drivers/block/rnbd/rnbd-srv.c

   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
  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
  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
  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
  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 *
 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 (likely(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
 117 static int process_rdma(struct rtrs_srv *sess,
 118                         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 rnbd_dev_blk_io *io;
 128         struct bio *bio;
 129         short prio;
 130
 131         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
 132         if (!priv)
 133                 return -ENOMEM;
 134
 135         dev_id = le32_to_cpu(msg->device_id);
 136
 137         sess_dev = rnbd_get_sess_dev(dev_id, srv_sess);
 138         if (IS_ERR(sess_dev)) {
 139                 pr_err_ratelimited("Got I/O request on session %s for unknown device id %d\n",
 140                                    srv_sess->sessname, dev_id);
 141                 err = -ENOTCONN;
 142                 goto err;
 143         }
 144
 145         priv->sess_dev = sess_dev;
 146         priv->id = id;
 147
 148         /* Generate bio with pages pointing to the rdma buffer */
 149         bio = rnbd_bio_map_kern(data, sess_dev->rnbd_dev->ibd_bio_set, datalen, GFP_KERNEL);
 150         if (IS_ERR(bio)) {
 151                 err = PTR_ERR(bio);
 152                 rnbd_srv_err(sess_dev, "Failed to generate bio, err: %d\n", err);
 153                 goto sess_dev_put;
 154         }
 155
 156         io = container_of(bio, struct rnbd_dev_blk_io, bio);
 157         io->dev = sess_dev->rnbd_dev;
 158         io->priv = priv;
 159
 160         bio->bi_end_io = rnbd_dev_bi_end_io;
 161         bio->bi_private = io;
 162         bio->bi_opf = rnbd_to_bio_flags(le32_to_cpu(msg->rw));
 163         bio->bi_iter.bi_sector = le64_to_cpu(msg->sector);
 164         bio->bi_iter.bi_size = le32_to_cpu(msg->bi_size);
 165         prio = srv_sess->ver < RNBD_PROTO_VER_MAJOR ||
 166                usrlen < sizeof(*msg) ? 0 : le16_to_cpu(msg->prio);
 167         bio_set_prio(bio, prio);
 168         bio_set_dev(bio, sess_dev->rnbd_dev->bdev);
 169
 170         submit_bio(bio);
 171
 172         return 0;
 173
 174 sess_dev_put:
 175         rnbd_put_sess_dev(sess_dev);
 176 err:
 177         kfree(priv);
 178         return err;
 179 }
 180
 181 static void destroy_device(struct rnbd_srv_dev *dev)
 182 {
 183         WARN_ONCE(!list_empty(&dev->sess_dev_list),
 184                   "Device %s is being destroyed but still in use!\n",
 185                   dev->id);
 186
 187         spin_lock(&dev_lock);
 188         list_del(&dev->list);
 189         spin_unlock(&dev_lock);
 190
 191         mutex_destroy(&dev->lock);
 192         if (dev->dev_kobj.state_in_sysfs)
 193                 /*
 194                  * Destroy kobj only if it was really created.
 195                  */
 196                 rnbd_srv_destroy_dev_sysfs(dev);
 197         else
 198                 kfree(dev);
 199 }
 200
 201 static void destroy_device_cb(struct kref *kref)
 202 {
 203         struct rnbd_srv_dev *dev;
 204
 205         dev = container_of(kref, struct rnbd_srv_dev, kref);
 206
 207         destroy_device(dev);
 208 }
 209
 210 static void rnbd_put_srv_dev(struct rnbd_srv_dev *dev)
 211 {
 212         kref_put(&dev->kref, destroy_device_cb);
 213 }
 214
 215 void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev, bool keep_id)
 216 {
 217         DECLARE_COMPLETION_ONSTACK(dc);
 218
 219         if (keep_id)
 220                 /* free the resources for the id but don't  */
 221                 /* allow to re-use the id itself because it */
 222                 /* is still used by the client              */
 223                 xa_cmpxchg(&sess_dev->sess->index_idr, sess_dev->device_id,
 224                            sess_dev, NULL, 0);
 225         else
 226                 xa_erase(&sess_dev->sess->index_idr, sess_dev->device_id);
 227         synchronize_rcu();
 228
 229         sess_dev->destroy_comp = &dc;
 230         rnbd_put_sess_dev(sess_dev);
 231         wait_for_completion(&dc); /* wait for inflights to drop to zero */
 232
 233         rnbd_dev_close(sess_dev->rnbd_dev);
 234         list_del(&sess_dev->sess_list);
 235         mutex_lock(&sess_dev->dev->lock);
 236         list_del(&sess_dev->dev_list);
 237         if (sess_dev->open_flags & FMODE_WRITE)
 238                 sess_dev->dev->open_write_cnt--;
 239         mutex_unlock(&sess_dev->dev->lock);
 240
 241         rnbd_put_srv_dev(sess_dev->dev);
 242
 243         rnbd_srv_info(sess_dev, "Device closed\n");
 244         kfree(sess_dev);
 245 }
 246
 247 static void destroy_sess(struct rnbd_srv_session *srv_sess)
 248 {
 249         struct rnbd_srv_sess_dev *sess_dev, *tmp;
 250
 251         if (list_empty(&srv_sess->sess_dev_list))
 252                 goto out;
 253
 254         mutex_lock(&srv_sess->lock);
 255         list_for_each_entry_safe(sess_dev, tmp, &srv_sess->sess_dev_list,
 256                                  sess_list)
 257                 rnbd_srv_destroy_dev_session_sysfs(sess_dev);
 258         mutex_unlock(&srv_sess->lock);
 259
 260 out:
 261         xa_destroy(&srv_sess->index_idr);
 262         bioset_exit(&srv_sess->sess_bio_set);
 263
 264         pr_info("RTRS Session %s disconnected\n", srv_sess->sessname);
 265
 266         mutex_lock(&sess_lock);
 267         list_del(&srv_sess->list);
 268         mutex_unlock(&sess_lock);
 269
 270         mutex_destroy(&srv_sess->lock);
 271         kfree(srv_sess);
 272 }
 273
 274 static int create_sess(struct rtrs_srv *rtrs)
 275 {
 276         struct rnbd_srv_session *srv_sess;
 277         char sessname[NAME_MAX];
 278         int err;
 279
 280         err = rtrs_srv_get_sess_name(rtrs, sessname, sizeof(sessname));
 281         if (err) {
 282                 pr_err("rtrs_srv_get_sess_name(%s): %d\n", sessname, err);
 283
 284                 return err;
 285         }
 286         srv_sess = kzalloc(sizeof(*srv_sess), GFP_KERNEL);
 287         if (!srv_sess)
 288                 return -ENOMEM;
 289
 290         srv_sess->queue_depth = rtrs_srv_get_queue_depth(rtrs);
 291         err = bioset_init(&srv_sess->sess_bio_set, srv_sess->queue_depth,
 292                           offsetof(struct rnbd_dev_blk_io, bio),
 293                           BIOSET_NEED_BVECS);
 294         if (err) {
 295                 pr_err("Allocating srv_session for session %s failed\n",
 296                        sessname);
 297                 kfree(srv_sess);
 298                 return err;
 299         }
 300
 301         xa_init_flags(&srv_sess->index_idr, XA_FLAGS_ALLOC);
 302         INIT_LIST_HEAD(&srv_sess->sess_dev_list);
 303         mutex_init(&srv_sess->lock);
 304         mutex_lock(&sess_lock);
 305         list_add(&srv_sess->list, &sess_list);
 306         mutex_unlock(&sess_lock);
 307
 308         srv_sess->rtrs = rtrs;
 309         strlcpy(srv_sess->sessname, sessname, sizeof(srv_sess->sessname));
 310
 311         rtrs_srv_set_sess_priv(rtrs, srv_sess);
 312
 313         return 0;
 314 }
 315
 316 static int rnbd_srv_link_ev(struct rtrs_srv *rtrs,
 317                              enum rtrs_srv_link_ev ev, void *priv)
 318 {
 319         struct rnbd_srv_session *srv_sess = priv;
 320
 321         switch (ev) {
 322         case RTRS_SRV_LINK_EV_CONNECTED:
 323                 return create_sess(rtrs);
 324
 325         case RTRS_SRV_LINK_EV_DISCONNECTED:
 326                 if (WARN_ON_ONCE(!srv_sess))
 327                         return -EINVAL;
 328
 329                 destroy_sess(srv_sess);
 330                 return 0;
 331
 332         default:
 333                 pr_warn("Received unknown RTRS session event %d from session %s\n",
 334                         ev, srv_sess->sessname);
 335                 return -EINVAL;
 336         }
 337 }
 338
 339 void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev)
 340 {
 341         mutex_lock(&sess_dev->sess->lock);
 342         rnbd_srv_destroy_dev_session_sysfs(sess_dev);
 343         mutex_unlock(&sess_dev->sess->lock);
 344         sess_dev->keep_id = true;
 345 }
 346
 347 static int process_msg_close(struct rtrs_srv *rtrs,
 348                              struct rnbd_srv_session *srv_sess,
 349                              void *data, size_t datalen, const void *usr,
 350                              size_t usrlen)
 351 {
 352         const struct rnbd_msg_close *close_msg = usr;
 353         struct rnbd_srv_sess_dev *sess_dev;
 354
 355         sess_dev = rnbd_get_sess_dev(le32_to_cpu(close_msg->device_id),
 356                                       srv_sess);
 357         if (IS_ERR(sess_dev))
 358                 return 0;
 359
 360         rnbd_put_sess_dev(sess_dev);
 361         mutex_lock(&srv_sess->lock);
 362         rnbd_srv_destroy_dev_session_sysfs(sess_dev);
 363         mutex_unlock(&srv_sess->lock);
 364         return 0;
 365 }
 366
 367 static int process_msg_open(struct rtrs_srv *rtrs,
 368                             struct rnbd_srv_session *srv_sess,
 369                             const void *msg, size_t len,
 370                             void *data, size_t datalen);
 371
 372 static int process_msg_sess_info(struct rtrs_srv *rtrs,
 373                                  struct rnbd_srv_session *srv_sess,
 374                                  const void *msg, size_t len,
 375                                  void *data, size_t datalen);
 376
 377 static int rnbd_srv_rdma_ev(struct rtrs_srv *rtrs, void *priv,
 378                              struct rtrs_srv_op *id, int dir,
 379                              void *data, size_t datalen, const void *usr,
 380                              size_t usrlen)
 381 {
 382         struct rnbd_srv_session *srv_sess = priv;
 383         const struct rnbd_msg_hdr *hdr = usr;
 384         int ret = 0;
 385         u16 type;
 386
 387         if (WARN_ON_ONCE(!srv_sess))
 388                 return -ENODEV;
 389
 390         type = le16_to_cpu(hdr->type);
 391
 392         switch (type) {
 393         case RNBD_MSG_IO:
 394                 return process_rdma(rtrs, srv_sess, id, data, datalen, usr,
 395                                     usrlen);
 396         case RNBD_MSG_CLOSE:
 397                 ret = process_msg_close(rtrs, srv_sess, data, datalen,
 398                                         usr, usrlen);
 399                 break;
 400         case RNBD_MSG_OPEN:
 401                 ret = process_msg_open(rtrs, srv_sess, usr, usrlen,
 402                                        data, datalen);
 403                 break;
 404         case RNBD_MSG_SESS_INFO:
 405                 ret = process_msg_sess_info(rtrs, srv_sess, usr, usrlen,
 406                                             data, datalen);
 407                 break;
 408         default:
 409                 pr_warn("Received unexpected message type %d with dir %d from session %s\n",
 410                         type, dir, srv_sess->sessname);
 411                 return -EINVAL;
 412         }
 413
 414         rtrs_srv_resp_rdma(id, ret);
 415         return 0;
 416 }
 417
 418 static struct rnbd_srv_sess_dev
 419 *rnbd_sess_dev_alloc(struct rnbd_srv_session *srv_sess)
 420 {
 421         struct rnbd_srv_sess_dev *sess_dev;
 422         int error;
 423
 424         sess_dev = kzalloc(sizeof(*sess_dev), GFP_KERNEL);
 425         if (!sess_dev)
 426                 return ERR_PTR(-ENOMEM);
 427
 428         error = xa_alloc(&srv_sess->index_idr, &sess_dev->device_id, sess_dev,
 429                          xa_limit_32b, GFP_NOWAIT);
 430         if (error < 0) {
 431                 pr_warn("Allocating idr failed, err: %d\n", error);
 432                 kfree(sess_dev);
 433                 return ERR_PTR(error);
 434         }
 435
 436         return sess_dev;
 437 }
 438
 439 static struct rnbd_srv_dev *rnbd_srv_init_srv_dev(const char *id)
 440 {
 441         struct rnbd_srv_dev *dev;
 442
 443         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 444         if (!dev)
 445                 return ERR_PTR(-ENOMEM);
 446
 447         strlcpy(dev->id, id, sizeof(dev->id));
 448         kref_init(&dev->kref);
 449         INIT_LIST_HEAD(&dev->sess_dev_list);
 450         mutex_init(&dev->lock);
 451
 452         return dev;
 453 }
 454
 455 static struct rnbd_srv_dev *
 456 rnbd_srv_find_or_add_srv_dev(struct rnbd_srv_dev *new_dev)
 457 {
 458         struct rnbd_srv_dev *dev;
 459
 460         spin_lock(&dev_lock);
 461         list_for_each_entry(dev, &dev_list, list) {
 462                 if (!strncmp(dev->id, new_dev->id, sizeof(dev->id))) {
 463                         if (!kref_get_unless_zero(&dev->kref))
 464                                 /*
 465                                  * We lost the race, device is almost dead.
 466                                  *  Continue traversing to find a valid one.
 467                                  */
 468                                 continue;
 469                         spin_unlock(&dev_lock);
 470                         return dev;
 471                 }
 472         }
 473         list_add(&new_dev->list, &dev_list);
 474         spin_unlock(&dev_lock);
 475
 476         return new_dev;
 477 }
 478
 479 static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev,
 480                                             struct rnbd_srv_session *srv_sess,
 481                                             enum rnbd_access_mode access_mode)
 482 {
 483         int ret = -EPERM;
 484
 485         mutex_lock(&srv_dev->lock);
 486
 487         switch (access_mode) {
 488         case RNBD_ACCESS_RO:
 489                 ret = 0;
 490                 break;
 491         case RNBD_ACCESS_RW:
 492                 if (srv_dev->open_write_cnt == 0)  {
 493                         srv_dev->open_write_cnt++;
 494                         ret = 0;
 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->id, srv_sess->sessname,
 498                                srv_dev->open_write_cnt,
 499                                rnbd_access_mode_str(access_mode));
 500                 }
 501                 break;
 502         case RNBD_ACCESS_MIGRATION:
 503                 if (srv_dev->open_write_cnt < 2) {
 504                         srv_dev->open_write_cnt++;
 505                         ret = 0;
 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->id, srv_sess->sessname,
 509                                srv_dev->open_write_cnt,
 510                                rnbd_access_mode_str(access_mode));
 511                 }
 512                 break;
 513         default:
 514                 pr_err("Received mapping request for device '%s' on session %s with invalid access mode: %d\n",
 515                        srv_dev->id, srv_sess->sessname, access_mode);
 516                 ret = -EINVAL;
 517         }
 518
 519         mutex_unlock(&srv_dev->lock);
 520
 521         return ret;
 522 }
 523
 524 static struct rnbd_srv_dev *
 525 rnbd_srv_get_or_create_srv_dev(struct rnbd_dev *rnbd_dev,
 526                                 struct rnbd_srv_session *srv_sess,
 527                                 enum rnbd_access_mode access_mode)
 528 {
 529         int ret;
 530         struct rnbd_srv_dev *new_dev, *dev;
 531
 532         new_dev = rnbd_srv_init_srv_dev(rnbd_dev->name);
 533         if (IS_ERR(new_dev))
 534                 return new_dev;
 535
 536         dev = rnbd_srv_find_or_add_srv_dev(new_dev);
 537         if (dev != new_dev)
 538                 kfree(new_dev);
 539
 540         ret = rnbd_srv_check_update_open_perm(dev, srv_sess, access_mode);
 541         if (ret) {
 542                 rnbd_put_srv_dev(dev);
 543                 return ERR_PTR(ret);
 544         }
 545
 546         return dev;
 547 }
 548
 549 static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
 550                                         struct rnbd_srv_sess_dev *sess_dev)
 551 {
 552         struct rnbd_dev *rnbd_dev = sess_dev->rnbd_dev;
 553         struct request_queue *q = bdev_get_queue(rnbd_dev->bdev);
 554
 555         rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP);
 556         rsp->device_id =
 557                 cpu_to_le32(sess_dev->device_id);
 558         rsp->nsectors =
 559                 cpu_to_le64(get_capacity(rnbd_dev->bdev->bd_disk));
 560         rsp->logical_block_size =
 561                 cpu_to_le16(bdev_logical_block_size(rnbd_dev->bdev));
 562         rsp->physical_block_size =
 563                 cpu_to_le16(bdev_physical_block_size(rnbd_dev->bdev));
 564         rsp->max_segments =
 565                 cpu_to_le16(rnbd_dev_get_max_segs(rnbd_dev));
 566         rsp->max_hw_sectors =
 567                 cpu_to_le32(rnbd_dev_get_max_hw_sects(rnbd_dev));
 568         rsp->max_write_same_sectors =
 569                 cpu_to_le32(bdev_write_same(rnbd_dev->bdev));
 570         rsp->max_discard_sectors =
 571                 cpu_to_le32(rnbd_dev_get_max_discard_sects(rnbd_dev));
 572         rsp->discard_granularity =
 573                 cpu_to_le32(rnbd_dev_get_discard_granularity(rnbd_dev));
 574         rsp->discard_alignment =
 575                 cpu_to_le32(rnbd_dev_get_discard_alignment(rnbd_dev));
 576         rsp->secure_discard =
 577                 cpu_to_le16(rnbd_dev_get_secure_discard(rnbd_dev));
 578         rsp->rotational = !blk_queue_nonrot(q);
 579         rsp->cache_policy = 0;
 580         if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 581                 rsp->cache_policy |= RNBD_WRITEBACK;
 582         if (blk_queue_fua(q))
 583                 rsp->cache_policy |= RNBD_FUA;
 584 }
 585
 586 static struct rnbd_srv_sess_dev *
 587 rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess,
 588                               const struct rnbd_msg_open *open_msg,
 589                               struct rnbd_dev *rnbd_dev, fmode_t open_flags,
 590                               struct rnbd_srv_dev *srv_dev)
 591 {
 592         struct rnbd_srv_sess_dev *sdev = rnbd_sess_dev_alloc(srv_sess);
 593
 594         if (IS_ERR(sdev))
 595                 return sdev;
 596
 597         kref_init(&sdev->kref);
 598
 599         strlcpy(sdev->pathname, open_msg->dev_name, sizeof(sdev->pathname));
 600
 601         sdev->rnbd_dev          = rnbd_dev;
 602         sdev->sess              = srv_sess;
 603         sdev->dev               = srv_dev;
 604         sdev->open_flags        = open_flags;
 605         sdev->access_mode       = open_msg->access_mode;
 606
 607         return sdev;
 608 }
 609
 610 static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess,
 611                                      const char *dev_name)
 612 {
 613         char *full_path;
 614         char *a, *b;
 615
 616         full_path = kmalloc(PATH_MAX, GFP_KERNEL);
 617         if (!full_path)
 618                 return ERR_PTR(-ENOMEM);
 619
 620         /*
 621          * Replace %SESSNAME% with a real session name in order to
 622          * create device namespace.
 623          */
 624         a = strnstr(dev_search_path, "%SESSNAME%", sizeof(dev_search_path));
 625         if (a) {
 626                 int len = a - dev_search_path;
 627
 628                 len = snprintf(full_path, PATH_MAX, "%.*s/%s/%s", len,
 629                                dev_search_path, srv_sess->sessname, dev_name);
 630                 if (len >= PATH_MAX) {
 631                         pr_err("Too long path: %s, %s, %s\n",
 632                                dev_search_path, srv_sess->sessname, dev_name);
 633                         kfree(full_path);
 634                         return ERR_PTR(-EINVAL);
 635                 }
 636         } else {
 637                 snprintf(full_path, PATH_MAX, "%s/%s",
 638                          dev_search_path, dev_name);
 639         }
 640
 641         /* eliminitate duplicated slashes */
 642         a = strchr(full_path, '/');
 643         b = a;
 644         while (*b != '\0') {
 645                 if (*b == '/' && *a == '/') {
 646                         b++;
 647                 } else {
 648                         a++;
 649                         *a = *b;
 650                         b++;
 651                 }
 652         }
 653         a++;
 654         *a = '\0';
 655
 656         return full_path;
 657 }
 658
 659 static int process_msg_sess_info(struct rtrs_srv *rtrs,
 660                                  struct rnbd_srv_session *srv_sess,
 661                                  const void *msg, size_t len,
 662                                  void *data, size_t datalen)
 663 {
 664         const struct rnbd_msg_sess_info *sess_info_msg = msg;
 665         struct rnbd_msg_sess_info_rsp *rsp = data;
 666
 667         srv_sess->ver = min_t(u8, sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
 668         pr_debug("Session %s using protocol version %d (client version: %d, server version: %d)\n",
 669                  srv_sess->sessname, srv_sess->ver,
 670                  sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
 671
 672         rsp->hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO_RSP);
 673         rsp->ver = srv_sess->ver;
 674
 675         return 0;
 676 }
 677
 678 /**
 679  * find_srv_sess_dev() - a dev is already opened by this name
 680  * @srv_sess:   the session to search.
 681  * @dev_name:   string containing the name of the device.
 682  *
 683  * Return struct rnbd_srv_sess_dev if srv_sess already opened the dev_name
 684  * NULL if the session didn't open the device yet.
 685  */
 686 static struct rnbd_srv_sess_dev *
 687 find_srv_sess_dev(struct rnbd_srv_session *srv_sess, const char *dev_name)
 688 {
 689         struct rnbd_srv_sess_dev *sess_dev;
 690
 691         if (list_empty(&srv_sess->sess_dev_list))
 692                 return NULL;
 693
 694         list_for_each_entry(sess_dev, &srv_sess->sess_dev_list, sess_list)
 695                 if (!strcmp(sess_dev->pathname, dev_name))
 696                         return sess_dev;
 697
 698         return NULL;
 699 }
 700
 701 static int process_msg_open(struct rtrs_srv *rtrs,
 702                             struct rnbd_srv_session *srv_sess,
 703                             const void *msg, size_t len,
 704                             void *data, size_t datalen)
 705 {
 706         int ret;
 707         struct rnbd_srv_dev *srv_dev;
 708         struct rnbd_srv_sess_dev *srv_sess_dev;
 709         const struct rnbd_msg_open *open_msg = msg;
 710         fmode_t open_flags;
 711         char *full_path;
 712         struct rnbd_dev *rnbd_dev;
 713         struct rnbd_msg_open_rsp *rsp = data;
 714
 715         pr_debug("Open message received: session='%s' path='%s' access_mode=%d\n",
 716                  srv_sess->sessname, open_msg->dev_name,
 717                  open_msg->access_mode);
 718         open_flags = FMODE_READ;
 719         if (open_msg->access_mode != RNBD_ACCESS_RO)
 720                 open_flags |= FMODE_WRITE;
 721
 722         mutex_lock(&srv_sess->lock);
 723
 724         srv_sess_dev = find_srv_sess_dev(srv_sess, open_msg->dev_name);
 725         if (srv_sess_dev)
 726                 goto fill_response;
 727
 728         if ((strlen(dev_search_path) + strlen(open_msg->dev_name))
 729             >= PATH_MAX) {
 730                 pr_err("Opening device for session %s failed, device path too long. '%s/%s' is longer than PATH_MAX (%d)\n",
 731                        srv_sess->sessname, dev_search_path, open_msg->dev_name,
 732                        PATH_MAX);
 733                 ret = -EINVAL;
 734                 goto reject;
 735         }
 736         if (strstr(open_msg->dev_name, "..")) {
 737                 pr_err("Opening device for session %s failed, device path %s contains relative path ..\n",
 738                        srv_sess->sessname, open_msg->dev_name);
 739                 ret = -EINVAL;
 740                 goto reject;
 741         }
 742         full_path = rnbd_srv_get_full_path(srv_sess, open_msg->dev_name);
 743         if (IS_ERR(full_path)) {
 744                 ret = PTR_ERR(full_path);
 745                 pr_err("Opening device '%s' for client %s failed, failed to get device full path, err: %d\n",
 746                        open_msg->dev_name, srv_sess->sessname, ret);
 747                 goto reject;
 748         }
 749
 750         rnbd_dev = rnbd_dev_open(full_path, open_flags,
 751                                  &srv_sess->sess_bio_set);
 752         if (IS_ERR(rnbd_dev)) {
 753                 pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %ld\n",
 754                        full_path, srv_sess->sessname, PTR_ERR(rnbd_dev));
 755                 ret = PTR_ERR(rnbd_dev);
 756                 goto free_path;
 757         }
 758
 759         srv_dev = rnbd_srv_get_or_create_srv_dev(rnbd_dev, srv_sess,
 760                                                   open_msg->access_mode);
 761         if (IS_ERR(srv_dev)) {
 762                 pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %ld\n",
 763                        full_path, srv_sess->sessname, PTR_ERR(srv_dev));
 764                 ret = PTR_ERR(srv_dev);
 765                 goto rnbd_dev_close;
 766         }
 767
 768         srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
 769                                                      rnbd_dev, open_flags,
 770                                                      srv_dev);
 771         if (IS_ERR(srv_sess_dev)) {
 772                 pr_err("Opening device '%s' on session %s failed, creating sess_dev failed, err: %ld\n",
 773                        full_path, srv_sess->sessname, PTR_ERR(srv_sess_dev));
 774                 ret = PTR_ERR(srv_sess_dev);
 775                 goto srv_dev_put;
 776         }
 777
 778         /* Create the srv_dev sysfs files if they haven't been created yet. The
 779          * reason to delay the creation is not to create the sysfs files before
 780          * we are sure the device can be opened.
 781          */
 782         mutex_lock(&srv_dev->lock);
 783         if (!srv_dev->dev_kobj.state_in_sysfs) {
 784                 ret = rnbd_srv_create_dev_sysfs(srv_dev, rnbd_dev->bdev,
 785                                                  rnbd_dev->name);
 786                 if (ret) {
 787                         mutex_unlock(&srv_dev->lock);
 788                         rnbd_srv_err(srv_sess_dev,
 789                                       "Opening device failed, failed to create device sysfs files, err: %d\n",
 790                                       ret);
 791                         goto free_srv_sess_dev;
 792                 }
 793         }
 794
 795         ret = rnbd_srv_create_dev_session_sysfs(srv_sess_dev);
 796         if (ret) {
 797                 mutex_unlock(&srv_dev->lock);
 798                 rnbd_srv_err(srv_sess_dev,
 799                               "Opening device failed, failed to create dev client sysfs files, err: %d\n",
 800                               ret);
 801                 goto free_srv_sess_dev;
 802         }
 803
 804         list_add(&srv_sess_dev->dev_list, &srv_dev->sess_dev_list);
 805         mutex_unlock(&srv_dev->lock);
 806
 807         list_add(&srv_sess_dev->sess_list, &srv_sess->sess_dev_list);
 808
 809         rnbd_srv_info(srv_sess_dev, "Opened device '%s'\n", srv_dev->id);
 810
 811         kfree(full_path);
 812
 813 fill_response:
 814         rnbd_srv_fill_msg_open_rsp(rsp, srv_sess_dev);
 815         mutex_unlock(&srv_sess->lock);
 816         return 0;
 817
 818 free_srv_sess_dev:
 819         xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id);
 820         synchronize_rcu();
 821         kfree(srv_sess_dev);
 822 srv_dev_put:
 823         if (open_msg->access_mode != RNBD_ACCESS_RO) {
 824                 mutex_lock(&srv_dev->lock);
 825                 srv_dev->open_write_cnt--;
 826                 mutex_unlock(&srv_dev->lock);
 827         }
 828         rnbd_put_srv_dev(srv_dev);
 829 rnbd_dev_close:
 830         rnbd_dev_close(rnbd_dev);
 831 free_path:
 832         kfree(full_path);
 833 reject:
 834         mutex_unlock(&srv_sess->lock);
 835         return ret;
 836 }
 837
 838 static struct rtrs_srv_ctx *rtrs_ctx;
 839
 840 static struct rtrs_srv_ops rtrs_ops;
 841 static int __init rnbd_srv_init_module(void)
 842 {
 843         int err;
 844
 845         BUILD_BUG_ON(sizeof(struct rnbd_msg_hdr) != 4);
 846         BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info) != 36);
 847         BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info_rsp) != 36);
 848         BUILD_BUG_ON(sizeof(struct rnbd_msg_open) != 264);
 849         BUILD_BUG_ON(sizeof(struct rnbd_msg_close) != 8);
 850         BUILD_BUG_ON(sizeof(struct rnbd_msg_open_rsp) != 56);
 851         rtrs_ops = (struct rtrs_srv_ops) {
 852                 .rdma_ev = rnbd_srv_rdma_ev,
 853                 .link_ev = rnbd_srv_link_ev,
 854         };
 855         rtrs_ctx = rtrs_srv_open(&rtrs_ops, port_nr);
 856         if (IS_ERR(rtrs_ctx)) {
 857                 err = PTR_ERR(rtrs_ctx);
 858                 pr_err("rtrs_srv_open(), err: %d\n", err);
 859                 return err;
 860         }
 861
 862         err = rnbd_srv_create_sysfs_files();
 863         if (err) {
 864                 pr_err("rnbd_srv_create_sysfs_files(), err: %d\n", err);
 865                 rtrs_srv_close(rtrs_ctx);
 866                 return err;
 867         }
 868
 869         return 0;
 870 }
 871
 872 static void __exit rnbd_srv_cleanup_module(void)
 873 {
 874         rtrs_srv_close(rtrs_ctx);
 875         WARN_ON(!list_empty(&sess_list));
 876         rnbd_srv_destroy_sysfs_files();
 877 }
 878
 879 module_init(rnbd_srv_init_module);
 880 module_exit(rnbd_srv_cleanup_module);