From patchwork Thu Jul 18 19:35:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Adamson X-Patchwork-Id: 2829781 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id ACCD79FA38 for ; Thu, 18 Jul 2013 19:35:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AE2FB20120 for ; Thu, 18 Jul 2013 19:35:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7497E2011E for ; Thu, 18 Jul 2013 19:35:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759338Ab3GRTfm (ORCPT ); Thu, 18 Jul 2013 15:35:42 -0400 Received: from mx12.netapp.com ([216.240.18.77]:50474 "EHLO mx12.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759348Ab3GRTfm (ORCPT ); Thu, 18 Jul 2013 15:35:42 -0400 X-IronPort-AV: E=Sophos;i="4.89,696,1367996400"; d="scan'208";a="74351747" Received: from vmwexceht03-prd.hq.netapp.com ([10.106.76.241]) by mx12-out.netapp.com with ESMTP; 18 Jul 2013 12:35:42 -0700 Received: from smtp1.corp.netapp.com (10.57.156.124) by VMWEXCEHT03-PRD.hq.netapp.com (10.106.76.241) with Microsoft SMTP Server id 14.3.123.3; Thu, 18 Jul 2013 12:35:41 -0700 Received: from fc19.androsad.fake (vpn2ntap-178991.vpn.netapp.com [10.55.73.80]) by smtp1.corp.netapp.com (8.13.1/8.13.1/NTAP-1.6) with ESMTP id r6IJZbRK021126; Thu, 18 Jul 2013 12:35:40 -0700 (PDT) From: To: CC: , Andy Adamson Subject: [PATCH Version 4 4/5] NFS avoid expired credential keys for buffered writes Date: Thu, 18 Jul 2013 15:35:29 -0400 Message-ID: <1374176130-11657-5-git-send-email-andros@netapp.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1374176130-11657-1-git-send-email-andros@netapp.com> References: <1374176130-11657-1-git-send-email-andros@netapp.com> MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-7.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Andy Adamson We must avoid buffering a WRITE that is using a credential key (e.g. a GSS context key) that is about to expire. We currently will paint ourselves into a corner by returning success to the applciation for such a buffered WRITE, only to discover that we do not have permission when we attempt to flush the WRITE (and potentially associated COMMIT) to disk. Use the RPC layer credential key timeout and expire routines which use a a watermark, gss_key_expire_timeo. We test the key in nfs_file_write. If a WRITE is using a credential with a key that will expire within watermark seconds, flush the inode in nfs_write_end and send only NFS_FILE_SYNC WRITEs by adding nfs_ctx_key_to_expire to nfs_need_sync_write. Note that this results in single page NFS_FILE_SYNC WRITEs. Signed-off-by: Andy Adamson --- fs/nfs/file.c | 19 ++++++++++++++++++- fs/nfs/internal.h | 2 ++ fs/nfs/write.c | 27 +++++++++++++++++++++++++++ 3 files changed, 47 insertions(+), 1 deletion(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 94e94bd..dfff8df 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -406,6 +406,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping, struct page *page, void *fsdata) { unsigned offset = pos & (PAGE_CACHE_SIZE - 1); + struct nfs_open_context *ctx = nfs_file_open_context(file); int status; dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n", @@ -441,6 +442,17 @@ static int nfs_write_end(struct file *file, struct address_space *mapping, if (status < 0) return status; NFS_I(mapping->host)->write_io += copied; + + if (nfs_ctx_key_to_expire(ctx)) { + pr_warn_once("NFS: Credential Key to expire. Flush %s/%s(%ld)\n", + file->f_path.dentry->d_parent->d_name.name, + file->f_path.dentry->d_name.name, + mapping->host->i_ino); + status = nfs_wb_all(mapping->host); + if (status < 0) + return status; + } + return copied; } @@ -637,7 +649,8 @@ static int nfs_need_sync_write(struct file *filp, struct inode *inode) if (IS_SYNC(inode) || (filp->f_flags & O_DSYNC)) return 1; ctx = nfs_file_open_context(filp); - if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags)) + if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags) || + nfs_ctx_key_to_expire(ctx)) return 1; return 0; } @@ -651,6 +664,10 @@ ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov, ssize_t result; size_t count = iov_length(iov, nr_segs); + result = nfs_key_timeout_notify(iocb->ki_filp, inode); + if (result) + return result; + if (iocb->ki_filp->f_flags & O_DIRECT) return nfs_file_direct_write(iocb, iov, nr_segs, pos, true); diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 3c8373f..e86dc20 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -430,6 +430,8 @@ void nfs_request_remove_commit_list(struct nfs_page *req, void nfs_init_cinfo(struct nfs_commit_info *cinfo, struct inode *inode, struct nfs_direct_req *dreq); +int nfs_key_timeout_notify(struct file *filp, struct inode *inode); +bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx); #ifdef CONFIG_MIGRATION extern int nfs_migrate_page(struct address_space *, diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 724c845..144085c 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -874,6 +874,33 @@ int nfs_flush_incompatible(struct file *file, struct page *page) } /* + * Avoid buffered writes when a open context credential's key would + * expire soon. + * + * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL. + * + * Return 0 and set a credential flag which triggers the inode to flush + * and performs NFS_FILE_SYNC writes if the key will expired within + * RPC_KEY_EXPIRE_TIMEO. + */ +int +nfs_key_timeout_notify(struct file *filp, struct inode *inode) +{ + struct nfs_open_context *ctx = nfs_file_open_context(filp); + struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth; + + return rpcauth_key_timeout_notify(auth, ctx->cred); +} + +/* + * Test if the open context credential key is marked to expire soon. + */ +bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx) +{ + return rpcauth_cred_key_to_expire(ctx->cred); +} + +/* * If the page cache is marked as unsafe or invalid, then we can't rely on * the PageUptodate() flag. In this case, we will need to turn off * write optimisations that depend on the page contents being correct.