8 files changed, 158 insertions, 181 deletions

diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
index cba328315929..63a1ca4b9dee 100644
--- a/fs/notify/dnotify/dnotify.c
+++ b/fs/notify/dnotify/dnotify.c
@@ -319,7 +319,11 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
                 dn_mark = container_of(fsn_mark, struct dnotify_mark, fsn_mark);
                 spin_lock(&fsn_mark->lock);
         } else {
-                fsnotify_add_mark_locked(new_fsn_mark, inode, NULL, 0);
+                error = fsnotify_add_mark_locked(new_fsn_mark, inode, NULL, 0);
+                if (error) {
+                        mutex_unlock(&dnotify_group->mark_mutex);
+                        goto out_err;
+                }
                 spin_lock(&new_fsn_mark->lock);
                 fsn_mark = new_fsn_mark;
                 dn_mark = new_dn_mark;
@@ -345,6 +349,7 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
                  */
                 if (dn_mark == new_dn_mark)
                         destroy = 1;
+                error = 0;
                 goto out;
         }
 
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 09640b546363..54cf2d21b547 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -36,15 +36,13 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
 
         pr_debug("%s: list=%p event=%p\n", __func__, list, event);
 
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
         /*
          * Don't merge a permission event with any other event so that we know
          * the event structure we have created in fanotify_handle_event() is the
          * one we should check for permission response.
          */
-        if (event->mask & FAN_ALL_PERM_EVENTS)
+        if (fanotify_is_perm_event(event->mask))
                 return 0;
-#endif
 
         list_for_each_entry_reverse(test_event, list, list) {
                 if (should_merge(test_event, event)) {
@@ -56,7 +54,6 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
         return 0;
 }
 
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
 static int fanotify_get_response(struct fsnotify_group *group,
                                  struct fanotify_perm_event_info *event,
                                  struct fsnotify_iter_info *iter_info)
@@ -65,19 +62,8 @@ static int fanotify_get_response(struct fsnotify_group *group,
 
         pr_debug("%s: group=%p event=%p\n", __func__, group, event);
 
-        /*
-         * fsnotify_prepare_user_wait() fails if we race with mark deletion.
-         * Just let the operation pass in that case.
-         */
-        if (!fsnotify_prepare_user_wait(iter_info)) {
-                event->response = FAN_ALLOW;
-                goto out;
-        }
-
         wait_event(group->fanotify_data.access_waitq, event->response);
 
-        fsnotify_finish_user_wait(iter_info);
-out:
         /* userspace responded, convert to something usable */
         switch (event->response) {
         case FAN_ALLOW:
@@ -94,7 +80,6 @@ out:
         
         return ret;
 }
-#endif
 
 static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark,
                                        struct fsnotify_mark *vfsmnt_mark,
@@ -153,8 +138,7 @@ struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask,
 {
         struct fanotify_event_info *event;
 
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-        if (mask & FAN_ALL_PERM_EVENTS) {
+        if (fanotify_is_perm_event(mask)) {
                 struct fanotify_perm_event_info *pevent;
 
                 pevent = kmem_cache_alloc(fanotify_perm_event_cachep,
@@ -165,7 +149,6 @@ struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask,
                 pevent->response = 0;
                 goto init;
         }
-#endif
         event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL);
         if (!event)
                 return NULL;
@@ -212,9 +195,19 @@ static int fanotify_handle_event(struct fsnotify_group *group,
         pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode,
                  mask);
 
+        if (fanotify_is_perm_event(mask)) {
+                /*
+                 * fsnotify_prepare_user_wait() fails if we race with mark
+                 * deletion.  Just let the operation pass in that case.
+                 */
+                if (!fsnotify_prepare_user_wait(iter_info))
+                        return 0;
+        }
+
         event = fanotify_alloc_event(inode, mask, data);
+        ret = -ENOMEM;
         if (unlikely(!event))
-                return -ENOMEM;
+                goto finish;
 
         fsn_event = &event->fse;
         ret = fsnotify_add_event(group, fsn_event, fanotify_merge);
@@ -224,16 +217,16 @@ static int fanotify_handle_event(struct fsnotify_group *group,
                 /* Our event wasn't used in the end. Free it. */
                 fsnotify_destroy_event(group, fsn_event);
 
-                return 0;
-        }
-
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-        if (mask & FAN_ALL_PERM_EVENTS) {
+                ret = 0;
+        } else if (fanotify_is_perm_event(mask)) {
                 ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event),
                                             iter_info);
                 fsnotify_destroy_event(group, fsn_event);
         }
-#endif
+finish:
+        if (fanotify_is_perm_event(mask))
+                fsnotify_finish_user_wait(iter_info);
+
         return ret;
 }
 
@@ -253,13 +246,11 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event)
         event = FANOTIFY_E(fsn_event);
         path_put(&event->path);
         put_pid(event->tgid);
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-        if (fsn_event->mask & FAN_ALL_PERM_EVENTS) {
+        if (fanotify_is_perm_event(fsn_event->mask)) {
                 kmem_cache_free(fanotify_perm_event_cachep,
                                 FANOTIFY_PE(fsn_event));
                 return;
         }
-#endif
         kmem_cache_free(fanotify_event_cachep, event);
 }
 
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 7dacb7d80727..256d9d1ddea9 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -22,7 +22,6 @@ struct fanotify_event_info {
         struct pid *tgid;
 };
 
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
 /*
  * Structure for permission fanotify events. It gets allocated and freed in
  * fanotify_handle_event() since we wait there for user response. When the
@@ -41,7 +40,12 @@ FANOTIFY_PE(struct fsnotify_event *fse)
 {
         return container_of(fse, struct fanotify_perm_event_info, fae.fse);
 }
-#endif
+
+static inline bool fanotify_is_perm_event(u32 mask)
+{
+        return IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS) &&
+                mask & FAN_ALL_PERM_EVENTS;
+}
 
 static inline struct fanotify_event_info *FANOTIFY_E(struct fsnotify_event *fse)
 {
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 9752e7270e61..55499f5a1c96 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -143,7 +143,6 @@ static int fill_event_metadata(struct fsnotify_group *group,
         return ret;
 }
 
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
 static struct fanotify_perm_event_info *dequeue_event(
                                 struct fsnotify_group *group, int fd)
 {
@@ -200,7 +199,6 @@ static int process_access_response(struct fsnotify_group *group,
 
         return 0;
 }
-#endif
 
 static ssize_t copy_event_to_user(struct fsnotify_group *group,
                                   struct fsnotify_event *event,
@@ -222,10 +220,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
                          fanotify_event_metadata.event_len))
                 goto out_close_fd;
 
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-        if (event->mask & FAN_ALL_PERM_EVENTS)
+        if (fanotify_is_perm_event(event->mask))
                 FANOTIFY_PE(event)->fd = fd;
-#endif
 
         if (fd != FAN_NOFD)
                 fd_install(fd, f);
@@ -310,10 +306,9 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
                  * Permission events get queued to wait for response.  Other
                  * events can be destroyed now.
                  */
-                if (!(kevent->mask & FAN_ALL_PERM_EVENTS)) {
+                if (!fanotify_is_perm_event(kevent->mask)) {
                         fsnotify_destroy_event(group, kevent);
                 } else {
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
                         if (ret <= 0) {
                                 FANOTIFY_PE(kevent)->response = FAN_DENY;
                                 wake_up(&group->fanotify_data.access_waitq);
@@ -323,7 +318,6 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
                                         &group->fanotify_data.access_list);
                                 spin_unlock(&group->notification_lock);
                         }
-#endif
                 }
                 if (ret < 0)
                         break;
@@ -339,11 +333,13 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
 
 static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
 {
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
         struct fanotify_response response = { .fd = -1, .response = -1 };
         struct fsnotify_group *group;
         int ret;
 
+        if (!IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS))
+                return -EINVAL;
+
         group = file->private_data;
 
         if (count > sizeof(response))
@@ -359,16 +355,11 @@ static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t
                 count = ret;
 
         return count;
-#else
-        return -EINVAL;
-#endif
 }
 
 static int fanotify_release(struct inode *ignored, struct file *file)
 {
         struct fsnotify_group *group = file->private_data;
-
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
         struct fanotify_perm_event_info *event, *next;
         struct fsnotify_event *fsn_event;
 
@@ -404,14 +395,14 @@ static int fanotify_release(struct inode *ignored, struct file *file)
                         spin_unlock(&group->notification_lock);
                         fsnotify_destroy_event(group, fsn_event);
                         spin_lock(&group->notification_lock);
-                } else
+                } else {
                         FANOTIFY_PE(fsn_event)->response = FAN_ALLOW;
+                }
         }
         spin_unlock(&group->notification_lock);
 
         /* Response for all permission events it set, wakeup waiters */
         wake_up(&group->fanotify_data.access_waitq);
-#endif
 
         /* matches the fanotify_init->fsnotify_alloc_group */
         fsnotify_destroy_group(group);
@@ -769,10 +760,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
         if (force_o_largefile())
                 event_f_flags |= O_LARGEFILE;
         group->fanotify_data.f_flags = event_f_flags;
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
         init_waitqueue_head(&group->fanotify_data.access_waitq);
         INIT_LIST_HEAD(&group->fanotify_data.access_list);
-#endif
         switch (flags & FAN_ALL_CLASS_BITS) {
         case FAN_CLASS_NOTIF:
                 group->priority = FS_PRIO_0;
@@ -826,6 +815,7 @@ SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
         struct fsnotify_group *group;
         struct fd f;
         struct path path;
+        u32 valid_mask = FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD;
         int ret;
 
         pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n",
@@ -856,11 +846,10 @@ SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
                 mask &= ~FAN_ONDIR;
         }
 
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-        if (mask & ~(FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD))
-#else
-        if (mask & ~(FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD))
-#endif
+        if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS))
+                valid_mask |= FAN_ALL_PERM_EVENTS;
+
+        if (mask & ~valid_mask)
                 return -EINVAL;
 
         f = fdget(fanotify_fd);
@@ -950,10 +939,10 @@ static int __init fanotify_user_setup(void)
 {
         fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC);
         fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC);
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-        fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event_info,
-                                                SLAB_PANIC);
-#endif
+        if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS)) {
+                fanotify_perm_event_cachep =
+                        KMEM_CACHE(fanotify_perm_event_info, SLAB_PANIC);
+        }
 
         return 0;
 }
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 0c4583b61717..81d8959b6aef 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -243,6 +243,29 @@ static int send_to_group(struct inode *to_tell,
                                         file_name, cookie, iter_info);
 }
 
+static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp)
+{
+        struct fsnotify_mark_connector *conn;
+        struct hlist_node *node = NULL;
+
+        conn = srcu_dereference(*connp, &fsnotify_mark_srcu);
+        if (conn)
+                node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu);
+
+        return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
+}
+
+static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)
+{
+        struct hlist_node *node = NULL;
+
+        if (mark)
+                node = srcu_dereference(mark->obj_list.next,
+                                        &fsnotify_mark_srcu);
+
+        return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
+}
+
 /*
  * This is the main call to fsnotify.  The VFS calls into hook specific functions
  * in linux/fsnotify.h.  Those functions then in turn call here.  Here will call
@@ -252,11 +275,7 @@ static int send_to_group(struct inode *to_tell,
 int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
              const unsigned char *file_name, u32 cookie)
 {
-        struct hlist_node *inode_node = NULL, *vfsmount_node = NULL;
-        struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;
-        struct fsnotify_group *inode_group, *vfsmount_group;
-        struct fsnotify_mark_connector *inode_conn, *vfsmount_conn;
-        struct fsnotify_iter_info iter_info;
+        struct fsnotify_iter_info iter_info = {};
         struct mount *mnt;
         int ret = 0;
         /* global tests shouldn't care about events on child only the specific event */
@@ -291,26 +310,16 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
 
         if ((mask & FS_MODIFY) ||
             (test_mask & to_tell->i_fsnotify_mask)) {
-                inode_conn = srcu_dereference(to_tell->i_fsnotify_marks,
-                                              &fsnotify_mark_srcu);
-                if (inode_conn)
-                        inode_node = srcu_dereference(inode_conn->list.first,
-                                                      &fsnotify_mark_srcu);
+                iter_info.inode_mark =
+                        fsnotify_first_mark(&to_tell->i_fsnotify_marks);
         }
 
         if (mnt && ((mask & FS_MODIFY) ||
                     (test_mask & mnt->mnt_fsnotify_mask))) {
-                inode_conn = srcu_dereference(to_tell->i_fsnotify_marks,
-                                              &fsnotify_mark_srcu);
-                if (inode_conn)
-                        inode_node = srcu_dereference(inode_conn->list.first,
-                                                      &fsnotify_mark_srcu);
-                vfsmount_conn = srcu_dereference(mnt->mnt_fsnotify_marks,
-                                                 &fsnotify_mark_srcu);
-                if (vfsmount_conn)
-                        vfsmount_node = srcu_dereference(
-                                                vfsmount_conn->list.first,
-                                                &fsnotify_mark_srcu);
+                iter_info.inode_mark =
+                        fsnotify_first_mark(&to_tell->i_fsnotify_marks);
+                iter_info.vfsmount_mark =
+                        fsnotify_first_mark(&mnt->mnt_fsnotify_marks);
         }
 
         /*
@@ -318,39 +327,19 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
          * ignore masks are properly reflected for mount mark notifications.
          * That's why this traversal is so complicated...
          */
-        while (inode_node || vfsmount_node) {
-                inode_group = NULL;
-                inode_mark = NULL;
-                vfsmount_group = NULL;
-                vfsmount_mark = NULL;
-
-                if (inode_node) {
-                        inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
-                                                 struct fsnotify_mark, obj_list);
-                        inode_group = inode_mark->group;
-                }
-
-                if (vfsmount_node) {
-                        vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),
-                                                    struct fsnotify_mark, obj_list);
-                        vfsmount_group = vfsmount_mark->group;
-                }
-
-                if (inode_group && vfsmount_group) {
-                        int cmp = fsnotify_compare_groups(inode_group,
-                                                          vfsmount_group);
-                        if (cmp > 0) {
-                                inode_group = NULL;
+        while (iter_info.inode_mark || iter_info.vfsmount_mark) {
+                struct fsnotify_mark *inode_mark = iter_info.inode_mark;
+                struct fsnotify_mark *vfsmount_mark = iter_info.vfsmount_mark;
+
+                if (inode_mark && vfsmount_mark) {
+                        int cmp = fsnotify_compare_groups(inode_mark->group,
+                                                          vfsmount_mark->group);
+                        if (cmp > 0)
                                 inode_mark = NULL;
-                        } else if (cmp < 0) {
-                                vfsmount_group = NULL;
+                        else if (cmp < 0)
                                 vfsmount_mark = NULL;
-                        }
                 }
 
-                iter_info.inode_mark = inode_mark;
-                iter_info.vfsmount_mark = vfsmount_mark;
-
                 ret = send_to_group(to_tell, inode_mark, vfsmount_mark, mask,
                                     data, data_is, cookie, file_name,
                                     &iter_info);
@@ -358,12 +347,12 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
                 if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
                         goto out;
 
-                if (inode_group)
-                        inode_node = srcu_dereference(inode_node->next,
-                                                      &fsnotify_mark_srcu);
-                if (vfsmount_group)
-                        vfsmount_node = srcu_dereference(vfsmount_node->next,
-                                                         &fsnotify_mark_srcu);
+                if (inode_mark)
+                        iter_info.inode_mark =
+                                fsnotify_next_mark(iter_info.inode_mark);
+                if (vfsmount_mark)
+                        iter_info.vfsmount_mark =
+                                fsnotify_next_mark(iter_info.vfsmount_mark);
         }
         ret = 0;
 out:
diff --git a/fs/notify/group.c b/fs/notify/group.c
index 32357534de18..b7a4b6a69efa 100644
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -107,7 +107,7 @@ void fsnotify_destroy_group(struct fsnotify_group *group)
  */
 void fsnotify_get_group(struct fsnotify_group *group)
 {
-        atomic_inc(&group->refcnt);
+        refcount_inc(&group->refcnt);
 }
 
 /*
@@ -115,7 +115,7 @@ void fsnotify_get_group(struct fsnotify_group *group)
  */
 void fsnotify_put_group(struct fsnotify_group *group)
 {
-        if (atomic_dec_and_test(&group->refcnt))
+        if (refcount_dec_and_test(&group->refcnt))
                 fsnotify_final_destroy_group(group);
 }
 
@@ -131,7 +131,7 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
                 return ERR_PTR(-ENOMEM);
 
         /* set to 0 when there a no external references to this group */
-        atomic_set(&group->refcnt, 1);
+        refcount_set(&group->refcnt, 1);
         atomic_set(&group->num_marks, 0);
         atomic_set(&group->user_waits, 0);
 
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 7cc7d3fb1862..d3c20e0bb046 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -376,7 +376,7 @@ static struct inotify_inode_mark *inotify_idr_find_locked(struct fsnotify_group
 
                 fsnotify_get_mark(fsn_mark);
                 /* One ref for being in the idr, one ref we just took */
-                BUG_ON(atomic_read(&fsn_mark->refcnt) < 2);
+                BUG_ON(refcount_read(&fsn_mark->refcnt) < 2);
         }
 
         return i_mark;
@@ -446,7 +446,7 @@ static void inotify_remove_from_idr(struct fsnotify_group *group,
          * One ref for being in the idr
          * one ref grabbed by inotify_idr_find
          */
-        if (unlikely(atomic_read(&i_mark->fsn_mark.refcnt) < 2)) {
+        if (unlikely(refcount_read(&i_mark->fsn_mark.refcnt) < 2)) {
                 printk(KERN_ERR "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p\n",
                          __func__, i_mark, i_mark->wd, i_mark->fsn_mark.group);
                 /* we can't really recover with bad ref cnting.. */
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 9991f8826734..e9191b416434 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -105,18 +105,8 @@ static DECLARE_WORK(connector_reaper_work, fsnotify_connector_destroy_workfn);
 
 void fsnotify_get_mark(struct fsnotify_mark *mark)
 {
-        WARN_ON_ONCE(!atomic_read(&mark->refcnt));
-        atomic_inc(&mark->refcnt);
-}
-
-/*
- * Get mark reference when we found the mark via lockless traversal of object
- * list. Mark can be already removed from the list by now and on its way to be
- * destroyed once SRCU period ends.
- */
-static bool fsnotify_get_mark_safe(struct fsnotify_mark *mark)
-{
-        return atomic_inc_not_zero(&mark->refcnt);
+        WARN_ON_ONCE(!refcount_read(&mark->refcnt));
+        refcount_inc(&mark->refcnt);
 }
 
 static void __fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
@@ -211,7 +201,7 @@ void fsnotify_put_mark(struct fsnotify_mark *mark)
 
         /* Catch marks that were actually never attached to object */
         if (!mark->connector) {
-                if (atomic_dec_and_test(&mark->refcnt))
+                if (refcount_dec_and_test(&mark->refcnt))
                         fsnotify_final_mark_destroy(mark);
                 return;
         }
@@ -220,7 +210,7 @@ void fsnotify_put_mark(struct fsnotify_mark *mark)
          * We have to be careful so that traversals of obj_list under lock can
          * safely grab mark reference.
          */
-        if (!atomic_dec_and_lock(&mark->refcnt, &mark->connector->lock))
+        if (!refcount_dec_and_lock(&mark->refcnt, &mark->connector->lock))
                 return;
 
         conn = mark->connector;
@@ -256,32 +246,60 @@ void fsnotify_put_mark(struct fsnotify_mark *mark)
                            FSNOTIFY_REAPER_DELAY);
 }
 
-bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info)
+/*
+ * Get mark reference when we found the mark via lockless traversal of object
+ * list. Mark can be already removed from the list by now and on its way to be
+ * destroyed once SRCU period ends.
+ *
+ * Also pin the group so it doesn't disappear under us.
+ */
+static bool fsnotify_get_mark_safe(struct fsnotify_mark *mark)
 {
-        struct fsnotify_group *group;
-
-        if (WARN_ON_ONCE(!iter_info->inode_mark && !iter_info->vfsmount_mark))
-                return false;
-
-        if (iter_info->inode_mark)
-                group = iter_info->inode_mark->group;
-        else
-                group = iter_info->vfsmount_mark->group;
+        if (!mark)
+                return true;
+
+        if (refcount_inc_not_zero(&mark->refcnt)) {
+                spin_lock(&mark->lock);
+                if (mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED) {
+                        /* mark is attached, group is still alive then */
+                        atomic_inc(&mark->group->user_waits);
+                        spin_unlock(&mark->lock);
+                        return true;
+                }
+                spin_unlock(&mark->lock);
+                fsnotify_put_mark(mark);
+        }
+        return false;
+}
 
-        /*
-         * Since acquisition of mark reference is an atomic op as well, we can
-         * be sure this inc is seen before any effect of refcount increment.
-         */
-        atomic_inc(&group->user_waits);
+/*
+ * Puts marks and wakes up group destruction if necessary.
+ *
+ * Pairs with fsnotify_get_mark_safe()
+ */
+static void fsnotify_put_mark_wake(struct fsnotify_mark *mark)
+{
+        if (mark) {
+                struct fsnotify_group *group = mark->group;
 
-        if (iter_info->inode_mark) {
-                /* This can fail if mark is being removed */
-                if (!fsnotify_get_mark_safe(iter_info->inode_mark))
-                        goto out_wait;
+                fsnotify_put_mark(mark);
+                /*
+                 * We abuse notification_waitq on group shutdown for waiting for
+                 * all marks pinned when waiting for userspace.
+                 */
+                if (atomic_dec_and_test(&group->user_waits) && group->shutdown)
+                        wake_up(&group->notification_waitq);
         }
-        if (iter_info->vfsmount_mark) {
-                if (!fsnotify_get_mark_safe(iter_info->vfsmount_mark))
-                        goto out_inode;
+}
+
+bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info)
+{
+        /* This can fail if mark is being removed */
+        if (!fsnotify_get_mark_safe(iter_info->inode_mark))
+                return false;
+        if (!fsnotify_get_mark_safe(iter_info->vfsmount_mark)) {
+                fsnotify_put_mark_wake(iter_info->inode_mark);
+                return false;
         }
 
         /*
@@ -292,34 +310,13 @@ bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info)
         srcu_read_unlock(&fsnotify_mark_srcu, iter_info->srcu_idx);
 
         return true;
-out_inode:
-        if (iter_info->inode_mark)
-                fsnotify_put_mark(iter_info->inode_mark);
-out_wait:
-        if (atomic_dec_and_test(&group->user_waits) && group->shutdown)
-                wake_up(&group->notification_waitq);
-        return false;
 }
 
 void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info)
 {
-        struct fsnotify_group *group = NULL;
-
         iter_info->srcu_idx = srcu_read_lock(&fsnotify_mark_srcu);
-        if (iter_info->inode_mark) {
-                group = iter_info->inode_mark->group;
-                fsnotify_put_mark(iter_info->inode_mark);
-        }
-        if (iter_info->vfsmount_mark) {
-                group = iter_info->vfsmount_mark->group;
-                fsnotify_put_mark(iter_info->vfsmount_mark);
-        }
-        /*
-         * We abuse notification_waitq on group shutdown for waiting for all
-         * marks pinned when waiting for userspace.
-         */
-        if (atomic_dec_and_test(&group->user_waits) && group->shutdown)
-                wake_up(&group->notification_waitq);
+        fsnotify_put_mark_wake(iter_info->inode_mark);
+        fsnotify_put_mark_wake(iter_info->vfsmount_mark);
 }
 
 /*
@@ -338,7 +335,7 @@ void fsnotify_detach_mark(struct fsnotify_mark *mark)
 
         WARN_ON_ONCE(!mutex_is_locked(&group->mark_mutex));
         WARN_ON_ONCE(!srcu_read_lock_held(&fsnotify_mark_srcu) &&
-                     atomic_read(&mark->refcnt) < 1 +
+                     refcount_read(&mark->refcnt) < 1 +
                         !!(mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED));
 
         spin_lock(&mark->lock);
@@ -599,9 +596,11 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark, struct inode *inode,
 
         return ret;
 err:
+        spin_lock(&mark->lock);
         mark->flags &= ~(FSNOTIFY_MARK_FLAG_ALIVE |
                          FSNOTIFY_MARK_FLAG_ATTACHED);
         list_del_init(&mark->g_list);
+        spin_unlock(&mark->lock);
         atomic_dec(&group->num_marks);
 
         fsnotify_put_mark(mark);
@@ -738,7 +737,7 @@ void fsnotify_init_mark(struct fsnotify_mark *mark,
 {
         memset(mark, 0, sizeof(*mark));
         spin_lock_init(&mark->lock);
-        atomic_set(&mark->refcnt, 1);
+        refcount_set(&mark->refcnt, 1);
         fsnotify_get_group(group);
         mark->group = group;
 }