From 1ccbad9f9f9bd36db26a10f0b17fbaf12b3ae93a Mon Sep 17 00:00:00 2001 From: Peng Tao Date: Thu, 9 Apr 2015 23:02:16 +0800 Subject: [PATCH] nfs: fix DIO good bytes calculation 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 Cc: # v3.19+ Signed-off-by: Peng Tao Signed-off-by: Trond Myklebust --- 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 018a06a..e97a67e 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; + } } /* -- 2.7.4