[LTP] Patch "NFSD: Refactor nfsd_reply_cache_free_locked()" has been added to the 6.1-stable tree

[gregkh@linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    NFSD: Refactor nfsd_reply_cache_free_locked()

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-refactor-nfsd_reply_cache_free_locked.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From stable+bounces-66324-greg=kroah.com@vger.kernel.org Sat Aug 10 22:00:43 2024
From: cel@kernel.org
Date: Sat, 10 Aug 2024 15:59:54 -0400
Subject: NFSD: Refactor nfsd_reply_cache_free_locked()
To: <stable@vger.kernel.org>
Cc: <linux-nfs@vger.kernel.org>, pvorel@suse.cz, sherry.yang@oracle.com, calum.mackay@oracle.com, kernel-team@fb.com, ltp@lists.linux.it, Chuck Lever <chuck.lever@oracle.com>, Jeff Layton <jlayton@kernel.org>
Message-ID: <20240810200009.9882-4-cel@kernel.org>

From: Chuck Lever <chuck.lever@oracle.com>

[ Upstream commit 35308e7f0fc3942edc87d9c6dc78c4a096428957 ]

To reduce contention on the bucket locks, we must avoid calling
kfree() while each bucket lock is held.

Start by refactoring nfsd_reply_cache_free_locked() into a helper
that removes an entry from the bucket (and must therefore run under
the lock) and a second helper that frees the entry (which does not
need to hold the lock).

For readability, rename the helpers nfsd_cacherep_<verb>.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Stable-dep-of: a9507f6af145 ("NFSD: Replace nfsd_prune_bucket()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/nfsd/nfscache.c |   27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -110,21 +110,33 @@ nfsd_reply_cache_alloc(struct svc_rqst *
 	return rp;
 }
 
+static void nfsd_cacherep_free(struct svc_cacherep *rp)
+{
+	if (rp->c_type == RC_REPLBUFF)
+		kfree(rp->c_replvec.iov_base);
+	kmem_cache_free(drc_slab, rp);
+}
+
 static void
-nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
-				struct nfsd_net *nn)
+nfsd_cacherep_unlink_locked(struct nfsd_net *nn, struct nfsd_drc_bucket *b,
+			    struct svc_cacherep *rp)
 {
-	if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) {
+	if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base)
 		nfsd_stats_drc_mem_usage_sub(nn, rp->c_replvec.iov_len);
-		kfree(rp->c_replvec.iov_base);
-	}
 	if (rp->c_state != RC_UNUSED) {
 		rb_erase(&rp->c_node, &b->rb_head);
 		list_del(&rp->c_lru);
 		atomic_dec(&nn->num_drc_entries);
 		nfsd_stats_drc_mem_usage_sub(nn, sizeof(*rp));
 	}
-	kmem_cache_free(drc_slab, rp);
+}
+
+static void
+nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
+				struct nfsd_net *nn)
+{
+	nfsd_cacherep_unlink_locked(nn, b, rp);
+	nfsd_cacherep_free(rp);
 }
 
 static void
@@ -132,8 +144,9 @@ nfsd_reply_cache_free(struct nfsd_drc_bu
 			struct nfsd_net *nn)
 {
 	spin_lock(&b->cache_lock);
-	nfsd_reply_cache_free_locked(b, rp, nn);
+	nfsd_cacherep_unlink_locked(nn, b, rp);
 	spin_unlock(&b->cache_lock);
+	nfsd_cacherep_free(rp);
 }
 
 int nfsd_drc_slab_create(void)


Patches currently in stable-queue which might be from kroah.com@vger.kernel.org are

queue-6.1/nfsd-remove-nfsd_stats-make-th_cnt-a-global-counter.patch
queue-6.1/nfsd-move-reply-cache-initialization-into-nfsd-startup.patch
queue-6.1/sunrpc-remove-pg_stats-from-svc_program.patch
queue-6.1/mptcp-pm-don-t-try-to-create-sf-if-alloc-failed.patch
queue-6.1/nfsd-rename-nfsd_reply_cache_alloc.patch
queue-6.1/nfsd-make-all-of-the-nfsd-stats-per-network-namespace.patch
queue-6.1/mptcp-pass-addr-to-mptcp_pm_alloc_anno_list.patch
queue-6.1/nfsd-move-init-of-percpu-reply_cache_stats-counters-back-to-nfsd_init_net.patch
queue-6.1/nfsd-replace-nfsd_prune_bucket.patch
queue-6.1/nfsd-stop-setting-pg_stats-for-unused-stats.patch
queue-6.1/sunrpc-don-t-change-sv_stats-if-it-doesn-t-exist.patch
queue-6.1/nfsd-make-svc_stat-per-network-namespace-instead-of-global.patch
queue-6.1/nfsd-fix-frame-size-warning-in-svc_export_parse.patch
queue-6.1/nfsd-rename-nfsd_net_-to-nfsd_stats_.patch
queue-6.1/mptcp-pm-do-not-ignore-subflow-if-signal-flag-is-also-set.patch
queue-6.1/nfsd-refactor-nfsd_reply_cache_free_locked.patch
queue-6.1/mptcp-fully-established-after-add_addr-echo-on-mpj.patch
queue-6.1/sunrpc-use-the-struct-net-as-the-svc-proc-private.patch
queue-6.1/selftests-mptcp-join-test-both-signal-subflow.patch
queue-6.1/sunrpc-pass-in-the-sv_stats-struct-through-svc_create_pooled.patch
queue-6.1/mptcp-pm-reduce-indentation-blocks.patch
queue-6.1/nfsd-rewrite-synopsis-of-nfsd_percpu_counters_init.patch
queue-6.1/nfsd-expose-proc-net-sunrpc-nfsd-in-net-namespaces.patch
queue-6.1/nfsd-refactor-the-duplicate-reply-cache-shrinker.patch