[PATCH 6/6] NFSD: Convert nfsd_export_shutdown() to sunrpc_cache_destroy_net()
STALE144d
From: Chuck Lever <cel@kernel.org>
Date: 2026-05-01 14:51:38
Also in:
linux-nfs, lkml
Subsystem:
filesystems (vfs and infrastructure), kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
From: Chuck Lever <redacted> The earlier conversion to the shared sunrpc cache workqueue left nfsd_export_shutdown() open-coding the unregister + drain + destroy sequence to amortize a single rcu_barrier()+flush across both caches. That micro-optimization runs only on namespace teardown and module unload, neither of which is performance-sensitive. Switch both caches to sunrpc_cache_destroy_net() so that the canonical teardown idiom is applied uniformly. A future change to the per-cache release callback that requires the cache_detail to remain valid through the drain remains correct without per-call-site auditing. With the last external caller of sunrpc_cache_drain() gone, drop the symbol export and the public declaration, and mark the function static so the compiler can inline it into sunrpc_cache_destroy_net(). Assisted-by: Claude:claude-opus-4-7[1m] Signed-off-by: Chuck Lever <redacted> --- fs/nfsd/export.c | 8 ++------ include/linux/sunrpc/cache.h | 1 - net/sunrpc/cache.c | 7 ++----- 3 files changed, 4 insertions(+), 12 deletions(-)
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 3c4340e743fa..c19f8e8c4f9e 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c@@ -2250,12 +2250,8 @@ nfsd_export_shutdown(struct net *net) dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum); - cache_unregister_net(nn->svc_expkey_cache, net); - cache_unregister_net(nn->svc_export_cache, net); - /* One drain covers both caches' deferred release work. */ - sunrpc_cache_drain(); - cache_destroy_net(nn->svc_expkey_cache, net); - cache_destroy_net(nn->svc_export_cache, net); + sunrpc_cache_destroy_net(nn->svc_expkey_cache, net); + sunrpc_cache_destroy_net(nn->svc_export_cache, net); svcauth_unix_purge(net); dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 84802438a5fc..22c18eeb5a97 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h@@ -238,7 +238,6 @@ extern void cache_flush(void); extern void cache_purge(struct cache_detail *detail); #define NEVER (0x7FFFFFFF) extern void sunrpc_cache_queue_release(struct rcu_work *rwork); -extern void sunrpc_cache_drain(void); extern int cache_register_net(struct cache_detail *cd, struct net *net); extern void cache_unregister_net(struct cache_detail *cd, struct net *net);
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index be7a0c8c416e..62ce334104d9 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c@@ -1737,18 +1737,15 @@ void sunrpc_cache_queue_release(struct rcu_work *rwork) } EXPORT_SYMBOL_GPL(sunrpc_cache_queue_release); -/** - * sunrpc_cache_drain - drain pending cache release work - * +/* * Wait for outstanding RCU callbacks to enqueue their release * work, then flush that work to completion. */ -void sunrpc_cache_drain(void) +static void sunrpc_cache_drain(void) { rcu_barrier(); flush_workqueue(sunrpc_cache_wq); } -EXPORT_SYMBOL_GPL(sunrpc_cache_drain); /** * sunrpc_cache_destroy_net - quiesce and tear down a per-net cache
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2.53.0