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
>
> 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
> > .
> >
