[PATCH 4/5] f2fs-tools: introduce sb checksum

[Junling Zheng <zhengjunling@huawei.com>]

This patch introduced crc for superblock.

Signed-off-by: Junling Zheng <zhengjunling@huawei.com>
---
 fsck/mount.c       | 33 +++++++++++++++++++++++++++++++++
 fsck/resize.c      | 12 ++++++------
 include/f2fs_fs.h  |  6 +++++-
 mkfs/f2fs_format.c |  8 ++++++++
 4 files changed, 52 insertions(+), 7 deletions(-)

diff --git a/fsck/mount.c b/fsck/mount.c
index 74ff7c6..9019921 100644
--- a/fsck/mount.c
+++ b/fsck/mount.c
@@ -340,6 +340,7 @@ void print_raw_sb_info(struct f2fs_super_block *sb)
 	DISP_u32(sb, node_ino);
 	DISP_u32(sb, meta_ino);
 	DISP_u32(sb, cp_payload);
+	DISP_u32(sb, crc);
 	DISP("%-.256s", sb, version);
 	printf("\n");
 }
@@ -467,6 +468,9 @@ void print_sb_state(struct f2fs_super_block *sb)
 	if (f & cpu_to_le32(F2FS_FEATURE_LOST_FOUND)) {
 		MSG(0, "%s", " lost_found");
 	}
+	if (f & cpu_to_le32(F2FS_FEATURE_SB_CHKSUM)) {
+		MSG(0, "%s", " sb_checksum");
+	}
 	MSG(0, "\n");
 	MSG(0, "Info: superblock encrypt level = %d, salt = ",
 					sb->encryption_level);
@@ -479,10 +483,20 @@ void update_superblock(struct f2fs_super_block *sb, int sb_mask)
 {
 	int addr, ret;
 	u_int8_t *buf;
+	u32 old_crc, new_crc;
 
 	buf = calloc(BLOCK_SZ, 1);
 	ASSERT(buf);
 
+	if (get_sb(feature) & F2FS_FEATURE_SB_CHKSUM) {
+		old_crc = get_sb(crc);
+		new_crc = f2fs_cal_crc32(F2FS_SUPER_MAGIC, sb,
+						SB_CHKSUM_OFFSET);
+		set_sb(crc, new_crc);
+		MSG(1, "Info: SB CRC is updated (0x%x -> 0x%x)\n",
+							old_crc, new_crc);
+	}
+
 	memcpy(buf + F2FS_SUPER_OFFSET, sb, sizeof(*sb));
 	for (addr = SB0_ADDR; addr < SB_MAX_ADDR; addr++) {
 		if (SB_MASK(addr) & sb_mask) {
@@ -575,10 +589,29 @@ static inline int sanity_check_area_boundary(struct f2fs_super_block *sb,
 	return 0;
 }
 
+static int verify_sb_chksum(struct f2fs_super_block *sb)
+{
+	if (SB_CHKSUM_OFFSET != get_sb(checksum_offset)) {
+		MSG(0, "\tInvalid SB CRC offset: %u\n",
+					get_sb(checksum_offset));
+		return -1;
+	}
+	if (f2fs_crc_valid(get_sb(crc), sb,
+			get_sb(checksum_offset))) {
+		MSG(0, "\tInvalid SB CRC: 0x%x\n", get_sb(crc));
+		return -1;
+	}
+	return 0;
+}
+
 int sanity_check_raw_super(struct f2fs_super_block *sb, enum SB_ADDR sb_addr)
 {
 	unsigned int blocksize;
 
+	if ((get_sb(feature) & F2FS_FEATURE_SB_CHKSUM) &&
+					verify_sb_chksum(sb))
+		return -1;
+
 	if (F2FS_SUPER_MAGIC != get_sb(magic))
 		return -1;
 
diff --git a/fsck/resize.c b/fsck/resize.c
index 5161a1f..3462165 100644
--- a/fsck/resize.c
+++ b/fsck/resize.c
@@ -603,9 +603,6 @@ static int f2fs_resize_grow(struct f2fs_sb_info *sbi)
 		}
 	}
 
-	print_raw_sb_info(sb);
-	print_raw_sb_info(new_sb);
-
 	old_main_blkaddr = get_sb(main_blkaddr);
 	new_main_blkaddr = get_newsb(main_blkaddr);
 	offset = new_main_blkaddr - old_main_blkaddr;
@@ -629,6 +626,9 @@ static int f2fs_resize_grow(struct f2fs_sb_info *sbi)
 	migrate_sit(sbi, new_sb, offset_seg);
 	rebuild_checkpoint(sbi, new_sb, offset_seg);
 	update_superblock(new_sb, SB_MASK_ALL);
+	print_raw_sb_info(sb);
+	print_raw_sb_info(new_sb);
+
 	return 0;
 }
 
@@ -658,9 +658,6 @@ static int f2fs_resize_shrink(struct f2fs_sb_info *sbi)
 		}
 	}
 
-	print_raw_sb_info(sb);
-	print_raw_sb_info(new_sb);
-
 	old_main_blkaddr = get_sb(main_blkaddr);
 	new_main_blkaddr = get_newsb(main_blkaddr);
 	offset = old_main_blkaddr - new_main_blkaddr;
@@ -690,6 +687,9 @@ static int f2fs_resize_shrink(struct f2fs_sb_info *sbi)
 	/* move whole data region */
 	//if (err)
 	//	migrate_main(sbi, offset);
+	print_raw_sb_info(sb);
+	print_raw_sb_info(new_sb);
+
 	return 0;
 }
 
diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
index 38a0da4..f80632a 100644
--- a/include/f2fs_fs.h
+++ b/include/f2fs_fs.h
@@ -279,6 +279,7 @@ static inline uint64_t bswap_64(uint64_t val)
 #define BITS_PER_BYTE		8
 #define F2FS_SUPER_MAGIC	0xF2F52010	/* F2FS Magic Number */
 #define CP_CHKSUM_OFFSET	4092
+#define SB_CHKSUM_OFFSET	3068
 #define MAX_PATH_LEN		64
 #define MAX_DEVICES		8
 
@@ -579,6 +580,7 @@ enum {
 #define F2FS_FEATURE_INODE_CRTIME	0x0100
 #define F2FS_FEATURE_LOST_FOUND		0x0200
 #define F2FS_FEATURE_VERITY		0x0400	/* reserved */
+#define F2FS_FEATURE_SB_CHKSUM		0x0800
 
 #define MAX_VOLUME_NAME		512
 
@@ -632,7 +634,8 @@ 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 */
 } __attribute__((packed));
 
 /*
@@ -1338,6 +1341,7 @@ struct feature feature_table[] = {					\
 	{ "inode_crtime",		F2FS_FEATURE_INODE_CRTIME },	\
 	{ "lost_found",			F2FS_FEATURE_LOST_FOUND },	\
 	{ "verity",			F2FS_FEATURE_VERITY },	/* reserved */ \
+	{ "sb_checksum",		F2FS_FEATURE_SB_CHKSUM },	\
 	{ NULL,				0x0},				\
 };
 
diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index 621126c..9b0a0d1 100644
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -504,6 +504,14 @@ static int f2fs_prepare_super_block(void)
 
 	sb->feature = c.feature;
 
+	if (get_sb(feature) & F2FS_FEATURE_SB_CHKSUM) {
+		set_sb(checksum_offset, SB_CHKSUM_OFFSET);
+		set_sb(crc, f2fs_cal_crc32(F2FS_SUPER_MAGIC, sb,
+						SB_CHKSUM_OFFSET));
+		MSG(1, "Info: SB CRC is set: offset (%d), crc (0x%x)\n",
+					get_sb(checksum_offset), get_sb(crc));
+	}
+
 	return 0;
 }
 
-- 
2.19.0