[PATCH v2 06/13] sunrpc: add helpers to count and snapshot pending cache requests
From: Jeff Layton <jlayton@kernel.org>
Date: 2026-03-25 14:41:01
Also in:
linux-nfs, lkml
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
Add sunrpc_cache_requests_count() and sunrpc_cache_requests_snapshot() to allow callers to count and snapshot the pending upcall request list without exposing struct cache_request outside of cache.c. Both functions skip entries that no longer have CACHE_PENDING set. The snapshot function takes a cache_get() reference on each item so the caller can safely use them after the queue_lock is released. These will be used by the nfsd generic netlink dumpit handler for svc_export upcall requests. Signed-off-by: Jeff Layton <jlayton@kernel.org> --- include/linux/sunrpc/cache.h | 6 +++++ net/sunrpc/cache.c | 61 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 67 insertions(+)
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index c358151c23950ab48e83991c6138bb7d0e049ace..f88dc6bb17c7078781b3cf7e0371f369eddcb563 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h@@ -251,6 +251,12 @@ extern int sunrpc_cache_register_pipefs(struct dentry *parent, const char *, extern void sunrpc_cache_unregister_pipefs(struct cache_detail *); extern void sunrpc_cache_unhash(struct cache_detail *, struct cache_head *); +int sunrpc_cache_requests_count(struct cache_detail *cd); +int sunrpc_cache_requests_snapshot(struct cache_detail *cd, + struct cache_head **items, + u64 *seqnos, int max, + u64 min_seqno); + /* Must store cache_detail in seq_file->private if using next three functions */ extern void *cache_seq_start_rcu(struct seq_file *file, loff_t *pos); extern void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos);
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index a182a179a1bfdb883ceda417a5809d967659be5d..1282c61030d35efd924072e2739109cfae3472e2 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c@@ -1899,3 +1899,64 @@ void sunrpc_cache_unhash(struct cache_detail *cd, struct cache_head *h) spin_unlock(&cd->hash_lock); } EXPORT_SYMBOL_GPL(sunrpc_cache_unhash); + +/** + * sunrpc_cache_requests_count - count pending upcall requests + * @cd: cache_detail to query + * + * Returns the number of requests on the cache's request list that + * still have CACHE_PENDING set. + */ +int sunrpc_cache_requests_count(struct cache_detail *cd) +{ + struct cache_request *crq; + int cnt = 0; + + spin_lock(&cd->queue_lock); + list_for_each_entry(crq, &cd->requests, list) { + if (test_bit(CACHE_PENDING, &crq->item->flags)) + cnt++; + } + spin_unlock(&cd->queue_lock); + return cnt; +} +EXPORT_SYMBOL_GPL(sunrpc_cache_requests_count); + +/** + * sunrpc_cache_requests_snapshot - snapshot pending upcall requests + * @cd: cache_detail to query + * @items: array to fill with cache_head pointers (caller-allocated) + * @seqnos: array to fill with sequence numbers (caller-allocated) + * @max: size of the arrays + * @min_seqno: only include entries with seqno > min_seqno (0 for all) + * + * Only entries with CACHE_PENDING set are included. Takes a reference + * on each cache_head via cache_get(). Caller must call cache_put() + * on each returned item when done. + * + * Returns the number of entries filled. + */ +int sunrpc_cache_requests_snapshot(struct cache_detail *cd, + struct cache_head **items, + u64 *seqnos, int max, + u64 min_seqno) +{ + struct cache_request *crq; + int i = 0; + + spin_lock(&cd->queue_lock); + list_for_each_entry(crq, &cd->requests, list) { + if (i >= max) + break; + if (!test_bit(CACHE_PENDING, &crq->item->flags)) + continue; + if (crq->seqno <= min_seqno) + continue; + items[i] = cache_get(crq->item); + seqnos[i] = crq->seqno; + i++; + } + spin_unlock(&cd->queue_lock); + return i; +} +EXPORT_SYMBOL_GPL(sunrpc_cache_requests_snapshot);
--
2.53.0