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Commit dcea7915 authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse
Browse files

Btrfs: very simple readdir readahead 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 134e9731

fs/btrfs/super.c

+31 −7
Original line number Diff line number Diff line
@@ -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]++;