From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [PATCH 16/23] vfs: Teach fstatfs, fstatfs64, ftruncate, fchdir, fchmod, fchown to use file_hotplug_lock Date: Mon, 1 Jun 2009 14:50:41 -0700 Message-ID: <1243893048-17031-16-git-send-email-ebiederm@xmission.com> References: Cc: , , , , Hugh Dickins , Tejun Heo , Alexey Dobriyan , Linus Torvalds , Alan Cox , Greg Kroah-Hartman , Nick Piggin , Andrew Morton , Christoph Hellwig , "Eric W. Biederman" , "Eric W. Biederman" To: Al Viro Return-path: Received: from out01.mta.xmission.com ([166.70.13.231]:43424 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754792AbZFAVvA (ORCPT ); Mon, 1 Jun 2009 17:51:00 -0400 In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Eric W. Biederman Signed-off-by: Eric W. Biederman --- fs/open.c | 47 +++++++++++++++++++++++++++++++++++++++++------ 1 files changed, 41 insertions(+), 6 deletions(-) diff --git a/fs/open.c b/fs/open.c index 83d6369..354646b 100644 --- a/fs/open.c +++ b/fs/open.c @@ -167,9 +167,14 @@ SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf) file = fget(fd); if (!file) goto out; + error = -EIO; + if (!file_hotplug_read_trylock(file)) + goto out_putf; error = vfs_statfs_native(file->f_path.dentry, &tmp); if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) error = -EFAULT; + file_hotplug_read_unlock(file); +out_putf: fput(file); out: return error; @@ -188,9 +193,14 @@ SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user file = fget(fd); if (!file) goto out; + error = -EIO; + if (!file_hotplug_read_trylock(file)) + goto out_putf; error = vfs_statfs64(file->f_path.dentry, &tmp); if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) error = -EFAULT; + file_hotplug_read_unlock(file); +out_putf: fput(file); out: return error; @@ -309,6 +319,10 @@ static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) if (!file) goto out; + error = -EIO; + if (!file_hotplug_read_trylock(file)) + goto out_putf; + /* explicitly opened as large or we are on 64-bit box */ if (file->f_flags & O_LARGEFILE) small = 0; @@ -317,16 +331,16 @@ static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) inode = dentry->d_inode; error = -EINVAL; if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) - goto out_putf; + goto out_unlock; error = -EINVAL; /* Cannot ftruncate over 2^31 bytes without large file support */ if (small && length > MAX_NON_LFS) - goto out_putf; + goto out_unlock; error = -EPERM; if (IS_APPEND(inode)) - goto out_putf; + goto out_unlock; error = locks_verify_truncate(inode, file, length); if (!error) @@ -334,6 +348,9 @@ static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) ATTR_MTIME|ATTR_CTIME); if (!error) error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); + +out_unlock: + file_hotplug_read_unlock(file); out_putf: fput(file); out: @@ -560,15 +577,21 @@ SYSCALL_DEFINE1(fchdir, unsigned int, fd) if (!file) goto out; + error = -EIO; + if (!file_hotplug_read_trylock(file)) + goto out_putf; + inode = file->f_path.dentry->d_inode; error = -ENOTDIR; if (!S_ISDIR(inode->i_mode)) - goto out_putf; + goto out_unlock; error = inode_permission(inode, MAY_EXEC | MAY_ACCESS); if (!error) set_fs_pwd(current->fs, &file->f_path); +out_unlock: + file_hotplug_read_unlock(file); out_putf: fput(file); out: @@ -612,6 +635,10 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode) if (!file) goto out; + err = -EIO; + if (!file_hotplug_read_trylock(file)) + goto out_putf; + dentry = file->f_path.dentry; inode = dentry->d_inode; @@ -619,7 +646,7 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode) err = mnt_want_write_file(file); if (err) - goto out_putf; + goto out_unlock; mutex_lock(&inode->i_mutex); if (mode == (mode_t) -1) mode = inode->i_mode; @@ -628,6 +655,8 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode) err = notify_change(dentry, &newattrs); mutex_unlock(&inode->i_mutex); mnt_drop_write(file->f_path.mnt); +out_unlock: + file_hotplug_read_unlock(file); out_putf: fput(file); out: @@ -766,13 +795,19 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) if (!file) goto out; + error = -EIO; + if (!file_hotplug_read_trylock(file)) + goto out_fput; + error = mnt_want_write_file(file); if (error) - goto out_fput; + goto out_unlock; dentry = file->f_path.dentry; audit_inode(NULL, dentry); error = chown_common(dentry, user, group); mnt_drop_write(file->f_path.mnt); +out_unlock: + file_hotplug_read_unlock(file); out_fput: fput(file); out: -- 1.6.3.1.54.g99dd.dirty