linux/drivers/block/rnbd/rnbd-srv.c
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   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
  18MODULE_DESCRIPTION("RDMA Network Block Device Server");
  19MODULE_LICENSE("GPL");
  20
  21static u16 port_nr = RTRS_PORT;
  22
  23module_param_named(port_nr, port_nr, ushort, 0444);
  24MODULE_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
  30static char dev_search_path[PATH_MAX] = DEFAULT_DEV_SEARCH_PATH;
  31
  32static 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
  47static struct kparam_string dev_search_path_kparam_str = {
  48        .maxlen = sizeof(dev_search_path),
  49        .string = dev_search_path
  50};
  51
  52static const struct kernel_param_ops dev_search_path_ops = {
  53        .set    = dev_search_path_set,
  54        .get    = param_get_string,
  55};
  56
  57module_param_cb(dev_search_path, &dev_search_path_ops,
  58                &dev_search_path_kparam_str, 0444);
  59MODULE_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
  63static DEFINE_MUTEX(sess_lock);
  64static DEFINE_SPINLOCK(dev_lock);
  65
  66static LIST_HEAD(sess_list);
  67static LIST_HEAD(dev_list);
  68
  69struct rnbd_io_private {
  70        struct rtrs_srv_op              *id;
  71        struct rnbd_srv_sess_dev        *sess_dev;
  72};
  73
  74static 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
  82static 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
  87void 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
  99static struct rnbd_srv_sess_dev *
 100rnbd_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
 117static 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
 173sess_dev_put:
 174        rnbd_put_sess_dev(sess_dev);
 175err:
 176        kfree(priv);
 177        return err;
 178}
 179
 180static 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
 202static void rnbd_put_srv_dev(struct rnbd_srv_dev *dev)
 203{
 204        kref_put(&dev->kref, destroy_device);
 205}
 206
 207void 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
 239static 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
 252out:
 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
 266static int create_sess(struct rtrs_srv *rtrs)
 267{
 268        struct rnbd_srv_session *srv_sess;
 269        char sessname[NAME_MAX];
 270        int err;
 271
 272        err = rtrs_srv_get_sess_name(rtrs, sessname, sizeof(sessname));
 273        if (err) {
 274                pr_err("rtrs_srv_get_sess_name(%s): %d\n", sessname, 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 session %s failed\n",
 288                       sessname);
 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, sessname, sizeof(srv_sess->sessname));
 302
 303        rtrs_srv_set_sess_priv(rtrs, srv_sess);
 304
 305        return 0;
 306}
 307
 308static 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
 331void 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        sess_dev->keep_id = true;
 337        /* It is already started to close by client's close message. */
 338        if (!mutex_trylock(&sess->lock))
 339                return;
 340        /* first remove sysfs itself to avoid deadlock */
 341        sysfs_remove_file_self(&sess_dev->kobj, &attr->attr);
 342        rnbd_srv_destroy_dev_session_sysfs(sess_dev);
 343        mutex_unlock(&sess->lock);
 344}
 345
 346static int process_msg_close(struct rnbd_srv_session *srv_sess,
 347                             void *data, size_t datalen, const void *usr,
 348                             size_t usrlen)
 349{
 350        const struct rnbd_msg_close *close_msg = usr;
 351        struct rnbd_srv_sess_dev *sess_dev;
 352
 353        sess_dev = rnbd_get_sess_dev(le32_to_cpu(close_msg->device_id),
 354                                      srv_sess);
 355        if (IS_ERR(sess_dev))
 356                return 0;
 357
 358        rnbd_put_sess_dev(sess_dev);
 359        mutex_lock(&srv_sess->lock);
 360        rnbd_srv_destroy_dev_session_sysfs(sess_dev);
 361        mutex_unlock(&srv_sess->lock);
 362        return 0;
 363}
 364
 365static int process_msg_open(struct rnbd_srv_session *srv_sess,
 366                            const void *msg, size_t len,
 367                            void *data, size_t datalen);
 368
 369static int process_msg_sess_info(struct rnbd_srv_session *srv_sess,
 370                                 const void *msg, size_t len,
 371                                 void *data, size_t datalen);
 372
 373static int rnbd_srv_rdma_ev(void *priv,
 374                            struct rtrs_srv_op *id, int dir,
 375                            void *data, size_t datalen, const void *usr,
 376                            size_t usrlen)
 377{
 378        struct rnbd_srv_session *srv_sess = priv;
 379        const struct rnbd_msg_hdr *hdr = usr;
 380        int ret = 0;
 381        u16 type;
 382
 383        if (WARN_ON_ONCE(!srv_sess))
 384                return -ENODEV;
 385
 386        type = le16_to_cpu(hdr->type);
 387
 388        switch (type) {
 389        case RNBD_MSG_IO:
 390                return process_rdma(srv_sess, id, data, datalen, usr, usrlen);
 391        case RNBD_MSG_CLOSE:
 392                ret = process_msg_close(srv_sess, data, datalen, usr, usrlen);
 393                break;
 394        case RNBD_MSG_OPEN:
 395                ret = process_msg_open(srv_sess, usr, usrlen, data, datalen);
 396                break;
 397        case RNBD_MSG_SESS_INFO:
 398                ret = process_msg_sess_info(srv_sess, usr, usrlen, data,
 399                                            datalen);
 400                break;
 401        default:
 402                pr_warn("Received unexpected message type %d with dir %d from session %s\n",
 403                        type, dir, srv_sess->sessname);
 404                return -EINVAL;
 405        }
 406
 407        rtrs_srv_resp_rdma(id, ret);
 408        return 0;
 409}
 410
 411static struct rnbd_srv_sess_dev
 412*rnbd_sess_dev_alloc(struct rnbd_srv_session *srv_sess)
 413{
 414        struct rnbd_srv_sess_dev *sess_dev;
 415        int error;
 416
 417        sess_dev = kzalloc(sizeof(*sess_dev), GFP_KERNEL);
 418        if (!sess_dev)
 419                return ERR_PTR(-ENOMEM);
 420
 421        error = xa_alloc(&srv_sess->index_idr, &sess_dev->device_id, sess_dev,
 422                         xa_limit_32b, GFP_NOWAIT);
 423        if (error < 0) {
 424                pr_warn("Allocating idr failed, err: %d\n", error);
 425                kfree(sess_dev);
 426                return ERR_PTR(error);
 427        }
 428
 429        return sess_dev;
 430}
 431
 432static struct rnbd_srv_dev *rnbd_srv_init_srv_dev(const char *id)
 433{
 434        struct rnbd_srv_dev *dev;
 435
 436        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 437        if (!dev)
 438                return ERR_PTR(-ENOMEM);
 439
 440        strscpy(dev->id, id, sizeof(dev->id));
 441        kref_init(&dev->kref);
 442        INIT_LIST_HEAD(&dev->sess_dev_list);
 443        mutex_init(&dev->lock);
 444
 445        return dev;
 446}
 447
 448static struct rnbd_srv_dev *
 449rnbd_srv_find_or_add_srv_dev(struct rnbd_srv_dev *new_dev)
 450{
 451        struct rnbd_srv_dev *dev;
 452
 453        spin_lock(&dev_lock);
 454        list_for_each_entry(dev, &dev_list, list) {
 455                if (!strncmp(dev->id, new_dev->id, sizeof(dev->id))) {
 456                        if (!kref_get_unless_zero(&dev->kref))
 457                                /*
 458                                 * We lost the race, device is almost dead.
 459                                 *  Continue traversing to find a valid one.
 460                                 */
 461                                continue;
 462                        spin_unlock(&dev_lock);
 463                        return dev;
 464                }
 465        }
 466        list_add(&new_dev->list, &dev_list);
 467        spin_unlock(&dev_lock);
 468
 469        return new_dev;
 470}
 471
 472static int rnbd_srv_check_update_open_perm(struct rnbd_srv_dev *srv_dev,
 473                                            struct rnbd_srv_session *srv_sess,
 474                                            enum rnbd_access_mode access_mode)
 475{
 476        int ret = -EPERM;
 477
 478        mutex_lock(&srv_dev->lock);
 479
 480        switch (access_mode) {
 481        case RNBD_ACCESS_RO:
 482                ret = 0;
 483                break;
 484        case RNBD_ACCESS_RW:
 485                if (srv_dev->open_write_cnt == 0)  {
 486                        srv_dev->open_write_cnt++;
 487                        ret = 0;
 488                } else {
 489                        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",
 490                               srv_dev->id, srv_sess->sessname,
 491                               srv_dev->open_write_cnt,
 492                               rnbd_access_mode_str(access_mode));
 493                }
 494                break;
 495        case RNBD_ACCESS_MIGRATION:
 496                if (srv_dev->open_write_cnt < 2) {
 497                        srv_dev->open_write_cnt++;
 498                        ret = 0;
 499                } else {
 500                        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",
 501                               srv_dev->id, srv_sess->sessname,
 502                               srv_dev->open_write_cnt,
 503                               rnbd_access_mode_str(access_mode));
 504                }
 505                break;
 506        default:
 507                pr_err("Received mapping request for device '%s' on session %s with invalid access mode: %d\n",
 508                       srv_dev->id, srv_sess->sessname, access_mode);
 509                ret = -EINVAL;
 510        }
 511
 512        mutex_unlock(&srv_dev->lock);
 513
 514        return ret;
 515}
 516
 517static struct rnbd_srv_dev *
 518rnbd_srv_get_or_create_srv_dev(struct rnbd_dev *rnbd_dev,
 519                                struct rnbd_srv_session *srv_sess,
 520                                enum rnbd_access_mode access_mode)
 521{
 522        int ret;
 523        struct rnbd_srv_dev *new_dev, *dev;
 524
 525        new_dev = rnbd_srv_init_srv_dev(rnbd_dev->name);
 526        if (IS_ERR(new_dev))
 527                return new_dev;
 528
 529        dev = rnbd_srv_find_or_add_srv_dev(new_dev);
 530        if (dev != new_dev)
 531                kfree(new_dev);
 532
 533        ret = rnbd_srv_check_update_open_perm(dev, srv_sess, access_mode);
 534        if (ret) {
 535                rnbd_put_srv_dev(dev);
 536                return ERR_PTR(ret);
 537        }
 538
 539        return dev;
 540}
 541
 542static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
 543                                        struct rnbd_srv_sess_dev *sess_dev)
 544{
 545        struct rnbd_dev *rnbd_dev = sess_dev->rnbd_dev;
 546        struct request_queue *q = bdev_get_queue(rnbd_dev->bdev);
 547
 548        rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP);
 549        rsp->device_id =
 550                cpu_to_le32(sess_dev->device_id);
 551        rsp->nsectors =
 552                cpu_to_le64(get_capacity(rnbd_dev->bdev->bd_disk));
 553        rsp->logical_block_size =
 554                cpu_to_le16(bdev_logical_block_size(rnbd_dev->bdev));
 555        rsp->physical_block_size =
 556                cpu_to_le16(bdev_physical_block_size(rnbd_dev->bdev));
 557        rsp->max_segments =
 558                cpu_to_le16(rnbd_dev_get_max_segs(rnbd_dev));
 559        rsp->max_hw_sectors =
 560                cpu_to_le32(rnbd_dev_get_max_hw_sects(rnbd_dev));
 561        rsp->max_write_same_sectors =
 562                cpu_to_le32(bdev_write_same(rnbd_dev->bdev));
 563        rsp->max_discard_sectors =
 564                cpu_to_le32(rnbd_dev_get_max_discard_sects(rnbd_dev));
 565        rsp->discard_granularity =
 566                cpu_to_le32(rnbd_dev_get_discard_granularity(rnbd_dev));
 567        rsp->discard_alignment =
 568                cpu_to_le32(rnbd_dev_get_discard_alignment(rnbd_dev));
 569        rsp->secure_discard =
 570                cpu_to_le16(rnbd_dev_get_secure_discard(rnbd_dev));
 571        rsp->rotational = !blk_queue_nonrot(q);
 572        rsp->cache_policy = 0;
 573        if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 574                rsp->cache_policy |= RNBD_WRITEBACK;
 575        if (blk_queue_fua(q))
 576                rsp->cache_policy |= RNBD_FUA;
 577}
 578
 579static struct rnbd_srv_sess_dev *
 580rnbd_srv_create_set_sess_dev(struct rnbd_srv_session *srv_sess,
 581                              const struct rnbd_msg_open *open_msg,
 582                              struct rnbd_dev *rnbd_dev, fmode_t open_flags,
 583                              struct rnbd_srv_dev *srv_dev)
 584{
 585        struct rnbd_srv_sess_dev *sdev = rnbd_sess_dev_alloc(srv_sess);
 586
 587        if (IS_ERR(sdev))
 588                return sdev;
 589
 590        kref_init(&sdev->kref);
 591
 592        strscpy(sdev->pathname, open_msg->dev_name, sizeof(sdev->pathname));
 593
 594        sdev->rnbd_dev          = rnbd_dev;
 595        sdev->sess              = srv_sess;
 596        sdev->dev               = srv_dev;
 597        sdev->open_flags        = open_flags;
 598        sdev->access_mode       = open_msg->access_mode;
 599
 600        return sdev;
 601}
 602
 603static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess,
 604                                     const char *dev_name)
 605{
 606        char *full_path;
 607        char *a, *b;
 608
 609        full_path = kmalloc(PATH_MAX, GFP_KERNEL);
 610        if (!full_path)
 611                return ERR_PTR(-ENOMEM);
 612
 613        /*
 614         * Replace %SESSNAME% with a real session name in order to
 615         * create device namespace.
 616         */
 617        a = strnstr(dev_search_path, "%SESSNAME%", sizeof(dev_search_path));
 618        if (a) {
 619                int len = a - dev_search_path;
 620
 621                len = snprintf(full_path, PATH_MAX, "%.*s/%s/%s", len,
 622                               dev_search_path, srv_sess->sessname, dev_name);
 623                if (len >= PATH_MAX) {
 624                        pr_err("Too long path: %s, %s, %s\n",
 625                               dev_search_path, srv_sess->sessname, dev_name);
 626                        kfree(full_path);
 627                        return ERR_PTR(-EINVAL);
 628                }
 629        } else {
 630                snprintf(full_path, PATH_MAX, "%s/%s",
 631                         dev_search_path, dev_name);
 632        }
 633
 634        /* eliminitate duplicated slashes */
 635        a = strchr(full_path, '/');
 636        b = a;
 637        while (*b != '\0') {
 638                if (*b == '/' && *a == '/') {
 639                        b++;
 640                } else {
 641                        a++;
 642                        *a = *b;
 643                        b++;
 644                }
 645        }
 646        a++;
 647        *a = '\0';
 648
 649        return full_path;
 650}
 651
 652static int 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        pr_debug("Session %s using protocol version %d (client version: %d, server version: %d)\n",
 661                 srv_sess->sessname, srv_sess->ver,
 662                 sess_info_msg->ver, RNBD_PROTO_VER_MAJOR);
 663
 664        rsp->hdr.type = cpu_to_le16(RNBD_MSG_SESS_INFO_RSP);
 665        rsp->ver = srv_sess->ver;
 666
 667        return 0;
 668}
 669
 670/**
 671 * find_srv_sess_dev() - a dev is already opened by this name
 672 * @srv_sess:   the session to search.
 673 * @dev_name:   string containing the name of the device.
 674 *
 675 * Return struct rnbd_srv_sess_dev if srv_sess already opened the dev_name
 676 * NULL if the session didn't open the device yet.
 677 */
 678static struct rnbd_srv_sess_dev *
 679find_srv_sess_dev(struct rnbd_srv_session *srv_sess, const char *dev_name)
 680{
 681        struct rnbd_srv_sess_dev *sess_dev;
 682
 683        if (list_empty(&srv_sess->sess_dev_list))
 684                return NULL;
 685
 686        list_for_each_entry(sess_dev, &srv_sess->sess_dev_list, sess_list)
 687                if (!strcmp(sess_dev->pathname, dev_name))
 688                        return sess_dev;
 689
 690        return NULL;
 691}
 692
 693static int process_msg_open(struct rnbd_srv_session *srv_sess,
 694                            const void *msg, size_t len,
 695                            void *data, size_t datalen)
 696{
 697        int ret;
 698        struct rnbd_srv_dev *srv_dev;
 699        struct rnbd_srv_sess_dev *srv_sess_dev;
 700        const struct rnbd_msg_open *open_msg = msg;
 701        fmode_t open_flags;
 702        char *full_path;
 703        struct rnbd_dev *rnbd_dev;
 704        struct rnbd_msg_open_rsp *rsp = data;
 705
 706        pr_debug("Open message received: session='%s' path='%s' access_mode=%d\n",
 707                 srv_sess->sessname, open_msg->dev_name,
 708                 open_msg->access_mode);
 709        open_flags = FMODE_READ;
 710        if (open_msg->access_mode != RNBD_ACCESS_RO)
 711                open_flags |= FMODE_WRITE;
 712
 713        mutex_lock(&srv_sess->lock);
 714
 715        srv_sess_dev = find_srv_sess_dev(srv_sess, open_msg->dev_name);
 716        if (srv_sess_dev)
 717                goto fill_response;
 718
 719        if ((strlen(dev_search_path) + strlen(open_msg->dev_name))
 720            >= PATH_MAX) {
 721                pr_err("Opening device for session %s failed, device path too long. '%s/%s' is longer than PATH_MAX (%d)\n",
 722                       srv_sess->sessname, dev_search_path, open_msg->dev_name,
 723                       PATH_MAX);
 724                ret = -EINVAL;
 725                goto reject;
 726        }
 727        if (strstr(open_msg->dev_name, "..")) {
 728                pr_err("Opening device for session %s failed, device path %s contains relative path ..\n",
 729                       srv_sess->sessname, open_msg->dev_name);
 730                ret = -EINVAL;
 731                goto reject;
 732        }
 733        full_path = rnbd_srv_get_full_path(srv_sess, open_msg->dev_name);
 734        if (IS_ERR(full_path)) {
 735                ret = PTR_ERR(full_path);
 736                pr_err("Opening device '%s' for client %s failed, failed to get device full path, err: %d\n",
 737                       open_msg->dev_name, srv_sess->sessname, ret);
 738                goto reject;
 739        }
 740
 741        rnbd_dev = rnbd_dev_open(full_path, open_flags,
 742                                 &srv_sess->sess_bio_set);
 743        if (IS_ERR(rnbd_dev)) {
 744                pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %ld\n",
 745                       full_path, srv_sess->sessname, PTR_ERR(rnbd_dev));
 746                ret = PTR_ERR(rnbd_dev);
 747                goto free_path;
 748        }
 749
 750        srv_dev = rnbd_srv_get_or_create_srv_dev(rnbd_dev, srv_sess,
 751                                                  open_msg->access_mode);
 752        if (IS_ERR(srv_dev)) {
 753                pr_err("Opening device '%s' on session %s failed, creating srv_dev failed, err: %ld\n",
 754                       full_path, srv_sess->sessname, PTR_ERR(srv_dev));
 755                ret = PTR_ERR(srv_dev);
 756                goto rnbd_dev_close;
 757        }
 758
 759        srv_sess_dev = rnbd_srv_create_set_sess_dev(srv_sess, open_msg,
 760                                                     rnbd_dev, open_flags,
 761                                                     srv_dev);
 762        if (IS_ERR(srv_sess_dev)) {
 763                pr_err("Opening device '%s' on session %s failed, creating sess_dev failed, err: %ld\n",
 764                       full_path, srv_sess->sessname, PTR_ERR(srv_sess_dev));
 765                ret = PTR_ERR(srv_sess_dev);
 766                goto srv_dev_put;
 767        }
 768
 769        /* Create the srv_dev sysfs files if they haven't been created yet. The
 770         * reason to delay the creation is not to create the sysfs files before
 771         * we are sure the device can be opened.
 772         */
 773        mutex_lock(&srv_dev->lock);
 774        if (!srv_dev->dev_kobj.state_in_sysfs) {
 775                ret = rnbd_srv_create_dev_sysfs(srv_dev, rnbd_dev->bdev,
 776                                                 rnbd_dev->name);
 777                if (ret) {
 778                        mutex_unlock(&srv_dev->lock);
 779                        rnbd_srv_err(srv_sess_dev,
 780                                      "Opening device failed, failed to create device sysfs files, err: %d\n",
 781                                      ret);
 782                        goto free_srv_sess_dev;
 783                }
 784        }
 785
 786        ret = rnbd_srv_create_dev_session_sysfs(srv_sess_dev);
 787        if (ret) {
 788                mutex_unlock(&srv_dev->lock);
 789                rnbd_srv_err(srv_sess_dev,
 790                              "Opening device failed, failed to create dev client sysfs files, err: %d\n",
 791                              ret);
 792                goto free_srv_sess_dev;
 793        }
 794
 795        list_add(&srv_sess_dev->dev_list, &srv_dev->sess_dev_list);
 796        mutex_unlock(&srv_dev->lock);
 797
 798        list_add(&srv_sess_dev->sess_list, &srv_sess->sess_dev_list);
 799
 800        rnbd_srv_info(srv_sess_dev, "Opened device '%s'\n", srv_dev->id);
 801
 802        kfree(full_path);
 803
 804fill_response:
 805        rnbd_srv_fill_msg_open_rsp(rsp, srv_sess_dev);
 806        mutex_unlock(&srv_sess->lock);
 807        return 0;
 808
 809free_srv_sess_dev:
 810        xa_erase(&srv_sess->index_idr, srv_sess_dev->device_id);
 811        synchronize_rcu();
 812        kfree(srv_sess_dev);
 813srv_dev_put:
 814        if (open_msg->access_mode != RNBD_ACCESS_RO) {
 815                mutex_lock(&srv_dev->lock);
 816                srv_dev->open_write_cnt--;
 817                mutex_unlock(&srv_dev->lock);
 818        }
 819        rnbd_put_srv_dev(srv_dev);
 820rnbd_dev_close:
 821        rnbd_dev_close(rnbd_dev);
 822free_path:
 823        kfree(full_path);
 824reject:
 825        mutex_unlock(&srv_sess->lock);
 826        return ret;
 827}
 828
 829static struct rtrs_srv_ctx *rtrs_ctx;
 830
 831static struct rtrs_srv_ops rtrs_ops;
 832static int __init rnbd_srv_init_module(void)
 833{
 834        int err;
 835
 836        BUILD_BUG_ON(sizeof(struct rnbd_msg_hdr) != 4);
 837        BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info) != 36);
 838        BUILD_BUG_ON(sizeof(struct rnbd_msg_sess_info_rsp) != 36);
 839        BUILD_BUG_ON(sizeof(struct rnbd_msg_open) != 264);
 840        BUILD_BUG_ON(sizeof(struct rnbd_msg_close) != 8);
 841        BUILD_BUG_ON(sizeof(struct rnbd_msg_open_rsp) != 56);
 842        rtrs_ops = (struct rtrs_srv_ops) {
 843                .rdma_ev = rnbd_srv_rdma_ev,
 844                .link_ev = rnbd_srv_link_ev,
 845        };
 846        rtrs_ctx = rtrs_srv_open(&rtrs_ops, port_nr);
 847        if (IS_ERR(rtrs_ctx)) {
 848                err = PTR_ERR(rtrs_ctx);
 849                pr_err("rtrs_srv_open(), err: %d\n", err);
 850                return err;
 851        }
 852
 853        err = rnbd_srv_create_sysfs_files();
 854        if (err) {
 855                pr_err("rnbd_srv_create_sysfs_files(), err: %d\n", err);
 856                rtrs_srv_close(rtrs_ctx);
 857                return err;
 858        }
 859
 860        return 0;
 861}
 862
 863static void __exit rnbd_srv_cleanup_module(void)
 864{
 865        rtrs_srv_close(rtrs_ctx);
 866        WARN_ON(!list_empty(&sess_list));
 867        rnbd_srv_destroy_sysfs_files();
 868}
 869
 870module_init(rnbd_srv_init_module);
 871module_exit(rnbd_srv_cleanup_module);
 872