From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757098AbZEUAao (ORCPT ); Wed, 20 May 2009 20:30:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756634AbZEUA2f (ORCPT ); Wed, 20 May 2009 20:28:35 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:46327 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754216AbZEUA2R (ORCPT ); Wed, 20 May 2009 20:28:17 -0400 From: "Eric W. Biederman" To: Andrew Morton , Greg Kroah-Hartman Cc: , Tejun Heo , Cornelia Huck , , "Eric W. Biederman" , "Eric W. Biederman" Subject: [PATCH 08/20] sysfs: Optimize just changing the sysfs file mode. Date: Wed, 20 May 2009 17:28:02 -0700 Message-Id: <1242865694-2100-8-git-send-email-ebiederm@xmission.com> X-Mailer: git-send-email 1.6.1.2.350.g88cc In-Reply-To: <1242865694-2100-7-git-send-email-ebiederm@xmission.com> References: <1242865694-2100-1-git-send-email-ebiederm@xmission.com> <1242865694-2100-2-git-send-email-ebiederm@xmission.com> <1242865694-2100-3-git-send-email-ebiederm@xmission.com> <1242865694-2100-4-git-send-email-ebiederm@xmission.com> <1242865694-2100-5-git-send-email-ebiederm@xmission.com> <1242865694-2100-6-git-send-email-ebiederm@xmission.com> <1242865694-2100-7-git-send-email-ebiederm@xmission.com> X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Rcpt-To: akpm@linux-foundation.org, gregkh@suse.de, linux-kernel@vger.kernel.org, tj@kernel.org, cornelia.huck@de.ibm.com, linux-fsdevel@vger.kernel.org, ebiederm@xmission.com, ebiederm@aristanetworks.com X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: No (on in02.mta.xmission.com); Unknown failure Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric W. Biederman Don't allocate a struct iattr for the sysfs dentry if just the mode changes because we have a field for that on the sysfs_dirent, and we can trigger that case with sysfs_chmod_file. Signed-off-by: Eric W. Biederman --- fs/sysfs/inode.c | 22 ++++++++++++++-------- 1 files changed, 14 insertions(+), 8 deletions(-) diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 555f0ff..70ff2a2 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -60,12 +60,16 @@ int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) return error; iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */ + if (iattr->ia_valid & ATTR_MODE) { + if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) + iattr->ia_mode &= ~S_ISGID; + } error = inode_setattr(inode, iattr); if (error) return error; - if (!sd_iattr) { + if (!sd_iattr && (ia_valid & ~ATTR_MODE)) { /* setting attributes for the first time, allocate now */ sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL); if (!sd_iattr) @@ -78,6 +82,13 @@ int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) sd->s_iattr = sd_iattr; } + if (ia_valid & ATTR_MODE) + sd->s_mode = iattr->ia_mode; + + /* If we don't need the extra attributes leave */ + if (!sd_iattr) + return 0; + /* attributes were changed atleast once in past */ if (ia_valid & ATTR_UID) @@ -93,13 +104,8 @@ int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) if (ia_valid & ATTR_CTIME) sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime, inode->i_sb->s_time_gran); - if (ia_valid & ATTR_MODE) { - umode_t mode = iattr->ia_mode; - - if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) - mode &= ~S_ISGID; - sd_iattr->ia_mode = sd->s_mode = mode; - } + if (ia_valid & ATTR_MODE) + sd_iattr->ia_mode = iattr->ia_mode; return error; } -- 1.6.1.2.350.g88cc