From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932379AbWGLSSv (ORCPT ); Wed, 12 Jul 2006 14:18:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932385AbWGLSRs (ORCPT ); Wed, 12 Jul 2006 14:17:48 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:60901 "EHLO e31.co.us.ibm.com") by vger.kernel.org with ESMTP id S932380AbWGLSRa (ORCPT ); Wed, 12 Jul 2006 14:17:30 -0400 Subject: [RFC][PATCH 21/27] elevate write count for do_sys_utime() and touch_atime() To: viro@ftp.linux.org.uk Cc: serue@us.ibm.com, linux-kernel@vger.kernel.org, Dave Hansen From: Dave Hansen Date: Wed, 12 Jul 2006 11:17:24 -0700 References: <20060712181709.5C1A4353@localhost.localdomain> In-Reply-To: <20060712181709.5C1A4353@localhost.localdomain> Message-Id: <20060712181724.4FB246B0@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: Dave Hansen --- lxc-dave/fs/inode.c | 9 +++++++-- lxc-dave/fs/open.c | 16 +++++++++++----- 2 files changed, 18 insertions(+), 7 deletions(-) diff -puN fs/inode.c~C-elevate-writers-opens-part2-do_sys_utime fs/inode.c --- lxc/fs/inode.c~C-elevate-writers-opens-part2-do_sys_utime 2006-07-12 11:09:23.000000000 -0700 +++ lxc-dave/fs/inode.c 2006-07-12 11:09:38.000000000 -0700 @@ -1191,10 +1191,13 @@ void touch_atime(struct vfsmount *mnt, s if (IS_RDONLY(inode)) return; + if (mnt_want_write(mnt)) + return; + if ((inode->i_flags & S_NOATIME) || (inode->i_sb->s_flags & MS_NOATIME) || ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))) - return; + goto out; /* * We may have a NULL vfsmount when coming from NFSD @@ -1202,13 +1205,15 @@ void touch_atime(struct vfsmount *mnt, s if (mnt && ((mnt->mnt_flags & MNT_NOATIME) || ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))) - return; + goto out; now = current_fs_time(inode->i_sb); if (!timespec_equal(&inode->i_atime, &now)) { inode->i_atime = now; mark_inode_dirty_sync(inode); } +out: + mnt_drop_write(mnt); } EXPORT_SYMBOL(touch_atime); diff -puN fs/open.c~C-elevate-writers-opens-part2-do_sys_utime fs/open.c --- lxc/fs/open.c~C-elevate-writers-opens-part2-do_sys_utime 2006-07-12 11:09:37.000000000 -0700 +++ lxc-dave/fs/open.c 2006-07-12 11:09:38.000000000 -0700 @@ -384,16 +384,20 @@ asmlinkage long sys_utime(char __user * goto out; inode = nd.dentry->d_inode; + error = mnt_want_write(nd.mnt); + if (error) + goto dput_and_out; + error = -EROFS; if (IS_RDONLY(inode)) - goto dput_and_out; + goto mnt_drop_write_and_out; /* Don't worry, the checks are done in inode_change_ok() */ newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; if (times) { error = -EPERM; if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) - goto dput_and_out; + goto mnt_drop_write_and_out; error = get_user(newattrs.ia_atime.tv_sec, ×->actime); newattrs.ia_atime.tv_nsec = 0; @@ -401,21 +405,23 @@ asmlinkage long sys_utime(char __user * error = get_user(newattrs.ia_mtime.tv_sec, ×->modtime); newattrs.ia_mtime.tv_nsec = 0; if (error) - goto dput_and_out; + goto mnt_drop_write_and_out; newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; } else { error = -EACCES; if (IS_IMMUTABLE(inode)) - goto dput_and_out; + goto mnt_drop_write_and_out; if (current->fsuid != inode->i_uid && (error = vfs_permission(&nd, MAY_WRITE)) != 0) - goto dput_and_out; + goto mnt_drop_write_and_out; } mutex_lock(&inode->i_mutex); error = notify_change(nd.dentry, &newattrs); mutex_unlock(&inode->i_mutex); +mnt_drop_write_and_out: + mnt_drop_write(nd.mnt); dput_and_out: path_release(&nd); out: _