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"
17
18 MODULE_DESCRIPTION("RDMA Network Block Device Server");
19 MODULE_LICENSE("GPL");
20
21 static u16 port_nr = RTRS_PORT;
22
23 module_param_named(port_nr, port_nr, ushort, 0444);
24 MODULE_PARM_DESC(port_nr,
25 "The port number the server is listening on (default: "
26 __stringify(RTRS_PORT)")");
27
28 #define DEFAULT_DEV_SEARCH_PATH "/"
29
30 static char dev_search_path[PATH_MAX] = DEFAULT_DEV_SEARCH_PATH;
31
dev_search_path_set(const char * val,const struct kernel_param * kp)32 static int dev_search_path_set(const char *val, const struct kernel_param *kp)
33 {
34 const char *p = strrchr(val, '\n') ? : val + strlen(val);
35
36 if (strlen(val) >= sizeof(dev_search_path))
37 return -EINVAL;
38
39 snprintf(dev_search_path, sizeof(dev_search_path), "%.*s",
40 (int)(p - val), val);
41
42 pr_info("dev_search_path changed to '%s'\n", dev_search_path);
43
44 return 0;
45 }
46
47 static struct kparam_string dev_search_path_kparam_str = {
48 .maxlen = sizeof(dev_search_path),
49 .string = dev_search_path
50 };
51
52 static const struct kernel_param_ops dev_search_path_ops = {
53 .set = dev_search_path_set,
54 .get = param_get_string,
55 };
56
57 module_param_cb(dev_search_path, &dev_search_path_ops,
58 &dev_search_path_kparam_str, 0444);
59 MODULE_PARM_DESC(dev_search_path,
60 "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: "
61 DEFAULT_DEV_SEARCH_PATH ")");
62
63 static DEFINE_MUTEX(sess_lock);
64 static DEFINE_SPINLOCK(dev_lock);
65
66 static LIST_HEAD(sess_list);
67 static LIST_HEAD(dev_list);
68
69 struct rnbd_io_private {
70 struct rtrs_srv_op *id;
71 struct rnbd_srv_sess_dev *sess_dev;
72 };
73
rnbd_sess_dev_release(struct kref * kref)74 static void rnbd_sess_dev_release(struct kref *kref)
75 {
76 struct rnbd_srv_sess_dev *sess_dev;
77
78 sess_dev = container_of(kref, struct rnbd_srv_sess_dev, kref);
79 complete(sess_dev->destroy_comp);
80 }
81
rnbd_put_sess_dev(struct rnbd_srv_sess_dev * sess_dev)82 static inline void rnbd_put_sess_dev(struct rnbd_srv_sess_dev *sess_dev)
83 {
84 kref_put(&sess_dev->kref, rnbd_sess_dev_release);
85 }
86
rnbd_endio(void * priv,int error)87 void rnbd_endio(void *priv, int error)
88 {
89 struct rnbd_io_private *rnbd_priv = priv;
90 struct rnbd_srv_sess_dev *sess_dev = rnbd_priv->sess_dev;
91
92 rnbd_put_sess_dev(sess_dev);
93
94 rtrs_srv_resp_rdma(rnbd_priv->id, error);
95
96 kfree(priv);
97 }
98
99 static struct rnbd_srv_sess_dev *
rnbd_get_sess_dev(int dev_id,struct rnbd_srv_session * srv_sess)100 rnbd_get_sess_dev(int dev_id, struct rnbd_srv_session *srv_sess)
101 {
102 struct rnbd_srv_sess_dev *sess_dev;
103 int ret = 0;
104
105 rcu_read_lock();
106 sess_dev = xa_load(&srv_sess->index_idr, dev_id);
107 if (sess_dev)
108 ret = kref_get_unless_zero(&sess_dev->kref);
109 rcu_read_unlock();
110
111 if (!sess_dev || !ret)
112 return ERR_PTR(-ENXIO);
113
114 return sess_dev;
115 }
116
process_rdma(struct rnbd_srv_session * srv_sess,struct rtrs_srv_op * id,void * data,u32 datalen,const void * usr,size_t usrlen)117 static int process_rdma(struct rnbd_srv_session *srv_sess,
118 struct rtrs_srv_op *id, void *data, u32 datalen,
119 const void *usr, size_t usrlen)
120 {
121 const struct rnbd_msg_io *msg = usr;
122 struct rnbd_io_private *priv;
123 struct rnbd_srv_sess_dev *sess_dev;
124 u32 dev_id;
125 int err;
126 struct rnbd_dev_blk_io *io;
127 struct bio *bio;
128 short prio;
129
130 priv = kmalloc(sizeof(*priv), GFP_KERNEL);
131 if (!priv)
132 return -ENOMEM;
133
134 dev_id = le32_to_cpu(msg->device_id);
135
136 sess_dev = rnbd_get_sess_dev(dev_id, srv_sess);
137 if (IS_ERR(sess_dev)) {
138 pr_err_ratelimited("Got I/O request on session %s for unknown device id %d\n",
139 srv_sess->sessname, dev_id);
140 err = -ENOTCONN;
141 goto err;
142 }
143
144 priv->sess_dev = sess_dev;
145 priv->id = id;
146
147 /* Generate bio with pages pointing to the rdma buffer */
148 bio = rnbd_bio_map_kern(data, sess_dev->rnbd_dev->ibd_bio_set, datalen, GFP_KERNEL);
149 if (IS_ERR(bio)) {
150 err = PTR_ERR(bio);
151 rnbd_srv_err(sess_dev, "Failed to generate bio, err: %d\n", err);
152 goto sess_dev_put;
153 }
154
155 io = container_of(bio, struct rnbd_dev_blk_io, bio);
156 io->dev = sess_dev->rnbd_dev;
157 io->priv = priv;
158
159 bio->bi_end_io = rnbd_dev_bi_end_io;
160 bio->bi_private = io;
161 bio->bi_opf = rnbd_to_bio_flags(le32_to_cpu(msg->rw));
162 bio->bi_iter.bi_sector = le64_to_cpu(msg->sector);
163 bio->bi_iter.bi_size = le32_to_cpu(msg->bi_size);
164 prio = srv_sess->ver < RNBD_PROTO_VER_MAJOR ||
165 usrlen < sizeof(*msg) ? 0 : le16_to_cpu(msg->prio);
166 bio_set_prio(bio, prio);
167 bio_set_dev(bio, sess_dev->rnbd_dev->bdev);
168
169 submit_bio(bio);
170
171 return 0;
172
173 sess_dev_put:
174 rnbd_put_sess_dev(sess_dev);
175 err:
176 kfree(priv);
177 return err;
178 }
179
destroy_device(struct kref * kref)180 static void destroy_device(struct kref *kref)
181 {
182 struct rnbd_srv_dev *dev = container_of(kref, struct rnbd_srv_dev, kref);
183
184 WARN_ONCE(!list_empty(&dev->sess_dev_list),
185 "Device %s is being destroyed but still in use!\n",
186 dev->id);
187
188 spin_lock(&dev_lock);
189 list_del(&dev->list);
190 spin_unlock(&dev_lock);
191
192 mutex_destroy(&dev->lock);
193 if (dev->dev_kobj.state_in_sysfs)
194 /*
195 * Destroy kobj only if it was really created.
196 */
197 rnbd_srv_destroy_dev_sysfs(dev);
198 else
199 kfree(dev);
200 }
201
rnbd_put_srv_dev(struct rnbd_srv_dev * dev)202 static void rnbd_put_srv_dev(struct rnbd_srv_dev *dev)
203 {
204 kref_put(&dev->kref, destroy_device);
205 }
206
rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev * sess_dev,bool keep_id)207 void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id)
208 {
209 DECLARE_COMPLETION_ONSTACK(dc);
210
211 if (keep_id)
212 /* free the resources for the id but don't */
213 /* allow to re-use the id itself because it */
214 /* is still used by the client */
215 xa_cmpxchg(&sess_dev->sess->index_idr, sess_dev->device_id,
216 sess_dev, NULL, 0);
217 else
218 xa_erase(&sess_dev->sess->index_idr, sess_dev->device_id);
219 synchronize_rcu();
220
221 sess_dev->destroy_comp = &dc;
222 rnbd_put_sess_dev(sess_dev);
223 wait_for_completion(&dc); /* wait for inflights to drop to zero */
224
225 rnbd_dev_close(sess_dev->rnbd_dev);
226 list_del(&sess_dev->sess_list);
227 mutex_lock(&sess_dev->dev->lock);
228 list_del(&sess_dev->dev_list);
229 if (sess_dev->open_flags & FMODE_WRITE)
230 sess_dev->dev->open_write_cnt--;
231 mutex_unlock(&sess_dev->dev->lock);
232
233 rnbd_put_srv_dev(sess_dev->dev);
234
235 rnbd_srv_info(sess_dev, "Device closed\n");
236 kfree(sess_dev);
237 }
238
destroy_sess(struct rnbd_srv_session * srv_sess)239 static void destroy_sess(struct rnbd_srv_session *srv_sess)
240 {
241 struct rnbd_srv_sess_dev *sess_dev, *tmp;
242
243 if (list_empty(&srv_sess->sess_dev_list))
244 goto out;
245
246 mutex_lock(&srv_sess->lock);
247 list_for_each_entry_safe(sess_dev, tmp, &srv_sess->sess_dev_list,
248 sess_list)
249 rnbd_srv_destroy_dev_session_sysfs(sess_dev);
250 mutex_unlock(&srv_sess->lock);
251
252 out:
253 xa_destroy(&srv_sess->index_idr);
254 bioset_exit(&srv_sess->sess_bio_set);
255
256 pr_info("RTRS Session %s disconnected\n", srv_sess->sessname);
257
258 mutex_lock(&sess_lock);
259 list_del(&srv_sess->list);
260 mutex_unlock(&sess_lock);
261
262 mutex_destroy(&srv_sess->lock);
263 kfree(srv_sess);
264 }
265
create_sess(struct rtrs_srv * rtrs)266 static int create_sess(struct rtrs_srv *rtrs)
267 {
268 struct rnbd_srv_session *srv_sess;
269 char pathname[NAME_MAX];
270 int err;
271
272 err = rtrs_srv_get_path_name(rtrs, pathname, sizeof(pathname));
273 if (err) {
274 pr_err("rtrs_srv_get_path_name(%s): %d\n", pathname, err);
275
276 return err;
277 }
278 srv_sess = kzalloc(sizeof(*srv_sess), GFP_KERNEL);
279 if (!srv_sess)
280 return -ENOMEM;
281
282 srv_sess->queue_depth = rtrs_srv_get_queue_depth(rtrs);
283 err = bioset_init(&srv_sess->sess_bio_set, srv_sess->queue_depth,
284 offsetof(struct rnbd_dev_blk_io, bio),
285 BIOSET_NEED_BVECS);
286 if (err) {
287 pr_err("Allocating srv_session for path %s failed\n",
288 pathname);
289 kfree(srv_sess);
290 return err;
291 }
292
293 xa_init_flags(&srv_sess->index_idr, XA_FLAGS_ALLOC);
294 INIT_LIST_HEAD(&srv_sess->sess_dev_list);
295 mutex_init(&srv_sess->lock);
296 mutex_lock(&sess_lock);
297 list_add(&srv_sess->list, &sess_list);
298 mutex_unlock(&sess_lock);
299
300 srv_sess->rtrs = rtrs;
301 strscpy(srv_sess->sessname, pathname, sizeof(srv_sess->sessname));
302
303 rtrs_srv_set_sess_priv(rtrs, srv_sess);
304
305 return 0;
306 }
307
rnbd_srv_link_ev(struct rtrs_srv * rtrs,enum rtrs_srv_link_ev ev,void * priv)308 static int rnbd_srv_link_ev(struct rtrs_srv *rtrs,
309 enum rtrs_srv_link_ev ev, void *priv)
310 {
311 struct rnbd_srv_session *srv_sess = priv;
312
313 switch (ev) {
314 case RTRS_SRV_LINK_EV_CONNECTED:
315 return create_sess(rtrs);
316
317 case RTRS_SRV_LINK_EV_DISCONNECTED:
318 if (WARN_ON_ONCE(!srv_sess))
319 return -EINVAL;
320
321 destroy_sess(srv_sess);
322 return 0;
323
324 default:
325 pr_warn("Received unknown RTRS session event %d from session %s\n",
326 ev, srv_sess->sessname);
327 return -EINVAL;
328 }
329 }
330
rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev * sess_dev,struct kobj_attribute * attr)331 void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev,
332 struct kobj_attribute *attr)
333 {
334 struct rnbd_srv_session *sess = sess_dev->sess;
335
336 /* It is already started to close by client's close message. */
337 if (!mutex_trylock(&sess->lock))
338 return;
339
340 sess_dev->keep_id = true;
341 /* first remove sysfs itself to avoid deadlock */
342 sysfs_remove_file_self(&sess_dev->kobj, &attr->attr);
343 rnbd_srv_destroy_dev_session_sysfs(sess_dev);
344 mutex_unlock(&sess->lock);
345 }
346
process_msg_close(struct rnbd_srv_session * srv_sess,void * data,size_t datalen,const void * usr,size_t usrlen)347 static int process_msg_close(struct rnbd_srv_session *srv_sess,
348 void *data, size_t datalen, const void *usr,
349 size_t usrlen)
350 {
351 const struct rnbd_msg_close *close_msg = usr;
352 struct rnbd_srv_sess_dev *sess_dev;
353
354 sess_dev = rnbd_get_sess_dev(le32_to_cpu(close_msg->device_id),
355 srv_sess);
356 if (IS_ERR(sess_dev))
357 return 0;
358
359 rnbd_put_sess_dev(sess_dev);
360 mutex_lock(&srv_sess->lock);
361 rnbd_srv_destroy_dev_session_sysfs(sess_dev);
362 mutex_unlock(&srv_sess->lock);
363 return 0;
364 }
365
366 static int process_msg_open(struct rnbd_srv_session *srv_sess,
367 const void *msg, size_t len,
368 void *data, size_t datalen);
369
370 static int process_msg_sess_info(struct rnbd_srv_session *srv_sess,
371 const void *msg, size_t len,
372 void *data, size_t datalen);
373
rnbd_srv_rdma_ev(void * priv,struct rtrs_srv_op * id,int dir,void * data,size_t datalen,const void * usr,size_t usrlen)374 static int rnbd_srv_rdma_ev(void *priv,
375 struct rtrs_srv_op *id, int dir,
376 void *data, size_t datalen, const void *usr,
377 size_t usrlen)
378 {
379 struct rnbd_srv_session *srv_sess = priv;
380 const struct rnbd_msg_hdr *hdr = usr;
381 int ret = 0;
382 u16 type;
383
384 if (WARN_ON_ONCE(!srv_sess))
385 return -ENODEV;
386
387 type = le16_to_cpu(hdr->type);
388
389 switch (type) {
390 case RNBD_MSG_IO:
391 return process_rdma(srv_sess, id, data, datalen, usr, usrlen);
392 case RNBD_MSG_CLOSE:
393 ret = process_msg_close(srv_sess, data, datalen, usr, usrlen);
394 break;
395 case RNBD_MSG_OPEN:
396 ret = process_msg_open(srv_sess, usr, usrlen, data, datalen);
397 break;
398 case RNBD_MSG_SESS_INFO:
399 ret = process_msg_sess_info(srv_sess, usr, usrlen, data,
400 datalen);
401 break;
402 default:
403 pr_warn("Received unexpected message type %d with dir %d from session %s\n",
404 type, dir, srv_sess->sessname);
405 return -EINVAL;
406 }
407
408 rtrs_srv_resp_rdma(id, ret);
409 return 0;
410 }
411
412 static struct rnbd_srv_sess_dev
rnbd_sess_dev_alloc(struct rnbd_srv_session * srv_sess)413 *rnbd_sess_dev_alloc(struct rnbd_srv_session *srv_sess)
414 {
415 struct rnbd_srv_sess_dev *sess_dev;
416 int error;
417
418 sess_dev = kzalloc(sizeof(*sess_dev), GFP_KERNEL);
419 if (!sess_dev)
420 return ERR_PTR(-ENOMEM);
421
422 error = xa_alloc(&srv_sess->index_idr, &sess_dev->device_id, sess_dev,
423 xa_limit_32b, GFP_NOWAIT);
424 if (error < 0) {
425 pr_warn("Allocating idr failed, err: %d\n", error);
426 kfree(sess_dev);
427 return ERR_PTR(error);
428 }
429
430 return sess_dev;
431 }
432
rnbd_srv_init_srv_dev(const char * id)433 static struct rnbd_srv_dev *rnbd_srv_init_srv_dev(const char *id)
434 {
435 struct rnbd_srv_dev *dev;
436
437 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
438 if (!dev)
439 return ERR_PTR(-ENOMEM);
440
441 strscpy(dev->id, id, sizeof(dev->id));
442 kref_init(&dev->kref);
443 INIT_LIST_HEAD(&dev->sess_dev_list);
444 mutex_init(&dev->lock);
445
446 return dev;
447 }
448
449 static struct rnbd_srv_dev *
rnbd_srv_find_or_add_srv_dev(struct rnbd_srv_dev * new_dev)450 rnbd_srv_find_or_add_srv_dev(struct rnbd_srv_dev *new_dev)
451 {
452 struct rnbd_srv_dev *dev;
453
454 spin_lock(&dev_lock);
455 list_for_each_entry(dev, &dev_list, list) {
456 if (!strncmp(dev->id, new_dev->id, sizeof(dev->id))) {
457 if (!kref_get_unless_zero(&dev->kref))
458 /*
459 * We lost the race, device is almost dead.
460 * Continue traversing to find a valid one.
461 */
462 continue;
463 spin_unlock(&dev_lock);
464 return dev;
465 }
466 }
467 list_add(&new_dev->list, &dev_list);
468 spin_unlock(&dev_lock);
469
470 return new_dev;
471 }
472
rnbd_srv_check_update_open_perm(struct rnbd_srv_dev * srv_dev,struct rnbd_srv_session * srv_sess,enum rnbd_access_mode access_mode)473 static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev,
474 struct rnbd_srv_session *srv_sess,
475 enum rnbd_access_mode access_mode)
476 {
477 int ret = -EPERM;
478
479 mutex_lock(&srv_dev->lock);
480
481 switch (access_mode) {
482 case RNBD_ACCESS_RO:
483 ret = 0;
484 break;
485 case RNBD_ACCESS_RW:
486 if (srv_dev->open_write_cnt == 0) {
487 srv_dev->open_write_cnt++;
488 ret = 0;
489 } else {
490 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",
491 srv_dev->id, srv_sess->sessname,
492 srv_dev->open_write_cnt,
493 rnbd_access_mode_str(access_mode));
494 }
495 break;
496 case RNBD_ACCESS_MIGRATION:
497 if (srv_dev->open_write_cnt < 2) {
498 srv_dev->open_write_cnt++;
499 ret = 0;
500 } else {
501 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",
502 srv_dev->id, srv_sess->sessname,
503 srv_dev->open_write_cnt,
504 rnbd_access_mode_str(access_mode));
505 }
506 break;
507 default:
508 pr_err("Received mapping request for device '%s' on session %s with invalid access mode: %d\n",
509 srv_dev->id, srv_sess->sessname, access_mode);
510 ret = -EINVAL;
511 }
512
513 mutex_unlock(&srv_dev->lock);
514
515 return ret;
516 }
517
518 static struct rnbd_srv_dev *
rnbd_srv_get_or_create_srv_dev(struct rnbd_dev * rnbd_dev,struct rnbd_srv_session * srv_sess,enum rnbd_access_mode access_mode)519 rnbd_srv_get_or_create_srv_dev(struct rnbd_dev *rnbd_dev,
520 struct rnbd_srv_session *srv_sess,
521 enum rnbd_access_mode access_mode)
522 {
523 int ret;
524 struct rnbd_srv_dev *new_dev, *dev;
525
526 new_dev = rnbd_srv_init_srv_dev(rnbd_dev->name);
527 if (IS_ERR(new_dev))
528 return new_dev;
529
530 dev = rnbd_srv_find_or_add_srv_dev(new_dev);
531 if (dev != new_dev)
532 kfree(new_dev);
533
534 ret = rnbd_srv_check_update_open_perm(dev, srv_sess, access_mode);
535 if (ret) {
536 rnbd_put_srv_dev(dev);
537 return ERR_PTR(ret);
538 }
539
540 return dev;
541 }
542
rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp * rsp,struct rnbd_srv_sess_dev * sess_dev)543 static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
544 struct rnbd_srv_sess_dev *sess_dev)
545 {
546 struct rnbd_dev *rnbd_dev = sess_dev->rnbd_dev;
547 struct request_queue *q = bdev_get_queue(rnbd_dev->bdev);
548
549 rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP);
550 rsp->device_id =
551 cpu_to_le32(sess_dev->device_id);
552 rsp->nsectors =
553 cpu_to_le64(get_capacity(rnbd_dev->bdev->bd_disk));
554 rsp->logical_block_size =
555 cpu_to_le16(bdev_logical_block_size(rnbd_dev->bdev));
556 rsp->physical_block_size =
557 cpu_to_le16(bdev_physical_block_size(rnbd_dev->bdev));
558 rsp->max_segments =
559 cpu_to_le16(rnbd_dev_get_max_segs(rnbd_dev));
560 rsp->max_hw_sectors =
561 cpu_to_le32(rnbd_dev_get_max_hw_sects(rnbd_dev));
562 rsp->max_write_same_sectors =
563 cpu_to_le32(bdev_write_same(rnbd_dev->bdev));
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));
572 rsp->rotational = !blk_queue_nonrot(q);
573 rsp->cache_policy = 0;
574 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
575 rsp->cache_policy |= RNBD_WRITEBACK;
576 if (blk_queue_fua(q))
577 rsp->cache_policy |= RNBD_FUA;
578 }
579
580 static struct rnbd_srv_sess_dev *
rnbd_srv_create_set_sess_dev(struct rnbd_srv_session * srv_sess,const struct rnbd_msg_open * open_msg,struct rnbd_dev * rnbd_dev,fmode_t open_flags,struct rnbd_srv_dev * srv_dev)581 rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess,
582 const struct rnbd_msg_open *open_msg,
583 struct rnbd_dev *rnbd_dev, fmode_t open_flags,
584 struct rnbd_srv_dev *srv_dev)
585 {
586 struct rnbd_srv_sess_dev *sdev = rnbd_sess_dev_alloc(srv_sess);
587
588 if (IS_ERR(sdev))
589 return sdev;
590
591 kref_init(&sdev->kref);
592
593 strscpy(sdev->pathname, open_msg->dev_name, sizeof(sdev->pathname));
594
595 sdev->rnbd_dev = rnbd_dev;
596 sdev->sess = srv_sess;
597 sdev->dev = srv_dev;
598 sdev->open_flags = open_flags;
599 sdev->access_mode = open_msg->access_mode;
600
601 return sdev;
602 }
603
rnbd_srv_get_full_path(struct rnbd_srv_session * srv_sess,const char * dev_name)604 static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess,
605 const char *dev_name)
606 {
607 char *full_path;
608 char *a, *b;
609 int len;
610
611 full_path = kmalloc(PATH_MAX, GFP_KERNEL);
612 if (!full_path)
613 return ERR_PTR(-ENOMEM);
614
615 /*
616 * Replace %SESSNAME% with a real session name in order to
617 * create device namespace.
618 */
619 a = strnstr(dev_search_path, "%SESSNAME%", sizeof(dev_search_path));
620 if (a) {
621 len = a - dev_search_path;
622
623 len = snprintf(full_path, PATH_MAX, "%.*s/%s/%s", len,
624 dev_search_path, srv_sess->sessname, dev_name);
625 } else {
626 len = snprintf(full_path, PATH_MAX, "%s/%s",
627 dev_search_path, dev_name);
628 }
629 if (len >= PATH_MAX) {
630 pr_err("Too long path: %s, %s, %s\n",
631 dev_search_path, srv_sess->sessname, dev_name);
632 kfree(full_path);
633 return ERR_PTR(-EINVAL);
634 }
635
636 /* eliminitate duplicated slashes */
637 a = strchr(full_path, '/');
638 b = a;
639 while (*b != '\0') {
640 if (*b == '/' && *a == '/') {
641 b++;
642 } else {
643 a++;
644 *a = *b;
645 b++;
646 }
647 }
648 a++;
649 *a = '\0';
650
651 return full_path;
652 }
653
process_msg_sess_info(struct rnbd_srv_session * srv_sess,const void * msg,size_t len,void * data,size_t datalen)654 static int process_msg_sess_info(struct rnbd_srv_session *srv_sess,
655 const void *msg, size_t len,
656 void *data, size_t datalen)
657 {
658 const struct rnbd_msg_sess_info *sess_info_msg = msg;
659 struct rnbd_msg_sess_info_rsp *rsp = data;
660
661 srv_sess->ver = min_t(u8, sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
662 pr_debug("Session %s using protocol version %d (client version: %d, server version: %d)\n",
663 srv_sess->sessname, srv_sess->ver,
664 sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
665
666 rsp->hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO_RSP);
667 rsp->ver = srv_sess->ver;
668
669 return 0;
670 }
671
672 /**
673 * find_srv_sess_dev() - a dev is already opened by this name
674 * @srv_sess: the session to search.
675 * @dev_name: string containing the name of the device.
676 *
677 * Return struct rnbd_srv_sess_dev if srv_sess already opened the dev_name
678 * NULL if the session didn't open the device yet.
679 */
680 static struct rnbd_srv_sess_dev *
find_srv_sess_dev(struct rnbd_srv_session * srv_sess,const char * dev_name)681 find_srv_sess_dev(struct rnbd_srv_session *srv_sess, const char *dev_name)
682 {
683 struct rnbd_srv_sess_dev *sess_dev;
684
685 if (list_empty(&srv_sess->sess_dev_list))
686 return NULL;
687
688 list_for_each_entry(sess_dev, &srv_sess->sess_dev_list, sess_list)
689 if (!strcmp(sess_dev->pathname, dev_name))
690 return sess_dev;
691
692 return NULL;
693 }
694
process_msg_open(struct rnbd_srv_session * srv_sess,const void * msg,size_t len,void * data,size_t datalen)695 static int process_msg_open(struct rnbd_srv_session *srv_sess,
696 const void *msg, size_t len,
697 void *data, size_t datalen)
698 {
699 int ret;
700 struct rnbd_srv_dev *srv_dev;
701 struct rnbd_srv_sess_dev *srv_sess_dev;
702 const struct rnbd_msg_open *open_msg = msg;
703 fmode_t open_flags;
704 char *full_path;
705 struct rnbd_dev *rnbd_dev;
706 struct rnbd_msg_open_rsp *rsp = data;
707
708 pr_debug("Open message received: session='%s' path='%s' access_mode=%d\n",
709 srv_sess->sessname, open_msg->dev_name,
710 open_msg->access_mode);
711 open_flags = FMODE_READ;
712 if (open_msg->access_mode != RNBD_ACCESS_RO)
713 open_flags |= FMODE_WRITE;
714
715 mutex_lock(&srv_sess->lock);
716
717 srv_sess_dev = find_srv_sess_dev(srv_sess, open_msg->dev_name);
718 if (srv_sess_dev)
719 goto fill_response;
720
721 if ((strlen(dev_search_path) + strlen(open_msg->dev_name))
722 >= PATH_MAX) {
723 pr_err("Opening device for session %s failed, device path too long. '%s/%s' is longer than PATH_MAX (%d)\n",
724 srv_sess->sessname, dev_search_path, open_msg->dev_name,
725 PATH_MAX);
726 ret = -EINVAL;
727 goto reject;
728 }
729 if (strstr(open_msg->dev_name, "..")) {
730 pr_err("Opening device for session %s failed, device path %s contains relative path ..\n",
731 srv_sess->sessname, open_msg->dev_name);
732 ret = -EINVAL;
733 goto reject;
734 }
735 full_path = rnbd_srv_get_full_path(srv_sess, open_msg->dev_name);
736 if (IS_ERR(full_path)) {
737 ret = PTR_ERR(full_path);
738 pr_err("Opening device '%s' for client %s failed, failed to get device full path, err: %d\n",
739 open_msg->dev_name, srv_sess->sessname, ret);
740 goto reject;
741 }
742
743 rnbd_dev = rnbd_dev_open(full_path, open_flags,
744 &srv_sess->sess_bio_set);
745 if (IS_ERR(rnbd_dev)) {
746 pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %ld\n",
747 full_path, srv_sess->sessname, PTR_ERR(rnbd_dev));
748 ret = PTR_ERR(rnbd_dev);
749 goto free_path;
750 }
751
752 srv_dev = rnbd_srv_get_or_create_srv_dev(rnbd_dev, srv_sess,
753 open_msg->access_mode);
754 if (IS_ERR(srv_dev)) {
755 pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %ld\n",
756 full_path, srv_sess->sessname, PTR_ERR(srv_dev));
757 ret = PTR_ERR(srv_dev);
758 goto rnbd_dev_close;
759 }
760
761 srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
762 rnbd_dev, open_flags,
763 srv_dev);
764 if (IS_ERR(srv_sess_dev)) {
765 pr_err("Opening device '%s' on session %s failed, creating sess_dev failed, err: %ld\n",
766 full_path, srv_sess->sessname, PTR_ERR(srv_sess_dev));
767 ret = PTR_ERR(srv_sess_dev);
768 goto srv_dev_put;
769 }
770
771 /* Create the srv_dev sysfs files if they haven't been created yet. The
772 * reason to delay the creation is not to create the sysfs files before
773 * we are sure the device can be opened.
774 */
775 mutex_lock(&srv_dev->lock);
776 if (!srv_dev->dev_kobj.state_in_sysfs) {
777 ret = rnbd_srv_create_dev_sysfs(srv_dev, rnbd_dev->bdev,
778 rnbd_dev->name);
779 if (ret) {
780 mutex_unlock(&srv_dev->lock);
781 rnbd_srv_err(srv_sess_dev,
782 "Opening device failed, failed to create device sysfs files, err: %d\n",
783 ret);
784 goto free_srv_sess_dev;
785 }
786 }
787
788 ret = rnbd_srv_create_dev_session_sysfs(srv_sess_dev);
789 if (ret) {
790 mutex_unlock(&srv_dev->lock);
791 rnbd_srv_err(srv_sess_dev,
792 "Opening device failed, failed to create dev client sysfs files, err: %d\n",
793 ret);
794 goto free_srv_sess_dev;
795 }
796
797 list_add(&srv_sess_dev->dev_list, &srv_dev->sess_dev_list);
798 mutex_unlock(&srv_dev->lock);
799
800 list_add(&srv_sess_dev->sess_list, &srv_sess->sess_dev_list);
801
802 rnbd_srv_info(srv_sess_dev, "Opened device '%s'\n", srv_dev->id);
803
804 kfree(full_path);
805
806 fill_response:
807 rnbd_srv_fill_msg_open_rsp(rsp, srv_sess_dev);
808 mutex_unlock(&srv_sess->lock);
809 return 0;
810
811 free_srv_sess_dev:
812 xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id);
813 synchronize_rcu();
814 kfree(srv_sess_dev);
815 srv_dev_put:
816 if (open_msg->access_mode != RNBD_ACCESS_RO) {
817 mutex_lock(&srv_dev->lock);
818 srv_dev->open_write_cnt--;
819 mutex_unlock(&srv_dev->lock);
820 }
821 rnbd_put_srv_dev(srv_dev);
822 rnbd_dev_close:
823 rnbd_dev_close(rnbd_dev);
824 free_path:
825 kfree(full_path);
826 reject:
827 mutex_unlock(&srv_sess->lock);
828 return ret;
829 }
830
831 static struct rtrs_srv_ctx *rtrs_ctx;
832
833 static struct rtrs_srv_ops rtrs_ops;
rnbd_srv_init_module(void)834 static int __init rnbd_srv_init_module(void)
835 {
836 int err;
837
838 BUILD_BUG_ON(sizeof(struct rnbd_msg_hdr) != 4);
839 BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info) != 36);
840 BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info_rsp) != 36);
841 BUILD_BUG_ON(sizeof(struct rnbd_msg_open) != 264);
842 BUILD_BUG_ON(sizeof(struct rnbd_msg_close) != 8);
843 BUILD_BUG_ON(sizeof(struct rnbd_msg_open_rsp) != 56);
844 rtrs_ops = (struct rtrs_srv_ops) {
845 .rdma_ev = rnbd_srv_rdma_ev,
846 .link_ev = rnbd_srv_link_ev,
847 };
848 rtrs_ctx = rtrs_srv_open(&rtrs_ops, port_nr);
849 if (IS_ERR(rtrs_ctx)) {
850 err = PTR_ERR(rtrs_ctx);
851 pr_err("rtrs_srv_open(), err: %d\n", err);
852 return err;
853 }
854
855 err = rnbd_srv_create_sysfs_files();
856 if (err) {
857 pr_err("rnbd_srv_create_sysfs_files(), err: %d\n", err);
858 rtrs_srv_close(rtrs_ctx);
859 return err;
860 }
861
862 return 0;
863 }
864
rnbd_srv_cleanup_module(void)865 static void __exit rnbd_srv_cleanup_module(void)
866 {
867 rtrs_srv_close(rtrs_ctx);
868 WARN_ON(!list_empty(&sess_list));
869 rnbd_srv_destroy_sysfs_files();
870 }
871
872 module_init(rnbd_srv_init_module);
873 module_exit(rnbd_srv_cleanup_module);
874