[DLM] add lock timeouts and warnings [2/6]
[linux-2.6.git] / fs / dlm / netlink.c
1 /*
2  * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
3  *
4  * This copyrighted material is made available to anyone wishing to use,
5  * modify, copy, or redistribute it subject to the terms and conditions
6  * of the GNU General Public License v.2.
7  */
8
9 #include <net/genetlink.h>
10 #include <linux/dlm.h>
11 #include <linux/dlm_netlink.h>
12
13 #include "dlm_internal.h"
14
15 static uint32_t dlm_nl_seqnum;
16 static uint32_t listener_nlpid;
17
18 static struct genl_family family = {
19         .id             = GENL_ID_GENERATE,
20         .name           = DLM_GENL_NAME,
21         .version        = DLM_GENL_VERSION,
22 };
23
24 static int prepare_data(u8 cmd, struct sk_buff **skbp, size_t size)
25 {
26         struct sk_buff *skb;
27         void *data;
28
29         skb = genlmsg_new(size, GFP_KERNEL);
30         if (!skb)
31                 return -ENOMEM;
32
33         /* add the message headers */
34         data = genlmsg_put(skb, 0, dlm_nl_seqnum++, &family, 0, cmd);
35         if (!data) {
36                 nlmsg_free(skb);
37                 return -EINVAL;
38         }
39
40         *skbp = skb;
41         return 0;
42 }
43
44 static struct dlm_lock_data *mk_data(struct sk_buff *skb)
45 {
46         struct nlattr *ret;
47
48         ret = nla_reserve(skb, DLM_TYPE_LOCK, sizeof(struct dlm_lock_data));
49         if (!ret)
50                 return NULL;
51         return nla_data(ret);
52 }
53
54 static int send_data(struct sk_buff *skb)
55 {
56         struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
57         void *data = genlmsg_data(genlhdr);
58         int rv;
59
60         rv = genlmsg_end(skb, data);
61         if (rv < 0) {
62                 nlmsg_free(skb);
63                 return rv;
64         }
65
66         return genlmsg_unicast(skb, listener_nlpid);
67 }
68
69 static int user_cmd(struct sk_buff *skb, struct genl_info *info)
70 {
71         listener_nlpid = info->snd_pid;
72         printk("user_cmd nlpid %u\n", listener_nlpid);
73         return 0;
74 }
75
76 static struct genl_ops dlm_nl_ops = {
77         .cmd            = DLM_CMD_HELLO,
78         .doit           = user_cmd,
79 };
80
81 int dlm_netlink_init(void)
82 {
83         int rv;
84
85         rv = genl_register_family(&family);
86         if (rv)
87                 return rv;
88
89         rv = genl_register_ops(&family, &dlm_nl_ops);
90         if (rv < 0)
91                 goto err;
92         return 0;
93  err:
94         genl_unregister_family(&family);
95         return rv;
96 }
97
98 void dlm_netlink_exit(void)
99 {
100         genl_unregister_ops(&family, &dlm_nl_ops);
101         genl_unregister_family(&family);
102 }
103
104 static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
105 {
106         struct dlm_rsb *r = lkb->lkb_resource;
107         struct dlm_user_args *ua = (struct dlm_user_args *) lkb->lkb_astparam;
108
109         memset(data, 0, sizeof(struct dlm_lock_data));
110
111         data->version = DLM_LOCK_DATA_VERSION;
112         data->nodeid = lkb->lkb_nodeid;
113         data->ownpid = lkb->lkb_ownpid;
114         data->id = lkb->lkb_id;
115         data->remid = lkb->lkb_remid;
116         data->status = lkb->lkb_status;
117         data->grmode = lkb->lkb_grmode;
118         data->rqmode = lkb->lkb_rqmode;
119         data->timestamp = lkb->lkb_timestamp;
120         if (ua)
121                 data->xid = ua->xid;
122         if (r) {
123                 data->lockspace_id = r->res_ls->ls_global_id;
124                 data->resource_namelen = r->res_length;
125                 memcpy(data->resource_name, r->res_name, r->res_length);
126         }
127 }
128
129 void dlm_timeout_warn(struct dlm_lkb *lkb)
130 {
131         struct dlm_lock_data *data;
132         struct sk_buff *send_skb;
133         size_t size;
134         int rv;
135
136         log_debug(lkb->lkb_resource->res_ls, "timeout_warn %x", lkb->lkb_id);
137
138         size = nla_total_size(sizeof(struct dlm_lock_data)) +
139                nla_total_size(0); /* why this? */
140
141         rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
142         if (rv < 0)
143                 return;
144
145         data = mk_data(send_skb);
146         if (!data) {
147                 nlmsg_free(send_skb);
148                 return;
149         }
150
151         fill_data(data, lkb);
152
153         send_data(send_skb);
154 }
155