Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754410AbZKDDQc (ORCPT ); Tue, 3 Nov 2009 22:16:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754349AbZKDDQa (ORCPT ); Tue, 3 Nov 2009 22:16:30 -0500 Received: from e5.ny.us.ibm.com ([32.97.182.145]:56608 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753946AbZKDDQ3 (ORCPT ); Tue, 3 Nov 2009 22:16:29 -0500 Date: Tue, 3 Nov 2009 21:16:32 -0600 From: "Serge E. Hallyn" To: "Eric W. Biederman" Cc: Greg Kroah-Hartman , Kay Sievers , Greg KH , linux-kernel@vger.kernel.org, Tejun Heo , Cornelia Huck , linux-fsdevel@vger.kernel.org, Eric Dumazet , Benjamin LaHaise , "Eric W. Biederman" Subject: Re: [PATCH 06/13] sysfs: Fix locking and factor out sysfs_sd_setattr Message-ID: <20091104031632.GC27639@us.ibm.com> References: <1257249429-12384-6-git-send-email-ebiederm@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1257249429-12384-6-git-send-email-ebiederm@xmission.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4114 Lines: 130 Quoting Eric W. Biederman (ebiederm@xmission.com): > From: Eric W. Biederman > > Cleanly separate the work that is specific to setting the > attributes of a sysfs_dirent from what is needed to update > the attributes of a vfs inode. > > Additionally grab the sysfs_mutex to keep any nasties from > surprising us when updating the sysfs_dirent. > > Acked-by: Tejun Heo > Signed-off-by: Eric W. Biederman > --- > fs/sysfs/inode.c | 52 ++++++++++++++++++++++++++++++++-------------------- > fs/sysfs/sysfs.h | 1 + > 2 files changed, 33 insertions(+), 20 deletions(-) > > diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c > index fed7a74..fccfb55 100644 > --- a/fs/sysfs/inode.c > +++ b/fs/sysfs/inode.c > @@ -64,30 +64,15 @@ struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd) > > return attrs; > } > -int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) > + > +int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr * iattr) > { > - struct inode * inode = dentry->d_inode; > - struct sysfs_dirent * sd = dentry->d_fsdata; > struct sysfs_inode_attrs *sd_attrs; > struct iattr *iattrs; > unsigned int ia_valid = iattr->ia_valid; > - int error; > - > - if (!sd) > - return -EINVAL; > > sd_attrs = sd->s_iattr; > > - error = inode_change_ok(inode, iattr); > - if (error) > - return error; > - > - iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */ > - > - error = inode_setattr(inode, iattr); > - if (error) > - return error; > - > if (!sd_attrs) { > /* setting attributes for the first time, allocate now */ > sd_attrs = sysfs_init_inode_attrs(sd); > @@ -110,12 +95,39 @@ int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) > iattrs->ia_ctime = iattr->ia_ctime; > if (ia_valid & ATTR_MODE) { > umode_t mode = iattr->ia_mode; > - > - if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) > - mode &= ~S_ISGID; > iattrs->ia_mode = sd->s_mode = mode; > } > } > + return 0; > +} > + > +int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) > +{ > + struct inode * inode = dentry->d_inode; > + struct sysfs_dirent * sd = dentry->d_fsdata; > + int error; > + > + if (!sd) > + return -EINVAL; > + > + error = inode_change_ok(inode, iattr); > + if (error) > + 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; > + } Was it a bug that before this patch this wasn't cleared before the actual inode_setattr()? Since the S_ISGID will be set for the *new* gid, that is, iattr->ia_gid, shouldn't the user be required to be in_group_p(iattr->i_gid)? Note you haven't done the inode_setattr() yet. > + > + error = inode_setattr(inode, iattr); > + if (error) > + return error; > + > + mutex_lock(&sysfs_mutex); > + error = sysfs_sd_setattr(sd, iattr); > + mutex_unlock(&sysfs_mutex); > + > return error; > } > > diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h > index af4c4e7..a96d967 100644 > --- a/fs/sysfs/sysfs.h > +++ b/fs/sysfs/sysfs.h > @@ -155,6 +155,7 @@ static inline void __sysfs_put(struct sysfs_dirent *sd) > */ > struct inode *sysfs_get_inode(struct sysfs_dirent *sd); > void sysfs_delete_inode(struct inode *inode); > +int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr); > int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); > int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, > size_t size, int flags); > -- > 1.6.5.2.143.g8cc62 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/