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Commit 8d3b3591 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
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[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: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c0fef676

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