+static unsigned drop_outstanding_extent(struct inode *inode)
+{
+ unsigned dropped_extents = 0;
+
+ spin_lock(&BTRFS_I(inode)->lock);
+ BUG_ON(!BTRFS_I(inode)->outstanding_extents);
+ BTRFS_I(inode)->outstanding_extents--;
+
+ /*
+ * If we have more or the same amount of outsanding extents than we have
+ * reserved then we need to leave the reserved extents count alone.
+ */
+ if (BTRFS_I(inode)->outstanding_extents >=
+ BTRFS_I(inode)->reserved_extents)
+ goto out;
+
+ dropped_extents = BTRFS_I(inode)->reserved_extents -
+ BTRFS_I(inode)->outstanding_extents;
+ BTRFS_I(inode)->reserved_extents -= dropped_extents;
+out:
+ spin_unlock(&BTRFS_I(inode)->lock);
+ return dropped_extents;
+}
+