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Commit 07b20889 authored by Ram Pai's avatar Ram Pai Committed by Linus Torvalds
Browse files

[PATCH] beginning of the shared-subtree proper 



A private mount does not forward or receive propagation.  This patch
provides user the ability to convert any mount to private.

Signed-off-by: default avatarRam Pai <linuxram@us.ibm.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 390c6843

fs/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -10,7 +10,7 @@ obj-y := open.o read_write.o file_table.o buffer.o bio.o super.o \ 
		ioctl.o readdir.o select.o fifo.o locks.o dcache.o inode.o \

		attr.o bad_inode.o file.o filesystems.o namespace.o aio.o \

		seq_file.o xattr.o libfs.o fs-writeback.o mpage.o direct-io.o \

		ioprio.o

		ioprio.o pnode.o



obj-$(CONFIG_INOTIFY)		+= inotify.o

obj-$(CONFIG_EPOLL)		+= eventpoll.o

fs/namespace.c

+24 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/mount.h>

#include <asm/uaccess.h>

#include <asm/unistd.h>

#include "pnode.h"



extern int __init init_rootfs(void);
@@ -662,6 +663,27 @@ static int graft_tree(struct vfsmount *mnt, struct nameidata *nd) 
	return err;

}



/*

 * recursively change the type of the mountpoint.

 */

static int do_change_type(struct nameidata *nd, int flag)

{

	struct vfsmount *m, *mnt = nd->mnt;

	int recurse = flag & MS_REC;

	int type = flag & ~MS_REC;



	if (nd->dentry != nd->mnt->mnt_root)

		return -EINVAL;



	down_write(&namespace_sem);

	spin_lock(&vfsmount_lock);

	for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL))

		change_mnt_propagation(m, type);

	spin_unlock(&vfsmount_lock);

	up_write(&namespace_sem);

	return 0;

}



/*

 * do loopback mount.

 */
@@ -1091,6 +1113,8 @@ long do_mount(char *dev_name, char *dir_name, char *type_page, 
				    data_page);

	else if (flags & MS_BIND)

		retval = do_loopback(&nd, dev_name, flags & MS_REC);

	else if (flags & MS_PRIVATE)

		retval = do_change_type(&nd, flags);

	else if (flags & MS_MOVE)

		retval = do_move_mount(&nd, dev_name);

	else

fs/pnode.c

0 → 100644
+17 −0
Original line number Diff line number Diff line 
/*

 *  linux/fs/pnode.c

 *

 * (C) Copyright IBM Corporation 2005.

 *	Released under GPL v2.

 *	Author : Ram Pai (linuxram@us.ibm.com)

 *

 */

#include <linux/namespace.h>

#include <linux/mount.h>

#include <linux/fs.h>

#include "pnode.h"



void change_mnt_propagation(struct vfsmount *mnt, int type)

{

	mnt->mnt_flags &= ~MNT_PNODE_MASK;

}

fs/pnode.h

0 → 100644
+14 −0
Original line number Diff line number Diff line 
/*

 *  linux/fs/pnode.h

 *

 * (C) Copyright IBM Corporation 2005.

 *	Released under GPL v2.

 *

 */

#ifndef _LINUX_PNODE_H

#define _LINUX_PNODE_H



#include <linux/list.h>

#include <linux/mount.h>

void change_mnt_propagation(struct vfsmount *, int);

#endif /* _LINUX_PNODE_H */

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -104,6 +104,7 @@ extern int dir_notify_enable; 
#define MS_MOVE		8192

#define MS_REC		16384

#define MS_VERBOSE	32768

#define MS_PRIVATE	(1<<18)	/* change to private */

#define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */

#define MS_ACTIVE	(1<<30)

#define MS_NOUSER	(1<<31)