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Btrfs: Tune the automatic defrag code 

1) Forced defrag wasn't working properly (btrfsctl -d) because some
cache only checks were incorrect.

2) Defrag only the leaves unless in forced defrag mode.

3) Don't use complex logic to figure out if a leaf is needs defrag

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2007-10-25 15:43:18 -04:00
parent 18f16f7ba6
commit 5708b95916
2 changed files with 26 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
fs/btrfs/ctree.c
View File

@ -161,34 +161,6 @@ static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
return 0;
}
static int should_defrag_leaf(struct extent_buffer *leaf)
{
struct btrfs_key key;
u32 nritems;
if (btrfs_buffer_defrag(leaf))
return 1;
nritems = btrfs_header_nritems(leaf);
if (nritems == 0)
return 0;
btrfs_item_key_to_cpu(leaf, &key, 0);
if (key.type == BTRFS_DIR_ITEM_KEY)
return 1;
btrfs_item_key_to_cpu(leaf, &key, nritems - 1);
if (key.type == BTRFS_DIR_ITEM_KEY)
return 1;
if (nritems > 4) {
btrfs_item_key_to_cpu(leaf, &key, nritems / 2);
if (key.type == BTRFS_DIR_ITEM_KEY)
return 1;
}
return 0;
}
int btrfs_realloc_node(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *parent,
int start_slot, int cache_only, u64 *last_ret,
@ -208,6 +180,10 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
int uptodate;
u32 blocksize;
parent_level = btrfs_header_level(parent);
if (cache_only && parent_level != 1)
return 0;
if (trans->transaction != root->fs_info->running_transaction) {
printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
root->fs_info->running_transaction->transid);
@ -218,7 +194,6 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
root->fs_info->generation);
WARN_ON(1);
}
parent_level = btrfs_header_level(parent);
parent_nritems = btrfs_header_nritems(parent);
blocksize = btrfs_level_size(root, parent_level - 1);
@ -227,27 +202,26 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
if (parent_nritems == 1)
return 0;
if (root != root->fs_info->extent_root) {
struct btrfs_key first_key;
struct btrfs_key last_key;
btrfs_node_key_to_cpu(parent, &first_key, 0);
btrfs_node_key_to_cpu(parent, &last_key, parent_nritems - 1);
if (first_key.objectid != last_key.objectid)
return 0;
}
for (i = start_slot; i < end_slot; i++) {
int close = 1;
if (!parent->map_token) {
map_extent_buffer(parent,
btrfs_node_key_ptr_offset(i),
sizeof(struct btrfs_key_ptr),
&parent->map_token, &parent->kaddr,
&parent->map_start, &parent->map_len,
KM_USER1);
}
blocknr = btrfs_node_blockptr(parent, i);
if (last_block == 0)
last_block = blocknr;
if (i > 0) {
other = btrfs_node_blockptr(parent, i - 1);
close = close_blocks(blocknr, other, blocksize);
}
if (close && i < end_slot - 1) {
if (close && i < end_slot - 2) {
other = btrfs_node_blockptr(parent, i + 1);
close = close_blocks(blocknr, other, blocksize);
}
@ -255,15 +229,18 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
last_block = blocknr;
continue;
}
if (parent->map_token) {
unmap_extent_buffer(parent, parent->map_token,
KM_USER1);
parent->map_token = NULL;
}
cur = btrfs_find_tree_block(root, blocknr, blocksize);
if (cur)
uptodate = btrfs_buffer_uptodate(cur);
else
uptodate = 0;
if (!cur || !uptodate ||
(parent_level != 1 && !btrfs_buffer_defrag(cur)) ||
(parent_level == 1 && !should_defrag_leaf(cur))) {
if (!cur || !uptodate) {
if (cache_only) {
free_extent_buffer(cur);
continue;
@ -287,11 +264,17 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
break;
}
search_start = tmp->start;
last_block = tmp->start;
*last_ret = search_start;
if (parent_level == 1)
btrfs_clear_buffer_defrag(tmp);
free_extent_buffer(tmp);
}
if (parent->map_token) {
unmap_extent_buffer(parent, parent->map_token,
KM_USER1);
parent->map_token = NULL;
}
return err;
}

1
fs/btrfs/tree-defrag.c
View File

@ -183,7 +183,6 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
if (level == 0) {
goto out;
}
if (root->defrag_progress.objectid == 0) {
extent_buffer_get(root->node);
ret = btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);