inotify: do not BUG on idr entries at inotify destruction
If an inotify watch is left in the idr when an fsnotify group is destroyed
this will lead to a BUG. This is not a dangerous situation and really
indicates a programming bug and leak of memory. This patch changes it to
use a WARN and a printk rather than killing people's boxes.
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index 5dcbafe..c9ee67b 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -105,16 +105,45 @@
return send;
}
+/*
+ * This is NEVER supposed to be called. Inotify marks should either have been
+ * removed from the idr when the watch was removed or in the
+ * fsnotify_destroy_mark_by_group() call when the inotify instance was being
+ * torn down. This is only called if the idr is about to be freed but there
+ * are still marks in it.
+ */
static int idr_callback(int id, void *p, void *data)
{
- BUG();
+ struct fsnotify_mark_entry *entry;
+ struct inotify_inode_mark_entry *ientry;
+ static bool warned = false;
+
+ if (warned)
+ return 0;
+
+ warned = false;
+ entry = p;
+ ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
+
+ WARN(1, "inotify closing but id=%d for entry=%p in group=%p still in "
+ "idr. Probably leaking memory\n", id, p, data);
+
+ /*
+ * I'm taking the liberty of assuming that the mark in question is a
+ * valid address and I'm dereferencing it. This might help to figure
+ * out why we got here and the panic is no worse than the original
+ * BUG() that was here.
+ */
+ if (entry)
+ printk(KERN_WARNING "entry->group=%p inode=%p wd=%d\n",
+ entry->group, entry->inode, ientry->wd);
return 0;
}
static void inotify_free_group_priv(struct fsnotify_group *group)
{
/* ideally the idr is empty and we won't hit the BUG in teh callback */
- idr_for_each(&group->inotify_data.idr, idr_callback, NULL);
+ idr_for_each(&group->inotify_data.idr, idr_callback, group);
idr_remove_all(&group->inotify_data.idr);
idr_destroy(&group->inotify_data.idr);
}