1/* SPDX-License-Identifier: GPL-2.0 */
  2#include <linux/mount.h>
  3#include <linux/seq_file.h>
  4#include <linux/poll.h>
  5#include <linux/ns_common.h>
  6#include <linux/fs_pin.h>
  7
  8struct mnt_namespace {
 
  9	struct ns_common	ns;
 10	struct mount *	root;
 11	struct rb_root		mounts; /* Protected by namespace_sem */
 
 
 
 
 
 
 12	struct user_namespace	*user_ns;
 13	struct ucounts		*ucounts;
 14	u64			seq;	/* Sequence number to prevent loops */
 15	wait_queue_head_t poll;
 16	u64 event;
 17	unsigned int		nr_mounts; /* # of mounts in the namespace */
 18	unsigned int		pending_mounts;
 19	struct rb_node		mnt_ns_tree_node; /* node in the mnt_ns_tree */
 20	refcount_t		passive; /* number references not pinning @mounts */
 21} __randomize_layout;
 22
 23struct mnt_pcp {
 24	int mnt_count;
 25	int mnt_writers;
 26};
 27
 28struct mountpoint {
 29	struct hlist_node m_hash;
 30	struct dentry *m_dentry;
 31	struct hlist_head m_list;
 32	int m_count;
 33};
 34
 35struct mount {
 36	struct hlist_node mnt_hash;
 37	struct mount *mnt_parent;
 38	struct dentry *mnt_mountpoint;
 39	struct vfsmount mnt;
 40	union {
 41		struct rb_node mnt_node; /* node in the ns->mounts rbtree */
 42		struct rcu_head mnt_rcu;
 43		struct llist_node mnt_llist;
 44	};
 45#ifdef CONFIG_SMP
 46	struct mnt_pcp __percpu *mnt_pcp;
 47#else
 48	int mnt_count;
 49	int mnt_writers;
 50#endif
 51	struct list_head mnt_mounts;	/* list of children, anchored here */
 52	struct list_head mnt_child;	/* and going through their mnt_child */
 53	struct list_head mnt_instance;	/* mount instance on sb->s_mounts */
 54	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */
 55	struct list_head mnt_list;
 56	struct list_head mnt_expire;	/* link in fs-specific expiry list */
 57	struct list_head mnt_share;	/* circular list of shared mounts */
 58	struct list_head mnt_slave_list;/* list of slave mounts */
 59	struct list_head mnt_slave;	/* slave list entry */
 60	struct mount *mnt_master;	/* slave is on master->mnt_slave_list */
 61	struct mnt_namespace *mnt_ns;	/* containing namespace */
 62	struct mountpoint *mnt_mp;	/* where is it mounted */
 63	union {
 64		struct hlist_node mnt_mp_list;	/* list mounts with the same mountpoint */
 65		struct hlist_node mnt_umount;
 66	};
 67	struct list_head mnt_umounting; /* list entry for umount propagation */
 68#ifdef CONFIG_FSNOTIFY
 69	struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
 70	__u32 mnt_fsnotify_mask;
 71#endif
 72	int mnt_id;			/* mount identifier, reused */
 73	u64 mnt_id_unique;		/* mount ID unique until reboot */
 74	int mnt_group_id;		/* peer group identifier */
 75	int mnt_expiry_mark;		/* true if marked for expiry */
 76	struct hlist_head mnt_pins;
 77	struct hlist_head mnt_stuck_children;
 78} __randomize_layout;
 79
 80#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
 81
 82static inline struct mount *real_mount(struct vfsmount *mnt)
 83{
 84	return container_of(mnt, struct mount, mnt);
 85}
 86
 87static inline int mnt_has_parent(struct mount *mnt)
 88{
 89	return mnt != mnt->mnt_parent;
 90}
 91
 92static inline int is_mounted(struct vfsmount *mnt)
 93{
 94	/* neither detached nor internal? */
 95	return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
 96}
 97
 98extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
 99
100extern int __legitimize_mnt(struct vfsmount *, unsigned);
 
101
102static inline bool __path_is_mountpoint(const struct path *path)
103{
104	struct mount *m = __lookup_mnt(path->mnt, path->dentry);
105	return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
106}
107
108extern void __detach_mounts(struct dentry *dentry);
109
110static inline void detach_mounts(struct dentry *dentry)
111{
112	if (!d_mountpoint(dentry))
113		return;
114	__detach_mounts(dentry);
115}
116
117static inline void get_mnt_ns(struct mnt_namespace *ns)
118{
119	refcount_inc(&ns->ns.count);
120}
121
122extern seqlock_t mount_lock;
123
 
 
 
 
 
 
 
 
 
 
124struct proc_mounts {
125	struct mnt_namespace *ns;
126	struct path root;
127	int (*show)(struct seq_file *, struct vfsmount *);
 
128};
129
130extern const struct seq_operations mounts_op;
131
132extern bool __is_local_mountpoint(struct dentry *dentry);
133static inline bool is_local_mountpoint(struct dentry *dentry)
134{
135	if (!d_mountpoint(dentry))
136		return false;
137
138	return __is_local_mountpoint(dentry);
139}
140
141static inline bool is_anon_ns(struct mnt_namespace *ns)
142{
143	return ns->seq == 0;
144}
145
146static inline bool mnt_ns_attached(const struct mount *mnt)
147{
148	return !RB_EMPTY_NODE(&mnt->mnt_node);
149}
150
151static inline void move_from_ns(struct mount *mnt, struct list_head *dt_list)
152{
153	WARN_ON(!mnt_ns_attached(mnt));
154	rb_erase(&mnt->mnt_node, &mnt->mnt_ns->mounts);
155	RB_CLEAR_NODE(&mnt->mnt_node);
156	list_add_tail(&mnt->mnt_list, dt_list);
157}
158
159bool has_locked_children(struct mount *mnt, struct dentry *dentry);
160struct mnt_namespace *__lookup_next_mnt_ns(struct mnt_namespace *mnt_ns, bool previous);
161static inline struct mnt_namespace *lookup_next_mnt_ns(struct mnt_namespace *mntns)
162{
163	return __lookup_next_mnt_ns(mntns, false);
164}
165static inline struct mnt_namespace *lookup_prev_mnt_ns(struct mnt_namespace *mntns)
166{
167	return __lookup_next_mnt_ns(mntns, true);
168}
169static inline struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
170{
171	return container_of(ns, struct mnt_namespace, ns);
172}

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#include <linux/mount.h>
  3#include <linux/seq_file.h>
  4#include <linux/poll.h>
  5#include <linux/ns_common.h>
  6#include <linux/fs_pin.h>
  7
  8struct mnt_namespace {
  9	atomic_t		count;
 10	struct ns_common	ns;
 11	struct mount *	root;
 12	/*
 13	 * Traversal and modification of .list is protected by either
 14	 * - taking namespace_sem for write, OR
 15	 * - taking namespace_sem for read AND taking .ns_lock.
 16	 */
 17	struct list_head	list;
 18	spinlock_t		ns_lock;
 19	struct user_namespace	*user_ns;
 20	struct ucounts		*ucounts;
 21	u64			seq;	/* Sequence number to prevent loops */
 22	wait_queue_head_t poll;
 23	u64 event;
 24	unsigned int		mounts; /* # of mounts in the namespace */
 25	unsigned int		pending_mounts;
 
 
 26} __randomize_layout;
 27
 28struct mnt_pcp {
 29	int mnt_count;
 30	int mnt_writers;
 31};
 32
 33struct mountpoint {
 34	struct hlist_node m_hash;
 35	struct dentry *m_dentry;
 36	struct hlist_head m_list;
 37	int m_count;
 38};
 39
 40struct mount {
 41	struct hlist_node mnt_hash;
 42	struct mount *mnt_parent;
 43	struct dentry *mnt_mountpoint;
 44	struct vfsmount mnt;
 45	union {
 
 46		struct rcu_head mnt_rcu;
 47		struct llist_node mnt_llist;
 48	};
 49#ifdef CONFIG_SMP
 50	struct mnt_pcp __percpu *mnt_pcp;
 51#else
 52	int mnt_count;
 53	int mnt_writers;
 54#endif
 55	struct list_head mnt_mounts;	/* list of children, anchored here */
 56	struct list_head mnt_child;	/* and going through their mnt_child */
 57	struct list_head mnt_instance;	/* mount instance on sb->s_mounts */
 58	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */
 59	struct list_head mnt_list;
 60	struct list_head mnt_expire;	/* link in fs-specific expiry list */
 61	struct list_head mnt_share;	/* circular list of shared mounts */
 62	struct list_head mnt_slave_list;/* list of slave mounts */
 63	struct list_head mnt_slave;	/* slave list entry */
 64	struct mount *mnt_master;	/* slave is on master->mnt_slave_list */
 65	struct mnt_namespace *mnt_ns;	/* containing namespace */
 66	struct mountpoint *mnt_mp;	/* where is it mounted */
 67	union {
 68		struct hlist_node mnt_mp_list;	/* list mounts with the same mountpoint */
 69		struct hlist_node mnt_umount;
 70	};
 71	struct list_head mnt_umounting; /* list entry for umount propagation */
 72#ifdef CONFIG_FSNOTIFY
 73	struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
 74	__u32 mnt_fsnotify_mask;
 75#endif
 76	int mnt_id;			/* mount identifier */
 
 77	int mnt_group_id;		/* peer group identifier */
 78	int mnt_expiry_mark;		/* true if marked for expiry */
 79	struct hlist_head mnt_pins;
 80	struct hlist_head mnt_stuck_children;
 81} __randomize_layout;
 82
 83#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
 84
 85static inline struct mount *real_mount(struct vfsmount *mnt)
 86{
 87	return container_of(mnt, struct mount, mnt);
 88}
 89
 90static inline int mnt_has_parent(struct mount *mnt)
 91{
 92	return mnt != mnt->mnt_parent;
 93}
 94
 95static inline int is_mounted(struct vfsmount *mnt)
 96{
 97	/* neither detached nor internal? */
 98	return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
 99}
100
101extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
102
103extern int __legitimize_mnt(struct vfsmount *, unsigned);
104extern bool legitimize_mnt(struct vfsmount *, unsigned);
105
106static inline bool __path_is_mountpoint(const struct path *path)
107{
108	struct mount *m = __lookup_mnt(path->mnt, path->dentry);
109	return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
110}
111
112extern void __detach_mounts(struct dentry *dentry);
113
114static inline void detach_mounts(struct dentry *dentry)
115{
116	if (!d_mountpoint(dentry))
117		return;
118	__detach_mounts(dentry);
119}
120
121static inline void get_mnt_ns(struct mnt_namespace *ns)
122{
123	atomic_inc(&ns->count);
124}
125
126extern seqlock_t mount_lock;
127
128static inline void lock_mount_hash(void)
129{
130	write_seqlock(&mount_lock);
131}
132
133static inline void unlock_mount_hash(void)
134{
135	write_sequnlock(&mount_lock);
136}
137
138struct proc_mounts {
139	struct mnt_namespace *ns;
140	struct path root;
141	int (*show)(struct seq_file *, struct vfsmount *);
142	struct mount cursor;
143};
144
145extern const struct seq_operations mounts_op;
146
147extern bool __is_local_mountpoint(struct dentry *dentry);
148static inline bool is_local_mountpoint(struct dentry *dentry)
149{
150	if (!d_mountpoint(dentry))
151		return false;
152
153	return __is_local_mountpoint(dentry);
154}
155
156static inline bool is_anon_ns(struct mnt_namespace *ns)
157{
158	return ns->seq == 0;
159}
160
161extern void mnt_cursor_del(struct mnt_namespace *ns, struct mount *cursor);