On Thu, Apr 9, 2015 at 11:02 AM, Peng Tao <tao.peng@xxxxxxxxxxxxxxx> wrote:
> For direct read that has IO size larger than rsize, we'll split
> it into several READ requests and nfs_direct_good_bytes() would
> count completed bytes incorrectly by eating last zero count reply.
>
> Fix it by handling mirror and non-mirror cases differently such that
> we only count mirrored writes differently.
>
> This fixes 5fadeb47("nfs: count DIO good bytes correctly with mirroring").
>
> Reported-by: Jean Spector <jean@xxxxxxxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # v3.19+
> Signed-off-by: Peng Tao <tao.peng@xxxxxxxxxxxxxxx>
This one (and 2/2 in the series) have been setting here with no
comments for a while now. Are these going to get picked up for 4.1?
We have a couple of bug reports against 3.19 that these should fix, so
I'm curious if they're headed in-tree.
josh
> ---
> fs/nfs/direct.c | 29 +++++++++++++++++------------
> 1 file changed, 17 insertions(+), 12 deletions(-)
>
> diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
> index e907c8c..5e451a7 100644
> --- a/fs/nfs/direct.c
> +++ b/fs/nfs/direct.c
> @@ -131,20 +131,25 @@ nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr)
>
> WARN_ON_ONCE(hdr->pgio_mirror_idx >= dreq->mirror_count);
>
> - count = dreq->mirrors[hdr->pgio_mirror_idx].count;
> - if (count + dreq->io_start < hdr->io_start + hdr->good_bytes) {
> - count = hdr->io_start + hdr->good_bytes - dreq->io_start;
> - dreq->mirrors[hdr->pgio_mirror_idx].count = count;
> - }
> -
> - /* update the dreq->count by finding the minimum agreed count from all
> - * mirrors */
> - count = dreq->mirrors[0].count;
> + if (dreq->mirror_count == 1) {
> + dreq->mirrors[hdr->pgio_mirror_idx].count += hdr->good_bytes;
> + dreq->count += hdr->good_bytes;
> + } else {
> + /* mirrored writes */
> + count = dreq->mirrors[hdr->pgio_mirror_idx].count;
> + if (count + dreq->io_start < hdr->io_start + hdr->good_bytes) {
> + count = hdr->io_start + hdr->good_bytes - dreq->io_start;
> + dreq->mirrors[hdr->pgio_mirror_idx].count = count;
> + }
> + /* update the dreq->count by finding the minimum agreed count from all
> + * mirrors */
> + count = dreq->mirrors[0].count;
>
> - for (i = 1; i < dreq->mirror_count; i++)
> - count = min(count, dreq->mirrors[i].count);
> + for (i = 1; i < dreq->mirror_count; i++)
> + count = min(count, dreq->mirrors[i].count);
>
> - dreq->count = count;
> + dreq->count = count;
> + }
> }
>
> /*
> --
> 1.9.1
>
> --
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