NFSv41: fix DIO write_io calculation

pnfs_within_mdsthreshold() is called inside pg_init. We need to set
read_io/write_io before that. Otherwise we fail pnfs_within_mdsthreshold()
and IO goes to MDS.
A simple test case:
dd if=foo of=/mnt/pnfs/bar bs=10M count=1 oflag=direct

Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 22130df..253d397 100644 (file)
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -467,10 +467,10 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
        if (!is_sync_kiocb(iocb))
                dreq->iocb = iocb;
 
+       NFS_I(inode)->read_io += iov_length(iov, nr_segs);
        result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio);
        if (!result)
                result = nfs_direct_wait(dreq);
-       NFS_I(inode)->read_io += result;
 out_release:
        nfs_direct_req_release(dreq);
 out:
@@ -818,6 +818,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
        get_dreq(dreq);
        atomic_inc(&inode->i_dio_count);
 
+       NFS_I(dreq->inode)->write_io += iov_length(iov, nr_segs);
        for (seg = 0; seg < nr_segs; seg++) {
                const struct iovec *vec = &iov[seg];
                result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio);
@@ -829,7 +830,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
                pos += vec->iov_len;
        }
        nfs_pageio_complete(&desc);
-       NFS_I(dreq->inode)->write_io += desc.pg_bytes_written;
 
        /*
         * If no bytes were started, return the error, and let the