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>

2 files changed, 21 insertions, 10 deletions

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 9a7750909221..66a6b85a51d8 100644
--- 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 863a5e91d84a..467d42d65c48 100644
--- 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;
 }
 
 /*