User always free the cache_detail after sunrpc_destroy_cache_detail(),
so, it must cleanup up entries that left in the cache_detail,
otherwise, NULL reference may be caused when using the left entries.
Also, NeriBrown suggests "write a stand-alone cache_purge()."
v3, move the cache_fresh_unlocked() out of write lock,
v2, a stand-alone cache_purge(), not only for sunrpc_destroy_cache_detail
Signed-off-by: Kinglong Mee <kinglongmee@xxxxxxxxx>
---
net/sunrpc/cache.c | 41 ++++++++++++++++++++++++++---------------
1 file changed, 26 insertions(+), 15 deletions(-)
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 8147e8d..f0a7390 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -362,11 +362,6 @@ void sunrpc_destroy_cache_detail(struct cache_detail *cd)
cache_purge(cd);
spin_lock(&cache_list_lock);
write_lock(&cd->hash_lock);
- if (cd->entries) {
- write_unlock(&cd->hash_lock);
- spin_unlock(&cache_list_lock);
- goto out;
- }
if (current_detail == cd)
current_detail = NULL;
list_del_init(&cd->others);
@@ -376,9 +371,6 @@ void sunrpc_destroy_cache_detail(struct cache_detail *cd)
/* module must be being unloaded so its safe to kill the worker */
cancel_delayed_work_sync(&cache_cleaner);
}
- return;
-out:
- printk(KERN_ERR "RPC: failed to unregister %s cache\n", cd->name);
}
EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);
@@ -497,13 +489,32 @@ EXPORT_SYMBOL_GPL(cache_flush);
void cache_purge(struct cache_detail *detail)
{
- time_t now = seconds_since_boot();
- if (detail->flush_time >= now)
- now = detail->flush_time + 1;
- /* 'now' is the maximum value any 'last_refresh' can have */
- detail->flush_time = now;
- detail->nextcheck = seconds_since_boot();
- cache_flush();
+ struct cache_head *ch = NULL;
+ struct hlist_head *head = NULL;
+ struct hlist_node *tmp = NULL;
+ int i = 0;
+
+ write_lock(&detail->hash_lock);
+ if (!detail->entries) {
+ write_unlock(&detail->hash_lock);
+ return;
+ }
+
+ dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name);
+ for (i = 0; i < detail->hash_size; i++) {
+ head = &detail->hash_table[i];
+ hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
+ hlist_del_init(&ch->cache_list);
+ detail->entries--;
+
+ set_bit(CACHE_CLEANED, &ch->flags);
+ write_unlock(&detail->hash_lock);
+ cache_fresh_unlocked(ch, detail);
+ cache_put(ch, detail);
+ write_lock(&detail->hash_lock);
+ }
+ }
+ write_unlock(&detail->hash_lock);
}
EXPORT_SYMBOL_GPL(cache_purge);
--
2.9.3
--
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