cifs: add wrapper for cifs_async_readv to retry opening file

We'll need this same bit of code for the uncached case.
Signed-off-by: Jeff Layton <jlayton@redhat.com>

fs/cifs/file.c

@@ -2366,6 +2366,23 @@ cifs_readdata_release(struct kref *refcount)
 	kfree(rdata);
 }
 
+static int
+cifs_retry_async_readv(struct cifs_readdata *rdata)
+{
+	int rc;
+
+	do {
+		if (rdata->cfile->invalidHandle) {
+			rc = cifs_reopen_file(rdata->cfile, true);
+			if (rc != 0)
+				continue;
+		}
+		rc = cifs_async_readv(rdata);
+	} while (rc == -EAGAIN);
+
+	return rc;
+}
+
 static ssize_t
 cifs_iovec_read(struct file *file, const struct iovec *iov,
 		 unsigned long nr_segs, loff_t *poffset)
@@ -2852,15 +2869,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
 		rdata->marshal_iov = cifs_readpages_marshal_iov;
 		list_splice_init(&tmplist, &rdata->pages);
 
-		do {
-			if (open_file->invalidHandle) {
-				rc = cifs_reopen_file(open_file, true);
-				if (rc != 0)
-					continue;
-			}
-			rc = cifs_async_readv(rdata);
-		} while (rc == -EAGAIN);
-
+		rc = cifs_retry_async_readv(rdata);
 		if (rc != 0) {
 			list_for_each_entry_safe(page, tpage, &rdata->pages,
 						 lru) {