Btrfs: Add a helper that finds previous extent item
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b801eb4..cc89df4 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -33,6 +33,28 @@
btrfs_root *extent_root);
static int del_pending_extents(struct btrfs_trans_handle *trans, struct
btrfs_root *extent_root);
+static int find_previous_extent(struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ int ret;
+
+ while(1) {
+ if (path->slots[0] == 0) {
+ ret = btrfs_prev_leaf(root, path);
+ if (ret != 0)
+ return ret;
+ } else {
+ path->slots[0]--;
+ }
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
+ return 0;
+ }
+ return 1;
+}
static int cache_block_group(struct btrfs_root *root,
struct btrfs_block_group_cache *block_group)
@@ -65,16 +87,19 @@
first_free = block_group->key.objectid;
key.objectid = block_group->key.objectid;
key.offset = 0;
-
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-
if (ret < 0)
return ret;
-
- if (ret && path->slots[0] > 0)
- path->slots[0]--;
-
+ ret = find_previous_extent(root, path);
+ if (ret < 0)
+ return ret;
+ if (ret == 0) {
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid + key.offset > first_free)
+ first_free = key.objectid + key.offset;
+ }
while(1) {
leaf = path->nodes[0];
slot = path->slots[0];
@@ -88,15 +113,10 @@
break;
}
}
-
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid < block_group->key.objectid) {
- if (btrfs_key_type(&key) != BTRFS_EXTENT_REF_KEY &&
- key.objectid + key.offset > first_free)
- first_free = key.objectid + key.offset;
goto next;
}
-
if (key.objectid >= block_group->key.objectid +
block_group->key.offset) {
break;
@@ -162,11 +182,9 @@
return block_group;
return NULL;
}
-
static u64 noinline find_search_start(struct btrfs_root *root,
struct btrfs_block_group_cache **cache_ret,
- u64 search_start, int num,
- int data, int full_scan)
+ u64 search_start, int num, int data)
{
int ret;
struct btrfs_block_group_cache *cache = *cache_ret;
@@ -771,9 +789,7 @@
out:
btrfs_free_path(path);
return total_count;
-
}
-
int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 owner_objectid)
{
@@ -1422,7 +1438,7 @@
orig_search_start);
}
search_start = find_search_start(root, &block_group, search_start,
- total_needed, data, full_scan);
+ total_needed, data);
search_start = stripe_align(root, search_start);
cached_start = search_start;
btrfs_init_path(path);
@@ -1434,35 +1450,11 @@
ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
if (ret < 0)
goto error;
-
- if (path->slots[0] > 0) {
- path->slots[0]--;
- }
-
+ ret = find_previous_extent(root, path);
+ if (ret < 0)
+ goto error;
l = path->nodes[0];
btrfs_item_key_to_cpu(l, &key, path->slots[0]);
-
- /*
- * walk backwards to find the first extent item key
- */
- while(btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
- if (path->slots[0] == 0) {
- ret = btrfs_prev_leaf(root, path);
- if (ret != 0) {
- ret = btrfs_search_slot(trans, root, ins,
- path, 0, 0);
- if (ret < 0)
- goto error;
- if (path->slots[0] > 0)
- path->slots[0]--;
- break;
- }
- } else {
- path->slots[0]--;
- }
- l = path->nodes[0];
- btrfs_item_key_to_cpu(l, &key, path->slots[0]);
- }
while (1) {
l = path->nodes[0];
slot = path->slots[0];