On Fri 24-01-14 08:26:45, Jiri Kosina wrote:
> On Fri, 24 Jan 2014, Jan Kara wrote:
>
> > Strange. I've installed systemd system (openSUSE 13.1) and it boots
> > with the latest Linus' kernel just fine (and I have at least FANOTIFY
> > and SLAB debugging set the same way as you). But it was only a KVM
> > guest. I'll try tomorrow with a physical machine I guess.
>
> FWIW the system I am reliably able to reproduce this on is opensuse 12.3
> with this systemd version:
>
> Version : 195
> Release : 13.18.1
Hum, still no luck with reproduction (either on physical machine or with
KVM). Anyway, I've looked at the code again and the previous patch had a
stupid bug (passing different pointer to fsnotify_destroy_event() than we
should have), plus also the merging function in fanotify was too
aggressive. Can you try the attached patch? It boots for me but that means
nothing since I cannot reproduce the issue... Thanks!
Honza
--
Jan Kara <j...@suse.cz>
SUSE Labs, CR
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 58772623f02a..1b3dd9de8518 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -18,7 +18,7 @@ static bool should_merge(struct fsnotify_event *old_fsn,
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
/* dont merge two permission events */
- if ((old_fsn->mask & FAN_ALL_PERM_EVENTS) &&
+ if ((old_fsn->mask & FAN_ALL_PERM_EVENTS) ||
(new_fsn->mask & FAN_ALL_PERM_EVENTS))
return false;
#endif
@@ -201,8 +201,10 @@ static int fanotify_handle_event(struct fsnotify_group *group,
}
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- if (fsn_event->mask & FAN_ALL_PERM_EVENTS)
+ if (fsn_event->mask & FAN_ALL_PERM_EVENTS) {
ret = fanotify_get_response_from_access(group, event);
+ fsnotify_destroy_event(group, fsn_event);
+ }
#endif
return ret;
}
@@ -221,7 +223,8 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event)
struct fanotify_event_info *event;
event = FANOTIFY_E(fsn_event);
- path_put(&event->path);
+ if (event->path.mnt)
+ path_put(&event->path);
put_pid(event->tgid);
kmem_cache_free(fanotify_event_cachep, event);
}
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 57d7c083cb4b..d493c72c71fd 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -319,7 +319,8 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
if (IS_ERR(kevent))
break;
ret = copy_event_to_user(group, kevent, buf);
- fsnotify_destroy_event(group, kevent);
+ if (!(kevent->mask & FAN_ALL_PERM_EVENTS))
+ fsnotify_destroy_event(group, kevent);
if (ret < 0)
break;
buf += ret;
