fanotify: move unrelated handling from copy_event_to_user()

Move code moving event structure to access_list from copy_event_to_user()
to fanotify_read() where it is more logical (so that we can immediately
see in the main loop that we either move the event to a different list
or free it).  Also move special error handling for permission events
from copy_event_to_user() to the main loop to have it in one place with
error handling for normal events.  This makes copy_event_to_user()
really only copy the event to user without any side effects.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 21 deletions

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index f1097f56137e..4e565c814309 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -199,7 +199,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
 
         ret = fill_event_metadata(group, &fanotify_event_metadata, event, &f);
         if (ret < 0)
-                goto out;
+                return ret;
 
         fd = fanotify_event_metadata.fd;
         ret = -EFAULT;
@@ -208,16 +208,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
                 goto out_close_fd;
 
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-        if (event->mask & FAN_ALL_PERM_EVENTS) {
-                struct fanotify_perm_event_info *pevent;
-
-                pevent = FANOTIFY_PE(event);
-                pevent->fd = fd;
-                spin_lock(&group->fanotify_data.access_lock);
-                list_add_tail(&pevent->fae.fse.list,
-                              &group->fanotify_data.access_list);
-                spin_unlock(&group->fanotify_data.access_lock);
-        }
+        if (event->mask & FAN_ALL_PERM_EVENTS)
+                FANOTIFY_PE(event)->fd = fd;
 #endif
 
         if (fd != FAN_NOFD)
@@ -229,13 +221,6 @@ out_close_fd:
                 put_unused_fd(fd);
                 fput(f);
         }
-out:
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
-        if (event->mask & FAN_ALL_PERM_EVENTS) {
-                FANOTIFY_PE(event)->response = FAN_DENY;
-                wake_up(&group->fanotify_data.access_waitq);
-        }
-#endif
         return ret;
 }
 
@@ -300,10 +285,23 @@ 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 (!(kevent->mask & FAN_ALL_PERM_EVENTS)) {
                         fsnotify_destroy_event(group, kevent);
-                if (ret < 0)
-                        break;
+                        if (ret < 0)
+                                break;
+                } else {
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+                        if (ret < 0) {
+                                FANOTIFY_PE(kevent)->response = FAN_DENY;
+                                wake_up(&group->fanotify_data.access_waitq);
+                                break;
+                        }
+                        spin_lock(&group->fanotify_data.access_lock);
+                        list_add_tail(&kevent->list,
+                                      &group->fanotify_data.access_list);
+                        spin_unlock(&group->fanotify_data.access_lock);
+#endif
+                }
                 buf += ret;
                 count -= ret;
         }