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);

 
  1#include <linux/mount.h>
  2#include <linux/seq_file.h>
  3#include <linux/poll.h>
 
 
  4
  5struct mnt_namespace {
  6	atomic_t		count;
  7	unsigned int		proc_inum;
  8	struct mount *	root;
 
 
 
 
 
  9	struct list_head	list;
 
 10	struct user_namespace	*user_ns;
 
 11	u64			seq;	/* Sequence number to prevent loops */
 12	wait_queue_head_t poll;
 13	u64 event;
 14};
 
 
 15
 16struct mnt_pcp {
 17	int mnt_count;
 18	int mnt_writers;
 19};
 20
 21struct mountpoint {
 22	struct hlist_node m_hash;
 23	struct dentry *m_dentry;
 
 24	int m_count;
 25};
 26
 27struct mount {
 28	struct hlist_node mnt_hash;
 29	struct mount *mnt_parent;
 30	struct dentry *mnt_mountpoint;
 31	struct vfsmount mnt;
 32	struct rcu_head mnt_rcu;
 
 
 
 33#ifdef CONFIG_SMP
 34	struct mnt_pcp __percpu *mnt_pcp;
 35#else
 36	int mnt_count;
 37	int mnt_writers;
 38#endif
 39	struct list_head mnt_mounts;	/* list of children, anchored here */
 40	struct list_head mnt_child;	/* and going through their mnt_child */
 41	struct list_head mnt_instance;	/* mount instance on sb->s_mounts */
 42	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */
 43	struct list_head mnt_list;
 44	struct list_head mnt_expire;	/* link in fs-specific expiry list */
 45	struct list_head mnt_share;	/* circular list of shared mounts */
 46	struct list_head mnt_slave_list;/* list of slave mounts */
 47	struct list_head mnt_slave;	/* slave list entry */
 48	struct mount *mnt_master;	/* slave is on master->mnt_slave_list */
 49	struct mnt_namespace *mnt_ns;	/* containing namespace */
 50	struct mountpoint *mnt_mp;	/* where is it mounted */
 
 
 
 
 
 51#ifdef CONFIG_FSNOTIFY
 52	struct hlist_head mnt_fsnotify_marks;
 53	__u32 mnt_fsnotify_mask;
 54#endif
 55	int mnt_id;			/* mount identifier */
 56	int mnt_group_id;		/* peer group identifier */
 57	int mnt_expiry_mark;		/* true if marked for expiry */
 58	int mnt_pinned;
 59	struct path mnt_ex_mountpoint;
 60};
 61
 62#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
 63
 64static inline struct mount *real_mount(struct vfsmount *mnt)
 65{
 66	return container_of(mnt, struct mount, mnt);
 67}
 68
 69static inline int mnt_has_parent(struct mount *mnt)
 70{
 71	return mnt != mnt->mnt_parent;
 72}
 73
 74static inline int is_mounted(struct vfsmount *mnt)
 75{
 76	/* neither detached nor internal? */
 77	return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
 78}
 79
 80extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
 81extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);
 82
 
 83extern bool legitimize_mnt(struct vfsmount *, unsigned);
 84
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 85static inline void get_mnt_ns(struct mnt_namespace *ns)
 86{
 87	atomic_inc(&ns->count);
 88}
 89
 90extern seqlock_t mount_lock;
 91
 92static inline void lock_mount_hash(void)
 93{
 94	write_seqlock(&mount_lock);
 95}
 96
 97static inline void unlock_mount_hash(void)
 98{
 99	write_sequnlock(&mount_lock);
100}
101
102struct proc_mounts {
103	struct seq_file m;
104	struct mnt_namespace *ns;
105	struct path root;
106	int (*show)(struct seq_file *, struct vfsmount *);
107	void *cached_mount;
108	u64 cached_event;
109	loff_t cached_index;
110};
111
112#define proc_mounts(p) (container_of((p), struct proc_mounts, m))
 
 
 
 
 
 
 
 
 
113
114extern const struct seq_operations mounts_op;