On 2019/7/31 7:18, Jaegeuk Kim wrote:
> 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;
> }
Um, I thought .required_features are used to store new feature flags from 0x0.
All 'F2FS_FEATURE_SUPPORT' bits should be stored in sb.feature instead of
sb.required_features, I'm confused...
Thanks,
>
>
>> + ~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
> .
>
