[dm-devel] [PATCH RFC 1/4] dm-netlink skeleton support
Mike Anderson
andmike at us.ibm.com
Wed Nov 30 08:25:03 UTC 2005
This patch adds a dm-netlink skeleton support to the Makefile, Kconfig,
and the dm directory. This base dm-netlink file only contains the mempool
support.
Signed-off-by: Mike Anderson <andmike at us.ibm.com>
drivers/md/Kconfig | 6 ++
drivers/md/Makefile | 3 +
drivers/md/dm-netlink.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/netlink.h | 1
4 files changed, 154 insertions(+)
Index: linux-2.6.15-rc1-patched/drivers/md/dm-netlink.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15-rc1-patched/drivers/md/dm-netlink.c 2005-11-29 23:50:01.000000000 -0800
@@ -0,0 +1,144 @@
+/*
+ * Device Mapper Netlink Support (dm-netlink)
+ *
+ * Copyright (C) 2005 IBM Corporation
+ * Author: Mike Anderson <andmike at us.ibm.com>
+ * skb mempool derived from drivers/scsi/scsi_transport_iscsi.c
+ *
+ * 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.
+ *
+ */
+#include <linux/module.h>
+#include <linux/mempool.h>
+#include <linux/time.h>
+#include <linux/jiffies.h>
+#include <linux/security.h>
+#include <net/sock.h>
+#include <net/netlink.h>
+
+#define MIN_EVT_SKBS 16
+#define HIWAT_EVT_SKBS 32
+#define EVT_SKB_SIZE NLMSG_SPACE(128)
+
+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 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->size = size;
+ zp->hiwat = hiwat;
+ zp->allocated = 0;
+ INIT_LIST_HEAD(&zp->freequeue);
+ spin_lock_init(&zp->freelock);
+
+ zp->pool = mempool_create(min_nr, mempool_zone_alloc_skb,
+ mempool_zone_free_skb, zp);
+ if (!zp->pool)
+ return -ENOMEM;
+
+ 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;
+}
+
+int __init dm_nl_init(void)
+{
+ int err;
+
+ err = mempool_zone_init(&z_dm_evt, EVT_SKB_SIZE,
+ MIN_EVT_SKBS, HIWAT_EVT_SKBS);
+ if (!err)
+ printk(KERN_DEBUG "dm-netlink version 0.0.1 loaded\n");
+
+ return err;
+
+}
+
+void dm_nl_exit(void)
+{
+ mempool_destroy(z_dm_evt.pool);
+}
Index: linux-2.6.15-rc1-patched/include/linux/netlink.h
===================================================================
--- linux-2.6.15-rc1-patched.orig/include/linux/netlink.h 2005-11-11 18:51:47.000000000 -0800
+++ linux-2.6.15-rc1-patched/include/linux/netlink.h 2005-11-29 22:48:29.000000000 -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 17 /* Device Mapper */
#define MAX_LINKS 32
Index: linux-2.6.15-rc1-patched/drivers/md/Makefile
===================================================================
--- linux-2.6.15-rc1-patched.orig/drivers/md/Makefile 2005-08-28 17:51:43.000000000 -0700
+++ linux-2.6.15-rc1-patched/drivers/md/Makefile 2005-11-29 22:48:29.000000000 -0800
@@ -37,6 +37,9 @@ obj-$(CONFIG_DM_MULTIPATH_EMC) += dm-emc
obj-$(CONFIG_DM_SNAPSHOT) += dm-snapshot.o
obj-$(CONFIG_DM_MIRROR) += dm-mirror.o
obj-$(CONFIG_DM_ZERO) += dm-zero.o
+ifeq ($(CONFIG_DM_NL_SUPPORT),y)
+ dm-mod-objs += dm-netlink.o
+endif
quiet_cmd_unroll = UNROLL $@
cmd_unroll = $(PERL) $(srctree)/$(src)/unroll.pl $(UNROLL) \
Index: linux-2.6.15-rc1-patched/drivers/md/Kconfig
===================================================================
--- linux-2.6.15-rc1-patched.orig/drivers/md/Kconfig 2005-06-17 17:21:30.000000000 -0700
+++ linux-2.6.15-rc1-patched/drivers/md/Kconfig 2005-11-29 22:48:29.000000000 -0800
@@ -236,5 +236,11 @@ config DM_MULTIPATH_EMC
---help---
Multipath support for EMC CX/AX series hardware.
+config DM_NL_SUPPORT
+ bool "DM Netlink Support (EXPERIMENTAL)"
+ depends on BLK_DEV_DM && EXPERIMENTAL
+ ---help---
+ Netlink events for dm devices.
+
endmenu
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