nfs: don't dirty kernel pages read by direct-io

Replicate the logic in the commit:
fd/direct-io: introduce should_dirty for kernel aio

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 38678d9a5cc4a64838e70ff3c915107b828bb65d..8beeaf06e3606f0c7fe3968227d949cea5e678b8 100644 (file)
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -97,8 +97,11 @@ struct nfs_direct_req {
        struct pnfs_ds_commit_info ds_cinfo;    /* Storage for cinfo */
        struct work_struct      work;
        int                     flags;
+       /* for write */
 #define NFS_ODIRECT_DO_COMMIT          (1)     /* an unstable reply was received */
 #define NFS_ODIRECT_RESCHED_WRITES     (2)     /* write verification failed */
+       /* for read */
+#define NFS_ODIRECT_SHOULD_DIRTY       (3)     /* dirty user-space page after read */
        struct nfs_writeverf    verf;           /* unstable write verifier */
 };
 
@@ -426,7 +429,8 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
                struct nfs_page *req = nfs_list_entry(hdr->pages.next);
                struct page *page = req->wb_page;
 
-               if (!PageCompound(page) && bytes < hdr->good_bytes)
+               if (!PageCompound(page) && bytes < hdr->good_bytes &&
+                   (dreq->flags == NFS_ODIRECT_SHOULD_DIRTY))
                        set_page_dirty(page);
                bytes += req->wb_bytes;
                nfs_list_remove_request(req);
@@ -608,6 +612,11 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
        if (!is_sync_kiocb(iocb))
                dreq->iocb = iocb;
 
+       if (iter_is_iovec(iter))
+               dreq->flags = NFS_ODIRECT_SHOULD_DIRTY;
+       else
+               dreq->flags = 0;
+
        NFS_I(inode)->read_io += count;
        result = nfs_direct_read_schedule_iovec(dreq, iter, pos);