On 10.04.19 г. 11:35 ч., Qu Wenruo wrote:
> There are quite a lot of filesystems doing their verification work done
> at endio hook or hook before submitting bio.
>
> Normally such verification returns -EUCLEAN/-EFSCORRUPTED to indicate
> something unexpected, and some of such verification either use> bio->bi_status or users bio->bi_endio to return their value.
Usually filesystems return -EUCLEAN/-EFSCORRUPTED to indicate failed
verification. Currently there is no strict way how this information is
communicated - either via bio->bi_status or through the bio's endio
return value.
>
> In such case, the missing of corresponding BLK_STS_ bit can lower
> the severity just like:
>
> In endio function:
> return errno_to_blk_status(-EFSCORRUPTED);
> ^^^ -EFSCORRUPTED gets interpreted to BLK_STS_IOERR
>
> In the filesystem code:
> ret = blk_status_to_errno(bi->bi_status);
> ^^^ BLK_STS_IOERR gets interpreted to -EIO;
>
> This lowers the severity, making the filesystem layer to believe it's
> just an ordinary error.
>
> This patch will add a new BLK_STS_FSCORRUPTED, to allow -EFSCORRUPTED to
> be converted to BLK_STS_FSCORRUPTED, and then converted back to
> -EFSCORRUPTED without losing info.
This patch will add a new BLK_STS_FSCORRUPTED block status code,
allowing filesystem corruptions to be properly communicated to upper
layers.
>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
> ---
> block/blk-core.c | 1 +
> include/linux/blk_types.h | 3 +++
> 2 files changed, 4 insertions(+)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index a55389ba8779..ba7acfc3d8e0 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -135,6 +135,7 @@ static const struct {
> [BLK_STS_RESOURCE] = { -ENOMEM, "kernel resource" },
> [BLK_STS_DEV_RESOURCE] = { -EBUSY, "device resource" },
> [BLK_STS_AGAIN] = { -EAGAIN, "nonblocking retry" },
> + [BLK_STS_FSCORRUPTED] = { -EFSCORRUPTED, "filesystem is corrupted" },
>
> /* device mapper special case, should not leak out: */
> [BLK_STS_DM_REQUEUE] = { -EREMCHG, "dm internal retry" },
> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
> index 791fee35df88..8f70bbec6c83 100644
> --- a/include/linux/blk_types.h
> +++ b/include/linux/blk_types.h
> @@ -63,6 +63,9 @@ typedef u8 __bitwise blk_status_t;
> */
> #define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13)
>
> +/* Normally filesystem layer generated error */
> +#define BLK_STS_FSCORRUPTED ((__force blk_status_t)14)
> +
> /**
> * blk_path_error - returns true if error may be path related
> * @error: status the request was completed with
>
