From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933854Ab1DNSKn (ORCPT ); Thu, 14 Apr 2011 14:10:43 -0400 Received: from mail.windriver.com ([147.11.1.11]:42102 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933700Ab1DNR6b (ORCPT ); Thu, 14 Apr 2011 13:58:31 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Neil Brown , "J. Bruce Fields" , Paul Gortmaker Subject: [34-longterm 163/209] nfsd: Fix possible BUG_ON firing in set_change_info Date: Thu, 14 Apr 2011 13:55:21 -0400 Message-Id: <1302803767-9715-50-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1302803767-9715-1-git-send-email-paul.gortmaker@windriver.com> References: <1302803039-9400-1-git-send-email-paul.gortmaker@windriver.com> <1302803767-9715-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Neil Brown ===================================================================== | This is a commit scheduled for the next v2.6.34 longterm release. | | If you see a problem with using this for longterm, please comment.| ===================================================================== commit c1ac3ffcd0bc7e9617f62be8c7043d53ab84deac upstream. If vfs_getattr in fill_post_wcc returns an error, we don't set fh_post_change. For NFSv4, this can result in set_change_info triggering a BUG_ON. i.e. fh_post_saved being zero isn't really a bug. So: - instead of BUGging when fh_post_saved is zero, just clear ->atomic. - if vfs_getattr fails in fill_post_wcc, take a copy of i_ctime anyway. This will be used i seg_change_info, but not overly trusted. - While we are there, remove the pointless 'if' statements in set_change_info. There is no harm setting all the values. Signed-off-by: NeilBrown Signed-off-by: J. Bruce Fields Signed-off-by: Paul Gortmaker --- fs/nfsd/nfs3xdr.c | 6 ++++-- fs/nfsd/xdr4.h | 21 ++++++++++----------- 2 files changed, 14 insertions(+), 13 deletions(-) diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 2a533a0..7e84a85 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -260,9 +260,11 @@ void fill_post_wcc(struct svc_fh *fhp) err = vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &fhp->fh_post_attr); fhp->fh_post_change = fhp->fh_dentry->d_inode->i_version; - if (err) + if (err) { fhp->fh_post_saved = 0; - else + /* Grab the ctime anyway - set_change_info might use it */ + fhp->fh_post_attr.ctime = fhp->fh_dentry->d_inode->i_ctime; + } else fhp->fh_post_saved = 1; } diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h index efa3377..c1aed78 100644 --- a/fs/nfsd/xdr4.h +++ b/fs/nfsd/xdr4.h @@ -479,18 +479,17 @@ static inline bool nfsd4_not_cached(struct nfsd4_compoundres *resp) static inline void set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp) { - BUG_ON(!fhp->fh_pre_saved || !fhp->fh_post_saved); - cinfo->atomic = 1; + BUG_ON(!fhp->fh_pre_saved); + cinfo->atomic = fhp->fh_post_saved; cinfo->change_supported = IS_I_VERSION(fhp->fh_dentry->d_inode); - if (cinfo->change_supported) { - cinfo->before_change = fhp->fh_pre_change; - cinfo->after_change = fhp->fh_post_change; - } else { - cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec; - cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec; - cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec; - cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec; - } + + cinfo->before_change = fhp->fh_pre_change; + cinfo->after_change = fhp->fh_post_change; + cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec; + cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec; + cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec; + cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec; + } int nfs4svc_encode_voidres(struct svc_rqst *, __be32 *, void *); -- 1.7.4.4