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linux/fs/pnode.h

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[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: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:07 +00:00
/*
* 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>
vfs: new internal helper: mnt_has_parent(mnt) vfsmounts have ->mnt_parent pointing either to a different vfsmount or to itself; it's never NULL and termination condition in loops traversing the tree towards root is mnt == mnt->mnt_parent. At least one place (see the next patch) is confused about what's going on; let's add an explicit helper checking it right way and use it in all places where we need it. Not that there had been too many, but... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 00:26:23 +00:00
#include "mount.h"
[PATCH] introduce shared mounts This creates shared mounts. A shared mount when bind-mounted to some mountpoint, propagates mount/umount events to each other. All the shared mounts that propagate events to each other belong to the same peer-group. Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:33 +00:00
vfs: switch pnode.h macros to struct mount * Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 06:05:37 +00:00
#define IS_MNT_SHARED(m) ((m)->mnt.mnt_flags & MNT_SHARED)
#define IS_MNT_SLAVE(m) ((m)->mnt_master)
#define IS_MNT_NEW(m) (!(m)->mnt_ns)
#define CLEAR_MNT_SHARED(m) ((m)->mnt.mnt_flags &= ~MNT_SHARED)
#define IS_MNT_UNBINDABLE(m) ((m)->mnt.mnt_flags & MNT_UNBINDABLE)
[PATCH] introduce shared mounts This creates shared mounts. A shared mount when bind-mounted to some mountpoint, propagates mount/umount events to each other. All the shared mounts that propagate events to each other belong to the same peer-group. Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:33 +00:00
[PATCH] shared mount handling: bind and rbind Implement handling of MS_BIND in presense of shared mounts (see Documentation/sharedsubtree.txt in the end of patch series for detailed description). Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:50 +00:00
#define CL_EXPIRE 0x01
[PATCH] introduce slave mounts A slave mount always has a master mount from which it receives mount/umount events. Unlike shared mount the event propagation does not flow from the slave mount to the master. Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:20:48 +00:00
#define CL_SLAVE 0x02
vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces Don't copy bind mounts of /proc/<pid>/ns/mnt between namespaces. These files hold references to a mount namespace and copying them between namespaces could result in a reference counting loop. The current mnt_ns_loop test prevents loops on the assumption that mounts don't cross between namespaces. Unfortunately unsharing a mount namespace and shared substrees can both cause mounts to propogate between mount namespaces. Add two flags CL_COPY_UNBINDABLE and CL_COPY_MNT_NS_FILE are added to control this behavior, and CL_COPY_ALL is redefined as both of them. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-30 08:35:18 +00:00
#define CL_COPY_UNBINDABLE 0x04
[PATCH] shared mount handling: bind and rbind Implement handling of MS_BIND in presense of shared mounts (see Documentation/sharedsubtree.txt in the end of patch series for detailed description). Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:50 +00:00
#define CL_MAKE_SHARED 0x08
Kill CL_PROPAGATION, sanitize fs/pnode.c:get_source() First of all, get_source() never results in CL_PROPAGATION alone. We either get CL_MAKE_SHARED (for the continuation of peer group) or CL_SLAVE (slave that is not shared) or both (beginning of peer group among slaves). Massage the code to make that explicit, kill CL_PROPAGATION test in clone_mnt() (nothing sets CL_MAKE_SHARED without CL_PROPAGATION and in clone_mnt() we are checking CL_PROPAGATION after we'd found that there's no CL_SLAVE, so the check for CL_MAKE_SHARED would do just as well). Fix comments, while we are at it... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-16 18:28:47 +00:00
#define CL_PRIVATE 0x10
vfs: Only support slave subtrees across different user namespaces Sharing mount subtress with mount namespaces created by unprivileged users allows unprivileged mounts created by unprivileged users to propagate to mount namespaces controlled by privileged users. Prevent nasty consequences by changing shared subtrees to slave subtress when an unprivileged users creates a new mount namespace. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-07-31 20:13:04 +00:00
#define CL_SHARED_TO_SLAVE 0x20
vfs: Carefully propogate mounts across user namespaces As a matter of policy MNT_READONLY should not be changable if the original mounter had more privileges than creator of the mount namespace. Add the flag CL_UNPRIVILEGED to note when we are copying a mount from a mount namespace that requires more privileges to a mount namespace that requires fewer privileges. When the CL_UNPRIVILEGED flag is set cause clone_mnt to set MNT_NO_REMOUNT if any of the mnt flags that should never be changed are set. This protects both mount propagation and the initial creation of a less privileged mount namespace. Cc: stable@vger.kernel.org Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-22 11:08:05 +00:00
#define CL_UNPRIVILEGED 0x40
vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces Don't copy bind mounts of /proc/<pid>/ns/mnt between namespaces. These files hold references to a mount namespace and copying them between namespaces could result in a reference counting loop. The current mnt_ns_loop test prevents loops on the assumption that mounts don't cross between namespaces. Unfortunately unsharing a mount namespace and shared substrees can both cause mounts to propogate between mount namespaces. Add two flags CL_COPY_UNBINDABLE and CL_COPY_MNT_NS_FILE are added to control this behavior, and CL_COPY_ALL is redefined as both of them. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-30 08:35:18 +00:00
#define CL_COPY_MNT_NS_FILE 0x80
#define CL_COPY_ALL (CL_COPY_UNBINDABLE | CL_COPY_MNT_NS_FILE)
[PATCH] shared mount handling: bind and rbind Implement handling of MS_BIND in presense of shared mounts (see Documentation/sharedsubtree.txt in the end of patch series for detailed description). Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:50 +00:00
vfs: spread struct mount - change_mnt_propagation/set_mnt_shared Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 01:43:10 +00:00
static inline void set_mnt_shared(struct mount *mnt)
[PATCH] shared mount handling: bind and rbind Implement handling of MS_BIND in presense of shared mounts (see Documentation/sharedsubtree.txt in the end of patch series for detailed description). Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:50 +00:00
{
vfs: spread struct mount - change_mnt_propagation/set_mnt_shared Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 01:43:10 +00:00
mnt->mnt.mnt_flags &= ~MNT_SHARED_MASK;
mnt->mnt.mnt_flags |= MNT_SHARED;
[PATCH] shared mount handling: bind and rbind Implement handling of MS_BIND in presense of shared mounts (see Documentation/sharedsubtree.txt in the end of patch series for detailed description). Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:50 +00:00
}
vfs: spread struct mount - change_mnt_propagation/set_mnt_shared Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 01:43:10 +00:00
void change_mnt_propagation(struct mount *, int);
get rid of full-hash scan on detaching vfsmounts Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-15 14:53:28 +00:00
int propagate_mnt(struct mount *, struct mountpoint *, struct mount *,
switch mnt_hash to hlist fixes RCU bug - walking through hlist is safe in face of element moves, since it's self-terminating. Cyclic lists are not - if we end up jumping to another hash chain, we'll loop infinitely without ever hitting the original list head. [fix for dumb braino folded] Spotted by: Max Kellermann <mk@cm4all.com> Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-03-21 01:10:51 +00:00
struct hlist_head *);
int propagate_umount(struct hlist_head *);
vfs: spread struct mount - do_umount/propagate_mount_busy Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 02:35:16 +00:00
int propagate_mount_busy(struct mount *, int);
vfs: spread struct mount - mount group id handling Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 00:54:23 +00:00
void mnt_release_group_id(struct mount *);
vfs: spread struct mount - get_dominating_id / do_make_slave next pile of horrors, similar to mnt_parent one; this time it's mnt_master. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 04:35:54 +00:00
int get_dominating_id(struct mount *mnt, const struct path *root);
vfs: spread struct mount - work with counters Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 03:37:54 +00:00
unsigned int mnt_get_count(struct mount *mnt);
get rid of full-hash scan on detaching vfsmounts Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-15 14:53:28 +00:00
void mnt_set_mountpoint(struct mount *, struct mountpoint *,
vfs: spread struct mount mnt_set_mountpoint child argument Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 02:28:22 +00:00
struct mount *);
switch unlock_mount() to namespace_unlock(), convert all umount_tree() callers which allows to kill the last argument of umount_tree() and make release_mounts() static. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-16 18:49:45 +00:00
void umount_tree(struct mount *, int);
vfs: spread struct mount - clone_mnt/copy_tree argument Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 02:24:27 +00:00
struct mount *copy_tree(struct mount *, struct dentry *, int);
vfs: spread struct mount - is_path_reachable Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-25 03:00:28 +00:00
bool is_path_reachable(struct mount *, struct dentry *,
vfs: more mnt_parent cleanups a) mount --move is checking that ->mnt_parent is non-NULL before looking if that parent happens to be shared; ->mnt_parent is never NULL and it's not even an misspelled !mnt_has_parent() b) pivot_root open-codes is_path_reachable(), poorly. c) so does path_is_under(), while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-24 00:34:49 +00:00
const struct path *root);
[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: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 22:19:07 +00:00
#endif /* _LINUX_PNODE_H */
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