Btrfs: fix unprotected system chunk array insertion
We didn't protect the system chunk array when we added a new
system chunk into it, it would cause the array be corrupted
if someone remove/add some system chunk into array at the same
time. Fix it by chunk lock.
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 41da102..9f22398d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4054,10 +4054,13 @@
u32 array_size;
u8 *ptr;
+ lock_chunks(root);
array_size = btrfs_super_sys_array_size(super_copy);
if (array_size + item_size + sizeof(disk_key)
- > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
+ > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
+ unlock_chunks(root);
return -EFBIG;
+ }
ptr = super_copy->sys_chunk_array + array_size;
btrfs_cpu_key_to_disk(&disk_key, key);
@@ -4066,6 +4069,8 @@
memcpy(ptr, chunk, item_size);
item_size += sizeof(disk_key);
btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
+ unlock_chunks(root);
+
return 0;
}