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-rw-r--r--fs/btrfs/delayed-ref.c163
1 files changed, 128 insertions, 35 deletions
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index da7419e..ae94117 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -38,17 +38,14 @@
static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2,
struct btrfs_delayed_tree_ref *ref1)
{
- if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
- if (ref1->root < ref2->root)
- return -1;
- if (ref1->root > ref2->root)
- return 1;
- } else {
- if (ref1->parent < ref2->parent)
- return -1;
- if (ref1->parent > ref2->parent)
- return 1;
- }
+ if (ref1->root < ref2->root)
+ return -1;
+ if (ref1->root > ref2->root)
+ return 1;
+ if (ref1->parent < ref2->parent)
+ return -1;
+ if (ref1->parent > ref2->parent)
+ return 1;
return 0;
}
@@ -85,7 +82,8 @@ static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
* type of the delayed backrefs and content of delayed backrefs.
*/
static int comp_entry(struct btrfs_delayed_ref_node *ref2,
- struct btrfs_delayed_ref_node *ref1)
+ struct btrfs_delayed_ref_node *ref1,
+ bool compare_seq)
{
if (ref1->bytenr < ref2->bytenr)
return -1;
@@ -102,10 +100,12 @@ static int comp_entry(struct btrfs_delayed_ref_node *ref2,
if (ref1->type > ref2->type)
return 1;
/* merging of sequenced refs is not allowed */
- if (ref1->seq < ref2->seq)
- return -1;
- if (ref1->seq > ref2->seq)
- return 1;
+ if (compare_seq) {
+ if (ref1->seq < ref2->seq)
+ return -1;
+ if (ref1->seq > ref2->seq)
+ return 1;
+ }
if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) {
return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2),
@@ -139,7 +139,7 @@ static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
rb_node);
- cmp = comp_entry(entry, ins);
+ cmp = comp_entry(entry, ins, 1);
if (cmp < 0)
p = &(*p)->rb_left;
else if (cmp > 0)
@@ -233,6 +233,114 @@ int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
return 0;
}
+static void inline drop_delayed_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_delayed_ref_root *delayed_refs,
+ struct btrfs_delayed_ref_node *ref)
+{
+ rb_erase(&ref->rb_node, &delayed_refs->root);
+ ref->in_tree = 0;
+ btrfs_put_delayed_ref(ref);
+ delayed_refs->num_entries--;
+ if (trans->delayed_ref_updates)
+ trans->delayed_ref_updates--;
+}
+
+static int merge_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_delayed_ref_root *delayed_refs,
+ struct btrfs_delayed_ref_node *ref, u64 seq)
+{
+ struct rb_node *node;
+ int merged = 0;
+ int mod = 0;
+ int done = 0;
+
+ node = rb_prev(&ref->rb_node);
+ while (node) {
+ struct btrfs_delayed_ref_node *next;
+
+ next = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
+ node = rb_prev(node);
+ if (next->bytenr != ref->bytenr)
+ break;
+ if (seq && next->seq >= seq)
+ break;
+ if (comp_entry(ref, next, 0))
+ continue;
+
+ if (ref->action == next->action) {
+ mod = next->ref_mod;
+ } else {
+ if (ref->ref_mod < next->ref_mod) {
+ struct btrfs_delayed_ref_node *tmp;
+
+ tmp = ref;
+ ref = next;
+ next = tmp;
+ done = 1;
+ }
+ mod = -next->ref_mod;
+ }
+
+ merged++;
+ drop_delayed_ref(trans, delayed_refs, next);
+ ref->ref_mod += mod;
+ if (ref->ref_mod == 0) {
+ drop_delayed_ref(trans, delayed_refs, ref);
+ break;
+ } else {
+ /*
+ * You can't have multiples of the same ref on a tree
+ * block.
+ */
+ WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
+ ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
+ }
+
+ if (done)
+ break;
+ node = rb_prev(&ref->rb_node);
+ }
+
+ return merged;
+}
+
+void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info,
+ struct btrfs_delayed_ref_root *delayed_refs,
+ struct btrfs_delayed_ref_head *head)
+{
+ struct rb_node *node;
+ u64 seq = 0;
+
+ spin_lock(&fs_info->tree_mod_seq_lock);
+ if (!list_empty(&fs_info->tree_mod_seq_list)) {
+ struct seq_list *elem;
+
+ elem = list_first_entry(&fs_info->tree_mod_seq_list,
+ struct seq_list, list);
+ seq = elem->seq;
+ }
+ spin_unlock(&fs_info->tree_mod_seq_lock);
+
+ node = rb_prev(&head->node.rb_node);
+ while (node) {
+ struct btrfs_delayed_ref_node *ref;
+
+ ref = rb_entry(node, struct btrfs_delayed_ref_node,
+ rb_node);
+ if (ref->bytenr != head->node.bytenr)
+ break;
+
+ /* We can't merge refs that are outside of our seq count */
+ if (seq && ref->seq >= seq)
+ break;
+ if (merge_ref(trans, delayed_refs, ref, seq))
+ node = rb_prev(&head->node.rb_node);
+ else
+ node = rb_prev(node);
+ }
+}
+
int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
struct btrfs_delayed_ref_root *delayed_refs,
u64 seq)
@@ -336,18 +444,11 @@ update_existing_ref(struct btrfs_trans_handle *trans,
* every changing the extent allocation tree.
*/
existing->ref_mod--;
- if (existing->ref_mod == 0) {
- rb_erase(&existing->rb_node,
- &delayed_refs->root);
- existing->in_tree = 0;
- btrfs_put_delayed_ref(existing);
- delayed_refs->num_entries--;
- if (trans->delayed_ref_updates)
- trans->delayed_ref_updates--;
- } else {
+ if (existing->ref_mod == 0)
+ drop_delayed_ref(trans, delayed_refs, existing);
+ else
WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
- }
} else {
WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
@@ -662,9 +763,6 @@ int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr,
num_bytes, parent, ref_root, level, action,
for_cow);
- if (!need_ref_seq(for_cow, ref_root) &&
- waitqueue_active(&fs_info->tree_mod_seq_wait))
- wake_up(&fs_info->tree_mod_seq_wait);
spin_unlock(&delayed_refs->lock);
if (need_ref_seq(for_cow, ref_root))
btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
@@ -713,9 +811,6 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
add_delayed_data_ref(fs_info, trans, &ref->node, bytenr,
num_bytes, parent, ref_root, owner, offset,
action, for_cow);
- if (!need_ref_seq(for_cow, ref_root) &&
- waitqueue_active(&fs_info->tree_mod_seq_wait))
- wake_up(&fs_info->tree_mod_seq_wait);
spin_unlock(&delayed_refs->lock);
if (need_ref_seq(for_cow, ref_root))
btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
@@ -744,8 +839,6 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
extent_op->is_data);
- if (waitqueue_active(&fs_info->tree_mod_seq_wait))
- wake_up(&fs_info->tree_mod_seq_wait);
spin_unlock(&delayed_refs->lock);
return 0;
}
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