blob: d814c51213670bb8897701e30c01dc5b78ab6af9 [file] [log] [blame]
Thomas Gleixner7336d0e2019-05-31 01:09:56 -07001// SPDX-License-Identifier: GPL-2.0-only
David Teigland869d81d2006-01-17 08:47:12 +00002/*
David Teigland24022112008-03-14 15:09:15 -05003 * Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
David Teigland869d81d2006-01-17 08:47:12 +00004 */
5
David Teigland24022112008-03-14 15:09:15 -05006#include <linux/fs.h>
Jeff Layton5970e152022-11-20 09:15:34 -05007#include <linux/filelock.h>
David Teigland869d81d2006-01-17 08:47:12 +00008#include <linux/miscdevice.h>
Al Virobd01f842006-10-19 17:23:57 -04009#include <linux/poll.h>
David Teigland24022112008-03-14 15:09:15 -050010#include <linux/dlm.h>
11#include <linux/dlm_plock.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090012#include <linux/slab.h>
David Teigland869d81d2006-01-17 08:47:12 +000013
Alexander Aring8c950062023-08-01 14:09:42 -040014#include <trace/events/dlm.h>
15
David Teigland24022112008-03-14 15:09:15 -050016#include "dlm_internal.h"
17#include "lockspace.h"
David Teigland869d81d2006-01-17 08:47:12 +000018
Alexander Aring314a5542022-04-04 16:06:36 -040019static DEFINE_SPINLOCK(ops_lock);
20static LIST_HEAD(send_list);
21static LIST_HEAD(recv_list);
22static DECLARE_WAIT_QUEUE_HEAD(send_wq);
23static DECLARE_WAIT_QUEUE_HEAD(recv_wq);
David Teigland869d81d2006-01-17 08:47:12 +000024
Alexander Aringbcbb4ba2022-04-04 16:06:32 -040025struct plock_async_data {
26 void *fl;
27 void *file;
28 struct file_lock flc;
29 int (*callback)(struct file_lock *fl, int result);
30};
31
David Teigland869d81d2006-01-17 08:47:12 +000032struct plock_op {
33 struct list_head list;
34 int done;
David Teigland24022112008-03-14 15:09:15 -050035 struct dlm_plock_info info;
Alexander Aringbcbb4ba2022-04-04 16:06:32 -040036 /* if set indicates async handling */
37 struct plock_async_data *data;
David Teigland869d81d2006-01-17 08:47:12 +000038};
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
Alexander Aringdc52cd22023-07-20 08:22:41 -040047static struct plock_op *plock_lookup_waiter(const struct dlm_plock_info *info)
48{
49 struct plock_op *op = NULL, *iter;
50
51 list_for_each_entry(iter, &recv_list, list) {
52 if (iter->info.fsid == info->fsid &&
53 iter->info.number == info->number &&
54 iter->info.owner == info->owner &&
55 iter->info.pid == info->pid &&
56 iter->info.start == info->start &&
57 iter->info.end == info->end &&
58 iter->info.ex == info->ex &&
59 iter->info.wait) {
60 op = iter;
61 break;
62 }
63 }
64
65 return op;
66}
67
David Teigland24022112008-03-14 15:09:15 -050068static int check_version(struct dlm_plock_info *info)
David Teigland869d81d2006-01-17 08:47:12 +000069{
David Teigland24022112008-03-14 15:09:15 -050070 if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
71 (DLM_PLOCK_VERSION_MINOR < info->version[1])) {
72 log_print("plock device version mismatch: "
David Teigland869d81d2006-01-17 08:47:12 +000073 "kernel (%u.%u.%u), user (%u.%u.%u)",
David Teigland24022112008-03-14 15:09:15 -050074 DLM_PLOCK_VERSION_MAJOR,
75 DLM_PLOCK_VERSION_MINOR,
76 DLM_PLOCK_VERSION_PATCH,
David Teigland869d81d2006-01-17 08:47:12 +000077 info->version[0],
78 info->version[1],
79 info->version[2]);
80 return -EINVAL;
81 }
82 return 0;
83}
84
Alexander Aringbcbb4ba2022-04-04 16:06:32 -040085static void dlm_release_plock_op(struct plock_op *op)
86{
87 kfree(op->data);
88 kfree(op);
89}
90
David Teigland869d81d2006-01-17 08:47:12 +000091static void send_op(struct plock_op *op)
92{
93 set_version(&op->info);
David Teigland869d81d2006-01-17 08:47:12 +000094 spin_lock(&ops_lock);
95 list_add_tail(&op->list, &send_list);
96 spin_unlock(&ops_lock);
97 wake_up(&send_wq);
98}
99
Alexander Aring568f9152023-07-20 08:22:40 -0400100static int do_lock_cancel(const struct dlm_plock_info *orig_info)
David Teigland901025d2011-03-02 14:20:04 -0600101{
102 struct plock_op *op;
Alexander Aring568f9152023-07-20 08:22:40 -0400103 int rv;
David Teigland901025d2011-03-02 14:20:04 -0600104
105 op = kzalloc(sizeof(*op), GFP_NOFS);
106 if (!op)
Alexander Aring568f9152023-07-20 08:22:40 -0400107 return -ENOMEM;
David Teigland901025d2011-03-02 14:20:04 -0600108
Alexander Aring568f9152023-07-20 08:22:40 -0400109 op->info = *orig_info;
110 op->info.optype = DLM_PLOCK_OP_CANCEL;
111 op->info.wait = 0;
David Teigland901025d2011-03-02 14:20:04 -0600112
David Teigland901025d2011-03-02 14:20:04 -0600113 send_op(op);
Alexander Aring568f9152023-07-20 08:22:40 -0400114 wait_event(recv_wq, (op->done != 0));
115
116 rv = op->info.rv;
117
118 dlm_release_plock_op(op);
119 return rv;
David Teigland901025d2011-03-02 14:20:04 -0600120}
121
David Teigland24022112008-03-14 15:09:15 -0500122int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
123 int cmd, struct file_lock *fl)
David Teigland869d81d2006-01-17 08:47:12 +0000124{
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400125 struct plock_async_data *op_data;
David Teigland24022112008-03-14 15:09:15 -0500126 struct dlm_ls *ls;
David Teigland869d81d2006-01-17 08:47:12 +0000127 struct plock_op *op;
128 int rv;
129
David Teigland24022112008-03-14 15:09:15 -0500130 ls = dlm_find_lockspace_local(lockspace);
131 if (!ls)
132 return -EINVAL;
133
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400134 op = kzalloc(sizeof(*op), GFP_NOFS);
135 if (!op) {
David Teigland24022112008-03-14 15:09:15 -0500136 rv = -ENOMEM;
137 goto out;
138 }
David Teigland869d81d2006-01-17 08:47:12 +0000139
David Teigland24022112008-03-14 15:09:15 -0500140 op->info.optype = DLM_PLOCK_OP_LOCK;
David Teigland3a2a9c92006-04-25 15:45:51 -0400141 op->info.pid = fl->fl_pid;
David Teigland869d81d2006-01-17 08:47:12 +0000142 op->info.ex = (fl->fl_type == F_WRLCK);
Alexander Aring6bd4a2b2023-11-13 16:24:10 -0500143 op->info.wait = !!(fl->fl_flags & FL_SLEEP);
David Teigland24022112008-03-14 15:09:15 -0500144 op->info.fsid = ls->ls_global_id;
145 op->info.number = number;
David Teigland869d81d2006-01-17 08:47:12 +0000146 op->info.start = fl->fl_start;
147 op->info.end = fl->fl_end;
Alexander Aringdbee1ad2023-11-13 16:24:09 -0500148 op->info.owner = (__u64)(long)fl->fl_owner;
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400149 /* async handling */
J. Bruce Fields8fb47a42011-07-20 20:21:59 -0400150 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400151 op_data = kzalloc(sizeof(*op_data), GFP_NOFS);
152 if (!op_data) {
153 dlm_release_plock_op(op);
154 rv = -ENOMEM;
155 goto out;
156 }
157
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400158 op_data->callback = fl->fl_lmops->lm_grant;
159 locks_init_lock(&op_data->flc);
160 locks_copy_lock(&op_data->flc, fl);
161 op_data->fl = fl;
162 op_data->file = file;
163
164 op->data = op_data;
Alexander Aringa800ba72022-04-04 16:06:33 -0400165
166 send_op(op);
167 rv = FILE_LOCK_DEFERRED;
168 goto out;
David Teigland2066b582007-12-06 09:35:25 -0600169 }
David Teigland869d81d2006-01-17 08:47:12 +0000170
171 send_op(op);
Marc Eshel586759f2006-11-14 16:37:25 -0500172
Alexander Aring0f2b1cb2023-05-19 11:21:27 -0400173 if (op->info.wait) {
Alexander Aring568f9152023-07-20 08:22:40 -0400174 rv = wait_event_interruptible(recv_wq, (op->done != 0));
Alexander Aring0f2b1cb2023-05-19 11:21:27 -0400175 if (rv == -ERESTARTSYS) {
176 spin_lock(&ops_lock);
177 /* recheck under ops_lock if we got a done != 0,
178 * if so this interrupt case should be ignored
179 */
180 if (op->done != 0) {
181 spin_unlock(&ops_lock);
182 goto do_lock_wait;
183 }
Alexander Aringb92a4e32022-06-22 14:45:09 -0400184 spin_unlock(&ops_lock);
Alexander Aringc847f4e2023-05-19 11:21:25 -0400185
Alexander Aring568f9152023-07-20 08:22:40 -0400186 rv = do_lock_cancel(&op->info);
187 switch (rv) {
188 case 0:
189 /* waiter was deleted in user space, answer will never come
190 * remove original request. The original request must be
191 * on recv_list because the answer of do_lock_cancel()
192 * synchronized it.
193 */
194 spin_lock(&ops_lock);
195 list_del(&op->list);
196 spin_unlock(&ops_lock);
197 rv = -EINTR;
198 break;
199 case -ENOENT:
200 /* cancellation wasn't successful but op should be done */
201 fallthrough;
202 default:
203 /* internal error doing cancel we need to wait */
204 goto wait;
205 }
206
Alexander Aring0f2b1cb2023-05-19 11:21:27 -0400207 log_debug(ls, "%s: wait interrupted %x %llx pid %d",
208 __func__, ls->ls_global_id,
209 (unsigned long long)number, op->info.pid);
Alexander Aring0f2b1cb2023-05-19 11:21:27 -0400210 dlm_release_plock_op(op);
211 goto out;
212 }
213 } else {
Alexander Aring568f9152023-07-20 08:22:40 -0400214wait:
Alexander Aring0f2b1cb2023-05-19 11:21:27 -0400215 wait_event(recv_wq, (op->done != 0));
David Teigland24022112008-03-14 15:09:15 -0500216 }
David Teigland869d81d2006-01-17 08:47:12 +0000217
Alexander Aringb92a4e32022-06-22 14:45:09 -0400218do_lock_wait:
219
Alexander Aringa5597902022-04-04 16:06:31 -0400220 WARN_ON(!list_empty(&op->list));
David Teigland869d81d2006-01-17 08:47:12 +0000221
222 rv = op->info.rv;
223
224 if (!rv) {
Benjamin Coddington4f656362015-10-22 13:38:14 -0400225 if (locks_lock_file_wait(file, fl) < 0)
David Teigland24022112008-03-14 15:09:15 -0500226 log_error(ls, "dlm_posix_lock: vfs lock error %llx",
227 (unsigned long long)number);
David Teigland869d81d2006-01-17 08:47:12 +0000228 }
229
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400230 dlm_release_plock_op(op);
David Teigland24022112008-03-14 15:09:15 -0500231out:
232 dlm_put_lockspace(ls);
Marc Eshel586759f2006-11-14 16:37:25 -0500233 return rv;
234}
David Teigland24022112008-03-14 15:09:15 -0500235EXPORT_SYMBOL_GPL(dlm_posix_lock);
Marc Eshel586759f2006-11-14 16:37:25 -0500236
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200237/* Returns failure iff a successful lock operation should be canceled */
David Teigland24022112008-03-14 15:09:15 -0500238static int dlm_plock_callback(struct plock_op *op)
Marc Eshel586759f2006-11-14 16:37:25 -0500239{
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400240 struct plock_async_data *op_data = op->data;
Marc Eshel586759f2006-11-14 16:37:25 -0500241 struct file *file;
242 struct file_lock *fl;
243 struct file_lock *flc;
Joe Perchesd0449b92014-08-22 10:18:42 -0400244 int (*notify)(struct file_lock *fl, int result) = NULL;
Marc Eshel586759f2006-11-14 16:37:25 -0500245 int rv = 0;
246
Alexander Aringa5597902022-04-04 16:06:31 -0400247 WARN_ON(!list_empty(&op->list));
Marc Eshel586759f2006-11-14 16:37:25 -0500248
249 /* check if the following 2 are still valid or make a copy */
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400250 file = op_data->file;
251 flc = &op_data->flc;
252 fl = op_data->fl;
253 notify = op_data->callback;
Marc Eshel586759f2006-11-14 16:37:25 -0500254
255 if (op->info.rv) {
Joe Perchesd0449b92014-08-22 10:18:42 -0400256 notify(fl, op->info.rv);
Marc Eshel586759f2006-11-14 16:37:25 -0500257 goto out;
258 }
259
260 /* got fs lock; bookkeep locally as well: */
261 flc->fl_flags &= ~FL_SLEEP;
262 if (posix_lock_file(file, flc, NULL)) {
263 /*
264 * This can only happen in the case of kmalloc() failure.
265 * The filesystem's own lock is the authoritative lock,
266 * so a failure to get the lock locally is not a disaster.
David Teigland24022112008-03-14 15:09:15 -0500267 * As long as the fs cannot reliably cancel locks (especially
Marc Eshel586759f2006-11-14 16:37:25 -0500268 * in a low-memory situation), we're better off ignoring
269 * this failure than trying to recover.
270 */
David Teigland24022112008-03-14 15:09:15 -0500271 log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
272 (unsigned long long)op->info.number, file, fl);
Marc Eshel586759f2006-11-14 16:37:25 -0500273 }
274
Joe Perchesd0449b92014-08-22 10:18:42 -0400275 rv = notify(fl, 0);
Marc Eshel586759f2006-11-14 16:37:25 -0500276 if (rv) {
277 /* XXX: We need to cancel the fs lock here: */
Alexander Aring99c58d62023-07-20 08:22:39 -0400278 log_print("%s: lock granted after lock request failed; dangling lock!",
279 __func__);
Marc Eshel586759f2006-11-14 16:37:25 -0500280 goto out;
281 }
282
283out:
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400284 dlm_release_plock_op(op);
David Teigland869d81d2006-01-17 08:47:12 +0000285 return rv;
286}
287
David Teigland24022112008-03-14 15:09:15 -0500288int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
289 struct file_lock *fl)
David Teigland869d81d2006-01-17 08:47:12 +0000290{
David Teigland24022112008-03-14 15:09:15 -0500291 struct dlm_ls *ls;
David Teigland869d81d2006-01-17 08:47:12 +0000292 struct plock_op *op;
293 int rv;
David Teigland90008312013-04-05 10:57:15 +0100294 unsigned char fl_flags = fl->fl_flags;
David Teigland869d81d2006-01-17 08:47:12 +0000295
David Teigland24022112008-03-14 15:09:15 -0500296 ls = dlm_find_lockspace_local(lockspace);
297 if (!ls)
298 return -EINVAL;
299
David Teigland573c24c2009-11-30 16:34:43 -0600300 op = kzalloc(sizeof(*op), GFP_NOFS);
David Teigland24022112008-03-14 15:09:15 -0500301 if (!op) {
302 rv = -ENOMEM;
303 goto out;
304 }
David Teigland869d81d2006-01-17 08:47:12 +0000305
David Teigland90008312013-04-05 10:57:15 +0100306 /* cause the vfs unlock to return ENOENT if lock is not found */
307 fl->fl_flags |= FL_EXISTS;
308
Benjamin Coddington4f656362015-10-22 13:38:14 -0400309 rv = locks_lock_file_wait(file, fl);
David Teigland90008312013-04-05 10:57:15 +0100310 if (rv == -ENOENT) {
311 rv = 0;
312 goto out_free;
313 }
314 if (rv < 0) {
315 log_error(ls, "dlm_posix_unlock: vfs unlock error %d %llx",
316 rv, (unsigned long long)number);
317 }
David Teigland869d81d2006-01-17 08:47:12 +0000318
David Teigland24022112008-03-14 15:09:15 -0500319 op->info.optype = DLM_PLOCK_OP_UNLOCK;
David Teigland3a2a9c92006-04-25 15:45:51 -0400320 op->info.pid = fl->fl_pid;
David Teigland24022112008-03-14 15:09:15 -0500321 op->info.fsid = ls->ls_global_id;
322 op->info.number = number;
David Teigland869d81d2006-01-17 08:47:12 +0000323 op->info.start = fl->fl_start;
324 op->info.end = fl->fl_end;
Alexander Aringdbee1ad2023-11-13 16:24:09 -0500325 op->info.owner = (__u64)(long)fl->fl_owner;
David Teigland869d81d2006-01-17 08:47:12 +0000326
David Teigland901025d2011-03-02 14:20:04 -0600327 if (fl->fl_flags & FL_CLOSE) {
328 op->info.flags |= DLM_PLOCK_FL_CLOSE;
329 send_op(op);
330 rv = 0;
331 goto out;
332 }
333
David Teigland869d81d2006-01-17 08:47:12 +0000334 send_op(op);
335 wait_event(recv_wq, (op->done != 0));
336
Alexander Aringa5597902022-04-04 16:06:31 -0400337 WARN_ON(!list_empty(&op->list));
David Teigland869d81d2006-01-17 08:47:12 +0000338
339 rv = op->info.rv;
340
Marc Eshel586759f2006-11-14 16:37:25 -0500341 if (rv == -ENOENT)
342 rv = 0;
343
David Teigland90008312013-04-05 10:57:15 +0100344out_free:
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400345 dlm_release_plock_op(op);
David Teigland24022112008-03-14 15:09:15 -0500346out:
347 dlm_put_lockspace(ls);
David Teigland90008312013-04-05 10:57:15 +0100348 fl->fl_flags = fl_flags;
David Teigland869d81d2006-01-17 08:47:12 +0000349 return rv;
350}
David Teigland24022112008-03-14 15:09:15 -0500351EXPORT_SYMBOL_GPL(dlm_posix_unlock);
David Teigland869d81d2006-01-17 08:47:12 +0000352
Alexander Aringdc52cd22023-07-20 08:22:41 -0400353/*
354 * NOTE: This implementation can only handle async lock requests as nfs
355 * do it. It cannot handle cancellation of a pending lock request sitting
356 * in wait_event(), but for now only nfs is the only user local kernel
357 * user.
358 */
359int dlm_posix_cancel(dlm_lockspace_t *lockspace, u64 number, struct file *file,
360 struct file_lock *fl)
361{
362 struct dlm_plock_info info;
363 struct plock_op *op;
364 struct dlm_ls *ls;
365 int rv;
366
367 /* this only works for async request for now and nfs is the only
368 * kernel user right now.
369 */
370 if (WARN_ON_ONCE(!fl->fl_lmops || !fl->fl_lmops->lm_grant))
371 return -EOPNOTSUPP;
372
373 ls = dlm_find_lockspace_local(lockspace);
374 if (!ls)
375 return -EINVAL;
376
377 memset(&info, 0, sizeof(info));
378 info.pid = fl->fl_pid;
379 info.ex = (fl->fl_type == F_WRLCK);
380 info.fsid = ls->ls_global_id;
381 dlm_put_lockspace(ls);
382 info.number = number;
383 info.start = fl->fl_start;
384 info.end = fl->fl_end;
Alexander Aringdbee1ad2023-11-13 16:24:09 -0500385 info.owner = (__u64)(long)fl->fl_owner;
Alexander Aringdc52cd22023-07-20 08:22:41 -0400386
387 rv = do_lock_cancel(&info);
388 switch (rv) {
389 case 0:
390 spin_lock(&ops_lock);
391 /* lock request to cancel must be on recv_list because
392 * do_lock_cancel() synchronizes it.
393 */
394 op = plock_lookup_waiter(&info);
395 if (WARN_ON_ONCE(!op)) {
Alexander Aringe717f2e2023-08-01 14:09:38 -0400396 spin_unlock(&ops_lock);
Alexander Aringdc52cd22023-07-20 08:22:41 -0400397 rv = -ENOLCK;
398 break;
399 }
400
401 list_del(&op->list);
402 spin_unlock(&ops_lock);
403 WARN_ON(op->info.optype != DLM_PLOCK_OP_LOCK);
404 op->data->callback(op->data->fl, -EINTR);
405 dlm_release_plock_op(op);
406 rv = -EINTR;
407 break;
408 case -ENOENT:
409 /* if cancel wasn't successful we probably were to late
410 * or it was a non-blocking lock request, so just unlock it.
411 */
412 rv = dlm_posix_unlock(lockspace, number, file, fl);
413 break;
414 default:
415 break;
416 }
417
418 return rv;
419}
420EXPORT_SYMBOL_GPL(dlm_posix_cancel);
421
David Teigland24022112008-03-14 15:09:15 -0500422int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
423 struct file_lock *fl)
David Teigland869d81d2006-01-17 08:47:12 +0000424{
David Teigland24022112008-03-14 15:09:15 -0500425 struct dlm_ls *ls;
David Teigland869d81d2006-01-17 08:47:12 +0000426 struct plock_op *op;
427 int rv;
428
David Teigland24022112008-03-14 15:09:15 -0500429 ls = dlm_find_lockspace_local(lockspace);
430 if (!ls)
431 return -EINVAL;
David Teigland869d81d2006-01-17 08:47:12 +0000432
David Teigland573c24c2009-11-30 16:34:43 -0600433 op = kzalloc(sizeof(*op), GFP_NOFS);
David Teigland24022112008-03-14 15:09:15 -0500434 if (!op) {
435 rv = -ENOMEM;
436 goto out;
437 }
438
439 op->info.optype = DLM_PLOCK_OP_GET;
David Teigland3a2a9c92006-04-25 15:45:51 -0400440 op->info.pid = fl->fl_pid;
David Teigland869d81d2006-01-17 08:47:12 +0000441 op->info.ex = (fl->fl_type == F_WRLCK);
David Teigland24022112008-03-14 15:09:15 -0500442 op->info.fsid = ls->ls_global_id;
443 op->info.number = number;
David Teigland869d81d2006-01-17 08:47:12 +0000444 op->info.start = fl->fl_start;
445 op->info.end = fl->fl_end;
Alexander Aringdbee1ad2023-11-13 16:24:09 -0500446 op->info.owner = (__u64)(long)fl->fl_owner;
Marc Eshel586759f2006-11-14 16:37:25 -0500447
David Teigland869d81d2006-01-17 08:47:12 +0000448 send_op(op);
449 wait_event(recv_wq, (op->done != 0));
450
Alexander Aringa5597902022-04-04 16:06:31 -0400451 WARN_ON(!list_empty(&op->list));
David Teigland869d81d2006-01-17 08:47:12 +0000452
David Teiglanda7a2ff82007-06-08 17:01:40 -0500453 /* info.rv from userspace is 1 for conflict, 0 for no-conflict,
454 -ENOENT if there are no locks on the file */
455
David Teigland869d81d2006-01-17 08:47:12 +0000456 rv = op->info.rv;
457
Marc Eshel586759f2006-11-14 16:37:25 -0500458 fl->fl_type = F_UNLCK;
459 if (rv == -ENOENT)
460 rv = 0;
David Teiglanda7a2ff82007-06-08 17:01:40 -0500461 else if (rv > 0) {
Jeff Layton20d5a392009-01-21 11:34:50 -0500462 locks_init_lock(fl);
David Teigland869d81d2006-01-17 08:47:12 +0000463 fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
Jeff Layton20d5a392009-01-21 11:34:50 -0500464 fl->fl_flags = FL_POSIX;
Alexander Aring92655fbd2023-05-19 11:21:24 -0400465 fl->fl_pid = op->info.pid;
466 if (op->info.nodeid != dlm_our_nodeid())
467 fl->fl_pid = -fl->fl_pid;
David Teigland869d81d2006-01-17 08:47:12 +0000468 fl->fl_start = op->info.start;
469 fl->fl_end = op->info.end;
David Teiglanda7a2ff82007-06-08 17:01:40 -0500470 rv = 0;
David Teigland869d81d2006-01-17 08:47:12 +0000471 }
472
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400473 dlm_release_plock_op(op);
David Teigland24022112008-03-14 15:09:15 -0500474out:
475 dlm_put_lockspace(ls);
David Teigland869d81d2006-01-17 08:47:12 +0000476 return rv;
477}
David Teigland24022112008-03-14 15:09:15 -0500478EXPORT_SYMBOL_GPL(dlm_posix_get);
David Teigland869d81d2006-01-17 08:47:12 +0000479
480/* a read copies out one plock request from the send list */
481static ssize_t dev_read(struct file *file, char __user *u, size_t count,
482 loff_t *ppos)
483{
David Teigland24022112008-03-14 15:09:15 -0500484 struct dlm_plock_info info;
David Teigland869d81d2006-01-17 08:47:12 +0000485 struct plock_op *op = NULL;
486
487 if (count < sizeof(info))
488 return -EINVAL;
489
490 spin_lock(&ops_lock);
491 if (!list_empty(&send_list)) {
Alexander Aring976a0622022-06-22 14:45:04 -0400492 op = list_first_entry(&send_list, struct plock_op, list);
David Teigland901025d2011-03-02 14:20:04 -0600493 if (op->info.flags & DLM_PLOCK_FL_CLOSE)
494 list_del(&op->list);
495 else
Alexander Aring57e2c2f2023-05-24 12:02:04 -0400496 list_move_tail(&op->list, &recv_list);
David Teigland869d81d2006-01-17 08:47:12 +0000497 memcpy(&info, &op->info, sizeof(info));
498 }
499 spin_unlock(&ops_lock);
500
501 if (!op)
502 return -EAGAIN;
503
Alexander Aring8c950062023-08-01 14:09:42 -0400504 trace_dlm_plock_read(&info);
505
David Teigland901025d2011-03-02 14:20:04 -0600506 /* there is no need to get a reply from userspace for unlocks
507 that were generated by the vfs cleaning up for a close
508 (the process did not make an unlock call). */
509
510 if (op->info.flags & DLM_PLOCK_FL_CLOSE)
Alexander Aringbcbb4ba2022-04-04 16:06:32 -0400511 dlm_release_plock_op(op);
David Teigland901025d2011-03-02 14:20:04 -0600512
David Teigland869d81d2006-01-17 08:47:12 +0000513 if (copy_to_user(u, &info, sizeof(info)))
514 return -EFAULT;
515 return sizeof(info);
516}
517
518/* a write copies in one plock result that should match a plock_op
519 on the recv list */
520static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
521 loff_t *ppos)
522{
Jakob Koscheldc1acd52022-04-06 14:05:31 -0400523 struct plock_op *op = NULL, *iter;
David Teigland24022112008-03-14 15:09:15 -0500524 struct dlm_plock_info info;
Jakob Koscheldc1acd52022-04-06 14:05:31 -0400525 int do_callback = 0;
David Teigland869d81d2006-01-17 08:47:12 +0000526
527 if (count != sizeof(info))
528 return -EINVAL;
529
530 if (copy_from_user(&info, u, sizeof(info)))
531 return -EFAULT;
532
Alexander Aring8c950062023-08-01 14:09:42 -0400533 trace_dlm_plock_write(&info);
534
David Teigland869d81d2006-01-17 08:47:12 +0000535 if (check_version(&info))
536 return -EINVAL;
537
Alexander Aring57e2c2f2023-05-24 12:02:04 -0400538 /*
539 * The results for waiting ops (SETLKW) can be returned in any
540 * order, so match all fields to find the op. The results for
541 * non-waiting ops are returned in the order that they were sent
542 * to userspace, so match the result with the first non-waiting op.
543 */
David Teigland869d81d2006-01-17 08:47:12 +0000544 spin_lock(&ops_lock);
Alexander Aring57e2c2f2023-05-24 12:02:04 -0400545 if (info.wait) {
Alexander Aringdc52cd22023-07-20 08:22:41 -0400546 op = plock_lookup_waiter(&info);
Alexander Aring57e2c2f2023-05-24 12:02:04 -0400547 } else {
548 list_for_each_entry(iter, &recv_list, list) {
Alexander Aring7c53e842023-08-24 16:51:42 -0400549 if (!iter->info.wait &&
550 iter->info.fsid == info.fsid) {
Alexander Aring57e2c2f2023-05-24 12:02:04 -0400551 op = iter;
552 break;
553 }
554 }
555 }
556
557 if (op) {
558 /* Sanity check that op and info match. */
559 if (info.wait)
560 WARN_ON(op->info.optype != DLM_PLOCK_OP_LOCK);
561 else
Alexander Aring7c53e842023-08-24 16:51:42 -0400562 WARN_ON(op->info.number != info.number ||
Alexander Aring57e2c2f2023-05-24 12:02:04 -0400563 op->info.owner != info.owner ||
564 op->info.optype != info.optype);
565
566 list_del_init(&op->list);
567 memcpy(&op->info, &info, sizeof(info));
568 if (op->data)
569 do_callback = 1;
570 else
571 op->done = 1;
David Teigland869d81d2006-01-17 08:47:12 +0000572 }
573 spin_unlock(&ops_lock);
574
Jakob Koscheldc1acd52022-04-06 14:05:31 -0400575 if (op) {
David Teiglandc78a87d2009-06-18 13:20:24 -0500576 if (do_callback)
David Teigland817d10b2008-05-13 14:28:26 -0500577 dlm_plock_callback(op);
Marc Eshel586759f2006-11-14 16:37:25 -0500578 else
579 wake_up(&recv_wq);
580 } else
Alexander Aringc847f4e2023-05-19 11:21:25 -0400581 pr_debug("%s: no op %x %llx", __func__,
582 info.fsid, (unsigned long long)info.number);
David Teigland869d81d2006-01-17 08:47:12 +0000583 return count;
584}
585
Al Viro076ccb72017-07-03 01:02:18 -0400586static __poll_t dev_poll(struct file *file, poll_table *wait)
David Teigland869d81d2006-01-17 08:47:12 +0000587{
Al Viro076ccb72017-07-03 01:02:18 -0400588 __poll_t mask = 0;
Denis Chengcee23c72007-07-25 17:53:58 +0800589
David Teigland869d81d2006-01-17 08:47:12 +0000590 poll_wait(file, &send_wq, wait);
591
592 spin_lock(&ops_lock);
Denis Chengcee23c72007-07-25 17:53:58 +0800593 if (!list_empty(&send_list))
Linus Torvaldsa9a08842018-02-11 14:34:03 -0800594 mask = EPOLLIN | EPOLLRDNORM;
David Teigland869d81d2006-01-17 08:47:12 +0000595 spin_unlock(&ops_lock);
Denis Chengcee23c72007-07-25 17:53:58 +0800596
597 return mask;
David Teigland869d81d2006-01-17 08:47:12 +0000598}
599
Arjan van de Ven00977a52007-02-12 00:55:34 -0800600static const struct file_operations dev_fops = {
David Teigland869d81d2006-01-17 08:47:12 +0000601 .read = dev_read,
602 .write = dev_write,
603 .poll = dev_poll,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200604 .owner = THIS_MODULE,
605 .llseek = noop_llseek,
David Teigland869d81d2006-01-17 08:47:12 +0000606};
607
608static struct miscdevice plock_dev_misc = {
609 .minor = MISC_DYNAMIC_MINOR,
David Teigland24022112008-03-14 15:09:15 -0500610 .name = DLM_PLOCK_MISC_NAME,
David Teigland869d81d2006-01-17 08:47:12 +0000611 .fops = &dev_fops
612};
613
David Teigland24022112008-03-14 15:09:15 -0500614int dlm_plock_init(void)
David Teigland869d81d2006-01-17 08:47:12 +0000615{
616 int rv;
617
David Teigland869d81d2006-01-17 08:47:12 +0000618 rv = misc_register(&plock_dev_misc);
619 if (rv)
David Teigland24022112008-03-14 15:09:15 -0500620 log_print("dlm_plock_init: misc_register failed %d", rv);
David Teigland869d81d2006-01-17 08:47:12 +0000621 return rv;
622}
623
David Teigland24022112008-03-14 15:09:15 -0500624void dlm_plock_exit(void)
David Teigland869d81d2006-01-17 08:47:12 +0000625{
Greg Kroah-Hartmanf368ed62015-07-30 15:59:57 -0700626 misc_deregister(&plock_dev_misc);
Alexander Aring67b5da92023-08-01 14:09:41 -0400627 WARN_ON(!list_empty(&send_list));
628 WARN_ON(!list_empty(&recv_list));
David Teigland869d81d2006-01-17 08:47:12 +0000629}
630