From patchwork Mon Mar 28 20:09:09 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 669892 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p2SK9Ksk011345 for ; Mon, 28 Mar 2011 20:09:20 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754987Ab1C1UJT (ORCPT ); Mon, 28 Mar 2011 16:09:19 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:37625 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754759Ab1C1UJT (ORCPT ); Mon, 28 Mar 2011 16:09:19 -0400 Received: by gxk21 with SMTP id 21so1309979gxk.19 for ; Mon, 28 Mar 2011 13:09:18 -0700 (PDT) Received: by 10.101.178.21 with SMTP id f21mr241779anp.32.1301342958549; Mon, 28 Mar 2011 13:09:18 -0700 (PDT) Received: from salusa.poochiereds.net (cpe-075-177-180-210.nc.res.rr.com [75.177.180.210]) by mx.google.com with ESMTPS id b28sm1589223anb.48.2011.03.28.13.09.16 (version=SSLv3 cipher=OTHER); Mon, 28 Mar 2011 13:09:17 -0700 (PDT) From: Jeff Layton To: smfrench@gmail.com Cc: piastryyy@gmail.com, linux-cifs@vger.kernel.org Subject: [PATCH] cifs: don't allow mmap'ed pages to be dirtied while under writeback (try #2) Date: Mon, 28 Mar 2011 16:09:09 -0400 Message-Id: <1301342949-25330-1-git-send-email-jlayton@redhat.com> X-Mailer: git-send-email 1.7.4 In-Reply-To: References: Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Mon, 28 Mar 2011 20:09:20 +0000 (UTC) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index de49fbb..1af2470 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -81,10 +81,6 @@ module_param(echo_retries, ushort, 0644); MODULE_PARM_DESC(echo_retries, "Number of echo attempts before giving up and " "reconnecting server. Default: 5. 0 means " "never reconnect."); -bool sign_zero_copy; /* globals init to false automatically */ -module_param(sign_zero_copy, bool, 0644); -MODULE_PARM_DESC(sign_zero_copy, "Don't copy pages on write with signing " - "enabled. Default: N"); extern mempool_t *cifs_sm_req_poolp; extern mempool_t *cifs_req_poolp; extern mempool_t *cifs_mid_poolp; diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 2c52c14..ccbac61 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -907,7 +907,6 @@ GLOBAL_EXTERN unsigned int CIFSMaxBufSize; /* max size not including hdr */ GLOBAL_EXTERN unsigned int cifs_min_rcv; /* min size of big ntwrk buf pool */ GLOBAL_EXTERN unsigned int cifs_min_small; /* min size of small buf pool */ GLOBAL_EXTERN unsigned int cifs_max_pending; /* MAX requests at once to server*/ -GLOBAL_EXTERN bool sign_zero_copy; /* don't copy written pages with signing */ /* reconnect after this many failed echo attempts */ GLOBAL_EXTERN unsigned short echo_retries; diff --git a/fs/cifs/file.c b/fs/cifs/file.c index b9731c9..da53246 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -881,6 +881,9 @@ static ssize_t cifs_write(struct cifsFileInfo *open_file, total_written += bytes_written) { rc = -EAGAIN; while (rc == -EAGAIN) { + struct kvec iov[2]; + unsigned int len; + if (open_file->invalidHandle) { /* we could deadlock if we called filemap_fdatawait from here so tell @@ -890,31 +893,14 @@ static ssize_t cifs_write(struct cifsFileInfo *open_file, if (rc != 0) break; } - if (sign_zero_copy || (pTcon->ses->server && - ((pTcon->ses->server->sec_mode & - (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) - == 0))) { - struct kvec iov[2]; - unsigned int len; - - len = min((size_t)cifs_sb->wsize, - write_size - total_written); - /* iov[0] is reserved for smb header */ - iov[1].iov_base = (char *)write_data + - total_written; - iov[1].iov_len = len; - rc = CIFSSMBWrite2(xid, pTcon, - open_file->netfid, len, - *poffset, &bytes_written, - iov, 1, 0); - } else - rc = CIFSSMBWrite(xid, pTcon, - open_file->netfid, - min_t(const int, cifs_sb->wsize, - write_size - total_written), - *poffset, &bytes_written, - write_data + total_written, - NULL, 0); + + len = min((size_t)cifs_sb->wsize, + write_size - total_written); + /* iov[0] is reserved for smb header */ + iov[1].iov_base = (char *)write_data + total_written; + iov[1].iov_len = len; + rc = CIFSSMBWrite2(xid, pTcon, open_file->netfid, len, + *poffset, &bytes_written, iov, 1, 0); } if (rc || (bytes_written == 0)) { if (total_written) @@ -1151,12 +1137,6 @@ static int cifs_writepages(struct address_space *mapping, } tcon = tlink_tcon(open_file->tlink); - if (!sign_zero_copy && tcon->ses->server->sec_mode & - (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) { - cifsFileInfo_put(open_file); - kfree(iov); - return generic_writepages(mapping, wbc); - } cifsFileInfo_put(open_file); xid = GetXid(); @@ -1909,6 +1889,24 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size, return total_read; } +/* + * If the page is mmap'ed into a process' page tables, then we need to make + * sure that it doesn't change while being written back. + */ +static int +cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct page *page = vmf->page; + + lock_page(page); + return VM_FAULT_LOCKED; +} + +static struct vm_operations_struct cifs_file_vm_ops = { + .fault = filemap_fault, + .page_mkwrite = cifs_page_mkwrite, +}; + int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma) { int rc, xid; @@ -1920,6 +1918,8 @@ int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma) cifs_invalidate_mapping(inode); rc = generic_file_mmap(file, vma); + if (rc == 0) + vma->vm_ops = &cifs_file_vm_ops; FreeXid(xid); return rc; } @@ -1936,6 +1936,8 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma) return rc; } rc = generic_file_mmap(file, vma); + if (rc == 0) + vma->vm_ops = &cifs_file_vm_ops; FreeXid(xid); return rc; }