Btrfs: add a delalloc mutex to inodes for delalloc reservations
[firefly-linux-kernel-4.4.55.git] / fs / btrfs / extent-tree.c
index 352083ad233ca2a18b8c3817d3f3a5644000bf76..e0ad5f0f895ea789ef8a7fe2b58f3ce3c523cabd 100644 (file)
@@ -1871,20 +1871,24 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
                         struct btrfs_root *root,
                         u64 bytenr, u64 num_bytes, u64 parent,
-                        u64 root_objectid, u64 owner, u64 offset)
+                        u64 root_objectid, u64 owner, u64 offset, int for_cow)
 {
        int ret;
+       struct btrfs_fs_info *fs_info = root->fs_info;
+
        BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
               root_objectid == BTRFS_TREE_LOG_OBJECTID);
 
        if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-               ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
+               ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
+                                       num_bytes,
                                        parent, root_objectid, (int)owner,
-                                       BTRFS_ADD_DELAYED_REF, NULL);
+                                       BTRFS_ADD_DELAYED_REF, NULL, for_cow);
        } else {
-               ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
+               ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
+                                       num_bytes,
                                        parent, root_objectid, owner, offset,
-                                       BTRFS_ADD_DELAYED_REF, NULL);
+                                       BTRFS_ADD_DELAYED_REF, NULL, for_cow);
        }
        return ret;
 }
@@ -2231,6 +2235,28 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                        }
                }
 
+               /*
+                * locked_ref is the head node, so we have to go one
+                * node back for any delayed ref updates
+                */
+               ref = select_delayed_ref(locked_ref);
+
+               if (ref && ref->seq &&
+                   btrfs_check_delayed_seq(delayed_refs, ref->seq)) {
+                       /*
+                        * there are still refs with lower seq numbers in the
+                        * process of being added. Don't run this ref yet.
+                        */
+                       list_del_init(&locked_ref->cluster);
+                       mutex_unlock(&locked_ref->mutex);
+                       locked_ref = NULL;
+                       delayed_refs->num_heads_ready++;
+                       spin_unlock(&delayed_refs->lock);
+                       cond_resched();
+                       spin_lock(&delayed_refs->lock);
+                       continue;
+               }
+
                /*
                 * record the must insert reserved flag before we
                 * drop the spin lock.
@@ -2241,11 +2267,6 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                extent_op = locked_ref->extent_op;
                locked_ref->extent_op = NULL;
 
-               /*
-                * locked_ref is the head node, so we have to go one
-                * node back for any delayed ref updates
-                */
-               ref = select_delayed_ref(locked_ref);
                if (!ref) {
                        /* All delayed refs have been processed, Go ahead
                         * and send the head node to run_one_delayed_ref,
@@ -2276,7 +2297,12 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                ref->in_tree = 0;
                rb_erase(&ref->rb_node, &delayed_refs->root);
                delayed_refs->num_entries--;
-
+               /*
+                * we modified num_entries, but as we're currently running
+                * delayed refs, skip
+                *     wake_up(&delayed_refs->seq_wait);
+                * here.
+                */
                spin_unlock(&delayed_refs->lock);
 
                ret = run_one_delayed_ref(trans, root, ref, extent_op,
@@ -2297,6 +2323,23 @@ next:
        return count;
 }
 
+
+static void wait_for_more_refs(struct btrfs_delayed_ref_root *delayed_refs,
+                       unsigned long num_refs)
+{
+       struct list_head *first_seq = delayed_refs->seq_head.next;
+
+       spin_unlock(&delayed_refs->lock);
+       pr_debug("waiting for more refs (num %ld, first %p)\n",
+                num_refs, first_seq);
+       wait_event(delayed_refs->seq_wait,
+                  num_refs != delayed_refs->num_entries ||
+                  delayed_refs->seq_head.next != first_seq);
+       pr_debug("done waiting for more refs (num %ld, first %p)\n",
+                delayed_refs->num_entries, delayed_refs->seq_head.next);
+       spin_lock(&delayed_refs->lock);
+}
+
 /*
  * this starts processing the delayed reference count updates and
  * extent insertions we have queued up so far.  count can be
@@ -2312,8 +2355,11 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
        struct btrfs_delayed_ref_node *ref;
        struct list_head cluster;
        int ret;
+       u64 delayed_start;
        int run_all = count == (unsigned long)-1;
        int run_most = 0;
+       unsigned long num_refs = 0;
+       int consider_waiting;
 
        if (root == root->fs_info->extent_root)
                root = root->fs_info->tree_root;
@@ -2325,6 +2371,7 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
        delayed_refs = &trans->transaction->delayed_refs;
        INIT_LIST_HEAD(&cluster);
 again:
+       consider_waiting = 0;
        spin_lock(&delayed_refs->lock);
        if (count == 0) {
                count = delayed_refs->num_entries * 2;
@@ -2341,11 +2388,35 @@ again:
                 * of refs to process starting at the first one we are able to
                 * lock
                 */
+               delayed_start = delayed_refs->run_delayed_start;
                ret = btrfs_find_ref_cluster(trans, &cluster,
                                             delayed_refs->run_delayed_start);
                if (ret)
                        break;
 
+               if (delayed_start >= delayed_refs->run_delayed_start) {
+                       if (consider_waiting == 0) {
+                               /*
+                                * btrfs_find_ref_cluster looped. let's do one
+                                * more cycle. if we don't run any delayed ref
+                                * during that cycle (because we can't because
+                                * all of them are blocked) and if the number of
+                                * refs doesn't change, we avoid busy waiting.
+                                */
+                               consider_waiting = 1;
+                               num_refs = delayed_refs->num_entries;
+                       } else {
+                               wait_for_more_refs(delayed_refs, num_refs);
+                               /*
+                                * after waiting, things have changed. we
+                                * dropped the lock and someone else might have
+                                * run some refs, built new clusters and so on.
+                                * therefore, we restart staleness detection.
+                                */
+                               consider_waiting = 0;
+                       }
+               }
+
                ret = run_clustered_refs(trans, root, &cluster);
                BUG_ON(ret < 0);
 
@@ -2353,6 +2424,11 @@ again:
 
                if (count == 0)
                        break;
+
+               if (ret || delayed_refs->run_delayed_start == 0) {
+                       /* refs were run, let's reset staleness detection */
+                       consider_waiting = 0;
+               }
        }
 
        if (run_all) {
@@ -2410,7 +2486,8 @@ int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
        extent_op->update_key = 0;
        extent_op->is_data = is_data ? 1 : 0;
 
-       ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
+       ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
+                                         num_bytes, extent_op);
        if (ret)
                kfree(extent_op);
        return ret;
@@ -2595,7 +2672,7 @@ out:
 static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           struct extent_buffer *buf,
-                          int full_backref, int inc)
+                          int full_backref, int inc, int for_cow)
 {
        u64 bytenr;
        u64 num_bytes;
@@ -2608,7 +2685,7 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
        int level;
        int ret = 0;
        int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
-                           u64, u64, u64, u64, u64, u64);
+                           u64, u64, u64, u64, u64, u64, int);
 
        ref_root = btrfs_header_owner(buf);
        nritems = btrfs_header_nritems(buf);
@@ -2645,14 +2722,15 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
                        key.offset -= btrfs_file_extent_offset(buf, fi);
                        ret = process_func(trans, root, bytenr, num_bytes,
                                           parent, ref_root, key.objectid,
-                                          key.offset);
+                                          key.offset, for_cow);
                        if (ret)
                                goto fail;
                } else {
                        bytenr = btrfs_node_blockptr(buf, i);
                        num_bytes = btrfs_level_size(root, level - 1);
                        ret = process_func(trans, root, bytenr, num_bytes,
-                                          parent, ref_root, level - 1, 0);
+                                          parent, ref_root, level - 1, 0,
+                                          for_cow);
                        if (ret)
                                goto fail;
                }
@@ -2664,15 +2742,15 @@ fail:
 }
 
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                 struct extent_buffer *buf, int full_backref)
+                 struct extent_buffer *buf, int full_backref, int for_cow)
 {
-       return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
+       return __btrfs_mod_ref(trans, root, buf, full_backref, 1, for_cow);
 }
 
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                 struct extent_buffer *buf, int full_backref)
+                 struct extent_buffer *buf, int full_backref, int for_cow)
 {
-       return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
+       return __btrfs_mod_ref(trans, root, buf, full_backref, 0, for_cow);
 }
 
 static int write_one_cache_group(struct btrfs_trans_handle *trans,
@@ -3232,6 +3310,8 @@ commit_trans:
                return -ENOSPC;
        }
        data_sinfo->bytes_may_use += bytes;
+       trace_btrfs_space_reservation(root->fs_info, "space_info",
+                                     (u64)data_sinfo, bytes, 1);
        spin_unlock(&data_sinfo->lock);
 
        return 0;
@@ -3251,6 +3331,8 @@ void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
        data_sinfo = BTRFS_I(inode)->space_info;
        spin_lock(&data_sinfo->lock);
        data_sinfo->bytes_may_use -= bytes;
+       trace_btrfs_space_reservation(root->fs_info, "space_info",
+                                     (u64)data_sinfo, bytes, 0);
        spin_unlock(&data_sinfo->lock);
 }
 
@@ -3608,6 +3690,10 @@ again:
        if (used <= space_info->total_bytes) {
                if (used + orig_bytes <= space_info->total_bytes) {
                        space_info->bytes_may_use += orig_bytes;
+                       trace_btrfs_space_reservation(root->fs_info,
+                                                     "space_info",
+                                                     (u64)space_info,
+                                                     orig_bytes, 1);
                        ret = 0;
                } else {
                        /*
@@ -3675,6 +3761,10 @@ again:
 
                if (used + num_bytes < space_info->total_bytes + avail) {
                        space_info->bytes_may_use += orig_bytes;
+                       trace_btrfs_space_reservation(root->fs_info,
+                                                     "space_info",
+                                                     (u64)space_info,
+                                                     orig_bytes, 1);
                        ret = 0;
                } else {
                        wait_ordered = true;
@@ -3781,7 +3871,8 @@ static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
        spin_unlock(&block_rsv->lock);
 }
 
-static void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
+static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
+                                   struct btrfs_block_rsv *block_rsv,
                                    struct btrfs_block_rsv *dest, u64 num_bytes)
 {
        struct btrfs_space_info *space_info = block_rsv->space_info;
@@ -3817,6 +3908,9 @@ static void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
                if (num_bytes) {
                        spin_lock(&space_info->lock);
                        space_info->bytes_may_use -= num_bytes;
+                       trace_btrfs_space_reservation(fs_info, "space_info",
+                                                     (u64)space_info,
+                                                     num_bytes, 0);
                        space_info->reservation_progress++;
                        spin_unlock(&space_info->lock);
                }
@@ -3973,7 +4067,8 @@ void btrfs_block_rsv_release(struct btrfs_root *root,
        if (global_rsv->full || global_rsv == block_rsv ||
            block_rsv->space_info != global_rsv->space_info)
                global_rsv = NULL;
-       block_rsv_release_bytes(block_rsv, global_rsv, num_bytes);
+       block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv,
+                               num_bytes);
 }
 
 /*
@@ -4032,11 +4127,15 @@ static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
                num_bytes = sinfo->total_bytes - num_bytes;
                block_rsv->reserved += num_bytes;
                sinfo->bytes_may_use += num_bytes;
+               trace_btrfs_space_reservation(fs_info, "space_info",
+                                             (u64)sinfo, num_bytes, 1);
        }
 
        if (block_rsv->reserved >= block_rsv->size) {
                num_bytes = block_rsv->reserved - block_rsv->size;
                sinfo->bytes_may_use -= num_bytes;
+               trace_btrfs_space_reservation(fs_info, "space_info",
+                                             (u64)sinfo, num_bytes, 0);
                sinfo->reservation_progress++;
                block_rsv->reserved = block_rsv->size;
                block_rsv->full = 1;
@@ -4071,7 +4170,8 @@ static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
 
 static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
 {
-       block_rsv_release_bytes(&fs_info->global_block_rsv, NULL, (u64)-1);
+       block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
+                               (u64)-1);
        WARN_ON(fs_info->delalloc_block_rsv.size > 0);
        WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
        WARN_ON(fs_info->trans_block_rsv.size > 0);
@@ -4088,6 +4188,8 @@ void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
        if (!trans->bytes_reserved)
                return;
 
+       trace_btrfs_space_reservation(root->fs_info, "transaction", (u64)trans,
+                                     trans->bytes_reserved, 0);
        btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
        trans->bytes_reserved = 0;
 }
@@ -4105,6 +4207,8 @@ int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
         * when we are truly done with the orphan item.
         */
        u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+       trace_btrfs_space_reservation(root->fs_info, "orphan",
+                                     btrfs_ino(inode), num_bytes, 1);
        return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
 
@@ -4112,6 +4216,8 @@ void btrfs_orphan_release_metadata(struct inode *inode)
 {
        struct btrfs_root *root = BTRFS_I(inode)->root;
        u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
+       trace_btrfs_space_reservation(root->fs_info, "orphan",
+                                     btrfs_ino(inode), num_bytes, 0);
        btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
 }
 
@@ -4239,12 +4345,11 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
        /* Need to be holding the i_mutex here if we aren't free space cache */
        if (btrfs_is_free_space_inode(root, inode))
                flush = 0;
-       else
-               WARN_ON(!mutex_is_locked(&inode->i_mutex));
 
        if (flush && btrfs_transaction_in_commit(root->fs_info))
                schedule_timeout(1);
 
+       mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
        num_bytes = ALIGN(num_bytes, root->sectorsize);
 
        spin_lock(&BTRFS_I(inode)->lock);
@@ -4292,8 +4397,14 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
                if (dropped)
                        to_free += btrfs_calc_trans_metadata_size(root, dropped);
 
-               if (to_free)
+               if (to_free) {
                        btrfs_block_rsv_release(root, block_rsv, to_free);
+                       trace_btrfs_space_reservation(root->fs_info,
+                                                     "delalloc",
+                                                     btrfs_ino(inode),
+                                                     to_free, 0);
+               }
+               mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
                return ret;
        }
 
@@ -4304,7 +4415,11 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
        }
        BTRFS_I(inode)->reserved_extents += nr_extents;
        spin_unlock(&BTRFS_I(inode)->lock);
+       mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
 
+       if (to_reserve)
+               trace_btrfs_space_reservation(root->fs_info,"delalloc",
+                                             btrfs_ino(inode), to_reserve, 1);
        block_rsv_add_bytes(block_rsv, to_reserve, 1);
 
        return 0;
@@ -4334,6 +4449,8 @@ void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
        if (dropped > 0)
                to_free += btrfs_calc_trans_metadata_size(root, dropped);
 
+       trace_btrfs_space_reservation(root->fs_info, "delalloc",
+                                     btrfs_ino(inode), to_free, 0);
        btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
                                to_free);
 }
@@ -4588,7 +4705,10 @@ static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
                        cache->reserved += num_bytes;
                        space_info->bytes_reserved += num_bytes;
                        if (reserve == RESERVE_ALLOC) {
-                               BUG_ON(space_info->bytes_may_use < num_bytes);
+                               trace_btrfs_space_reservation(cache->fs_info,
+                                                             "space_info",
+                                                             (u64)space_info,
+                                                             num_bytes, 0);
                                space_info->bytes_may_use -= num_bytes;
                        }
                }
@@ -4954,6 +5074,8 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
        rb_erase(&head->node.rb_node, &delayed_refs->root);
 
        delayed_refs->num_entries--;
+       if (waitqueue_active(&delayed_refs->seq_wait))
+               wake_up(&delayed_refs->seq_wait);
 
        /*
         * we don't take a ref on the node because we're removing it from the
@@ -4981,16 +5103,17 @@ out:
 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           struct extent_buffer *buf,
-                          u64 parent, int last_ref)
+                          u64 parent, int last_ref, int for_cow)
 {
        struct btrfs_block_group_cache *cache = NULL;
        int ret;
 
        if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
-               ret = btrfs_add_delayed_tree_ref(trans, buf->start, buf->len,
-                                               parent, root->root_key.objectid,
-                                               btrfs_header_level(buf),
-                                               BTRFS_DROP_DELAYED_REF, NULL);
+               ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
+                                       buf->start, buf->len,
+                                       parent, root->root_key.objectid,
+                                       btrfs_header_level(buf),
+                                       BTRFS_DROP_DELAYED_REF, NULL, for_cow);
                BUG_ON(ret);
        }
 
@@ -5025,12 +5148,12 @@ out:
        btrfs_put_block_group(cache);
 }
 
-int btrfs_free_extent(struct btrfs_trans_handle *trans,
-                     struct btrfs_root *root,
-                     u64 bytenr, u64 num_bytes, u64 parent,
-                     u64 root_objectid, u64 owner, u64 offset)
+int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                     u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
+                     u64 owner, u64 offset, int for_cow)
 {
        int ret;
+       struct btrfs_fs_info *fs_info = root->fs_info;
 
        /*
         * tree log blocks never actually go into the extent allocation
@@ -5042,14 +5165,17 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
                btrfs_pin_extent(root, bytenr, num_bytes, 1);
                ret = 0;
        } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-               ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
+               ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
+                                       num_bytes,
                                        parent, root_objectid, (int)owner,
-                                       BTRFS_DROP_DELAYED_REF, NULL);
+                                       BTRFS_DROP_DELAYED_REF, NULL, for_cow);
                BUG_ON(ret);
        } else {
-               ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
-                                       parent, root_objectid, owner,
-                                       offset, BTRFS_DROP_DELAYED_REF, NULL);
+               ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
+                                               num_bytes,
+                                               parent, root_objectid, owner,
+                                               offset, BTRFS_DROP_DELAYED_REF,
+                                               NULL, for_cow);
                BUG_ON(ret);
        }
        return ret;
@@ -5172,6 +5298,8 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans,
        ins->objectid = 0;
        ins->offset = 0;
 
+       trace_find_free_extent(orig_root, num_bytes, empty_size, data);
+
        space_info = __find_space_info(root->fs_info, data);
        if (!space_info) {
                printk(KERN_ERR "No space info for %llu\n", data);
@@ -5348,6 +5476,8 @@ alloc:
                        if (offset) {
                                /* we have a block, we're done */
                                spin_unlock(&last_ptr->refill_lock);
+                               trace_btrfs_reserve_extent_cluster(root,
+                                       block_group, search_start, num_bytes);
                                goto checks;
                        }
 
@@ -5406,6 +5536,9 @@ refill_cluster:
                                if (offset) {
                                        /* we found one, proceed */
                                        spin_unlock(&last_ptr->refill_lock);
+                                       trace_btrfs_reserve_extent_cluster(root,
+                                               block_group, search_start,
+                                               num_bytes);
                                        goto checks;
                                }
                        } else if (!cached && loop > LOOP_CACHING_NOWAIT
@@ -5492,6 +5625,8 @@ checks:
                ins->objectid = search_start;
                ins->offset = num_bytes;
 
+               trace_btrfs_reserve_extent(orig_root, block_group,
+                                          search_start, num_bytes);
                if (offset < search_start)
                        btrfs_add_free_space(used_block_group, offset,
                                             search_start - offset);
@@ -5877,9 +6012,10 @@ int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 
        BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
 
-       ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
-                                        0, root_objectid, owner, offset,
-                                        BTRFS_ADD_DELAYED_EXTENT, NULL);
+       ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
+                                        ins->offset, 0,
+                                        root_objectid, owner, offset,
+                                        BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
        return ret;
 }
 
@@ -6032,10 +6168,11 @@ use_block_rsv(struct btrfs_trans_handle *trans,
        return ERR_PTR(-ENOSPC);
 }
 
-static void unuse_block_rsv(struct btrfs_block_rsv *block_rsv, u32 blocksize)
+static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
+                           struct btrfs_block_rsv *block_rsv, u32 blocksize)
 {
        block_rsv_add_bytes(block_rsv, blocksize, 0);
-       block_rsv_release_bytes(block_rsv, NULL, 0);
+       block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
 }
 
 /*
@@ -6049,7 +6186,7 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                                        struct btrfs_root *root, u32 blocksize,
                                        u64 parent, u64 root_objectid,
                                        struct btrfs_disk_key *key, int level,
-                                       u64 hint, u64 empty_size)
+                                       u64 hint, u64 empty_size, int for_cow)
 {
        struct btrfs_key ins;
        struct btrfs_block_rsv *block_rsv;
@@ -6065,7 +6202,7 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
        ret = btrfs_reserve_extent(trans, root, blocksize, blocksize,
                                   empty_size, hint, (u64)-1, &ins, 0);
        if (ret) {
-               unuse_block_rsv(block_rsv, blocksize);
+               unuse_block_rsv(root->fs_info, block_rsv, blocksize);
                return ERR_PTR(ret);
        }
 
@@ -6093,10 +6230,11 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                extent_op->update_flags = 1;
                extent_op->is_data = 0;
 
-               ret = btrfs_add_delayed_tree_ref(trans, ins.objectid,
+               ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
+                                       ins.objectid,
                                        ins.offset, parent, root_objectid,
                                        level, BTRFS_ADD_DELAYED_EXTENT,
-                                       extent_op);
+                                       extent_op, for_cow);
                BUG_ON(ret);
        }
        return buf;
@@ -6113,6 +6251,7 @@ struct walk_control {
        int keep_locks;
        int reada_slot;
        int reada_count;
+       int for_reloc;
 };
 
 #define DROP_REFERENCE 1
@@ -6251,9 +6390,9 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
        /* wc->stage == UPDATE_BACKREF */
        if (!(wc->flags[level] & flag)) {
                BUG_ON(!path->locks[level]);
-               ret = btrfs_inc_ref(trans, root, eb, 1);
+               ret = btrfs_inc_ref(trans, root, eb, 1, wc->for_reloc);
                BUG_ON(ret);
-               ret = btrfs_dec_ref(trans, root, eb, 0);
+               ret = btrfs_dec_ref(trans, root, eb, 0, wc->for_reloc);
                BUG_ON(ret);
                ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
                                                  eb->len, flag, 0);
@@ -6397,7 +6536,7 @@ skip:
                }
 
                ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
-                                       root->root_key.objectid, level - 1, 0);
+                               root->root_key.objectid, level - 1, 0, 0);
                BUG_ON(ret);
        }
        btrfs_tree_unlock(next);
@@ -6471,9 +6610,11 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
        if (wc->refs[level] == 1) {
                if (level == 0) {
                        if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
-                               ret = btrfs_dec_ref(trans, root, eb, 1);
+                               ret = btrfs_dec_ref(trans, root, eb, 1,
+                                                   wc->for_reloc);
                        else
-                               ret = btrfs_dec_ref(trans, root, eb, 0);
+                               ret = btrfs_dec_ref(trans, root, eb, 0,
+                                                   wc->for_reloc);
                        BUG_ON(ret);
                }
                /* make block locked assertion in clean_tree_block happy */
@@ -6500,7 +6641,7 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
                               btrfs_header_owner(path->nodes[level + 1]));
        }
 
-       btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
+       btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1, 0);
 out:
        wc->refs[level] = 0;
        wc->flags[level] = 0;
@@ -6584,7 +6725,8 @@ static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
  * blocks are properly updated.
  */
 void btrfs_drop_snapshot(struct btrfs_root *root,
-                        struct btrfs_block_rsv *block_rsv, int update_ref)
+                        struct btrfs_block_rsv *block_rsv, int update_ref,
+                        int for_reloc)
 {
        struct btrfs_path *path;
        struct btrfs_trans_handle *trans;
@@ -6672,6 +6814,7 @@ void btrfs_drop_snapshot(struct btrfs_root *root,
        wc->stage = DROP_REFERENCE;
        wc->update_ref = update_ref;
        wc->keep_locks = 0;
+       wc->for_reloc = for_reloc;
        wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
 
        while (1) {
@@ -6756,6 +6899,7 @@ out:
  * drop subtree rooted at tree block 'node'.
  *
  * NOTE: this function will unlock and release tree block 'node'
+ * only used by relocation code
  */
 int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root,
@@ -6800,6 +6944,7 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
        wc->stage = DROP_REFERENCE;
        wc->update_ref = 0;
        wc->keep_locks = 1;
+       wc->for_reloc = 1;
        wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
 
        while (1) {
@@ -7143,7 +7288,7 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
                 * space to fit our block group in.
                 */
                if (device->total_bytes > device->bytes_used + min_free) {
-                       ret = find_free_dev_extent(NULL, device, min_free,
+                       ret = find_free_dev_extent(device, min_free,
                                                   &dev_offset, NULL);
                        if (!ret)
                                dev_nr++;
@@ -7505,6 +7650,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
        ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
                                &cache->space_info);
        BUG_ON(ret);
+       update_global_block_rsv(root->fs_info);
 
        spin_lock(&cache->space_info->lock);
        cache->space_info->bytes_readonly += cache->bytes_super;