On 2020/4/21 上午8:25, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the btrfs tree, today's linux-next build (x86_64
> allmodconfig) failed like this:
> 
> In file included from <command-line>:32:

Any extra info?

It builds fine in my environment, with older HEAD though.

Is there any new commits which changed <linux/types.h> header?
As it should includes u8 typedef.

Thanks,
Qu

> ./usr/include/linux/btrfs_tree.h:1127:2: error: unknown type name 'u8'
>  1127 |  u8 tree_root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1128:2: error: unknown type name 'u8'
>  1128 |  u8 chunk_root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1129:2: error: unknown type name 'u8'
>  1129 |  u8 extent_root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1130:2: error: unknown type name 'u8'
>  1130 |  u8 fs_root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1131:2: error: unknown type name 'u8'
>  1131 |  u8 dev_root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1132:2: error: unknown type name 'u8'
>  1132 |  u8 csum_root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1134:2: error: unknown type name 'u8'
>  1134 |  u8 unused_8[10];
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1148:2: error: unknown type name 'u8'
>  1148 |  u8 csum[BTRFS_CSUM_SIZE];
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1150:2: error: unknown type name 'u8'
>  1150 |  u8 fsid[BTRFS_FSID_SIZE];
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1177:2: error: unknown type name 'u8'
>  1177 |  u8 root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1178:2: error: unknown type name 'u8'
>  1178 |  u8 chunk_root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1179:2: error: unknown type name 'u8'
>  1179 |  u8 log_root_level;
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1188:2: error: unknown type name 'u8'
>  1188 |  u8 metadata_uuid[BTRFS_FSID_SIZE];
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1192:2: error: unknown type name 'u8'
>  1192 |  u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1283:2: error: unknown type name 'u8'
>  1283 |  u8 csum[BTRFS_CSUM_SIZE];
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1284:2: error: unknown type name 'u8'
>  1284 |  u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1289:2: error: unknown type name 'u8'
>  1289 |  u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
>       |  ^~
> ./usr/include/linux/btrfs_tree.h:1293:2: error: unknown type name 'u8'
>  1293 |  u8 level;
>       |  ^~
> 
> Caused by commit
> 
>   8d80a063d508 ("btrfs: move on-disk structure definitions to btrfs_tree.h")
> 
> They should probably all be __u8 ...
> 
> I have applied the following patch for today.
> 
> From: Stephen Rothwell <sfr@canb.auug.org.au>
> Date: Tue, 21 Apr 2020 10:19:20 +1000
> Subject: [PATCH] btrfs: uapi headers should use __<type>
> 
> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
> ---
>  include/uapi/linux/btrfs_tree.h | 36 ++++++++++++++++-----------------
>  1 file changed, 18 insertions(+), 18 deletions(-)
> 
> diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
> index a02318e4d2a9..1adf5971a966 100644
> --- a/include/uapi/linux/btrfs_tree.h
> +++ b/include/uapi/linux/btrfs_tree.h
> @@ -1124,14 +1124,14 @@ struct btrfs_root_backup {
>  	/* future */
>  	__le64 unused_64[4];
>  
> -	u8 tree_root_level;
> -	u8 chunk_root_level;
> -	u8 extent_root_level;
> -	u8 fs_root_level;
> -	u8 dev_root_level;
> -	u8 csum_root_level;
> +	__u8 tree_root_level;
> +	__u8 chunk_root_level;
> +	__u8 extent_root_level;
> +	__u8 fs_root_level;
> +	__u8 dev_root_level;
> +	__u8 csum_root_level;
>  	/* future and to align */
> -	u8 unused_8[10];
> +	__u8 unused_8[10];
>  } __attribute__ ((__packed__));
>  
>  /*
> @@ -1145,9 +1145,9 @@ struct btrfs_root_backup {
>  /* The super block basically lists the main trees of the FS. */
>  struct btrfs_super_block {
>  	/* The first 4 fields must match struct btrfs_header */
> -	u8 csum[BTRFS_CSUM_SIZE];
> +	__u8 csum[BTRFS_CSUM_SIZE];
>  	/* FS specific UUID, visible to user */
> -	u8 fsid[BTRFS_FSID_SIZE];
> +	__u8 fsid[BTRFS_FSID_SIZE];
>  	__le64 bytenr; /* this block number */
>  	__le64 flags;
>  
> @@ -1174,9 +1174,9 @@ struct btrfs_super_block {
>  	__le64 compat_ro_flags;
>  	__le64 incompat_flags;
>  	__le16 csum_type;
> -	u8 root_level;
> -	u8 chunk_root_level;
> -	u8 log_root_level;
> +	__u8 root_level;
> +	__u8 chunk_root_level;
> +	__u8 log_root_level;
>  	struct btrfs_dev_item dev_item;
>  
>  	char label[BTRFS_LABEL_SIZE];
> @@ -1185,11 +1185,11 @@ struct btrfs_super_block {
>  	__le64 uuid_tree_generation;
>  
>  	/* The UUID written into btree blocks */
> -	u8 metadata_uuid[BTRFS_FSID_SIZE];
> +	__u8 metadata_uuid[BTRFS_FSID_SIZE];
>  
>  	/* Future expansion */
>  	__le64 reserved[28];
> -	u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
> +	__u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
>  	struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
>  } __attribute__ ((__packed__));
>  
> @@ -1280,17 +1280,17 @@ struct btrfs_super_block {
>  /* Every tree block (leaf or node) starts with this header. */
>  struct btrfs_header {
>  	/* These first four must match the super block */
> -	u8 csum[BTRFS_CSUM_SIZE];
> -	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
> +	__u8 csum[BTRFS_CSUM_SIZE];
> +	__u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
>  	__le64 bytenr; /* Which block this node is supposed to live in */
>  	__le64 flags;
>  
>  	/* Allowed to be different from the super from here on down. */
> -	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
> +	__u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
>  	__le64 generation;
>  	__le64 owner;
>  	__le32 nritems;
> -	u8 level;
> +	__u8 level;
>  } __attribute__ ((__packed__));
>  
>  /*
>