This patch adds a dm-mp hardware handler the sends events over netlink
when its error function is called.
Signed-off-by: Mike Anderson <andmike@xxxxxxxxxx>
---
drivers/md/Kconfig | 5
drivers/md/Makefile | 1
drivers/md/dm-evt.c | 330 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/md/dm-mpath.c | 18 --
drivers/md/dm-mpath.h | 19 ++
include/linux/dm-evt.h | 46 ++++++
include/linux/netlink.h | 1
7 files changed, 402 insertions(+), 18 deletions(-)
Index: sas-2.6-patched/drivers/md/dm-evt.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ sas-2.6-patched/drivers/md/dm-evt.c 2005-11-08 23:14:36.000000000 -0800
@@ -0,0 +1,330 @@
+/*
+ * Device Mapper Event Handler (dm-evt)
+ *
+ * Copyright (C) 2005 IBM Corporation
+ * Copyright (C) 2005 Mike Anderson <andmike@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * skb mempool derived from drivers/scsi/scsi_transport_iscsi.c
+ *
+ */
+#include <linux/module.h>
+#include <linux/mempool.h>
+#include <net/tcp.h>
+#include <linux/dm-evt.h>
+#include <linux/time.h>
+#include "dm.h"
+#include "dm-hw-handler.h"
+
+#define MIN_NR_EVT_SKBS 16
+#define HIWAT_EVT_SKBS 32
+
+struct mempool_zone {
+ mempool_t *pool;
+ int allocated;
+ int size;
+ int hiwat;
+ struct list_head freequeue;
+ spinlock_t freelock;
+};
+
+static struct mempool_zone z_dm_evt;
+
+static struct sock *dm_evt_sock;
+static int dm_evt_daemon_pid;
+
+static inline struct list_head *skb_to_lh(struct sk_buff *skb)
+{
+ return (struct list_head *)&skb->cb;
+}
+
+static void* mempool_zone_alloc_skb(unsigned int gfp_mask,
+ void *pool_data)
+{
+ struct mempool_zone *zone = pool_data;
+
+ return alloc_skb(zone->size, gfp_mask);
+}
+
+static void mempool_zone_free_skb(void *element, void *pool_data)
+{
+ kfree_skb(element);
+}
+
+static void
+mempool_zone_complete(struct mempool_zone *zone, int release_all)
+{
+ unsigned long flags;
+ struct list_head *lh, *n;
+
+ spin_lock_irqsave(&zone->freelock, flags);
+ if (zone->allocated) {
+ list_for_each_safe(lh, n, &zone->freequeue) {
+ struct sk_buff *skb =
+ (struct sk_buff *)((char *)lh -
+ offsetof(struct sk_buff, cb));
+ if (skb_shared(skb)) {
+ if (release_all)
+ kfree_skb(skb);
+ else
+ continue;
+ }
+
+ list_del(skb_to_lh(skb));
+ mempool_free(skb, zone->pool);
+ --zone->allocated;
+
+ }
+ }
+ spin_unlock_irqrestore(&zone->freelock, flags);
+}
+
+static int mempool_zone_init(struct mempool_zone *zp, unsigned size,
+ int min_nr, unsigned hiwat)
+{
+ zp->pool = mempool_create(min_nr, mempool_zone_alloc_skb,
+ mempool_zone_free_skb, zp);
+ if (!zp->pool)
+ return -ENOMEM;
+
+ zp->size = size;
+ zp->hiwat = hiwat;
+ zp->allocated = 0;
+ INIT_LIST_HEAD(&zp->freequeue);
+ spin_lock_init(&zp->freelock);
+
+ return 0;
+}
+
+static struct sk_buff* mempool_zone_get_skb(struct mempool_zone *zone)
+{
+ struct sk_buff *skb;
+ unsigned long flags;
+
+ /* Check for ones we can complete before we alloc */
+ mempool_zone_complete(zone, 0);
+
+ skb = mempool_alloc(zone->pool, GFP_ATOMIC);
+ if (skb) {
+ skb_get(skb);
+ spin_lock_irqsave(&z_dm_evt.freelock, flags);
+ list_add(skb_to_lh(skb), &z_dm_evt.freequeue);
+ ++zone->allocated;
+ spin_unlock_irqrestore(&z_dm_evt.freelock, flags);
+ }
+ return skb;
+}
+
+static int dm_evt_create(struct hw_handler *hwh, unsigned argc, char **argv)
+{
+ return 0;
+}
+
+static void dm_evt_destroy(struct hw_handler *hwh)
+{
+ return;
+}
+
+#ifndef BLKERR_IO
+#define BLKERR_IO 0x5A5A5A5A
+#endif
+
+static int dm_evt_send_nl_evt(struct path *path, struct bio *bio)
+{
+ struct sk_buff *skb;
+ struct nlmsghdr *nlh;
+ struct dm_evt_msg *dm_evt;
+ struct timeval tv;
+ int err = -ENOMEM;
+ unsigned int blk_err = BLKERR_IO;
+
+ if (!dm_evt_sock || !dm_evt_daemon_pid)
+ return 0;
+
+ skb = mempool_zone_get_skb(&z_dm_evt);
+ if (!skb)
+ goto out;
+
+ nlh = NLMSG_PUT(skb, dm_evt_daemon_pid, 0, DM_EVENT_PATH_ERR,
+ sizeof(*dm_evt));
+ dm_evt = NLMSG_DATA(nlh);
+ strncpy(dm_evt->dm_name, path->dev->name, sizeof(dm_evt->dm_name));
+ do_gettimeofday(&tv);
+ dm_evt->tv_sec = tv.tv_sec;
+ dm_evt->tv_usec = tv.tv_usec;
+ dm_evt->u.patherr.blk_err = blk_err;
+
+ nlh = (struct nlmsghdr *) skb->data;
+
+ err = netlink_unicast(dm_evt_sock, skb, dm_evt_daemon_pid,
+ MSG_DONTWAIT);
+ if (err < 0)
+ goto unicast_failure;
+ return err;
+
+unicast_failure:
+nlmsg_failure:
+ kfree_skb(skb);
+ mempool_zone_complete(&z_dm_evt, 0);
+out:
+ DMERR("%s: failed %d", __FUNCTION__, err);
+ return err;
+
+}
+
+
+static unsigned dm_evt_error(struct hw_handler *hwh, struct bio *bio)
+{
+ int err;
+ union map_info *info;
+ struct mpath_io *mpio;
+ struct path *path;
+
+ info = dm_get_mapinfo(bio);
+ mpio = info->ptr;
+ path = &mpio->pgpath->path;
+
+ if (path->is_active) {
+ err = dm_evt_send_nl_evt(path, bio);
+ }
+
+ return MP_FAIL_PATH;
+}
+
+#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
+
+static void dm_evt_rcv_msg(struct sk_buff *skb)
+{
+ int pid, flags;
+ struct nlmsghdr *nlh = (struct nlmsghdr *) skb->data;
+
+ if (skb->len >= NLMSG_SPACE(0)) {
+
+ if (nlh->nlmsg_len < sizeof(*nlh) ||
+ skb->len < nlh->nlmsg_len) {
+ return;
+ }
+ pid = nlh->nlmsg_pid;
+ flags = nlh->nlmsg_flags;
+
+ if (security_netlink_recv(skb))
+ RCV_SKB_FAIL(-EPERM);
+
+ if (dm_evt_daemon_pid) {
+ if (dm_evt_daemon_pid != pid) {
+ RCV_SKB_FAIL(-EBUSY);
+ }
+ } else {
+ dm_evt_daemon_pid = pid;
+ }
+
+ if (flags & NLM_F_ACK)
+ netlink_ack(skb, nlh, 0);
+ }
+}
+
+static void dm_evt_rcv(struct sock *sk, int len)
+{
+ struct sk_buff *skb;
+ unsigned int qlen;
+
+ for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
+ skb = skb_dequeue(&sk->sk_receive_queue);
+ dm_evt_rcv_msg(skb);
+ kfree_skb(skb);
+ }
+}
+
+static int dm_evt_rcv_nl_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+ struct netlink_notify *n = ptr;
+
+ if (event == NETLINK_URELEASE &&
+ n->protocol == NETLINK_DM_EVENT && n->pid) {
+ if ( n->pid == dm_evt_daemon_pid ) {
+ dm_evt_daemon_pid = 0;
+ }
+ mempool_zone_complete(&z_dm_evt, 1);
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct hw_handler_type dm_evt_hwh = {
+ .name = "dm-evt",
+ .module = THIS_MODULE,
+ .create = dm_evt_create,
+ .destroy = dm_evt_destroy,
+ .error = dm_evt_error,
+};
+
+static struct notifier_block dm_evt_nl_notifier = {
+ .notifier_call = dm_evt_rcv_nl_event,
+};
+
+static int __init dm_evt_init(void)
+{
+ int err;
+
+ err = netlink_register_notifier(&dm_evt_nl_notifier);
+ if (err)
+ return err;
+
+ dm_evt_sock = netlink_kernel_create(NETLINK_DM_EVENT, 0,
+ dm_evt_rcv, THIS_MODULE);
+ if (!dm_evt_sock) {
+ err = -ENOBUFS;
+ goto unregister_notifier;
+ }
+
+ err = mempool_zone_init(&z_dm_evt, NLMSG_SPACE(sizeof(struct
+ dm_evt_msg)),
+ MIN_NR_EVT_SKBS, HIWAT_EVT_SKBS);
+ if (err)
+ goto release_socket;
+
+ err = dm_register_hw_handler(&dm_evt_hwh);
+ if (err)
+ goto release_zone;
+
+ DMINFO("dm-evt version 0.0.2 loaded");
+
+ return err;
+
+release_zone:
+ mempool_destroy(z_dm_evt.pool);
+release_socket:
+ sock_release(dm_evt_sock->sk_socket);
+unregister_notifier:
+ netlink_unregister_notifier(&dm_evt_nl_notifier);
+ DMERR("%s: failed %d", __FUNCTION__, err);
+ return err;
+}
+
+static void __exit dm_evt_exit(void)
+{
+ dm_unregister_hw_handler(&dm_evt_hwh);
+ mempool_destroy(z_dm_evt.pool);
+ sock_release(dm_evt_sock->sk_socket);
+ netlink_unregister_notifier(&dm_evt_nl_notifier);
+}
+
+module_init(dm_evt_init);
+module_exit(dm_evt_exit);
+
+MODULE_DESCRIPTION(DM_NAME "dm-evt multipath hwh");
+MODULE_AUTHOR("Mike Anderson <andmike@xxxxxxxxxx>");
+MODULE_LICENSE("GPL");
Index: sas-2.6-patched/drivers/md/Makefile
===================================================================
--- sas-2.6-patched.orig/drivers/md/Makefile 2005-11-02 13:59:04.000000000 -0800
+++ sas-2.6-patched/drivers/md/Makefile 2005-11-02 13:59:31.000000000 -0800
@@ -34,6 +34,7 @@ obj-$(CONFIG_BLK_DEV_DM) += dm-mod.o
obj-$(CONFIG_DM_CRYPT) += dm-crypt.o
obj-$(CONFIG_DM_MULTIPATH) += dm-multipath.o dm-round-robin.o
obj-$(CONFIG_DM_MULTIPATH_EMC) += dm-emc.o
+obj-$(CONFIG_DM_MULTIPATH_EVT) += dm-evt.o
obj-$(CONFIG_DM_SNAPSHOT) += dm-snapshot.o
obj-$(CONFIG_DM_MIRROR) += dm-mirror.o
obj-$(CONFIG_DM_ZERO) += dm-zero.o
Index: sas-2.6-patched/include/linux/netlink.h
===================================================================
--- sas-2.6-patched.orig/include/linux/netlink.h 2005-11-02 13:59:04.000000000 -0800
+++ sas-2.6-patched/include/linux/netlink.h 2005-11-02 13:59:31.000000000 -0800
@@ -21,6 +21,7 @@
#define NETLINK_DNRTMSG 14 /* DECnet routing messages */
#define NETLINK_KOBJECT_UEVENT 15 /* Kernel messages to userspace */
#define NETLINK_GENERIC 16
+#define NETLINK_DM_EVENT 17 /* DM Event */
#define MAX_LINKS 32
Index: sas-2.6-patched/include/linux/dm-evt.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ sas-2.6-patched/include/linux/dm-evt.h 2005-11-07 11:28:35.000000000 -0800
@@ -0,0 +1,46 @@
+/*
+ * Device Mapper Event Handler
+ *
+ * Copyright (C) 2005 IBM Corporation
+ * Copyright (C) 2005 Mike Anderson <andmike@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+#ifndef DM_EVENT_H
+#define DM_EVENT_H
+#include <linux/types.h>
+
+#define EVT_DM_NAME_LEN 16
+
+#define DM_EVENT_BASE 10
+enum dm_evt_e {
+ DM_EVENT_UNKOWN = 0,
+ DM_EVENT_PATH_ERR = DM_EVENT_BASE + 1,
+};
+
+struct dm_evt_msg {
+ uint8_t dm_name[EVT_DM_NAME_LEN];
+ uint64_t tv_sec;
+ uint64_t tv_usec;
+
+ union {
+ struct msg_path_err {
+ uint32_t blk_err; /* BLKERR Values */
+ } patherr;
+ } u;
+} __attribute__((aligned(sizeof(uint64_t))));
+
+#endif
Index: sas-2.6-patched/drivers/md/Kconfig
===================================================================
--- sas-2.6-patched.orig/drivers/md/Kconfig 2005-11-02 13:59:04.000000000 -0800
+++ sas-2.6-patched/drivers/md/Kconfig 2005-11-02 13:59:31.000000000 -0800
@@ -235,6 +235,11 @@ config DM_MULTIPATH_EMC
depends on DM_MULTIPATH && BLK_DEV_DM && EXPERIMENTAL
---help---
Multipath support for EMC CX/AX series hardware.
+config DM_MULTIPATH_EVT
+ tristate "Generate netlink events for multipath failures"
+ depends on DM_MULTIPATH && BLK_DEV_DM && EXPERIMENTAL
+ ---help---
+ Multipath support for EMC CX/AX series hardware.
endmenu
Index: sas-2.6-patched/drivers/md/dm-mpath.c
===================================================================
--- sas-2.6-patched.orig/drivers/md/dm-mpath.c 2005-11-02 13:59:04.000000000 -0800
+++ sas-2.6-patched/drivers/md/dm-mpath.c 2005-11-02 13:59:31.000000000 -0800
@@ -23,16 +23,6 @@
#define MESG_STR(x) x, sizeof(x)
-/* Path properties */
-struct pgpath {
- struct list_head list;
-
- struct priority_group *pg; /* Owning PG */
- unsigned fail_count; /* Cumulative failure count */
-
- struct path path;
-};
-
#define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path)
/*
@@ -88,14 +78,6 @@ struct multipath {
mempool_t *mpio_pool;
};
-/*
- * Context information attached to each bio we process.
- */
-struct mpath_io {
- struct pgpath *pgpath;
- struct dm_bio_details details;
-};
-
typedef int (*action_fn) (struct pgpath *pgpath);
#define MIN_IOS 256 /* Mempool size */
Index: sas-2.6-patched/drivers/md/dm-mpath.h
===================================================================
--- sas-2.6-patched.orig/drivers/md/dm-mpath.h 2005-11-02 13:59:04.000000000 -0800
+++ sas-2.6-patched/drivers/md/dm-mpath.h 2005-11-02 13:59:31.000000000 -0800
@@ -8,6 +8,7 @@
#ifndef DM_MPATH_H
#define DM_MPATH_H
+#include "dm-bio-record.h"
struct dm_dev;
@@ -19,6 +20,24 @@ struct path {
void *hwhcontext; /* For hw-handler use */
};
+/* Path properties */
+struct pgpath {
+ struct list_head list;
+
+ struct priority_group *pg; /* Owning PG */
+ unsigned fail_count; /* Cumulative failure count */
+
+ struct path path;
+};
+
+/*
+ * Context information attached to each bio we process.
+ */
+struct mpath_io {
+ struct pgpath *pgpath;
+ struct dm_bio_details details;
+};
+
/* Callback for hwh_pg_init_fn to use when complete */
void dm_pg_init_complete(struct path *path, unsigned err_flags);
--
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