From c51bb0ea40ca038da26b1fa7d450f4078124af03 Mon Sep 17 00:00:00 2001 From: Ouyang Maochun Date: Mon, 18 Feb 2013 09:54:52 -0600 Subject: [PATCH] cifs: bugfix for unreclaimed writeback pages in cifs_writev_requeue() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Pages get the PG_writeback flag set before cifs sends its request to SMB server in cifs_writepages(), if the SMB service goes down, cifs may try to recommit the writing requests in cifs_writev_requeue(). However, it does not clean its PG_writeback flag and relaimed the pages even if it fails again in cifs_writev_requeue(), which may lead to the hanging of the processes accessing the cifs directory. This patch just cleans the PG_writeback flags and reclaims the pages under that circumstances. Steps to reproduce the bug(trying serveral times may trigger the issue): 1.Write from cifs client continuously.(e.g dd if=/dev/zero of=) 2.Stop SMB service from server.(e.g service smb stop) 3.Wait for two minutes， and then start SMB service from server.(e.g service smb start) 4.The processes which are accessing cifs directory may hang up. Signed-off-by: Ouyang Maochun Signed-off-by: Jiang Yong Tested-by: Zhang Xianwei Reviewed-by: Wang Liang Reviewed-by: Cai Qu Reviewed-by: Jiang Biao Reviewed-by: Jeff Layton Reviewed-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 00e12f2d626..7353bc5d73d 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -1909,8 +1909,11 @@ cifs_writev_requeue(struct cifs_writedata *wdata) } while (rc == -EAGAIN); for (i = 0; i < wdata->nr_pages; i++) { - if (rc != 0) + if (rc != 0) { SetPageError(wdata->pages[i]); + end_page_writeback(wdata->pages[i]); + page_cache_release(wdata->pages[i]); + } unlock_page(wdata->pages[i]); } -- 2.41.0