[dm-devel] [PATCH 2/4] dm-netlink: Add support for the event functions
Mike Anderson
andmike at us.ibm.com
Tue Jan 9 09:32:43 UTC 2007
From: Mike Anderson <andmike at us.ibm.com>
This patch adds support for the dm_path_event dm_send_event functions which
create and send netlink attribute events.
Signed-off-by: Mike Anderson <andmike at us.ibm.com>
---
drivers/md/dm-netlink.c | 204 ++++++++++++++++++++++++++++++++++++++++++++-
drivers/md/dm-netlink.h | 9 +
drivers/md/dm.c | 26 +++++
drivers/md/dm.h | 2
include/linux/dm-netlink.h | 50 +++++++++++
5 files changed, 289 insertions(+), 2 deletions(-)
Index: linux-2.6-patched/drivers/md/dm-netlink.c
===================================================================
--- linux-2.6-patched.orig/drivers/md/dm-netlink.c 2007-01-09 01:11:57.000000000 -0800
+++ linux-2.6-patched/drivers/md/dm-netlink.c 2007-01-09 01:12:02.000000000 -0800
@@ -79,13 +79,213 @@
return NULL;
}
+static struct sock *dm_netlink_sock;
+static u32 dm_netlink_daemon_pid;
+static DEFINE_SPINLOCK(pid_lock);
+
+static u64 dm_event_seqnum;
+static DEFINE_SPINLOCK(sequence_lock);
+
+static struct dm_event *dm_netlink_build_path_msg(char* dm_name, int type, int
+ nr_valid_paths)
+{
+ struct dm_event *evt;
+ struct nlmsghdr *nlh;
+ struct dm_netlink_msghdr *dm_nlh;
+ u64 seq;
+ struct timeval tv;
+ int err = -ENOBUFS;
+
+ evt = dme_cache_event_get(&dme_cache);
+ if (!evt) {
+ printk(KERN_ERR "%s: dme_cache_event_get %d\n",
+ __FUNCTION__, err);
+ err = -ENOMEM;
+ goto out;
+ }
+
+ nlh = nlmsg_put(evt->skb, 0, 0, DM_EVENT,
+ NLMSG_ALIGN(sizeof(*dm_nlh)), 0);
+ if (!nlh)
+ goto nla_put_failure;
+
+ dm_nlh = nlmsg_data(nlh);
+ dm_nlh->type = type;
+ dm_nlh->version = DM_E_ATTR_MAX;
+
+ spin_lock(&sequence_lock);
+ seq = ++dm_event_seqnum;
+ spin_unlock(&sequence_lock);
+ do_gettimeofday(&tv);
+
+ NLA_PUT_U64(evt->skb, DM_E_ATTR_SEQNUM, seq);
+ NLA_PUT_U64(evt->skb, DM_E_ATTR_TSSEC, tv.tv_sec);
+ NLA_PUT_U64(evt->skb, DM_E_ATTR_TSUSEC, tv.tv_usec);
+ NLA_PUT_STRING(evt->skb, DM_E_ATTR_DMNAME, dm_name);
+ NLA_PUT_U32(evt->skb, DM_E_ATTR_VLDPTHS, nr_valid_paths);
+
+ return evt;
+
+nla_put_failure:
+ printk(KERN_ERR "%s: nla_put_failure\n", __FUNCTION__);
+ nlmsg_free(evt->skb);
+ dme_cache_event_put(evt);
+out:
+ return ERR_PTR(err);
+
+}
+
+/**
+ * dm_send_event - called to send a completed event message
+ *
+ * @md_name: string containing md device name
+ * @evt: pointer of event to send
+ *
+ **/
+void dm_send_event(char *md_name, struct dm_event *evt)
+{
+ struct nlmsghdr *nlh = (struct nlmsghdr *) evt->skb->data;
+ int err;
+
+ NLA_PUT_STRING(evt->skb, DM_E_ATTR_MDNAME, md_name);
+ nlmsg_end(evt->skb, nlh);
+
+ spin_lock(&pid_lock);
+ nlh->nlmsg_pid = dm_netlink_daemon_pid;
+ spin_unlock(&pid_lock);
+
+ if (!nlh->nlmsg_pid)
+ goto no_pid;
+
+ err = nlmsg_unicast(dm_netlink_sock, evt->skb, nlh->nlmsg_pid);
+
+ if (err && (err != -ESRCH))
+ printk(KERN_ERR "%s: nlmsg_unicast failed %d\n",
+ __FUNCTION__, err);
+ goto out;
+
+nla_put_failure:
+ printk(KERN_ERR "%s: nla_put_failure\n", __FUNCTION__);
+no_pid:
+ nlmsg_free(evt->skb);
+out:
+ dme_cache_event_put(evt);
+ return;
+}
+EXPORT_SYMBOL(dm_send_event);
+
+/**
+ * dm_path_event - called to create a new path event and queue it
+ *
+ * @evt_type: enum of path event type
+ * @t: pointer to a dm_table
+ * @dm_name: dm name string
+ * @nr_valid_paths: number of valid paths remaining
+ *
+ **/
+void dm_path_event(enum dm_event_type evt_type, struct dm_table *t,
+ char* dm_name, int nr_valid_paths)
+{
+ struct dm_event *evt;
+ evt = dm_netlink_build_path_msg(dm_name, evt_type, nr_valid_paths);
+
+ if (evt) {
+ struct mapped_device *md = dm_table_get_md(t);
+ dm_add_event(md, evt);
+ dm_put(md);
+ }
+
+ return;
+}
+
+EXPORT_SYMBOL(dm_path_event);
+
+static int dm_netlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ int *errp)
+{
+ int ret = -1;
+
+ if (security_netlink_recv(skb, CAP_SYS_ADMIN)) {
+ *errp = -EPERM;
+ goto out;
+ }
+
+ spin_lock(&pid_lock);
+ if (dm_netlink_daemon_pid) {
+ if (dm_netlink_daemon_pid != nlh->nlmsg_pid) {
+ *errp = -EBUSY;
+ goto out;
+ }
+ } else {
+ dm_netlink_daemon_pid = nlh->nlmsg_pid;
+ }
+ spin_unlock(&pid_lock);
+
+ ret = 0;
+out:
+ return ret;
+
+}
+
+static void dm_netlink_rcv(struct sock *sk, int len)
+{
+ unsigned int qlen;
+
+ do {
+ netlink_run_queue(sk, &qlen, &dm_netlink_rcv_msg);
+ } while (qlen);
+
+}
+
+static int dm_netlink_rcv_event(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ struct netlink_notify *n = ptr;
+
+ spin_lock(&pid_lock);
+ if (event == NETLINK_URELEASE &&
+ n->protocol == NETLINK_DM && n->pid) {
+ if ( n->pid == dm_netlink_daemon_pid ) {
+ dm_netlink_daemon_pid = 0;
+ }
+ }
+ spin_unlock(&pid_lock);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block dm_netlink_notifier = {
+ .notifier_call = dm_netlink_rcv_event,
+};
+
+
int __init dm_netlink_init(void)
{
int err;
+ err = netlink_register_notifier(&dm_netlink_notifier);
+ if (err)
+ return err;
+
+ dm_netlink_sock = netlink_kernel_create(NETLINK_DM, 0,
+ dm_netlink_rcv, THIS_MODULE);
+ if (!dm_netlink_sock) {
+ err = -ENOBUFS;
+ goto notifier_out;
+ }
err = dme_cache_init(&dme_cache, EVENT_SKB_SIZE);
- if (!err)
- printk(KERN_DEBUG "dm-netlink version 0.0.6 loaded\n");
+ if (err)
+ goto socket_out;
+
+ printk(KERN_DEBUG "dm-netlink version 0.0.7 loaded\n");
+
+ return err;
+
+socket_out:
+ sock_release(dm_netlink_sock->sk_socket);
+notifier_out:
+ netlink_unregister_notifier(&dm_netlink_notifier);
+ printk(KERN_ERR "%s: failed %d\n", __FUNCTION__, err);
return err;
}
Index: linux-2.6-patched/drivers/md/dm-netlink.h
===================================================================
--- linux-2.6-patched.orig/drivers/md/dm-netlink.h 2007-01-09 01:11:57.000000000 -0800
+++ linux-2.6-patched/drivers/md/dm-netlink.h 2007-01-09 01:12:02.000000000 -0800
@@ -21,6 +21,8 @@
#ifndef DM_NETLINK_H
#define DM_NETLINK_H
+#include <linux/dm-netlink.h>
+
struct dm_event {
void *cdata;
struct sk_buff *skb;
@@ -28,9 +30,16 @@
};
#ifdef CONFIG_DM_NETLINK_EVENT
+void dm_send_event(char *, struct dm_event *);
+void dm_path_event(enum dm_event_type, struct dm_table *, char *, int);
int dm_netlink_init(void);
void dm_netlink_exit(void);
#else
+static inline void dm_send_event(char *, struct dm_event *)
+{ }
+static inline void dm_path_event(enum dm_event_type, struct dm_table *, char *,
+ int)
+{ }
static inline int __init dm_netlink_init(void)
{
return 0;
Index: linux-2.6-patched/include/linux/dm-netlink.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-patched/include/linux/dm-netlink.h 2007-01-09 01:12:02.000000000 -0800
@@ -0,0 +1,50 @@
+/*
+ * Device Mapper Netlink Support
+ *
+ * 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.
+ *
+ * Copyright IBM Corporation, 2005, 2006
+ * Author: Mike Anderson <andmike at us.ibm.com>
+ */
+#ifndef LINUX_DM_NETLINK_H
+#define LINUX_DM_NETLINK_H
+
+#define DM_EVENT NLMSG_MIN_TYPE + 0x1
+
+enum dm_event_type {
+ DM_EVENT_FAIL_PATH = 1,
+ DM_EVENT_REINSTATE_PATH = 2,
+ DM_EVENT_MAX,
+};
+
+enum dm_event_attr {
+ DM_E_ATTR_SEQNUM = 1,
+ DM_E_ATTR_TSSEC = 2,
+ DM_E_ATTR_TSUSEC = 3,
+ DM_E_ATTR_DMNAME = 4,
+ DM_E_ATTR_BLKERR = 5,
+ DM_E_ATTR_VLDPTHS = 6,
+ DM_E_ATTR_MDNAME = 7,
+ DM_E_ATTR_MAX,
+};
+
+struct dm_netlink_msghdr {
+ uint16_t type;
+ uint16_t version;
+ uint16_t reserved1;
+ uint16_t reserved2;
+} __attribute__((aligned(sizeof(uint64_t))));
+
+#endif /* LINUX_DM_NETLINK_H */
Index: linux-2.6-patched/drivers/md/dm.c
===================================================================
--- linux-2.6-patched.orig/drivers/md/dm.c 2007-01-09 01:11:57.000000000 -0800
+++ linux-2.6-patched/drivers/md/dm.c 2007-01-09 01:12:02.000000000 -0800
@@ -112,6 +112,8 @@
*/
atomic_t event_nr;
wait_queue_head_t eventq;
+ struct list_head event_list;
+ spinlock_t event_lock;
/*
* freeze/thaw support require holding onto a super block
@@ -993,6 +995,8 @@
atomic_set(&md->holders, 1);
atomic_set(&md->open_count, 0);
atomic_set(&md->event_nr, 0);
+ INIT_LIST_HEAD(&md->event_list);
+ spin_lock_init(&md->event_lock);
md->queue = blk_alloc_queue(GFP_KERNEL);
if (!md->queue)
@@ -1091,6 +1095,18 @@
static void event_callback(void *context)
{
struct mapped_device *md = (struct mapped_device *) context;
+ unsigned long flags;
+ struct dm_event *evt, *next;
+ LIST_HEAD(events);
+
+ spin_lock_irqsave(&md->event_lock, flags);
+ list_splice_init(&md->event_list, &events);
+ spin_unlock_irqrestore(&md->event_lock, flags);
+
+ list_for_each_entry_safe(evt, next, &events, elist) {
+ list_del_init(&evt->elist);
+ dm_send_event(md->name, evt);
+ }
atomic_inc(&md->event_nr);
wake_up(&md->eventq);
@@ -1507,6 +1523,16 @@
(event_nr != atomic_read(&md->event_nr)));
}
+void dm_add_event(struct mapped_device *md, struct dm_event *evt)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&md->event_lock, flags);
+ list_add(&evt->elist, &md->event_list);
+ spin_unlock_irqrestore(&md->event_lock, flags);
+
+}
+
/*
* The gendisk is only valid as long as you have a reference
* count on 'md'.
Index: linux-2.6-patched/drivers/md/dm.h
===================================================================
--- linux-2.6-patched.orig/drivers/md/dm.h 2007-01-09 01:11:57.000000000 -0800
+++ linux-2.6-patched/drivers/md/dm.h 2007-01-09 01:12:02.000000000 -0800
@@ -152,4 +152,6 @@
int dm_open_count(struct mapped_device *md);
int dm_lock_for_deletion(struct mapped_device *md);
+void dm_add_event(struct mapped_device *md, struct dm_event *evt);
+
#endif
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