From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: [RFC][PATCH 22/27] sys_mknodat(): elevate write count for vfs_mknod/create() Date: Wed, 07 Jun 2006 17:10:35 -0700 Message-ID: <20060608001035.559326ED@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 e34.co.us.ibm.com ([32.97.110.152]:15846 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S932482AbWFHAKk (ORCPT ); Wed, 7 Jun 2006 20:10:40 -0400 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e34.co.us.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id k580Aejc011382 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 7 Jun 2006 20:10:40 -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 k580AZc1278490 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 7 Jun 2006 18:10:35 -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 k580AdAU009017 for ; Wed, 7 Jun 2006 18:10:40 -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 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 --- ipc/mqueue.c | 0 lxc-dave/fs/namei.c | 48 ++++++++++++++++++++++++++++---------------- lxc-dave/fs/nfsd/vfs.c | 4 +++ lxc-dave/net/unix/af_unix.c | 4 +++ 4 files changed, 39 insertions(+), 17 deletions(-) diff -puN fs/namei.c~elevate-writers-vfs_mknod-try2 fs/namei.c --- lxc/fs/namei.c~elevate-writers-vfs_mknod-try2 2006-06-07 16:53:25.000000000 -0700 +++ lxc-dave/fs/namei.c 2006-06-07 16:53:25.000000000 -0700 @@ -1852,26 +1852,40 @@ asmlinkage long sys_mknodat(int dfd, con if (!IS_POSIXACL(nd.dentry->d_inode)) mode &= ~current->fs->umask; - if (!IS_ERR(dentry)) { - switch (mode & S_IFMT) { - case 0: case S_IFREG: - error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd); - break; - case S_IFCHR: case S_IFBLK: - error = vfs_mknod(nd.dentry->d_inode,dentry,mode, - new_decode_dev(dev)); - break; - case S_IFIFO: case S_IFSOCK: - error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0); + if (IS_ERR(dentry)) + goto out_unlock; + error = mnt_want_write(nd.mnt); + if (error) + goto out_dput; + switch (mode & S_IFMT) { + case 0: case S_IFREG: + error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd); + break; + case S_IFCHR: case S_IFBLK: + error = mnt_want_write(nd.mnt); + if (error) break; - case S_IFDIR: - error = -EPERM; + 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; - default: - error = -EINVAL; - } - dput(dentry); + error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0); + mnt_drop_write(nd.mnt); + break; + case S_IFDIR: + error = -EPERM; + break; + default: + error = -EINVAL; } + mnt_drop_write(nd.mnt); +out_dput: + dput(dentry); +out_unlock: mutex_unlock(&nd.dentry->d_inode->i_mutex); path_release(&nd); out: diff -puN fs/nfsd/vfs.c~elevate-writers-vfs_mknod-try2 fs/nfsd/vfs.c --- lxc/fs/nfsd/vfs.c~elevate-writers-vfs_mknod-try2 2006-06-07 16:53:25.000000000 -0700 +++ lxc-dave/fs/nfsd/vfs.c 2006-06-07 16:53:25.000000000 -0700 @@ -1153,6 +1153,9 @@ nfsd_create(struct svc_rqst *rqstp, stru /* * Get the dir op function pointer. */ + err = mnt_want_write(fhp->fh_export->ex_mnt); + if (err) + goto out_nfserr; err = nfserr_perm; switch (type) { case S_IFREG: @@ -1171,6 +1174,7 @@ nfsd_create(struct svc_rqst *rqstp, stru printk("nfsd: bad file type %o in nfsd_create\n", type); err = -EINVAL; } + mnt_drop_write(fhp->fh_export->ex_mnt); if (err < 0) goto out_nfserr; diff -puN net/unix/af_unix.c~elevate-writers-vfs_mknod-try2 net/unix/af_unix.c --- lxc/net/unix/af_unix.c~elevate-writers-vfs_mknod-try2 2006-06-07 16:53:25.000000000 -0700 +++ lxc-dave/net/unix/af_unix.c 2006-06-07 16:53:25.000000000 -0700 @@ -789,7 +789,11 @@ 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); diff -puN ipc/mqueue.c~elevate-writers-vfs_mknod-try2 ipc/mqueue.c diff -L xattr.patch -puN /dev/null /dev/null _