Re: [PATCH 1/4] btrfs-progs: Limit inline extent below page size

[Nikolay Borisov <n.borisov.lkml@gmail.com>]

On  1.03.2018 04:47, Qu Wenruo wrote:
> Kernel doesn't support to drop extent inside an inlined extent.
> And kernel tends to limit inline extent just below sectorsize, so also
> limit it in btrfs-progs.
> 
> This fixes unexpected -EOPNOTSUPP error from __btrfs_drop_extents() on
> converted btrfs.
> 
> Fixes: 806528b8755f ("Add Yan Zheng's ext3->btrfs conversion program")
> Reported-by: Peter Y. Chuang <peteryuchuang@gmail.com>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  ctree.h | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/ctree.h b/ctree.h
> index 17cdac76c58c..0282deef339b 100644
> --- a/ctree.h
> +++ b/ctree.h
> @@ -20,6 +20,7 @@
>  #define __BTRFS_CTREE_H__
>  
>  #include <stdbool.h>
> +#include "internal.h"
>  
>  #if BTRFS_FLAT_INCLUDES
>  #include "list.h"
> @@ -1195,8 +1196,14 @@ static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
>  	(offsetof(struct btrfs_file_extent_item, disk_bytenr))
>  static inline u32 BTRFS_MAX_INLINE_DATA_SIZE(const struct btrfs_fs_info *info)
>  {
> -	return BTRFS_MAX_ITEM_SIZE(info) -
> -		BTRFS_FILE_EXTENT_INLINE_DATA_START;
> +	/*
> +	 * Inline extent larger than pagesize could lead to kernel unexpected
> +	 * error when dropping extents, so we need to limit the inline extent
> +	 * size to less than sectorsize.
> +	 */
> +	return min_t(u32, info->sectorsize - 1,
> +		     BTRFS_MAX_ITEM_SIZE(info) -
> +		     BTRFS_FILE_EXTENT_INLINE_DATA_START);
>  }

Isn't the same change required in the kernel as well ?

>  
>  static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
>