Btrfs: very simple readdir readahead

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2007-03-25 14:03:08 -04:00 committed by David Woodhouse
parent 134e973134
commit dcea79152c

View File

@ -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]++;