[PATCH] inotify/idr leak fix
Fix a bug which was reported and diagnosed by
Stefan Jones <stefan.jones@churchillrandoms.co.uk>
IDR trees include a cache of idr_layer objects. There's no way to destroy
this cache, so when we discard an overall idr tree we end up leaking some
memory.
Add and use idr_destroy() for this. v9fs and infiniband also need to use
idr_destroy() to avoid leaks.
Or, we make the cache global, like radix_tree_preload(). Which is probably
better. Later.
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Robert Love <rml@novell.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/inotify.c b/fs/inotify.c
index a37e9fb..9fbaebf 100644
--- a/fs/inotify.c
+++ b/fs/inotify.c
@@ -176,6 +176,7 @@
if (atomic_dec_and_test(&dev->count)) {
atomic_dec(&dev->user->inotify_devs);
free_uid(dev->user);
+ idr_destroy(&dev->idr);
kfree(dev);
}
}
diff --git a/include/linux/idr.h b/include/linux/idr.h
index ca3b7e4..3d5de45 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -75,4 +75,5 @@
int idr_get_new(struct idr *idp, void *ptr, int *id);
int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id);
void idr_remove(struct idr *idp, int id);
+void idr_destroy(struct idr *idp);
void idr_init(struct idr *idp);
diff --git a/lib/idr.c b/lib/idr.c
index 6415d05..d4df21d 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -346,6 +346,19 @@
EXPORT_SYMBOL(idr_remove);
/**
+ * idr_destroy - release all cached layers within an idr tree
+ * idp: idr handle
+ */
+void idr_destroy(struct idr *idp)
+{
+ while (idp->id_free_cnt) {
+ struct idr_layer *p = alloc_layer(idp);
+ kmem_cache_free(idr_layer_cache, p);
+ }
+}
+EXPORT_SYMBOL(idr_destroy);
+
+/**
* idr_find - return pointer for given id
* @idp: idr handle
* @id: lookup key