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authorKinglong Mee <kinglongmee@gmail.com>2017-02-08 09:54:33 +0800
committerJ. Bruce Fields <bfields@redhat.com>2017-02-08 16:49:32 -0500
commit471a930ad7d1b868456e835a67169a661ec73f65 (patch)
tree0b4cc18a4de82c303aceaa5ab72511acf21ebace /net/sunrpc/cache.c
parent81fa3275f95ac357188fe3ca81b8e7c75360c88d (diff)
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SUNRPC: Drop all entries from cache_detail when cache_purge()
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@gmail.com> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'net/sunrpc/cache.c')
-rw-r--r--net/sunrpc/cache.c41
1 files changed, 26 insertions, 15 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 502b9fe9817b..f5d6c60aae26 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);