1 files changed, 106 insertions, 47 deletions

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 125cf76fcd08..66e4f29505a3 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -101,6 +101,11 @@ static int comp_entry(struct btrfs_delayed_ref_node *ref2,
                 return -1;
         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 (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),
@@ -150,16 +155,22 @@ static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
 
 /*
  * find an head entry based on bytenr. This returns the delayed ref
- * head if it was able to find one, or NULL if nothing was in that spot
+ * head if it was able to find one, or NULL if nothing was in that spot.
+ * If return_bigger is given, the next bigger entry is returned if no exact
+ * match is found.
  */
 static struct btrfs_delayed_ref_node *find_ref_head(struct rb_root *root,
                                   u64 bytenr,
-                                  struct btrfs_delayed_ref_node **last)
+                                  struct btrfs_delayed_ref_node **last,
+                                  int return_bigger)
 {
-        struct rb_node *n = root->rb_node;
+        struct rb_node *n;
         struct btrfs_delayed_ref_node *entry;
-        int cmp;
+        int cmp = 0;
 
+again:
+        n = root->rb_node;
+        entry = NULL;
         while (n) {
                 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
                 WARN_ON(!entry->in_tree);
@@ -182,6 +193,19 @@ static struct btrfs_delayed_ref_node *find_ref_head(struct rb_root *root,
                 else
                         return entry;
         }
+        if (entry && return_bigger) {
+                if (cmp > 0) {
+                        n = rb_next(&entry->rb_node);
+                        if (!n)
+                                n = rb_first(root);
+                        entry = rb_entry(n, struct btrfs_delayed_ref_node,
+                                         rb_node);
+                        bytenr = entry->bytenr;
+                        return_bigger = 0;
+                        goto again;
+                }
+                return entry;
+        }
         return NULL;
 }
 
@@ -209,6 +233,24 @@ int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
         return 0;
 }
 
+int btrfs_check_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs,
+                            u64 seq)
+{
+        struct seq_list *elem;
+
+        assert_spin_locked(&delayed_refs->lock);
+        if (list_empty(&delayed_refs->seq_head))
+                return 0;
+
+        elem = list_first_entry(&delayed_refs->seq_head, struct seq_list, list);
+        if (seq >= elem->seq) {
+                pr_debug("holding back delayed_ref %llu, lowest is %llu (%p)\n",
+                         seq, elem->seq, delayed_refs);
+                return 1;
+        }
+        return 0;
+}
+
 int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
                            struct list_head *cluster, u64 start)
 {
@@ -223,20 +265,8 @@ int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
                 node = rb_first(&delayed_refs->root);
         } else {
                 ref = NULL;
-                find_ref_head(&delayed_refs->root, start, &ref);
+                find_ref_head(&delayed_refs->root, start + 1, &ref, 1);
                 if (ref) {
-                        struct btrfs_delayed_ref_node *tmp;
-
-                        node = rb_prev(&ref->rb_node);
-                        while (node) {
-                                tmp = rb_entry(node,
-                                               struct btrfs_delayed_ref_node,
-                                               rb_node);
-                                if (tmp->bytenr < start)
-                                        break;
-                                ref = tmp;
-                                node = rb_prev(&ref->rb_node);
-                        }
                         node = &ref->rb_node;
                 } else
                         node = rb_first(&delayed_refs->root);
@@ -390,7 +420,8 @@ update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
  * this does all the dirty work in terms of maintaining the correct
  * overall modification count.
  */
-static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans,
+static noinline int add_delayed_ref_head(struct btrfs_fs_info *fs_info,
+                                        struct btrfs_trans_handle *trans,
                                         struct btrfs_delayed_ref_node *ref,
                                         u64 bytenr, u64 num_bytes,
                                         int action, int is_data)
@@ -437,6 +468,7 @@ static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans,
         ref->action  = 0;
         ref->is_head = 1;
         ref->in_tree = 1;
+        ref->seq = 0;
 
         head_ref = btrfs_delayed_node_to_head(ref);
         head_ref->must_insert_reserved = must_insert_reserved;
@@ -468,14 +500,17 @@ static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans,
 /*
  * helper to insert a delayed tree ref into the rbtree.
  */
-static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans,
+static noinline int add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
+                                         struct btrfs_trans_handle *trans,
                                          struct btrfs_delayed_ref_node *ref,
                                          u64 bytenr, u64 num_bytes, u64 parent,
-                                         u64 ref_root, int level, int action)
+                                         u64 ref_root, int level, int action,
+                                         int for_cow)
 {
         struct btrfs_delayed_ref_node *existing;
         struct btrfs_delayed_tree_ref *full_ref;
         struct btrfs_delayed_ref_root *delayed_refs;
+        u64 seq = 0;
 
         if (action == BTRFS_ADD_DELAYED_EXTENT)
                 action = BTRFS_ADD_DELAYED_REF;
@@ -491,14 +526,17 @@ static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans,
         ref->is_head = 0;
         ref->in_tree = 1;
 
+        if (need_ref_seq(for_cow, ref_root))
+                seq = inc_delayed_seq(delayed_refs);
+        ref->seq = seq;
+
         full_ref = btrfs_delayed_node_to_tree_ref(ref);
-        if (parent) {
-                full_ref->parent = parent;
+        full_ref->parent = parent;
+        full_ref->root = ref_root;
+        if (parent)
                 ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
-        } else {
-                full_ref->root = ref_root;
+        else
                 ref->type = BTRFS_TREE_BLOCK_REF_KEY;
-        }
         full_ref->level = level;
 
         trace_btrfs_delayed_tree_ref(ref, full_ref, action);
@@ -522,15 +560,17 @@ static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans,
 /*
  * helper to insert a delayed data ref into the rbtree.
  */
-static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans,
+static noinline int add_delayed_data_ref(struct btrfs_fs_info *fs_info,
+                                         struct btrfs_trans_handle *trans,
                                          struct btrfs_delayed_ref_node *ref,
                                          u64 bytenr, u64 num_bytes, u64 parent,
                                          u64 ref_root, u64 owner, u64 offset,
-                                         int action)
+                                         int action, int for_cow)
 {
         struct btrfs_delayed_ref_node *existing;
         struct btrfs_delayed_data_ref *full_ref;
         struct btrfs_delayed_ref_root *delayed_refs;
+        u64 seq = 0;
 
         if (action == BTRFS_ADD_DELAYED_EXTENT)
                 action = BTRFS_ADD_DELAYED_REF;
@@ -546,14 +586,18 @@ static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans,
         ref->is_head = 0;
         ref->in_tree = 1;
 
+        if (need_ref_seq(for_cow, ref_root))
+                seq = inc_delayed_seq(delayed_refs);
+        ref->seq = seq;
+
         full_ref = btrfs_delayed_node_to_data_ref(ref);
-        if (parent) {
-                full_ref->parent = parent;
+        full_ref->parent = parent;
+        full_ref->root = ref_root;
+        if (parent)
                 ref->type = BTRFS_SHARED_DATA_REF_KEY;
-        } else {
-                full_ref->root = ref_root;
+        else
                 ref->type = BTRFS_EXTENT_DATA_REF_KEY;
-        }
+
         full_ref->objectid = owner;
         full_ref->offset = offset;
 
@@ -580,10 +624,12 @@ static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans,
  * to make sure the delayed ref is eventually processed before this
  * transaction commits.
  */
-int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
+int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
+                               struct btrfs_trans_handle *trans,
                                u64 bytenr, u64 num_bytes, u64 parent,
                                u64 ref_root,  int level, int action,
-                               struct btrfs_delayed_extent_op *extent_op)
+                               struct btrfs_delayed_extent_op *extent_op,
+                               int for_cow)
 {
         struct btrfs_delayed_tree_ref *ref;
         struct btrfs_delayed_ref_head *head_ref;
@@ -610,13 +656,17 @@ int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
          * insert both the head node and the new ref without dropping
          * the spin lock
          */
-        ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes,
-                                   action, 0);
+        ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
+                                   num_bytes, action, 0);
         BUG_ON(ret);
 
-        ret = add_delayed_tree_ref(trans, &ref->node, bytenr, num_bytes,
-                                   parent, ref_root, level, action);
+        ret = add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr,
+                                   num_bytes, parent, ref_root, level, action,
+                                   for_cow);
         BUG_ON(ret);
+        if (!need_ref_seq(for_cow, ref_root) &&
+            waitqueue_active(&delayed_refs->seq_wait))
+                wake_up(&delayed_refs->seq_wait);
         spin_unlock(&delayed_refs->lock);
         return 0;
 }
@@ -624,11 +674,13 @@ int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
 /*
  * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
  */
-int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
+int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
+                               struct btrfs_trans_handle *trans,
                                u64 bytenr, u64 num_bytes,
                                u64 parent, u64 ref_root,
                                u64 owner, u64 offset, int action,
-                               struct btrfs_delayed_extent_op *extent_op)
+                               struct btrfs_delayed_extent_op *extent_op,
+                               int for_cow)
 {
         struct btrfs_delayed_data_ref *ref;
         struct btrfs_delayed_ref_head *head_ref;
@@ -655,18 +707,23 @@ int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
          * insert both the head node and the new ref without dropping
          * the spin lock
          */
-        ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes,
-                                   action, 1);
+        ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
+                                   num_bytes, action, 1);
         BUG_ON(ret);
 
-        ret = add_delayed_data_ref(trans, &ref->node, bytenr, num_bytes,
-                                   parent, ref_root, owner, offset, action);
+        ret = add_delayed_data_ref(fs_info, trans, &ref->node, bytenr,
+                                   num_bytes, parent, ref_root, owner, offset,
+                                   action, for_cow);
         BUG_ON(ret);
+        if (!need_ref_seq(for_cow, ref_root) &&
+            waitqueue_active(&delayed_refs->seq_wait))
+                wake_up(&delayed_refs->seq_wait);
         spin_unlock(&delayed_refs->lock);
         return 0;
 }
 
-int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
+int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
+                                struct btrfs_trans_handle *trans,
                                 u64 bytenr, u64 num_bytes,
                                 struct btrfs_delayed_extent_op *extent_op)
 {
@@ -683,11 +740,13 @@ int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
         delayed_refs = &trans->transaction->delayed_refs;
         spin_lock(&delayed_refs->lock);
 
-        ret = add_delayed_ref_head(trans, &head_ref->node, bytenr,
+        ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
                                    num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
                                    extent_op->is_data);
         BUG_ON(ret);
 
+        if (waitqueue_active(&delayed_refs->seq_wait))
+                wake_up(&delayed_refs->seq_wait);
         spin_unlock(&delayed_refs->lock);
         return 0;
 }
@@ -704,7 +763,7 @@ btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
         struct btrfs_delayed_ref_root *delayed_refs;
 
         delayed_refs = &trans->transaction->delayed_refs;
-        ref = find_ref_head(&delayed_refs->root, bytenr, NULL);
+        ref = find_ref_head(&delayed_refs->root, bytenr, NULL, 0);
         if (ref)
                 return btrfs_delayed_node_to_head(ref);
         return NULL;