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Btrfs: Add BH_Defrag to mark buffers that are in need of defragging

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This allows the tree walking code to defrag only the newly allocated
buffers, it seems to be a good balance between perfect defragging and the
performance hit of repeatedly reallocating blocks.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2007-08-10 14:42:37 -04:00
committed by David Woodhouse
parent e9d0b13b5b
commit f2183bde1a
4 changed files with 18 additions and 11 deletions
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22
fs/btrfs/ctree.c
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@ -175,6 +175,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
int end_slot;
int i;
int err = 0;
int parent_level;
if (trans->transaction != root->fs_info->running_transaction) {
printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
@ -188,6 +189,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
}
parent_node = btrfs_buffer_node(parent);
parent_nritems = btrfs_header_nritems(&parent_node->header);
parent_level = btrfs_header_level(&parent_node->header);
start_slot = 0;
end_slot = parent_nritems;
@ -215,13 +217,16 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
cur_bh = btrfs_find_tree_block(root, blocknr);
if (!cur_bh || !buffer_uptodate(cur_bh) ||
buffer_locked(cur_bh)) {
buffer_locked(cur_bh) || !buffer_defrag(cur_bh)) {
if (cache_only) {
brelse(cur_bh);
continue;
}
brelse(cur_bh);
cur_bh = read_tree_block(root, blocknr);
if (!cur_bh || !buffer_uptodate(cur_bh) ||
buffer_locked(cur_bh)) {
brelse(cur_bh);
cur_bh = read_tree_block(root, blocknr);
}
}
if (search_start == 0)
search_start = last_block & ~((u64)65535);
@ -232,6 +237,9 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
if (err)
break;
search_start = bh_blocknr(tmp_bh);
*last_ret = search_start;
if (parent_level == 1)
clear_buffer_defrag(tmp_bh);
brelse(tmp_bh);
}
return err;
@ -811,16 +819,10 @@ static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
clear_radix_bit(&found, blocknr);
if (nread > 32)
continue;
if (direction > 0 && cluster_start <= blocknr &&
cluster_start + 8 > blocknr) {
cluster_start = blocknr;
if (close_blocks(cluster_start, blocknr)) {
readahead_tree_block(root, blocknr);
nread++;
} else if (direction < 0 && cluster_start >= blocknr &&
blocknr + 8 > cluster_start) {
cluster_start = blocknr;
readahead_tree_block(root, blocknr);
nread++;
}
}
}