[PATCH 21/32] SUNRPC: Ensure we initialise the cache_detail before creating procfs files

Trond Myklebust
2009-08-19T23:41:03Z

Also ensure that we destroy those files before we destroy the cache_detail.
Otherwise, user processes might attempt to write into uninitialised caches.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---
net/sunrpc/cache.c | 30 ++++++++++++++++++++----------
1 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 8ede4a6..062d4f4 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -347,13 +347,8 @@ static int create_cache_proc_entries(struct cache_detail *cd)
}
#endif

-int cache_register(struct cache_detail *cd)
+static void sunrpc_init_cache_detail(struct cache_detail *cd)
{
- int ret;
-
- ret = create_cache_proc_entries(cd);
- if (ret)
- return ret;
rwlock_init(&cd->hash_lock);
INIT_LIST_HEAD(&cd->queue);
spin_lock(&cache_list_lock);
@@ -367,11 +362,9 @@ int cache_register(struct cache_detail *cd)

/* start the cleaning process */
schedule_delayed_work(&cache_cleaner, 0);
- return 0;
}
-EXPORT_SYMBOL_GPL(cache_register);

-void cache_unregister(struct cache_detail *cd)
+static void sunrpc_destroy_cache_detail(struct cache_detail *cd)
{
cache_purge(cd);
spin_lock(&cache_list_lock);
@@ -386,7 +379,6 @@ void cache_unregister(struct cache_detail *cd)
list_del_init(&cd->others);
write_unlock(&cd->hash_lock);
spin_unlock(&cache_list_lock);
- remove_cache_proc_entries(cd);
if (list_empty(&cache_list)) {
/* module must be being unloaded so its safe to kill the worker */
cancel_delayed_work_sync(&cache_cleaner);
@@ -395,6 +387,24 @@ void cache_unregister(struct cache_detail *cd)
out:
printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name);
}
+
+int cache_register(struct cache_detail *cd)
+{
+ int ret;
+
+ sunrpc_init_cache_detail(cd);
+ ret = create_cache_proc_entries(cd);
+ if (ret)
+ sunrpc_destroy_cache_detail(cd);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cache_register);
+
+void cache_unregister(struct cache_detail *cd)
+{
+ remove_cache_proc_entries(cd);
+ sunrpc_destroy_cache_detail(cd);
+}
EXPORT_SYMBOL_GPL(cache_unregister);

/* clean cache tries to find something to clean
--
1.6.0.4