blob: f704458ea5f59a78d8b1121508cc9f22acfe6e45 [file] [log] [blame]
David Teigland869d81d2006-01-17 08:47:12 +00001/*
David Teigland24022112008-03-14 15:09:15 -05002 * Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
David Teigland869d81d2006-01-17 08:47:12 +00003 *
4 * This copyrighted material is made available to anyone wishing to use,
5 * modify, copy, or redistribute it subject to the terms and conditions
Steven Whitehousee9fc2aa2006-09-01 11:05:15 -04006 * of the GNU General Public License version 2.
David Teigland869d81d2006-01-17 08:47:12 +00007 */
8
David Teigland24022112008-03-14 15:09:15 -05009#include <linux/fs.h>
David Teigland869d81d2006-01-17 08:47:12 +000010#include <linux/miscdevice.h>
Al Virobd01f842006-10-19 17:23:57 -040011#include <linux/poll.h>
David Teigland24022112008-03-14 15:09:15 -050012#include <linux/dlm.h>
13#include <linux/dlm_plock.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
David Teigland869d81d2006-01-17 08:47:12 +000015
David Teigland24022112008-03-14 15:09:15 -050016#include "dlm_internal.h"
17#include "lockspace.h"
David Teigland869d81d2006-01-17 08:47:12 +000018
19static spinlock_t ops_lock;
20static struct list_head send_list;
21static struct list_head recv_list;
22static wait_queue_head_t send_wq;
23static wait_queue_head_t recv_wq;
24
25struct plock_op {
26 struct list_head list;
27 int done;
David Teigland24022112008-03-14 15:09:15 -050028 struct dlm_plock_info info;
David Teigland869d81d2006-01-17 08:47:12 +000029};
30
Marc Eshel586759f2006-11-14 16:37:25 -050031struct plock_xop {
32 struct plock_op xop;
33 void *callback;
34 void *fl;
35 void *file;
36 struct file_lock flc;
37};
38
39
David Teigland24022112008-03-14 15:09:15 -050040static inline void set_version(struct dlm_plock_info *info)
David Teigland869d81d2006-01-17 08:47:12 +000041{
David Teigland24022112008-03-14 15:09:15 -050042 info->version[0] = DLM_PLOCK_VERSION_MAJOR;
43 info->version[1] = DLM_PLOCK_VERSION_MINOR;
44 info->version[2] = DLM_PLOCK_VERSION_PATCH;
David Teigland869d81d2006-01-17 08:47:12 +000045}
46
David Teigland24022112008-03-14 15:09:15 -050047static int check_version(struct dlm_plock_info *info)
David Teigland869d81d2006-01-17 08:47:12 +000048{
David Teigland24022112008-03-14 15:09:15 -050049 if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
50 (DLM_PLOCK_VERSION_MINOR < info->version[1])) {
51 log_print("plock device version mismatch: "
David Teigland869d81d2006-01-17 08:47:12 +000052 "kernel (%u.%u.%u), user (%u.%u.%u)",
David Teigland24022112008-03-14 15:09:15 -050053 DLM_PLOCK_VERSION_MAJOR,
54 DLM_PLOCK_VERSION_MINOR,
55 DLM_PLOCK_VERSION_PATCH,
David Teigland869d81d2006-01-17 08:47:12 +000056 info->version[0],
57 info->version[1],
58 info->version[2]);
59 return -EINVAL;
60 }
61 return 0;
62}
63
64static void send_op(struct plock_op *op)
65{
66 set_version(&op->info);
67 INIT_LIST_HEAD(&op->list);
68 spin_lock(&ops_lock);
69 list_add_tail(&op->list, &send_list);
70 spin_unlock(&ops_lock);
71 wake_up(&send_wq);
72}
73
David Teigland901025d2011-03-02 14:20:04 -060074/* If a process was killed while waiting for the only plock on a file,
75 locks_remove_posix will not see any lock on the file so it won't
76 send an unlock-close to us to pass on to userspace to clean up the
77 abandoned waiter. So, we have to insert the unlock-close when the
78 lock call is interrupted. */
79
80static void do_unlock_close(struct dlm_ls *ls, u64 number,
81 struct file *file, struct file_lock *fl)
82{
83 struct plock_op *op;
84
85 op = kzalloc(sizeof(*op), GFP_NOFS);
86 if (!op)
87 return;
88
89 op->info.optype = DLM_PLOCK_OP_UNLOCK;
90 op->info.pid = fl->fl_pid;
91 op->info.fsid = ls->ls_global_id;
92 op->info.number = number;
93 op->info.start = 0;
94 op->info.end = OFFSET_MAX;
J. Bruce Fields8fb47a42011-07-20 20:21:59 -040095 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
David Teigland901025d2011-03-02 14:20:04 -060096 op->info.owner = (__u64) fl->fl_pid;
97 else
98 op->info.owner = (__u64)(long) fl->fl_owner;
99
100 op->info.flags |= DLM_PLOCK_FL_CLOSE;
101 send_op(op);
102}
103
David Teigland24022112008-03-14 15:09:15 -0500104int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
105 int cmd, struct file_lock *fl)
David Teigland869d81d2006-01-17 08:47:12 +0000106{
David Teigland24022112008-03-14 15:09:15 -0500107 struct dlm_ls *ls;
David Teigland869d81d2006-01-17 08:47:12 +0000108 struct plock_op *op;
Marc Eshel586759f2006-11-14 16:37:25 -0500109 struct plock_xop *xop;
David Teigland869d81d2006-01-17 08:47:12 +0000110 int rv;
111
David Teigland24022112008-03-14 15:09:15 -0500112 ls = dlm_find_lockspace_local(lockspace);
113 if (!ls)
114 return -EINVAL;
115
David Teigland573c24c2009-11-30 16:34:43 -0600116 xop = kzalloc(sizeof(*xop), GFP_NOFS);
David Teigland24022112008-03-14 15:09:15 -0500117 if (!xop) {
118 rv = -ENOMEM;
119 goto out;
120 }
David Teigland869d81d2006-01-17 08:47:12 +0000121
Marc Eshel586759f2006-11-14 16:37:25 -0500122 op = &xop->xop;
David Teigland24022112008-03-14 15:09:15 -0500123 op->info.optype = DLM_PLOCK_OP_LOCK;
David Teigland3a2a9c92006-04-25 15:45:51 -0400124 op->info.pid = fl->fl_pid;
David Teigland869d81d2006-01-17 08:47:12 +0000125 op->info.ex = (fl->fl_type == F_WRLCK);
126 op->info.wait = IS_SETLKW(cmd);
David Teigland24022112008-03-14 15:09:15 -0500127 op->info.fsid = ls->ls_global_id;
128 op->info.number = number;
David Teigland869d81d2006-01-17 08:47:12 +0000129 op->info.start = fl->fl_start;
130 op->info.end = fl->fl_end;
J. Bruce Fields8fb47a42011-07-20 20:21:59 -0400131 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
David Teigland2066b582007-12-06 09:35:25 -0600132 /* fl_owner is lockd which doesn't distinguish
133 processes on the nfs client */
134 op->info.owner = (__u64) fl->fl_pid;
J. Bruce Fields8fb47a42011-07-20 20:21:59 -0400135 xop->callback = fl->fl_lmops->lm_grant;
Marc Eshel586759f2006-11-14 16:37:25 -0500136 locks_init_lock(&xop->flc);
137 locks_copy_lock(&xop->flc, fl);
138 xop->fl = fl;
139 xop->file = file;
David Teigland2066b582007-12-06 09:35:25 -0600140 } else {
141 op->info.owner = (__u64)(long) fl->fl_owner;
Marc Eshel586759f2006-11-14 16:37:25 -0500142 xop->callback = NULL;
David Teigland2066b582007-12-06 09:35:25 -0600143 }
David Teigland869d81d2006-01-17 08:47:12 +0000144
145 send_op(op);
Marc Eshel586759f2006-11-14 16:37:25 -0500146
David Teigland901025d2011-03-02 14:20:04 -0600147 if (xop->callback == NULL) {
148 rv = wait_event_killable(recv_wq, (op->done != 0));
149 if (rv == -ERESTARTSYS) {
150 log_debug(ls, "dlm_posix_lock: wait killed %llx",
151 (unsigned long long)number);
152 spin_lock(&ops_lock);
153 list_del(&op->list);
154 spin_unlock(&ops_lock);
155 kfree(xop);
156 do_unlock_close(ls, number, file, fl);
157 goto out;
158 }
159 } else {
Miklos Szeredibde74e42008-07-25 01:48:57 -0700160 rv = FILE_LOCK_DEFERRED;
David Teigland24022112008-03-14 15:09:15 -0500161 goto out;
162 }
David Teigland869d81d2006-01-17 08:47:12 +0000163
164 spin_lock(&ops_lock);
165 if (!list_empty(&op->list)) {
David Teigland24022112008-03-14 15:09:15 -0500166 log_error(ls, "dlm_posix_lock: op on list %llx",
167 (unsigned long long)number);
David Teigland869d81d2006-01-17 08:47:12 +0000168 list_del(&op->list);
169 }
170 spin_unlock(&ops_lock);
171
172 rv = op->info.rv;
173
174 if (!rv) {
175 if (posix_lock_file_wait(file, fl) < 0)
David Teigland24022112008-03-14 15:09:15 -0500176 log_error(ls, "dlm_posix_lock: vfs lock error %llx",
177 (unsigned long long)number);
David Teigland869d81d2006-01-17 08:47:12 +0000178 }
179
Marc Eshel586759f2006-11-14 16:37:25 -0500180 kfree(xop);
David Teigland24022112008-03-14 15:09:15 -0500181out:
182 dlm_put_lockspace(ls);
Marc Eshel586759f2006-11-14 16:37:25 -0500183 return rv;
184}
David Teigland24022112008-03-14 15:09:15 -0500185EXPORT_SYMBOL_GPL(dlm_posix_lock);
Marc Eshel586759f2006-11-14 16:37:25 -0500186
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200187/* Returns failure iff a successful lock operation should be canceled */
David Teigland24022112008-03-14 15:09:15 -0500188static int dlm_plock_callback(struct plock_op *op)
Marc Eshel586759f2006-11-14 16:37:25 -0500189{
190 struct file *file;
191 struct file_lock *fl;
192 struct file_lock *flc;
193 int (*notify)(void *, void *, int) = NULL;
194 struct plock_xop *xop = (struct plock_xop *)op;
195 int rv = 0;
196
197 spin_lock(&ops_lock);
198 if (!list_empty(&op->list)) {
David Teigland24022112008-03-14 15:09:15 -0500199 log_print("dlm_plock_callback: op on list %llx",
200 (unsigned long long)op->info.number);
Marc Eshel586759f2006-11-14 16:37:25 -0500201 list_del(&op->list);
202 }
203 spin_unlock(&ops_lock);
204
205 /* check if the following 2 are still valid or make a copy */
206 file = xop->file;
207 flc = &xop->flc;
208 fl = xop->fl;
209 notify = xop->callback;
210
211 if (op->info.rv) {
David Teigland24179f42009-01-19 13:13:33 -0600212 notify(fl, NULL, op->info.rv);
Marc Eshel586759f2006-11-14 16:37:25 -0500213 goto out;
214 }
215
216 /* got fs lock; bookkeep locally as well: */
217 flc->fl_flags &= ~FL_SLEEP;
218 if (posix_lock_file(file, flc, NULL)) {
219 /*
220 * This can only happen in the case of kmalloc() failure.
221 * The filesystem's own lock is the authoritative lock,
222 * so a failure to get the lock locally is not a disaster.
David Teigland24022112008-03-14 15:09:15 -0500223 * As long as the fs cannot reliably cancel locks (especially
Marc Eshel586759f2006-11-14 16:37:25 -0500224 * in a low-memory situation), we're better off ignoring
225 * this failure than trying to recover.
226 */
David Teigland24022112008-03-14 15:09:15 -0500227 log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
228 (unsigned long long)op->info.number, file, fl);
Marc Eshel586759f2006-11-14 16:37:25 -0500229 }
230
David Teigland24179f42009-01-19 13:13:33 -0600231 rv = notify(fl, NULL, 0);
Marc Eshel586759f2006-11-14 16:37:25 -0500232 if (rv) {
233 /* XXX: We need to cancel the fs lock here: */
David Teigland24022112008-03-14 15:09:15 -0500234 log_print("dlm_plock_callback: lock granted after lock request "
235 "failed; dangling lock!\n");
Marc Eshel586759f2006-11-14 16:37:25 -0500236 goto out;
237 }
238
239out:
240 kfree(xop);
David Teigland869d81d2006-01-17 08:47:12 +0000241 return rv;
242}
243
David Teigland24022112008-03-14 15:09:15 -0500244int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
245 struct file_lock *fl)
David Teigland869d81d2006-01-17 08:47:12 +0000246{
David Teigland24022112008-03-14 15:09:15 -0500247 struct dlm_ls *ls;
David Teigland869d81d2006-01-17 08:47:12 +0000248 struct plock_op *op;
249 int rv;
David Teigland90008312013-04-05 10:57:15 +0100250 unsigned char fl_flags = fl->fl_flags;
David Teigland869d81d2006-01-17 08:47:12 +0000251
David Teigland24022112008-03-14 15:09:15 -0500252 ls = dlm_find_lockspace_local(lockspace);
253 if (!ls)
254 return -EINVAL;
255
David Teigland573c24c2009-11-30 16:34:43 -0600256 op = kzalloc(sizeof(*op), GFP_NOFS);
David Teigland24022112008-03-14 15:09:15 -0500257 if (!op) {
258 rv = -ENOMEM;
259 goto out;
260 }
David Teigland869d81d2006-01-17 08:47:12 +0000261
David Teigland90008312013-04-05 10:57:15 +0100262 /* cause the vfs unlock to return ENOENT if lock is not found */
263 fl->fl_flags |= FL_EXISTS;
264
265 rv = posix_lock_file_wait(file, fl);
266 if (rv == -ENOENT) {
267 rv = 0;
268 goto out_free;
269 }
270 if (rv < 0) {
271 log_error(ls, "dlm_posix_unlock: vfs unlock error %d %llx",
272 rv, (unsigned long long)number);
273 }
David Teigland869d81d2006-01-17 08:47:12 +0000274
David Teigland24022112008-03-14 15:09:15 -0500275 op->info.optype = DLM_PLOCK_OP_UNLOCK;
David Teigland3a2a9c92006-04-25 15:45:51 -0400276 op->info.pid = fl->fl_pid;
David Teigland24022112008-03-14 15:09:15 -0500277 op->info.fsid = ls->ls_global_id;
278 op->info.number = number;
David Teigland869d81d2006-01-17 08:47:12 +0000279 op->info.start = fl->fl_start;
280 op->info.end = fl->fl_end;
J. Bruce Fields8fb47a42011-07-20 20:21:59 -0400281 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
David Teigland2066b582007-12-06 09:35:25 -0600282 op->info.owner = (__u64) fl->fl_pid;
283 else
284 op->info.owner = (__u64)(long) fl->fl_owner;
David Teigland869d81d2006-01-17 08:47:12 +0000285
David Teigland901025d2011-03-02 14:20:04 -0600286 if (fl->fl_flags & FL_CLOSE) {
287 op->info.flags |= DLM_PLOCK_FL_CLOSE;
288 send_op(op);
289 rv = 0;
290 goto out;
291 }
292
David Teigland869d81d2006-01-17 08:47:12 +0000293 send_op(op);
294 wait_event(recv_wq, (op->done != 0));
295
296 spin_lock(&ops_lock);
297 if (!list_empty(&op->list)) {
David Teigland24022112008-03-14 15:09:15 -0500298 log_error(ls, "dlm_posix_unlock: op on list %llx",
299 (unsigned long long)number);
David Teigland869d81d2006-01-17 08:47:12 +0000300 list_del(&op->list);
301 }
302 spin_unlock(&ops_lock);
303
304 rv = op->info.rv;
305
Marc Eshel586759f2006-11-14 16:37:25 -0500306 if (rv == -ENOENT)
307 rv = 0;
308
David Teigland90008312013-04-05 10:57:15 +0100309out_free:
David Teigland869d81d2006-01-17 08:47:12 +0000310 kfree(op);
David Teigland24022112008-03-14 15:09:15 -0500311out:
312 dlm_put_lockspace(ls);
David Teigland90008312013-04-05 10:57:15 +0100313 fl->fl_flags = fl_flags;
David Teigland869d81d2006-01-17 08:47:12 +0000314 return rv;
315}
David Teigland24022112008-03-14 15:09:15 -0500316EXPORT_SYMBOL_GPL(dlm_posix_unlock);
David Teigland869d81d2006-01-17 08:47:12 +0000317
David Teigland24022112008-03-14 15:09:15 -0500318int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
319 struct file_lock *fl)
David Teigland869d81d2006-01-17 08:47:12 +0000320{
David Teigland24022112008-03-14 15:09:15 -0500321 struct dlm_ls *ls;
David Teigland869d81d2006-01-17 08:47:12 +0000322 struct plock_op *op;
323 int rv;
324
David Teigland24022112008-03-14 15:09:15 -0500325 ls = dlm_find_lockspace_local(lockspace);
326 if (!ls)
327 return -EINVAL;
David Teigland869d81d2006-01-17 08:47:12 +0000328
David Teigland573c24c2009-11-30 16:34:43 -0600329 op = kzalloc(sizeof(*op), GFP_NOFS);
David Teigland24022112008-03-14 15:09:15 -0500330 if (!op) {
331 rv = -ENOMEM;
332 goto out;
333 }
334
335 op->info.optype = DLM_PLOCK_OP_GET;
David Teigland3a2a9c92006-04-25 15:45:51 -0400336 op->info.pid = fl->fl_pid;
David Teigland869d81d2006-01-17 08:47:12 +0000337 op->info.ex = (fl->fl_type == F_WRLCK);
David Teigland24022112008-03-14 15:09:15 -0500338 op->info.fsid = ls->ls_global_id;
339 op->info.number = number;
David Teigland869d81d2006-01-17 08:47:12 +0000340 op->info.start = fl->fl_start;
341 op->info.end = fl->fl_end;
J. Bruce Fields8fb47a42011-07-20 20:21:59 -0400342 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
David Teigland2066b582007-12-06 09:35:25 -0600343 op->info.owner = (__u64) fl->fl_pid;
344 else
345 op->info.owner = (__u64)(long) fl->fl_owner;
Marc Eshel586759f2006-11-14 16:37:25 -0500346
David Teigland869d81d2006-01-17 08:47:12 +0000347 send_op(op);
348 wait_event(recv_wq, (op->done != 0));
349
350 spin_lock(&ops_lock);
351 if (!list_empty(&op->list)) {
David Teigland24022112008-03-14 15:09:15 -0500352 log_error(ls, "dlm_posix_get: op on list %llx",
353 (unsigned long long)number);
David Teigland869d81d2006-01-17 08:47:12 +0000354 list_del(&op->list);
355 }
356 spin_unlock(&ops_lock);
357
David Teiglanda7a2ff82007-06-08 17:01:40 -0500358 /* info.rv from userspace is 1 for conflict, 0 for no-conflict,
359 -ENOENT if there are no locks on the file */
360
David Teigland869d81d2006-01-17 08:47:12 +0000361 rv = op->info.rv;
362
Marc Eshel586759f2006-11-14 16:37:25 -0500363 fl->fl_type = F_UNLCK;
364 if (rv == -ENOENT)
365 rv = 0;
David Teiglanda7a2ff82007-06-08 17:01:40 -0500366 else if (rv > 0) {
Jeff Layton20d5a392009-01-21 11:34:50 -0500367 locks_init_lock(fl);
David Teigland869d81d2006-01-17 08:47:12 +0000368 fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
Jeff Layton20d5a392009-01-21 11:34:50 -0500369 fl->fl_flags = FL_POSIX;
David Teigland869d81d2006-01-17 08:47:12 +0000370 fl->fl_pid = op->info.pid;
371 fl->fl_start = op->info.start;
372 fl->fl_end = op->info.end;
David Teiglanda7a2ff82007-06-08 17:01:40 -0500373 rv = 0;
David Teigland869d81d2006-01-17 08:47:12 +0000374 }
375
376 kfree(op);
David Teigland24022112008-03-14 15:09:15 -0500377out:
378 dlm_put_lockspace(ls);
David Teigland869d81d2006-01-17 08:47:12 +0000379 return rv;
380}
David Teigland24022112008-03-14 15:09:15 -0500381EXPORT_SYMBOL_GPL(dlm_posix_get);
David Teigland869d81d2006-01-17 08:47:12 +0000382
383/* a read copies out one plock request from the send list */
384static ssize_t dev_read(struct file *file, char __user *u, size_t count,
385 loff_t *ppos)
386{
David Teigland24022112008-03-14 15:09:15 -0500387 struct dlm_plock_info info;
David Teigland869d81d2006-01-17 08:47:12 +0000388 struct plock_op *op = NULL;
389
390 if (count < sizeof(info))
391 return -EINVAL;
392
393 spin_lock(&ops_lock);
394 if (!list_empty(&send_list)) {
395 op = list_entry(send_list.next, struct plock_op, list);
David Teigland901025d2011-03-02 14:20:04 -0600396 if (op->info.flags & DLM_PLOCK_FL_CLOSE)
397 list_del(&op->list);
398 else
399 list_move(&op->list, &recv_list);
David Teigland869d81d2006-01-17 08:47:12 +0000400 memcpy(&info, &op->info, sizeof(info));
401 }
402 spin_unlock(&ops_lock);
403
404 if (!op)
405 return -EAGAIN;
406
David Teigland901025d2011-03-02 14:20:04 -0600407 /* there is no need to get a reply from userspace for unlocks
408 that were generated by the vfs cleaning up for a close
409 (the process did not make an unlock call). */
410
411 if (op->info.flags & DLM_PLOCK_FL_CLOSE)
412 kfree(op);
413
David Teigland869d81d2006-01-17 08:47:12 +0000414 if (copy_to_user(u, &info, sizeof(info)))
415 return -EFAULT;
416 return sizeof(info);
417}
418
419/* a write copies in one plock result that should match a plock_op
420 on the recv list */
421static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
422 loff_t *ppos)
423{
David Teigland24022112008-03-14 15:09:15 -0500424 struct dlm_plock_info info;
David Teigland869d81d2006-01-17 08:47:12 +0000425 struct plock_op *op;
David Teiglandc78a87d2009-06-18 13:20:24 -0500426 int found = 0, do_callback = 0;
David Teigland869d81d2006-01-17 08:47:12 +0000427
428 if (count != sizeof(info))
429 return -EINVAL;
430
431 if (copy_from_user(&info, u, sizeof(info)))
432 return -EFAULT;
433
434 if (check_version(&info))
435 return -EINVAL;
436
437 spin_lock(&ops_lock);
438 list_for_each_entry(op, &recv_list, list) {
David Teiglandc78a87d2009-06-18 13:20:24 -0500439 if (op->info.fsid == info.fsid &&
440 op->info.number == info.number &&
David Teigland08eac932006-08-04 16:19:20 -0500441 op->info.owner == info.owner) {
David Teiglandc78a87d2009-06-18 13:20:24 -0500442 struct plock_xop *xop = (struct plock_xop *)op;
David Teigland869d81d2006-01-17 08:47:12 +0000443 list_del_init(&op->list);
David Teigland869d81d2006-01-17 08:47:12 +0000444 memcpy(&op->info, &info, sizeof(info));
David Teiglandc78a87d2009-06-18 13:20:24 -0500445 if (xop->callback)
446 do_callback = 1;
447 else
448 op->done = 1;
449 found = 1;
David Teigland869d81d2006-01-17 08:47:12 +0000450 break;
451 }
452 }
453 spin_unlock(&ops_lock);
454
Marc Eshel586759f2006-11-14 16:37:25 -0500455 if (found) {
David Teiglandc78a87d2009-06-18 13:20:24 -0500456 if (do_callback)
David Teigland817d10b2008-05-13 14:28:26 -0500457 dlm_plock_callback(op);
Marc Eshel586759f2006-11-14 16:37:25 -0500458 else
459 wake_up(&recv_wq);
460 } else
David Teigland24022112008-03-14 15:09:15 -0500461 log_print("dev_write no op %x %llx", info.fsid,
462 (unsigned long long)info.number);
David Teigland869d81d2006-01-17 08:47:12 +0000463 return count;
464}
465
466static unsigned int dev_poll(struct file *file, poll_table *wait)
467{
Denis Chengcee23c72007-07-25 17:53:58 +0800468 unsigned int mask = 0;
469
David Teigland869d81d2006-01-17 08:47:12 +0000470 poll_wait(file, &send_wq, wait);
471
472 spin_lock(&ops_lock);
Denis Chengcee23c72007-07-25 17:53:58 +0800473 if (!list_empty(&send_list))
474 mask = POLLIN | POLLRDNORM;
David Teigland869d81d2006-01-17 08:47:12 +0000475 spin_unlock(&ops_lock);
Denis Chengcee23c72007-07-25 17:53:58 +0800476
477 return mask;
David Teigland869d81d2006-01-17 08:47:12 +0000478}
479
Arjan van de Ven00977a52007-02-12 00:55:34 -0800480static const struct file_operations dev_fops = {
David Teigland869d81d2006-01-17 08:47:12 +0000481 .read = dev_read,
482 .write = dev_write,
483 .poll = dev_poll,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200484 .owner = THIS_MODULE,
485 .llseek = noop_llseek,
David Teigland869d81d2006-01-17 08:47:12 +0000486};
487
488static struct miscdevice plock_dev_misc = {
489 .minor = MISC_DYNAMIC_MINOR,
David Teigland24022112008-03-14 15:09:15 -0500490 .name = DLM_PLOCK_MISC_NAME,
David Teigland869d81d2006-01-17 08:47:12 +0000491 .fops = &dev_fops
492};
493
David Teigland24022112008-03-14 15:09:15 -0500494int dlm_plock_init(void)
David Teigland869d81d2006-01-17 08:47:12 +0000495{
496 int rv;
497
498 spin_lock_init(&ops_lock);
499 INIT_LIST_HEAD(&send_list);
500 INIT_LIST_HEAD(&recv_list);
501 init_waitqueue_head(&send_wq);
502 init_waitqueue_head(&recv_wq);
503
504 rv = misc_register(&plock_dev_misc);
505 if (rv)
David Teigland24022112008-03-14 15:09:15 -0500506 log_print("dlm_plock_init: misc_register failed %d", rv);
David Teigland869d81d2006-01-17 08:47:12 +0000507 return rv;
508}
509
David Teigland24022112008-03-14 15:09:15 -0500510void dlm_plock_exit(void)
David Teigland869d81d2006-01-17 08:47:12 +0000511{
512 if (misc_deregister(&plock_dev_misc) < 0)
David Teigland24022112008-03-14 15:09:15 -0500513 log_print("dlm_plock_exit: misc_deregister failed");
David Teigland869d81d2006-01-17 08:47:12 +0000514}
515