1 files changed, 44 insertions, 0 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index ef97e0c0f5b1..0d7a77cc394b 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1396,6 +1396,50 @@ out:
         return ret;
 }
 
+int nfs_wb_page_cancel(struct inode *inode, struct page *page)
+{
+        struct nfs_page *req;
+        loff_t range_start = page_offset(page);
+        loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
+        struct writeback_control wbc = {
+                .bdi = page->mapping->backing_dev_info,
+                .sync_mode = WB_SYNC_ALL,
+                .nr_to_write = LONG_MAX,
+                .range_start = range_start,
+                .range_end = range_end,
+        };
+        int ret = 0;
+
+        BUG_ON(!PageLocked(page));
+        for (;;) {
+                req = nfs_page_find_request(page);
+                if (req == NULL)
+                        goto out;
+                if (test_bit(PG_NEED_COMMIT, &req->wb_flags)) {
+                        nfs_release_request(req);
+                        break;
+                }
+                if (nfs_lock_request_dontget(req)) {
+                        nfs_inode_remove_request(req);
+                        /*
+                         * In case nfs_inode_remove_request has marked the
+                         * page as being dirty
+                         */
+                        cancel_dirty_page(page, PAGE_CACHE_SIZE);
+                        nfs_unlock_request(req);
+                        break;
+                }
+                ret = nfs_wait_on_request(req);
+                if (ret < 0)
+                        goto out;
+        }
+        if (!PagePrivate(page))
+                return 0;
+        ret = nfs_sync_mapping_wait(page->mapping, &wbc, FLUSH_INVALIDATE);
+out:
+        return ret;
+}
+
 int nfs_wb_page_priority(struct inode *inode, struct page *page, int how)
 {
         loff_t range_start = page_offset(page);