[linux.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>

struct mnt_namespace {
	atomic_t		count;
	struct ns_common	ns;
	struct mount *	root;
	struct list_head	list;
	struct user_namespace	*user_ns;
	struct ucounts		*ucounts;
	u64			seq;	/* Sequence number to prevent loops */
	wait_queue_head_t poll;
	u64 event;
	unsigned int		mounts; /* # of mounts in the namespace */
	unsigned int		pending_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 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;
#endif
	int mnt_id;			/* mount identifier */
	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);
extern bool 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)
{
	atomic_inc(&ns->count);
}

extern seqlock_t mount_lock;

static inline void lock_mount_hash(void)
{
	write_seqlock(&mount_lock);
}

static inline void unlock_mount_hash(void)
{
	write_sequnlock(&mount_lock);
}

struct proc_mounts {
	struct mnt_namespace *ns;
	struct path root;
	int (*show)(struct seq_file *, struct vfsmount *);
	void *cached_mount;
	u64 cached_event;
	loff_t cached_index;
};

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;
}
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 AV	7
	8	struct mnt_namespace {
	9	atomic_t count;
435d5f4b	10	struct ns_common ns;
be08d6d2	11	struct mount * root;
0226f492	12	struct list_head list;
771b1371	13	struct user_namespace *user_ns;
537f7ccb	14	struct ucounts *ucounts;
8823c079	15	u64 seq; /* Sequence number to prevent loops */
0226f492	16	wait_queue_head_t poll;
c7999c36	17	u64 event;
d2921684 EB	18	unsigned int mounts; /* # of mounts in the namespace */
d2921684 EB	19	unsigned int pending_mounts;
3859a271	20	} __randomize_layout;
b2dba1af	21
68e8a9fe AV	22	struct mnt_pcp {
	23	int mnt_count;
	24	int mnt_writers;
	25	};
	26
84d17192	27	struct mountpoint {
0818bf27	28	struct hlist_node m_hash;
84d17192	29	struct dentry *m_dentry;
0a5eb7c8	30	struct hlist_head m_list;
84d17192 AV	31	int m_count;
	32	};
	33
7d6fec45	34	struct mount {
38129a13	35	struct hlist_node mnt_hash;
0714a533	36	struct mount *mnt_parent;
a73324da	37	struct dentry *mnt_mountpoint;
7d6fec45	38	struct vfsmount mnt;
9ea459e1 AV	39	union {
	40	struct rcu_head mnt_rcu;
	41	struct llist_node mnt_llist;
	42	};
68e8a9fe AV	43	#ifdef CONFIG_SMP
68e8a9fe AV	44	struct mnt_pcp __percpu *mnt_pcp;
68e8a9fe AV	45	#else
	46	int mnt_count;
	47	int mnt_writers;
	48	#endif
6b41d536 AV	49	struct list_head mnt_mounts; /* list of children, anchored here */
6b41d536 AV	50	struct list_head mnt_child; /* and going through their mnt_child */
39f7c4db	51	struct list_head mnt_instance; /* mount instance on sb->s_mounts */
52ba1621	52	const char mnt_devname; / Name of device e.g. /dev/dsk/hda1 */
1a4eeaf2	53	struct list_head mnt_list;
6776db3d AV	54	struct list_head mnt_expire; /* link in fs-specific expiry list */
	55	struct list_head mnt_share; /* circular list of shared mounts */
	56	struct list_head mnt_slave_list;/* list of slave mounts */
	57	struct list_head mnt_slave; /* slave list entry */
32301920	58	struct mount mnt_master; / slave is on master->mnt_slave_list */
143c8c91	59	struct mnt_namespace mnt_ns; / containing namespace */
84d17192	60	struct mountpoint mnt_mp; / where is it mounted */
56cbb429 AV	61	union {
	62	struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
	63	struct hlist_node mnt_umount;
	64	};
99b19d16	65	struct list_head mnt_umounting; /* list entry for umount propagation */
c63181e6	66	#ifdef CONFIG_FSNOTIFY
08991e83	67	struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
c63181e6 AV	68	__u32 mnt_fsnotify_mask;
c63181e6 AV	69	#endif
15169fe7 AV	70	int mnt_id; /* mount identifier */
15169fe7 AV	71	int mnt_group_id; /* peer group identifier */
863d684f	72	int mnt_expiry_mark; /* true if marked for expiry */
215752fc	73	struct hlist_head mnt_pins;
56cbb429	74	struct hlist_head mnt_stuck_children;
3859a271	75	} __randomize_layout;
7d6fec45	76
f7a99c5b AV	77	#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
f7a99c5b AV	78
7d6fec45 AV	79	static inline struct mount real_mount(struct vfsmount mnt)
	80	{
	81	return container_of(mnt, struct mount, mnt);
	82	}
	83
676da58d	84	static inline int mnt_has_parent(struct mount *mnt)
b2dba1af	85	{
0714a533	86	return mnt != mnt->mnt_parent;
b2dba1af	87	}
c7105365	88
f7a99c5b AV	89	static inline int is_mounted(struct vfsmount *mnt)
	90	{
	91	/* neither detached nor internal? */
260a459d	92	return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
f7a99c5b AV	93	}
f7a99c5b AV	94
474279dc	95	extern struct mount __lookup_mnt(struct vfsmount , struct dentry *);
0226f492	96
294d71ff	97	extern int __legitimize_mnt(struct vfsmount *, unsigned);
48a066e7 AV	98	extern bool legitimize_mnt(struct vfsmount *, unsigned);
48a066e7 AV	99
c6609c0a IK	100	static inline bool __path_is_mountpoint(const struct path *path)
	101	{
	102	struct mount *m = __lookup_mnt(path->mnt, path->dentry);
	103	return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
	104	}
	105
80b5dce8 EB	106	extern void __detach_mounts(struct dentry *dentry);
	107
	108	static inline void detach_mounts(struct dentry *dentry)
	109	{
	110	if (!d_mountpoint(dentry))
	111	return;
	112	__detach_mounts(dentry);
	113	}
	114
0226f492 AV	115	static inline void get_mnt_ns(struct mnt_namespace *ns)
	116	{
	117	atomic_inc(&ns->count);
	118	}
	119
48a066e7	120	extern seqlock_t mount_lock;
719ea2fb AV	121
	122	static inline void lock_mount_hash(void)
	123	{
48a066e7	124	write_seqlock(&mount_lock);
719ea2fb AV	125	}
	126
	127	static inline void unlock_mount_hash(void)
	128	{
48a066e7	129	write_sequnlock(&mount_lock);
719ea2fb AV	130	}
719ea2fb AV	131
0226f492	132	struct proc_mounts {
0226f492 AV	133	struct mnt_namespace *ns;
	134	struct path root;
	135	int (show)(struct seq_file , struct vfsmount *);
c7999c36 AV	136	void *cached_mount;
	137	u64 cached_event;
	138	loff_t cached_index;
0226f492 AV	139	};
	140
	141	extern const struct seq_operations mounts_op;
7af1364f EB	142
	143	extern bool __is_local_mountpoint(struct dentry *dentry);
	144	static inline bool is_local_mountpoint(struct dentry *dentry)
	145	{
	146	if (!d_mountpoint(dentry))
	147	return false;
	148
	149	return __is_local_mountpoint(dentry);
	150	}
74e83122 AV	151
	152	static inline bool is_anon_ns(struct mnt_namespace *ns)
	153	{
	154	return ns->seq == 0;
	155	}