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
 128         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
 129         if (!priv)
 130                 return -ENOMEM;
 131
 132         dev_id = le32_to_cpu(msg->device_id);
 133
 134         sess_dev = rnbd_get_sess_dev(dev_id, srv_sess);
 135         if (IS_ERR(sess_dev)) {
 136                 pr_err_ratelimited("Got I/O request on session %s for unknown device id %d\n",
 137                                    srv_sess->sessname, dev_id);
 138                 err = -ENOTCONN;
 139                 goto err;
 140         }
 141
 142         priv->sess_dev = sess_dev;
 143         priv->id = id;
 144
 145         err = rnbd_dev_submit_io(sess_dev->rnbd_dev, le64_to_cpu(msg->sector),
 146                                   data, datalen, le32_to_cpu(msg->bi_size),
 147                                   le32_to_cpu(msg->rw),
 148                                   srv_sess->ver < RNBD_PROTO_VER_MAJOR ||
 149                                   usrlen < sizeof(*msg) ?
 150                                   0 : le16_to_cpu(msg->prio), priv);
 151         if (unlikely(err)) {
 152                 rnbd_srv_err(sess_dev, "Submitting I/O to device failed, err: %d\n",
 153                               err);
 154                 goto sess_dev_put;
 155         }
 156
 157         return 0;
 158
 159 sess_dev_put:
 160         rnbd_put_sess_dev(sess_dev);
 161 err:
 162         kfree(priv);
 163         return err;
 164 }
 165
 166 static void destroy_device(struct rnbd_srv_dev *dev)
 167 {
 168         WARN_ONCE(!list_empty(&dev->sess_dev_list),
 169                   "Device %s is being destroyed but still in use!\n",
 170                   dev->id);
 171
 172         spin_lock(&dev_lock);
 173         list_del(&dev->list);
 174         spin_unlock(&dev_lock);
 175
 176         mutex_destroy(&dev->lock);
 177         if (dev->dev_kobj.state_in_sysfs)
 178                 /*
 179                  * Destroy kobj only if it was really created.
 180                  */
 181                 rnbd_srv_destroy_dev_sysfs(dev);
 182         else
 183                 kfree(dev);
 184 }
 185
 186 static void destroy_device_cb(struct kref *kref)
 187 {
 188         struct rnbd_srv_dev *dev;
 189
 190         dev = container_of(kref, struct rnbd_srv_dev, kref);
 191
 192         destroy_device(dev);
 193 }
 194
 195 static void rnbd_put_srv_dev(struct rnbd_srv_dev *dev)
 196 {
 197         kref_put(&dev->kref, destroy_device_cb);
 198 }
 199
 200 void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev)
 201 {
 202         DECLARE_COMPLETION_ONSTACK(dc);
 203
 204         xa_erase(&sess_dev->sess->index_idr, sess_dev->device_id);
 205         synchronize_rcu();
 206         sess_dev->destroy_comp = &dc;
 207         rnbd_put_sess_dev(sess_dev);
 208         wait_for_completion(&dc); /* wait for inflights to drop to zero */
 209
 210         rnbd_dev_close(sess_dev->rnbd_dev);
 211         list_del(&sess_dev->sess_list);
 212         mutex_lock(&sess_dev->dev->lock);
 213         list_del(&sess_dev->dev_list);
 214         if (sess_dev->open_flags & FMODE_WRITE)
 215                 sess_dev->dev->open_write_cnt--;
 216         mutex_unlock(&sess_dev->dev->lock);
 217
 218         rnbd_put_srv_dev(sess_dev->dev);
 219
 220         rnbd_srv_info(sess_dev, "Device closed\n");
 221         kfree(sess_dev);
 222 }
 223
 224 static void destroy_sess(struct rnbd_srv_session *srv_sess)
 225 {
 226         struct rnbd_srv_sess_dev *sess_dev, *tmp;
 227
 228         if (list_empty(&srv_sess->sess_dev_list))
 229                 goto out;
 230
 231         mutex_lock(&srv_sess->lock);
 232         list_for_each_entry_safe(sess_dev, tmp, &srv_sess->sess_dev_list,
 233                                  sess_list)
 234                 rnbd_srv_destroy_dev_session_sysfs(sess_dev);
 235         mutex_unlock(&srv_sess->lock);
 236
 237 out:
 238         xa_destroy(&srv_sess->index_idr);
 239         bioset_exit(&srv_sess->sess_bio_set);
 240
 241         pr_info("RTRS Session %s disconnected\n", srv_sess->sessname);
 242
 243         mutex_lock(&sess_lock);
 244         list_del(&srv_sess->list);
 245         mutex_unlock(&sess_lock);
 246
 247         mutex_destroy(&srv_sess->lock);
 248         kfree(srv_sess);
 249 }
 250
 251 static int create_sess(struct rtrs_srv *rtrs)
 252 {
 253         struct rnbd_srv_session *srv_sess;
 254         char sessname[NAME_MAX];
 255         int err;
 256
 257         err = rtrs_srv_get_sess_name(rtrs, sessname, sizeof(sessname));
 258         if (err) {
 259                 pr_err("rtrs_srv_get_sess_name(%s): %d\n", sessname, err);
 260
 261                 return err;
 262         }
 263         srv_sess = kzalloc(sizeof(*srv_sess), GFP_KERNEL);
 264         if (!srv_sess)
 265                 return -ENOMEM;
 266
 267         srv_sess->queue_depth = rtrs_srv_get_queue_depth(rtrs);
 268         err = bioset_init(&srv_sess->sess_bio_set, srv_sess->queue_depth,
 269                           offsetof(struct rnbd_dev_blk_io, bio),
 270                           BIOSET_NEED_BVECS);
 271         if (err) {
 272                 pr_err("Allocating srv_session for session %s failed\n",
 273                        sessname);
 274                 kfree(srv_sess);
 275                 return err;
 276         }
 277
 278         xa_init_flags(&srv_sess->index_idr, XA_FLAGS_ALLOC);
 279         INIT_LIST_HEAD(&srv_sess->sess_dev_list);
 280         mutex_init(&srv_sess->lock);
 281         mutex_lock(&sess_lock);
 282         list_add(&srv_sess->list, &sess_list);
 283         mutex_unlock(&sess_lock);
 284
 285         srv_sess->rtrs = rtrs;
 286         strlcpy(srv_sess->sessname, sessname, sizeof(srv_sess->sessname));
 287
 288         rtrs_srv_set_sess_priv(rtrs, srv_sess);
 289
 290         return 0;
 291 }
 292
 293 static int rnbd_srv_link_ev(struct rtrs_srv *rtrs,
 294                              enum rtrs_srv_link_ev ev, void *priv)
 295 {
 296         struct rnbd_srv_session *srv_sess = priv;
 297
 298         switch (ev) {
 299         case RTRS_SRV_LINK_EV_CONNECTED:
 300                 return create_sess(rtrs);
 301
 302         case RTRS_SRV_LINK_EV_DISCONNECTED:
 303                 if (WARN_ON_ONCE(!srv_sess))
 304                         return -EINVAL;
 305
 306                 destroy_sess(srv_sess);
 307                 return 0;
 308
 309         default:
 310                 pr_warn("Received unknown RTRS session event %d from session %s\n",
 311                         ev, srv_sess->sessname);
 312                 return -EINVAL;
 313         }
 314 }
 315
 316 static int process_msg_close(struct rtrs_srv *rtrs,
 317                              struct rnbd_srv_session *srv_sess,
 318                              void *data, size_t datalen, const void *usr,
 319                              size_t usrlen)
 320 {
 321         const struct rnbd_msg_close *close_msg = usr;
 322         struct rnbd_srv_sess_dev *sess_dev;
 323
 324         sess_dev = rnbd_get_sess_dev(le32_to_cpu(close_msg->device_id),
 325                                       srv_sess);
 326         if (IS_ERR(sess_dev))
 327                 return 0;
 328
 329         rnbd_put_sess_dev(sess_dev);
 330         mutex_lock(&srv_sess->lock);
 331         rnbd_srv_destroy_dev_session_sysfs(sess_dev);
 332         mutex_unlock(&srv_sess->lock);
 333         return 0;
 334 }
 335
 336 static int process_msg_open(struct rtrs_srv *rtrs,
 337                             struct rnbd_srv_session *srv_sess,
 338                             const void *msg, size_t len,
 339                             void *data, size_t datalen);
 340
 341 static int process_msg_sess_info(struct rtrs_srv *rtrs,
 342                                  struct rnbd_srv_session *srv_sess,
 343                                  const void *msg, size_t len,
 344                                  void *data, size_t datalen);
 345
 346 static int rnbd_srv_rdma_ev(struct rtrs_srv *rtrs, void *priv,
 347                              struct rtrs_srv_op *id, int dir,
 348                              void *data, size_t datalen, const void *usr,
 349                              size_t usrlen)
 350 {
 351         struct rnbd_srv_session *srv_sess = priv;
 352         const struct rnbd_msg_hdr *hdr = usr;
 353         int ret = 0;
 354         u16 type;
 355
 356         if (WARN_ON_ONCE(!srv_sess))
 357                 return -ENODEV;
 358
 359         type = le16_to_cpu(hdr->type);
 360
 361         switch (type) {
 362         case RNBD_MSG_IO:
 363                 return process_rdma(rtrs, srv_sess, id, data, datalen, usr,
 364                                     usrlen);
 365         case RNBD_MSG_CLOSE:
 366                 ret = process_msg_close(rtrs, srv_sess, data, datalen,
 367                                         usr, usrlen);
 368                 break;
 369         case RNBD_MSG_OPEN:
 370                 ret = process_msg_open(rtrs, srv_sess, usr, usrlen,
 371                                        data, datalen);
 372                 break;
 373         case RNBD_MSG_SESS_INFO:
 374                 ret = process_msg_sess_info(rtrs, srv_sess, usr, usrlen,
 375                                             data, datalen);
 376                 break;
 377         default:
 378                 pr_warn("Received unexpected message type %d with dir %d from session %s\n",
 379                         type, dir, srv_sess->sessname);
 380                 return -EINVAL;
 381         }
 382
 383         rtrs_srv_resp_rdma(id, ret);
 384         return 0;
 385 }
 386
 387 static struct rnbd_srv_sess_dev
 388 *rnbd_sess_dev_alloc(struct rnbd_srv_session *srv_sess)
 389 {
 390         struct rnbd_srv_sess_dev *sess_dev;
 391         int error;
 392
 393         sess_dev = kzalloc(sizeof(*sess_dev), GFP_KERNEL);
 394         if (!sess_dev)
 395                 return ERR_PTR(-ENOMEM);
 396
 397         error = xa_alloc(&srv_sess->index_idr, &sess_dev->device_id, sess_dev,
 398                          xa_limit_32b, GFP_NOWAIT);
 399         if (error < 0) {
 400                 pr_warn("Allocating idr failed, err: %d\n", error);
 401                 kfree(sess_dev);
 402                 return ERR_PTR(error);
 403         }
 404
 405         return sess_dev;
 406 }
 407
 408 static struct rnbd_srv_dev *rnbd_srv_init_srv_dev(const char *id)
 409 {
 410         struct rnbd_srv_dev *dev;
 411
 412         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 413         if (!dev)
 414                 return ERR_PTR(-ENOMEM);
 415
 416         strlcpy(dev->id, id, sizeof(dev->id));
 417         kref_init(&dev->kref);
 418         INIT_LIST_HEAD(&dev->sess_dev_list);
 419         mutex_init(&dev->lock);
 420
 421         return dev;
 422 }
 423
 424 static struct rnbd_srv_dev *
 425 rnbd_srv_find_or_add_srv_dev(struct rnbd_srv_dev *new_dev)
 426 {
 427         struct rnbd_srv_dev *dev;
 428
 429         spin_lock(&dev_lock);
 430         list_for_each_entry(dev, &dev_list, list) {
 431                 if (!strncmp(dev->id, new_dev->id, sizeof(dev->id))) {
 432                         if (!kref_get_unless_zero(&dev->kref))
 433                                 /*
 434                                  * We lost the race, device is almost dead.
 435                                  *  Continue traversing to find a valid one.
 436                                  */
 437                                 continue;
 438                         spin_unlock(&dev_lock);
 439                         return dev;
 440                 }
 441         }
 442         list_add(&new_dev->list, &dev_list);
 443         spin_unlock(&dev_lock);
 444
 445         return new_dev;
 446 }
 447
 448 static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev,
 449                                             struct rnbd_srv_session *srv_sess,
 450                                             enum rnbd_access_mode access_mode)
 451 {
 452         int ret = -EPERM;
 453
 454         mutex_lock(&srv_dev->lock);
 455
 456         switch (access_mode) {
 457         case RNBD_ACCESS_RO:
 458                 ret = 0;
 459                 break;
 460         case RNBD_ACCESS_RW:
 461                 if (srv_dev->open_write_cnt == 0)  {
 462                         srv_dev->open_write_cnt++;
 463                         ret = 0;
 464                 } else {
 465                         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",
 466                                srv_dev->id, srv_sess->sessname,
 467                                srv_dev->open_write_cnt,
 468                                rnbd_access_mode_str(access_mode));
 469                 }
 470                 break;
 471         case RNBD_ACCESS_MIGRATION:
 472                 if (srv_dev->open_write_cnt < 2) {
 473                         srv_dev->open_write_cnt++;
 474                         ret = 0;
 475                 } else {
 476                         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",
 477                                srv_dev->id, srv_sess->sessname,
 478                                srv_dev->open_write_cnt,
 479                                rnbd_access_mode_str(access_mode));
 480                 }
 481                 break;
 482         default:
 483                 pr_err("Received mapping request for device '%s' on session %s with invalid access mode: %d\n",
 484                        srv_dev->id, srv_sess->sessname, access_mode);
 485                 ret = -EINVAL;
 486         }
 487
 488         mutex_unlock(&srv_dev->lock);
 489
 490         return ret;
 491 }
 492
 493 static struct rnbd_srv_dev *
 494 rnbd_srv_get_or_create_srv_dev(struct rnbd_dev *rnbd_dev,
 495                                 struct rnbd_srv_session *srv_sess,
 496                                 enum rnbd_access_mode access_mode)
 497 {
 498         int ret;
 499         struct rnbd_srv_dev *new_dev, *dev;
 500
 501         new_dev = rnbd_srv_init_srv_dev(rnbd_dev->name);
 502         if (IS_ERR(new_dev))
 503                 return new_dev;
 504
 505         dev = rnbd_srv_find_or_add_srv_dev(new_dev);
 506         if (dev != new_dev)
 507                 kfree(new_dev);
 508
 509         ret = rnbd_srv_check_update_open_perm(dev, srv_sess, access_mode);
 510         if (ret) {
 511                 rnbd_put_srv_dev(dev);
 512                 return ERR_PTR(ret);
 513         }
 514
 515         return dev;
 516 }
 517
 518 static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
 519                                         struct rnbd_srv_sess_dev *sess_dev)
 520 {
 521         struct rnbd_dev *rnbd_dev = sess_dev->rnbd_dev;
 522
 523         rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP);
 524         rsp->device_id =
 525                 cpu_to_le32(sess_dev->device_id);
 526         rsp->nsectors =
 527                 cpu_to_le64(get_capacity(rnbd_dev->bdev->bd_disk));
 528         rsp->logical_block_size =
 529                 cpu_to_le16(bdev_logical_block_size(rnbd_dev->bdev));
 530         rsp->physical_block_size =
 531                 cpu_to_le16(bdev_physical_block_size(rnbd_dev->bdev));
 532         rsp->max_segments =
 533                 cpu_to_le16(rnbd_dev_get_max_segs(rnbd_dev));
 534         rsp->max_hw_sectors =
 535                 cpu_to_le32(rnbd_dev_get_max_hw_sects(rnbd_dev));
 536         rsp->max_write_same_sectors =
 537                 cpu_to_le32(bdev_write_same(rnbd_dev->bdev));
 538         rsp->max_discard_sectors =
 539                 cpu_to_le32(rnbd_dev_get_max_discard_sects(rnbd_dev));
 540         rsp->discard_granularity =
 541                 cpu_to_le32(rnbd_dev_get_discard_granularity(rnbd_dev));
 542         rsp->discard_alignment =
 543                 cpu_to_le32(rnbd_dev_get_discard_alignment(rnbd_dev));
 544         rsp->secure_discard =
 545                 cpu_to_le16(rnbd_dev_get_secure_discard(rnbd_dev));
 546         rsp->rotational =
 547                 !blk_queue_nonrot(bdev_get_queue(rnbd_dev->bdev));
 548 }
 549
 550 static struct rnbd_srv_sess_dev *
 551 rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess,
 552                               const struct rnbd_msg_open *open_msg,
 553                               struct rnbd_dev *rnbd_dev, fmode_t open_flags,
 554                               struct rnbd_srv_dev *srv_dev)
 555 {
 556         struct rnbd_srv_sess_dev *sdev = rnbd_sess_dev_alloc(srv_sess);
 557
 558         if (IS_ERR(sdev))
 559                 return sdev;
 560
 561         kref_init(&sdev->kref);
 562
 563         strlcpy(sdev->pathname, open_msg->dev_name, sizeof(sdev->pathname));
 564
 565         sdev->rnbd_dev          = rnbd_dev;
 566         sdev->sess              = srv_sess;
 567         sdev->dev               = srv_dev;
 568         sdev->open_flags        = open_flags;
 569         sdev->access_mode       = open_msg->access_mode;
 570
 571         return sdev;
 572 }
 573
 574 static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess,
 575                                      const char *dev_name)
 576 {
 577         char *full_path;
 578         char *a, *b;
 579
 580         full_path = kmalloc(PATH_MAX, GFP_KERNEL);
 581         if (!full_path)
 582                 return ERR_PTR(-ENOMEM);
 583
 584         /*
 585          * Replace %SESSNAME% with a real session name in order to
 586          * create device namespace.
 587          */
 588         a = strnstr(dev_search_path, "%SESSNAME%", sizeof(dev_search_path));
 589         if (a) {
 590                 int len = a - dev_search_path;
 591
 592                 len = snprintf(full_path, PATH_MAX, "%.*s/%s/%s", len,
 593                                dev_search_path, srv_sess->sessname, dev_name);
 594                 if (len >= PATH_MAX) {
 595                         pr_err("Too long path: %s, %s, %s\n",
 596                                dev_search_path, srv_sess->sessname, dev_name);
 597                         kfree(full_path);
 598                         return ERR_PTR(-EINVAL);
 599                 }
 600         } else {
 601                 snprintf(full_path, PATH_MAX, "%s/%s",
 602                          dev_search_path, dev_name);
 603         }
 604
 605         /* eliminitate duplicated slashes */
 606         a = strchr(full_path, '/');
 607         b = a;
 608         while (*b != '\0') {
 609                 if (*b == '/' && *a == '/') {
 610                         b++;
 611                 } else {
 612                         a++;
 613                         *a = *b;
 614                         b++;
 615                 }
 616         }
 617         a++;
 618         *a = '\0';
 619
 620         return full_path;
 621 }
 622
 623 static int process_msg_sess_info(struct rtrs_srv *rtrs,
 624                                  struct rnbd_srv_session *srv_sess,
 625                                  const void *msg, size_t len,
 626                                  void *data, size_t datalen)
 627 {
 628         const struct rnbd_msg_sess_info *sess_info_msg = msg;
 629         struct rnbd_msg_sess_info_rsp *rsp = data;
 630
 631         srv_sess->ver = min_t(u8, sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
 632         pr_debug("Session %s using protocol version %d (client version: %d, server version: %d)\n",
 633                  srv_sess->sessname, srv_sess->ver,
 634                  sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
 635
 636         rsp->hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO_RSP);
 637         rsp->ver = srv_sess->ver;
 638
 639         return 0;
 640 }
 641
 642 /**
 643  * find_srv_sess_dev() - a dev is already opened by this name
 644  * @srv_sess:   the session to search.
 645  * @dev_name:   string containing the name of the device.
 646  *
 647  * Return struct rnbd_srv_sess_dev if srv_sess already opened the dev_name
 648  * NULL if the session didn't open the device yet.
 649  */
 650 static struct rnbd_srv_sess_dev *
 651 find_srv_sess_dev(struct rnbd_srv_session *srv_sess, const char *dev_name)
 652 {
 653         struct rnbd_srv_sess_dev *sess_dev;
 654
 655         if (list_empty(&srv_sess->sess_dev_list))
 656                 return NULL;
 657
 658         list_for_each_entry(sess_dev, &srv_sess->sess_dev_list, sess_list)
 659                 if (!strcmp(sess_dev->pathname, dev_name))
 660                         return sess_dev;
 661
 662         return NULL;
 663 }
 664
 665 static int process_msg_open(struct rtrs_srv *rtrs,
 666                             struct rnbd_srv_session *srv_sess,
 667                             const void *msg, size_t len,
 668                             void *data, size_t datalen)
 669 {
 670         int ret;
 671         struct rnbd_srv_dev *srv_dev;
 672         struct rnbd_srv_sess_dev *srv_sess_dev;
 673         const struct rnbd_msg_open *open_msg = msg;
 674         fmode_t open_flags;
 675         char *full_path;
 676         struct rnbd_dev *rnbd_dev;
 677         struct rnbd_msg_open_rsp *rsp = data;
 678
 679         pr_debug("Open message received: session='%s' path='%s' access_mode=%d\n",
 680                  srv_sess->sessname, open_msg->dev_name,
 681                  open_msg->access_mode);
 682         open_flags = FMODE_READ;
 683         if (open_msg->access_mode != RNBD_ACCESS_RO)
 684                 open_flags |= FMODE_WRITE;
 685
 686         mutex_lock(&srv_sess->lock);
 687
 688         srv_sess_dev = find_srv_sess_dev(srv_sess, open_msg->dev_name);
 689         if (srv_sess_dev)
 690                 goto fill_response;
 691
 692         if ((strlen(dev_search_path) + strlen(open_msg->dev_name))
 693             >= PATH_MAX) {
 694                 pr_err("Opening device for session %s failed, device path too long. '%s/%s' is longer than PATH_MAX (%d)\n",
 695                        srv_sess->sessname, dev_search_path, open_msg->dev_name,
 696                        PATH_MAX);
 697                 ret = -EINVAL;
 698                 goto reject;
 699         }
 700         if (strstr(open_msg->dev_name, "..")) {
 701                 pr_err("Opening device for session %s failed, device path %s contains relative path ..\n",
 702                        srv_sess->sessname, open_msg->dev_name);
 703                 ret = -EINVAL;
 704                 goto reject;
 705         }
 706         full_path = rnbd_srv_get_full_path(srv_sess, open_msg->dev_name);
 707         if (IS_ERR(full_path)) {
 708                 ret = PTR_ERR(full_path);
 709                 pr_err("Opening device '%s' for client %s failed, failed to get device full path, err: %d\n",
 710                        open_msg->dev_name, srv_sess->sessname, ret);
 711                 goto reject;
 712         }
 713
 714         rnbd_dev = rnbd_dev_open(full_path, open_flags,
 715                                  &srv_sess->sess_bio_set);
 716         if (IS_ERR(rnbd_dev)) {
 717                 pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %ld\n",
 718                        full_path, srv_sess->sessname, PTR_ERR(rnbd_dev));
 719                 ret = PTR_ERR(rnbd_dev);
 720                 goto free_path;
 721         }
 722
 723         srv_dev = rnbd_srv_get_or_create_srv_dev(rnbd_dev, srv_sess,
 724                                                   open_msg->access_mode);
 725         if (IS_ERR(srv_dev)) {
 726                 pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %ld\n",
 727                        full_path, srv_sess->sessname, PTR_ERR(srv_dev));
 728                 ret = PTR_ERR(srv_dev);
 729                 goto rnbd_dev_close;
 730         }
 731
 732         srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
 733                                                      rnbd_dev, open_flags,
 734                                                      srv_dev);
 735         if (IS_ERR(srv_sess_dev)) {
 736                 pr_err("Opening device '%s' on session %s failed, creating sess_dev failed, err: %ld\n",
 737                        full_path, srv_sess->sessname, PTR_ERR(srv_sess_dev));
 738                 ret = PTR_ERR(srv_sess_dev);
 739                 goto srv_dev_put;
 740         }
 741
 742         /* Create the srv_dev sysfs files if they haven't been created yet. The
 743          * reason to delay the creation is not to create the sysfs files before
 744          * we are sure the device can be opened.
 745          */
 746         mutex_lock(&srv_dev->lock);
 747         if (!srv_dev->dev_kobj.state_in_sysfs) {
 748                 ret = rnbd_srv_create_dev_sysfs(srv_dev, rnbd_dev->bdev,
 749                                                  rnbd_dev->name);
 750                 if (ret) {
 751                         mutex_unlock(&srv_dev->lock);
 752                         rnbd_srv_err(srv_sess_dev,
 753                                       "Opening device failed, failed to create device sysfs files, err: %d\n",
 754                                       ret);
 755                         goto free_srv_sess_dev;
 756                 }
 757         }
 758
 759         ret = rnbd_srv_create_dev_session_sysfs(srv_sess_dev);
 760         if (ret) {
 761                 mutex_unlock(&srv_dev->lock);
 762                 rnbd_srv_err(srv_sess_dev,
 763                               "Opening device failed, failed to create dev client sysfs files, err: %d\n",
 764                               ret);
 765                 goto free_srv_sess_dev;
 766         }
 767
 768         list_add(&srv_sess_dev->dev_list, &srv_dev->sess_dev_list);
 769         mutex_unlock(&srv_dev->lock);
 770
 771         list_add(&srv_sess_dev->sess_list, &srv_sess->sess_dev_list);
 772
 773         rnbd_srv_info(srv_sess_dev, "Opened device '%s'\n", srv_dev->id);
 774
 775         kfree(full_path);
 776
 777 fill_response:
 778         rnbd_srv_fill_msg_open_rsp(rsp, srv_sess_dev);
 779         mutex_unlock(&srv_sess->lock);
 780         return 0;
 781
 782 free_srv_sess_dev:
 783         xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id);
 784         synchronize_rcu();
 785         kfree(srv_sess_dev);
 786 srv_dev_put:
 787         if (open_msg->access_mode != RNBD_ACCESS_RO) {
 788                 mutex_lock(&srv_dev->lock);
 789                 srv_dev->open_write_cnt--;
 790                 mutex_unlock(&srv_dev->lock);
 791         }
 792         rnbd_put_srv_dev(srv_dev);
 793 rnbd_dev_close:
 794         rnbd_dev_close(rnbd_dev);
 795 free_path:
 796         kfree(full_path);
 797 reject:
 798         mutex_unlock(&srv_sess->lock);
 799         return ret;
 800 }
 801
 802 static struct rtrs_srv_ctx *rtrs_ctx;
 803
 804 static struct rtrs_srv_ops rtrs_ops;
 805 static int __init rnbd_srv_init_module(void)
 806 {
 807         int err;
 808
 809         BUILD_BUG_ON(sizeof(struct rnbd_msg_hdr) != 4);
 810         BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info) != 36);
 811         BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info_rsp) != 36);
 812         BUILD_BUG_ON(sizeof(struct rnbd_msg_open) != 264);
 813         BUILD_BUG_ON(sizeof(struct rnbd_msg_close) != 8);
 814         BUILD_BUG_ON(sizeof(struct rnbd_msg_open_rsp) != 56);
 815         rtrs_ops = (struct rtrs_srv_ops) {
 816                 .rdma_ev = rnbd_srv_rdma_ev,
 817                 .link_ev = rnbd_srv_link_ev,
 818         };
 819         rtrs_ctx = rtrs_srv_open(&rtrs_ops, port_nr);
 820         if (IS_ERR(rtrs_ctx)) {
 821                 err = PTR_ERR(rtrs_ctx);
 822                 pr_err("rtrs_srv_open(), err: %d\n", err);
 823                 return err;
 824         }
 825
 826         err = rnbd_srv_create_sysfs_files();
 827         if (err) {
 828                 pr_err("rnbd_srv_create_sysfs_files(), err: %d\n", err);
 829                 rtrs_srv_close(rtrs_ctx);
 830                 return err;
 831         }
 832
 833         return 0;
 834 }
 835
 836 static void __exit rnbd_srv_cleanup_module(void)
 837 {
 838         rtrs_srv_close(rtrs_ctx);
 839         WARN_ON(!list_empty(&sess_list));
 840         rnbd_srv_destroy_sysfs_files();
 841 }
 842
 843 module_init(rnbd_srv_init_module);
 844 module_exit(rnbd_srv_cleanup_module);