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 #include <linux/fs_struct.h> 15 16 #include "rnbd-srv.h" 17 #include "rnbd-srv-trace.h" 18 19 MODULE_DESCRIPTION("RDMA Network Block Device Server"); 20 MODULE_LICENSE("GPL"); 21 22 static u16 port_nr = RTRS_PORT; 23 24 module_param_named(port_nr, port_nr, ushort, 0444); 25 MODULE_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 31 static char dev_search_path[PATH_MAX] = DEFAULT_DEV_SEARCH_PATH; 32 33 static 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 48 static struct kparam_string dev_search_path_kparam_str = { 49 .maxlen = sizeof(dev_search_path), 50 .string = dev_search_path 51 }; 52 53 static const struct kernel_param_ops dev_search_path_ops = { 54 .set = dev_search_path_set, 55 .get = param_get_string, 56 }; 57 58 module_param_cb(dev_search_path, &dev_search_path_ops, 59 &dev_search_path_kparam_str, 0444); 60 MODULE_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 64 static DEFINE_MUTEX(sess_lock); 65 static DEFINE_SPINLOCK(dev_lock); 66 67 static LIST_HEAD(sess_list); 68 static LIST_HEAD(dev_list); 69 70 struct rnbd_io_private { 71 struct rtrs_srv_op *id; 72 struct rnbd_srv_sess_dev *sess_dev; 73 }; 74 75 static 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 83 static 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 88 static struct rnbd_srv_sess_dev * 89 rnbd_get_sess_dev(int dev_id, struct rnbd_srv_session *srv_sess) 90 { 91 struct rnbd_srv_sess_dev *sess_dev; 92 int ret = 0; 93 94 rcu_read_lock(); 95 sess_dev = xa_load(&srv_sess->index_idr, dev_id); 96 if (sess_dev) 97 ret = kref_get_unless_zero(&sess_dev->kref); 98 rcu_read_unlock(); 99 100 if (!ret) 101 return ERR_PTR(-ENXIO); 102 103 return sess_dev; 104 } 105 106 static void rnbd_dev_bi_end_io(struct bio *bio) 107 { 108 struct rnbd_io_private *rnbd_priv = bio->bi_private; 109 struct rnbd_srv_sess_dev *sess_dev = rnbd_priv->sess_dev; 110 111 rnbd_put_sess_dev(sess_dev); 112 rtrs_srv_resp_rdma(rnbd_priv->id, blk_status_to_errno(bio->bi_status)); 113 114 kfree(rnbd_priv); 115 bio_put(bio); 116 } 117 118 static int process_rdma(struct rnbd_srv_session *srv_sess, 119 struct rtrs_srv_op *id, void *data, u32 datalen, 120 const void *usr, size_t usrlen) 121 { 122 const struct rnbd_msg_io *msg = usr; 123 struct rnbd_io_private *priv; 124 struct rnbd_srv_sess_dev *sess_dev; 125 u32 dev_id; 126 int err; 127 struct bio *bio; 128 short prio; 129 130 trace_process_rdma(srv_sess, msg, id, datalen, usrlen); 131 132 priv = kmalloc_obj(*priv); 133 if (!priv) 134 return -ENOMEM; 135 136 dev_id = le32_to_cpu(msg->device_id); 137 138 sess_dev = rnbd_get_sess_dev(dev_id, srv_sess); 139 if (IS_ERR(sess_dev)) { 140 pr_err_ratelimited("Got I/O request on session %s for unknown device id %d: %pe\n", 141 srv_sess->sessname, dev_id, sess_dev); 142 err = -ENOTCONN; 143 goto err; 144 } 145 146 priv->sess_dev = sess_dev; 147 priv->id = id; 148 149 bio = bio_alloc(file_bdev(sess_dev->bdev_file), !!datalen, 150 rnbd_to_bio_flags(le32_to_cpu(msg->rw)), GFP_KERNEL); 151 if (unlikely(!bio)) { 152 err = -ENOMEM; 153 goto put_sess_dev; 154 } 155 156 if (!datalen) { 157 /* 158 * For special requests like DISCARD and WRITE_ZEROES, the datalen is zero. 159 */ 160 bio->bi_iter.bi_size = le32_to_cpu(msg->bi_size); 161 } else { 162 bio_add_virt_nofail(bio, data, datalen); 163 bio->bi_opf = rnbd_to_bio_flags(le32_to_cpu(msg->rw)); 164 if (bio->bi_iter.bi_size != le32_to_cpu(msg->bi_size)) { 165 rnbd_srv_err_rl(sess_dev, 166 "Datalen mismatch: bio bi_size (%u), bi_size (%u)\n", 167 bio->bi_iter.bi_size, msg->bi_size); 168 err = -EINVAL; 169 goto bio_put; 170 } 171 } 172 173 bio->bi_end_io = rnbd_dev_bi_end_io; 174 bio->bi_private = priv; 175 bio->bi_iter.bi_sector = le64_to_cpu(msg->sector); 176 prio = srv_sess->ver < RNBD_PROTO_VER_MAJOR || 177 usrlen < sizeof(*msg) ? 0 : le16_to_cpu(msg->prio); 178 bio->bi_ioprio = prio; 179 180 submit_bio(bio); 181 182 return 0; 183 184 bio_put: 185 bio_put(bio); 186 put_sess_dev: 187 rnbd_put_sess_dev(sess_dev); 188 err: 189 kfree(priv); 190 return err; 191 } 192 193 static void destroy_device(struct kref *kref) 194 { 195 struct rnbd_srv_dev *dev = container_of(kref, struct rnbd_srv_dev, kref); 196 197 WARN_ONCE(!list_empty(&dev->sess_dev_list), 198 "Device %s is being destroyed but still in use!\n", 199 dev->name); 200 201 spin_lock(&dev_lock); 202 list_del(&dev->list); 203 spin_unlock(&dev_lock); 204 205 mutex_destroy(&dev->lock); 206 if (dev->dev_kobj.state_in_sysfs) 207 /* 208 * Destroy kobj only if it was really created. 209 */ 210 rnbd_srv_destroy_dev_sysfs(dev); 211 else 212 kfree(dev); 213 } 214 215 static void rnbd_put_srv_dev(struct rnbd_srv_dev *dev) 216 { 217 kref_put(&dev->kref, destroy_device); 218 } 219 220 void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id) 221 { 222 DECLARE_COMPLETION_ONSTACK(dc); 223 224 if (keep_id) 225 /* free the resources for the id but don't */ 226 /* allow to re-use the id itself because it */ 227 /* is still used by the client */ 228 xa_cmpxchg(&sess_dev->sess->index_idr, sess_dev->device_id, 229 sess_dev, NULL, 0); 230 else 231 xa_erase(&sess_dev->sess->index_idr, sess_dev->device_id); 232 synchronize_rcu(); 233 234 sess_dev->destroy_comp = &dc; 235 rnbd_put_sess_dev(sess_dev); 236 wait_for_completion(&dc); /* wait for inflights to drop to zero */ 237 238 fput(sess_dev->bdev_file); 239 mutex_lock(&sess_dev->dev->lock); 240 list_del(&sess_dev->dev_list); 241 if (!sess_dev->readonly) 242 sess_dev->dev->open_write_cnt--; 243 mutex_unlock(&sess_dev->dev->lock); 244 245 rnbd_put_srv_dev(sess_dev->dev); 246 247 rnbd_srv_info(sess_dev, "Device closed\n"); 248 kfree(sess_dev); 249 } 250 251 static void destroy_sess(struct rnbd_srv_session *srv_sess) 252 { 253 struct rnbd_srv_sess_dev *sess_dev; 254 unsigned long index; 255 256 if (xa_empty(&srv_sess->index_idr)) 257 goto out; 258 259 trace_destroy_sess(srv_sess); 260 261 mutex_lock(&srv_sess->lock); 262 xa_for_each(&srv_sess->index_idr, index, sess_dev) 263 rnbd_srv_destroy_dev_session_sysfs(sess_dev); 264 mutex_unlock(&srv_sess->lock); 265 266 out: 267 xa_destroy(&srv_sess->index_idr); 268 269 pr_info("RTRS Session %s disconnected\n", srv_sess->sessname); 270 271 mutex_lock(&sess_lock); 272 list_del(&srv_sess->list); 273 mutex_unlock(&sess_lock); 274 275 mutex_destroy(&srv_sess->lock); 276 kfree(srv_sess); 277 } 278 279 static int create_sess(struct rtrs_srv_sess *rtrs) 280 { 281 struct rnbd_srv_session *srv_sess; 282 char pathname[NAME_MAX]; 283 int err; 284 285 err = rtrs_srv_get_path_name(rtrs, pathname, sizeof(pathname)); 286 if (err) { 287 pr_err("rtrs_srv_get_path_name(%s): %d\n", pathname, err); 288 289 return err; 290 } 291 srv_sess = kzalloc_obj(*srv_sess); 292 if (!srv_sess) 293 return -ENOMEM; 294 295 srv_sess->queue_depth = rtrs_srv_get_queue_depth(rtrs); 296 xa_init_flags(&srv_sess->index_idr, XA_FLAGS_ALLOC); 297 mutex_init(&srv_sess->lock); 298 mutex_lock(&sess_lock); 299 list_add(&srv_sess->list, &sess_list); 300 mutex_unlock(&sess_lock); 301 302 srv_sess->rtrs = rtrs; 303 strscpy(srv_sess->sessname, pathname, sizeof(srv_sess->sessname)); 304 305 rtrs_srv_set_sess_priv(rtrs, srv_sess); 306 307 trace_create_sess(srv_sess); 308 309 return 0; 310 } 311 312 static int rnbd_srv_link_ev(struct rtrs_srv_sess *rtrs, 313 enum rtrs_srv_link_ev ev, void *priv) 314 { 315 struct rnbd_srv_session *srv_sess = priv; 316 317 switch (ev) { 318 case RTRS_SRV_LINK_EV_CONNECTED: 319 return create_sess(rtrs); 320 321 case RTRS_SRV_LINK_EV_DISCONNECTED: 322 if (WARN_ON_ONCE(!srv_sess)) 323 return -EINVAL; 324 325 destroy_sess(srv_sess); 326 return 0; 327 328 default: 329 pr_warn("Received unknown RTRS session event %d from session %s\n", 330 ev, srv_sess->sessname); 331 return -EINVAL; 332 } 333 } 334 335 void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev, 336 struct kobj_attribute *attr) 337 { 338 struct rnbd_srv_session *sess = sess_dev->sess; 339 340 /* It is already started to close by client's close message. */ 341 if (!mutex_trylock(&sess->lock)) 342 return; 343 344 sess_dev->keep_id = true; 345 /* first remove sysfs itself to avoid deadlock */ 346 sysfs_remove_file_self(&sess_dev->kobj, &attr->attr); 347 rnbd_srv_destroy_dev_session_sysfs(sess_dev); 348 mutex_unlock(&sess->lock); 349 } 350 351 static void process_msg_close(struct rnbd_srv_session *srv_sess, 352 void *data, size_t datalen, const void *usr, 353 size_t usrlen) 354 { 355 const struct rnbd_msg_close *close_msg = usr; 356 struct rnbd_srv_sess_dev *sess_dev; 357 358 trace_process_msg_close(srv_sess, close_msg); 359 360 sess_dev = rnbd_get_sess_dev(le32_to_cpu(close_msg->device_id), 361 srv_sess); 362 if (IS_ERR(sess_dev)) 363 return; 364 365 rnbd_put_sess_dev(sess_dev); 366 mutex_lock(&srv_sess->lock); 367 rnbd_srv_destroy_dev_session_sysfs(sess_dev); 368 mutex_unlock(&srv_sess->lock); 369 } 370 371 static int process_msg_open(struct rnbd_srv_session *srv_sess, 372 const void *msg, size_t len, 373 void *data, size_t datalen); 374 375 static void process_msg_sess_info(struct rnbd_srv_session *srv_sess, 376 const void *msg, size_t len, 377 void *data, size_t datalen); 378 379 static int rnbd_srv_rdma_ev(void *priv, struct rtrs_srv_op *id, 380 void *data, size_t datalen, 381 const void *usr, size_t usrlen) 382 { 383 struct rnbd_srv_session *srv_sess = priv; 384 const struct rnbd_msg_hdr *hdr = usr; 385 int ret = 0; 386 u16 type; 387 388 if (WARN_ON_ONCE(!srv_sess)) 389 return -ENODEV; 390 391 type = le16_to_cpu(hdr->type); 392 393 switch (type) { 394 case RNBD_MSG_IO: 395 return process_rdma(srv_sess, id, data, datalen, usr, usrlen); 396 case RNBD_MSG_CLOSE: 397 process_msg_close(srv_sess, data, datalen, usr, usrlen); 398 break; 399 case RNBD_MSG_OPEN: 400 ret = process_msg_open(srv_sess, usr, usrlen, data, datalen); 401 break; 402 case RNBD_MSG_SESS_INFO: 403 process_msg_sess_info(srv_sess, usr, usrlen, data, datalen); 404 break; 405 default: 406 pr_warn("Received unexpected message type %d from session %s\n", 407 type, srv_sess->sessname); 408 return -EINVAL; 409 } 410 411 /* 412 * Since ret is passed to rtrs to handle the failure case, we 413 * just return 0 at the end otherwise callers in rtrs would call 414 * send_io_resp_imm again to print redundant err message. 415 */ 416 rtrs_srv_resp_rdma(id, ret); 417 return 0; 418 } 419 420 static struct rnbd_srv_sess_dev 421 *rnbd_sess_dev_alloc(struct rnbd_srv_session *srv_sess) 422 { 423 struct rnbd_srv_sess_dev *sess_dev; 424 int error; 425 426 sess_dev = kzalloc_obj(*sess_dev); 427 if (!sess_dev) 428 return ERR_PTR(-ENOMEM); 429 430 error = xa_alloc(&srv_sess->index_idr, &sess_dev->device_id, sess_dev, 431 xa_limit_32b, GFP_NOWAIT); 432 if (error < 0) { 433 pr_warn("Allocating idr failed, err: %d\n", error); 434 kfree(sess_dev); 435 return ERR_PTR(error); 436 } 437 438 return sess_dev; 439 } 440 441 static struct rnbd_srv_dev *rnbd_srv_init_srv_dev(struct block_device *bdev) 442 { 443 struct rnbd_srv_dev *dev; 444 445 dev = kzalloc_obj(*dev); 446 if (!dev) 447 return ERR_PTR(-ENOMEM); 448 449 snprintf(dev->name, sizeof(dev->name), "%pg", bdev); 450 kref_init(&dev->kref); 451 INIT_LIST_HEAD(&dev->sess_dev_list); 452 mutex_init(&dev->lock); 453 454 return dev; 455 } 456 457 static struct rnbd_srv_dev * 458 rnbd_srv_find_or_add_srv_dev(struct rnbd_srv_dev *new_dev) 459 { 460 struct rnbd_srv_dev *dev; 461 462 spin_lock(&dev_lock); 463 list_for_each_entry(dev, &dev_list, list) { 464 if (!strncmp(dev->name, new_dev->name, sizeof(dev->name))) { 465 if (!kref_get_unless_zero(&dev->kref)) 466 /* 467 * We lost the race, device is almost dead. 468 * Continue traversing to find a valid one. 469 */ 470 continue; 471 spin_unlock(&dev_lock); 472 return dev; 473 } 474 } 475 list_add(&new_dev->list, &dev_list); 476 spin_unlock(&dev_lock); 477 478 return new_dev; 479 } 480 481 static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev, 482 struct rnbd_srv_session *srv_sess, 483 enum rnbd_access_mode access_mode) 484 { 485 int ret = 0; 486 487 mutex_lock(&srv_dev->lock); 488 489 switch (access_mode) { 490 case RNBD_ACCESS_RO: 491 break; 492 case RNBD_ACCESS_RW: 493 if (srv_dev->open_write_cnt == 0) { 494 srv_dev->open_write_cnt++; 495 } else { 496 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", 497 srv_dev->name, srv_sess->sessname, 498 srv_dev->open_write_cnt, 499 rnbd_access_modes[access_mode].str); 500 ret = -EPERM; 501 } 502 break; 503 case RNBD_ACCESS_MIGRATION: 504 if (srv_dev->open_write_cnt < 2) { 505 srv_dev->open_write_cnt++; 506 } else { 507 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", 508 srv_dev->name, srv_sess->sessname, 509 srv_dev->open_write_cnt, 510 rnbd_access_modes[access_mode].str); 511 ret = -EPERM; 512 } 513 break; 514 default: 515 pr_err("Received mapping request for device '%s' on session %s with invalid access mode: %d\n", 516 srv_dev->name, srv_sess->sessname, access_mode); 517 ret = -EINVAL; 518 } 519 520 mutex_unlock(&srv_dev->lock); 521 522 return ret; 523 } 524 525 static struct rnbd_srv_dev * 526 rnbd_srv_get_or_create_srv_dev(struct block_device *bdev, 527 struct rnbd_srv_session *srv_sess, 528 enum rnbd_access_mode access_mode) 529 { 530 int ret; 531 struct rnbd_srv_dev *new_dev, *dev; 532 533 new_dev = rnbd_srv_init_srv_dev(bdev); 534 if (IS_ERR(new_dev)) 535 return new_dev; 536 537 dev = rnbd_srv_find_or_add_srv_dev(new_dev); 538 if (dev != new_dev) 539 kfree(new_dev); 540 541 ret = rnbd_srv_check_update_open_perm(dev, srv_sess, access_mode); 542 if (ret) { 543 rnbd_put_srv_dev(dev); 544 return ERR_PTR(ret); 545 } 546 547 return dev; 548 } 549 550 static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp, 551 struct rnbd_srv_sess_dev *sess_dev) 552 { 553 struct block_device *bdev = file_bdev(sess_dev->bdev_file); 554 555 memset(rsp, 0, sizeof(*rsp)); 556 557 rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP); 558 rsp->device_id = cpu_to_le32(sess_dev->device_id); 559 rsp->nsectors = cpu_to_le64(bdev_nr_sectors(bdev)); 560 rsp->logical_block_size = cpu_to_le16(bdev_logical_block_size(bdev)); 561 rsp->physical_block_size = cpu_to_le16(bdev_physical_block_size(bdev)); 562 rsp->max_segments = cpu_to_le16(bdev_max_segments(bdev)); 563 rsp->max_hw_sectors = 564 cpu_to_le32(queue_max_hw_sectors(bdev_get_queue(bdev))); 565 rsp->max_write_zeroes_sectors = 566 cpu_to_le32(bdev_write_zeroes_sectors(bdev)); 567 rsp->max_discard_sectors = cpu_to_le32(bdev_max_discard_sectors(bdev)); 568 rsp->discard_granularity = cpu_to_le32(bdev_discard_granularity(bdev)); 569 rsp->discard_alignment = cpu_to_le32(bdev_discard_alignment(bdev)); 570 rsp->secure_discard = cpu_to_le16(bdev_max_secure_erase_sectors(bdev)); 571 rsp->cache_policy = 0; 572 if (bdev_write_cache(bdev)) 573 rsp->cache_policy |= RNBD_WRITEBACK; 574 if (bdev_fua(bdev)) 575 rsp->cache_policy |= RNBD_FUA; 576 } 577 578 static struct rnbd_srv_sess_dev * 579 rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess, 580 const struct rnbd_msg_open *open_msg, 581 struct file *bdev_file, bool readonly, 582 struct rnbd_srv_dev *srv_dev) 583 { 584 struct rnbd_srv_sess_dev *sdev = rnbd_sess_dev_alloc(srv_sess); 585 586 if (IS_ERR(sdev)) 587 return sdev; 588 589 kref_init(&sdev->kref); 590 591 strscpy(sdev->pathname, open_msg->dev_name, sizeof(sdev->pathname)); 592 593 sdev->bdev_file = bdev_file; 594 sdev->sess = srv_sess; 595 sdev->dev = srv_dev; 596 sdev->readonly = readonly; 597 sdev->access_mode = open_msg->access_mode; 598 599 return sdev; 600 } 601 602 static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess, 603 const char *dev_name) 604 { 605 char *full_path; 606 char *a, *b; 607 int len; 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 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 } else { 624 len = snprintf(full_path, PATH_MAX, "%s/%s", 625 dev_search_path, dev_name); 626 } 627 if (len >= PATH_MAX) { 628 pr_err("Too long path: %s, %s, %s\n", 629 dev_search_path, srv_sess->sessname, dev_name); 630 kfree(full_path); 631 return ERR_PTR(-EINVAL); 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 } 651 652 static void process_msg_sess_info(struct rnbd_srv_session *srv_sess, 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); 660 661 trace_process_msg_sess_info(srv_sess, sess_info_msg); 662 663 memset(rsp, 0, sizeof(*rsp)); 664 rsp->hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO_RSP); 665 rsp->ver = srv_sess->ver; 666 } 667 668 /** 669 * find_srv_sess_dev() - a dev is already opened by this name 670 * @srv_sess: the session to search. 671 * @dev_name: string containing the name of the device. 672 * 673 * Return struct rnbd_srv_sess_dev if srv_sess already opened the dev_name 674 * NULL if the session didn't open the device yet. 675 */ 676 static struct rnbd_srv_sess_dev * 677 find_srv_sess_dev(struct rnbd_srv_session *srv_sess, const char *dev_name) 678 { 679 struct rnbd_srv_sess_dev *sess_dev; 680 unsigned long index; 681 682 if (xa_empty(&srv_sess->index_idr)) 683 return NULL; 684 685 xa_for_each(&srv_sess->index_idr, index, sess_dev) 686 if (!strcmp(sess_dev->pathname, dev_name)) 687 return sess_dev; 688 689 return NULL; 690 } 691 692 static int process_msg_open(struct rnbd_srv_session *srv_sess, 693 const void *msg, size_t len, 694 void *data, size_t datalen) 695 { 696 int ret; 697 struct rnbd_srv_dev *srv_dev; 698 struct rnbd_srv_sess_dev *srv_sess_dev; 699 const struct rnbd_msg_open *open_msg = msg; 700 struct file *bdev_file; 701 blk_mode_t open_flags = BLK_OPEN_READ; 702 char *full_path; 703 struct rnbd_msg_open_rsp *rsp = data; 704 705 trace_process_msg_open(srv_sess, open_msg); 706 707 if (open_msg->access_mode != RNBD_ACCESS_RO) 708 open_flags |= BLK_OPEN_WRITE; 709 710 mutex_lock(&srv_sess->lock); 711 712 srv_sess_dev = find_srv_sess_dev(srv_sess, open_msg->dev_name); 713 if (srv_sess_dev) 714 goto fill_response; 715 716 if ((strlen(dev_search_path) + strlen(open_msg->dev_name)) 717 >= PATH_MAX) { 718 pr_err("Opening device for session %s failed, device path too long. '%s/%s' is longer than PATH_MAX (%d)\n", 719 srv_sess->sessname, dev_search_path, open_msg->dev_name, 720 PATH_MAX); 721 ret = -EINVAL; 722 goto reject; 723 } 724 if (strstr(open_msg->dev_name, "..")) { 725 pr_err("Opening device for session %s failed, device path %s contains relative path ..\n", 726 srv_sess->sessname, open_msg->dev_name); 727 ret = -EINVAL; 728 goto reject; 729 } 730 full_path = rnbd_srv_get_full_path(srv_sess, open_msg->dev_name); 731 if (IS_ERR(full_path)) { 732 ret = PTR_ERR(full_path); 733 pr_err("Opening device '%s' for client %s failed, failed to get device full path, err: %pe\n", 734 open_msg->dev_name, srv_sess->sessname, full_path); 735 goto reject; 736 } 737 738 scoped_with_init_fs() 739 bdev_file = bdev_file_open_by_path(full_path, open_flags, NULL, NULL); 740 if (IS_ERR(bdev_file)) { 741 ret = PTR_ERR(bdev_file); 742 pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %pe\n", 743 full_path, srv_sess->sessname, bdev_file); 744 goto free_path; 745 } 746 747 srv_dev = rnbd_srv_get_or_create_srv_dev(file_bdev(bdev_file), srv_sess, 748 open_msg->access_mode); 749 if (IS_ERR(srv_dev)) { 750 pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %pe\n", 751 full_path, srv_sess->sessname, srv_dev); 752 ret = PTR_ERR(srv_dev); 753 goto blkdev_put; 754 } 755 756 srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg, 757 bdev_file, 758 open_msg->access_mode == RNBD_ACCESS_RO, 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: %pe\n", 762 full_path, srv_sess->sessname, 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) { 773 ret = rnbd_srv_create_dev_sysfs(srv_dev, file_bdev(bdev_file)); 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); 794 795 rnbd_srv_info(srv_sess_dev, "Opened device '%s'\n", srv_dev->name); 796 797 kfree(full_path); 798 799 fill_response: 800 rnbd_srv_fill_msg_open_rsp(rsp, srv_sess_dev); 801 mutex_unlock(&srv_sess->lock); 802 return 0; 803 804 free_srv_sess_dev: 805 xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id); 806 synchronize_rcu(); 807 kfree(srv_sess_dev); 808 srv_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); 815 blkdev_put: 816 fput(bdev_file); 817 free_path: 818 kfree(full_path); 819 reject: 820 mutex_unlock(&srv_sess->lock); 821 return ret; 822 } 823 824 static struct rtrs_srv_ctx *rtrs_ctx; 825 826 static struct rtrs_srv_ops rtrs_ops; 827 static int __init rnbd_srv_init_module(void) 828 { 829 int err = 0; 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 pr_err("rtrs_srv_open(), err: %pe\n", rtrs_ctx); 844 return PTR_ERR(rtrs_ctx); 845 } 846 847 err = rnbd_srv_create_sysfs_files(); 848 if (err) { 849 pr_err("rnbd_srv_create_sysfs_files(), err: %d\n", err); 850 rtrs_srv_close(rtrs_ctx); 851 } 852 853 return err; 854 } 855 856 static void __exit rnbd_srv_cleanup_module(void) 857 { 858 rtrs_srv_close(rtrs_ctx); 859 WARN_ON(!list_empty(&sess_list)); 860 rnbd_srv_destroy_sysfs_files(); 861 } 862 863 module_init(rnbd_srv_init_module); 864 module_exit(rnbd_srv_cleanup_module); 865