On 2018年02月13日 11:00, Anand Jain wrote:
> Fixes the endianness bug in the fs_info::super_copy by using its
> btrfs_set_super...() function to set values in the SB, as these
> functions manage the endianness compatibility nicely.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>

Also went through all btrfs_super_block SETGET functions, greping using
\><member name>, seems that there are still some left here:

fs/btrfs/sysfs.c:
In both btrfs_sectorsize_show() and btrfs_clone_alignment_show():
	return snprintf(buf, PAGE_SIZE, "%u\n",
			fs_info->super_copy->sectorsize);

In btrfs_nodesize_show():
	return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);


And what about cc this to stable kernel?
IIRC it's a very critical problem for btrfs.

Maybe cc: stable@vger.kernel.org # v3.2+?

Thanks,
Qu

> ---
> v1->v2: Update change log. Update $Subject.
>         Old:
>         [PATCH] btrfs: use set functions to update latest refs to the SB
>  fs/btrfs/transaction.c | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
> index 04f07144b45c..9220f004001c 100644
> --- a/fs/btrfs/transaction.c
> +++ b/fs/btrfs/transaction.c
> @@ -1722,19 +1722,23 @@ static void update_super_roots(struct btrfs_fs_info *fs_info)
>  
>  	super = fs_info->super_copy;
>  
> +	/* update latest btrfs_super_block::chunk_root refs */
>  	root_item = &fs_info->chunk_root->root_item;
> -	super->chunk_root = root_item->bytenr;
> -	super->chunk_root_generation = root_item->generation;
> -	super->chunk_root_level = root_item->level;
> +	btrfs_set_super_chunk_root(super, root_item->bytenr);
> +	btrfs_set_super_chunk_root_generation(super, root_item->generation);
> +	btrfs_set_super_chunk_root_level(super, root_item->level);
>  
> +	/* update latest btrfs_super_block::root refs */
>  	root_item = &fs_info->tree_root->root_item;
> -	super->root = root_item->bytenr;
> -	super->generation = root_item->generation;
> -	super->root_level = root_item->level;
> +	btrfs_set_super_root(super, root_item->bytenr);
> +	btrfs_set_super_generation(super, root_item->generation);
> +	btrfs_set_super_root_level(super, root_item->level);
> +
>  	if (btrfs_test_opt(fs_info, SPACE_CACHE))
> -		super->cache_generation = root_item->generation;
> +		btrfs_set_super_cache_generation(super, root_item->generation);
>  	if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags))
> -		super->uuid_tree_generation = root_item->generation;
> +		btrfs_set_super_uuid_tree_generation(super,
> +						     root_item->generation);
>  }
>  
>  int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
>