Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750766AbWHBACk (ORCPT ); Tue, 1 Aug 2006 20:02:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750844AbWHBACj (ORCPT ); Tue, 1 Aug 2006 20:02:39 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:18641 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1750766AbWHAXwv (ORCPT ); Tue, 1 Aug 2006 19:52:51 -0400 Subject: [PATCH 11/28] elevate writer count for chown and friends To: linux-kernel@vger.kernel.org Cc: viro@ftp.linux.org.uk, herbert@13thfloor.at, hch@infradead.org, Dave Hansen From: Dave Hansen Date: Tue, 01 Aug 2006 16:52:48 -0700 References: <20060801235240.82ADCA42@localhost.localdomain> In-Reply-To: <20060801235240.82ADCA42@localhost.localdomain> Message-Id: <20060801235248.0893CC0F@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3682 Lines: 135 chown/chmod,etc... don't call permission in the same way that the normal "open for write" calls do. They still write to the filesystem, so bump the write count during these operations. Signed-off-by: Dave Hansen --- lxc-dave/fs/open.c | 38 +++++++++++++++++++++++++++++++++----- 1 files changed, 33 insertions(+), 5 deletions(-) diff -puN fs/open.c~C-elevate-writers-chown-and-friends fs/open.c --- lxc/fs/open.c~C-elevate-writers-chown-and-friends 2006-08-01 16:35:13.000000000 -0700 +++ lxc-dave/fs/open.c 2006-08-01 16:35:22.000000000 -0700 @@ -644,9 +644,12 @@ asmlinkage long sys_fchmod(unsigned int err = -EROFS; if (IS_RDONLY(inode)) goto out_putf; + err = mnt_want_write(file->f_vfsmnt); + if (err) + goto out_putf; err = -EPERM; if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) - goto out_putf; + goto out_drop_write; mutex_lock(&inode->i_mutex); if (mode == (mode_t) -1) mode = inode->i_mode; @@ -655,6 +658,8 @@ asmlinkage long sys_fchmod(unsigned int err = notify_change(dentry, &newattrs); mutex_unlock(&inode->i_mutex); +out_drop_write: + mnt_drop_write(file->f_vfsmnt); out_putf: fput(file); out: @@ -674,13 +679,16 @@ asmlinkage long sys_fchmodat(int dfd, co goto out; inode = nd.dentry->d_inode; + error = mnt_want_write(nd.mnt); + if (error) + goto dput_and_out; error = -EROFS; if (IS_RDONLY(inode)) - goto dput_and_out; + goto out_drop_write; error = -EPERM; if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) - goto dput_and_out; + goto out_drop_write; mutex_lock(&inode->i_mutex); if (mode == (mode_t) -1) @@ -690,6 +698,8 @@ asmlinkage long sys_fchmodat(int dfd, co error = notify_change(nd.dentry, &newattrs); mutex_unlock(&inode->i_mutex); +out_drop_write: + mnt_drop_write(nd.mnt); dput_and_out: path_release(&nd); out: @@ -715,7 +725,7 @@ static int chown_common(struct dentry * error = -EROFS; if (IS_RDONLY(inode)) goto out; - error = -EPERM; + error = -EPERM; if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) goto out; newattrs.ia_valid = ATTR_CTIME; @@ -744,7 +754,12 @@ asmlinkage long sys_chown(const char __u error = user_path_walk(filename, &nd); if (error) goto out; + error = mnt_want_write(nd.mnt); + if (error) + goto out_release; error = chown_common(nd.dentry, user, group); + mnt_drop_write(nd.mnt); +out_release: path_release(&nd); out: return error; @@ -764,7 +779,12 @@ asmlinkage long sys_fchownat(int dfd, co error = __user_walk_fd(dfd, filename, follow, &nd); if (error) goto out; + error = mnt_want_write(nd.mnt); + if (error) + goto out_release; error = chown_common(nd.dentry, user, group); + mnt_drop_write(nd.mnt); +out_release: path_release(&nd); out: return error; @@ -778,7 +798,11 @@ asmlinkage long sys_lchown(const char __ error = user_path_walk_link(filename, &nd); if (error) goto out; + error = mnt_want_write(nd.mnt); + if (error) + goto out_release; error = chown_common(nd.dentry, user, group); +out_release: path_release(&nd); out: return error; @@ -794,10 +818,14 @@ asmlinkage long sys_fchown(unsigned int file = fget(fd); if (!file) goto out; - + error = mnt_want_write(file->f_vfsmnt); + if (error) + goto out_fput; dentry = file->f_dentry; audit_inode(NULL, dentry->d_inode); error = chown_common(dentry, user, group); + mnt_drop_write(file->f_vfsmnt); +out_fput: fput(file); out: return error; _ - 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/