btrfs: backref: rename and move remove_backref_node()

Also add comment explaining the cleanup progress, to differ it from
btrfs_backref_drop_node().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2020-03-23 15:42:25 +08:00 committed by David Sterba
parent b0fe7078d6
commit 023acb07bc
3 changed files with 53 additions and 48 deletions

View File

@ -2514,3 +2514,48 @@ struct btrfs_backref_edge *btrfs_backref_alloc_edge(
cache->nr_edges++;
return edge;
}
/*
* Drop the backref node from cache, also cleaning up all its
* upper edges and any uncached nodes in the path.
*
* This cleanup happens bottom up, thus the node should either
* be the lowest node in the cache or a detached node.
*/
void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
struct btrfs_backref_node *node)
{
struct btrfs_backref_node *upper;
struct btrfs_backref_edge *edge;
if (!node)
return;
BUG_ON(!node->lowest && !node->detached);
while (!list_empty(&node->upper)) {
edge = list_entry(node->upper.next, struct btrfs_backref_edge,
list[LOWER]);
upper = edge->node[UPPER];
list_del(&edge->list[LOWER]);
list_del(&edge->list[UPPER]);
btrfs_backref_free_edge(cache, edge);
if (RB_EMPTY_NODE(&upper->rb_node)) {
BUG_ON(!list_empty(&node->upper));
btrfs_backref_drop_node(cache, node);
node = upper;
node->lowest = 1;
continue;
}
/*
* Add the node to leaf node list if no other child block
* cached.
*/
if (list_empty(&upper->lower)) {
list_add_tail(&upper->lower, &cache->leaves);
upper->lowest = 1;
}
}
btrfs_backref_drop_node(cache, node);
}

View File

@ -350,4 +350,7 @@ static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree,
btrfs_backref_free_node(tree, node);
}
void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
struct btrfs_backref_node *node);
#endif

View File

@ -153,9 +153,6 @@ struct reloc_control {
#define MOVE_DATA_EXTENTS 0
#define UPDATE_DATA_PTRS 1
static void remove_backref_node(struct btrfs_backref_cache *cache,
struct btrfs_backref_node *node);
static void mark_block_processed(struct reloc_control *rc,
struct btrfs_backref_node *node)
{
@ -186,13 +183,13 @@ static void backref_cache_cleanup(struct btrfs_backref_cache *cache)
while (!list_empty(&cache->detached)) {
node = list_entry(cache->detached.next,
struct btrfs_backref_node, list);
remove_backref_node(cache, node);
btrfs_backref_cleanup_node(cache, node);
}
while (!list_empty(&cache->leaves)) {
node = list_entry(cache->leaves.next,
struct btrfs_backref_node, lower);
remove_backref_node(cache, node);
btrfs_backref_cleanup_node(cache, node);
}
cache->last_trans = 0;
@ -268,46 +265,6 @@ static struct btrfs_backref_node *walk_down_backref(
*index = 0;
return NULL;
}
/*
* remove a backref node from the backref cache
*/
static void remove_backref_node(struct btrfs_backref_cache *cache,
struct btrfs_backref_node *node)
{
struct btrfs_backref_node *upper;
struct btrfs_backref_edge *edge;
if (!node)
return;
BUG_ON(!node->lowest && !node->detached);
while (!list_empty(&node->upper)) {
edge = list_entry(node->upper.next, struct btrfs_backref_edge,
list[LOWER]);
upper = edge->node[UPPER];
list_del(&edge->list[LOWER]);
list_del(&edge->list[UPPER]);
btrfs_backref_free_edge(cache, edge);
if (RB_EMPTY_NODE(&upper->rb_node)) {
BUG_ON(!list_empty(&node->upper));
btrfs_backref_drop_node(cache, node);
node = upper;
node->lowest = 1;
continue;
}
/*
* add the node to leaf node list if no other
* child block cached.
*/
if (list_empty(&upper->lower)) {
list_add_tail(&upper->lower, &cache->leaves);
upper->lowest = 1;
}
}
btrfs_backref_drop_node(cache, node);
}
static void update_backref_node(struct btrfs_backref_cache *cache,
struct btrfs_backref_node *node, u64 bytenr)
@ -345,7 +302,7 @@ static int update_backref_cache(struct btrfs_trans_handle *trans,
while (!list_empty(&cache->detached)) {
node = list_entry(cache->detached.next,
struct btrfs_backref_node, list);
remove_backref_node(cache, node);
btrfs_backref_cleanup_node(cache, node);
}
while (!list_empty(&cache->changed)) {
@ -1120,7 +1077,7 @@ out:
btrfs_backref_free_node(cache, lower);
}
remove_backref_node(cache, node);
btrfs_backref_cleanup_node(cache, node);
ASSERT(list_empty(&cache->useless_node) &&
list_empty(&cache->pending_edge));
return ERR_PTR(err);
@ -3103,7 +3060,7 @@ static int relocate_tree_block(struct btrfs_trans_handle *trans,
}
out:
if (ret || node->level == 0 || node->cowonly)
remove_backref_node(&rc->backref_cache, node);
btrfs_backref_cleanup_node(&rc->backref_cache, node);
return ret;
}