From: Mike Waychison <michael.waychison@sun.com>
To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: raven@themaw.net
Subject: [PATCH 16/28] VFS: Mountpoint file descriptor attach support
Date: Mon, 25 Oct 2004 10:46:39 -0400 [thread overview]
Message-ID: <10987155992813@sun.com> (raw)
In-Reply-To: <10987155691365@sun.com>
This patch allows an unattached mountfd to be attached to a directory given a
direct fd.
NOTE: Probably requires CAP_SYSADMIN.. depends on what we want the security
model to be.
Signed-off-by: Mike Waychison <michael.waychison@sun.com>
---
fs/mountfd.c | 35 +++++++++++++++++++++++++++++++++++
include/linux/fs.h | 1 +
2 files changed, 36 insertions(+)
Index: linux-2.6.9-quilt/fs/mountfd.c
===================================================================
--- linux-2.6.9-quilt.orig/fs/mountfd.c 2004-10-22 17:17:41.367175376 -0400
+++ linux-2.6.9-quilt/fs/mountfd.c 2004-10-22 17:17:42.011077488 -0400
@@ -5,6 +5,7 @@
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/security.h>
+#include <linux/namei.h>
#define MFDFS_MAGIC 0x4A9F2E43
#define MFDFS_ROOT_INO 1
@@ -251,6 +252,38 @@ out_filp:
return error;
}
+static long mfd_attach(struct file *mountfilp, int dirfd)
+{
+ struct file *dir;
+ struct vfsmount *mnt;
+ struct nameidata nd;
+ int ret;
+
+ mnt = mntget(VFSMOUNT(mountfilp));
+
+ ret = -EBADF;
+ dir = fget(dirfd);
+ if (!dir)
+ goto out;
+
+ ret = -ENOTDIR;
+ if (!S_ISDIR(dir->f_dentry->d_inode->i_mode))
+ goto out2;
+
+ memset(&nd, 0, sizeof(nd));
+ nd.dentry = dget(dir->f_dentry);
+ nd.mnt = mntget(dir->f_vfsmnt);
+
+ ret = do_graft_mount(mnt, &nd);
+
+ path_release(&nd);
+out2:
+ put_filp(dir);
+out:
+ mntput(mnt);
+ return ret;
+}
+
static int mfd_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
@@ -263,6 +296,8 @@ static int mfd_ioctl(struct inode *inode
return mfd_umount(filp, 0);
case MOUNTFD_IOC_FORCEDUNMOUNT:
return mfd_umount(filp, MNT_FORCE);
+ case MOUNTFD_IOC_ATTACH:
+ return mfd_attach(filp, arg);
}
return -ENOTTY;
}
Index: linux-2.6.9-quilt/include/linux/fs.h
===================================================================
--- linux-2.6.9-quilt.orig/include/linux/fs.h 2004-10-22 17:17:41.369175072 -0400
+++ linux-2.6.9-quilt/include/linux/fs.h 2004-10-22 17:17:42.012077336 -0400
@@ -218,6 +218,7 @@ extern int leases_enable, dir_notify_ena
#define MOUNTFD_IOC_UNMOUNT _IO('p', 0xa1)
#define MOUNTFD_IOC_DETACH _IO('p', 0xa2)
#define MOUNTFD_IOC_FORCEDUNMOUNT _IO('p', 0xa3)
+#define MOUNTFD_IOC_ATTACH _IOW('p', 0xa4, int)
#ifdef __KERNEL__
next prev parent reply other threads:[~2004-10-25 14:46 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <10987155332448@sun.com>
2004-10-25 14:46 ` [PATCH 15/28] VFS: Mountpoint file descriptor umount support Mike Waychison
2004-10-25 14:46 ` Mike Waychison [this message]
2004-10-25 14:47 ` [PATCH 17/28] VFS: Mountpoint file descriptor walking Mike Waychison
2004-10-25 14:47 ` [PATCH 18/28] VFS: Mountpoint file descriptor read properties Mike Waychison
2004-10-25 14:48 ` [PATCH 19/28] VFS: Mountpoint file descriptor expiry support Mike Waychison
2004-10-25 14:48 ` [PATCH 20/28] HOTPLUG: call_usermodehelper callback support Mike Waychison
2004-10-25 14:49 ` [PATCH 21/28] HOTPLUG: Hack to allow for call to execve Mike Waychison
2004-10-25 14:49 ` [PATCH 22/28] VFS: Export put_namespace Mike Waychison
2004-10-25 14:50 ` [PATCH 23/28] VFS: Export get_sb_pseudo Mike Waychison
2004-10-25 14:50 ` [PATCH 24/28] VFS: Fixup for ->follow_link on root of filesystem Mike Waychison
2004-10-25 14:51 ` [PATCH 25/28] VFS: statfs(64) shouldn't follow last component symlink Mike Waychison
2004-10-25 14:51 ` [PATCH 26/28] VFS: Introduce MNT_NOFOLLOW Mike Waychison
2004-10-25 14:52 ` [PATCH 27/28] Testing syscall for expiry Mike Waychison
2004-10-25 15:01 ` Christoph Hellwig
2004-10-25 15:37 ` [PATCH 28/28] AUTOFSNG: New autofs filesystem (resend) Mike Waychison
2004-10-25 15:14 ` [PATCH 25/28] VFS: statfs(64) shouldn't follow last component symlink Christoph Hellwig
2004-10-25 15:21 ` Mike Waychison
2004-10-25 15:18 ` [PATCH 20/28] HOTPLUG: call_usermodehelper callback support Christoph Hellwig
2004-10-25 15:29 ` Mike Waychison
2004-10-26 10:28 ` [PATCH 15/28] VFS: Mountpoint file descriptor umount support Christoph Hellwig
2004-10-26 14:16 ` Mike Waychison
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