Btrfs: Update metadata reservation for delayed allocation

Introduce metadata reservation context for delayed allocation
and update various related functions.

This patch also introduces EXTENT_FIRST_DELALLOC control bit for
set/clear_extent_bit. It tells set/clear_bit_hook whether they
are processing the first extent_state with EXTENT_DELALLOC bit
set. This change is important if set/clear_extent_bit involves
multiple extent_state.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

9 files changed, 232 insertions, 415 deletions

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 7a4dee199832..40510d9351f5 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -137,8 +137,8 @@ struct btrfs_inode {
          * of extent items we've reserved metadata for.
          */
         spinlock_t accounting_lock;
+        atomic_t outstanding_extents;
         int reserved_extents;
-        int outstanding_extents;
 
         /*
          * ordered_data_close is set by truncate when a file that used
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e0aa9fb563e2..d4744192eada 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2079,19 +2079,8 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags);
 void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *ionde);
 void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
-
-int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root,
-                                          struct inode *inode, int num_items);
-int btrfs_reserve_metadata_for_delalloc(struct btrfs_root *root,
-                                        struct inode *inode, int num_items);
-int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
-                                u64 bytes);
-void btrfs_free_reserved_data_space(struct btrfs_root *root,
-                                    struct inode *inode, u64 bytes);
-void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
-                                 u64 bytes);
-void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
-                              u64 bytes);
+int btrfs_check_data_free_space(struct inode *inode, u64 bytes);
+void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes);
 int btrfs_trans_reserve_metadata(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root,
                                 int num_items, int *retries);
@@ -2099,6 +2088,10 @@ void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root);
 int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
                                 struct btrfs_pending_snapshot *pending);
+int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes);
+void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes);
+int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes);
+void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes);
 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv);
 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root);
 void btrfs_free_block_rsv(struct btrfs_root *root,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 657df6e002d3..b1822e752b4a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -64,12 +64,6 @@ static int find_next_key(struct btrfs_path *path, int level,
                          struct btrfs_key *key);
 static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
                             int dump_block_groups);
-static int maybe_allocate_chunk(struct btrfs_trans_handle *trans,
-                                struct btrfs_root *root,
-                                struct btrfs_space_info *sinfo, u64 num_bytes);
-static int shrink_delalloc(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root,
-                           struct btrfs_space_info *sinfo, u64 to_reclaim);
 
 static noinline int
 block_group_cache_done(struct btrfs_block_group_cache *cache)
@@ -2880,189 +2874,14 @@ void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
                                                        BTRFS_BLOCK_GROUP_DATA);
 }
 
-static u64 calculate_bytes_needed(struct btrfs_root *root, int num_items)
-{
-        u64 num_bytes;
-        int level;
-
-        level = BTRFS_MAX_LEVEL - 2;
-        /*
-         * NOTE: these calculations are absolutely the worst possible case.
-         * This assumes that _every_ item we insert will require a new leaf, and
-         * that the tree has grown to its maximum level size.
-         */
-
-        /*
-         * for every item we insert we could insert both an extent item and a
-         * extent ref item.  Then for ever item we insert, we will need to cow
-         * both the original leaf, plus the leaf to the left and right of it.
-         *
-         * Unless we are talking about the extent root, then we just want the
-         * number of items * 2, since we just need the extent item plus its ref.
-         */
-        if (root == root->fs_info->extent_root)
-                num_bytes = num_items * 2;
-        else
-                num_bytes = (num_items + (2 * num_items)) * 3;
-
-        /*
-         * num_bytes is total number of leaves we could need times the leaf
-         * size, and then for every leaf we could end up cow'ing 2 nodes per
-         * level, down to the leaf level.
-         */
-        num_bytes = (num_bytes * root->leafsize) +
-                (num_bytes * (level * 2)) * root->nodesize;
-
-        return num_bytes;
-}
-
-/*
- * Unreserve metadata space for delalloc.  If we have less reserved credits than
- * we have extents, this function does nothing.
- */
-int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root,
-                                          struct inode *inode, int num_items)
-{
-        struct btrfs_fs_info *info = root->fs_info;
-        struct btrfs_space_info *meta_sinfo;
-        u64 num_bytes;
-        u64 alloc_target;
-        bool bug = false;
-
-        /* get the space info for where the metadata will live */
-        alloc_target = btrfs_get_alloc_profile(root, 0);
-        meta_sinfo = __find_space_info(info, alloc_target);
-
-        num_bytes = calculate_bytes_needed(root->fs_info->extent_root,
-                                           num_items);
-
-        spin_lock(&meta_sinfo->lock);
-        spin_lock(&BTRFS_I(inode)->accounting_lock);
-        if (BTRFS_I(inode)->reserved_extents <=
-            BTRFS_I(inode)->outstanding_extents) {
-                spin_unlock(&BTRFS_I(inode)->accounting_lock);
-                spin_unlock(&meta_sinfo->lock);
-                return 0;
-        }
-        spin_unlock(&BTRFS_I(inode)->accounting_lock);
-
-        BTRFS_I(inode)->reserved_extents -= num_items;
-        BUG_ON(BTRFS_I(inode)->reserved_extents < 0);
-
-        if (meta_sinfo->bytes_delalloc < num_bytes) {
-                bug = true;
-                meta_sinfo->bytes_delalloc = 0;
-        } else {
-                meta_sinfo->bytes_delalloc -= num_bytes;
-        }
-        spin_unlock(&meta_sinfo->lock);
-
-        BUG_ON(bug);
-
-        return 0;
-}
-
-static void check_force_delalloc(struct btrfs_space_info *meta_sinfo)
-{
-        u64 thresh;
-
-        thresh = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
-                meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
-                meta_sinfo->bytes_super + meta_sinfo->bytes_root +
-                meta_sinfo->bytes_may_use;
-
-        thresh = meta_sinfo->total_bytes - thresh;
-        thresh *= 80;
-        do_div(thresh, 100);
-        if (thresh <= meta_sinfo->bytes_delalloc)
-                meta_sinfo->force_delalloc = 1;
-        else
-                meta_sinfo->force_delalloc = 0;
-}
-
-/*
- * Reserve metadata space for delalloc.
- */
-int btrfs_reserve_metadata_for_delalloc(struct btrfs_root *root,
-                                        struct inode *inode, int num_items)
-{
-        struct btrfs_fs_info *info = root->fs_info;
-        struct btrfs_space_info *meta_sinfo;
-        u64 num_bytes;
-        u64 used;
-        u64 alloc_target;
-        int flushed = 0;
-        int force_delalloc;
-
-        /* get the space info for where the metadata will live */
-        alloc_target = btrfs_get_alloc_profile(root, 0);
-        meta_sinfo = __find_space_info(info, alloc_target);
-
-        num_bytes = calculate_bytes_needed(root->fs_info->extent_root,
-                                           num_items);
-again:
-        spin_lock(&meta_sinfo->lock);
-
-        force_delalloc = meta_sinfo->force_delalloc;
-
-        if (unlikely(!meta_sinfo->bytes_root))
-                meta_sinfo->bytes_root = calculate_bytes_needed(root, 6);
-
-        if (!flushed)
-                meta_sinfo->bytes_delalloc += num_bytes;
-
-        used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
-                meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly +
-                meta_sinfo->bytes_super + meta_sinfo->bytes_root +
-                meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc;
-
-        if (used > meta_sinfo->total_bytes) {
-                flushed++;
-
-                if (flushed == 1) {
-                        if (maybe_allocate_chunk(NULL, root, meta_sinfo,
-                                                 num_bytes))
-                                goto again;
-                        flushed++;
-                } else {
-                        spin_unlock(&meta_sinfo->lock);
-                }
-
-                if (flushed == 2) {
-                        filemap_flush(inode->i_mapping);
-                        goto again;
-                } else if (flushed == 3) {
-                        shrink_delalloc(NULL, root, meta_sinfo, num_bytes);
-                        goto again;
-                }
-                spin_lock(&meta_sinfo->lock);
-                meta_sinfo->bytes_delalloc -= num_bytes;
-                spin_unlock(&meta_sinfo->lock);
-                printk(KERN_ERR "enospc, has %d, reserved %d\n",
-                       BTRFS_I(inode)->outstanding_extents,
-                       BTRFS_I(inode)->reserved_extents);
-                dump_space_info(meta_sinfo, 0, 0);
-                return -ENOSPC;
-        }
-
-        BTRFS_I(inode)->reserved_extents += num_items;
-        check_force_delalloc(meta_sinfo);
-        spin_unlock(&meta_sinfo->lock);
-
-        if (!flushed && force_delalloc)
-                filemap_flush(inode->i_mapping);
-
-        return 0;
-}
-
 /*
  * This will check the space that the inode allocates from to make sure we have
  * enough space for bytes.
  */
-int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
-                                u64 bytes)
+int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
 {
         struct btrfs_space_info *data_sinfo;
+        struct btrfs_root *root = BTRFS_I(inode)->root;
         u64 used;
         int ret = 0, committed = 0;
 
@@ -3147,12 +2966,13 @@ alloc:
 }
 
 /*
- * if there was an error for whatever reason after calling
- * btrfs_check_data_free_space, call this so we can cleanup the counters.
+ * called when we are clearing an delalloc extent from the
+ * inode's io_tree or there was an error for whatever reason
+ * after calling btrfs_check_data_free_space
  */
-void btrfs_free_reserved_data_space(struct btrfs_root *root,
-                                    struct inode *inode, u64 bytes)
+void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
 {
+        struct btrfs_root *root = BTRFS_I(inode)->root;
         struct btrfs_space_info *data_sinfo;
 
         /* make sure bytes are sectorsize aligned */
@@ -3165,48 +2985,6 @@ void btrfs_free_reserved_data_space(struct btrfs_root *root,
         spin_unlock(&data_sinfo->lock);
 }
 
-/* called when we are adding a delalloc extent to the inode's io_tree */
-void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
-                                  u64 bytes)
-{
-        struct btrfs_space_info *data_sinfo;
-
-        /* get the space info for where this inode will be storing its data */
-        data_sinfo = BTRFS_I(inode)->space_info;
-
-        /* make sure we have enough space to handle the data first */
-        spin_lock(&data_sinfo->lock);
-        data_sinfo->bytes_delalloc += bytes;
-
-        /*
-         * we are adding a delalloc extent without calling
-         * btrfs_check_data_free_space first.  This happens on a weird
-         * writepage condition, but shouldn't hurt our accounting
-         */
-        if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
-                data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
-                BTRFS_I(inode)->reserved_bytes = 0;
-        } else {
-                data_sinfo->bytes_may_use -= bytes;
-                BTRFS_I(inode)->reserved_bytes -= bytes;
-        }
-
-        spin_unlock(&data_sinfo->lock);
-}
-
-/* called when we are clearing an delalloc extent from the inode's io_tree */
-void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
-                              u64 bytes)
-{
-        struct btrfs_space_info *info;
-
-        info = BTRFS_I(inode)->space_info;
-
-        spin_lock(&info->lock);
-        info->bytes_delalloc -= bytes;
-        spin_unlock(&info->lock);
-}
-
 static void force_metadata_allocation(struct btrfs_fs_info *info)
 {
         struct list_head *head = &info->space_info;
@@ -3331,18 +3109,19 @@ static int maybe_allocate_chunk(struct btrfs_trans_handle *trans,
  * shrink metadata reservation for delalloc
  */
 static int shrink_delalloc(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root,
-                           struct btrfs_space_info *sinfo, u64 to_reclaim)
+                           struct btrfs_root *root, u64 to_reclaim)
 {
+        struct btrfs_block_rsv *block_rsv;
         u64 reserved;
         u64 max_reclaim;
         u64 reclaimed = 0;
         int pause = 1;
         int ret;
 
-        spin_lock(&sinfo->lock);
-        reserved = sinfo->bytes_delalloc;
-        spin_unlock(&sinfo->lock);
+        block_rsv = &root->fs_info->delalloc_block_rsv;
+        spin_lock(&block_rsv->lock);
+        reserved = block_rsv->reserved;
+        spin_unlock(&block_rsv->lock);
 
         if (reserved == 0)
                 return 0;
@@ -3361,11 +3140,11 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
                         pause = 1;
                 }
 
-                spin_lock(&sinfo->lock);
-                if (reserved > sinfo->bytes_delalloc)
-                        reclaimed = reserved - sinfo->bytes_delalloc;
-                reserved = sinfo->bytes_delalloc;
-                spin_unlock(&sinfo->lock);
+                spin_lock(&block_rsv->lock);
+                if (reserved > block_rsv->reserved)
+                        reclaimed = reserved - block_rsv->reserved;
+                reserved = block_rsv->reserved;
+                spin_unlock(&block_rsv->lock);
 
                 if (reserved == 0 || reclaimed >= max_reclaim)
                         break;
@@ -3394,7 +3173,7 @@ static int should_retry_reserve(struct btrfs_trans_handle *trans,
         if (trans && trans->transaction->in_commit)
                 return -ENOSPC;
 
-        ret = shrink_delalloc(trans, root, space_info, num_bytes);
+        ret = shrink_delalloc(trans, root, num_bytes);
         if (ret)
                 return ret;
 
@@ -3754,6 +3533,108 @@ int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
         return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }
 
+static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes)
+{
+        return num_bytes >>= 3;
+}
+
+int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
+{
+        struct btrfs_root *root = BTRFS_I(inode)->root;
+        struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
+        u64 to_reserve;
+        int nr_extents;
+        int retries = 0;
+        int ret;
+
+        if (btrfs_transaction_in_commit(root->fs_info))
+                schedule_timeout(1);
+
+        num_bytes = ALIGN(num_bytes, root->sectorsize);
+again:
+        spin_lock(&BTRFS_I(inode)->accounting_lock);
+        nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents) + 1;
+        if (nr_extents > BTRFS_I(inode)->reserved_extents) {
+                nr_extents -= BTRFS_I(inode)->reserved_extents;
+                to_reserve = calc_trans_metadata_size(root, nr_extents);
+        } else {
+                nr_extents = 0;
+                to_reserve = 0;
+        }
+
+        to_reserve += calc_csum_metadata_size(inode, num_bytes);
+        ret = reserve_metadata_bytes(block_rsv, to_reserve);
+        if (ret) {
+                spin_unlock(&BTRFS_I(inode)->accounting_lock);
+                ret = should_retry_reserve(NULL, root, block_rsv, to_reserve,
+                                           &retries);
+                if (ret > 0)
+                        goto again;
+                return ret;
+        }
+
+        BTRFS_I(inode)->reserved_extents += nr_extents;
+        atomic_inc(&BTRFS_I(inode)->outstanding_extents);
+        spin_unlock(&BTRFS_I(inode)->accounting_lock);
+
+        block_rsv_add_bytes(block_rsv, to_reserve, 1);
+
+        if (block_rsv->size > 512 * 1024 * 1024)
+                shrink_delalloc(NULL, root, to_reserve);
+
+        return 0;
+}
+
+void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
+{
+        struct btrfs_root *root = BTRFS_I(inode)->root;
+        u64 to_free;
+        int nr_extents;
+
+        num_bytes = ALIGN(num_bytes, root->sectorsize);
+        atomic_dec(&BTRFS_I(inode)->outstanding_extents);
+
+        spin_lock(&BTRFS_I(inode)->accounting_lock);
+        nr_extents = atomic_read(&BTRFS_I(inode)->outstanding_extents);
+        if (nr_extents < BTRFS_I(inode)->reserved_extents) {
+                nr_extents = BTRFS_I(inode)->reserved_extents - nr_extents;
+                BTRFS_I(inode)->reserved_extents -= nr_extents;
+        } else {
+                nr_extents = 0;
+        }
+        spin_unlock(&BTRFS_I(inode)->accounting_lock);
+
+        to_free = calc_csum_metadata_size(inode, num_bytes);
+        if (nr_extents > 0)
+                to_free += calc_trans_metadata_size(root, nr_extents);
+
+        btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
+                                to_free);
+}
+
+int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
+{
+        int ret;
+
+        ret = btrfs_check_data_free_space(inode, num_bytes);
+        if (ret)
+                return ret;
+
+        ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
+        if (ret) {
+                btrfs_free_reserved_data_space(inode, num_bytes);
+                return ret;
+        }
+
+        return 0;
+}
+
+void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
+{
+        btrfs_delalloc_release_metadata(inode, num_bytes);
+        btrfs_free_reserved_data_space(inode, num_bytes);
+}
+
 static int update_block_group(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
                               u64 bytenr, u64 num_bytes, int alloc)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d2d03684fab2..1a57c17d4029 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -335,21 +335,18 @@ static int merge_state(struct extent_io_tree *tree,
 }
 
 static int set_state_cb(struct extent_io_tree *tree,
-                         struct extent_state *state,
-                         unsigned long bits)
+                         struct extent_state *state, int *bits)
 {
         if (tree->ops && tree->ops->set_bit_hook) {
                 return tree->ops->set_bit_hook(tree->mapping->host,
-                                               state->start, state->end,
-                                               state->state, bits);
+                                               state, bits);
         }
 
         return 0;
 }
 
 static void clear_state_cb(struct extent_io_tree *tree,
-                           struct extent_state *state,
-                           unsigned long bits)
+                           struct extent_state *state, int *bits)
 {
         if (tree->ops && tree->ops->clear_bit_hook)
                 tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
@@ -367,9 +364,10 @@ static void clear_state_cb(struct extent_io_tree *tree,
  */
 static int insert_state(struct extent_io_tree *tree,
                         struct extent_state *state, u64 start, u64 end,
-                        int bits)
+                        int *bits)
 {
         struct rb_node *node;
+        int bits_to_set = *bits & ~EXTENT_CTLBITS;
         int ret;
 
         if (end < start) {
@@ -384,9 +382,9 @@ static int insert_state(struct extent_io_tree *tree,
         if (ret)
                 return ret;
 
-        if (bits & EXTENT_DIRTY)
+        if (bits_to_set & EXTENT_DIRTY)
                 tree->dirty_bytes += end - start + 1;
-        state->state |= bits;
+        state->state |= bits_to_set;
         node = tree_insert(&tree->state, end, &state->rb_node);
         if (node) {
                 struct extent_state *found;
@@ -456,13 +454,13 @@ static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
  * struct is freed and removed from the tree
  */
 static int clear_state_bit(struct extent_io_tree *tree,
-                            struct extent_state *state, int bits, int wake,
-                            int delete)
+                            struct extent_state *state,
+                            int *bits, int wake)
 {
-        int bits_to_clear = bits & ~EXTENT_DO_ACCOUNTING;
+        int bits_to_clear = *bits & ~EXTENT_CTLBITS;
         int ret = state->state & bits_to_clear;
 
-        if ((bits & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
+        if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
                 u64 range = state->end - state->start + 1;
                 WARN_ON(range > tree->dirty_bytes);
                 tree->dirty_bytes -= range;
@@ -471,9 +469,8 @@ static int clear_state_bit(struct extent_io_tree *tree,
         state->state &= ~bits_to_clear;
         if (wake)
                 wake_up(&state->wq);
-        if (delete || state->state == 0) {
+        if (state->state == 0) {
                 if (state->tree) {
-                        clear_state_cb(tree, state, state->state);
                         rb_erase(&state->rb_node, &tree->state);
                         state->tree = NULL;
                         free_extent_state(state);
@@ -514,6 +511,10 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
         int set = 0;
         int clear = 0;
 
+        if (delete)
+                bits |= ~EXTENT_CTLBITS;
+        bits |= EXTENT_FIRST_DELALLOC;
+
         if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
                 clear = 1;
 again:
@@ -580,8 +581,7 @@ hit_next:
                 if (err)
                         goto out;
                 if (state->end <= end) {
-                        set |= clear_state_bit(tree, state, bits, wake,
-                                               delete);
+                        set |= clear_state_bit(tree, state, &bits, wake);
                         if (last_end == (u64)-1)
                                 goto out;
                         start = last_end + 1;
@@ -602,7 +602,7 @@ hit_next:
                 if (wake)
                         wake_up(&state->wq);
 
-                set |= clear_state_bit(tree, prealloc, bits, wake, delete);
+                set |= clear_state_bit(tree, prealloc, &bits, wake);
 
                 prealloc = NULL;
                 goto out;
@@ -613,7 +613,7 @@ hit_next:
         else
                 next_node = NULL;
 
-        set |= clear_state_bit(tree, state, bits, wake, delete);
+        set |= clear_state_bit(tree, state, &bits, wake);
         if (last_end == (u64)-1)
                 goto out;
         start = last_end + 1;
@@ -706,19 +706,19 @@ out:
 
 static int set_state_bits(struct extent_io_tree *tree,
                            struct extent_state *state,
-                           int bits)
+                           int *bits)
 {
         int ret;
+        int bits_to_set = *bits & ~EXTENT_CTLBITS;
 
         ret = set_state_cb(tree, state, bits);
         if (ret)
                 return ret;
-
-        if ((bits & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
+        if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
                 u64 range = state->end - state->start + 1;
                 tree->dirty_bytes += range;
         }
-        state->state |= bits;
+        state->state |= bits_to_set;
 
         return 0;
 }
@@ -757,6 +757,7 @@ static int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
         u64 last_start;
         u64 last_end;
 
+        bits |= EXTENT_FIRST_DELALLOC;
 again:
         if (!prealloc && (mask & __GFP_WAIT)) {
                 prealloc = alloc_extent_state(mask);
@@ -778,7 +779,7 @@ again:
          */
         node = tree_search(tree, start);
         if (!node) {
-                err = insert_state(tree, prealloc, start, end, bits);
+                err = insert_state(tree, prealloc, start, end, &bits);
                 prealloc = NULL;
                 BUG_ON(err == -EEXIST);
                 goto out;
@@ -802,7 +803,7 @@ hit_next:
                         goto out;
                 }
 
-                err = set_state_bits(tree, state, bits);
+                err = set_state_bits(tree, state, &bits);
                 if (err)
                         goto out;
 
@@ -852,7 +853,7 @@ hit_next:
                 if (err)
                         goto out;
                 if (state->end <= end) {
-                        err = set_state_bits(tree, state, bits);
+                        err = set_state_bits(tree, state, &bits);
                         if (err)
                                 goto out;
                         cache_state(state, cached_state);
@@ -877,7 +878,7 @@ hit_next:
                 else
                         this_end = last_start - 1;
                 err = insert_state(tree, prealloc, start, this_end,
-                                   bits);
+                                   &bits);
                 BUG_ON(err == -EEXIST);
                 if (err) {
                         prealloc = NULL;
@@ -903,7 +904,7 @@ hit_next:
                 err = split_state(tree, state, prealloc, end + 1);
                 BUG_ON(err == -EEXIST);
 
-                err = set_state_bits(tree, prealloc, bits);
+                err = set_state_bits(tree, prealloc, &bits);
                 if (err) {
                         prealloc = NULL;
                         goto out;
@@ -966,8 +967,7 @@ int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
 {
         return clear_extent_bit(tree, start, end,
                                 EXTENT_DIRTY | EXTENT_DELALLOC |
-                                EXTENT_DO_ACCOUNTING, 0, 0,
-                                NULL, mask);
+                                EXTENT_DO_ACCOUNTING, 0, 0, NULL, mask);
 }
 
 int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
@@ -1435,9 +1435,6 @@ int extent_clear_unlock_delalloc(struct inode *inode,
         if (op & EXTENT_CLEAR_DELALLOC)
                 clear_bits |= EXTENT_DELALLOC;
 
-        if (op & EXTENT_CLEAR_ACCOUNTING)
-                clear_bits |= EXTENT_DO_ACCOUNTING;
-
         clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS);
         if (!(op & (EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
                     EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK |
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index bbab4813646f..86f10dc791d9 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -16,7 +16,9 @@
 #define EXTENT_BOUNDARY (1 << 9)
 #define EXTENT_NODATASUM (1 << 10)
 #define EXTENT_DO_ACCOUNTING (1 << 11)
+#define EXTENT_FIRST_DELALLOC (1 << 12)
 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
+#define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
 
 /* flags for bio submission */
 #define EXTENT_BIO_COMPRESSED 1
@@ -69,10 +71,10 @@ struct extent_io_ops {
                                     struct extent_state *state);
         int (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
                                       struct extent_state *state, int uptodate);
-        int (*set_bit_hook)(struct inode *inode, u64 start, u64 end,
-                            unsigned long old, unsigned long bits);
+        int (*set_bit_hook)(struct inode *inode, struct extent_state *state,
+                            int *bits);
         int (*clear_bit_hook)(struct inode *inode, struct extent_state *state,
-                              unsigned long bits);
+                              int *bits);
         int (*merge_extent_hook)(struct inode *inode,
                                  struct extent_state *new,
                                  struct extent_state *other);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 41e09e24e295..6d8f817eadb5 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -852,13 +852,6 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
 
         vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
 
-        /* do the reserve before the mutex lock in case we have to do some
-         * flushing.  We wouldn't deadlock, but this is more polite.
-         */
-        err = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
-        if (err)
-                goto out_nolock;
-
         mutex_lock(&inode->i_mutex);
 
         current->backing_dev_info = inode->i_mapping->backing_dev_info;
@@ -921,7 +914,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                 WARN_ON(num_pages > nrptrs);
                 memset(pages, 0, sizeof(struct page *) * nrptrs);
 
-                ret = btrfs_check_data_free_space(root, inode, write_bytes);
+                ret = btrfs_delalloc_reserve_space(inode, write_bytes);
                 if (ret)
                         goto out;
 
@@ -929,26 +922,20 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                                     pos, first_index, last_index,
                                     write_bytes);
                 if (ret) {
-                        btrfs_free_reserved_data_space(root, inode,
-                                                       write_bytes);
+                        btrfs_delalloc_release_space(inode, write_bytes);
                         goto out;
                 }
 
                 ret = btrfs_copy_from_user(pos, num_pages,
                                            write_bytes, pages, buf);
-                if (ret) {
-                        btrfs_free_reserved_data_space(root, inode,
-                                                       write_bytes);
-                        btrfs_drop_pages(pages, num_pages);
-                        goto out;
+                if (ret == 0) {
+                        dirty_and_release_pages(NULL, root, file, pages,
+                                                num_pages, pos, write_bytes);
                 }
 
-                ret = dirty_and_release_pages(NULL, root, file, pages,
-                                              num_pages, pos, write_bytes);
                 btrfs_drop_pages(pages, num_pages);
                 if (ret) {
-                        btrfs_free_reserved_data_space(root, inode,
-                                                       write_bytes);
+                        btrfs_delalloc_release_space(inode, write_bytes);
                         goto out;
                 }
 
@@ -975,9 +962,7 @@ out:
         mutex_unlock(&inode->i_mutex);
         if (ret)
                 err = ret;
-        btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
 
-out_nolock:
         kfree(pages);
         if (pinned[0])
                 page_cache_release(pinned[0]);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c4b0fd12df68..6e54665d37f7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -252,6 +252,7 @@ static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
                                    inline_len, compressed_size,
                                    compressed_pages);
         BUG_ON(ret);
+        btrfs_delalloc_release_metadata(inode, end + 1 - start);
         btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
         return 0;
 }
@@ -414,6 +415,7 @@ again:
                 trans = btrfs_join_transaction(root, 1);
                 BUG_ON(!trans);
                 btrfs_set_trans_block_group(trans, inode);
+                trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 
                 /* lets try to make an inline extent */
                 if (ret || total_in < (actual_end - start)) {
@@ -439,7 +441,6 @@ again:
                              start, end, NULL,
                              EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
                              EXTENT_CLEAR_DELALLOC |
-                             EXTENT_CLEAR_ACCOUNTING |
                              EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
 
                         btrfs_end_transaction(trans, root);
@@ -734,6 +735,7 @@ static noinline int cow_file_range(struct inode *inode,
         trans = btrfs_join_transaction(root, 1);
         BUG_ON(!trans);
         btrfs_set_trans_block_group(trans, inode);
+        trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 
         actual_end = min_t(u64, isize, end + 1);
 
@@ -753,7 +755,6 @@ static noinline int cow_file_range(struct inode *inode,
                                      EXTENT_CLEAR_UNLOCK_PAGE |
                                      EXTENT_CLEAR_UNLOCK |
                                      EXTENT_CLEAR_DELALLOC |
-                                     EXTENT_CLEAR_ACCOUNTING |
                                      EXTENT_CLEAR_DIRTY |
                                      EXTENT_SET_WRITEBACK |
                                      EXTENT_END_WRITEBACK);
@@ -1226,15 +1227,13 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page,
 }
 
 static int btrfs_split_extent_hook(struct inode *inode,
-                                    struct extent_state *orig, u64 split)
+                                   struct extent_state *orig, u64 split)
 {
+        /* not delalloc, ignore it */
         if (!(orig->state & EXTENT_DELALLOC))
                 return 0;
 
-        spin_lock(&BTRFS_I(inode)->accounting_lock);
-        BTRFS_I(inode)->outstanding_extents++;
-        spin_unlock(&BTRFS_I(inode)->accounting_lock);
-
+        atomic_inc(&BTRFS_I(inode)->outstanding_extents);
         return 0;
 }
 
@@ -1252,10 +1251,7 @@ static int btrfs_merge_extent_hook(struct inode *inode,
         if (!(other->state & EXTENT_DELALLOC))
                 return 0;
 
-        spin_lock(&BTRFS_I(inode)->accounting_lock);
-        BTRFS_I(inode)->outstanding_extents--;
-        spin_unlock(&BTRFS_I(inode)->accounting_lock);
-
+        atomic_dec(&BTRFS_I(inode)->outstanding_extents);
         return 0;
 }
 
@@ -1264,8 +1260,8 @@ static int btrfs_merge_extent_hook(struct inode *inode,
  * bytes in this file, and to maintain the list of inodes that
  * have pending delalloc work to be done.
  */
-static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
-                       unsigned long old, unsigned long bits)
+static int btrfs_set_bit_hook(struct inode *inode,
+                              struct extent_state *state, int *bits)
 {
 
         /*
@@ -1273,17 +1269,18 @@ static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
          * but in this case, we are only testeing for the DELALLOC
          * bit, which is only set or cleared with irqs on
          */
-        if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
+        if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
                 struct btrfs_root *root = BTRFS_I(inode)->root;
+                u64 len = state->end + 1 - state->start;
 
-                spin_lock(&BTRFS_I(inode)->accounting_lock);
-                BTRFS_I(inode)->outstanding_extents++;
-                spin_unlock(&BTRFS_I(inode)->accounting_lock);
-                btrfs_delalloc_reserve_space(root, inode, end - start + 1);
+                if (*bits & EXTENT_FIRST_DELALLOC)
+                        *bits &= ~EXTENT_FIRST_DELALLOC;
+                else
+                        atomic_inc(&BTRFS_I(inode)->outstanding_extents);
 
                 spin_lock(&root->fs_info->delalloc_lock);
-                BTRFS_I(inode)->delalloc_bytes += end - start + 1;
-                root->fs_info->delalloc_bytes += end - start + 1;
+                BTRFS_I(inode)->delalloc_bytes += len;
+                root->fs_info->delalloc_bytes += len;
                 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
                         list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
                                       &root->fs_info->delalloc_inodes);
@@ -1297,45 +1294,32 @@ static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
  * extent_io.c clear_bit_hook, see set_bit_hook for why
  */
 static int btrfs_clear_bit_hook(struct inode *inode,
-                                struct extent_state *state, unsigned long bits)
+                                struct extent_state *state, int *bits)
 {
         /*
          * set_bit and clear bit hooks normally require _irqsave/restore
          * but in this case, we are only testeing for the DELALLOC
          * bit, which is only set or cleared with irqs on
          */
-        if ((state->state & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
+        if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
                 struct btrfs_root *root = BTRFS_I(inode)->root;
+                u64 len = state->end + 1 - state->start;
 
-                if (bits & EXTENT_DO_ACCOUNTING) {
-                        spin_lock(&BTRFS_I(inode)->accounting_lock);
-                        WARN_ON(!BTRFS_I(inode)->outstanding_extents);
-                        BTRFS_I(inode)->outstanding_extents--;
-                        spin_unlock(&BTRFS_I(inode)->accounting_lock);
-                        btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
-                }
+                if (*bits & EXTENT_FIRST_DELALLOC)
+                        *bits &= ~EXTENT_FIRST_DELALLOC;
+                else if (!(*bits & EXTENT_DO_ACCOUNTING))
+                        atomic_dec(&BTRFS_I(inode)->outstanding_extents);
+
+                if (*bits & EXTENT_DO_ACCOUNTING)
+                        btrfs_delalloc_release_metadata(inode, len);
+
+                if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID)
+                        btrfs_free_reserved_data_space(inode, len);
 
                 spin_lock(&root->fs_info->delalloc_lock);
-                if (state->end - state->start + 1 >
-                    root->fs_info->delalloc_bytes) {
-                        printk(KERN_INFO "btrfs warning: delalloc account "
-                               "%llu %llu\n",
-                               (unsigned long long)
-                               state->end - state->start + 1,
-                               (unsigned long long)
-                               root->fs_info->delalloc_bytes);
-                        btrfs_delalloc_free_space(root, inode, (u64)-1);
-                        root->fs_info->delalloc_bytes = 0;
-                        BTRFS_I(inode)->delalloc_bytes = 0;
-                } else {
-                        btrfs_delalloc_free_space(root, inode,
-                                                  state->end -
-                                                  state->start + 1);
-                        root->fs_info->delalloc_bytes -= state->end -
-                                state->start + 1;
-                        BTRFS_I(inode)->delalloc_bytes -= state->end -
-                                state->start + 1;
-                }
+                root->fs_info->delalloc_bytes -= len;
+                BTRFS_I(inode)->delalloc_bytes -= len;
+
                 if (BTRFS_I(inode)->delalloc_bytes == 0 &&
                     !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
                         list_del_init(&BTRFS_I(inode)->delalloc_inodes);
@@ -1520,6 +1504,7 @@ again:
                 goto again;
         }
 
+        BUG();
         btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
         ClearPageChecked(page);
 out:
@@ -1650,7 +1635,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 {
         struct btrfs_root *root = BTRFS_I(inode)->root;
-        struct btrfs_trans_handle *trans;
+        struct btrfs_trans_handle *trans = NULL;
         struct btrfs_ordered_extent *ordered_extent = NULL;
         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
         struct extent_state *cached_state = NULL;
@@ -1668,9 +1653,10 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
                 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
                 if (!ret) {
                         trans = btrfs_join_transaction(root, 1);
+                        btrfs_set_trans_block_group(trans, inode);
+                        trans->block_rsv = &root->fs_info->delalloc_block_rsv;
                         ret = btrfs_update_inode(trans, root, inode);
                         BUG_ON(ret);
-                        btrfs_end_transaction(trans, root);
                 }
                 goto out;
         }
@@ -1680,6 +1666,8 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
                          0, &cached_state, GFP_NOFS);
 
         trans = btrfs_join_transaction(root, 1);
+        btrfs_set_trans_block_group(trans, inode);
+        trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 
         if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
                 compressed = 1;
@@ -1711,12 +1699,13 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
         add_pending_csums(trans, inode, ordered_extent->file_offset,
                           &ordered_extent->list);
 
-        /* this also removes the ordered extent from the tree */
         btrfs_ordered_update_i_size(inode, 0, ordered_extent);
         ret = btrfs_update_inode(trans, root, inode);
         BUG_ON(ret);
-        btrfs_end_transaction(trans, root);
 out:
+        btrfs_delalloc_release_metadata(inode, ordered_extent->len);
+        if (trans)
+                btrfs_end_transaction(trans, root);
         /* once for us */
         btrfs_put_ordered_extent(ordered_extent);
         /* once for the tree */
@@ -3219,11 +3208,7 @@ static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
 
         if ((offset & (blocksize - 1)) == 0)
                 goto out;
-        ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
-        if (ret)
-                goto out;
-
-        ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
+        ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
         if (ret)
                 goto out;
 
@@ -3231,8 +3216,7 @@ static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
 again:
         page = grab_cache_page(mapping, index);
         if (!page) {
-                btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
-                btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
+                btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
                 goto out;
         }
 
@@ -3295,8 +3279,7 @@ again:
 
 out_unlock:
         if (ret)
-                btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
-        btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
+                btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
         unlock_page(page);
         page_cache_release(page);
 out:
@@ -4878,6 +4861,7 @@ again:
                         }
                         flush_dcache_page(page);
                 } else if (create && PageUptodate(page)) {
+                        WARN_ON(1);
                         if (!trans) {
                                 kunmap(page);
                                 free_extent_map(em);
@@ -5142,7 +5126,7 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         u64 page_start;
         u64 page_end;
 
-        ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
+        ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
         if (ret) {
                 if (ret == -ENOMEM)
                         ret = VM_FAULT_OOM;
@@ -5151,13 +5135,6 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
                 goto out;
         }
 
-        ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
-        if (ret) {
-                btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
-                ret = VM_FAULT_SIGBUS;
-                goto out;
-        }
-
         ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
 again:
         lock_page(page);
@@ -5167,7 +5144,6 @@ again:
 
         if ((page->mapping != inode->i_mapping) ||
             (page_start >= size)) {
-                btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
                 /* page got truncated out from underneath us */
                 goto out_unlock;
         }
@@ -5208,7 +5184,6 @@ again:
                 unlock_extent_cached(io_tree, page_start, page_end,
                                      &cached_state, GFP_NOFS);
                 ret = VM_FAULT_SIGBUS;
-                btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
                 goto out_unlock;
         }
         ret = 0;
@@ -5235,10 +5210,10 @@ again:
         unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
 
 out_unlock:
-        btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
         if (!ret)
                 return VM_FAULT_LOCKED;
         unlock_page(page);
+        btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
 out:
         return ret;
 }
@@ -5383,7 +5358,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
         ei->last_unlink_trans = 0;
 
         spin_lock_init(&ei->accounting_lock);
-        ei->outstanding_extents = 0;
+        atomic_set(&ei->outstanding_extents, 0);
         ei->reserved_extents = 0;
 
         ei->ordered_data_close = 0;
@@ -5411,6 +5386,8 @@ void btrfs_destroy_inode(struct inode *inode)
 
         WARN_ON(!list_empty(&inode->i_dentry));
         WARN_ON(inode->i_data.nrpages);
+        WARN_ON(atomic_read(&BTRFS_I(inode)->outstanding_extents));
+        WARN_ON(BTRFS_I(inode)->reserved_extents);
 
         /*
          * This can happen where we create an inode, but somebody else also
@@ -5970,8 +5947,7 @@ static long btrfs_fallocate(struct inode *inode, int mode,
                         goto out;
         }
 
-        ret = btrfs_check_data_free_space(BTRFS_I(inode)->root, inode,
-                                          alloc_end - alloc_start);
+        ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
         if (ret)
                 goto out;
 
@@ -6037,8 +6013,7 @@ static long btrfs_fallocate(struct inode *inode, int mode,
         unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
                              &cached_state, GFP_NOFS);
 
-        btrfs_free_reserved_data_space(BTRFS_I(inode)->root, inode,
-                                       alloc_end - alloc_start);
+        btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
 out:
         mutex_unlock(&inode->i_mutex);
         return ret;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3066da468c6d..6a706e691377 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -587,19 +587,9 @@ static int btrfs_defrag_file(struct file *file,
                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
                         BTRFS_I(inode)->force_compress = 1;
 
-                ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
-                if (ret) {
-                        ret = -ENOSPC;
-                        break;
-                }
-
-                ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
-                if (ret) {
-                        btrfs_free_reserved_data_space(root, inode,
-                                                       PAGE_CACHE_SIZE);
-                        ret = -ENOSPC;
-                        break;
-                }
+                ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
+                if (ret)
+                        goto err_unlock;
 again:
                 if (inode->i_size == 0 ||
                     i > ((inode->i_size - 1) >> PAGE_CACHE_SHIFT)) {
@@ -608,8 +598,10 @@ again:
                 }
 
                 page = grab_cache_page(inode->i_mapping, i);
-                if (!page)
+                if (!page) {
+                        ret = -ENOMEM;
                         goto err_reservations;
+                }
 
                 if (!PageUptodate(page)) {
                         btrfs_readpage(NULL, page);
@@ -617,6 +609,7 @@ again:
                         if (!PageUptodate(page)) {
                                 unlock_page(page);
                                 page_cache_release(page);
+                                ret = -EIO;
                                 goto err_reservations;
                         }
                 }
@@ -630,8 +623,7 @@ again:
                 wait_on_page_writeback(page);
 
                 if (PageDirty(page)) {
-                        btrfs_free_reserved_data_space(root, inode,
-                                                       PAGE_CACHE_SIZE);
+                        btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
                         goto loop_unlock;
                 }
 
@@ -669,7 +661,6 @@ loop_unlock:
                 page_cache_release(page);
                 mutex_unlock(&inode->i_mutex);
 
-                btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
                 i++;
         }
@@ -699,9 +690,9 @@ loop_unlock:
         return 0;
 
 err_reservations:
+        btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+err_unlock:
         mutex_unlock(&inode->i_mutex);
-        btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
-        btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
         return ret;
 }
 
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index a127c0ebb2dc..c9f1020572f2 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -311,13 +311,6 @@ static int __btrfs_remove_ordered_extent(struct inode *inode,
         tree->last = NULL;
         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 
-        spin_lock(&BTRFS_I(inode)->accounting_lock);
-        WARN_ON(!BTRFS_I(inode)->outstanding_extents);
-        BTRFS_I(inode)->outstanding_extents--;
-        spin_unlock(&BTRFS_I(inode)->accounting_lock);
-        btrfs_unreserve_metadata_for_delalloc(BTRFS_I(inode)->root,
-                                              inode, 1);
-
         spin_lock(&root->fs_info->ordered_extent_lock);
         list_del_init(&entry->root_extent_list);