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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - fs/pnode.c
4 * (C) Copyright IBM Corporation 2005.
5 * Released under GPL v2.
6 * Author : Ram Pai (linuxram@us.ibm.com)
9 #include <linux/namespace.h>
10 #include <linux/mount.h>
14 /* return the next shared peer mount of @p */
15 static inline struct vfsmount
*next_peer(struct vfsmount
*p
)
17 return list_entry(p
->mnt_share
.next
, struct vfsmount
, mnt_share
);
20 void change_mnt_propagation(struct vfsmount
*mnt
, int type
)
22 if (type
== MS_SHARED
) {
25 list_del_init(&mnt
->mnt_share
);
26 mnt
->mnt_flags
&= ~MNT_PNODE_MASK
;
31 * get the next mount in the propagation tree.
32 * @m: the mount seen last
33 * @origin: the original mount from where the tree walk initiated
35 static struct vfsmount
*propagation_next(struct vfsmount
*m
,
36 struct vfsmount
*origin
)
45 * mount 'source_mnt' under the destination 'dest_mnt' at
46 * dentry 'dest_dentry'. And propagate that mount to
47 * all the peer and slave mounts of 'dest_mnt'.
48 * Link all the new mounts into a propagation tree headed at
49 * source_mnt. Also link all the new mounts using ->mnt_list
50 * headed at source_mnt's ->mnt_list
52 * @dest_mnt: destination mount.
53 * @dest_dentry: destination dentry.
54 * @source_mnt: source mount.
55 * @tree_list : list of heads of trees to be attached.
57 int propagate_mnt(struct vfsmount
*dest_mnt
, struct dentry
*dest_dentry
,
58 struct vfsmount
*source_mnt
, struct list_head
*tree_list
)
60 struct vfsmount
*m
, *child
;
62 struct vfsmount
*prev_dest_mnt
= dest_mnt
;
63 struct vfsmount
*prev_src_mnt
= source_mnt
;
65 LIST_HEAD(umount_list
);
67 for (m
= propagation_next(dest_mnt
, dest_mnt
); m
;
68 m
= propagation_next(m
, dest_mnt
)) {
69 int type
= CL_PROPAGATION
;
75 type
|= CL_MAKE_SHARED
;
77 if (!(child
= copy_tree(source_mnt
, source_mnt
->mnt_root
,
80 list_splice(tree_list
, tmp_list
.prev
);
84 if (is_subdir(dest_dentry
, m
->mnt_root
)) {
85 mnt_set_mountpoint(m
, dest_dentry
, child
);
86 list_add_tail(&child
->mnt_hash
, tree_list
);
89 * This can happen if the parent mount was bind mounted
90 * on some subdirectory of a shared/slave mount.
92 list_add_tail(&child
->mnt_hash
, &tmp_list
);
98 spin_lock(&vfsmount_lock
);
99 while (!list_empty(&tmp_list
)) {
100 child
= list_entry(tmp_list
.next
, struct vfsmount
, mnt_hash
);
101 list_del_init(&child
->mnt_hash
);
102 umount_tree(child
, &umount_list
);
104 spin_unlock(&vfsmount_lock
);
105 release_mounts(&umount_list
);