[PATCH] inotify/idr leak fix (8d3b3591) · Commits · 戴 / test

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>

fs/inotify.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -176,6 +176,7 @@ static inline void put_inotify_dev(struct inotify_device *dev)
		if (atomic_dec_and_test(&dev->count)) {
		atomic_dec(&dev->user->inotify_devs);
		free_uid(dev->user);
		idr_destroy(&dev->idr);
		kfree(dev);
		}
		}

include/linux/idr.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -75,4 +75,5 @@ int idr_pre_get(struct idr *idp, unsigned gfp_mask);
		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);

lib/idr.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -345,6 +345,19 @@ void idr_remove(struct idr *idp, int id)
		}
		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

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