[Cluster-devel] [PATCH 01/15] FOLD: iomap: make the discard_page method optional

[Christoph Hellwig]

For file system that do not support delayed allocations there is
nothing to discard here, so don't require them to implement the
method.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 fs/iomap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/iomap.c b/fs/iomap.c
index 72ba3962acf3..ebfff663b2a9 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -2545,7 +2545,8 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
 	 */
 	if (unlikely(error)) {
 		if (!count) {
-			wpc->ops->discard_page(page);
+			if (wpc->ops->discard_page)
+				wpc->ops->discard_page(page);
 			ClearPageUptodate(page);
 			unlock_page(page);
 			goto done;
-- 
2.20.1