On 2018/8/7 17:39, Junling Zheng wrote:
> Now we support crc32 checksum for superblock.
>
> Signed-off-by: Junling Zheng <[email protected]>
> ---
> v1 -> v1:
> - fix to switch endian of crc.
> fs/f2fs/f2fs.h | 1 +
> fs/f2fs/super.c | 28 ++++++++++++++++++++++++++++
> include/linux/f2fs_fs.h | 3 ++-
> 3 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 4525f4f82af0..d404ede01fcd 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -147,6 +147,7 @@ struct f2fs_mount_info {
> #define F2FS_FEATURE_INODE_CRTIME 0x0100
> #define F2FS_FEATURE_LOST_FOUND 0x0200
> #define F2FS_FEATURE_VERITY 0x0400 /* reserved */
> +#define F2FS_FEATURE_SB_CHKSUM 0x0800
Need to adjust sysfs entry for this new feature.
>
> #define F2FS_HAS_FEATURE(sb, mask) \
> ((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index bd57be470e23..c782fab52a12 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2149,6 +2149,8 @@ static int sanity_check_raw_super(struct f2fs_sb_info
> *sbi,
> (bh->b_data + F2FS_SUPER_OFFSET);
> struct super_block *sb = sbi->sb;
> unsigned int blocksize;
> + size_t crc_offset = 0;
> + __u32 crc = 0;
>
> if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
> f2fs_msg(sb, KERN_INFO,
> @@ -2283,6 +2285,23 @@ static int sanity_check_raw_super(struct f2fs_sb_info
> *sbi,
> if (sanity_check_area_boundary(sbi, bh))
> return 1;
>
> + if (F2FS_HAS_FEATURE(sbi->sb, F2FS_FEATURE_SB_CHKSUM)) {
> + crc_offset = le32_to_cpu(raw_super->checksum_offset);
> + if (crc_offset !=
> + offsetof(struct f2fs_super_block, crc)) {
> + f2fs_msg(sb, KERN_INFO,
> + "Invalid SB checksum offset: %lu",
> + crc_offset);
> + return 1;
> + }
> + crc = le32_to_cpu(raw_super->crc);
> + if (!f2fs_crc_valid(sbi, crc, raw_super, crc_offset)) {
> + f2fs_msg(sb, KERN_INFO,
> + "Invalid SB checksum value: %u", crc);
> + return 1;
> + }
> + }
How about moving above codes to the beginning of sanity_check_raw_super(), since
once crc value is wrong, all other verification is unneeded.
Thanks,
> +
> return 0;
> }
>
> @@ -2568,6 +2587,7 @@ static int read_raw_super_block(struct f2fs_sb_info
> *sbi,
> int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
> {
> struct buffer_head *bh;
> + __u32 crc = 0;
> int err;
>
> if ((recover && f2fs_readonly(sbi->sb)) ||
> @@ -2576,6 +2596,14 @@ int f2fs_commit_super(struct f2fs_sb_info *sbi, bool
> recover)
> return -EROFS;
> }
>
> + /* we should update superblock crc here */
> + if (!recover &&
> + F2FS_HAS_FEATURE(sbi->sb, F2FS_FEATURE_SB_CHKSUM)) {
> + crc = f2fs_crc32(sbi, F2FS_RAW_SUPER(sbi),
> + offsetof(struct f2fs_super_block, crc));
> + F2FS_RAW_SUPER(sbi)->crc = cpu_to_le32(crc);
> + }
> +
> /* write back-up superblock first */
> bh = sb_bread(sbi->sb, sbi->valid_super_block ? 0 : 1);
> if (!bh)
> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> index f70f8ac9c4f4..aa4b586569c1 100644
> --- a/include/linux/f2fs_fs.h
> +++ b/include/linux/f2fs_fs.h
> @@ -112,7 +112,8 @@ struct f2fs_super_block {
> struct f2fs_device devs[MAX_DEVICES]; /* device list */
> __le32 qf_ino[F2FS_MAX_QUOTAS]; /* quota inode numbers */
> __u8 hot_ext_count; /* # of hot file extension */
> - __u8 reserved[314]; /* valid reserved region */
> + __u8 reserved[310]; /* valid reserved region */
> + __le32 crc; /* checksum of superblock */
> } __packed;
>
> /*
>
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