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1/*
2 * Copyright (C) 2005-2008 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 version 2.
7 */
8
9#include <linux/fs.h>
10#include <linux/miscdevice.h>
11#include <linux/poll.h>
12#include <linux/dlm.h>
13#include <linux/dlm_plock.h>
14#include <linux/slab.h>
15
16#include "dlm_internal.h"
17#include "lockspace.h"
18
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;
28 struct dlm_plock_info info;
29};
30
31struct plock_xop {
32 struct plock_op xop;
33 void *callback;
34 void *fl;
35 void *file;
36 struct file_lock flc;
37};
38
39
40static inline void set_version(struct dlm_plock_info *info)
41{
42 info->version[0] = DLM_PLOCK_VERSION_MAJOR;
43 info->version[1] = DLM_PLOCK_VERSION_MINOR;
44 info->version[2] = DLM_PLOCK_VERSION_PATCH;
45}
46
47static int check_version(struct dlm_plock_info *info)
48{
49 if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
50 (DLM_PLOCK_VERSION_MINOR < info->version[1])) {
51 log_print("plock device version mismatch: "
52 "kernel (%u.%u.%u), user (%u.%u.%u)",
53 DLM_PLOCK_VERSION_MAJOR,
54 DLM_PLOCK_VERSION_MINOR,
55 DLM_PLOCK_VERSION_PATCH,
56 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
74/* 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;
95 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
96 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
104int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
105 int cmd, struct file_lock *fl)
106{
107 struct dlm_ls *ls;
108 struct plock_op *op;
109 struct plock_xop *xop;
110 int rv;
111
112 ls = dlm_find_lockspace_local(lockspace);
113 if (!ls)
114 return -EINVAL;
115
116 xop = kzalloc(sizeof(*xop), GFP_NOFS);
117 if (!xop) {
118 rv = -ENOMEM;
119 goto out;
120 }
121
122 op = &xop->xop;
123 op->info.optype = DLM_PLOCK_OP_LOCK;
124 op->info.pid = fl->fl_pid;
125 op->info.ex = (fl->fl_type == F_WRLCK);
126 op->info.wait = IS_SETLKW(cmd);
127 op->info.fsid = ls->ls_global_id;
128 op->info.number = number;
129 op->info.start = fl->fl_start;
130 op->info.end = fl->fl_end;
131 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
132 /* fl_owner is lockd which doesn't distinguish
133 processes on the nfs client */
134 op->info.owner = (__u64) fl->fl_pid;
135 xop->callback = fl->fl_lmops->lm_grant;
136 locks_init_lock(&xop->flc);
137 locks_copy_lock(&xop->flc, fl);
138 xop->fl = fl;
139 xop->file = file;
140 } else {
141 op->info.owner = (__u64)(long) fl->fl_owner;
142 xop->callback = NULL;
143 }
144
145 send_op(op);
146
147 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 {
160 rv = FILE_LOCK_DEFERRED;
161 goto out;
162 }
163
164 spin_lock(&ops_lock);
165 if (!list_empty(&op->list)) {
166 log_error(ls, "dlm_posix_lock: op on list %llx",
167 (unsigned long long)number);
168 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)
176 log_error(ls, "dlm_posix_lock: vfs lock error %llx",
177 (unsigned long long)number);
178 }
179
180 kfree(xop);
181out:
182 dlm_put_lockspace(ls);
183 return rv;
184}
185EXPORT_SYMBOL_GPL(dlm_posix_lock);
186
187/* Returns failure iff a successful lock operation should be canceled */
188static int dlm_plock_callback(struct plock_op *op)
189{
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)) {
199 log_print("dlm_plock_callback: op on list %llx",
200 (unsigned long long)op->info.number);
201 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) {
212 notify(fl, NULL, op->info.rv);
213 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.
223 * As long as the fs cannot reliably cancel locks (especially
224 * in a low-memory situation), we're better off ignoring
225 * this failure than trying to recover.
226 */
227 log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
228 (unsigned long long)op->info.number, file, fl);
229 }
230
231 rv = notify(fl, NULL, 0);
232 if (rv) {
233 /* XXX: We need to cancel the fs lock here: */
234 log_print("dlm_plock_callback: lock granted after lock request "
235 "failed; dangling lock!\n");
236 goto out;
237 }
238
239out:
240 kfree(xop);
241 return rv;
242}
243
244int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
245 struct file_lock *fl)
246{
247 struct dlm_ls *ls;
248 struct plock_op *op;
249 int rv;
250
251 ls = dlm_find_lockspace_local(lockspace);
252 if (!ls)
253 return -EINVAL;
254
255 op = kzalloc(sizeof(*op), GFP_NOFS);
256 if (!op) {
257 rv = -ENOMEM;
258 goto out;
259 }
260
261 if (posix_lock_file_wait(file, fl) < 0)
262 log_error(ls, "dlm_posix_unlock: vfs unlock error %llx",
263 (unsigned long long)number);
264
265 op->info.optype = DLM_PLOCK_OP_UNLOCK;
266 op->info.pid = fl->fl_pid;
267 op->info.fsid = ls->ls_global_id;
268 op->info.number = number;
269 op->info.start = fl->fl_start;
270 op->info.end = fl->fl_end;
271 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
272 op->info.owner = (__u64) fl->fl_pid;
273 else
274 op->info.owner = (__u64)(long) fl->fl_owner;
275
276 if (fl->fl_flags & FL_CLOSE) {
277 op->info.flags |= DLM_PLOCK_FL_CLOSE;
278 send_op(op);
279 rv = 0;
280 goto out;
281 }
282
283 send_op(op);
284 wait_event(recv_wq, (op->done != 0));
285
286 spin_lock(&ops_lock);
287 if (!list_empty(&op->list)) {
288 log_error(ls, "dlm_posix_unlock: op on list %llx",
289 (unsigned long long)number);
290 list_del(&op->list);
291 }
292 spin_unlock(&ops_lock);
293
294 rv = op->info.rv;
295
296 if (rv == -ENOENT)
297 rv = 0;
298
299 kfree(op);
300out:
301 dlm_put_lockspace(ls);
302 return rv;
303}
304EXPORT_SYMBOL_GPL(dlm_posix_unlock);
305
306int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
307 struct file_lock *fl)
308{
309 struct dlm_ls *ls;
310 struct plock_op *op;
311 int rv;
312
313 ls = dlm_find_lockspace_local(lockspace);
314 if (!ls)
315 return -EINVAL;
316
317 op = kzalloc(sizeof(*op), GFP_NOFS);
318 if (!op) {
319 rv = -ENOMEM;
320 goto out;
321 }
322
323 op->info.optype = DLM_PLOCK_OP_GET;
324 op->info.pid = fl->fl_pid;
325 op->info.ex = (fl->fl_type == F_WRLCK);
326 op->info.fsid = ls->ls_global_id;
327 op->info.number = number;
328 op->info.start = fl->fl_start;
329 op->info.end = fl->fl_end;
330 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
331 op->info.owner = (__u64) fl->fl_pid;
332 else
333 op->info.owner = (__u64)(long) fl->fl_owner;
334
335 send_op(op);
336 wait_event(recv_wq, (op->done != 0));
337
338 spin_lock(&ops_lock);
339 if (!list_empty(&op->list)) {
340 log_error(ls, "dlm_posix_get: op on list %llx",
341 (unsigned long long)number);
342 list_del(&op->list);
343 }
344 spin_unlock(&ops_lock);
345
346 /* info.rv from userspace is 1 for conflict, 0 for no-conflict,
347 -ENOENT if there are no locks on the file */
348
349 rv = op->info.rv;
350
351 fl->fl_type = F_UNLCK;
352 if (rv == -ENOENT)
353 rv = 0;
354 else if (rv > 0) {
355 locks_init_lock(fl);
356 fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
357 fl->fl_flags = FL_POSIX;
358 fl->fl_pid = op->info.pid;
359 fl->fl_start = op->info.start;
360 fl->fl_end = op->info.end;
361 rv = 0;
362 }
363
364 kfree(op);
365out:
366 dlm_put_lockspace(ls);
367 return rv;
368}
369EXPORT_SYMBOL_GPL(dlm_posix_get);
370
371/* a read copies out one plock request from the send list */
372static ssize_t dev_read(struct file *file, char __user *u, size_t count,
373 loff_t *ppos)
374{
375 struct dlm_plock_info info;
376 struct plock_op *op = NULL;
377
378 if (count < sizeof(info))
379 return -EINVAL;
380
381 spin_lock(&ops_lock);
382 if (!list_empty(&send_list)) {
383 op = list_entry(send_list.next, struct plock_op, list);
384 if (op->info.flags & DLM_PLOCK_FL_CLOSE)
385 list_del(&op->list);
386 else
387 list_move(&op->list, &recv_list);
388 memcpy(&info, &op->info, sizeof(info));
389 }
390 spin_unlock(&ops_lock);
391
392 if (!op)
393 return -EAGAIN;
394
395 /* there is no need to get a reply from userspace for unlocks
396 that were generated by the vfs cleaning up for a close
397 (the process did not make an unlock call). */
398
399 if (op->info.flags & DLM_PLOCK_FL_CLOSE)
400 kfree(op);
401
402 if (copy_to_user(u, &info, sizeof(info)))
403 return -EFAULT;
404 return sizeof(info);
405}
406
407/* a write copies in one plock result that should match a plock_op
408 on the recv list */
409static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
410 loff_t *ppos)
411{
412 struct dlm_plock_info info;
413 struct plock_op *op;
414 int found = 0, do_callback = 0;
415
416 if (count != sizeof(info))
417 return -EINVAL;
418
419 if (copy_from_user(&info, u, sizeof(info)))
420 return -EFAULT;
421
422 if (check_version(&info))
423 return -EINVAL;
424
425 spin_lock(&ops_lock);
426 list_for_each_entry(op, &recv_list, list) {
427 if (op->info.fsid == info.fsid &&
428 op->info.number == info.number &&
429 op->info.owner == info.owner) {
430 struct plock_xop *xop = (struct plock_xop *)op;
431 list_del_init(&op->list);
432 memcpy(&op->info, &info, sizeof(info));
433 if (xop->callback)
434 do_callback = 1;
435 else
436 op->done = 1;
437 found = 1;
438 break;
439 }
440 }
441 spin_unlock(&ops_lock);
442
443 if (found) {
444 if (do_callback)
445 dlm_plock_callback(op);
446 else
447 wake_up(&recv_wq);
448 } else
449 log_print("dev_write no op %x %llx", info.fsid,
450 (unsigned long long)info.number);
451 return count;
452}
453
454static unsigned int dev_poll(struct file *file, poll_table *wait)
455{
456 unsigned int mask = 0;
457
458 poll_wait(file, &send_wq, wait);
459
460 spin_lock(&ops_lock);
461 if (!list_empty(&send_list))
462 mask = POLLIN | POLLRDNORM;
463 spin_unlock(&ops_lock);
464
465 return mask;
466}
467
468static const struct file_operations dev_fops = {
469 .read = dev_read,
470 .write = dev_write,
471 .poll = dev_poll,
472 .owner = THIS_MODULE,
473 .llseek = noop_llseek,
474};
475
476static struct miscdevice plock_dev_misc = {
477 .minor = MISC_DYNAMIC_MINOR,
478 .name = DLM_PLOCK_MISC_NAME,
479 .fops = &dev_fops
480};
481
482int dlm_plock_init(void)
483{
484 int rv;
485
486 spin_lock_init(&ops_lock);
487 INIT_LIST_HEAD(&send_list);
488 INIT_LIST_HEAD(&recv_list);
489 init_waitqueue_head(&send_wq);
490 init_waitqueue_head(&recv_wq);
491
492 rv = misc_register(&plock_dev_misc);
493 if (rv)
494 log_print("dlm_plock_init: misc_register failed %d", rv);
495 return rv;
496}
497
498void dlm_plock_exit(void)
499{
500 if (misc_deregister(&plock_dev_misc) < 0)
501 log_print("dlm_plock_exit: misc_deregister failed");
502}
503
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
4 */
5
6#include <linux/fs.h>
7#include <linux/miscdevice.h>
8#include <linux/poll.h>
9#include <linux/dlm.h>
10#include <linux/dlm_plock.h>
11#include <linux/slab.h>
12
13#include "dlm_internal.h"
14#include "lockspace.h"
15
16static spinlock_t ops_lock;
17static struct list_head send_list;
18static struct list_head recv_list;
19static wait_queue_head_t send_wq;
20static wait_queue_head_t recv_wq;
21
22struct plock_op {
23 struct list_head list;
24 int done;
25 struct dlm_plock_info info;
26};
27
28struct plock_xop {
29 struct plock_op xop;
30 int (*callback)(struct file_lock *fl, int result);
31 void *fl;
32 void *file;
33 struct file_lock flc;
34};
35
36
37static inline void set_version(struct dlm_plock_info *info)
38{
39 info->version[0] = DLM_PLOCK_VERSION_MAJOR;
40 info->version[1] = DLM_PLOCK_VERSION_MINOR;
41 info->version[2] = DLM_PLOCK_VERSION_PATCH;
42}
43
44static int check_version(struct dlm_plock_info *info)
45{
46 if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
47 (DLM_PLOCK_VERSION_MINOR < info->version[1])) {
48 log_print("plock device version mismatch: "
49 "kernel (%u.%u.%u), user (%u.%u.%u)",
50 DLM_PLOCK_VERSION_MAJOR,
51 DLM_PLOCK_VERSION_MINOR,
52 DLM_PLOCK_VERSION_PATCH,
53 info->version[0],
54 info->version[1],
55 info->version[2]);
56 return -EINVAL;
57 }
58 return 0;
59}
60
61static void send_op(struct plock_op *op)
62{
63 set_version(&op->info);
64 INIT_LIST_HEAD(&op->list);
65 spin_lock(&ops_lock);
66 list_add_tail(&op->list, &send_list);
67 spin_unlock(&ops_lock);
68 wake_up(&send_wq);
69}
70
71/* If a process was killed while waiting for the only plock on a file,
72 locks_remove_posix will not see any lock on the file so it won't
73 send an unlock-close to us to pass on to userspace to clean up the
74 abandoned waiter. So, we have to insert the unlock-close when the
75 lock call is interrupted. */
76
77static void do_unlock_close(struct dlm_ls *ls, u64 number,
78 struct file *file, struct file_lock *fl)
79{
80 struct plock_op *op;
81
82 op = kzalloc(sizeof(*op), GFP_NOFS);
83 if (!op)
84 return;
85
86 op->info.optype = DLM_PLOCK_OP_UNLOCK;
87 op->info.pid = fl->fl_pid;
88 op->info.fsid = ls->ls_global_id;
89 op->info.number = number;
90 op->info.start = 0;
91 op->info.end = OFFSET_MAX;
92 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
93 op->info.owner = (__u64) fl->fl_pid;
94 else
95 op->info.owner = (__u64)(long) fl->fl_owner;
96
97 op->info.flags |= DLM_PLOCK_FL_CLOSE;
98 send_op(op);
99}
100
101int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
102 int cmd, struct file_lock *fl)
103{
104 struct dlm_ls *ls;
105 struct plock_op *op;
106 struct plock_xop *xop;
107 int rv;
108
109 ls = dlm_find_lockspace_local(lockspace);
110 if (!ls)
111 return -EINVAL;
112
113 xop = kzalloc(sizeof(*xop), GFP_NOFS);
114 if (!xop) {
115 rv = -ENOMEM;
116 goto out;
117 }
118
119 op = &xop->xop;
120 op->info.optype = DLM_PLOCK_OP_LOCK;
121 op->info.pid = fl->fl_pid;
122 op->info.ex = (fl->fl_type == F_WRLCK);
123 op->info.wait = IS_SETLKW(cmd);
124 op->info.fsid = ls->ls_global_id;
125 op->info.number = number;
126 op->info.start = fl->fl_start;
127 op->info.end = fl->fl_end;
128 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
129 /* fl_owner is lockd which doesn't distinguish
130 processes on the nfs client */
131 op->info.owner = (__u64) fl->fl_pid;
132 xop->callback = fl->fl_lmops->lm_grant;
133 locks_init_lock(&xop->flc);
134 locks_copy_lock(&xop->flc, fl);
135 xop->fl = fl;
136 xop->file = file;
137 } else {
138 op->info.owner = (__u64)(long) fl->fl_owner;
139 xop->callback = NULL;
140 }
141
142 send_op(op);
143
144 if (xop->callback == NULL) {
145 rv = wait_event_interruptible(recv_wq, (op->done != 0));
146 if (rv == -ERESTARTSYS) {
147 log_debug(ls, "dlm_posix_lock: wait killed %llx",
148 (unsigned long long)number);
149 spin_lock(&ops_lock);
150 list_del(&op->list);
151 spin_unlock(&ops_lock);
152 kfree(xop);
153 do_unlock_close(ls, number, file, fl);
154 goto out;
155 }
156 } else {
157 rv = FILE_LOCK_DEFERRED;
158 goto out;
159 }
160
161 spin_lock(&ops_lock);
162 if (!list_empty(&op->list)) {
163 log_error(ls, "dlm_posix_lock: op on list %llx",
164 (unsigned long long)number);
165 list_del(&op->list);
166 }
167 spin_unlock(&ops_lock);
168
169 rv = op->info.rv;
170
171 if (!rv) {
172 if (locks_lock_file_wait(file, fl) < 0)
173 log_error(ls, "dlm_posix_lock: vfs lock error %llx",
174 (unsigned long long)number);
175 }
176
177 kfree(xop);
178out:
179 dlm_put_lockspace(ls);
180 return rv;
181}
182EXPORT_SYMBOL_GPL(dlm_posix_lock);
183
184/* Returns failure iff a successful lock operation should be canceled */
185static int dlm_plock_callback(struct plock_op *op)
186{
187 struct file *file;
188 struct file_lock *fl;
189 struct file_lock *flc;
190 int (*notify)(struct file_lock *fl, int result) = NULL;
191 struct plock_xop *xop = (struct plock_xop *)op;
192 int rv = 0;
193
194 spin_lock(&ops_lock);
195 if (!list_empty(&op->list)) {
196 log_print("dlm_plock_callback: op on list %llx",
197 (unsigned long long)op->info.number);
198 list_del(&op->list);
199 }
200 spin_unlock(&ops_lock);
201
202 /* check if the following 2 are still valid or make a copy */
203 file = xop->file;
204 flc = &xop->flc;
205 fl = xop->fl;
206 notify = xop->callback;
207
208 if (op->info.rv) {
209 notify(fl, op->info.rv);
210 goto out;
211 }
212
213 /* got fs lock; bookkeep locally as well: */
214 flc->fl_flags &= ~FL_SLEEP;
215 if (posix_lock_file(file, flc, NULL)) {
216 /*
217 * This can only happen in the case of kmalloc() failure.
218 * The filesystem's own lock is the authoritative lock,
219 * so a failure to get the lock locally is not a disaster.
220 * As long as the fs cannot reliably cancel locks (especially
221 * in a low-memory situation), we're better off ignoring
222 * this failure than trying to recover.
223 */
224 log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
225 (unsigned long long)op->info.number, file, fl);
226 }
227
228 rv = notify(fl, 0);
229 if (rv) {
230 /* XXX: We need to cancel the fs lock here: */
231 log_print("dlm_plock_callback: lock granted after lock request "
232 "failed; dangling lock!\n");
233 goto out;
234 }
235
236out:
237 kfree(xop);
238 return rv;
239}
240
241int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
242 struct file_lock *fl)
243{
244 struct dlm_ls *ls;
245 struct plock_op *op;
246 int rv;
247 unsigned char fl_flags = fl->fl_flags;
248
249 ls = dlm_find_lockspace_local(lockspace);
250 if (!ls)
251 return -EINVAL;
252
253 op = kzalloc(sizeof(*op), GFP_NOFS);
254 if (!op) {
255 rv = -ENOMEM;
256 goto out;
257 }
258
259 /* cause the vfs unlock to return ENOENT if lock is not found */
260 fl->fl_flags |= FL_EXISTS;
261
262 rv = locks_lock_file_wait(file, fl);
263 if (rv == -ENOENT) {
264 rv = 0;
265 goto out_free;
266 }
267 if (rv < 0) {
268 log_error(ls, "dlm_posix_unlock: vfs unlock error %d %llx",
269 rv, (unsigned long long)number);
270 }
271
272 op->info.optype = DLM_PLOCK_OP_UNLOCK;
273 op->info.pid = fl->fl_pid;
274 op->info.fsid = ls->ls_global_id;
275 op->info.number = number;
276 op->info.start = fl->fl_start;
277 op->info.end = fl->fl_end;
278 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
279 op->info.owner = (__u64) fl->fl_pid;
280 else
281 op->info.owner = (__u64)(long) fl->fl_owner;
282
283 if (fl->fl_flags & FL_CLOSE) {
284 op->info.flags |= DLM_PLOCK_FL_CLOSE;
285 send_op(op);
286 rv = 0;
287 goto out;
288 }
289
290 send_op(op);
291 wait_event(recv_wq, (op->done != 0));
292
293 spin_lock(&ops_lock);
294 if (!list_empty(&op->list)) {
295 log_error(ls, "dlm_posix_unlock: op on list %llx",
296 (unsigned long long)number);
297 list_del(&op->list);
298 }
299 spin_unlock(&ops_lock);
300
301 rv = op->info.rv;
302
303 if (rv == -ENOENT)
304 rv = 0;
305
306out_free:
307 kfree(op);
308out:
309 dlm_put_lockspace(ls);
310 fl->fl_flags = fl_flags;
311 return rv;
312}
313EXPORT_SYMBOL_GPL(dlm_posix_unlock);
314
315int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
316 struct file_lock *fl)
317{
318 struct dlm_ls *ls;
319 struct plock_op *op;
320 int rv;
321
322 ls = dlm_find_lockspace_local(lockspace);
323 if (!ls)
324 return -EINVAL;
325
326 op = kzalloc(sizeof(*op), GFP_NOFS);
327 if (!op) {
328 rv = -ENOMEM;
329 goto out;
330 }
331
332 op->info.optype = DLM_PLOCK_OP_GET;
333 op->info.pid = fl->fl_pid;
334 op->info.ex = (fl->fl_type == F_WRLCK);
335 op->info.fsid = ls->ls_global_id;
336 op->info.number = number;
337 op->info.start = fl->fl_start;
338 op->info.end = fl->fl_end;
339 if (fl->fl_lmops && fl->fl_lmops->lm_grant)
340 op->info.owner = (__u64) fl->fl_pid;
341 else
342 op->info.owner = (__u64)(long) fl->fl_owner;
343
344 send_op(op);
345 wait_event(recv_wq, (op->done != 0));
346
347 spin_lock(&ops_lock);
348 if (!list_empty(&op->list)) {
349 log_error(ls, "dlm_posix_get: op on list %llx",
350 (unsigned long long)number);
351 list_del(&op->list);
352 }
353 spin_unlock(&ops_lock);
354
355 /* info.rv from userspace is 1 for conflict, 0 for no-conflict,
356 -ENOENT if there are no locks on the file */
357
358 rv = op->info.rv;
359
360 fl->fl_type = F_UNLCK;
361 if (rv == -ENOENT)
362 rv = 0;
363 else if (rv > 0) {
364 locks_init_lock(fl);
365 fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
366 fl->fl_flags = FL_POSIX;
367 fl->fl_pid = -op->info.pid;
368 fl->fl_start = op->info.start;
369 fl->fl_end = op->info.end;
370 rv = 0;
371 }
372
373 kfree(op);
374out:
375 dlm_put_lockspace(ls);
376 return rv;
377}
378EXPORT_SYMBOL_GPL(dlm_posix_get);
379
380/* a read copies out one plock request from the send list */
381static ssize_t dev_read(struct file *file, char __user *u, size_t count,
382 loff_t *ppos)
383{
384 struct dlm_plock_info info;
385 struct plock_op *op = NULL;
386
387 if (count < sizeof(info))
388 return -EINVAL;
389
390 spin_lock(&ops_lock);
391 if (!list_empty(&send_list)) {
392 op = list_entry(send_list.next, struct plock_op, list);
393 if (op->info.flags & DLM_PLOCK_FL_CLOSE)
394 list_del(&op->list);
395 else
396 list_move(&op->list, &recv_list);
397 memcpy(&info, &op->info, sizeof(info));
398 }
399 spin_unlock(&ops_lock);
400
401 if (!op)
402 return -EAGAIN;
403
404 /* there is no need to get a reply from userspace for unlocks
405 that were generated by the vfs cleaning up for a close
406 (the process did not make an unlock call). */
407
408 if (op->info.flags & DLM_PLOCK_FL_CLOSE)
409 kfree(op);
410
411 if (copy_to_user(u, &info, sizeof(info)))
412 return -EFAULT;
413 return sizeof(info);
414}
415
416/* a write copies in one plock result that should match a plock_op
417 on the recv list */
418static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
419 loff_t *ppos)
420{
421 struct dlm_plock_info info;
422 struct plock_op *op;
423 int found = 0, do_callback = 0;
424
425 if (count != sizeof(info))
426 return -EINVAL;
427
428 if (copy_from_user(&info, u, sizeof(info)))
429 return -EFAULT;
430
431 if (check_version(&info))
432 return -EINVAL;
433
434 spin_lock(&ops_lock);
435 list_for_each_entry(op, &recv_list, list) {
436 if (op->info.fsid == info.fsid &&
437 op->info.number == info.number &&
438 op->info.owner == info.owner) {
439 struct plock_xop *xop = (struct plock_xop *)op;
440 list_del_init(&op->list);
441 memcpy(&op->info, &info, sizeof(info));
442 if (xop->callback)
443 do_callback = 1;
444 else
445 op->done = 1;
446 found = 1;
447 break;
448 }
449 }
450 spin_unlock(&ops_lock);
451
452 if (found) {
453 if (do_callback)
454 dlm_plock_callback(op);
455 else
456 wake_up(&recv_wq);
457 } else
458 log_print("dev_write no op %x %llx", info.fsid,
459 (unsigned long long)info.number);
460 return count;
461}
462
463static __poll_t dev_poll(struct file *file, poll_table *wait)
464{
465 __poll_t mask = 0;
466
467 poll_wait(file, &send_wq, wait);
468
469 spin_lock(&ops_lock);
470 if (!list_empty(&send_list))
471 mask = EPOLLIN | EPOLLRDNORM;
472 spin_unlock(&ops_lock);
473
474 return mask;
475}
476
477static const struct file_operations dev_fops = {
478 .read = dev_read,
479 .write = dev_write,
480 .poll = dev_poll,
481 .owner = THIS_MODULE,
482 .llseek = noop_llseek,
483};
484
485static struct miscdevice plock_dev_misc = {
486 .minor = MISC_DYNAMIC_MINOR,
487 .name = DLM_PLOCK_MISC_NAME,
488 .fops = &dev_fops
489};
490
491int dlm_plock_init(void)
492{
493 int rv;
494
495 spin_lock_init(&ops_lock);
496 INIT_LIST_HEAD(&send_list);
497 INIT_LIST_HEAD(&recv_list);
498 init_waitqueue_head(&send_wq);
499 init_waitqueue_head(&recv_wq);
500
501 rv = misc_register(&plock_dev_misc);
502 if (rv)
503 log_print("dlm_plock_init: misc_register failed %d", rv);
504 return rv;
505}
506
507void dlm_plock_exit(void)
508{
509 misc_deregister(&plock_dev_misc);
510}
511