From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: [RFC][PATCH 06/27] elevate write count during entire ncp_ioctl() Date: Wed, 07 Jun 2006 17:10:18 -0700 Message-ID: <20060608001018.20E7FBE1@localhost.localdomain> References: <20060608001013.0D041507@localhost.localdomain> Cc: herbert@13thfloor.at, viro@ftp.linux.org.uk, hch@infradead.org, trond.myklebust@fys.uio.no, Dave Hansen Return-path: Received: from e36.co.us.ibm.com ([32.97.110.154]:64221 "EHLO e36.co.us.ibm.com") by vger.kernel.org with ESMTP id S932481AbWFHAK2 (ORCPT ); Wed, 7 Jun 2006 20:10:28 -0400 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e36.co.us.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id k580AOJx026529 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 7 Jun 2006 20:10:24 -0400 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by westrelay02.boulder.ibm.com (8.13.6/NCO/VER7.0) with ESMTP id k580AI2r188618 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 7 Jun 2006 18:10:19 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id k580AL61008256 for ; Wed, 7 Jun 2006 18:10:22 -0600 To: linux-fsdevel@vger.kernel.org In-Reply-To: <20060608001013.0D041507@localhost.localdomain> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Some ioctls need write access, but others don't. Make a helper function to decode when write access is needed, and take it. Signed-off-by: Dave Hansen --- fs/nfsd/vfs.c | 0 lxc-dave/fs/ncpfs/ioctl.c | 54 +++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 53 insertions(+), 1 deletion(-) diff -puN fs/namei.c~elevate-writers-file_permission-callers fs/namei.c diff -puN fs/open.c~elevate-writers-file_permission-callers fs/open.c diff -puN fs/exec.c~elevate-writers-file_permission-callers fs/exec.c diff -puN fs/ncpfs/ioctl.c~elevate-writers-file_permission-callers fs/ncpfs/ioctl.c --- lxc/fs/ncpfs/ioctl.c~elevate-writers-file_permission-callers 2006-06-07 16:53:15.000000000 -0700 +++ lxc-dave/fs/ncpfs/ioctl.c 2006-06-07 16:53:15.000000000 -0700 @@ -183,7 +183,7 @@ ncp_get_charsets(struct ncp_server* serv } #endif /* CONFIG_NCPFS_NLS */ -int ncp_ioctl(struct inode *inode, struct file *filp, +static int __ncp_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { struct ncp_server *server = NCP_SERVER(inode); @@ -654,3 +654,55 @@ outrel: /* #endif */ return -EINVAL; } + +static int ncp_ioctl_need_write(unsigned int cmd) +{ + switch (cmd) { + case NCP_IOC_GET_FS_INFO: + case NCP_IOC_GET_FS_INFO_V2: + case NCP_IOC_NCPREQUEST: + case NCP_IOC_SETDENTRYTTL: + case NCP_IOC_SIGN_INIT: + case NCP_IOC_LOCKUNLOCK: + case NCP_IOC_SET_SIGN_WANTED: + return 0; + case NCP_IOC_GETOBJECTNAME: + case NCP_IOC_SETOBJECTNAME: + case NCP_IOC_GETPRIVATEDATA: + case NCP_IOC_SETPRIVATEDATA: + case NCP_IOC_SETCHARSETS: + case NCP_IOC_GETCHARSETS: + case NCP_IOC_CONN_LOGGED_IN: + case NCP_IOC_GETDENTRYTTL: + case NCP_IOC_GETMOUNTUID2: + case NCP_IOC_SIGN_WANTED: + case NCP_IOC_GETROOT: + case NCP_IOC_SETROOT: + return 0; + default: + /* unkown IOCTL command, assume write */ + WARN_ON(); + } + return 1; +} + +int ncp_ioctl(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + int ret; + + if (ncp_ioctl_need_write(cmd)) { + /* + * inside the ioctl(), any failures which + * are because of file_permission() are + * -EACCESS, so it seems consistent to keep + * that here. + */ + if (mnt_want_write(filp->f_vfsmnt)) + return -EACCESS; + } + ret = __ncp_ioctl(inode, filp, cmd, arg); + if (ncp_ioctl_need_write(cmd) + mnt_drop_write(filp->->f_vfsmnt; + return ret; +} diff -puN fs/nfsd/vfs.c~elevate-writers-file_permission-callers fs/nfsd/vfs.c _