On 2019/8/2 6:35, Jaegeuk Kim wrote: > On 08/01, Chao Yu wrote: >> On 2019/8/1 12:22, Jaegeuk Kim wrote: >>> On 07/31, Chao Yu wrote: >>>> 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... >>> >>> I'm thinking, >>> >>> f2fs-tools sb->required_features f2fs F2FS_FEATURE_SUPPORT >>> v0 0 v0 no_check -> ok >>> v1 0x1BFF v0 no_check -> ok >>> v0 0 v1 0x1BFF -> ok >>> v1 0x1BFF v1 0x1BFF -> ok >>> v2 0x3BFF v1 0x1BFF -> fail >>> v1 0x1BFF v2 0x3BFF -> ok >>> v2 0x3BFF v2 0x3BFF -> ok >> >> I see, it's a bit waste for 0x1FFF low bits in sb->required_features. Why not >> leaving 0x0FFF in sb->feature w/o sanity check. And make all new incompatible >> features (including casefold) adding into sb->required_features. > > I don't think we can define like this, and we still have 32bits feature filed. > This would give another confusion to understand. VERITY is reserved only now. > > #define F2FS_FEATURE_CASEFOLD 0x0001
Oops, so you want to make .required_features being almost a mirror of .feature, and do sanity check on it... I can see now. :P If so, why not just use .feature: kernel tool v5.2 .. 1.12 #define F2FS_FEATURE_SUPPORT 0x0BFF v5.3 .. 1.13 #define F2FS_FEATURE_CASEFOLD 0x1000 #define F2FS_FEATURE_SUPPORT 0x1BFF v5.4 .. 1.14 #define F2FS_FEATURE_CASEFOLD 0x1000 #define F2FS_FEATURE_COMPRESS 0x2000 #define F2FS_FEATURE_SUPPORT 0x3BFF f2fs-tools sb->feature f2fs F2FS_FEATURE_SUPPORT [enable all features in tools] v1.12 0x0BFF v5.2 no_check -> ok v1.12 0x0BFF v5.3 0x1BFF -> ok v1.12 0x0BFF v5.4 0x3BFF -> ok v1.13 0x1BFF v5.2 that's issue we need to fix v1.13 0x1BFF v5.3 0x1BFF -> ok v1.13 0x1BFF v5.4 0x3BFF -> ok v1.14 0x3BFF v5.2 that's issue we need to fix v1.14 0x3BFF v5.3 0x1BFF -> fail v1.14 0x3BFF v5.4 0x3BFF -> ok Or am I missing something? Thanks, > >> >> Then that would be: >> >> kernel tool >> v5.2 .. 1.12 >> #define F2FS_FEATURE_SUPPORT 0x0000 >> >> v5.3 .. 1.13 >> #define F2FS_FEATURE_CASEFOLD 0x0001 >> #define F2FS_FEATURE_SUPPORT 0x0001 >> >> v5.4 .. 1.14 >> #define F2FS_FEATURE_CASEFOLD 0x0001 >> #define F2FS_FEATURE_COMPRESS 0x0002 >> #define F2FS_FEATURE_SUPPORT 0x0003 >> >> f2fs-tools sb->required_features f2fs F2FS_FEATURE_SUPPORT >> >> v1.12 0x0000 v5.2 no_check -> ok >> v1.12 0x0000 v5.3 0x0001 -> ok >> v1.12 0x0000 v5.4 0x0003 -> ok >> >> v1.13 0x0001 v5.2 that's issue we need to >> fix >> v1.13 0x0001 v5.3 0x0001 -> ok >> v1.13 0x0001 v5.4 0x0003 -> ok >> >> v1.14 0x0003 v5.2 that's issue we need to >> fix >> v1.14 0x0003 v5.3 0x0001 -> fail >> v1.14 0x0003 v5.4 0x0003 -> ok >> >> And all compatible features can be added into sb->feature[_VERITY, ....]. >> >> Would that okay to you? >> >> Thanks, >> >>> >>>> >>>> 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 >>>>> . >>>>> >>> . >>> > . >