blob: 1acb2519f4391df31778707f91ffa47e60ee3493 [file] [log] [blame]
David Teigland869d81d2006-01-17 08:47:12 +00001/*
2 * Copyright (C) 2005 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 <linux/miscdevice.h>
10#include <linux/lock_dlm_plock.h>
11
12#include "lock_dlm.h"
13
14
15static spinlock_t ops_lock;
16static struct list_head send_list;
17static struct list_head recv_list;
18static wait_queue_head_t send_wq;
19static wait_queue_head_t recv_wq;
20
21struct plock_op {
22 struct list_head list;
23 int done;
24 struct gdlm_plock_info info;
25};
26
27static inline void set_version(struct gdlm_plock_info *info)
28{
29 info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
30 info->version[1] = GDLM_PLOCK_VERSION_MINOR;
31 info->version[2] = GDLM_PLOCK_VERSION_PATCH;
32}
33
34static int check_version(struct gdlm_plock_info *info)
35{
36 if ((GDLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
37 (GDLM_PLOCK_VERSION_MINOR < info->version[1])) {
38 log_error("plock device version mismatch: "
39 "kernel (%u.%u.%u), user (%u.%u.%u)",
40 GDLM_PLOCK_VERSION_MAJOR,
41 GDLM_PLOCK_VERSION_MINOR,
42 GDLM_PLOCK_VERSION_PATCH,
43 info->version[0],
44 info->version[1],
45 info->version[2]);
46 return -EINVAL;
47 }
48 return 0;
49}
50
51static void send_op(struct plock_op *op)
52{
53 set_version(&op->info);
54 INIT_LIST_HEAD(&op->list);
55 spin_lock(&ops_lock);
56 list_add_tail(&op->list, &send_list);
57 spin_unlock(&ops_lock);
58 wake_up(&send_wq);
59}
60
61int gdlm_plock(lm_lockspace_t *lockspace, struct lm_lockname *name,
62 struct file *file, int cmd, struct file_lock *fl)
63{
64 struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
65 struct plock_op *op;
66 int rv;
67
68 op = kzalloc(sizeof(*op), GFP_KERNEL);
69 if (!op)
70 return -ENOMEM;
71
72 op->info.optype = GDLM_PLOCK_OP_LOCK;
David Teigland3a2a9c92006-04-25 15:45:51 -040073 op->info.pid = fl->fl_pid;
David Teigland869d81d2006-01-17 08:47:12 +000074 op->info.ex = (fl->fl_type == F_WRLCK);
75 op->info.wait = IS_SETLKW(cmd);
76 op->info.fsid = ls->id;
77 op->info.number = name->ln_number;
78 op->info.start = fl->fl_start;
79 op->info.end = fl->fl_end;
David Teiglandde9b75d2006-07-28 14:00:20 -050080 op->info.owner = (__u64)(long) fl->fl_owner;
David Teigland869d81d2006-01-17 08:47:12 +000081
82 send_op(op);
83 wait_event(recv_wq, (op->done != 0));
84
85 spin_lock(&ops_lock);
86 if (!list_empty(&op->list)) {
Steven Whitehoused92a8d42006-02-27 10:57:14 -050087 printk(KERN_INFO "plock op on list\n");
David Teigland869d81d2006-01-17 08:47:12 +000088 list_del(&op->list);
89 }
90 spin_unlock(&ops_lock);
91
92 rv = op->info.rv;
93
94 if (!rv) {
95 if (posix_lock_file_wait(file, fl) < 0)
96 log_error("gdlm_plock: vfs lock error %x,%llx",
David Teigland9229f012006-05-24 09:21:30 -040097 name->ln_type,
98 (unsigned long long)name->ln_number);
David Teigland869d81d2006-01-17 08:47:12 +000099 }
100
101 kfree(op);
102 return rv;
103}
104
105int gdlm_punlock(lm_lockspace_t *lockspace, struct lm_lockname *name,
106 struct file *file, struct file_lock *fl)
107{
108 struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
109 struct plock_op *op;
110 int rv;
111
112 op = kzalloc(sizeof(*op), GFP_KERNEL);
113 if (!op)
114 return -ENOMEM;
115
116 if (posix_lock_file_wait(file, fl) < 0)
117 log_error("gdlm_punlock: vfs unlock error %x,%llx",
David Teigland9229f012006-05-24 09:21:30 -0400118 name->ln_type, (unsigned long long)name->ln_number);
David Teigland869d81d2006-01-17 08:47:12 +0000119
120 op->info.optype = GDLM_PLOCK_OP_UNLOCK;
David Teigland3a2a9c92006-04-25 15:45:51 -0400121 op->info.pid = fl->fl_pid;
David Teigland869d81d2006-01-17 08:47:12 +0000122 op->info.fsid = ls->id;
123 op->info.number = name->ln_number;
124 op->info.start = fl->fl_start;
125 op->info.end = fl->fl_end;
David Teiglandde9b75d2006-07-28 14:00:20 -0500126 op->info.owner = (__u64)(long) fl->fl_owner;
David Teigland869d81d2006-01-17 08:47:12 +0000127
128 send_op(op);
129 wait_event(recv_wq, (op->done != 0));
130
131 spin_lock(&ops_lock);
132 if (!list_empty(&op->list)) {
Steven Whitehoused92a8d42006-02-27 10:57:14 -0500133 printk(KERN_INFO "punlock op on list\n");
David Teigland869d81d2006-01-17 08:47:12 +0000134 list_del(&op->list);
135 }
136 spin_unlock(&ops_lock);
137
138 rv = op->info.rv;
139
140 kfree(op);
141 return rv;
142}
143
144int gdlm_plock_get(lm_lockspace_t *lockspace, struct lm_lockname *name,
145 struct file *file, struct file_lock *fl)
146{
147 struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
148 struct plock_op *op;
149 int rv;
150
151 op = kzalloc(sizeof(*op), GFP_KERNEL);
152 if (!op)
153 return -ENOMEM;
154
155 op->info.optype = GDLM_PLOCK_OP_GET;
David Teigland3a2a9c92006-04-25 15:45:51 -0400156 op->info.pid = fl->fl_pid;
David Teigland869d81d2006-01-17 08:47:12 +0000157 op->info.ex = (fl->fl_type == F_WRLCK);
158 op->info.fsid = ls->id;
159 op->info.number = name->ln_number;
160 op->info.start = fl->fl_start;
161 op->info.end = fl->fl_end;
162
163 send_op(op);
164 wait_event(recv_wq, (op->done != 0));
165
166 spin_lock(&ops_lock);
167 if (!list_empty(&op->list)) {
Steven Whitehoused92a8d42006-02-27 10:57:14 -0500168 printk(KERN_INFO "plock_get op on list\n");
David Teigland869d81d2006-01-17 08:47:12 +0000169 list_del(&op->list);
170 }
171 spin_unlock(&ops_lock);
172
173 rv = op->info.rv;
174
175 if (rv == 0)
176 fl->fl_type = F_UNLCK;
177 else if (rv > 0) {
178 fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
179 fl->fl_pid = op->info.pid;
180 fl->fl_start = op->info.start;
181 fl->fl_end = op->info.end;
182 }
183
184 kfree(op);
185 return rv;
186}
187
188/* a read copies out one plock request from the send list */
189static ssize_t dev_read(struct file *file, char __user *u, size_t count,
190 loff_t *ppos)
191{
192 struct gdlm_plock_info info;
193 struct plock_op *op = NULL;
194
195 if (count < sizeof(info))
196 return -EINVAL;
197
198 spin_lock(&ops_lock);
199 if (!list_empty(&send_list)) {
200 op = list_entry(send_list.next, struct plock_op, list);
201 list_move(&op->list, &recv_list);
202 memcpy(&info, &op->info, sizeof(info));
203 }
204 spin_unlock(&ops_lock);
205
206 if (!op)
207 return -EAGAIN;
208
209 if (copy_to_user(u, &info, sizeof(info)))
210 return -EFAULT;
211 return sizeof(info);
212}
213
214/* a write copies in one plock result that should match a plock_op
215 on the recv list */
216static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
217 loff_t *ppos)
218{
219 struct gdlm_plock_info info;
220 struct plock_op *op;
221 int found = 0;
222
223 if (count != sizeof(info))
224 return -EINVAL;
225
226 if (copy_from_user(&info, u, sizeof(info)))
227 return -EFAULT;
228
229 if (check_version(&info))
230 return -EINVAL;
231
232 spin_lock(&ops_lock);
233 list_for_each_entry(op, &recv_list, list) {
234 if (op->info.fsid == info.fsid &&
David Teigland08eac932006-08-04 16:19:20 -0500235 op->info.number == info.number &&
236 op->info.owner == info.owner) {
David Teigland869d81d2006-01-17 08:47:12 +0000237 list_del_init(&op->list);
238 found = 1;
239 op->done = 1;
240 memcpy(&op->info, &info, sizeof(info));
241 break;
242 }
243 }
244 spin_unlock(&ops_lock);
245
246 if (found)
247 wake_up(&recv_wq);
248 else
Steven Whitehoused92a8d42006-02-27 10:57:14 -0500249 printk(KERN_INFO "gdlm dev_write no op %x %llx\n", info.fsid,
David Teigland9229f012006-05-24 09:21:30 -0400250 (unsigned long long)info.number);
David Teigland869d81d2006-01-17 08:47:12 +0000251 return count;
252}
253
254static unsigned int dev_poll(struct file *file, poll_table *wait)
255{
256 poll_wait(file, &send_wq, wait);
257
258 spin_lock(&ops_lock);
259 if (!list_empty(&send_list)) {
260 spin_unlock(&ops_lock);
261 return POLLIN | POLLRDNORM;
262 }
263 spin_unlock(&ops_lock);
264 return 0;
265}
266
267static struct file_operations dev_fops = {
268 .read = dev_read,
269 .write = dev_write,
270 .poll = dev_poll,
271 .owner = THIS_MODULE
272};
273
274static struct miscdevice plock_dev_misc = {
275 .minor = MISC_DYNAMIC_MINOR,
276 .name = GDLM_PLOCK_MISC_NAME,
277 .fops = &dev_fops
278};
279
280int gdlm_plock_init(void)
281{
282 int rv;
283
284 spin_lock_init(&ops_lock);
285 INIT_LIST_HEAD(&send_list);
286 INIT_LIST_HEAD(&recv_list);
287 init_waitqueue_head(&send_wq);
288 init_waitqueue_head(&recv_wq);
289
290 rv = misc_register(&plock_dev_misc);
291 if (rv)
Steven Whitehoused92a8d42006-02-27 10:57:14 -0500292 printk(KERN_INFO "gdlm_plock_init: misc_register failed %d",
293 rv);
David Teigland869d81d2006-01-17 08:47:12 +0000294 return rv;
295}
296
297void gdlm_plock_exit(void)
298{
299 if (misc_deregister(&plock_dev_misc) < 0)
Steven Whitehoused92a8d42006-02-27 10:57:14 -0500300 printk(KERN_INFO "gdlm_plock_exit: misc_deregister failed");
David Teigland869d81d2006-01-17 08:47:12 +0000301}
302