On 07/29, Chao Yu wrote:
> From: Chao Yu <yuch...@huawei.com>
>
> Later after this patch was merged, all new incompatible feature's
> bit should be added into sb.required_features field, and define new
> feature function with F2FS_INCOMPAT_FEATURE_FUNCS() macro.
>
> Then during mount, we will do sanity check with enabled features in
> image, if there are features in sb.required_features that kernel can
> not recognize, just fail the mount.
>
> Signed-off-by: Chao Yu <yuch...@huawei.com>
> ---
> v3:
> - change commit title.
> - fix wrong macro name.
> fs/f2fs/f2fs.h | 15 +++++++++++++++
> fs/f2fs/super.c | 10 ++++++++++
> include/linux/f2fs_fs.h | 3 ++-
> 3 files changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index a6eb828af57f..b8e17d4ddb8d 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -163,6 +163,15 @@ struct f2fs_mount_info {
> #define F2FS_CLEAR_FEATURE(sbi, mask)
> \
> (sbi->raw_super->feature &= ~cpu_to_le32(mask))
>
> +#define F2FS_INCOMPAT_FEATURES 0
> +
> +#define F2FS_HAS_INCOMPAT_FEATURE(sbi, mask) \
> + ((sbi->raw_super->required_features & cpu_to_le32(mask)) != 0)
> +#define F2FS_SET_INCOMPAT_FEATURE(sbi, mask) \
> + (sbi->raw_super->required_features |= cpu_to_le32(mask))
> +#define F2FS_CLEAR_INCOMPAT_FEATURE(sbi, mask)
> \
> + (sbi->raw_super->required_features &= ~cpu_to_le32(mask))
> +
> /*
> * Default values for user and/or group using reserved blocks
> */
> @@ -3585,6 +3594,12 @@ F2FS_FEATURE_FUNCS(lost_found, LOST_FOUND);
> F2FS_FEATURE_FUNCS(sb_chksum, SB_CHKSUM);
> F2FS_FEATURE_FUNCS(casefold, CASEFOLD);
>
> +#define F2FS_INCOMPAT_FEATURE_FUNCS(name, flagname) \
> +static inline int f2fs_sb_has_##name(struct f2fs_sb_info *sbi) \
> +{ \
> + return F2FS_HAS_INCOMPAT_FEATURE(sbi, F2FS_FEATURE_##flagname); \
> +}
> +
> #ifdef CONFIG_BLK_DEV_ZONED
> static inline bool f2fs_blkz_is_seq(struct f2fs_sb_info *sbi, int devi,
> block_t blkaddr)
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 5540fee0fe3f..3701dcce90e6 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2513,6 +2513,16 @@ static int sanity_check_raw_super(struct f2fs_sb_info
> *sbi,
> return -EINVAL;
> }
>
> + /* check whether current kernel supports all features on image */
> + if (le32_to_cpu(raw_super->required_features) &
...
#define F2FS_FEATURE_VERITY 0x0400 /* reserved */
...
#define F2FS_FEATURE_CASEFOLD 0x1000
#define F2FS_FEATURE_SUPPORT 0x1BFF
if (le32_to_cpu(raw_super->required_features) & ~F2FS_FEATURE_SUPPORT) {
...
return -EINVAL;
}
> + ~F2FS_INCOMPAT_FEATURES) {
> + f2fs_info(sbi, "Unsupported feature: %x: supported: %x",
> + le32_to_cpu(raw_super->required_features) ^
> + F2FS_INCOMPAT_FEATURES,
> + F2FS_INCOMPAT_FEATURES);
> + return -EINVAL;
> + }
> +
> /* Check checksum_offset and crc in superblock */
> if (__F2FS_HAS_FEATURE(raw_super, F2FS_FEATURE_SB_CHKSUM)) {
> crc_offset = le32_to_cpu(raw_super->checksum_offset);
> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> index a2b36b2e286f..4141be3f219c 100644
> --- a/include/linux/f2fs_fs.h
> +++ b/include/linux/f2fs_fs.h
> @@ -117,7 +117,8 @@ struct f2fs_super_block {
> __u8 hot_ext_count; /* # of hot file extension */
> __le16 s_encoding; /* Filename charset encoding */
> __le16 s_encoding_flags; /* Filename charset encoding flags */
> - __u8 reserved[306]; /* valid reserved region */
> + __le32 required_features; /* incompatible features to old kernel
> */
> + __u8 reserved[302]; /* valid reserved region */
> __le32 crc; /* checksum of superblock */
> } __packed;
>
> --
> 2.22.0
