NFS: Remove private spinlock in struct nfs_pgio_header

Now that each struct nfs_pgio_header corresponds to one RPC call, we
only have one writer to the struct nfs_pgio_header.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index bb5476a..f97c455 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -63,14 +63,14 @@ EXPORT_SYMBOL_GPL(nfs_pgheader_init);
 
 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
 {
-	spin_lock(&hdr->lock);
-	if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags)
-	    || pos < hdr->io_start + hdr->good_bytes) {
+	unsigned int new = pos - hdr->io_start;
+
+	if (hdr->good_bytes > new) {
+		hdr->good_bytes = new;
 		clear_bit(NFS_IOHDR_EOF, &hdr->flags);
-		hdr->good_bytes = pos - hdr->io_start;
-		hdr->error = error;
+		if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags))
+			hdr->error = error;
 	}
-	spin_unlock(&hdr->lock);
 }
 
 static inline struct nfs_page *
@@ -494,7 +494,6 @@ struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
 
 	if (hdr) {
 		INIT_LIST_HEAD(&hdr->pages);
-		spin_lock_init(&hdr->lock);
 		hdr->rw_ops = ops;
 	}
 	return hdr;