Btrfs: update free_chunk_space during allocting a new chunk

We should update free_chunk_space in time when we allocate a new chunk,
not when we deal with the pending device update and block group insertion,
because we need the real free_chunk_space data to calculate the reserved
space, if we don't update it in time, we would consider the disk space which
has be allocated as free space, and would use it to do overcommit reservation.
Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 45e0b5d0f6dd1a985a3cfa0f90a777fea6f78434..d8e4a3d1ad89814e6b56fbb47d53751c80827d0a 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4432,6 +4432,11 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
        for (i = 0; i < map->num_stripes; i++)
                map->stripes[i].dev->bytes_used += stripe_size;
 
+       spin_lock(&extent_root->fs_info->free_chunk_lock);
+       extent_root->fs_info->free_chunk_space -= (stripe_size *
+                                                  map->num_stripes);
+       spin_unlock(&extent_root->fs_info->free_chunk_lock);
+
        free_extent_map(em);
        check_raid56_incompat_flag(extent_root->fs_info, type);
 
@@ -4515,11 +4520,6 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
                        goto out;
        }
 
-       spin_lock(&extent_root->fs_info->free_chunk_lock);
-       extent_root->fs_info->free_chunk_space -= (stripe_size *
-                                                  map->num_stripes);
-       spin_unlock(&extent_root->fs_info->free_chunk_lock);
-
        stripe = &chunk->stripe;
        for (i = 0; i < map->num_stripes; i++) {
                device = map->stripes[i].dev;