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authorPeng Tao <tao.peng@primarydata.com>2015-01-19 12:41:16 +0800
committerTom Haynes <loghyr@primarydata.com>2015-02-03 11:06:52 -0800
commit5fadeb47dcc5c30d4b6cf481b4a78689eab59443 (patch)
tree61144dbb7c04d5ddae49174c122ef1c686712b06 /fs/nfs/direct.c
parentaa8a45ee974dfe3ffe290daaf5db457afae56fde (diff)
nfs: count DIO good bytes correctly with mirroring
When resending to MDS, we might resend multiple mirroring requests to MDS. As a result, nfs_direct_good_bytes() ends up counting bytes multiple times, causing application to get wrong return results in read/write syscalls. Fix it by tracking start of a dreq and checking the range of pgio header. Cc: Weston Andros Adamson <dros@primarydata.com> Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Diffstat (limited to 'fs/nfs/direct.c')
-rw-r--r--fs/nfs/direct.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 4fad6b727eb4..3715b4957abc 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -88,6 +88,7 @@ struct nfs_direct_req {
ssize_t count, /* bytes actually processed */
bytes_left, /* bytes left to be sent */
+ io_start, /* start of IO */
error; /* any reported error */
struct completion completion; /* wait for i/o completion */
@@ -130,10 +131,11 @@ nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr)
WARN_ON_ONCE(hdr->pgio_mirror_idx >= dreq->mirror_count);
- dreq->mirrors[hdr->pgio_mirror_idx].count += hdr->good_bytes;
-
- if (hdr->pgio_mirror_idx == 0)
- dreq->count += hdr->good_bytes;
+ 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 */
@@ -594,6 +596,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
dreq->inode = inode;
dreq->bytes_left = count;
+ dreq->io_start = pos;
dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
l_ctx = nfs_get_lock_context(dreq->ctx);
if (IS_ERR(l_ctx)) {
@@ -1002,6 +1005,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
dreq->inode = inode;
dreq->bytes_left = count;
+ dreq->io_start = pos;
dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
l_ctx = nfs_get_lock_context(dreq->ctx);
if (IS_ERR(l_ctx)) {