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rnbd-srv: add comment in rnbd_srv_rdma_ev
[linux-block.git] / drivers / block / rnbd / rnbd-srv.c
CommitLineData
2de6c8de
JW		 1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * RDMA Network Block Driver
4 *
5 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8 */
9#undef pr_fmt
10#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
11
12#include <linux/module.h>
13#include <linux/blkdev.h>
14
15#include "rnbd-srv.h"
16#include "rnbd-srv-dev.h"
74e237b6 17#include "rnbd-srv-trace.h"
2de6c8de
JW		 18
19MODULE_DESCRIPTION("RDMA Network Block Device Server");
20MODULE_LICENSE("GPL");
21
22static u16 port_nr = RTRS_PORT;
23
24module_param_named(port_nr, port_nr, ushort, 0444);
25MODULE_PARM_DESC(port_nr,
26 "The port number the server is listening on (default: "
27 __stringify(RTRS_PORT)")");
28
29#define DEFAULT_DEV_SEARCH_PATH "/"
30
31static char dev_search_path[PATH_MAX] = DEFAULT_DEV_SEARCH_PATH;
32
33static int dev_search_path_set(const char *val, const struct kernel_param *kp)
34{
35 const char *p = strrchr(val, '\n') ? : val + strlen(val);
36
37 if (strlen(val) >= sizeof(dev_search_path))
38 return -EINVAL;
39
40 snprintf(dev_search_path, sizeof(dev_search_path), "%.*s",
41 (int)(p - val), val);
42
43 pr_info("dev_search_path changed to '%s'\n", dev_search_path);
44
45 return 0;
46}
47
48static struct kparam_string dev_search_path_kparam_str = {
49 .maxlen = sizeof(dev_search_path),
50 .string = dev_search_path
51};
52
53static const struct kernel_param_ops dev_search_path_ops = {
54 .set = dev_search_path_set,
55 .get = param_get_string,
56};
57
58module_param_cb(dev_search_path, &dev_search_path_ops,
59 &dev_search_path_kparam_str, 0444);
60MODULE_PARM_DESC(dev_search_path,
61 "Sets the dev_search_path. When a device is mapped this path is prepended to the device path from the map device operation. If %SESSNAME% is specified in a path, then device will be searched in a session namespace. (default: "
62 DEFAULT_DEV_SEARCH_PATH ")");
63
64static DEFINE_MUTEX(sess_lock);
65static DEFINE_SPINLOCK(dev_lock);
66
67static LIST_HEAD(sess_list);
68static LIST_HEAD(dev_list);
69
70struct rnbd_io_private {
71 struct rtrs_srv_op *id;
72 struct rnbd_srv_sess_dev *sess_dev;
73};
74
75static void rnbd_sess_dev_release(struct kref *kref)
76{
77 struct rnbd_srv_sess_dev *sess_dev;
78
79 sess_dev = container_of(kref, struct rnbd_srv_sess_dev, kref);
80 complete(sess_dev->destroy_comp);
81}
82
83static inline void rnbd_put_sess_dev(struct rnbd_srv_sess_dev *sess_dev)
84{
85 kref_put(&sess_dev->kref, rnbd_sess_dev_release);
86}
87
88void rnbd_endio(void *priv, int error)
89{
90 struct rnbd_io_private *rnbd_priv = priv;
91 struct rnbd_srv_sess_dev *sess_dev = rnbd_priv->sess_dev;
92
93 rnbd_put_sess_dev(sess_dev);
94
95 rtrs_srv_resp_rdma(rnbd_priv->id, error);
96
97 kfree(priv);
98}
99
100static struct rnbd_srv_sess_dev *
101rnbd_get_sess_dev(int dev_id, struct rnbd_srv_session *srv_sess)
102{
103 struct rnbd_srv_sess_dev *sess_dev;
104 int ret = 0;
105
106 rcu_read_lock();
107 sess_dev = xa_load(&srv_sess->index_idr, dev_id);
1e31016b 108 if (sess_dev)
2de6c8de
JW		 109 ret = kref_get_unless_zero(&sess_dev->kref);
110 rcu_read_unlock();
111
112 if (!sess_dev || !ret)
113 return ERR_PTR(-ENXIO);
114
115 return sess_dev;
116}
117
1fe0640f
CH		 118static void rnbd_dev_bi_end_io(struct bio *bio)
119{
d7b78de2 120 rnbd_endio(bio->bi_private, blk_status_to_errno(bio->bi_status));
1fe0640f
CH		 121 bio_put(bio);
122}
123
c81cba85 124static int process_rdma(struct rnbd_srv_session *srv_sess,
2de6c8de
JW		 125 struct rtrs_srv_op *id, void *data, u32 datalen,
126 const void *usr, size_t usrlen)
127{
128 const struct rnbd_msg_io *msg = usr;
129 struct rnbd_io_private *priv;
130 struct rnbd_srv_sess_dev *sess_dev;
131 u32 dev_id;
132 int err;
735d77d4
GJ		 133 struct bio *bio;
134 short prio;
2de6c8de 135
74e237b6
SP		 136 trace_process_rdma(srv_sess, msg, id, datalen, usrlen);
137
2de6c8de
JW		 138 priv = kmalloc(sizeof(*priv), GFP_KERNEL);
139 if (!priv)
140 return -ENOMEM;
141
142 dev_id = le32_to_cpu(msg->device_id);
143
144 sess_dev = rnbd_get_sess_dev(dev_id, srv_sess);
145 if (IS_ERR(sess_dev)) {
146 pr_err_ratelimited("Got I/O request on session %s for unknown device id %d\n",
147 srv_sess->sessname, dev_id);
148 err = -ENOTCONN;
149 goto err;
150 }
151
152 priv->sess_dev = sess_dev;
153 priv->id = id;
154
07888c66
CH		 155 bio = bio_alloc(sess_dev->rnbd_dev->bdev, 1,
156 rnbd_to_bio_flags(le32_to_cpu(msg->rw)), GFP_KERNEL);
1fe0640f
CH		 157 if (bio_add_page(bio, virt_to_page(data), datalen,
158 offset_in_page(data)) != datalen) {
159 rnbd_srv_err(sess_dev, "Failed to map data to bio\n");
160 err = -EINVAL;
161 goto bio_put;
2de6c8de
JW		 162 }
163
735d77d4 164 bio->bi_end_io = rnbd_dev_bi_end_io;
d7b78de2 165 bio->bi_private = priv;
735d77d4
GJ		 166 bio->bi_iter.bi_sector = le64_to_cpu(msg->sector);
167 bio->bi_iter.bi_size = le32_to_cpu(msg->bi_size);
168 prio = srv_sess->ver < RNBD_PROTO_VER_MAJOR ||
169 usrlen < sizeof(*msg) ? 0 : le16_to_cpu(msg->prio);
170 bio_set_prio(bio, prio);
735d77d4
GJ		 171
172 submit_bio(bio);
173
2de6c8de
JW		 174 return 0;
175
1fe0640f
CH		 176bio_put:
177 bio_put(bio);
2de6c8de
JW		 178 rnbd_put_sess_dev(sess_dev);
179err:
180 kfree(priv);
181 return err;
182}
183
d16b5ac8 184static void destroy_device(struct kref *kref)
2de6c8de 185{
d16b5ac8
GJ		 186 struct rnbd_srv_dev *dev = container_of(kref, struct rnbd_srv_dev, kref);
187
2de6c8de
JW		 188 WARN_ONCE(!list_empty(&dev->sess_dev_list),
189 "Device %s is being destroyed but still in use!\n",
190 dev->id);
191
192 spin_lock(&dev_lock);
193 list_del(&dev->list);
194 spin_unlock(&dev_lock);
195
196 mutex_destroy(&dev->lock);
197 if (dev->dev_kobj.state_in_sysfs)
198 /*
199 * Destroy kobj only if it was really created.
200 */
201 rnbd_srv_destroy_dev_sysfs(dev);
202 else
203 kfree(dev);
204}
205
2de6c8de
JW		 206static void rnbd_put_srv_dev(struct rnbd_srv_dev *dev)
207{
d16b5ac8 208 kref_put(&dev->kref, destroy_device);
2de6c8de
JW		 209}
210
78699805 211void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id)
2de6c8de
JW		 212{
213 DECLARE_COMPLETION_ONSTACK(dc);
214
78699805
LP		 215 if (keep_id)
216 /* free the resources for the id but don't */
217 /* allow to re-use the id itself because it */
218 /* is still used by the client */
219 xa_cmpxchg(&sess_dev->sess->index_idr, sess_dev->device_id,
220 sess_dev, NULL, 0);
221 else
222 xa_erase(&sess_dev->sess->index_idr, sess_dev->device_id);
2de6c8de 223 synchronize_rcu();
78699805 224
2de6c8de
JW		 225 sess_dev->destroy_comp = &dc;
226 rnbd_put_sess_dev(sess_dev);
227 wait_for_completion(&dc); /* wait for inflights to drop to zero */
228
229 rnbd_dev_close(sess_dev->rnbd_dev);
2de6c8de
JW		 230 mutex_lock(&sess_dev->dev->lock);
231 list_del(&sess_dev->dev_list);
232 if (sess_dev->open_flags & FMODE_WRITE)
233 sess_dev->dev->open_write_cnt--;
234 mutex_unlock(&sess_dev->dev->lock);
235
236 rnbd_put_srv_dev(sess_dev->dev);
237
238 rnbd_srv_info(sess_dev, "Device closed\n");
239 kfree(sess_dev);
240}
241
242static void destroy_sess(struct rnbd_srv_session *srv_sess)
243{
ce11bdf9
MHI		 244 struct rnbd_srv_sess_dev *sess_dev;
245 unsigned long index;
2de6c8de 246
ce11bdf9 247 if (xa_empty(&srv_sess->index_idr))
2de6c8de
JW		 248 goto out;
249
74e237b6
SP		 250 trace_destroy_sess(srv_sess);
251
2de6c8de 252 mutex_lock(&srv_sess->lock);
ce11bdf9 253 xa_for_each(&srv_sess->index_idr, index, sess_dev)
2de6c8de
JW		 254 rnbd_srv_destroy_dev_session_sysfs(sess_dev);
255 mutex_unlock(&srv_sess->lock);
256
257out:
258 xa_destroy(&srv_sess->index_idr);
2de6c8de
JW		 259
260 pr_info("RTRS Session %s disconnected\n", srv_sess->sessname);
261
262 mutex_lock(&sess_lock);
263 list_del(&srv_sess->list);
264 mutex_unlock(&sess_lock);
265
266 mutex_destroy(&srv_sess->lock);
267 kfree(srv_sess);
268}
269
f7ecac6a 270static int create_sess(struct rtrs_srv_sess *rtrs)
2de6c8de
JW		 271{
272 struct rnbd_srv_session *srv_sess;
ae4c8164 273 char pathname[NAME_MAX];
2de6c8de
JW		 274 int err;
275
ae4c8164 276 err = rtrs_srv_get_path_name(rtrs, pathname, sizeof(pathname));
2de6c8de 277 if (err) {
ae4c8164 278 pr_err("rtrs_srv_get_path_name(%s): %d\n", pathname, err);
2de6c8de
JW		 279
280 return err;
281 }
282 srv_sess = kzalloc(sizeof(*srv_sess), GFP_KERNEL);
283 if (!srv_sess)
284 return -ENOMEM;
285
286 srv_sess->queue_depth = rtrs_srv_get_queue_depth(rtrs);
2de6c8de 287 xa_init_flags(&srv_sess->index_idr, XA_FLAGS_ALLOC);
2de6c8de
JW		 288 mutex_init(&srv_sess->lock);
289 mutex_lock(&sess_lock);
290 list_add(&srv_sess->list, &sess_list);
291 mutex_unlock(&sess_lock);
292
293 srv_sess->rtrs = rtrs;
ae4c8164 294 strscpy(srv_sess->sessname, pathname, sizeof(srv_sess->sessname));
2de6c8de
JW		 295
296 rtrs_srv_set_sess_priv(rtrs, srv_sess);
297
74e237b6
SP		 298 trace_create_sess(srv_sess);
299
2de6c8de
JW		 300 return 0;
301}
302
f7ecac6a 303static int rnbd_srv_link_ev(struct rtrs_srv_sess *rtrs,
2de6c8de
JW		 304 enum rtrs_srv_link_ev ev, void *priv)
305{
306 struct rnbd_srv_session *srv_sess = priv;
307
308 switch (ev) {
309 case RTRS_SRV_LINK_EV_CONNECTED:
310 return create_sess(rtrs);
311
312 case RTRS_SRV_LINK_EV_DISCONNECTED:
313 if (WARN_ON_ONCE(!srv_sess))
314 return -EINVAL;
315
316 destroy_sess(srv_sess);
317 return 0;
318
319 default:
320 pr_warn("Received unknown RTRS session event %d from session %s\n",
321 ev, srv_sess->sessname);
322 return -EINVAL;
323 }
324}
325
c77bfa8f
GK		 326void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev,
327 struct kobj_attribute *attr)
78699805 328{
1a84e7c6
JW		 329 struct rnbd_srv_session *sess = sess_dev->sess;
330
b168e1d8
GK		 331 /* It is already started to close by client's close message. */
332 if (!mutex_trylock(&sess->lock))
333 return;
4bc14f31
MHI		 334
335 sess_dev->keep_id = true;
c77bfa8f
GK		 336 /* first remove sysfs itself to avoid deadlock */
337 sysfs_remove_file_self(&sess_dev->kobj, &attr->attr);
1a84e7c6
JW		 338 rnbd_srv_destroy_dev_session_sysfs(sess_dev);
339 mutex_unlock(&sess->lock);
78699805
LP		 340}
341
c81cba85 342static int process_msg_close(struct rnbd_srv_session *srv_sess,
2de6c8de
JW		 343 void *data, size_t datalen, const void *usr,
344 size_t usrlen)
345{
346 const struct rnbd_msg_close *close_msg = usr;
347 struct rnbd_srv_sess_dev *sess_dev;
348
74e237b6
SP		 349 trace_process_msg_close(srv_sess, close_msg);
350
2de6c8de
JW		 351 sess_dev = rnbd_get_sess_dev(le32_to_cpu(close_msg->device_id),
352 srv_sess);
353 if (IS_ERR(sess_dev))
354 return 0;
355
356 rnbd_put_sess_dev(sess_dev);
357 mutex_lock(&srv_sess->lock);
358 rnbd_srv_destroy_dev_session_sysfs(sess_dev);
359 mutex_unlock(&srv_sess->lock);
360 return 0;
361}
362
c81cba85 363static int process_msg_open(struct rnbd_srv_session *srv_sess,
2de6c8de
JW		 364 const void *msg, size_t len,
365 void *data, size_t datalen);
366
c81cba85 367static int process_msg_sess_info(struct rnbd_srv_session *srv_sess,
2de6c8de
JW		 368 const void *msg, size_t len,
369 void *data, size_t datalen);
370
c81cba85
GK		 371static int rnbd_srv_rdma_ev(void *priv,
372 struct rtrs_srv_op *id, int dir,
373 void *data, size_t datalen, const void *usr,
374 size_t usrlen)
2de6c8de
JW		 375{
376 struct rnbd_srv_session *srv_sess = priv;
377 const struct rnbd_msg_hdr *hdr = usr;
378 int ret = 0;
379 u16 type;
380
381 if (WARN_ON_ONCE(!srv_sess))
382 return -ENODEV;
383
384 type = le16_to_cpu(hdr->type);
385
386 switch (type) {
387 case RNBD_MSG_IO:
c81cba85 388 return process_rdma(srv_sess, id, data, datalen, usr, usrlen);
2de6c8de 389 case RNBD_MSG_CLOSE:
c81cba85 390 ret = process_msg_close(srv_sess, data, datalen, usr, usrlen);
2de6c8de
JW		 391 break;
392 case RNBD_MSG_OPEN:
c81cba85 393 ret = process_msg_open(srv_sess, usr, usrlen, data, datalen);
2de6c8de
JW		 394 break;
395 case RNBD_MSG_SESS_INFO:
c81cba85
GK		 396 ret = process_msg_sess_info(srv_sess, usr, usrlen, data,
397 datalen);
2de6c8de
JW		 398 break;
399 default:
400 pr_warn("Received unexpected message type %d with dir %d from session %s\n",
401 type, dir, srv_sess->sessname);
402 return -EINVAL;
403 }
404
095134fb
GJ		 405 /*
406 * Since ret is passed to rtrs to handle the failure case, we
407 * just return 0 at the end otherwise callers in rtrs would call
408 * send_io_resp_imm again to print redundant err message.
409 */
2de6c8de
JW		 410 rtrs_srv_resp_rdma(id, ret);
411 return 0;
412}
413
414static struct rnbd_srv_sess_dev
415*rnbd_sess_dev_alloc(struct rnbd_srv_session *srv_sess)
416{
417 struct rnbd_srv_sess_dev *sess_dev;
418 int error;
419
420 sess_dev = kzalloc(sizeof(*sess_dev), GFP_KERNEL);
421 if (!sess_dev)
422 return ERR_PTR(-ENOMEM);
423
424 error = xa_alloc(&srv_sess->index_idr, &sess_dev->device_id, sess_dev,
425 xa_limit_32b, GFP_NOWAIT);
426 if (error < 0) {
427 pr_warn("Allocating idr failed, err: %d\n", error);
428 kfree(sess_dev);
429 return ERR_PTR(error);
430 }
431
432 return sess_dev;
433}
434
6e880cf5 435static struct rnbd_srv_dev *rnbd_srv_init_srv_dev(struct block_device *bdev)
2de6c8de
JW		 436{
437 struct rnbd_srv_dev *dev;
438
439 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
440 if (!dev)
441 return ERR_PTR(-ENOMEM);
442
6e880cf5 443 snprintf(dev->id, sizeof(dev->id), "%pg", bdev);
2de6c8de
JW		 444 kref_init(&dev->kref);
445 INIT_LIST_HEAD(&dev->sess_dev_list);
446 mutex_init(&dev->lock);
447
448 return dev;
449}
450
451static struct rnbd_srv_dev *
452rnbd_srv_find_or_add_srv_dev(struct rnbd_srv_dev *new_dev)
453{
454 struct rnbd_srv_dev *dev;
455
456 spin_lock(&dev_lock);
457 list_for_each_entry(dev, &dev_list, list) {
458 if (!strncmp(dev->id, new_dev->id, sizeof(dev->id))) {
459 if (!kref_get_unless_zero(&dev->kref))
460 /*
461 * We lost the race, device is almost dead.
462 * Continue traversing to find a valid one.
463 */
464 continue;
465 spin_unlock(&dev_lock);
466 return dev;
467 }
468 }
469 list_add(&new_dev->list, &dev_list);
470 spin_unlock(&dev_lock);
471
472 return new_dev;
473}
474
475static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev,
476 struct rnbd_srv_session *srv_sess,
477 enum rnbd_access_mode access_mode)
478{
479 int ret = -EPERM;
480
481 mutex_lock(&srv_dev->lock);
482
483 switch (access_mode) {
484 case RNBD_ACCESS_RO:
485 ret = 0;
486 break;
487 case RNBD_ACCESS_RW:
488 if (srv_dev->open_write_cnt == 0) {
489 srv_dev->open_write_cnt++;
490 ret = 0;
491 } else {
492 pr_err("Mapping device '%s' for session %s with RW permissions failed. Device already opened as 'RW' by %d client(s), access mode %s.\n",
493 srv_dev->id, srv_sess->sessname,
494 srv_dev->open_write_cnt,
495 rnbd_access_mode_str(access_mode));
496 }
497 break;
498 case RNBD_ACCESS_MIGRATION:
499 if (srv_dev->open_write_cnt < 2) {
500 srv_dev->open_write_cnt++;
501 ret = 0;
502 } else {
503 pr_err("Mapping device '%s' for session %s with migration permissions failed. Device already opened as 'RW' by %d client(s), access mode %s.\n",
504 srv_dev->id, srv_sess->sessname,
505 srv_dev->open_write_cnt,
506 rnbd_access_mode_str(access_mode));
507 }
508 break;
509 default:
510 pr_err("Received mapping request for device '%s' on session %s with invalid access mode: %d\n",
511 srv_dev->id, srv_sess->sessname, access_mode);
512 ret = -EINVAL;
513 }
514
515 mutex_unlock(&srv_dev->lock);
516
517 return ret;
518}
519
520static struct rnbd_srv_dev *
521rnbd_srv_get_or_create_srv_dev(struct rnbd_dev *rnbd_dev,
522 struct rnbd_srv_session *srv_sess,
523 enum rnbd_access_mode access_mode)
524{
525 int ret;
526 struct rnbd_srv_dev *new_dev, *dev;
527
6e880cf5 528 new_dev = rnbd_srv_init_srv_dev(rnbd_dev->bdev);
2de6c8de
JW		 529 if (IS_ERR(new_dev))
530 return new_dev;
531
532 dev = rnbd_srv_find_or_add_srv_dev(new_dev);
533 if (dev != new_dev)
534 kfree(new_dev);
535
536 ret = rnbd_srv_check_update_open_perm(dev, srv_sess, access_mode);
537 if (ret) {
538 rnbd_put_srv_dev(dev);
539 return ERR_PTR(ret);
540 }
541
542 return dev;
543}
544
545static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
546 struct rnbd_srv_sess_dev *sess_dev)
547{
548 struct rnbd_dev *rnbd_dev = sess_dev->rnbd_dev;
549
550 rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP);
551 rsp->device_id =
552 cpu_to_le32(sess_dev->device_id);
553 rsp->nsectors =
554 cpu_to_le64(get_capacity(rnbd_dev->bdev->bd_disk));
555 rsp->logical_block_size =
556 cpu_to_le16(bdev_logical_block_size(rnbd_dev->bdev));
557 rsp->physical_block_size =
558 cpu_to_le16(bdev_physical_block_size(rnbd_dev->bdev));
559 rsp->max_segments =
560 cpu_to_le16(rnbd_dev_get_max_segs(rnbd_dev));
561 rsp->max_hw_sectors =
562 cpu_to_le32(rnbd_dev_get_max_hw_sects(rnbd_dev));
ebd04737 563 rsp->max_write_same_sectors = 0;
2de6c8de
JW		 564 rsp->max_discard_sectors =
565 cpu_to_le32(rnbd_dev_get_max_discard_sects(rnbd_dev));
566 rsp->discard_granularity =
567 cpu_to_le32(rnbd_dev_get_discard_granularity(rnbd_dev));
568 rsp->discard_alignment =
569 cpu_to_le32(rnbd_dev_get_discard_alignment(rnbd_dev));
570 rsp->secure_discard =
571 cpu_to_le16(rnbd_dev_get_secure_discard(rnbd_dev));
512c781f 572 rsp->cache_policy = 0;
08e688fd 573 if (bdev_write_cache(rnbd_dev->bdev))
512c781f 574 rsp->cache_policy |= RNBD_WRITEBACK;
a557e82e 575 if (bdev_fua(rnbd_dev->bdev))
512c781f 576 rsp->cache_policy |= RNBD_FUA;
2de6c8de
JW		 577}
578
579static struct rnbd_srv_sess_dev *
580rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess,
581 const struct rnbd_msg_open *open_msg,
582 struct rnbd_dev *rnbd_dev, fmode_t open_flags,
583 struct rnbd_srv_dev *srv_dev)
584{
585 struct rnbd_srv_sess_dev *sdev = rnbd_sess_dev_alloc(srv_sess);
586
587 if (IS_ERR(sdev))
588 return sdev;
589
590 kref_init(&sdev->kref);
591
57b93ed4 592 strscpy(sdev->pathname, open_msg->dev_name, sizeof(sdev->pathname));
2de6c8de
JW		 593
594 sdev->rnbd_dev = rnbd_dev;
595 sdev->sess = srv_sess;
596 sdev->dev = srv_dev;
597 sdev->open_flags = open_flags;
598 sdev->access_mode = open_msg->access_mode;
599
600 return sdev;
601}
602
603static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess,
604 const char *dev_name)
605{
606 char *full_path;
607 char *a, *b;
608
609 full_path = kmalloc(PATH_MAX, GFP_KERNEL);
610 if (!full_path)
611 return ERR_PTR(-ENOMEM);
612
613 /*
614 * Replace %SESSNAME% with a real session name in order to
615 * create device namespace.
616 */
617 a = strnstr(dev_search_path, "%SESSNAME%", sizeof(dev_search_path));
618 if (a) {
619 int len = a - dev_search_path;
620
621 len = snprintf(full_path, PATH_MAX, "%.*s/%s/%s", len,
622 dev_search_path, srv_sess->sessname, dev_name);
623 if (len >= PATH_MAX) {
624 pr_err("Too long path: %s, %s, %s\n",
625 dev_search_path, srv_sess->sessname, dev_name);
626 kfree(full_path);
627 return ERR_PTR(-EINVAL);
628 }
629 } else {
630 snprintf(full_path, PATH_MAX, "%s/%s",
631 dev_search_path, dev_name);
632 }
633
634 /* eliminitate duplicated slashes */
635 a = strchr(full_path, '/');
636 b = a;
637 while (*b != '\0') {
638 if (*b == '/' && *a == '/') {
639 b++;
640 } else {
641 a++;
642 *a = *b;
643 b++;
644 }
645 }
646 a++;
647 *a = '\0';
648
649 return full_path;
650}
651
c81cba85 652static int process_msg_sess_info(struct rnbd_srv_session *srv_sess,
2de6c8de
JW		 653 const void *msg, size_t len,
654 void *data, size_t datalen)
655{
656 const struct rnbd_msg_sess_info *sess_info_msg = msg;
657 struct rnbd_msg_sess_info_rsp *rsp = data;
658
659 srv_sess->ver = min_t(u8, sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
74e237b6
SP		 660
661 trace_process_msg_sess_info(srv_sess, sess_info_msg);
2de6c8de
JW		 662
663 rsp->hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO_RSP);
664 rsp->ver = srv_sess->ver;
665
666 return 0;
667}
668
669/**
670 * find_srv_sess_dev() - a dev is already opened by this name
671 * @srv_sess: the session to search.
672 * @dev_name: string containing the name of the device.
673 *
674 * Return struct rnbd_srv_sess_dev if srv_sess already opened the dev_name
675 * NULL if the session didn't open the device yet.
676 */
677static struct rnbd_srv_sess_dev *
678find_srv_sess_dev(struct rnbd_srv_session *srv_sess, const char *dev_name)
679{
680 struct rnbd_srv_sess_dev *sess_dev;
ce11bdf9 681 unsigned long index;
2de6c8de 682
ce11bdf9 683 if (xa_empty(&srv_sess->index_idr))
2de6c8de
JW		 684 return NULL;
685
ce11bdf9 686 xa_for_each(&srv_sess->index_idr, index, sess_dev)
2de6c8de
JW		 687 if (!strcmp(sess_dev->pathname, dev_name))
688 return sess_dev;
689
690 return NULL;
691}
692
c81cba85 693static int process_msg_open(struct rnbd_srv_session *srv_sess,
2de6c8de
JW		 694 const void *msg, size_t len,
695 void *data, size_t datalen)
696{
697 int ret;
698 struct rnbd_srv_dev *srv_dev;
699 struct rnbd_srv_sess_dev *srv_sess_dev;
700 const struct rnbd_msg_open *open_msg = msg;
701 fmode_t open_flags;
702 char *full_path;
703 struct rnbd_dev *rnbd_dev;
704 struct rnbd_msg_open_rsp *rsp = data;
705
74e237b6
SP		 706 trace_process_msg_open(srv_sess, open_msg);
707
2de6c8de
JW		 708 open_flags = FMODE_READ;
709 if (open_msg->access_mode != RNBD_ACCESS_RO)
710 open_flags |= FMODE_WRITE;
711
712 mutex_lock(&srv_sess->lock);
713
714 srv_sess_dev = find_srv_sess_dev(srv_sess, open_msg->dev_name);
715 if (srv_sess_dev)
716 goto fill_response;
717
718 if ((strlen(dev_search_path) + strlen(open_msg->dev_name))
719 >= PATH_MAX) {
720 pr_err("Opening device for session %s failed, device path too long. '%s/%s' is longer than PATH_MAX (%d)\n",
721 srv_sess->sessname, dev_search_path, open_msg->dev_name,
722 PATH_MAX);
723 ret = -EINVAL;
724 goto reject;
725 }
726 if (strstr(open_msg->dev_name, "..")) {
727 pr_err("Opening device for session %s failed, device path %s contains relative path ..\n",
728 srv_sess->sessname, open_msg->dev_name);
729 ret = -EINVAL;
730 goto reject;
731 }
732 full_path = rnbd_srv_get_full_path(srv_sess, open_msg->dev_name);
733 if (IS_ERR(full_path)) {
734 ret = PTR_ERR(full_path);
735 pr_err("Opening device '%s' for client %s failed, failed to get device full path, err: %d\n",
736 open_msg->dev_name, srv_sess->sessname, ret);
737 goto reject;
738 }
739
d7b78de2 740 rnbd_dev = rnbd_dev_open(full_path, open_flags);
2de6c8de
JW		 741 if (IS_ERR(rnbd_dev)) {
742 pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %ld\n",
743 full_path, srv_sess->sessname, PTR_ERR(rnbd_dev));
744 ret = PTR_ERR(rnbd_dev);
745 goto free_path;
746 }
747
748 srv_dev = rnbd_srv_get_or_create_srv_dev(rnbd_dev, srv_sess,
749 open_msg->access_mode);
750 if (IS_ERR(srv_dev)) {
751 pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %ld\n",
752 full_path, srv_sess->sessname, PTR_ERR(srv_dev));
753 ret = PTR_ERR(srv_dev);
754 goto rnbd_dev_close;
755 }
756
757 srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
758 rnbd_dev, open_flags,
759 srv_dev);
760 if (IS_ERR(srv_sess_dev)) {
761 pr_err("Opening device '%s' on session %s failed, creating sess_dev failed, err: %ld\n",
762 full_path, srv_sess->sessname, PTR_ERR(srv_sess_dev));
763 ret = PTR_ERR(srv_sess_dev);
764 goto srv_dev_put;
765 }
766
767 /* Create the srv_dev sysfs files if they haven't been created yet. The
768 * reason to delay the creation is not to create the sysfs files before
769 * we are sure the device can be opened.
770 */
771 mutex_lock(&srv_dev->lock);
772 if (!srv_dev->dev_kobj.state_in_sysfs) {
6e880cf5 773 ret = rnbd_srv_create_dev_sysfs(srv_dev, rnbd_dev->bdev);
2de6c8de
JW		 774 if (ret) {
775 mutex_unlock(&srv_dev->lock);
776 rnbd_srv_err(srv_sess_dev,
777 "Opening device failed, failed to create device sysfs files, err: %d\n",
778 ret);
779 goto free_srv_sess_dev;
780 }
781 }
782
783 ret = rnbd_srv_create_dev_session_sysfs(srv_sess_dev);
784 if (ret) {
785 mutex_unlock(&srv_dev->lock);
786 rnbd_srv_err(srv_sess_dev,
787 "Opening device failed, failed to create dev client sysfs files, err: %d\n",
788 ret);
789 goto free_srv_sess_dev;
790 }
791
792 list_add(&srv_sess_dev->dev_list, &srv_dev->sess_dev_list);
793 mutex_unlock(&srv_dev->lock);
794
2de6c8de
JW		 795 rnbd_srv_info(srv_sess_dev, "Opened device '%s'\n", srv_dev->id);
796
797 kfree(full_path);
798
799fill_response:
800 rnbd_srv_fill_msg_open_rsp(rsp, srv_sess_dev);
801 mutex_unlock(&srv_sess->lock);
802 return 0;
803
804free_srv_sess_dev:
805 xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id);
806 synchronize_rcu();
807 kfree(srv_sess_dev);
808srv_dev_put:
809 if (open_msg->access_mode != RNBD_ACCESS_RO) {
810 mutex_lock(&srv_dev->lock);
811 srv_dev->open_write_cnt--;
812 mutex_unlock(&srv_dev->lock);
813 }
814 rnbd_put_srv_dev(srv_dev);
815rnbd_dev_close:
816 rnbd_dev_close(rnbd_dev);
817free_path:
818 kfree(full_path);
819reject:
820 mutex_unlock(&srv_sess->lock);
821 return ret;
822}
823
824static struct rtrs_srv_ctx *rtrs_ctx;
825
826static struct rtrs_srv_ops rtrs_ops;
827static int __init rnbd_srv_init_module(void)
828{
829 int err;
830
831 BUILD_BUG_ON(sizeof(struct rnbd_msg_hdr) != 4);
832 BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info) != 36);
833 BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info_rsp) != 36);
834 BUILD_BUG_ON(sizeof(struct rnbd_msg_open) != 264);
835 BUILD_BUG_ON(sizeof(struct rnbd_msg_close) != 8);
836 BUILD_BUG_ON(sizeof(struct rnbd_msg_open_rsp) != 56);
837 rtrs_ops = (struct rtrs_srv_ops) {
838 .rdma_ev = rnbd_srv_rdma_ev,
839 .link_ev = rnbd_srv_link_ev,
840 };
841 rtrs_ctx = rtrs_srv_open(&rtrs_ops, port_nr);
842 if (IS_ERR(rtrs_ctx)) {
843 err = PTR_ERR(rtrs_ctx);
844 pr_err("rtrs_srv_open(), err: %d\n", err);
845 return err;
846 }
847
848 err = rnbd_srv_create_sysfs_files();
849 if (err) {
850 pr_err("rnbd_srv_create_sysfs_files(), err: %d\n", err);
851 rtrs_srv_close(rtrs_ctx);
852 return err;
853 }
854
855 return 0;
856}
857
858static void __exit rnbd_srv_cleanup_module(void)
859{
860 rtrs_srv_close(rtrs_ctx);
861 WARN_ON(!list_empty(&sess_list));
862 rnbd_srv_destroy_sysfs_files();
863}
864
865module_init(rnbd_srv_init_module);
866module_exit(rnbd_srv_cleanup_module);
Linux 6.x block layer and io_uring tree(s)