index, ncmax); - path[level + 1].bp_index = index; + ptr2 = nilfs_btree_node_get_ptr(p.node, p.index, p.ncmax); + path[level + 1].bp_index = p.index; brelse(path[level].bp_bh); path[level].bp_bh = NULL; - ret = nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh); + + ret = __nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh, + &p); if (ret < 0) goto out; node = nilfs_btree_get_nonroot_node(path, level); @@ -1147,7 +1163,7 @@ static int nilfs_btree_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr) return -ENOMEM; ret = nilfs_btree_do_lookup(btree, path, key, NULL, - NILFS_BTREE_LEVEL_NODE_MIN); + NILFS_BTREE_LEVEL_NODE_MIN, 0); if (ret != -ENOENT) { if (ret == 0) ret = -EEXIST; @@ -1484,7 +1500,7 @@ static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key) return -ENOMEM; ret = nilfs_btree_do_lookup(btree, path, key, NULL, - NILFS_BTREE_LEVEL_NODE_MIN); + NILFS_BTREE_LEVEL_NODE_MIN, 0); if (ret < 0) goto out; @@ -1955,7 +1971,7 @@ static int nilfs_btree_propagate(struct nilfs_bmap *btree, level = NILFS_BTREE_LEVEL_DATA; } - ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1); + ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0); if (ret < 0) { if (unlikely(ret == -ENOENT)) printk(KERN_CRIT "%s: key = %llu, level == %d\n", @@ -2147,7 +2163,7 @@ static int nilfs_btree_assign(struct nilfs_bmap *btree, level = NILFS_BTREE_LEVEL_DATA; } - ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1); + ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0); if (ret < 0) { WARN_ON(ret == -ENOENT); goto out; @@ -2201,7 +2217,7 @@ static int nilfs_btree_mark(struct nilfs_bmap *btree, __u64 key, int level) if (path == NULL) return -ENOMEM; - ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1); + ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1, 0); if (ret < 0) { WARN_ON(ret == -ENOENT); goto out; -- cgit v1.2.3