nfs: handle multiple reqs in nfs_wb_page_cancel

Use nfs_lock_and_join_requests to merge all subrequests into the head request -
this cancels and dereferences all subrequests.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 9f4424c..bdc4db2 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1799,27 +1799,28 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
        struct nfs_page *req;
        int ret = 0;
 
-       for (;;) {
-               wait_on_page_writeback(page);
-               req = nfs_page_find_head_request(page);
-               if (req == NULL)
-                       break;
-               if (nfs_lock_request(req)) {
-                       nfs_clear_request_commit(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_and_release_request(req);
-                       break;
-               }
-               ret = nfs_wait_on_request(req);
-               nfs_release_request(req);
-               if (ret < 0)
-                       break;
+       wait_on_page_writeback(page);
+
+       /* blocking call to cancel all requests and join to a single (head)
+        * request */
+       req = nfs_lock_and_join_requests(page, false);
+
+       if (IS_ERR(req)) {
+               ret = PTR_ERR(req);
+       } else if (req) {
+               /* all requests from this page have been cancelled by
+                * nfs_lock_and_join_requests, so just remove the head
+                * request from the inode / page_private pointer and
+                * release it */
+               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_and_release_request(req);
        }
+
        return ret;
 }