From dcea79152cfb7cf244bdd9c23f4291831ffd6adf Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Sun, 25 Mar 2007 14:03:08 -0400 Subject: [PATCH] Btrfs: very simple readdir readahead Signed-off-by: Chris Mason --- fs/btrfs/super.c | 38 +++++++++++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index f96bd92155cc..e76fcd80db6a 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -332,6 +332,34 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, return d_splice_alias(inode, dentry); } +static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path) +{ + struct buffer_head *bh; + struct btrfs_node *node; + int i; + int nritems; + u64 objectid; + u64 item_objectid; + u64 blocknr; + int slot; + + if (!path->nodes[1]) + return; + node = btrfs_buffer_node(path->nodes[1]); + slot = path->slots[1]; + objectid = btrfs_disk_key_objectid(&node->ptrs[slot].key); + nritems = btrfs_header_nritems(&node->header); + for (i = slot; i < nritems; i++) { + item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key); + if (item_objectid != objectid) + break; + blocknr = btrfs_node_blockptr(node, i); + bh = sb_getblk(root->fs_info->sb, blocknr); + ll_rw_block(READ, 1, &bh); + brelse(bh); + } + +} static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir) { struct inode *inode = filp->f_path.dentry->d_inode; @@ -358,6 +386,7 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir) goto err; } advance = 0; + reada_leaves(root, &path); while(1) { leaf = btrfs_buffer_leaf(path.nodes[0]); nritems = btrfs_header_nritems(&leaf->header); @@ -370,13 +399,8 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir) leaf = btrfs_buffer_leaf(path.nodes[0]); nritems = btrfs_header_nritems(&leaf->header); slot = path.slots[0]; -#if 0 - page_cache_readahead( - inode->i_sb->s_bdev->bd_inode->i_mapping, - &filp->f_ra, filp, - path.nodes[0]->b_blocknr >> - (PAGE_CACHE_SHIFT - inode->i_blkbits), 1); -#endif + if (path.nodes[1] && path.slots[1] == 0) + reada_leaves(root, &path); } else { slot++; path.slots[0]++; -- 2.20.1