From: Miao Xie Date: Wed, 3 Sep 2014 13:35:39 +0000 (+0800) Subject: Btrfs: fix unprotected system chunk array insertion X-Git-Tag: firefly_0821_release~176^2~2834^2~52 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=fe48a5c00f3c8087fc0a447caee2b5f9f97cf238;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 41da102cdcc0..9f22398d465f 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4054,10 +4054,13 @@ static int btrfs_add_system_chunk(struct btrfs_root *root, 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 @@ static int btrfs_add_system_chunk(struct btrfs_root *root, 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; }