提交 d548ee51 编写于 作者: Y Yan 提交者: Chris Mason

Btrfs: Add a helper that finds previous extent item

Signed-off-by: NChris Mason <chris.mason@oracle.com>
上级 5b92ee72
......@@ -33,6 +33,28 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
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 @@ static int cache_block_group(struct btrfs_root *root,
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 @@ static int cache_block_group(struct btrfs_root *root,
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 @@ struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
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 @@ u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
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 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
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 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
if (ret < 0)
goto error;
if (path->slots[0] > 0) {
path->slots[0]--;
}
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);
ret = find_previous_extent(root, path);
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];
......
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