When we split an extent state there's no need to start the rbtree search
from the root node - we can start it from the original extent state node,
since we would end up in its subtree if we do the search starting at the
root node anyway.
Signed-off-by: Filipe David Borba Manana <fdmanana@xxxxxxxxx>
---
V2: Made the intention more clear, that it works only if the tree is not
empty (which is always the case when spliting extent states).
fs/btrfs/extent_io.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index fbe501d..eb465e9 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -229,12 +229,14 @@ void free_extent_state(struct extent_state *state)
}
}
-static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
+static struct rb_node *tree_insert(struct rb_root *root,
+ struct rb_node *search_start,
+ u64 offset,
struct rb_node *node,
struct rb_node ***p_in,
struct rb_node **parent_in)
{
- struct rb_node **p = &root->rb_node;
+ struct rb_node **p;
struct rb_node *parent = NULL;
struct tree_entry *entry;
@@ -244,6 +246,7 @@ static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
goto do_insert;
}
+ p = search_start ? &search_start : &root->rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct tree_entry, rb_node);
@@ -430,7 +433,7 @@ static int insert_state(struct extent_io_tree *tree,
set_state_bits(tree, state, bits);
- node = tree_insert(&tree->state, end, &state->rb_node, p, parent);
+ node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
if (node) {
struct extent_state *found;
found = rb_entry(node, struct extent_state, rb_node);
@@ -477,8 +480,8 @@ static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
prealloc->state = orig->state;
orig->start = split;
- node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node,
- NULL, NULL);
+ node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
+ &prealloc->rb_node, NULL, NULL);
if (node) {
free_extent_state(prealloc);
return -EEXIST;
--
1.7.9.5
--
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