4 files changed, 186 insertions, 44 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b7e2c1c1ef36..be91397f4e92 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1259,11 +1259,19 @@ struct btrfs_block_group_cache {
         spinlock_t lock;
         u64 pinned;
         u64 reserved;
+        u64 delalloc_bytes;
         u64 bytes_super;
         u64 flags;
         u64 sectorsize;
         u64 cache_generation;
 
+        /*
+         * It is just used for the delayed data space allocation because
+         * only the data space allocation and the relative metadata update
+         * can be done cross the transaction.
+         */
+        struct rw_semaphore data_rwsem;
+
         /* for raid56, this is a full stripe, without parity */
         unsigned long full_stripe_len;
 
@@ -3316,7 +3324,7 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
                                    struct btrfs_key *ins);
 int btrfs_reserve_extent(struct btrfs_root *root, u64 num_bytes,
                          u64 min_alloc_size, u64 empty_size, u64 hint_byte,
-                         struct btrfs_key *ins, int is_data);
+                         struct btrfs_key *ins, int is_data, int delalloc);
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                   struct extent_buffer *buf, int full_backref, int no_quota);
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -3330,7 +3338,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
                       u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
                       u64 owner, u64 offset, int no_quota);
 
-int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len);
+int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len,
+                               int delalloc);
 int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
                                        u64 start, u64 len);
 void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fafb3e53ecde..99c253918208 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -105,7 +105,8 @@ static int find_next_key(struct btrfs_path *path, int level,
 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
                             int dump_block_groups);
 static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
-                                       u64 num_bytes, int reserve);
+                                       u64 num_bytes, int reserve,
+                                       int delalloc);
 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
                                u64 num_bytes);
 int btrfs_pin_extent(struct btrfs_root *root,
@@ -3260,7 +3261,8 @@ again:
 
         spin_lock(&block_group->lock);
         if (block_group->cached != BTRFS_CACHE_FINISHED ||
-            !btrfs_test_opt(root, SPACE_CACHE)) {
+            !btrfs_test_opt(root, SPACE_CACHE) ||
+            block_group->delalloc_bytes) {
                 /*
                  * don't bother trying to write stuff out _if_
                  * a) we're not cached,
@@ -5613,6 +5615,7 @@ int btrfs_exclude_logged_extents(struct btrfs_root *log,
  * @cache:      The cache we are manipulating
  * @num_bytes:  The number of bytes in question
  * @reserve:    One of the reservation enums
+ * @delalloc:   The blocks are allocated for the delalloc write
  *
  * This is called by the allocator when it reserves space, or by somebody who is
  * freeing space that was never actually used on disk.  For example if you
@@ -5631,7 +5634,7 @@ int btrfs_exclude_logged_extents(struct btrfs_root *log,
  * succeeds.
  */
 static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
-                                       u64 num_bytes, int reserve)
+                                       u64 num_bytes, int reserve, int delalloc)
 {
         struct btrfs_space_info *space_info = cache->space_info;
         int ret = 0;
@@ -5650,12 +5653,18 @@ static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
                                                 num_bytes, 0);
                                 space_info->bytes_may_use -= num_bytes;
                         }
+
+                        if (delalloc)
+                                cache->delalloc_bytes += num_bytes;
                 }
         } else {
                 if (cache->ro)
                         space_info->bytes_readonly += num_bytes;
                 cache->reserved -= num_bytes;
                 space_info->bytes_reserved -= num_bytes;
+
+                if (delalloc)
+                        cache->delalloc_bytes -= num_bytes;
         }
         spin_unlock(&cache->lock);
         spin_unlock(&space_info->lock);
@@ -6206,7 +6215,7 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
                 WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
 
                 btrfs_add_free_space(cache, buf->start, buf->len);
-                btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE);
+                btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE, 0);
                 trace_btrfs_reserved_extent_free(root, buf->start, buf->len);
                 pin = 0;
         }
@@ -6365,6 +6374,70 @@ enum btrfs_loop_type {
         LOOP_NO_EMPTY_SIZE = 3,
 };
 
+static inline void
+btrfs_lock_block_group(struct btrfs_block_group_cache *cache,
+                       int delalloc)
+{
+        if (delalloc)
+                down_read(&cache->data_rwsem);
+}
+
+static inline void
+btrfs_grab_block_group(struct btrfs_block_group_cache *cache,
+                       int delalloc)
+{
+        btrfs_get_block_group(cache);
+        if (delalloc)
+                down_read(&cache->data_rwsem);
+}
+
+static struct btrfs_block_group_cache *
+btrfs_lock_cluster(struct btrfs_block_group_cache *block_group,
+                   struct btrfs_free_cluster *cluster,
+                   int delalloc)
+{
+        struct btrfs_block_group_cache *used_bg;
+        bool locked = false;
+again:
+        spin_lock(&cluster->refill_lock);
+        if (locked) {
+                if (used_bg == cluster->block_group)
+                        return used_bg;
+
+                up_read(&used_bg->data_rwsem);
+                btrfs_put_block_group(used_bg);
+        }
+
+        used_bg = cluster->block_group;
+        if (!used_bg)
+                return NULL;
+
+        if (used_bg == block_group)
+                return used_bg;
+
+        btrfs_get_block_group(used_bg);
+
+        if (!delalloc)
+                return used_bg;
+
+        if (down_read_trylock(&used_bg->data_rwsem))
+                return used_bg;
+
+        spin_unlock(&cluster->refill_lock);
+        down_read(&used_bg->data_rwsem);
+        locked = true;
+        goto again;
+}