Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279/* 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 file_system_type nullfs_fs_type;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; wait_queue_head_t poll; 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 struct hlist_head mnt_visible_mounts; /* SB_I_USERNS_VISIBLE mounts */ unsigned int nr_mounts; /* # of mounts in the namespace */ unsigned int pending_mounts; refcount_t passive; /* number references not pinning @mounts */ bool is_anon;} __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;};
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 mount *mnt_next_for_sb; /* the next two fields are hlist_node, */ struct mount * __aligned(1) *mnt_pprev_for_sb; /* except that LSB of pprev is stolen */#define WRITE_HOLD 1 /* ... for use by mnt_hold_writers() */ 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 hlist_head mnt_slave_list;/* list of slave mounts */ struct hlist_node mnt_slave; /* slave list entry */ struct mount *mnt_master; /* slave is on master->mnt_slave_list */ /* * Containing namespace (active or deactivating, non-refcounted). * Normally protected by namespace_sem. * Can also be accessed locklessly under RCU. RCU readers can't rely on * the namespace still being active, but implicitly hold a passive * reference (because an RCU delay happens between a namespace being * deactivated and the corresponding passive refcount drop). */ struct mnt_namespace *mnt_ns; 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; };#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_t_flags; /* namespace_sem-protected flags */ 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; struct hlist_node mnt_ns_visible; /* link in ns->mnt_visible_mounts */ struct mount *overmount; /* mounted on ->mnt_root */} __randomize_layout;
enum { T_SHARED = 1, /* mount is shared */ T_UNBINDABLE = 2, /* mount is unbindable */ T_MARKED = 4, /* internal mark for propagate_... */ T_UMOUNT_CANDIDATE = 8, /* for propagate_umount */
/* * T_SHARED_MASK is the set of flags that should be cleared when a * mount becomes shared. Currently, this is only the flag that says a * mount cannot be bind mounted, since this is how we create a mount * that shares events with another mount. If you add a new T_* * flag, consider how it interacts with shared mounts. */ T_SHARED_MASK = T_UNBINDABLE,};
#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(const 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){ ns_ref_inc(ns);}
extern seqlock_t mount_lock;
DEFINE_LOCK_GUARD_0(mount_writer, write_seqlock(&mount_lock), write_sequnlock(&mount_lock))DEFINE_LOCK_GUARD_0(mount_locked_reader, read_seqlock_excl(&mount_lock), read_sequnlock_excl(&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(const struct dentry *dentry);static inline bool is_local_mountpoint(const 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->is_anon;}
static inline bool anon_ns_root(const struct mount *m){ struct mnt_namespace *ns = READ_ONCE(m->mnt_ns);
return !IS_ERR_OR_NULL(ns) && is_anon_ns(ns) && m == ns->root;}
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 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); if (!hlist_unhashed(&mnt->mnt_ns_visible)) hlist_del_init(&mnt->mnt_ns_visible);}
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_FSNOTIFYstatic 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, ¬ify_list); else m->prev_ns = m->mnt_ns;}#elsestatic inline void mnt_notify_add(struct mount *m){}#endif
static inline struct mount *topmost_overmount(struct mount *m){ while (m->overmount) m = m->overmount; return m;}
static inline bool __test_write_hold(struct mount * __aligned(1) *val){ return (unsigned long)val & WRITE_HOLD;}
static inline bool test_write_hold(const struct mount *m){ return __test_write_hold(m->mnt_pprev_for_sb);}
static inline void set_write_hold(struct mount *m){ m->mnt_pprev_for_sb = (void *)((unsigned long)m->mnt_pprev_for_sb | WRITE_HOLD);}
static inline void clear_write_hold(struct mount *m){ m->mnt_pprev_for_sb = (void *)((unsigned long)m->mnt_pprev_for_sb & ~WRITE_HOLD);}
struct mnt_namespace *mnt_ns_from_dentry(struct dentry *dentry);