[PATCH 11/40] btrfs: relocation: Specify essential members for alloc_backref_node()

Qu Wenruo
2020-03-23T10:25:03Z

Bytenr and level are essential parameters for backref_node, thus it
makes sense to initial them at alloc time.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/relocation.c | 39 +++++++++++++++++++--------------------
1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index d3d46590a733..ad5cca49a6e3 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -338,18 +338,23 @@ static void backref_cache_cleanup(struct backref_cache *cache)
ASSERT(!cache->nr_edges);
}

-static struct backref_node *alloc_backref_node(struct backref_cache *cache)
+static struct backref_node *alloc_backref_node(struct backref_cache *cache,
+ u64 bytenr, int level)
{
struct backref_node *node;

+ ASSERT(level >= 0 && level < BTRFS_MAX_LEVEL);
node = kzalloc(sizeof(*node), GFP_NOFS);
- if (node) {
- INIT_LIST_HEAD(&node->list);
- INIT_LIST_HEAD(&node->upper);
- INIT_LIST_HEAD(&node->lower);
- RB_CLEAR_NODE(&node->rb_node);
- cache->nr_nodes++;
- }
+ if (!node)
+ return node;
+ INIT_LIST_HEAD(&node->list);
+ INIT_LIST_HEAD(&node->upper);
+ INIT_LIST_HEAD(&node->lower);
+ RB_CLEAR_NODE(&node->rb_node);
+ cache->nr_nodes++;
+
+ node->level = level;
+ node->bytenr = bytenr;
return node;
}

@@ -774,13 +779,12 @@ static int handle_direct_tree_backref(struct backref_cache *cache,
rb_node = tree_search(&cache->rb_root, ref_key->offset);
if (!rb_node) {
/* Parent node not yet cached */
- upper = alloc_backref_node(cache);
+ upper = alloc_backref_node(cache, ref_key->offset,
+ cur->level + 1);
if (!upper) {
free_backref_edge(cache, edge);
return -ENOMEM;
}
- upper->bytenr = ref_key->offset;
- upper->level = cur->level + 1;

/*
* backrefs for the upper level block isn't
@@ -897,16 +901,15 @@ static int handle_indirect_tree_backref(struct backref_cache *cache,
eb = path->nodes[level];
rb_node = tree_search(&cache->rb_root, eb->start);
if (!rb_node) {
- upper = alloc_backref_node(cache);
+ upper = alloc_backref_node(cache, eb->start,
+ lower->level + 1);
if (!upper) {
btrfs_put_root(root);
free_backref_edge(cache, edge);
ret = -ENOMEM;
goto out;
}
- upper->bytenr = eb->start;
upper->owner = btrfs_header_owner(eb);
- upper->level = lower->level + 1;
if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
upper->cowonly = 1;

@@ -997,14 +1000,12 @@ struct backref_node *build_backref_tree(struct reloc_control *rc,
}
path->reada = READA_FORWARD;

- node = alloc_backref_node(cache);
+ node = alloc_backref_node(cache, bytenr, level);
if (!node) {
err = -ENOMEM;
goto out;
}

- node->bytenr = bytenr;
- node->level = level;
node->lowest = 1;
cur = node;
again:
@@ -1347,12 +1348,10 @@ static int clone_backref_node(struct btrfs_trans_handle *trans,
if (!node)
return 0;

- new_node = alloc_backref_node(cache);
+ new_node = alloc_backref_node(cache, dest->node->start, node->level);
if (!new_node)
return -ENOMEM;

- new_node->bytenr = dest->node->start;
- new_node->level = node->level;
new_node->lowest = node->lowest;
new_node->checked = 1;
new_node->root = btrfs_grab_root(dest);
--
2.25.2