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From: Dave Hansen <haveblue@us.ibm.com>
To: viro@ftp.linux.org.uk
Cc: serue@us.ibm.com, linux-kernel@vger.kernel.org,
	Dave Hansen <haveblue@us.ibm.com>
Subject: [RFC][PATCH 11/27] elevate write count during entire ncp_ioctl()
Date: Wed, 12 Jul 2006 11:17:17 -0700	[thread overview]
Message-ID: <20060712181717.D47355F7@localhost.localdomain> (raw)
In-Reply-To: <20060712181709.5C1A4353@localhost.localdomain>


Some ioctls need write access, but others don't.  Make a helper
function to decide when write access is needed, and take it.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---

 lxc-dave/fs/ncpfs/ioctl.c |   55 +++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 54 insertions(+), 1 deletion(-)

diff -puN fs/ncpfs/ioctl.c~C-elevate-writers-file_permission-callers fs/ncpfs/ioctl.c
--- lxc/fs/ncpfs/ioctl.c~C-elevate-writers-file_permission-callers	2006-07-12 11:09:15.000000000 -0700
+++ lxc-dave/fs/ncpfs/ioctl.c	2006-07-12 11:09:28.000000000 -0700
@@ -15,6 +15,7 @@
 #include <linux/ioctl.h>
 #include <linux/time.h>
 #include <linux/mm.h>
+#include <linux/mount.h>
 #include <linux/highuid.h>
 #include <linux/vmalloc.h>
 
@@ -182,7 +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);
@@ -653,3 +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 1;
+	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(1);
+	}
+	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 -EACCES;
+	}
+	ret = __ncp_ioctl(inode, filp, cmd, arg);
+	if (ncp_ioctl_need_write(cmd))
+		mnt_drop_write(filp->f_vfsmnt);
+	return ret;
+}
_

  parent reply	other threads:[~2006-07-12 18:21 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-07-12 18:17 [RFC][PATCH 00/27] Mount writer count and read-only bind mounts (v4) Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 01/27] prepare for write access checks: collapse if() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 02/27] r/o bind mount prepwork: move open_namei()'s vfs_create() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 03/27] unlink: monitor i_nlink Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 04/27] reintroduce list of vfsmounts over superblock Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 05/27] Add vfsmount writer count Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 06/27] record when sb_writer_count elevated for inode Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 08/27] increment sb writer count when nlink hits zero Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 07/27] kill open files traverse on remount ro Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 09/27] elevate writer count for chown and friends Dave Hansen
2006-07-12 18:17 ` Dave Hansen [this message]
2006-07-12 18:17 ` [RFC][PATCH 10/27] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 12/27] sys_symlinkat() elevate write count around vfs_symlink() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 13/27] elevate mount count for extended attributes Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 14/27] sys_linkat(): elevate write count around vfs_link() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 15/27] mount_is_safe(): add comment Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 16/27] unix_find_other() elevate write count for touch_atime() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 18/27] tricky: elevate write count files are open()ed Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 17/27] elevate write count over calls to vfs_rename() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 19/27] elevate writer count for do_sys_truncate() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 20/27] elevate write count for do_utimes() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 21/27] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 22/27] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 23/27] elevate mnt writers for vfs_unlink() callers Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 25/27] elevate writer count for custom 'struct file' Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 24/27] do_rmdir(): elevate write count Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 26/27] Originally from: Herbert Poetzl <herbert@13thfloor.at> Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 27/27] honor r/w changes at do_remount() time Dave Hansen
2006-07-13  7:04 ` [RFC][PATCH 00/27] Mount writer count and read-only bind mounts (v4) Ram Pai

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