[linux-2.6-block.git] / fs / mount.h

/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/mount.h>
#include <linux/seq_file.h>
#include <linux/poll.h>
#include <linux/ns_common.h>
#include <linux/fs_pin.h>

extern struct list_head notify_list;

struct mnt_namespace {
	struct ns_common	ns;
	struct mount *	root;
	struct {
		struct rb_root	mounts;		 /* Protected by namespace_sem */
		struct rb_node	*mnt_last_node;	 /* last (rightmost) mount in the rbtree */
		struct rb_node	*mnt_first_node; /* first (leftmost) mount in the rbtree */
	};
	struct user_namespace	*user_ns;
	struct ucounts		*ucounts;
	u64			seq;	/* Sequence number to prevent loops */
	union {
		wait_queue_head_t	poll;
		struct rcu_head		mnt_ns_rcu;
	};
	u64			seq_origin; /* Sequence number of origin mount namespace */
	u64 event;
#ifdef CONFIG_FSNOTIFY
	__u32			n_fsnotify_mask;
	struct fsnotify_mark_connector __rcu *n_fsnotify_marks;
#endif
	unsigned int		nr_mounts; /* # of mounts in the namespace */
	unsigned int		pending_mounts;
	struct rb_node		mnt_ns_tree_node; /* node in the mnt_ns_tree */
	struct list_head	mnt_ns_list; /* entry in the sequential list of mounts namespace */
	refcount_t		passive; /* number references not pinning @mounts */
} __randomize_layout;

struct mnt_pcp {
	int mnt_count;
	int mnt_writers;
};

struct mountpoint {
	struct hlist_node m_hash;
	struct dentry *m_dentry;
	struct hlist_head m_list;
	int m_count;
};

struct mount {
	struct hlist_node mnt_hash;
	struct mount *mnt_parent;
	struct dentry *mnt_mountpoint;
	struct vfsmount mnt;
	union {
		struct rb_node mnt_node; /* node in the ns->mounts rbtree */
		struct rcu_head mnt_rcu;
		struct llist_node mnt_llist;
	};
#ifdef CONFIG_SMP
	struct mnt_pcp __percpu *mnt_pcp;
#else
	int mnt_count;
	int mnt_writers;
#endif
	struct list_head mnt_mounts;	/* list of children, anchored here */
	struct list_head mnt_child;	/* and going through their mnt_child */
	struct list_head mnt_instance;	/* mount instance on sb->s_mounts */
	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */
	struct list_head mnt_list;
	struct list_head mnt_expire;	/* link in fs-specific expiry list */
	struct list_head mnt_share;	/* circular list of shared mounts */
	struct list_head mnt_slave_list;/* list of slave mounts */
	struct list_head mnt_slave;	/* slave list entry */
	struct mount *mnt_master;	/* slave is on master->mnt_slave_list */
	struct mnt_namespace *mnt_ns;	/* containing namespace */
	struct mountpoint *mnt_mp;	/* where is it mounted */
	union {
		struct hlist_node mnt_mp_list;	/* list mounts with the same mountpoint */
		struct hlist_node mnt_umount;
	};
	struct list_head mnt_umounting; /* list entry for umount propagation */
#ifdef CONFIG_FSNOTIFY
	struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
	__u32 mnt_fsnotify_mask;
	struct list_head to_notify;	/* need to queue notification */
	struct mnt_namespace *prev_ns;	/* previous namespace (NULL if none) */
#endif
	int mnt_id;			/* mount identifier, reused */
	u64 mnt_id_unique;		/* mount ID unique until reboot */
	int mnt_group_id;		/* peer group identifier */
	int mnt_expiry_mark;		/* true if marked for expiry */
	struct hlist_head mnt_pins;
	struct hlist_head mnt_stuck_children;
} __randomize_layout;

#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */

static inline struct mount *real_mount(struct vfsmount *mnt)
{
	return container_of(mnt, struct mount, mnt);
}

static inline int mnt_has_parent(struct mount *mnt)
{
	return mnt != mnt->mnt_parent;
}

static inline int is_mounted(struct vfsmount *mnt)
{
	/* neither detached nor internal? */
	return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
}

extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);

extern int __legitimize_mnt(struct vfsmount *, unsigned);

static inline bool __path_is_mountpoint(const struct path *path)
{
	struct mount *m = __lookup_mnt(path->mnt, path->dentry);
	return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
}

extern void __detach_mounts(struct dentry *dentry);

static inline void detach_mounts(struct dentry *dentry)
{
	if (!d_mountpoint(dentry))
		return;
	__detach_mounts(dentry);
}

static inline void get_mnt_ns(struct mnt_namespace *ns)
{
	refcount_inc(&ns->ns.count);
}

extern seqlock_t mount_lock;

struct proc_mounts {
	struct mnt_namespace *ns;
	struct path root;
	int (*show)(struct seq_file *, struct vfsmount *);
};

extern const struct seq_operations mounts_op;

extern bool __is_local_mountpoint(struct dentry *dentry);
static inline bool is_local_mountpoint(struct dentry *dentry)
{
	if (!d_mountpoint(dentry))
		return false;

	return __is_local_mountpoint(dentry);
}

static inline bool is_anon_ns(struct mnt_namespace *ns)
{
	return ns->seq == 0;
}

static inline bool mnt_ns_attached(const struct mount *mnt)
{
	return !RB_EMPTY_NODE(&mnt->mnt_node);
}

static inline bool mnt_ns_empty(const struct mnt_namespace *ns)
{
	return RB_EMPTY_ROOT(&ns->mounts);
}

static inline void move_from_ns(struct mount *mnt, struct list_head *dt_list)
{
	struct mnt_namespace *ns = mnt->mnt_ns;
	WARN_ON(!mnt_ns_attached(mnt));
	if (ns->mnt_last_node == &mnt->mnt_node)
		ns->mnt_last_node = rb_prev(&mnt->mnt_node);
	if (ns->mnt_first_node == &mnt->mnt_node)
		ns->mnt_first_node = rb_next(&mnt->mnt_node);
	rb_erase(&mnt->mnt_node, &ns->mounts);
	RB_CLEAR_NODE(&mnt->mnt_node);
	list_add_tail(&mnt->mnt_list, dt_list);
}

bool has_locked_children(struct mount *mnt, struct dentry *dentry);
struct mnt_namespace *get_sequential_mnt_ns(struct mnt_namespace *mnt_ns,
					    bool previous);

static inline struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
{
	return container_of(ns, struct mnt_namespace, ns);
}

#ifdef CONFIG_FSNOTIFY
static inline void mnt_notify_add(struct mount *m)
{
	/* Optimize the case where there are no watches */
	if ((m->mnt_ns && m->mnt_ns->n_fsnotify_marks) ||
	    (m->prev_ns && m->prev_ns->n_fsnotify_marks))
		list_add_tail(&m->to_notify, &notify_list);
	else
		m->prev_ns = m->mnt_ns;
}
#else
static inline void mnt_notify_add(struct mount *m)
{
}
#endif

struct mnt_namespace *mnt_ns_from_dentry(struct dentry *dentry);
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
b2dba1af	2	#include <linux/mount.h>
0226f492 AV	3	#include <linux/seq_file.h>
0226f492 AV	4	#include <linux/poll.h>
435d5f4b	5	#include <linux/ns_common.h>
87b95ce0	6	#include <linux/fs_pin.h>
0226f492	7
bf630c40 MS	8	extern struct list_head notify_list;
bf630c40 MS	9
0226f492	10	struct mnt_namespace {
435d5f4b	11	struct ns_common ns;
be08d6d2	12	struct mount * root;
2ce23285 CB	13	struct {
	14	struct rb_root mounts; /* Protected by namespace_sem */
	15	struct rb_node mnt_last_node; / last (rightmost) mount in the rbtree */
	16	struct rb_node mnt_first_node; / first (leftmost) mount in the rbtree */
	17	};
771b1371	18	struct user_namespace *user_ns;
537f7ccb	19	struct ucounts *ucounts;
8823c079	20	u64 seq; /* Sequence number to prevent loops */
5dcbd85d CB	21	union {
	22	wait_queue_head_t poll;
	23	struct rcu_head mnt_ns_rcu;
	24	};
3b0cdba4	25	u64 seq_origin; /* Sequence number of origin mount namespace */
c7999c36	26	u64 event;
b944249b MS	27	#ifdef CONFIG_FSNOTIFY
	28	__u32 n_fsnotify_mask;
	29	struct fsnotify_mark_connector __rcu *n_fsnotify_marks;
	30	#endif
2eea9ce4	31	unsigned int nr_mounts; /* # of mounts in the namespace */
d2921684	32	unsigned int pending_mounts;
1901c924	33	struct rb_node mnt_ns_tree_node; /* node in the mnt_ns_tree */
4368898b	34	struct list_head mnt_ns_list; /* entry in the sequential list of mounts namespace */
1901c924	35	refcount_t passive; /* number references not pinning @mounts */
3859a271	36	} __randomize_layout;
b2dba1af	37
68e8a9fe AV	38	struct mnt_pcp {
	39	int mnt_count;
	40	int mnt_writers;
	41	};
	42
84d17192	43	struct mountpoint {
0818bf27	44	struct hlist_node m_hash;
84d17192	45	struct dentry *m_dentry;
0a5eb7c8	46	struct hlist_head m_list;
84d17192 AV	47	int m_count;
	48	};
	49
7d6fec45	50	struct mount {
38129a13	51	struct hlist_node mnt_hash;
0714a533	52	struct mount *mnt_parent;
a73324da	53	struct dentry *mnt_mountpoint;
7d6fec45	54	struct vfsmount mnt;
9ea459e1	55	union {
344bac8f	56	struct rb_node mnt_node; /* node in the ns->mounts rbtree */
9ea459e1 AV	57	struct rcu_head mnt_rcu;
	58	struct llist_node mnt_llist;
	59	};
68e8a9fe AV	60	#ifdef CONFIG_SMP
68e8a9fe AV	61	struct mnt_pcp __percpu *mnt_pcp;
68e8a9fe AV	62	#else
	63	int mnt_count;
	64	int mnt_writers;
	65	#endif
6b41d536 AV	66	struct list_head mnt_mounts; /* list of children, anchored here */
6b41d536 AV	67	struct list_head mnt_child; /* and going through their mnt_child */
39f7c4db	68	struct list_head mnt_instance; /* mount instance on sb->s_mounts */
52ba1621	69	const char mnt_devname; / Name of device e.g. /dev/dsk/hda1 */
344bac8f	70	struct list_head mnt_list;
6776db3d AV	71	struct list_head mnt_expire; /* link in fs-specific expiry list */
	72	struct list_head mnt_share; /* circular list of shared mounts */
	73	struct list_head mnt_slave_list;/* list of slave mounts */
	74	struct list_head mnt_slave; /* slave list entry */
32301920	75	struct mount mnt_master; / slave is on master->mnt_slave_list */
143c8c91	76	struct mnt_namespace mnt_ns; / containing namespace */
84d17192	77	struct mountpoint mnt_mp; / where is it mounted */
56cbb429 AV	78	union {
	79	struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
	80	struct hlist_node mnt_umount;
	81	};
99b19d16	82	struct list_head mnt_umounting; /* list entry for umount propagation */
c63181e6	83	#ifdef CONFIG_FSNOTIFY
08991e83	84	struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
c63181e6	85	__u32 mnt_fsnotify_mask;
bf630c40 MS	86	struct list_head to_notify; /* need to queue notification */
bf630c40 MS	87	struct mnt_namespace prev_ns; / previous namespace (NULL if none) */
c63181e6	88	#endif
98d2b430 MS	89	int mnt_id; /* mount identifier, reused */
98d2b430 MS	90	u64 mnt_id_unique; /* mount ID unique until reboot */
15169fe7	91	int mnt_group_id; /* peer group identifier */
863d684f	92	int mnt_expiry_mark; /* true if marked for expiry */
215752fc	93	struct hlist_head mnt_pins;
56cbb429	94	struct hlist_head mnt_stuck_children;
3859a271	95	} __randomize_layout;
7d6fec45	96
f7a99c5b AV	97	#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
f7a99c5b AV	98
7d6fec45 AV	99	static inline struct mount real_mount(struct vfsmount mnt)
	100	{
	101	return container_of(mnt, struct mount, mnt);
	102	}
	103
676da58d	104	static inline int mnt_has_parent(struct mount *mnt)
b2dba1af	105	{
0714a533	106	return mnt != mnt->mnt_parent;
b2dba1af	107	}
c7105365	108
f7a99c5b AV	109	static inline int is_mounted(struct vfsmount *mnt)
	110	{
	111	/* neither detached nor internal? */
260a459d	112	return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
f7a99c5b AV	113	}
f7a99c5b AV	114
474279dc	115	extern struct mount __lookup_mnt(struct vfsmount , struct dentry *);
0226f492	116
294d71ff	117	extern int __legitimize_mnt(struct vfsmount *, unsigned);
48a066e7	118
c6609c0a IK	119	static inline bool __path_is_mountpoint(const struct path *path)
	120	{
	121	struct mount *m = __lookup_mnt(path->mnt, path->dentry);
	122	return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
	123	}
	124
80b5dce8 EB	125	extern void __detach_mounts(struct dentry *dentry);
	126
	127	static inline void detach_mounts(struct dentry *dentry)
	128	{
	129	if (!d_mountpoint(dentry))
	130	return;
	131	__detach_mounts(dentry);
	132	}
	133
0226f492 AV	134	static inline void get_mnt_ns(struct mnt_namespace *ns)
0226f492 AV	135	{
1a7b8969	136	refcount_inc(&ns->ns.count);
0226f492 AV	137	}
0226f492 AV	138
48a066e7	139	extern seqlock_t mount_lock;
719ea2fb	140
0226f492	141	struct proc_mounts {
0226f492 AV	142	struct mnt_namespace *ns;
	143	struct path root;
	144	int (show)(struct seq_file , struct vfsmount *);
	145	};
	146
	147	extern const struct seq_operations mounts_op;
7af1364f EB	148
	149	extern bool __is_local_mountpoint(struct dentry *dentry);
	150	static inline bool is_local_mountpoint(struct dentry *dentry)
	151	{
	152	if (!d_mountpoint(dentry))
	153	return false;
	154
	155	return __is_local_mountpoint(dentry);
	156	}
74e83122 AV	157
	158	static inline bool is_anon_ns(struct mnt_namespace *ns)
	159	{
	160	return ns->seq == 0;
	161	}
9f6c61f9	162
344bac8f CB	163	static inline bool mnt_ns_attached(const struct mount *mnt)
	164	{
	165	return !RB_EMPTY_NODE(&mnt->mnt_node);
	166	}
	167
2f576220 CB	168	static inline bool mnt_ns_empty(const struct mnt_namespace *ns)
	169	{
	170	return RB_EMPTY_ROOT(&ns->mounts);
	171	}
	172
2eea9ce4 MS	173	static inline void move_from_ns(struct mount mnt, struct list_head dt_list)
2eea9ce4 MS	174	{
2ce23285	175	struct mnt_namespace *ns = mnt->mnt_ns;
344bac8f	176	WARN_ON(!mnt_ns_attached(mnt));
2ce23285 CB	177	if (ns->mnt_last_node == &mnt->mnt_node)
	178	ns->mnt_last_node = rb_prev(&mnt->mnt_node);
	179	if (ns->mnt_first_node == &mnt->mnt_node)
	180	ns->mnt_first_node = rb_next(&mnt->mnt_node);
	181	rb_erase(&mnt->mnt_node, &ns->mounts);
344bac8f	182	RB_CLEAR_NODE(&mnt->mnt_node);
2eea9ce4 MS	183	list_add_tail(&mnt->mnt_list, dt_list);
	184	}
	185
620c266f	186	bool has_locked_children(struct mount mnt, struct dentry dentry);
4368898b CB	187	struct mnt_namespace get_sequential_mnt_ns(struct mnt_namespace mnt_ns,
	188	bool previous);
	189
a1d220d9 CB	190	static inline struct mnt_namespace to_mnt_ns(struct ns_common ns)
	191	{
	192	return container_of(ns, struct mnt_namespace, ns);
	193	}
0f46d81f	194
bf630c40 MS	195	#ifdef CONFIG_FSNOTIFY
	196	static inline void mnt_notify_add(struct mount *m)
	197	{
	198	/* Optimize the case where there are no watches */
	199	if ((m->mnt_ns && m->mnt_ns->n_fsnotify_marks) \|\|
	200	(m->prev_ns && m->prev_ns->n_fsnotify_marks))
	201	list_add_tail(&m->to_notify, &notify_list);
	202	else
	203	m->prev_ns = m->mnt_ns;
	204	}
	205	#else
	206	static inline void mnt_notify_add(struct mount *m)
	207	{
	208	}
	209	#endif
	210
0f46d81f	211	struct mnt_namespace mnt_ns_from_dentry(struct dentry dentry);