Merge branch 'rxrpc-afs-miscellaneous-fixes'

David Howells says:

====================
rxrpc, afs: Miscellaneous fixes

Here are some miscellaneous fixes for rxrpc and afs:

 (1) In the rxperf test server, make it correctly receive and decode the
     terminal magic cookie.

 (2) In rxrpc, get rid of the peer->mtu_lock as it is not only redundant,
     it now causes a lockdep complaint.

 (3) In rxrpc, fix a lockdep-detected instance where a spinlock is being
     bh-locked whilst irqs are disabled.

 (4) In afs, fix the ref of a server displaced from an afs_server_list
     struct.

 (5) In afs, make afs_server records belonging to a cell take refs on the
     afs_cell record so that the latter doesn't get deleted first when that
     cell is being destroyed.
====================

Link: https://patch.msgid.link/20250218192250.296870-1-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

8 files changed, 22 insertions, 16 deletions

diff --git a/fs/afs/server.c b/fs/afs/server.c
index 038f9d0ae3af..4504e16b458c 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -163,6 +163,8 @@ static struct afs_server *afs_install_server(struct afs_cell *cell,
 	rb_insert_color(&server->uuid_rb, &net->fs_servers);
 	hlist_add_head_rcu(&server->proc_link, &net->fs_proc);
 
+	afs_get_cell(cell, afs_cell_trace_get_server);
+
 added_dup:
 	write_seqlock(&net->fs_addr_lock);
 	estate = rcu_dereference_protected(server->endpoint_state,
@@ -442,6 +444,7 @@ static void afs_server_rcu(struct rcu_head *rcu)
 			 atomic_read(&server->active), afs_server_trace_free);
 	afs_put_endpoint_state(rcu_access_pointer(server->endpoint_state),
 			       afs_estate_trace_put_server);
+	afs_put_cell(server->cell, afs_cell_trace_put_server);
 	kfree(server);
 }
 
diff --git a/fs/afs/server_list.c b/fs/afs/server_list.c
index 7e7e567a7f8a..d20cd902ef94 100644
--- a/fs/afs/server_list.c
+++ b/fs/afs/server_list.c
@@ -97,8 +97,8 @@ struct afs_server_list *afs_alloc_server_list(struct afs_volume *volume,
 				break;
 		if (j < slist->nr_servers) {
 			if (slist->servers[j].server == server) {
-				afs_put_server(volume->cell->net, server,
-					       afs_server_trace_put_slist_isort);
+				afs_unuse_server(volume->cell->net, server,
+						 afs_server_trace_put_slist_isort);
 				continue;
 			}
 
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index b0db89058c91..958a2460330c 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -174,6 +174,7 @@ enum yfs_cm_operation {
 	EM(afs_cell_trace_get_queue_dns,	"GET q-dns ") \
 	EM(afs_cell_trace_get_queue_manage,	"GET q-mng ") \
 	EM(afs_cell_trace_get_queue_new,	"GET q-new ") \
+	EM(afs_cell_trace_get_server,		"GET server") \
 	EM(afs_cell_trace_get_vol,		"GET vol   ") \
 	EM(afs_cell_trace_insert,		"INSERT    ") \
 	EM(afs_cell_trace_manage,		"MANAGE    ") \
@@ -182,6 +183,7 @@ enum yfs_cm_operation {
 	EM(afs_cell_trace_put_destroy,		"PUT destry") \
 	EM(afs_cell_trace_put_queue_work,	"PUT q-work") \
 	EM(afs_cell_trace_put_queue_fail,	"PUT q-fail") \
+	EM(afs_cell_trace_put_server,		"PUT server") \
 	EM(afs_cell_trace_put_vol,		"PUT vol   ") \
 	EM(afs_cell_trace_see_source,		"SEE source") \
 	EM(afs_cell_trace_see_ws,		"SEE ws    ") \
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 5e740c486203..a64a0cab1bf7 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -360,7 +360,6 @@ struct rxrpc_peer {
 	u8			pmtud_jumbo;	/* Max jumbo packets for the MTU */
 	bool			ackr_adv_pmtud;	/* T if the peer advertises path-MTU */
 	unsigned int		ackr_max_data;	/* Maximum data advertised by peer */
-	seqcount_t		mtu_lock;	/* Lockless MTU access management */
 	unsigned int		if_mtu;		/* Local interface MTU (- hdrsize) for this peer */
 	unsigned int		max_data;	/* Maximum packet data capacity for this peer */
 	unsigned short		hdrsize;	/* header size (IP + UDP + RxRPC) */
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 9047ba13bd31..24aceb183c2c 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -810,9 +810,7 @@ static void rxrpc_input_ack_trailer(struct rxrpc_call *call, struct sk_buff *skb
 	if (max_mtu < peer->max_data) {
 		trace_rxrpc_pmtud_reduce(peer, sp->hdr.serial, max_mtu,
 					 rxrpc_pmtud_reduce_ack);
-		write_seqcount_begin(&peer->mtu_lock);
 		peer->max_data = max_mtu;
-		write_seqcount_end(&peer->mtu_lock);
 	}
 
 	max_data = umin(max_mtu, peer->max_data);
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
index bc283da9ee40..7f4729234957 100644
--- a/net/rxrpc/peer_event.c
+++ b/net/rxrpc/peer_event.c
@@ -130,9 +130,7 @@ static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, unsigned int mtu)
 			peer->pmtud_bad = max_data + 1;
 
 		trace_rxrpc_pmtud_reduce(peer, 0, max_data, rxrpc_pmtud_reduce_icmp);
-		write_seqcount_begin(&peer->mtu_lock);
 		peer->max_data = max_data;
-		write_seqcount_end(&peer->mtu_lock);
 	}
 }
 
@@ -408,13 +406,8 @@ void rxrpc_input_probe_for_pmtud(struct rxrpc_connection *conn, rxrpc_serial_t a
 	}
 
 	max_data = umin(max_data, peer->ackr_max_data);
-	if (max_data != peer->max_data) {
-		preempt_disable();
-		write_seqcount_begin(&peer->mtu_lock);
+	if (max_data != peer->max_data)
 		peer->max_data = max_data;
-		write_seqcount_end(&peer->mtu_lock);
-		preempt_enable();
-	}
 
 	jumbo = max_data + sizeof(struct rxrpc_jumbo_header);
 	jumbo /= RXRPC_JUMBO_SUBPKTLEN;
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
index 0fcc87f0409f..56e09d161a97 100644
--- a/net/rxrpc/peer_object.c
+++ b/net/rxrpc/peer_object.c
@@ -235,7 +235,6 @@ struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp,
 		peer->service_conns = RB_ROOT;
 		seqlock_init(&peer->service_conn_lock);
 		spin_lock_init(&peer->lock);
-		seqcount_init(&peer->mtu_lock);
 		peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
 		peer->recent_srtt_us = UINT_MAX;
 		peer->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
@@ -325,10 +324,10 @@ void rxrpc_new_incoming_peer(struct rxrpc_local *local, struct rxrpc_peer *peer)
 	hash_key = rxrpc_peer_hash_key(local, &peer->srx);
 	rxrpc_init_peer(local, peer, hash_key);
 
-	spin_lock_bh(&rxnet->peer_hash_lock);
+	spin_lock(&rxnet->peer_hash_lock);
 	hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
 	list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
-	spin_unlock_bh(&rxnet->peer_hash_lock);
+	spin_unlock(&rxnet->peer_hash_lock);
 }
 
 /*
diff --git a/net/rxrpc/rxperf.c b/net/rxrpc/rxperf.c
index 7ef93407be83..e848a4777b8c 100644
--- a/net/rxrpc/rxperf.c
+++ b/net/rxrpc/rxperf.c
@@ -478,6 +478,18 @@ static int rxperf_deliver_request(struct rxperf_call *call)
 		call->unmarshal++;
 		fallthrough;
 	case 2:
+		ret = rxperf_extract_data(call, true);
+		if (ret < 0)
+			return ret;
+
+		/* Deal with the terminal magic cookie. */
+		call->iov_len = 4;
+		call->kvec[0].iov_len	= call->iov_len;
+		call->kvec[0].iov_base	= call->tmp;
+		iov_iter_kvec(&call->iter, READ, call->kvec, 1, call->iov_len);
+		call->unmarshal++;
+		fallthrough;
+	case 3:
 		ret = rxperf_extract_data(call, false);
 		if (ret < 0)
 			return ret;