2 * Copyright (C) 2005 Red Hat, Inc. All rights reserved.
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 version 2.
9 #include <linux/miscdevice.h>
10 #include <linux/lock_dlm_plock.h>
15 static spinlock_t ops_lock;
16 static struct list_head send_list;
17 static struct list_head recv_list;
18 static wait_queue_head_t send_wq;
19 static wait_queue_head_t recv_wq;
22 struct list_head list;
24 struct gdlm_plock_info info;
27 static inline void set_version(struct gdlm_plock_info *info)
29 info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
30 info->version[1] = GDLM_PLOCK_VERSION_MINOR;
31 info->version[2] = GDLM_PLOCK_VERSION_PATCH;
34 static int check_version(struct gdlm_plock_info *info)
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,
51 static void send_op(struct plock_op *op)
53 set_version(&op->info);
54 INIT_LIST_HEAD(&op->list);
56 list_add_tail(&op->list, &send_list);
57 spin_unlock(&ops_lock);
61 int gdlm_plock(lm_lockspace_t *lockspace, struct lm_lockname *name,
62 struct file *file, int cmd, struct file_lock *fl)
64 struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
68 op = kzalloc(sizeof(*op), GFP_KERNEL);
72 op->info.optype = GDLM_PLOCK_OP_LOCK;
73 op->info.pid = fl->fl_pid;
74 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;
80 op->info.owner = (__u64)(long) fl->fl_owner;
83 wait_event(recv_wq, (op->done != 0));
86 if (!list_empty(&op->list)) {
87 printk(KERN_INFO "plock op on list\n");
90 spin_unlock(&ops_lock);
95 if (posix_lock_file_wait(file, fl) < 0)
96 log_error("gdlm_plock: vfs lock error %x,%llx",
98 (unsigned long long)name->ln_number);
105 int gdlm_punlock(lm_lockspace_t *lockspace, struct lm_lockname *name,
106 struct file *file, struct file_lock *fl)
108 struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
112 op = kzalloc(sizeof(*op), GFP_KERNEL);
116 if (posix_lock_file_wait(file, fl) < 0)
117 log_error("gdlm_punlock: vfs unlock error %x,%llx",
118 name->ln_type, (unsigned long long)name->ln_number);
120 op->info.optype = GDLM_PLOCK_OP_UNLOCK;
121 op->info.pid = fl->fl_pid;
122 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;
126 op->info.owner = (__u64)(long) fl->fl_owner;
129 wait_event(recv_wq, (op->done != 0));
131 spin_lock(&ops_lock);
132 if (!list_empty(&op->list)) {
133 printk(KERN_INFO "punlock op on list\n");
136 spin_unlock(&ops_lock);
144 int gdlm_plock_get(lm_lockspace_t *lockspace, struct lm_lockname *name,
145 struct file *file, struct file_lock *fl)
147 struct gdlm_ls *ls = (struct gdlm_ls *) lockspace;
151 op = kzalloc(sizeof(*op), GFP_KERNEL);
155 op->info.optype = GDLM_PLOCK_OP_GET;
156 op->info.pid = fl->fl_pid;
157 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;
164 wait_event(recv_wq, (op->done != 0));
166 spin_lock(&ops_lock);
167 if (!list_empty(&op->list)) {
168 printk(KERN_INFO "plock_get op on list\n");
171 spin_unlock(&ops_lock);
176 fl->fl_type = F_UNLCK;
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;
188 /* a read copies out one plock request from the send list */
189 static ssize_t dev_read(struct file *file, char __user *u, size_t count,
192 struct gdlm_plock_info info;
193 struct plock_op *op = NULL;
195 if (count < sizeof(info))
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));
204 spin_unlock(&ops_lock);
209 if (copy_to_user(u, &info, sizeof(info)))
214 /* a write copies in one plock result that should match a plock_op
216 static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
219 struct gdlm_plock_info info;
223 if (count != sizeof(info))
226 if (copy_from_user(&info, u, sizeof(info)))
229 if (check_version(&info))
232 spin_lock(&ops_lock);
233 list_for_each_entry(op, &recv_list, list) {
234 if (op->info.fsid == info.fsid &&
235 op->info.number == info.number &&
236 op->info.owner == info.owner) {
237 list_del_init(&op->list);
240 memcpy(&op->info, &info, sizeof(info));
244 spin_unlock(&ops_lock);
249 printk(KERN_INFO "gdlm dev_write no op %x %llx\n", info.fsid,
250 (unsigned long long)info.number);
254 static unsigned int dev_poll(struct file *file, poll_table *wait)
256 poll_wait(file, &send_wq, wait);
258 spin_lock(&ops_lock);
259 if (!list_empty(&send_list)) {
260 spin_unlock(&ops_lock);
261 return POLLIN | POLLRDNORM;
263 spin_unlock(&ops_lock);
267 static struct file_operations dev_fops = {
274 static struct miscdevice plock_dev_misc = {
275 .minor = MISC_DYNAMIC_MINOR,
276 .name = GDLM_PLOCK_MISC_NAME,
280 int gdlm_plock_init(void)
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);
290 rv = misc_register(&plock_dev_misc);
292 printk(KERN_INFO "gdlm_plock_init: misc_register failed %d",
297 void gdlm_plock_exit(void)
299 if (misc_deregister(&plock_dev_misc) < 0)
300 printk(KERN_INFO "gdlm_plock_exit: misc_deregister failed");