Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 734 insertions, 0 deletions

diff --git a/fs/dlm/member.c b/fs/dlm/member.c
new file mode 100644
index 000000000..923c01a8a
--- /dev/null
+++ b/fs/dlm/member.c
@@ -0,0 +1,734 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/******************************************************************************
+*******************************************************************************
+**
+**  Copyright (C) 2005-2011 Red Hat, Inc.  All rights reserved.
+**
+**
+*******************************************************************************
+******************************************************************************/
+
+#include "dlm_internal.h"
+#include "lockspace.h"
+#include "member.h"
+#include "recoverd.h"
+#include "recover.h"
+#include "rcom.h"
+#include "config.h"
+#include "midcomms.h"
+#include "lowcomms.h"
+
+int dlm_slots_version(struct dlm_header *h)
+{
+	if ((le32_to_cpu(h->h_version) & 0x0000FFFF) < DLM_HEADER_SLOTS)
+		return 0;
+	return 1;
+}
+
+void dlm_slot_save(struct dlm_ls *ls, struct dlm_rcom *rc,
+		   struct dlm_member *memb)
+{
+	struct rcom_config *rf = (struct rcom_config *)rc->rc_buf;
+
+	if (!dlm_slots_version(&rc->rc_header))
+		return;
+
+	memb->slot = le16_to_cpu(rf->rf_our_slot);
+	memb->generation = le32_to_cpu(rf->rf_generation);
+}
+
+void dlm_slots_copy_out(struct dlm_ls *ls, struct dlm_rcom *rc)
+{
+	struct dlm_slot *slot;
+	struct rcom_slot *ro;
+	int i;
+
+	ro = (struct rcom_slot *)(rc->rc_buf + sizeof(struct rcom_config));
+
+	/* ls_slots array is sparse, but not rcom_slots */
+
+	for (i = 0; i < ls->ls_slots_size; i++) {
+		slot = &ls->ls_slots[i];
+		if (!slot->nodeid)
+			continue;
+		ro->ro_nodeid = cpu_to_le32(slot->nodeid);
+		ro->ro_slot = cpu_to_le16(slot->slot);
+		ro++;
+	}
+}
+
+#define SLOT_DEBUG_LINE 128
+
+static void log_slots(struct dlm_ls *ls, uint32_t gen, int num_slots,
+		      struct rcom_slot *ro0, struct dlm_slot *array,
+		      int array_size)
+{
+	char line[SLOT_DEBUG_LINE];
+	int len = SLOT_DEBUG_LINE - 1;
+	int pos = 0;
+	int ret, i;
+
+	memset(line, 0, sizeof(line));
+
+	if (array) {
+		for (i = 0; i < array_size; i++) {
+			if (!array[i].nodeid)
+				continue;
+
+			ret = snprintf(line + pos, len - pos, " %d:%d",
+				       array[i].slot, array[i].nodeid);
+			if (ret >= len - pos)
+				break;
+			pos += ret;
+		}
+	} else if (ro0) {
+		for (i = 0; i < num_slots; i++) {
+			ret = snprintf(line + pos, len - pos, " %d:%d",
+				       ro0[i].ro_slot, ro0[i].ro_nodeid);
+			if (ret >= len - pos)
+				break;
+			pos += ret;
+		}
+	}
+
+	log_rinfo(ls, "generation %u slots %d%s", gen, num_slots, line);
+}
+
+int dlm_slots_copy_in(struct dlm_ls *ls)
+{
+	struct dlm_member *memb;
+	struct dlm_rcom *rc = ls->ls_recover_buf;
+	struct rcom_config *rf = (struct rcom_config *)rc->rc_buf;
+	struct rcom_slot *ro0, *ro;
+	int our_nodeid = dlm_our_nodeid();
+	int i, num_slots;
+	uint32_t gen;
+
+	if (!dlm_slots_version(&rc->rc_header))
+		return -1;
+
+	gen = le32_to_cpu(rf->rf_generation);
+	if (gen <= ls->ls_generation) {
+		log_error(ls, "dlm_slots_copy_in gen %u old %u",
+			  gen, ls->ls_generation);
+	}
+	ls->ls_generation = gen;
+
+	num_slots = le16_to_cpu(rf->rf_num_slots);
+	if (!num_slots)
+		return -1;
+
+	ro0 = (struct rcom_slot *)(rc->rc_buf + sizeof(struct rcom_config));
+
+	log_slots(ls, gen, num_slots, ro0, NULL, 0);
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		for (i = 0, ro = ro0; i < num_slots; i++, ro++) {
+			if (le32_to_cpu(ro->ro_nodeid) != memb->nodeid)
+				continue;
+			memb->slot = le16_to_cpu(ro->ro_slot);
+			memb->slot_prev = memb->slot;
+			break;
+		}
+
+		if (memb->nodeid == our_nodeid) {
+			if (ls->ls_slot && ls->ls_slot != memb->slot) {
+				log_error(ls, "dlm_slots_copy_in our slot "
+					  "changed %d %d", ls->ls_slot,
+					  memb->slot);
+				return -1;
+			}
+
+			if (!ls->ls_slot)
+				ls->ls_slot = memb->slot;
+		}
+
+		if (!memb->slot) {
+			log_error(ls, "dlm_slots_copy_in nodeid %d no slot",
+				   memb->nodeid);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/* for any nodes that do not support slots, we will not have set memb->slot
+   in wait_status_all(), so memb->slot will remain -1, and we will not
+   assign slots or set ls_num_slots here */
+
+int dlm_slots_assign(struct dlm_ls *ls, int *num_slots, int *slots_size,
+		     struct dlm_slot **slots_out, uint32_t *gen_out)
+{
+	struct dlm_member *memb;
+	struct dlm_slot *array;
+	int our_nodeid = dlm_our_nodeid();
+	int array_size, max_slots, i;
+	int need = 0;
+	int max = 0;
+	int num = 0;
+	uint32_t gen = 0;
+
+	/* our own memb struct will have slot -1 gen 0 */
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (memb->nodeid == our_nodeid) {
+			memb->slot = ls->ls_slot;
+			memb->generation = ls->ls_generation;
+			break;
+		}
+	}
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (memb->generation > gen)
+			gen = memb->generation;
+
+		/* node doesn't support slots */
+
+		if (memb->slot == -1)
+			return -1;
+
+		/* node needs a slot assigned */
+
+		if (!memb->slot)
+			need++;
+
+		/* node has a slot assigned */
+
+		num++;
+
+		if (!max || max < memb->slot)
+			max = memb->slot;
+
+		/* sanity check, once slot is assigned it shouldn't change */
+
+		if (memb->slot_prev && memb->slot && memb->slot_prev != memb->slot) {
+			log_error(ls, "nodeid %d slot changed %d %d",
+				  memb->nodeid, memb->slot_prev, memb->slot);
+			return -1;
+		}
+		memb->slot_prev = memb->slot;
+	}
+
+	array_size = max + need;
+	array = kcalloc(array_size, sizeof(*array), GFP_NOFS);
+	if (!array)
+		return -ENOMEM;
+
+	num = 0;
+
+	/* fill in slots (offsets) that are used */
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (!memb->slot)
+			continue;
+
+		if (memb->slot > array_size) {
+			log_error(ls, "invalid slot number %d", memb->slot);
+			kfree(array);
+			return -1;
+		}
+
+		array[memb->slot - 1].nodeid = memb->nodeid;
+		array[memb->slot - 1].slot = memb->slot;
+		num++;
+	}
+
+	/* assign new slots from unused offsets */
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (memb->slot)
+			continue;
+
+		for (i = 0; i < array_size; i++) {
+			if (array[i].nodeid)
+				continue;
+
+			memb->slot = i + 1;
+			memb->slot_prev = memb->slot;
+			array[i].nodeid = memb->nodeid;
+			array[i].slot = memb->slot;
+			num++;
+
+			if (!ls->ls_slot && memb->nodeid == our_nodeid)
+				ls->ls_slot = memb->slot;
+			break;
+		}
+
+		if (!memb->slot) {
+			log_error(ls, "no free slot found");
+			kfree(array);
+			return -1;
+		}
+	}
+
+	gen++;
+
+	log_slots(ls, gen, num, NULL, array, array_size);
+
+	max_slots = (DLM_MAX_APP_BUFSIZE - sizeof(struct dlm_rcom) -
+		     sizeof(struct rcom_config)) / sizeof(struct rcom_slot);
+
+	if (num > max_slots) {
+		log_error(ls, "num_slots %d exceeds max_slots %d",
+			  num, max_slots);
+		kfree(array);
+		return -1;
+	}
+
+	*gen_out = gen;
+	*slots_out = array;
+	*slots_size = array_size;
+	*num_slots = num;
+	return 0;
+}
+
+static void add_ordered_member(struct dlm_ls *ls, struct dlm_member *new)
+{
+	struct dlm_member *memb = NULL;
+	struct list_head *tmp;
+	struct list_head *newlist = &new->list;
+	struct list_head *head = &ls->ls_nodes;
+
+	list_for_each(tmp, head) {
+		memb = list_entry(tmp, struct dlm_member, list);
+		if (new->nodeid < memb->nodeid)
+			break;
+	}
+
+	if (!memb)
+		list_add_tail(newlist, head);
+	else {
+		/* FIXME: can use list macro here */
+		newlist->prev = tmp->prev;
+		newlist->next = tmp;
+		tmp->prev->next = newlist;
+		tmp->prev = newlist;
+	}
+}
+
+static int dlm_add_member(struct dlm_ls *ls, struct dlm_config_node *node)
+{
+	struct dlm_member *memb;
+	int error;
+
+	memb = kzalloc(sizeof(*memb), GFP_NOFS);
+	if (!memb)
+		return -ENOMEM;
+
+	error = dlm_lowcomms_connect_node(node->nodeid);
+	if (error < 0) {
+		kfree(memb);
+		return error;
+	}
+
+	memb->nodeid = node->nodeid;
+	memb->weight = node->weight;
+	memb->comm_seq = node->comm_seq;
+	dlm_midcomms_add_member(node->nodeid);
+	add_ordered_member(ls, memb);
+	ls->ls_num_nodes++;
+	return 0;
+}
+
+static struct dlm_member *find_memb(struct list_head *head, int nodeid)
+{
+	struct dlm_member *memb;
+
+	list_for_each_entry(memb, head, list) {
+		if (memb->nodeid == nodeid)
+			return memb;
+	}
+	return NULL;
+}
+
+int dlm_is_member(struct dlm_ls *ls, int nodeid)
+{
+	if (find_memb(&ls->ls_nodes, nodeid))
+		return 1;
+	return 0;
+}
+
+int dlm_is_removed(struct dlm_ls *ls, int nodeid)
+{
+	if (find_memb(&ls->ls_nodes_gone, nodeid))
+		return 1;
+	return 0;
+}
+
+static void clear_memb_list(struct list_head *head,
+			    void (*after_del)(int nodeid))
+{
+	struct dlm_member *memb;
+
+	while (!list_empty(head)) {
+		memb = list_entry(head->next, struct dlm_member, list);
+		list_del(&memb->list);
+		if (after_del)
+			after_del(memb->nodeid);
+		kfree(memb);
+	}
+}
+
+static void clear_members_cb(int nodeid)
+{
+	dlm_midcomms_remove_member(nodeid);
+}
+
+void dlm_clear_members(struct dlm_ls *ls)
+{
+	clear_memb_list(&ls->ls_nodes, clear_members_cb);
+	ls->ls_num_nodes = 0;
+}
+
+void dlm_clear_members_gone(struct dlm_ls *ls)
+{
+	clear_memb_list(&ls->ls_nodes_gone, NULL);
+}
+
+static void make_member_array(struct dlm_ls *ls)
+{
+	struct dlm_member *memb;
+	int i, w, x = 0, total = 0, all_zero = 0, *array;
+
+	kfree(ls->ls_node_array);
+	ls->ls_node_array = NULL;
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (memb->weight)
+			total += memb->weight;
+	}
+
+	/* all nodes revert to weight of 1 if all have weight 0 */
+
+	if (!total) {
+		total = ls->ls_num_nodes;
+		all_zero = 1;
+	}
+
+	ls->ls_total_weight = total;
+	array = kmalloc_array(total, sizeof(*array), GFP_NOFS);
+	if (!array)
+		return;
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (!all_zero && !memb->weight)
+			continue;
+
+		if (all_zero)
+			w = 1;
+		else
+			w = memb->weight;
+
+		DLM_ASSERT(x < total, printk("total %d x %d\n", total, x););
+
+		for (i = 0; i < w; i++)
+			array[x++] = memb->nodeid;
+	}
+
+	ls->ls_node_array = array;
+}
+
+/* send a status request to all members just to establish comms connections */
+
+static int ping_members(struct dlm_ls *ls)
+{
+	struct dlm_member *memb;
+	int error = 0;
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (dlm_recovery_stopped(ls)) {
+			error = -EINTR;
+			break;
+		}
+		error = dlm_rcom_status(ls, memb->nodeid, 0);
+		if (error)
+			break;
+	}
+	if (error)
+		log_rinfo(ls, "ping_members aborted %d last nodeid %d",
+			  error, ls->ls_recover_nodeid);
+	return error;
+}
+
+static void dlm_lsop_recover_prep(struct dlm_ls *ls)
+{
+	if (!ls->ls_ops || !ls->ls_ops->recover_prep)
+		return;
+	ls->ls_ops->recover_prep(ls->ls_ops_arg);
+}
+
+static void dlm_lsop_recover_slot(struct dlm_ls *ls, struct dlm_member *memb)
+{
+	struct dlm_slot slot;
+	uint32_t seq;
+	int error;
+
+	if (!ls->ls_ops || !ls->ls_ops->recover_slot)
+		return;
+
+	/* if there is no comms connection with this node
+	   or the present comms connection is newer
+	   than the one when this member was added, then
+	   we consider the node to have failed (versus
+	   being removed due to dlm_release_lockspace) */
+
+	error = dlm_comm_seq(memb->nodeid, &seq);
+
+	if (!error && seq == memb->comm_seq)
+		return;
+
+	slot.nodeid = memb->nodeid;
+	slot.slot = memb->slot;
+
+	ls->ls_ops->recover_slot(ls->ls_ops_arg, &slot);
+}
+
+void dlm_lsop_recover_done(struct dlm_ls *ls)
+{
+	struct dlm_member *memb;
+	struct dlm_slot *slots;
+	int i, num;
+
+	if (!ls->ls_ops || !ls->ls_ops->recover_done)
+		return;
+
+	num = ls->ls_num_nodes;
+	slots = kcalloc(num, sizeof(*slots), GFP_KERNEL);
+	if (!slots)
+		return;
+
+	i = 0;
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (i == num) {
+			log_error(ls, "dlm_lsop_recover_done bad num %d", num);
+			goto out;
+		}
+		slots[i].nodeid = memb->nodeid;
+		slots[i].slot = memb->slot;
+		i++;
+	}
+
+	ls->ls_ops->recover_done(ls->ls_ops_arg, slots, num,
+				 ls->ls_slot, ls->ls_generation);
+ out:
+	kfree(slots);
+}
+
+static struct dlm_config_node *find_config_node(struct dlm_recover *rv,
+						int nodeid)
+{
+	int i;
+
+	for (i = 0; i < rv->nodes_count; i++) {
+		if (rv->nodes[i].nodeid == nodeid)
+			return &rv->nodes[i];
+	}
+	return NULL;
+}
+
+int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
+{
+	struct dlm_member *memb, *safe;
+	struct dlm_config_node *node;
+	int i, error, neg = 0, low = -1;
+
+	/* previously removed members that we've not finished removing need to
+	 * count as a negative change so the "neg" recovery steps will happen
+	 *
+	 * This functionality must report all member changes to lsops or
+	 * midcomms layer and must never return before.
+	 */
+
+	list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
+		log_rinfo(ls, "prev removed member %d", memb->nodeid);
+		neg++;
+	}
+
+	/* move departed members from ls_nodes to ls_nodes_gone */
+
+	list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) {
+		node = find_config_node(rv, memb->nodeid);
+		if (node && !node->new)
+			continue;
+
+		if (!node) {
+			log_rinfo(ls, "remove member %d", memb->nodeid);
+		} else {
+			/* removed and re-added */
+			log_rinfo(ls, "remove member %d comm_seq %u %u",
+				  memb->nodeid, memb->comm_seq, node->comm_seq);
+		}
+
+		neg++;
+		list_move(&memb->list, &ls->ls_nodes_gone);
+		dlm_midcomms_remove_member(memb->nodeid);
+		ls->ls_num_nodes--;
+		dlm_lsop_recover_slot(ls, memb);
+	}
+
+	/* add new members to ls_nodes */
+
+	for (i = 0; i < rv->nodes_count; i++) {
+		node = &rv->nodes[i];
+		if (dlm_is_member(ls, node->nodeid))
+			continue;
+		error = dlm_add_member(ls, node);
+		if (error)
+			return error;
+
+		log_rinfo(ls, "add member %d", node->nodeid);
+	}
+
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (low == -1 || memb->nodeid < low)
+			low = memb->nodeid;
+	}
+	ls->ls_low_nodeid = low;
+
+	make_member_array(ls);
+	*neg_out = neg;
+
+	error = ping_members(ls);
+	log_rinfo(ls, "dlm_recover_members %d nodes", ls->ls_num_nodes);
+	return error;
+}
+
+/* Userspace guarantees that dlm_ls_stop() has completed on all nodes before
+   dlm_ls_start() is called on any of them to start the new recovery. */
+
+int dlm_ls_stop(struct dlm_ls *ls)
+{
+	int new;
+
+	/*
+	 * Prevent dlm_recv from being in the middle of something when we do
+	 * the stop.  This includes ensuring dlm_recv isn't processing a
+	 * recovery message (rcom), while dlm_recoverd is aborting and
+	 * resetting things from an in-progress recovery.  i.e. we want
+	 * dlm_recoverd to abort its recovery without worrying about dlm_recv
+	 * processing an rcom at the same time.  Stopping dlm_recv also makes
+	 * it easy for dlm_receive_message() to check locking stopped and add a
+	 * message to the requestqueue without races.
+	 */
+
+	down_write(&ls->ls_recv_active);
+
+	/*
+	 * Abort any recovery that's in progress (see RECOVER_STOP,
+	 * dlm_recovery_stopped()) and tell any other threads running in the
+	 * dlm to quit any processing (see RUNNING, dlm_locking_stopped()).
+	 */
+
+	spin_lock(&ls->ls_recover_lock);
+	set_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
+	new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags);
+	ls->ls_recover_seq++;
+	spin_unlock(&ls->ls_recover_lock);
+
+	/*
+	 * Let dlm_recv run again, now any normal messages will be saved on the
+	 * requestqueue for later.
+	 */
+
+	up_write(&ls->ls_recv_active);
+
+	/*
+	 * This in_recovery lock does two things:
+	 * 1) Keeps this function from returning until all threads are out
+	 *    of locking routines and locking is truly stopped.
+	 * 2) Keeps any new requests from being processed until it's unlocked
+	 *    when recovery is complete.
+	 */
+
+	if (new) {
+		set_bit(LSFL_RECOVER_DOWN, &ls->ls_flags);
+		wake_up_process(ls->ls_recoverd_task);
+		wait_event(ls->ls_recover_lock_wait,
+			   test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags));
+	}
+
+	/*
+	 * The recoverd suspend/resume makes sure that dlm_recoverd (if
+	 * running) has noticed RECOVER_STOP above and quit processing the
+	 * previous recovery.
+	 */
+
+	dlm_recoverd_suspend(ls);
+
+	spin_lock(&ls->ls_recover_lock);
+	kfree(ls->ls_slots);
+	ls->ls_slots = NULL;
+	ls->ls_num_slots = 0;
+	ls->ls_slots_size = 0;
+	ls->ls_recover_status = 0;
+	spin_unlock(&ls->ls_recover_lock);
+
+	dlm_recoverd_resume(ls);
+
+	if (!ls->ls_recover_begin)
+		ls->ls_recover_begin = jiffies;
+
+	/* call recover_prep ops only once and not multiple times
+	 * for each possible dlm_ls_stop() when recovery is already
+	 * stopped.
+	 *
+	 * If we successful was able to clear LSFL_RUNNING bit and
+	 * it was set we know it is the first dlm_ls_stop() call.
+	 */
+	if (new)
+		dlm_lsop_recover_prep(ls);
+
+	return 0;
+}
+
+int dlm_ls_start(struct dlm_ls *ls)
+{
+	struct dlm_recover *rv, *rv_old;
+	struct dlm_config_node *nodes = NULL;
+	int error, count;
+
+	rv = kzalloc(sizeof(*rv), GFP_NOFS);
+	if (!rv)
+		return -ENOMEM;
+
+	error = dlm_config_nodes(ls->ls_name, &nodes, &count);
+	if (error < 0)
+		goto fail_rv;
+
+	spin_lock(&ls->ls_recover_lock);
+
+	/* the lockspace needs to be stopped before it can be started */
+
+	if (!dlm_locking_stopped(ls)) {
+		spin_unlock(&ls->ls_recover_lock);
+		log_error(ls, "start ignored: lockspace running");
+		error = -EINVAL;
+		goto fail;
+	}
+
+	rv->nodes = nodes;
+	rv->nodes_count = count;
+	rv->seq = ++ls->ls_recover_seq;
+	rv_old = ls->ls_recover_args;
+	ls->ls_recover_args = rv;
+	spin_unlock(&ls->ls_recover_lock);
+
+	if (rv_old) {
+		log_error(ls, "unused recovery %llx %d",
+			  (unsigned long long)rv_old->seq, rv_old->nodes_count);
+		kfree(rv_old->nodes);
+		kfree(rv_old);
+	}
+
+	set_bit(LSFL_RECOVER_WORK, &ls->ls_flags);
+	wake_up_process(ls->ls_recoverd_task);
+	return 0;
+
+ fail:
+	kfree(nodes);
+ fail_rv:
+	kfree(rv);
+	return error;
+}
+