5.4-stable review patch. If anyone has any objections, please let me know.
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From: Long Li leo.lilong@huawei.com
[ Upstream commit 5ca00634c8bbb2979c73465588f486b9632f5ed5 ]
The cache_detail structure uses a "nextcheck" field to control hash table scanning intervals. When a table scan begins, nextcheck is set to current time plus 1800 seconds. During scanning, if cache_detail is not empty and a cache entry's expiry time is earlier than the current nextcheck, the nextcheck is updated to that expiry time.
This mechanism ensures that: 1) Empty cache_details are scanned every 1800 seconds to avoid unnecessary scans 2) Non-empty cache_details are scanned based on the earliest expiry time found
However, when adding a new cache entry to an empty cache_detail, the nextcheck time was not being updated, remaining at 1800 seconds. This could delay cache cleanup for up to 1800 seconds, potentially blocking threads(such as nfsd) that are waiting for cache cleanup.
Fix this by updating the nextcheck time whenever a new cache entry is added.
Signed-off-by: Long Li leo.lilong@huawei.com Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/sunrpc/cache.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 2215314dc4c5d..47623d49fa3a6 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -114,6 +114,8 @@ static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail,
hlist_add_head_rcu(&new->cache_list, head); detail->entries++; + if (detail->nextcheck > new->expiry_time) + detail->nextcheck = new->expiry_time + 1; cache_get(new); spin_unlock(&detail->hash_lock);