Adds the ability to unclone a vfs tree. A uncloned vfs tree will not be
clonnable, and hence cannot be bind/rbind to any other mountpoint.
RP
Adds the ability to unclone a vfs tree. A uncloned vfs tree will not be
clonnable, and hence cannot be bind/rbind to any other mountpoint.
RP
fs/namespace.c | 18 +++++++++++++++++-
include/linux/fs.h | 1 +
include/linux/mount.h | 15 +++++++++++++--
3 files changed, 31 insertions(+), 3 deletions(-)
Index: 2.6.12/fs/namespace.c
===================================================================
--- 2.6.12.orig/fs/namespace.c
+++ 2.6.12/fs/namespace.c
@@ -698,6 +698,7 @@ static int do_change_type(struct nameida
int err;
if (!(flag & MS_SHARED) && !(flag & MS_PRIVATE)
+ && !(flag & MS_UNCLONE)
&& !(flag & MS_SLAVE))
return -EINVAL;
@@ -757,6 +758,11 @@ static int do_change_type(struct nameida
SET_MNT_PRIVATE(m);
break;
+ case MS_UNCLONE:
+ if(m->mnt_pnode)
+ pnode_disassociate_mnt(m);
+ SET_MNT_UNCLONABLE(m);
+ break;
}
}
spin_unlock(&vfsmount_lock);
@@ -1197,7 +1203,8 @@ long do_mount(char * dev_name, char * di
data_page);
else if (flags & MS_BIND)
retval = do_loopback(&nd, dev_name, flags & MS_REC);
- else if (flags & MS_SHARED || flags & MS_PRIVATE || flags & MS_SLAVE)
+ else if (flags & MS_SHARED || flags & MS_UNCLONE ||
+ flags & MS_PRIVATE || flags & MS_SLAVE)
retval = do_change_type(&nd, flags);
else if (flags & MS_MOVE)
retval = do_move_mount(&nd, dev_name);
Index: 2.6.12/include/linux/fs.h
===================================================================
--- 2.6.12.orig/include/linux/fs.h
+++ 2.6.12/include/linux/fs.h
@@ -102,6 +102,7 @@ extern int dir_notify_enable;
#define MS_MOVE 8192
#define MS_REC 16384
#define MS_VERBOSE 32768
+#define MS_UNCLONE 131072
#define MS_PRIVATE 262144
#define MS_SLAVE 524288
#define MS_SHARED 1048576
Index: 2.6.12/include/linux/mount.h
===================================================================
--- 2.6.12.orig/include/linux/mount.h
+++ 2.6.12/include/linux/mount.h
@@ -21,28 +21,39 @@
#define MNT_NOEXEC 0x04
#define MNT_PRIVATE 0x10 /* if the vfsmount is private, by default it is private*/
#define MNT_SLAVE 0x20 /* if the vfsmount is a slave mount of its pnode */
-#define MNT_SHARED 0x40 /* if the vfsmount is a slave mount of its pnode */
+#define MNT_SHARED 0x40 /* if the vfsmount is a shared mount */
+#define MNT_UNCLONABLE 0x80 /* if the vfsmount is unclonable */
#define MNT_PNODE_MASK 0xf0 /* propogation flag mask */
+#define IS_MNT_UNCLONABLE(mnt) (mnt->mnt_flags&MNT_UNCLONABLE)
#define IS_MNT_SHARED(mnt) (mnt->mnt_flags&MNT_SHARED)
#define IS_MNT_SLAVE(mnt) (mnt->mnt_flags&MNT_SLAVE)
#define IS_MNT_PRIVATE(mnt) (mnt->mnt_flags&MNT_PRIVATE)
#define CLEAR_MNT_SHARED(mnt) (mnt->mnt_flags &= ~(MNT_PNODE_MASK & MNT_SHARED))
#define CLEAR_MNT_PRIVATE(mnt) (mnt->mnt_flags &= ~(MNT_PNODE_MASK & MNT_PRIVATE))
+#define CLEAR_MNT_UNCLONABLE(mnt) (mnt->mnt_flags &= ~(MNT_PNODE_MASK & MNT_UNCLONABLE))
#define CLEAR_MNT_SLAVE(mnt) (mnt->mnt_flags &= ~(MNT_PNODE_MASK & MNT_SLAVE))
//TOBEDONE WRITE BETTER MACROS. ..
#define SET_MNT_SHARED(mnt) (mnt->mnt_flags |= (MNT_PNODE_MASK & MNT_SHARED),\
CLEAR_MNT_PRIVATE(mnt), \
- CLEAR_MNT_SLAVE(mnt))
+ CLEAR_MNT_SLAVE(mnt), \
+ CLEAR_MNT_UNCLONABLE(mnt))
#define SET_MNT_PRIVATE(mnt) (mnt->mnt_flags |= (MNT_PNODE_MASK & MNT_PRIVATE), \
CLEAR_MNT_SLAVE(mnt), \
CLEAR_MNT_SHARED(mnt), \
+ CLEAR_MNT_UNCLONABLE(mnt),\
+ mnt->mnt_pnode = NULL)
+#define SET_MNT_UNCLONABLE(mnt) (mnt->mnt_flags |= (MNT_PNODE_MASK & MNT_UNCLONABLE), \
+ CLEAR_MNT_SLAVE(mnt),\
+ CLEAR_MNT_SHARED(mnt),\
+ CLEAR_MNT_PRIVATE(mnt),\
mnt->mnt_pnode = NULL)
#define SET_MNT_SLAVE(mnt) (mnt->mnt_flags |= (MNT_PNODE_MASK & MNT_SLAVE), \
CLEAR_MNT_PRIVATE(mnt), \
- CLEAR_MNT_SHARED(mnt))
+ CLEAR_MNT_SHARED(mnt), \
+ CLEAR_MNT_UNCLONABLE(mnt))
struct vfsmount
{
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