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 > > 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 > >>> . > >>> > > . > >