Btrfs: Add btree locking to the tree defragmentation code
The online btree defragger is simplified and rewritten to use
standard btree searches instead of a walk up / down mechanism.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 40f0e0c..7f4cc2b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -354,7 +354,6 @@
struct btrfs_key *progress)
{
struct extent_buffer *cur;
- struct extent_buffer *tmp;
u64 blocknr;
u64 gen;
u64 search_start = *last_ret;
@@ -370,9 +369,6 @@
int progress_passed = 0;
struct btrfs_disk_key disk_key;
- /* FIXME this code needs locking */
- return 0;
-
parent_level = btrfs_header_level(parent);
if (cache_only && parent_level != 1)
return 0;
@@ -454,20 +450,23 @@
if (search_start == 0)
search_start = last_block;
+ btrfs_tree_lock(cur);
err = __btrfs_cow_block(trans, root, cur, parent, i,
- &tmp, search_start,
+ &cur, search_start,
min(16 * blocksize,
(end_slot - i) * blocksize));
if (err) {
+ btrfs_tree_unlock(cur);
free_extent_buffer(cur);
break;
}
- search_start = tmp->start;
- last_block = tmp->start;
+ search_start = cur->start;
+ last_block = cur->start;
*last_ret = search_start;
if (parent_level == 1)
- btrfs_clear_buffer_defrag(tmp);
- free_extent_buffer(tmp);
+ btrfs_clear_buffer_defrag(cur);
+ btrfs_tree_unlock(cur);
+ free_extent_buffer(cur);
}
if (parent->map_token) {
unmap_extent_buffer(parent, parent->map_token,
@@ -2970,6 +2969,35 @@
return 1;
}
+int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
+ struct btrfs_key *key, int lowest_level)
+{
+ int level = lowest_level;
+ int slot;
+ struct extent_buffer *c;
+
+ while(level < BTRFS_MAX_LEVEL) {
+ if (!path->nodes[level])
+ return 1;
+
+ slot = path->slots[level] + 1;
+ c = path->nodes[level];
+ if (slot >= btrfs_header_nritems(c)) {
+ level++;
+ if (level == BTRFS_MAX_LEVEL) {
+ return 1;
+ }
+ continue;
+ }
+ if (level == 0)
+ btrfs_item_key_to_cpu(c, key, slot);
+ else
+ btrfs_node_key_to_cpu(c, key, slot);
+ return 0;
+ }
+ return 1;
+}
+
/*
* search the tree again to find a leaf with greater keys
* returns 0 if it found something or 1 if there are no greater leaves.
