Re: [f2fs-dev] [RFC PATCH v4 1/3] f2fs: support superblock checksum

2018-08-08 Thread Chao Yu
On 2018/8/8 20:54, Junling Zheng wrote:
> Now we support crc32 checksum for superblock.
> 
> Signed-off-by: Junling Zheng 

Reviewed-by: Chao Yu 

Thanks,

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[f2fs-dev] [RFC PATCH v4 1/3] f2fs: support superblock checksum

2018-08-08 Thread Junling Zheng
Now we support crc32 checksum for superblock.

Signed-off-by: Junling Zheng 
---
v3 -> v4:
 - use '%zu' for size_t to fix compile warning.
 - use f2fs_sb_has_sb_chksum() instead of F2FS_HAS_FEATURE().
v2 -> v3:
 - add sysfs entry for superblock checksum.
 - move the crc checking to the beginning of sanity_check_raw_super().
 - fix the NULL pointer dereference as sb->s_fs_info hasn't be set yet in
   sanity_check_raw_super().
v1 -> v2:
 - fix to switch endian of crc.
 fs/f2fs/f2fs.h  |  2 ++
 fs/f2fs/super.c | 29 +
 fs/f2fs/sysfs.c |  7 +++
 include/linux/f2fs_fs.h |  3 ++-
 4 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 4525f4f82af0..d50d6efda96b 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_FOUND0x0200
 #define F2FS_FEATURE_VERITY0x0400  /* reserved */
+#define F2FS_FEATURE_SB_CHKSUM 0x0800
 
 #define F2FS_HAS_FEATURE(sb, mask) \
((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)
@@ -3376,6 +3377,7 @@ F2FS_FEATURE_FUNCS(flexible_inline_xattr, 
FLEXIBLE_INLINE_XATTR);
 F2FS_FEATURE_FUNCS(quota_ino, QUOTA_INO);
 F2FS_FEATURE_FUNCS(inode_crtime, INODE_CRTIME);
 F2FS_FEATURE_FUNCS(lost_found, LOST_FOUND);
+F2FS_FEATURE_FUNCS(sb_chksum, SB_CHKSUM);
 
 #ifdef CONFIG_BLK_DEV_ZONED
 static inline int get_blkz_type(struct f2fs_sb_info *sbi,
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index bd57be470e23..3ffc336caea8 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2149,6 +2149,26 @@ 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;
+
+   /* Check checksum_offset and crc in superblock */
+   if (le32_to_cpu(raw_super->feature) & 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: %zu",
+   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;
+   }
+   }
 
if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
f2fs_msg(sb, KERN_INFO,
@@ -2568,6 +2588,7 @@ 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 +2597,14 @@ int f2fs_commit_super(struct f2fs_sb_info *sbi, bool 
recover)
return -EROFS;
}
 
+   /* we should update superblock crc here */
+   if (!recover &&
+   f2fs_sb_has_sb_chksum(sbi->sb)) {
+   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/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index cd2e030e47b8..c86d91be6c48 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -120,6 +120,9 @@ static ssize_t features_show(struct f2fs_attr *a,
if (f2fs_sb_has_lost_found(sb))
len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
len ? ", " : "", "lost_found");
+   if (f2fs_sb_has_sb_chksum(sb))
+   len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+   len ? ", " : "", "sb_checksum");
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
return len;
 }
@@ -337,6 +340,7 @@ enum feat_id {
FEAT_QUOTA_INO,
FEAT_INODE_CRTIME,
FEAT_LOST_FOUND,
+   FEAT_SB_CHECKSUM,
 };
 
 static ssize_t f2fs_feature_show(struct f2fs_attr *a,
@@ -353,6 +357,7 @@ static ssize_t f2fs_feature_show(struct f2fs_attr *a,
case FEAT_QUOTA_INO:
case FEAT_INODE_CRTIME:
case FEAT_LOST_FOUND:
+   case FEAT_SB_CHECKSUM:
return snprintf(buf, PAGE_SIZE, "supported\n");
}
return 0;
@@ -433,6 +438,7 @@ F2FS_FEATURE_RO_ATTR(flexible_inline_xattr, 
FEAT_FLEXIBLE_INLINE_XATTR);