Add notifications for attaching and detaching mounts. The following new
event masks are added:
FAN_MNT_ATTACH - Mount was attached
FAN_MNT_DETACH - Mount was detached
If a mount is moved, then the event is reported with (FAN_MNT_ATTACH |
FAN_MNT_DETACH).
These events add an info record of type FAN_EVENT_INFO_TYPE_MNT containing
these fields identifying the affected mounts:
__u64 mnt_id - the ID of the mount (see statmount(2))
FAN_REPORT_MNT must be supplied to fanotify_init() to receive these events
and no other type of event can be received with this report type.
Marks are added with FAN_MARK_MNTNS, which records the mount namespace
belonging to the supplied path.
Prior to this patch mount namespace changes could be monitored by polling
/proc/self/mountinfo, which did not convey any information about what
changed.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
v3:
- use a global list protected for temporarily storing (Christian)
- move fsnotify_* calls to namespace_unlock() (Christian)
- downgrade namespace_sem to read for fsnotify_* calls (Christian)
- add notification for reparenting in propagate_umount (Christian)
- require nsfs file (/proc/PID/ns/mnt) in fanotify_mark(2) (Christian)
- cleaner check for fsnotify being initialized (Amir)
- fix stub __fsnotify_mntns_delete (kernel test robot)
- don't add FANOTIFY_MOUNT_EVENTS to FANOTIFY_FD_EVENTS (Amir)
v2:
- notify for whole namespace as this seems to be what people prefer
- move fsnotify() calls outside of mount_lock
- only report mnt_id, not parent_id
fs/mount.h | 21 ++++++++++
fs/namespace.c | 62 ++++++++++++++++++++++++++---
fs/notify/fanotify/fanotify.c | 37 +++++++++++++++--
fs/notify/fanotify/fanotify.h | 18 +++++++++
fs/notify/fanotify/fanotify_user.c | 64 ++++++++++++++++++++++++++++--
fs/notify/fdinfo.c | 2 +
fs/notify/fsnotify.c | 47 ++++++++++++++++++----
fs/notify/fsnotify.h | 11 +++++
fs/notify/mark.c | 14 +++++--
fs/pnode.c | 4 +-
include/linux/fanotify.h | 12 ++++--
include/linux/fsnotify.h | 20 ++++++++++
include/linux/fsnotify_backend.h | 40 ++++++++++++++++++-
include/linux/mnt_namespace.h | 1 +
include/uapi/linux/fanotify.h | 10 +++++
security/selinux/hooks.c | 4 ++
16 files changed, 340 insertions(+), 27 deletions(-)
diff --git a/fs/mount.h b/fs/mount.h
index 185fc56afc13..0ad68c90e7e2 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -5,6 +5,8 @@
#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;
@@ -14,6 +16,10 @@ struct mnt_namespace {
u64 seq; /* Sequence number to prevent loops */
wait_queue_head_t poll;
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 */
@@ -77,6 +83,9 @@ struct mount {
int mnt_expiry_mark; /* true if marked for expiry */
struct hlist_head mnt_pins;
struct hlist_head mnt_stuck_children;
+
+ struct list_head to_notify; /* need to queue notification */
+ struct mnt_namespace *prev_ns; /* previous namespace (NULL if none) */
} __randomize_layout;
#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
@@ -167,3 +176,15 @@ static inline struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
{
return container_of(ns, struct mnt_namespace, ns);
}
+
+static inline void add_notify(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;
+}
+
+struct mnt_namespace *mnt_ns_from_dentry(struct dentry *dentry);
diff --git a/fs/namespace.c b/fs/namespace.c
index 6eec7794f707..186f660abd60 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -79,6 +79,7 @@ static struct kmem_cache *mnt_cache __ro_after_init;
static DECLARE_RWSEM(namespace_sem);
static HLIST_HEAD(unmounted); /* protected by namespace_sem */
static LIST_HEAD(ex_mountpoints); /* protected by namespace_sem */
+LIST_HEAD(notify_list); /* protected by namespace_sem */
static DEFINE_RWLOCK(mnt_ns_tree_lock);
static struct rb_root mnt_ns_tree = RB_ROOT; /* protected by mnt_ns_tree_lock */
@@ -145,6 +146,7 @@ static void mnt_ns_release(struct mnt_namespace *ns)
/* keep alive for {list,stat}mount() */
if (refcount_dec_and_test(&ns->passive)) {
+ fsnotify_mntns_delete(ns);
put_user_ns(ns->user_ns);
kfree(ns);
}
@@ -1136,6 +1138,8 @@ static void mnt_add_to_ns(struct mnt_namespace *ns, struct mount *mnt)
rb_link_node(&mnt->mnt_node, parent, link);
rb_insert_color(&mnt->mnt_node, &ns->mounts);
mnt->mnt.mnt_flags |= MNT_ONRB;
+
+ add_notify(mnt);
}
/*
@@ -1683,17 +1687,53 @@ int may_umount(struct vfsmount *mnt)
EXPORT_SYMBOL(may_umount);
+static void notify_mount(struct mount *p)
+{
+ if (!p->prev_ns && p->mnt_ns) {
+ fsnotify_mnt_attach(p->mnt_ns, &p->mnt);
+ } else if (p->prev_ns && !p->mnt_ns) {
+ fsnotify_mnt_detach(p->prev_ns, &p->mnt);
+ } else if (p->prev_ns == p->mnt_ns) {
+ fsnotify_mnt_move(p->mnt_ns, &p->mnt);
+ } else {
+ fsnotify_mnt_detach(p->prev_ns, &p->mnt);
+ fsnotify_mnt_attach(p->mnt_ns, &p->mnt);
+ }
+ p->prev_ns = p->mnt_ns;
+}
+
static void namespace_unlock(void)
{
struct hlist_head head;
struct hlist_node *p;
- struct mount *m;
+ struct mount *m, *tmp;
LIST_HEAD(list);
+ bool notify = !list_empty(¬ify_list);
hlist_move_list(&unmounted, &head);
list_splice_init(&ex_mountpoints, &list);
- up_write(&namespace_sem);
+ /*
+ * No point blocking out concurrent readers while notifications are
+ * sent. This will also allow statmount()/listmount() to run
+ * concurrently.
+ */
+ if (unlikely(notify))
+ downgrade_write(&namespace_sem);
+
+ /*
+ * Notify about mounts that were added/reparented/remain connected after
+ * unmount.
+ */
+ list_for_each_entry_safe(m, tmp, ¬ify_list, to_notify) {
+ notify_mount(m);
+ list_del_init(&m->to_notify);
+ }
+
+ if (unlikely(notify))
+ up_read(&namespace_sem);
+ else
+ up_write(&namespace_sem);
shrink_dentry_list(&list);
@@ -1806,6 +1846,7 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
change_mnt_propagation(p, MS_PRIVATE);
if (disconnect)
hlist_add_head(&p->mnt_umount, &unmounted);
+ add_notify(p);
}
}
@@ -2103,16 +2144,24 @@ struct mnt_namespace *__lookup_next_mnt_ns(struct mnt_namespace *mntns, bool pre
}
}
+struct mnt_namespace *mnt_ns_from_dentry(struct dentry *dentry)
+{
+ if (!is_mnt_ns_file(dentry))
+ return NULL;
+
+ return to_mnt_ns(get_proc_ns(dentry->d_inode));
+}
+
static bool mnt_ns_loop(struct dentry *dentry)
{
/* Could bind mounting the mount namespace inode cause a
* mount namespace loop?
*/
- struct mnt_namespace *mnt_ns;
- if (!is_mnt_ns_file(dentry))
+ struct mnt_namespace *mnt_ns = mnt_ns_from_dentry(dentry);
+
+ if (!mnt_ns)
return false;
- mnt_ns = to_mnt_ns(get_proc_ns(dentry->d_inode));
return current->nsproxy->mnt_ns->seq >= mnt_ns->seq;
}
@@ -2505,6 +2554,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
dest_mp = smp;
unhash_mnt(source_mnt);
attach_mnt(source_mnt, top_mnt, dest_mp, beneath);
+ add_notify(source_mnt);
touch_mnt_namespace(source_mnt->mnt_ns);
} else {
if (source_mnt->mnt_ns) {
@@ -4420,6 +4470,8 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
list_del_init(&new_mnt->mnt_expire);
put_mountpoint(root_mp);
unlock_mount_hash();
+ add_notify(root_mnt);
+ add_notify(new_mnt);
chroot_fs_refs(&root, &new);
error = 0;
out4:
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 24c7c5df4998..a9dc004291bf 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -166,6 +166,8 @@ static bool fanotify_should_merge(struct fanotify_event *old,
case FANOTIFY_EVENT_TYPE_FS_ERROR:
return fanotify_error_event_equal(FANOTIFY_EE(old),
FANOTIFY_EE(new));
+ case FANOTIFY_EVENT_TYPE_MNT:
+ return false;
default:
WARN_ON_ONCE(1);
}
@@ -303,7 +305,11 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group,
pr_debug("%s: report_mask=%x mask=%x data=%p data_type=%d\n",
__func__, iter_info->report_mask, event_mask, data, data_type);
- if (!fid_mode) {
+ if (FAN_GROUP_FLAG(group, FAN_REPORT_MNT))
+ {
+ if (data_type != FSNOTIFY_EVENT_MNT)
+ return 0;
+ } else if (!fid_mode) {
/* Do we have path to open a file descriptor? */
if (!path)
return 0;
@@ -548,6 +554,20 @@ static struct fanotify_event *fanotify_alloc_path_event(const struct path *path,
return &pevent->fae;
}
+static struct fanotify_event *fanotify_alloc_mnt_event(u64 mnt_id, gfp_t gfp)
+{
+ struct fanotify_mnt_event *pevent;
+
+ pevent = kmem_cache_alloc(fanotify_mnt_event_cachep, gfp);
+ if (!pevent)
+ return NULL;
+
+ pevent->fae.type = FANOTIFY_EVENT_TYPE_MNT;
+ pevent->mnt_id = mnt_id;
+
+ return &pevent->fae;
+}
+
static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path,
gfp_t gfp)
{
@@ -715,6 +735,7 @@ static struct fanotify_event *fanotify_alloc_event(
fid_mode);
struct inode *dirid = fanotify_dfid_inode(mask, data, data_type, dir);
const struct path *path = fsnotify_data_path(data, data_type);
+ u64 mnt_id = fsnotify_data_mnt_id(data, data_type);
struct mem_cgroup *old_memcg;
struct dentry *moved = NULL;
struct inode *child = NULL;
@@ -810,8 +831,10 @@ static struct fanotify_event *fanotify_alloc_event(
moved, &hash, gfp);
} else if (fid_mode) {
event = fanotify_alloc_fid_event(id, fsid, &hash, gfp);
- } else {
+ } else if (path) {
event = fanotify_alloc_path_event(path, &hash, gfp);
+ } else /* if (mnt_id) */ {
+ event = fanotify_alloc_mnt_event(mnt_id, gfp);
}
if (!event)
@@ -910,7 +933,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
BUILD_BUG_ON(FAN_FS_ERROR != FS_ERROR);
BUILD_BUG_ON(FAN_RENAME != FS_RENAME);
- BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 21);
+ BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 23);
mask = fanotify_group_event_mask(group, iter_info, &match_mask,
mask, data, data_type, dir);
@@ -1011,6 +1034,11 @@ static void fanotify_free_error_event(struct fsnotify_group *group,
mempool_free(fee, &group->fanotify_data.error_events_pool);
}
+static void fanotify_free_mnt_event(struct fanotify_event *event)
+{
+ kmem_cache_free(fanotify_mnt_event_cachep, FANOTIFY_ME(event));
+}
+
static void fanotify_free_event(struct fsnotify_group *group,
struct fsnotify_event *fsn_event)
{
@@ -1037,6 +1065,9 @@ static void fanotify_free_event(struct fsnotify_group *group,
case FANOTIFY_EVENT_TYPE_FS_ERROR:
fanotify_free_error_event(group, event);
break;
+ case FANOTIFY_EVENT_TYPE_MNT:
+ fanotify_free_mnt_event(event);
+ break;
default:
WARN_ON_ONCE(1);
}
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index e5ab33cae6a7..f1a7cbedc9e3 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -9,6 +9,7 @@ extern struct kmem_cache *fanotify_mark_cache;
extern struct kmem_cache *fanotify_fid_event_cachep;
extern struct kmem_cache *fanotify_path_event_cachep;
extern struct kmem_cache *fanotify_perm_event_cachep;
+extern struct kmem_cache *fanotify_mnt_event_cachep;
/* Possible states of the permission event */
enum {
@@ -244,6 +245,7 @@ enum fanotify_event_type {
FANOTIFY_EVENT_TYPE_PATH_PERM,
FANOTIFY_EVENT_TYPE_OVERFLOW, /* struct fanotify_event */
FANOTIFY_EVENT_TYPE_FS_ERROR, /* struct fanotify_error_event */
+ FANOTIFY_EVENT_TYPE_MNT,
__FANOTIFY_EVENT_TYPE_NUM
};
@@ -409,12 +411,23 @@ struct fanotify_path_event {
struct path path;
};
+struct fanotify_mnt_event {
+ struct fanotify_event fae;
+ u64 mnt_id;
+};
+
static inline struct fanotify_path_event *
FANOTIFY_PE(struct fanotify_event *event)
{
return container_of(event, struct fanotify_path_event, fae);
}
+static inline struct fanotify_mnt_event *
+FANOTIFY_ME(struct fanotify_event *event)
+{
+ return container_of(event, struct fanotify_mnt_event, fae);
+}
+
/*
* Structure for permission fanotify events. It gets allocated and freed in
* fanotify_handle_event() since we wait there for user response. When the
@@ -456,6 +469,11 @@ static inline bool fanotify_is_error_event(u32 mask)
return mask & FAN_FS_ERROR;
}
+static inline bool fanotify_is_mnt_event(u32 mask)
+{
+ return mask & (FAN_MNT_ATTACH | FAN_MNT_DETACH);
+}
+
static inline const struct path *fanotify_event_path(struct fanotify_event *event)
{
if (event->type == FANOTIFY_EVENT_TYPE_PATH)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 2d85c71717d6..1e111730b6bf 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -19,6 +19,7 @@
#include <linux/memcontrol.h>
#include <linux/statfs.h>
#include <linux/exportfs.h>
+#include <linux/mnt_namespace.h>
#include <asm/ioctls.h>
@@ -114,6 +115,7 @@ struct kmem_cache *fanotify_mark_cache __ro_after_init;
struct kmem_cache *fanotify_fid_event_cachep __ro_after_init;
struct kmem_cache *fanotify_path_event_cachep __ro_after_init;
struct kmem_cache *fanotify_perm_event_cachep __ro_after_init;
+struct kmem_cache *fanotify_mnt_event_cachep __ro_after_init;
#define FANOTIFY_EVENT_ALIGN 4
#define FANOTIFY_FID_INFO_HDR_LEN \
@@ -122,6 +124,8 @@ struct kmem_cache *fanotify_perm_event_cachep __ro_after_init;
sizeof(struct fanotify_event_info_pidfd)
#define FANOTIFY_ERROR_INFO_LEN \
(sizeof(struct fanotify_event_info_error))
+#define FANOTIFY_MNT_INFO_LEN \
+ (sizeof(struct fanotify_event_info_mnt))
static int fanotify_fid_info_len(int fh_len, int name_len)
{
@@ -183,6 +187,8 @@ static size_t fanotify_event_len(unsigned int info_mode,
fh_len = fanotify_event_object_fh_len(event);
event_len += fanotify_fid_info_len(fh_len, dot_len);
}
+ if (fanotify_is_mnt_event(event->mask))
+ event_len += FANOTIFY_MNT_INFO_LEN;
return event_len;
}
@@ -380,6 +386,25 @@ static int process_access_response(struct fsnotify_group *group,
return -ENOENT;
}
+static size_t copy_mnt_info_to_user(struct fanotify_event *event,
+ char __user *buf, int count)
+{
+ struct fanotify_event_info_mnt info = { };
+
+ info.hdr.info_type = FAN_EVENT_INFO_TYPE_MNT;
+ info.hdr.len = FANOTIFY_MNT_INFO_LEN;
+
+ if (WARN_ON(count < info.hdr.len))
+ return -EFAULT;
+
+ info.mnt_id = FANOTIFY_ME(event)->mnt_id;
+
+ if (copy_to_user(buf, &info, sizeof(info)))
+ return -EFAULT;
+
+ return info.hdr.len;
+}
+
static size_t copy_error_info_to_user(struct fanotify_event *event,
char __user *buf, int count)
{
@@ -642,6 +667,14 @@ static int copy_info_records_to_user(struct fanotify_event *event,
total_bytes += ret;
}
+ if (fanotify_is_mnt_event(event->mask)) {
+ ret = copy_mnt_info_to_user(event, buf, count);
+ if (ret < 0)
+ return ret;
+ buf += ret;
+ count -= ret;
+ total_bytes += ret;
+ }
return total_bytes;
}
@@ -1449,6 +1482,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS)
return -EINVAL;
+ /* FIXME: check FAN_REPORT_MNT compatibility with other flags */
+
switch (event_f_flags & O_ACCMODE) {
case O_RDONLY:
case O_RDWR:
@@ -1718,6 +1753,9 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
case FAN_MARK_FILESYSTEM:
obj_type = FSNOTIFY_OBJ_TYPE_SB;
break;
+ case FAN_MARK_MNTNS:
+ obj_type = FSNOTIFY_OBJ_TYPE_MNTNS;
+ break;
default:
return -EINVAL;
}
@@ -1765,6 +1803,19 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
return -EINVAL;
group = fd_file(f)->private_data;
+ /* Only report mount events on mnt namespace */
+ if (FAN_GROUP_FLAG(group, FAN_REPORT_MNT)) {
+ if (mask & ~FANOTIFY_MOUNT_EVENTS)
+ return -EINVAL;
+ if (mark_type != FAN_MARK_MNTNS)
+ return -EINVAL;
+ } else {
+ if (mask & FANOTIFY_MOUNT_EVENTS)
+ return -EINVAL;
+ if (mark_type == FAN_MARK_MNTNS)
+ return -EINVAL;
+ }
+
/*
* An unprivileged user is not allowed to setup mount nor filesystem
* marks. This also includes setting up such marks by a group that
@@ -1802,7 +1853,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
* point.
*/
fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
- if (mask & ~(FANOTIFY_FD_EVENTS|FANOTIFY_EVENT_FLAGS) &&
+ if (mask & ~(FANOTIFY_FD_EVENTS|FANOTIFY_MOUNT_EVENTS|FANOTIFY_EVENT_FLAGS) &&
(!fid_mode || mark_type == FAN_MARK_MOUNT))
return -EINVAL;
@@ -1855,8 +1906,14 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
mnt = path.mnt;
if (mark_type == FAN_MARK_MOUNT)
obj = mnt;
- else
+ else if (mark_type == FAN_MARK_FILESYSTEM)
obj = mnt->mnt_sb;
+ else /* if (mark_type == FAN_MARK_MNTNS) */ {
+ obj = mnt_ns_from_dentry(path.dentry);
+ ret = -EINVAL;
+ if (!obj)
+ goto path_put_and_out;
+ }
}
/*
@@ -1952,7 +2009,7 @@ static int __init fanotify_user_setup(void)
FANOTIFY_DEFAULT_MAX_USER_MARKS);
BUILD_BUG_ON(FANOTIFY_INIT_FLAGS & FANOTIFY_INTERNAL_GROUP_FLAGS);
- BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 13);
+ BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 14);
BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 11);
fanotify_mark_cache = KMEM_CACHE(fanotify_mark,
@@ -1965,6 +2022,7 @@ static int __init fanotify_user_setup(void)
fanotify_perm_event_cachep =
KMEM_CACHE(fanotify_perm_event, SLAB_PANIC);
}
+ fanotify_mnt_event_cachep = KMEM_CACHE(fanotify_mnt_event, SLAB_PANIC);
fanotify_max_queued_events = FANOTIFY_DEFAULT_MAX_EVENTS;
init_user_ns.ucount_max[UCOUNT_FANOTIFY_GROUPS] =
diff --git a/fs/notify/fdinfo.c b/fs/notify/fdinfo.c
index dec553034027..505aabd62abb 100644
--- a/fs/notify/fdinfo.c
+++ b/fs/notify/fdinfo.c
@@ -123,6 +123,8 @@ static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
seq_printf(m, "fanotify sdev:%x mflags:%x mask:%x ignored_mask:%x\n",
sb->s_dev, mflags, mark->mask, mark->ignore_mask);
+ } else if (mark->connector->type == FSNOTIFY_OBJ_TYPE_MNTNS) {
+ /* FIXME: print info for mntns */
}
}
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index f976949d2634..2b2c3fd907c7 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -28,6 +28,11 @@ void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
fsnotify_clear_marks_by_mount(mnt);
}
+void __fsnotify_mntns_delete(struct mnt_namespace *mntns)
+{
+ fsnotify_clear_marks_by_mntns(mntns);
+}
+
/**
* fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
* @sb: superblock being unmounted.
@@ -402,7 +407,7 @@ static int send_to_group(__u32 mask, const void *data, int data_type,
file_name, cookie, iter_info);
}
-static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp)
+static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector *const *connp)
{
struct fsnotify_mark_connector *conn;
struct hlist_node *node = NULL;
@@ -520,14 +525,15 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
{
const struct path *path = fsnotify_data_path(data, data_type);
struct super_block *sb = fsnotify_data_sb(data, data_type);
- struct fsnotify_sb_info *sbinfo = fsnotify_sb_info(sb);
+ const struct fsnotify_mnt *mnt_data = fsnotify_data_mnt(data, data_type);
+ struct fsnotify_sb_info *sbinfo = sb ? fsnotify_sb_info(sb) : NULL;
struct fsnotify_iter_info iter_info = {};
struct mount *mnt = NULL;
struct inode *inode2 = NULL;
struct dentry *moved;
int inode2_type;
int ret = 0;
- __u32 test_mask, marks_mask;
+ __u32 test_mask, marks_mask = 0;
if (path)
mnt = real_mount(path->mnt);
@@ -560,17 +566,20 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
if ((!sbinfo || !sbinfo->sb_marks) &&
(!mnt || !mnt->mnt_fsnotify_marks) &&
(!inode || !inode->i_fsnotify_marks) &&
- (!inode2 || !inode2->i_fsnotify_marks))
+ (!inode2 || !inode2->i_fsnotify_marks) &&
+ (!mnt_data || !mnt_data->ns->n_fsnotify_marks))
return 0;
- marks_mask = READ_ONCE(sb->s_fsnotify_mask);
+ if (sb)
+ marks_mask |= READ_ONCE(sb->s_fsnotify_mask);
if (mnt)
marks_mask |= READ_ONCE(mnt->mnt_fsnotify_mask);
if (inode)
marks_mask |= READ_ONCE(inode->i_fsnotify_mask);
if (inode2)
marks_mask |= READ_ONCE(inode2->i_fsnotify_mask);
-
+ if (mnt_data)
+ marks_mask |= READ_ONCE(mnt_data->ns->n_fsnotify_mask);
/*
* If this is a modify event we may need to clear some ignore masks.
@@ -600,6 +609,10 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
iter_info.marks[inode2_type] =
fsnotify_first_mark(&inode2->i_fsnotify_marks);
}
+ if (mnt_data) {
+ iter_info.marks[FSNOTIFY_ITER_TYPE_MNTNS] =
+ fsnotify_first_mark(&mnt_data->ns->n_fsnotify_marks);
+ }
/*
* We need to merge inode/vfsmount/sb mark lists so that e.g. inode mark
@@ -623,11 +636,31 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
}
EXPORT_SYMBOL_GPL(fsnotify);
+void fsnotify_mnt(__u32 mask, struct mnt_namespace *ns, struct vfsmount *mnt)
+{
+ struct fsnotify_mnt data = {
+ .ns = ns,
+ .mnt_id = real_mount(mnt)->mnt_id_unique,
+ };
+
+ if (WARN_ON_ONCE(!ns))
+ return;
+
+ /*
+ * This is an optimization as well as making sure fsnotify_init() has
+ * been called.
+ */
+ if (!ns->n_fsnotify_marks)
+ return;
+
+ fsnotify(mask, &data, FSNOTIFY_EVENT_MNT, NULL, NULL, NULL, 0);
+}
+
static __init int fsnotify_init(void)
{
int ret;
- BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 23);
+ BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 25);
ret = init_srcu_struct(&fsnotify_mark_srcu);
if (ret)
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index 663759ed6fbc..5950c7a67f41 100644
--- a/fs/notify/fsnotify.h
+++ b/fs/notify/fsnotify.h
@@ -33,6 +33,12 @@ static inline struct super_block *fsnotify_conn_sb(
return conn->obj;
}
+static inline struct mnt_namespace *fsnotify_conn_mntns(
+ struct fsnotify_mark_connector *conn)
+{
+ return conn->obj;
+}
+
static inline struct super_block *fsnotify_object_sb(void *obj,
enum fsnotify_obj_type obj_type)
{
@@ -89,6 +95,11 @@ static inline void fsnotify_clear_marks_by_sb(struct super_block *sb)
fsnotify_destroy_marks(fsnotify_sb_marks(sb));
}
+static inline void fsnotify_clear_marks_by_mntns(struct mnt_namespace *mntns)
+{
+ fsnotify_destroy_marks(&mntns->n_fsnotify_marks);
+}
+
/*
* update the dentry->d_flags of all of inode's children to indicate if inode cares
* about events that happen to its children.
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 4981439e6209..798340db69d7 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -107,6 +107,8 @@ static fsnotify_connp_t *fsnotify_object_connp(void *obj,
return &real_mount(obj)->mnt_fsnotify_marks;
case FSNOTIFY_OBJ_TYPE_SB:
return fsnotify_sb_marks(obj);
+ case FSNOTIFY_OBJ_TYPE_MNTNS:
+ return &((struct mnt_namespace *)obj)->n_fsnotify_marks;
default:
return NULL;
}
@@ -120,6 +122,8 @@ static __u32 *fsnotify_conn_mask_p(struct fsnotify_mark_connector *conn)
return &fsnotify_conn_mount(conn)->mnt_fsnotify_mask;
else if (conn->type == FSNOTIFY_OBJ_TYPE_SB)
return &fsnotify_conn_sb(conn)->s_fsnotify_mask;
+ else if (conn->type == FSNOTIFY_OBJ_TYPE_MNTNS)
+ return &fsnotify_conn_mntns(conn)->n_fsnotify_mask;
return NULL;
}
@@ -346,12 +350,15 @@ static void *fsnotify_detach_connector_from_object(
fsnotify_conn_mount(conn)->mnt_fsnotify_mask = 0;
} else if (conn->type == FSNOTIFY_OBJ_TYPE_SB) {
fsnotify_conn_sb(conn)->s_fsnotify_mask = 0;
+ } else if (conn->type == FSNOTIFY_OBJ_TYPE_MNTNS) {
+ fsnotify_conn_mntns(conn)->n_fsnotify_mask = 0;
}
rcu_assign_pointer(*connp, NULL);
conn->obj = NULL;
conn->type = FSNOTIFY_OBJ_TYPE_DETACHED;
- fsnotify_update_sb_watchers(sb, conn);
+ if (sb)
+ fsnotify_update_sb_watchers(sb, conn);
return inode;
}
@@ -724,7 +731,7 @@ static int fsnotify_add_mark_list(struct fsnotify_mark *mark, void *obj,
* Attach the sb info before attaching a connector to any object on sb.
* The sb info will remain attached as long as sb lives.
*/
- if (!fsnotify_sb_info(sb)) {
+ if (sb && !fsnotify_sb_info(sb)) {
err = fsnotify_attach_info_to_sb(sb);
if (err)
return err;
@@ -770,7 +777,8 @@ static int fsnotify_add_mark_list(struct fsnotify_mark *mark, void *obj,
/* mark should be the last entry. last is the current last entry */
hlist_add_behind_rcu(&mark->obj_list, &last->obj_list);
added:
- fsnotify_update_sb_watchers(sb, conn);
+ if (sb)
+ fsnotify_update_sb_watchers(sb, conn);
/*
* Since connector is attached to object using cmpxchg() we are
* guaranteed that connector initialization is fully visible by anyone
diff --git a/fs/pnode.c b/fs/pnode.c
index a799e0315cc9..0c99de65724e 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -549,8 +549,10 @@ static void restore_mounts(struct list_head *to_restore)
mp = parent->mnt_mp;
parent = parent->mnt_parent;
}
- if (parent != mnt->mnt_parent)
+ if (parent != mnt->mnt_parent) {
mnt_change_mountpoint(parent, mp, mnt);
+ add_notify(mnt);
+ }
}
}
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index 89ff45bd6f01..d8699c165d94 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -25,7 +25,7 @@
#define FANOTIFY_FID_BITS (FAN_REPORT_DFID_NAME_TARGET)
-#define FANOTIFY_INFO_MODES (FANOTIFY_FID_BITS | FAN_REPORT_PIDFD)
+#define FANOTIFY_INFO_MODES (FANOTIFY_FID_BITS | FAN_REPORT_PIDFD | FAN_REPORT_MNT)
/*
* fanotify_init() flags that require CAP_SYS_ADMIN.
@@ -38,7 +38,8 @@
FAN_REPORT_PIDFD | \
FAN_REPORT_FD_ERROR | \
FAN_UNLIMITED_QUEUE | \
- FAN_UNLIMITED_MARKS)
+ FAN_UNLIMITED_MARKS | \
+ FAN_REPORT_MNT)
/*
* fanotify_init() flags that are allowed for user without CAP_SYS_ADMIN.
@@ -58,7 +59,7 @@
#define FANOTIFY_INTERNAL_GROUP_FLAGS (FANOTIFY_UNPRIV)
#define FANOTIFY_MARK_TYPE_BITS (FAN_MARK_INODE | FAN_MARK_MOUNT | \
- FAN_MARK_FILESYSTEM)
+ FAN_MARK_FILESYSTEM | FAN_MARK_MNTNS)
#define FANOTIFY_MARK_CMD_BITS (FAN_MARK_ADD | FAN_MARK_REMOVE | \
FAN_MARK_FLUSH)
@@ -99,10 +100,13 @@
/* Events that can only be reported with data type FSNOTIFY_EVENT_ERROR */
#define FANOTIFY_ERROR_EVENTS (FAN_FS_ERROR)
+#define FANOTIFY_MOUNT_EVENTS (FAN_MNT_ATTACH | FAN_MNT_DETACH)
+
/* Events that user can request to be notified on */
#define FANOTIFY_EVENTS (FANOTIFY_PATH_EVENTS | \
FANOTIFY_INODE_EVENTS | \
- FANOTIFY_ERROR_EVENTS)
+ FANOTIFY_ERROR_EVENTS | \
+ FANOTIFY_MOUNT_EVENTS )
/* Events that require a permission response from user */
#define FANOTIFY_PERM_EVENTS (FAN_OPEN_PERM | FAN_ACCESS_PERM | \
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 278620e063ab..ea998551dd0d 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -255,6 +255,11 @@ static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
__fsnotify_vfsmount_delete(mnt);
}
+static inline void fsnotify_mntns_delete(struct mnt_namespace *mntns)
+{
+ __fsnotify_mntns_delete(mntns);
+}
+
/*
* fsnotify_inoderemove - an inode is going away
*/
@@ -463,4 +468,19 @@ static inline int fsnotify_sb_error(struct super_block *sb, struct inode *inode,
NULL, NULL, NULL, 0);
}
+static inline void fsnotify_mnt_attach(struct mnt_namespace *ns, struct vfsmount *mnt)
+{
+ fsnotify_mnt(FS_MNT_ATTACH, ns, mnt);
+}
+
+static inline void fsnotify_mnt_detach(struct mnt_namespace *ns, struct vfsmount *mnt)
+{
+ fsnotify_mnt(FS_MNT_DETACH, ns, mnt);
+}
+
+static inline void fsnotify_mnt_move(struct mnt_namespace *ns, struct vfsmount *mnt)
+{
+ fsnotify_mnt(FS_MNT_MOVE, ns, mnt);
+}
+
#endif /* _LINUX_FS_NOTIFY_H */
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 3ecf7768e577..b84ac1ed9721 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -56,6 +56,10 @@
#define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */
#define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */
+#define FS_MNT_ATTACH 0x00100000 /* Mount was attached */
+#define FS_MNT_DETACH 0x00200000 /* Mount was detached */
+#define FS_MNT_MOVE (FS_MNT_ATTACH | FS_MNT_DETACH)
+
/*
* Set on inode mark that cares about things that happen to its children.
* Always set for dnotify and inotify.
@@ -102,7 +106,7 @@
FS_EVENTS_POSS_ON_CHILD | \
FS_DELETE_SELF | FS_MOVE_SELF | \
FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED | \
- FS_ERROR)
+ FS_ERROR | FS_MNT_ATTACH | FS_MNT_DETACH)
/* Extra flags that may be reported with event or control handling of events */
#define ALL_FSNOTIFY_FLAGS (FS_ISDIR | FS_EVENT_ON_CHILD | FS_DN_MULTISHOT)
@@ -288,6 +292,7 @@ enum fsnotify_data_type {
FSNOTIFY_EVENT_PATH,
FSNOTIFY_EVENT_INODE,
FSNOTIFY_EVENT_DENTRY,
+ FSNOTIFY_EVENT_MNT,
FSNOTIFY_EVENT_ERROR,
};
@@ -297,6 +302,11 @@ struct fs_error_report {
struct super_block *sb;
};
+struct fsnotify_mnt {
+ const struct mnt_namespace *ns;
+ u64 mnt_id;
+};
+
static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
{
switch (data_type) {
@@ -354,6 +364,24 @@ static inline struct super_block *fsnotify_data_sb(const void *data,
}
}
+static inline const struct fsnotify_mnt *fsnotify_data_mnt(const void *data,
+ int data_type)
+{
+ switch (data_type) {
+ case FSNOTIFY_EVENT_MNT:
+ return data;
+ default:
+ return NULL;
+ }
+}
+
+static inline u64 fsnotify_data_mnt_id(const void *data, int data_type)
+{
+ const struct fsnotify_mnt *mnt_data = fsnotify_data_mnt(data, data_type);
+
+ return mnt_data ? mnt_data->mnt_id : 0;
+}
+
static inline struct fs_error_report *fsnotify_data_error_report(
const void *data,
int data_type)
@@ -379,6 +407,7 @@ enum fsnotify_iter_type {
FSNOTIFY_ITER_TYPE_SB,
FSNOTIFY_ITER_TYPE_PARENT,
FSNOTIFY_ITER_TYPE_INODE2,
+ FSNOTIFY_ITER_TYPE_MNTNS,
FSNOTIFY_ITER_TYPE_COUNT
};
@@ -388,6 +417,7 @@ enum fsnotify_obj_type {
FSNOTIFY_OBJ_TYPE_INODE,
FSNOTIFY_OBJ_TYPE_VFSMOUNT,
FSNOTIFY_OBJ_TYPE_SB,
+ FSNOTIFY_OBJ_TYPE_MNTNS,
FSNOTIFY_OBJ_TYPE_COUNT,
FSNOTIFY_OBJ_TYPE_DETACHED = FSNOTIFY_OBJ_TYPE_COUNT
};
@@ -572,8 +602,10 @@ extern int __fsnotify_parent(struct dentry *dentry, __u32 mask, const void *data
extern void __fsnotify_inode_delete(struct inode *inode);
extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt);
extern void fsnotify_sb_delete(struct super_block *sb);
+extern void __fsnotify_mntns_delete(struct mnt_namespace *mntns);
extern void fsnotify_sb_free(struct super_block *sb);
extern u32 fsnotify_get_cookie(void);
+extern void fsnotify_mnt(__u32 mask, struct mnt_namespace *ns, struct vfsmount *mnt);
static inline __u32 fsnotify_parent_needed_mask(__u32 mask)
{
@@ -879,6 +911,9 @@ static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
static inline void fsnotify_sb_delete(struct super_block *sb)
{}
+static inline void __fsnotify_mntns_delete(struct mnt_namespace *mntns)
+{}
+
static inline void fsnotify_sb_free(struct super_block *sb)
{}
@@ -893,6 +928,9 @@ static inline u32 fsnotify_get_cookie(void)
static inline void fsnotify_unmount_inodes(struct super_block *sb)
{}
+static inline void fsnotify_mnt(__u32 mask, struct mnt_namespace *ns, struct vfsmount *mnt)
+{}
+
#endif /* CONFIG_FSNOTIFY */
#endif /* __KERNEL __ */
diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h
index 70b366b64816..05bc01c0f38a 100644
--- a/include/linux/mnt_namespace.h
+++ b/include/linux/mnt_namespace.h
@@ -10,6 +10,7 @@ struct mnt_namespace;
struct fs_struct;
struct user_namespace;
struct ns_common;
+struct vfsmount;
extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *,
struct user_namespace *, struct fs_struct *);
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 34f221d3a1b9..332ef8532390 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -25,6 +25,8 @@
#define FAN_OPEN_PERM 0x00010000 /* File open in perm check */
#define FAN_ACCESS_PERM 0x00020000 /* File accessed in perm check */
#define FAN_OPEN_EXEC_PERM 0x00040000 /* File open/exec in perm check */
+#define FAN_MNT_ATTACH 0x00100000 /* Mount was attached */
+#define FAN_MNT_DETACH 0x00200000 /* Mount was detached */
#define FAN_EVENT_ON_CHILD 0x08000000 /* Interested in child events */
@@ -61,6 +63,7 @@
#define FAN_REPORT_NAME 0x00000800 /* Report events with name */
#define FAN_REPORT_TARGET_FID 0x00001000 /* Report dirent target id */
#define FAN_REPORT_FD_ERROR 0x00002000 /* event->fd can report error */
+#define FAN_REPORT_MNT 0x00004000 /* Report mount events */
/* Convenience macro - FAN_REPORT_NAME requires FAN_REPORT_DIR_FID */
#define FAN_REPORT_DFID_NAME (FAN_REPORT_DIR_FID | FAN_REPORT_NAME)
@@ -91,6 +94,7 @@
#define FAN_MARK_INODE 0x00000000
#define FAN_MARK_MOUNT 0x00000010
#define FAN_MARK_FILESYSTEM 0x00000100
+#define FAN_MARK_MNTNS 0x00000110
/*
* Convenience macro - FAN_MARK_IGNORE requires FAN_MARK_IGNORED_SURV_MODIFY
@@ -143,6 +147,7 @@ struct fanotify_event_metadata {
#define FAN_EVENT_INFO_TYPE_DFID 3
#define FAN_EVENT_INFO_TYPE_PIDFD 4
#define FAN_EVENT_INFO_TYPE_ERROR 5
+#define FAN_EVENT_INFO_TYPE_MNT 6
/* Special info types for FAN_RENAME */
#define FAN_EVENT_INFO_TYPE_OLD_DFID_NAME 10
@@ -189,6 +194,11 @@ struct fanotify_event_info_error {
__u32 error_count;
};
+struct fanotify_event_info_mnt {
+ struct fanotify_event_info_header hdr;
+ __u64 mnt_id;
+};
+
/*
* User space may need to record additional information about its decision.
* The extra information type records what kind of information is included.
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 366c87a40bd1..aab8972a3124 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3395,6 +3395,10 @@ static int selinux_path_notify(const struct path *path, u64 mask,
case FSNOTIFY_OBJ_TYPE_INODE:
perm = FILE__WATCH;
break;
+ case FSNOTIFY_OBJ_TYPE_MNTNS:
+ /* FIXME: Is this correct??? */
+ perm = FILE__WATCH;
+ break;
default:
return -EINVAL;
}
--
2.47.0
