[PATCH 1/2] f2fs-tools: allow unfixed f2fs_checkpoint.checksum_offset

From: Chao Yu
Date: Mon Apr 22 2019 - 05:35:25 EST


Previously, f2fs_checkpoint.checksum_offset points fixed position of
f2fs_checkpoint structure:

"#define CP_CHKSUM_OFFSET 4092"

It is unnecessary, and it breaks the consecutiveness of nat and sit
bitmap stored across checkpoint park block and payload blocks.

This patch allows f2fs-tools to handle unfixed .checksum_offset.

In addition, for the case checksum value is stored in the middle of
checkpoint park, calculating checksum value with superposition method
like we did for inode_checksum.

In addition, using MAX_BITMAP_SIZE_IN_CKPT to clean up codes.

Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
fsck/fsck.c | 5 +++--
fsck/mount.c | 5 +++--
fsck/resize.c | 10 +++++-----
include/f2fs_fs.h | 1 +
lib/libf2fs.c | 14 ++++++++++++++
mkfs/f2fs_format.c | 16 +++++++---------
6 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/fsck/fsck.c b/fsck/fsck.c
index a17555c..7ecdee1 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -2056,8 +2056,9 @@ static void fix_checkpoint(struct f2fs_sb_info *sbi)
set_cp(valid_node_count, fsck->chk.valid_node_cnt);
set_cp(valid_inode_count, fsck->chk.valid_inode_cnt);

- crc = f2fs_cal_crc32(F2FS_SUPER_MAGIC, cp, CP_CHKSUM_OFFSET);
- *((__le32 *)((unsigned char *)cp + CP_CHKSUM_OFFSET)) = cpu_to_le32(crc);
+ crc = f2fs_checkpoint_chksum(cp);
+ *((__le32 *)((unsigned char *)cp + get_cp(checksum_offset))) =
+ cpu_to_le32(crc);

cp_blk_no = get_sb(cp_blkaddr);
if (sbi->cur_cp == 2)
diff --git a/fsck/mount.c b/fsck/mount.c
index aa64e93..da1d4c9 100644
--- a/fsck/mount.c
+++ b/fsck/mount.c
@@ -2373,8 +2373,9 @@ void write_checkpoint(struct f2fs_sb_info *sbi)
flags = update_nat_bits_flags(sb, cp, flags);
set_cp(ckpt_flags, flags);

- crc = f2fs_cal_crc32(F2FS_SUPER_MAGIC, cp, CP_CHKSUM_OFFSET);
- *((__le32 *)((unsigned char *)cp + CP_CHKSUM_OFFSET)) = cpu_to_le32(crc);
+ crc = f2fs_checkpoint_chksum(cp);
+ *((__le32 *)((unsigned char *)cp + get_cp(checksum_offset))) =
+ cpu_to_le32(crc);

cp_blk_no = get_sb(cp_blkaddr);
if (sbi->cur_cp == 2)
diff --git a/fsck/resize.c b/fsck/resize.c
index 56c8103..2c623c5 100644
--- a/fsck/resize.c
+++ b/fsck/resize.c
@@ -90,11 +90,11 @@ static int get_new_sb(struct f2fs_super_block *sb)
* It requires more pages for cp.
*/
if (max_sit_bitmap_size > MAX_SIT_BITMAP_SIZE_IN_CKPT) {
- max_nat_bitmap_size = CP_CHKSUM_OFFSET - sizeof(struct f2fs_checkpoint) + 1;
+ max_nat_bitmap_size = MAX_BITMAP_SIZE_IN_CKPT;
set_sb(cp_payload, F2FS_BLK_ALIGN(max_sit_bitmap_size));
} else {
- max_nat_bitmap_size = CP_CHKSUM_OFFSET - sizeof(struct f2fs_checkpoint) + 1
- - max_sit_bitmap_size;
+ max_nat_bitmap_size = MAX_BITMAP_SIZE_IN_CKPT -
+ max_sit_bitmap_size;
set_sb(cp_payload, 0);
}

@@ -520,8 +520,8 @@ static void rebuild_checkpoint(struct f2fs_sb_info *sbi,
(unsigned char *)cp);
new_cp->checkpoint_ver = cpu_to_le64(cp_ver + 1);

- crc = f2fs_cal_crc32(F2FS_SUPER_MAGIC, new_cp, CP_CHKSUM_OFFSET);
- *((__le32 *)((unsigned char *)new_cp + CP_CHKSUM_OFFSET)) =
+ crc = f2fs_checkpoint_chksum(cp);
+ *((__le32 *)((unsigned char *)new_cp + get_cp(checksum_offset))) =
cpu_to_le32(crc);

/* Write a new checkpoint in the other set */
diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
index c6669c9..1bd935c 100644
--- a/include/f2fs_fs.h
+++ b/include/f2fs_fs.h
@@ -1133,6 +1133,7 @@ extern int utf16_to_utf8(char *, const u_int16_t *, size_t, size_t);
extern int log_base_2(u_int32_t);
extern unsigned int addrs_per_inode(struct f2fs_inode *);
extern __u32 f2fs_inode_chksum(struct f2fs_node *);
+extern __u32 f2fs_checkpoint_chksum(struct f2fs_checkpoint *);

extern int get_bits_in_byte(unsigned char n);
extern int test_and_set_bit_le(u32, u8 *);
diff --git a/lib/libf2fs.c b/lib/libf2fs.c
index 853e713..4202cd1 100644
--- a/lib/libf2fs.c
+++ b/lib/libf2fs.c
@@ -532,6 +532,20 @@ __u32 f2fs_inode_chksum(struct f2fs_node *node)
return chksum;
}

+__u32 f2fs_checkpoint_chksum(struct f2fs_checkpoint *cp)
+{
+ unsigned int chksum_ofs = le32_to_cpu(cp->checksum_offset);
+ __u32 chksum;
+
+ chksum = f2fs_cal_crc32(F2FS_SUPER_MAGIC, cp, chksum_ofs);
+ if (chksum_ofs < CP_CHKSUM_OFFSET) {
+ chksum_ofs += sizeof(chksum);
+ chksum = f2fs_cal_crc32(chksum, (__u8 *)cp + chksum_ofs,
+ F2FS_BLKSIZE - chksum_ofs);
+ }
+ return chksum;
+}
+
/*
* try to identify the root device
*/
diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index 4560611..a534293 100644
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -358,13 +358,11 @@ static int f2fs_prepare_super_block(void)
* It requires more pages for cp.
*/
if (max_sit_bitmap_size > MAX_SIT_BITMAP_SIZE_IN_CKPT) {
- max_nat_bitmap_size = CP_CHKSUM_OFFSET -
- sizeof(struct f2fs_checkpoint) + 1;
+ max_nat_bitmap_size = MAX_BITMAP_SIZE_IN_CKPT;
set_sb(cp_payload, F2FS_BLK_ALIGN(max_sit_bitmap_size));
} else {
- max_nat_bitmap_size =
- CP_CHKSUM_OFFSET - sizeof(struct f2fs_checkpoint) + 1
- - max_sit_bitmap_size;
+ max_nat_bitmap_size = MAX_BITMAP_SIZE_IN_CKPT -
+ max_sit_bitmap_size;
set_sb(cp_payload, 0);
}
max_nat_segments = (max_nat_bitmap_size * 8) >> log_blks_per_seg;
@@ -710,8 +708,8 @@ static int f2fs_write_check_point_pack(void)

set_cp(checksum_offset, CP_CHKSUM_OFFSET);

- crc = f2fs_cal_crc32(F2FS_SUPER_MAGIC, cp, CP_CHKSUM_OFFSET);
- *((__le32 *)((unsigned char *)cp + CP_CHKSUM_OFFSET)) =
+ crc = f2fs_checkpoint_chksum(cp);
+ *((__le32 *)((unsigned char *)cp + get_cp(checksum_offset))) =
cpu_to_le32(crc);

blk_size_bytes = 1 << get_sb(log_blocksize);
@@ -956,8 +954,8 @@ static int f2fs_write_check_point_pack(void)
*/
cp->checkpoint_ver = 0;

- crc = f2fs_cal_crc32(F2FS_SUPER_MAGIC, cp, CP_CHKSUM_OFFSET);
- *((__le32 *)((unsigned char *)cp + CP_CHKSUM_OFFSET)) =
+ crc = f2fs_checkpoint_chksum(cp);
+ *((__le32 *)((unsigned char *)cp + get_cp(checksum_offset))) =
cpu_to_le32(crc);
cp_seg_blk = get_sb(segment0_blkaddr) + c.blks_per_seg;
DBG(1, "\tWriting cp page 1 of checkpoint pack 2, at offset 0x%08"PRIx64"\n",
--
2.18.0.rc1