From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: [PATCH 22/26] sys_mknodat(): elevate write count for vfs_mknod/create() Date: Fri, 22 Jun 2007 13:03:32 -0700 Message-ID: <20070622200332.DCCD1884@kernel> References: <20070622200303.82D9CC3A@kernel> Cc: linux-fsdevel@vger.kernel.org, hch@infradead.org, viro@ftp.linux.org.uk, Dave Hansen To: akpm@osdl.org Return-path: Received: from e35.co.us.ibm.com ([32.97.110.153]:40613 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751350AbXFVUIM (ORCPT ); Fri, 22 Jun 2007 16:08:12 -0400 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e35.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id l5MK8Cfj030164 for ; Fri, 22 Jun 2007 16:08:12 -0400 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v8.3) with ESMTP id l5MK6CId212682 for ; Fri, 22 Jun 2007 14:08:12 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l5MK3Yqp003153 for ; Fri, 22 Jun 2007 14:03:35 -0600 In-Reply-To: <20070622200303.82D9CC3A@kernel> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org This takes care of all of the direct callers of vfs_mknod(). Since a few of these cases also handle normal file creation as well, this also covers some calls to vfs_create(). Signed-off-by: Dave Hansen --- lxc-dave/fs/namei.c | 12 ++++++++++++ lxc-dave/fs/nfsd/vfs.c | 8 ++++++-- lxc-dave/net/unix/af_unix.c | 4 ++++ 3 files changed, 22 insertions(+), 2 deletions(-) diff -puN fs/namei.c~18-24-sys-mknodat-elevate-write-count-for-vfs-mknod-create fs/namei.c --- lxc/fs/namei.c~18-24-sys-mknodat-elevate-write-count-for-vfs-mknod-create 2007-06-21 23:23:25.000000000 -0700 +++ lxc-dave/fs/namei.c 2007-06-21 23:23:25.000000000 -0700 @@ -1897,14 +1897,26 @@ asmlinkage long sys_mknodat(int dfd, con if (!IS_ERR(dentry)) { switch (mode & S_IFMT) { case 0: case S_IFREG: + error = mnt_want_write(nd.mnt); + if (error) + break; error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd); + mnt_drop_write(nd.mnt); break; case S_IFCHR: case S_IFBLK: + error = mnt_want_write(nd.mnt); + if (error) + break; error = vfs_mknod(nd.dentry->d_inode,dentry,mode, new_decode_dev(dev)); + mnt_drop_write(nd.mnt); break; case S_IFIFO: case S_IFSOCK: + error = mnt_want_write(nd.mnt); + if (error) + break; error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0); + mnt_drop_write(nd.mnt); break; case S_IFDIR: error = -EPERM; diff -puN fs/nfsd/vfs.c~18-24-sys-mknodat-elevate-write-count-for-vfs-mknod-create fs/nfsd/vfs.c --- lxc/fs/nfsd/vfs.c~18-24-sys-mknodat-elevate-write-count-for-vfs-mknod-create 2007-06-21 23:23:25.000000000 -0700 +++ lxc-dave/fs/nfsd/vfs.c 2007-06-21 23:23:25.000000000 -0700 @@ -1192,7 +1192,11 @@ nfsd_create(struct svc_rqst *rqstp, stru case S_IFBLK: case S_IFIFO: case S_IFSOCK: + host_err = mnt_want_write(fhp->fh_export->ex_mnt); + if (host_err) + break; host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); + mnt_drop_write(fhp->fh_export->ex_mnt); break; default: printk("nfsd: bad file type %o in nfsd_create\n", type); @@ -1811,7 +1815,7 @@ nfsd_permission(struct svc_export *exp, inode->i_mode, IS_IMMUTABLE(inode)? " immut" : "", IS_APPEND(inode)? " append" : "", - __mnt_is_readonly(exp->mnt)? " ro" : ""); + __mnt_is_readonly(exp->ex_mnt)? " ro" : ""); dprintk(" owner %d/%d user %d/%d\n", inode->i_uid, inode->i_gid, current->fsuid, current->fsgid); #endif @@ -1822,7 +1826,7 @@ nfsd_permission(struct svc_export *exp, */ if (!(acc & MAY_LOCAL_ACCESS)) if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) { - if (EX_RDONLY(exp) || __mnt_is_readonly(exp->mnt)) + if (EX_RDONLY(exp) || __mnt_is_readonly(exp->ex_mnt)) return nfserr_rofs; if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode)) return nfserr_perm; diff -puN net/unix/af_unix.c~18-24-sys-mknodat-elevate-write-count-for-vfs-mknod-create net/unix/af_unix.c --- lxc/net/unix/af_unix.c~18-24-sys-mknodat-elevate-write-count-for-vfs-mknod-create 2007-06-21 23:23:25.000000000 -0700 +++ lxc-dave/net/unix/af_unix.c 2007-06-21 23:23:25.000000000 -0700 @@ -816,7 +816,11 @@ static int unix_bind(struct socket *sock */ mode = S_IFSOCK | (SOCK_INODE(sock)->i_mode & ~current->fs->umask); + err = mnt_want_write(nd.mnt); + if (err) + goto out_mknod_dput; err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0); + mnt_drop_write(nd.mnt); if (err) goto out_mknod_dput; mutex_unlock(&nd.dentry->d_inode->i_mutex); _