On 02/06, Weichao Guo wrote:
> There is a potential inconsistent metadata case due to a cp block
> crc invalid in the latest checkpoint caused by hardware issues:
> 1) write nodes into segment x;
> 2) write checkpoint A;
> 3) remove nodes in segment x;
> 4) write checkpoint B;
> 5) issue discard or write datas into segment x;
> 6) sudden power-cut;
> 7) use checkpoint A after reboot as checkpoint B is invalid
> 
> This inconsistency may be found after several reboots long time later
> and the kernel log about cp block crc invalid has disappeared. This
> makes the root cause of the inconsistency is hard to locate. Let us
> separate such other part issues from f2fs logical bugs in debug version.
> 
> Signed-off-by: Weichao Guo <guoweic...@huawei.com>
> ---
>  fs/f2fs/checkpoint.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index 8b0945b..16ba96a 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -737,13 +737,17 @@ static int get_checkpoint_version(struct f2fs_sb_info 
> *sbi, block_t cp_addr,
>       crc_offset = le32_to_cpu((*cp_block)->checksum_offset);
>       if (crc_offset > (blk_size - sizeof(__le32))) {
>               f2fs_msg(sbi->sb, KERN_WARNING,
> -                     "invalid crc_offset: %zu", crc_offset);
> +                     "invalid crc_offset: %zu at blk_addr: 0x%x",
> +                             crc_offset, cp_addr);
> +             f2fs_bug_on(sbi, 1);

I don't think we can use bug_on here, since we're easily getting this when
power-cut happened in the middle of checkpoint pack writes, which is an expected
behavior. Hmm, we need to consider another way to detect that.

Thanks,

>               return -EINVAL;
>       }
>  
>       crc = cur_cp_crc(*cp_block);
>       if (!f2fs_crc_valid(sbi, crc, *cp_block, crc_offset)) {
> -             f2fs_msg(sbi->sb, KERN_WARNING, "invalid crc value");
> +             f2fs_msg(sbi->sb, KERN_WARNING,
> +                     "invalid crc value at blk_addr: 0x%x", cp_addr);
> +             f2fs_bug_on(sbi, 1);
>               return -EINVAL;
>       }
>  
> -- 
> 2.10.1

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