Forwarding to the current cifs development mailing list
---------- Forwarded message ---------- From: <[email protected]> Date: Wed, Feb 6, 2013 at 12:26 AM Subject: [PATCH] cifs: bugfix for unreclaimed writeback pages in cifs_writev_requeue() To: Steve French <[email protected]>, [email protected] This patch applies to the kernel version of linux-3.8-rc6. 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=<cifs file>) 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 <[email protected]> Signed-off-by: Jiang Yong <[email protected]> Tested-by: Zhang Xianwei <[email protected]> Reviewed-by: Wang Liang <[email protected]> Reviewed-by: Cai Qu <[email protected]> Reviewed-by: Jiang Biao <[email protected]> diff -uprN linux-3.8-rc6/fs/cifs/cifssmb.c linux-3.8-rc6_new/fs/cifs/cifssmb.c --- linux-3.8-rc6/fs/cifs/cifssmb.c 2013-02-01 09:08:14.000000000 +0800 +++ linux-3.8-rc6_new/fs/cifs/cifssmb.c 2013-02-04 15:44:09.869254397 +0800 @@ -1909,8 +1909,11 @@ cifs_writev_requeue(struct cifs_writedat } 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]); } -------------------------------------------------------- ZTE Information Security Notice: The information contained in this mail (and any attachment transmitted herewith) is privileged and confidential and is intended for the exclusive use of the addressee(s). If you are not an intended recipient, any disclosure, reproduction, distribution or other dissemination or use of the information contained is strictly prohibited. If you have received this mail in error, please delete it and notify us immediately. -- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
