f2fs: fix crc endian conversion

While calculating CRC for the checkpoint block, we use __u32, but when storing
the crc value to the disk, we use __le32.

Let's fix the inconsistency.

Reported-and-Tested-by: Oded Gabbay <ogabbay@advaoptical.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 9a77509..66a6b85 100644 (file)
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -357,8 +357,8 @@ static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
        unsigned long blk_size = sbi->blocksize;
        struct f2fs_checkpoint *cp_block;
        unsigned long long cur_version = 0, pre_version = 0;
-       unsigned int crc = 0;
        size_t crc_offset;
+       __u32 crc = 0;
 
        /* Read the 1st cp block in this CP pack */
        cp_page_1 = get_meta_page(sbi, cp_addr);
@@ -369,7 +369,7 @@ static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
        if (crc_offset >= blk_size)
                goto invalid_cp1;
 
-       crc = *(unsigned int *)((unsigned char *)cp_block + crc_offset);
+       crc = le32_to_cpu(*((__u32 *)((unsigned char *)cp_block + crc_offset)));
        if (!f2fs_crc_valid(crc, cp_block, crc_offset))
                goto invalid_cp1;
 
@@ -384,7 +384,7 @@ static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
        if (crc_offset >= blk_size)
                goto invalid_cp2;
 
-       crc = *(unsigned int *)((unsigned char *)cp_block + crc_offset);
+       crc = le32_to_cpu(*((__u32 *)((unsigned char *)cp_block + crc_offset)));
        if (!f2fs_crc_valid(crc, cp_block, crc_offset))
                goto invalid_cp2;
 
@@ -648,7 +648,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
        block_t start_blk;
        struct page *cp_page;
        unsigned int data_sum_blocks, orphan_blocks;
-       unsigned int crc32 = 0;
+       __u32 crc32 = 0;
        void *kaddr;
        int i;
 
@@ -717,8 +717,8 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
        get_nat_bitmap(sbi, __bitmap_ptr(sbi, NAT_BITMAP));
 
        crc32 = f2fs_crc32(ckpt, le32_to_cpu(ckpt->checksum_offset));
-       *(__le32 *)((unsigned char *)ckpt +
-                               le32_to_cpu(ckpt->checksum_offset))
+       *((__le32 *)((unsigned char *)ckpt +
+                               le32_to_cpu(ckpt->checksum_offset)))
                                = cpu_to_le32(crc32);
 
        start_blk = __start_cp_addr(sbi);

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 863a5e9..467d42d 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -47,14 +47,25 @@ struct f2fs_mount_info {
        unsigned int    opt;
 };
 
-static inline __u32 f2fs_crc32(void *buff, size_t len)
+#define CRCPOLY_LE 0xedb88320
+
+static inline __u32 f2fs_crc32(void *buf, size_t len)
 {
-       return crc32_le(F2FS_SUPER_MAGIC, buff, len);
+       unsigned char *p = (unsigned char *)buf;
+       __u32 crc = F2FS_SUPER_MAGIC;
+       int i;
+
+       while (len--) {
+               crc ^= *p++;
+               for (i = 0; i < 8; i++)
+                       crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
+       }
+       return crc;
 }
 
-static inline bool f2fs_crc_valid(__u32 blk_crc, void *buff, size_t buff_size)
+static inline bool f2fs_crc_valid(__u32 blk_crc, void *buf, size_t buf_size)
 {
-       return f2fs_crc32(buff, buff_size) == blk_crc;
+       return f2fs_crc32(buf, buf_size) == blk_crc;
 }
 
 /*