Re: [PATCH] libnvdimm, pmem: Fix memcpy_mcsafe() return code handling in nsio_rw_bytes()

From: Vishal Verma
Date: Mon Jun 18 2018 - 15:13:01 EST


On 06/18, Dan Williams wrote:
> Commit 60622d68227d "x86/asm/memcpy_mcsafe: Return bytes remaining"
> converted callers of memcpy_mcsafe() to expect a positive 'bytes
> remaining' value rather than a negative error code. The nsio_rw_bytes()
> conversion failed to return success. The failure is benign in that
> nsio_rw_bytes() will end up writing back what it just read.
>
> Fixes: 60622d68227d ("x86/asm/memcpy_mcsafe: Return bytes remaining")
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
> drivers/nvdimm/claim.c | 1 +
> 1 file changed, 1 insertion(+)

Ah good catch. Looks good to me.
Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>

>
> diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
> index 2e96b34bc936..fb667bf469c7 100644
> --- a/drivers/nvdimm/claim.c
> +++ b/drivers/nvdimm/claim.c
> @@ -278,6 +278,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
> return -EIO;
> if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
> return -EIO;
> + return 0;
> }
>
> if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
>