Commit 8d3b3591 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[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
...@@ -176,6 +176,7 @@ static inline void put_inotify_dev(struct inotify_device *dev) ...@@ -176,6 +176,7 @@ static inline void put_inotify_dev(struct inotify_device *dev)
if (atomic_dec_and_test(&dev->count)) { if (atomic_dec_and_test(&dev->count)) {
atomic_dec(&dev->user->inotify_devs); atomic_dec(&dev->user->inotify_devs);
free_uid(dev->user); free_uid(dev->user);
idr_destroy(&dev->idr);
kfree(dev); kfree(dev);
} }
} }
......
...@@ -75,4 +75,5 @@ int idr_pre_get(struct idr *idp, unsigned gfp_mask); ...@@ -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(struct idr *idp, void *ptr, int *id);
int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, 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_remove(struct idr *idp, int id);
void idr_destroy(struct idr *idp);
void idr_init(struct idr *idp); void idr_init(struct idr *idp);
...@@ -345,6 +345,19 @@ void idr_remove(struct idr *idp, int id) ...@@ -345,6 +345,19 @@ void idr_remove(struct idr *idp, int id)
} }
EXPORT_SYMBOL(idr_remove); 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 * idr_find - return pointer for given id
* @idp: idr handle * @idp: idr handle
......
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