(1) If a writeback has been partially flushed, then if we try and kill the pages it contains, some of them may no longer be undergoing writeback and end_page_writeback() will assert.

Fix this by checking to see whether the page in question is actually undergoing writeback before ending that writeback.

(2) The loop that scans for pages to kill doesn't increase the first page index, and so the loop may not terminate, but it will try to process the same pages over and over again.

Fix this by increasing the first page index to one after the last page we processed.

Signed-off-by David Howells <[email protected]>

Signed-off-by Sasha Levin <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 fs/afs/write.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

fs/afs/write.c +7 -3

@@ -299,10 +299,14 @@ static void afs_kill_pages(struct afs_vn
 		ASSERTCMP(pv.nr, ==, count);
 
 		for (loop = 0; loop < count; loop++) {
-			ClearPageUptodate(pv.pages[loop]);
+			struct page *page = pv.pages[loop];
+			ClearPageUptodate(page);
 			if (error)
-				SetPageError(pv.pages[loop]);
-			end_page_writeback(pv.pages[loop]);
+				SetPageError(page);
+			if (PageWriteback(page))
+				end_page_writeback(page);
+			if (page->index >= first)
+				first = page->index + 1;
 		}
 
 		__pagevec_release(&pv);

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/afs-flush-outstanding-writes-when-an-fd-is-closed.patch queue-4.4/afs-fix-the-maths-in-afs_fs_store_data.patch queue-4.4/afs-populate-group-id-from-vnode-status.patch queue-4.4/afs-prevent-callback-expiry-timer-overflow.patch queue-4.4/keys-add-missing-permission-check-for-request_key-destination.patch queue-4.4/afs-adjust-mode-bits-processing.patch queue-4.4/afs-fix-page-leak-in-afs_write_begin.patch queue-4.4/afs-fix-missing-put_page.patch queue-4.4/afs-migrate-vlocation-fields-to-64-bit.patch queue-4.4/afs-populate-and-use-client-modification-time.patch queue-4.4/afs-fix-afs_kill_pages.patch