fs/dlm/user.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2006-2010 Red Hat, Inc.  All rights reserved.
   4  */
   5
   6 #include <linux/miscdevice.h>
   7 #include <linux/init.h>
   8 #include <linux/wait.h>
   9 #include <linux/file.h>
  10 #include <linux/fs.h>
  11 #include <linux/poll.h>
  12 #include <linux/signal.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/dlm.h>
  15 #include <linux/dlm_device.h>
  16 #include <linux/slab.h>
  17 #include <linux/sched/signal.h>
  18
  19 #include <trace/events/dlm.h>
  20
  21 #include "dlm_internal.h"
  22 #include "lockspace.h"
  23 #include "lock.h"
  24 #include "lvb_table.h"
  25 #include "user.h"
  26 #include "ast.h"
  27 #include "config.h"
  28 #include "memory.h"
  29
  30 static const char name_prefix[] = "dlm";
  31 static const struct file_operations device_fops;
  32 static atomic_t dlm_monitor_opened;
  33 static int dlm_monitor_unused = 1;
  34
  35 #ifdef CONFIG_COMPAT
  36
  37 struct dlm_lock_params32 {
  38         __u8 mode;
  39         __u8 namelen;
  40         __u16 unused;
  41         __u32 flags;
  42         __u32 lkid;
  43         __u32 parent;
  44         __u64 xid;
  45         __u64 timeout;
  46         __u32 castparam;
  47         __u32 castaddr;
  48         __u32 bastparam;
  49         __u32 bastaddr;
  50         __u32 lksb;
  51         char lvb[DLM_USER_LVB_LEN];
  52         char name[];
  53 };
  54
  55 struct dlm_write_request32 {
  56         __u32 version[3];
  57         __u8 cmd;
  58         __u8 is64bit;
  59         __u8 unused[2];
  60
  61         union  {
  62                 struct dlm_lock_params32 lock;
  63                 struct dlm_lspace_params lspace;
  64                 struct dlm_purge_params purge;
  65         } i;
  66 };
  67
  68 struct dlm_lksb32 {
  69         __u32 sb_status;
  70         __u32 sb_lkid;
  71         __u8 sb_flags;
  72         __u32 sb_lvbptr;
  73 };
  74
  75 struct dlm_lock_result32 {
  76         __u32 version[3];
  77         __u32 length;
  78         __u32 user_astaddr;
  79         __u32 user_astparam;
  80         __u32 user_lksb;
  81         struct dlm_lksb32 lksb;
  82         __u8 bast_mode;
  83         __u8 unused[3];
  84         /* Offsets may be zero if no data is present */
  85         __u32 lvb_offset;
  86 };
  87
  88 static void compat_input(struct dlm_write_request *kb,
  89                          struct dlm_write_request32 *kb32,
  90                          int namelen)
  91 {
  92         kb->version[0] = kb32->version[0];
  93         kb->version[1] = kb32->version[1];
  94         kb->version[2] = kb32->version[2];
  95
  96         kb->cmd = kb32->cmd;
  97         kb->is64bit = kb32->is64bit;
  98         if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
  99             kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
 100                 kb->i.lspace.flags = kb32->i.lspace.flags;
 101                 kb->i.lspace.minor = kb32->i.lspace.minor;
 102                 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
 103         } else if (kb->cmd == DLM_USER_PURGE) {
 104                 kb->i.purge.nodeid = kb32->i.purge.nodeid;
 105                 kb->i.purge.pid = kb32->i.purge.pid;
 106         } else {
 107                 kb->i.lock.mode = kb32->i.lock.mode;
 108                 kb->i.lock.namelen = kb32->i.lock.namelen;
 109                 kb->i.lock.flags = kb32->i.lock.flags;
 110                 kb->i.lock.lkid = kb32->i.lock.lkid;
 111                 kb->i.lock.parent = kb32->i.lock.parent;
 112                 kb->i.lock.xid = kb32->i.lock.xid;
 113                 kb->i.lock.timeout = kb32->i.lock.timeout;
 114                 kb->i.lock.castparam = (__user void *)(long)kb32->i.lock.castparam;
 115                 kb->i.lock.castaddr = (__user void *)(long)kb32->i.lock.castaddr;
 116                 kb->i.lock.bastparam = (__user void *)(long)kb32->i.lock.bastparam;
 117                 kb->i.lock.bastaddr = (__user void *)(long)kb32->i.lock.bastaddr;
 118                 kb->i.lock.lksb = (__user void *)(long)kb32->i.lock.lksb;
 119                 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
 120                 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
 121         }
 122 }
 123
 124 static void compat_output(struct dlm_lock_result *res,
 125                           struct dlm_lock_result32 *res32)
 126 {
 127         memset(res32, 0, sizeof(*res32));
 128
 129         res32->version[0] = res->version[0];
 130         res32->version[1] = res->version[1];
 131         res32->version[2] = res->version[2];
 132
 133         res32->user_astaddr = (__u32)(__force long)res->user_astaddr;
 134         res32->user_astparam = (__u32)(__force long)res->user_astparam;
 135         res32->user_lksb = (__u32)(__force long)res->user_lksb;
 136         res32->bast_mode = res->bast_mode;
 137
 138         res32->lvb_offset = res->lvb_offset;
 139         res32->length = res->length;
 140
 141         res32->lksb.sb_status = res->lksb.sb_status;
 142         res32->lksb.sb_flags = res->lksb.sb_flags;
 143         res32->lksb.sb_lkid = res->lksb.sb_lkid;
 144         res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr;
 145 }
 146 #endif
 147
 148 /* Figure out if this lock is at the end of its life and no longer
 149    available for the application to use.  The lkb still exists until
 150    the final ast is read.  A lock becomes EOL in three situations:
 151      1. a noqueue request fails with EAGAIN
 152      2. an unlock completes with EUNLOCK
 153      3. a cancel of a waiting request completes with ECANCEL/EDEADLK
 154    An EOL lock needs to be removed from the process's list of locks.
 155    And we can't allow any new operation on an EOL lock.  This is
 156    not related to the lifetime of the lkb struct which is managed
 157    entirely by refcount. */
 158
 159 static int lkb_is_endoflife(int mode, int status)
 160 {
 161         switch (status) {
 162         case -DLM_EUNLOCK:
 163                 return 1;
 164         case -DLM_ECANCEL:
 165         case -ETIMEDOUT:
 166         case -EDEADLK:
 167         case -EAGAIN:
 168                 if (mode == DLM_LOCK_IV)
 169                         return 1;
 170                 break;
 171         }
 172         return 0;
 173 }
 174
 175 /* we could possibly check if the cancel of an orphan has resulted in the lkb
 176    being removed and then remove that lkb from the orphans list and free it */
 177
 178 void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode,
 179                       int status, uint32_t sbflags)
 180 {
 181         struct dlm_ls *ls;
 182         struct dlm_user_args *ua;
 183         struct dlm_user_proc *proc;
 184         int rv;
 185
 186         if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
 187                 return;
 188
 189         ls = lkb->lkb_resource->res_ls;
 190         spin_lock(&ls->ls_clear_proc_locks);
 191
 192         /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
 193            can't be delivered.  For ORPHAN's, dlm_clear_proc_locks() freed
 194            lkb->ua so we can't try to use it.  This second check is necessary
 195            for cases where a completion ast is received for an operation that
 196            began before clear_proc_locks did its cancel/unlock. */
 197
 198         if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
 199                 goto out;
 200
 201         DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb););
 202         ua = lkb->lkb_ua;
 203         proc = ua->proc;
 204
 205         if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL)
 206                 goto out;
 207
 208         if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status))
 209                 lkb->lkb_flags |= DLM_IFL_ENDOFLIFE;
 210
 211         spin_lock(&proc->asts_spin);
 212
 213         rv = dlm_enqueue_lkb_callback(lkb, flags, mode, status, sbflags);
 214         switch (rv) {
 215         case DLM_ENQUEUE_CALLBACK_FAILURE:
 216                 spin_unlock(&proc->asts_spin);
 217                 WARN_ON_ONCE(1);
 218                 goto out;
 219         case DLM_ENQUEUE_CALLBACK_NEED_SCHED:
 220                 kref_get(&lkb->lkb_ref);
 221                 list_add_tail(&lkb->lkb_cb_list, &proc->asts);
 222                 wake_up_interruptible(&proc->wait);
 223                 break;
 224         case DLM_ENQUEUE_CALLBACK_SUCCESS:
 225                 break;
 226         default:
 227                 WARN_ON_ONCE(1);
 228                 break;
 229         }
 230         spin_unlock(&proc->asts_spin);
 231
 232         if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
 233                 /* N.B. spin_lock locks_spin, not asts_spin */
 234                 spin_lock(&proc->locks_spin);
 235                 if (!list_empty(&lkb->lkb_ownqueue)) {
 236                         list_del_init(&lkb->lkb_ownqueue);
 237                         dlm_put_lkb(lkb);
 238                 }
 239                 spin_unlock(&proc->locks_spin);
 240         }
 241  out:
 242         spin_unlock(&ls->ls_clear_proc_locks);
 243 }
 244
 245 static int device_user_lock(struct dlm_user_proc *proc,
 246                             struct dlm_lock_params *params)
 247 {
 248         struct dlm_ls *ls;
 249         struct dlm_user_args *ua;
 250         uint32_t lkid;
 251         int error = -ENOMEM;
 252
 253         ls = dlm_find_lockspace_local(proc->lockspace);
 254         if (!ls)
 255                 return -ENOENT;
 256
 257         if (!params->castaddr || !params->lksb) {
 258                 error = -EINVAL;
 259                 goto out;
 260         }
 261
 262 #ifdef CONFIG_DLM_DEPRECATED_API
 263         if (params->timeout)
 264                 pr_warn_once("========================================================\n"
 265                              "WARNING: the lkb timeout feature is being deprecated and\n"
 266                              "         will be removed in v6.2!\n"
 267                              "========================================================\n");
 268 #endif
 269
 270         ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
 271         if (!ua)
 272                 goto out;
 273         ua->proc = proc;
 274         ua->user_lksb = params->lksb;
 275         ua->castparam = params->castparam;
 276         ua->castaddr = params->castaddr;
 277         ua->bastparam = params->bastparam;
 278         ua->bastaddr = params->bastaddr;
 279         ua->xid = params->xid;
 280
 281         if (params->flags & DLM_LKF_CONVERT) {
 282 #ifdef CONFIG_DLM_DEPRECATED_API
 283                 error = dlm_user_convert(ls, ua,
 284                                          params->mode, params->flags,
 285                                          params->lkid, params->lvb,
 286                                          (unsigned long) params->timeout);
 287 #else
 288                 error = dlm_user_convert(ls, ua,
 289                                          params->mode, params->flags,
 290                                          params->lkid, params->lvb);
 291 #endif
 292         } else if (params->flags & DLM_LKF_ORPHAN) {
 293                 error = dlm_user_adopt_orphan(ls, ua,
 294                                          params->mode, params->flags,
 295                                          params->name, params->namelen,
 296                                          &lkid);
 297                 if (!error)
 298                         error = lkid;
 299         } else {
 300 #ifdef CONFIG_DLM_DEPRECATED_API
 301                 error = dlm_user_request(ls, ua,
 302                                          params->mode, params->flags,
 303                                          params->name, params->namelen,
 304                                          (unsigned long) params->timeout);
 305 #else
 306                 error = dlm_user_request(ls, ua,
 307                                          params->mode, params->flags,
 308                                          params->name, params->namelen);
 309 #endif
 310                 if (!error)
 311                         error = ua->lksb.sb_lkid;
 312         }
 313  out:
 314         dlm_put_lockspace(ls);
 315         return error;
 316 }
 317
 318 static int device_user_unlock(struct dlm_user_proc *proc,
 319                               struct dlm_lock_params *params)
 320 {
 321         struct dlm_ls *ls;
 322         struct dlm_user_args *ua;
 323         int error = -ENOMEM;
 324
 325         ls = dlm_find_lockspace_local(proc->lockspace);
 326         if (!ls)
 327                 return -ENOENT;
 328
 329         ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
 330         if (!ua)
 331                 goto out;
 332         ua->proc = proc;
 333         ua->user_lksb = params->lksb;
 334         ua->castparam = params->castparam;
 335         ua->castaddr = params->castaddr;
 336
 337         if (params->flags & DLM_LKF_CANCEL)
 338                 error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
 339         else
 340                 error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
 341                                         params->lvb);
 342  out:
 343         dlm_put_lockspace(ls);
 344         return error;
 345 }
 346
 347 static int device_user_deadlock(struct dlm_user_proc *proc,
 348                                 struct dlm_lock_params *params)
 349 {
 350         struct dlm_ls *ls;
 351         int error;
 352
 353         ls = dlm_find_lockspace_local(proc->lockspace);
 354         if (!ls)
 355                 return -ENOENT;
 356
 357         error = dlm_user_deadlock(ls, params->flags, params->lkid);
 358
 359         dlm_put_lockspace(ls);
 360         return error;
 361 }
 362
 363 static int dlm_device_register(struct dlm_ls *ls, char *name)
 364 {
 365         int error, len;
 366
 367         /* The device is already registered.  This happens when the
 368            lockspace is created multiple times from userspace. */
 369         if (ls->ls_device.name)
 370                 return 0;
 371
 372         error = -ENOMEM;
 373         len = strlen(name) + strlen(name_prefix) + 2;
 374         ls->ls_device.name = kzalloc(len, GFP_NOFS);
 375         if (!ls->ls_device.name)
 376                 goto fail;
 377
 378         snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
 379                  name);
 380         ls->ls_device.fops = &device_fops;
 381         ls->ls_device.minor = MISC_DYNAMIC_MINOR;
 382
 383         error = misc_register(&ls->ls_device);
 384         if (error) {
 385                 kfree(ls->ls_device.name);
 386                 /* this has to be set to NULL
 387                  * to avoid a double-free in dlm_device_deregister
 388                  */
 389                 ls->ls_device.name = NULL;
 390         }
 391 fail:
 392         return error;
 393 }
 394
 395 int dlm_device_deregister(struct dlm_ls *ls)
 396 {
 397         /* The device is not registered.  This happens when the lockspace
 398            was never used from userspace, or when device_create_lockspace()
 399            calls dlm_release_lockspace() after the register fails. */
 400         if (!ls->ls_device.name)
 401                 return 0;
 402
 403         misc_deregister(&ls->ls_device);
 404         kfree(ls->ls_device.name);
 405         return 0;
 406 }
 407
 408 static int device_user_purge(struct dlm_user_proc *proc,
 409                              struct dlm_purge_params *params)
 410 {
 411         struct dlm_ls *ls;
 412         int error;
 413
 414         ls = dlm_find_lockspace_local(proc->lockspace);
 415         if (!ls)
 416                 return -ENOENT;
 417
 418         error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
 419
 420         dlm_put_lockspace(ls);
 421         return error;
 422 }
 423
 424 static int device_create_lockspace(struct dlm_lspace_params *params)
 425 {
 426         dlm_lockspace_t *lockspace;
 427         struct dlm_ls *ls;
 428         int error;
 429
 430         if (!capable(CAP_SYS_ADMIN))
 431                 return -EPERM;
 432
 433         error = dlm_new_user_lockspace(params->name, dlm_config.ci_cluster_name,
 434                                        params->flags, DLM_USER_LVB_LEN, NULL,
 435                                        NULL, NULL, &lockspace);
 436         if (error)
 437                 return error;
 438
 439         ls = dlm_find_lockspace_local(lockspace);
 440         if (!ls)
 441                 return -ENOENT;
 442
 443         error = dlm_device_register(ls, params->name);
 444         dlm_put_lockspace(ls);
 445
 446         if (error)
 447                 dlm_release_lockspace(lockspace, 0);
 448         else
 449                 error = ls->ls_device.minor;
 450
 451         return error;
 452 }
 453
 454 static int device_remove_lockspace(struct dlm_lspace_params *params)
 455 {
 456         dlm_lockspace_t *lockspace;
 457         struct dlm_ls *ls;
 458         int error, force = 0;
 459
 460         if (!capable(CAP_SYS_ADMIN))
 461                 return -EPERM;
 462
 463         ls = dlm_find_lockspace_device(params->minor);
 464         if (!ls)
 465                 return -ENOENT;
 466
 467         if (params->flags & DLM_USER_LSFLG_FORCEFREE)
 468                 force = 2;
 469
 470         lockspace = ls->ls_local_handle;
 471         dlm_put_lockspace(ls);
 472
 473         /* The final dlm_release_lockspace waits for references to go to
 474            zero, so all processes will need to close their device for the
 475            ls before the release will proceed.  release also calls the
 476            device_deregister above.  Converting a positive return value
 477            from release to zero means that userspace won't know when its
 478            release was the final one, but it shouldn't need to know. */
 479
 480         error = dlm_release_lockspace(lockspace, force);
 481         if (error > 0)
 482                 error = 0;
 483         return error;
 484 }
 485
 486 /* Check the user's version matches ours */
 487 static int check_version(struct dlm_write_request *req)
 488 {
 489         if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
 490             (req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
 491              req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
 492
 493                 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
 494                        "user (%d.%d.%d) kernel (%d.%d.%d)\n",
 495                        current->comm,
 496                        task_pid_nr(current),
 497                        req->version[0],
 498                        req->version[1],
 499                        req->version[2],
 500                        DLM_DEVICE_VERSION_MAJOR,
 501                        DLM_DEVICE_VERSION_MINOR,
 502                        DLM_DEVICE_VERSION_PATCH);
 503                 return -EINVAL;
 504         }
 505         return 0;
 506 }
 507
 508 /*
 509  * device_write
 510  *
 511  *   device_user_lock
 512  *     dlm_user_request -> request_lock
 513  *     dlm_user_convert -> convert_lock
 514  *
 515  *   device_user_unlock
 516  *     dlm_user_unlock -> unlock_lock
 517  *     dlm_user_cancel -> cancel_lock
 518  *
 519  *   device_create_lockspace
 520  *     dlm_new_lockspace
 521  *
 522  *   device_remove_lockspace
 523  *     dlm_release_lockspace
 524  */
 525
 526 /* a write to a lockspace device is a lock or unlock request, a write
 527    to the control device is to create/remove a lockspace */
 528
 529 static ssize_t device_write(struct file *file, const char __user *buf,
 530                             size_t count, loff_t *ppos)
 531 {
 532         struct dlm_user_proc *proc = file->private_data;
 533         struct dlm_write_request *kbuf;
 534         int error;
 535
 536 #ifdef CONFIG_COMPAT
 537         if (count < sizeof(struct dlm_write_request32))
 538 #else
 539         if (count < sizeof(struct dlm_write_request))
 540 #endif
 541                 return -EINVAL;
 542
 543         /*
 544          * can't compare against COMPAT/dlm_write_request32 because
 545          * we don't yet know if is64bit is zero
 546          */
 547         if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN)
 548                 return -EINVAL;
 549
 550         kbuf = memdup_user_nul(buf, count);
 551         if (IS_ERR(kbuf))
 552                 return PTR_ERR(kbuf);
 553
 554         if (check_version(kbuf)) {
 555                 error = -EBADE;
 556                 goto out_free;
 557         }
 558
 559 #ifdef CONFIG_COMPAT
 560         if (!kbuf->is64bit) {
 561                 struct dlm_write_request32 *k32buf;
 562                 int namelen = 0;
 563
 564                 if (count > sizeof(struct dlm_write_request32))
 565                         namelen = count - sizeof(struct dlm_write_request32);
 566
 567                 k32buf = (struct dlm_write_request32 *)kbuf;
 568
 569                 /* add 1 after namelen so that the name string is terminated */
 570                 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
 571                                GFP_NOFS);
 572                 if (!kbuf) {
 573                         kfree(k32buf);
 574                         return -ENOMEM;
 575                 }
 576
 577                 if (proc)
 578                         set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
 579
 580                 compat_input(kbuf, k32buf, namelen);
 581                 kfree(k32buf);
 582         }
 583 #endif
 584
 585         /* do we really need this? can a write happen after a close? */
 586         if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
 587             (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
 588                 error = -EINVAL;
 589                 goto out_free;
 590         }
 591
 592         error = -EINVAL;
 593
 594         switch (kbuf->cmd)
 595         {
 596         case DLM_USER_LOCK:
 597                 if (!proc) {
 598                         log_print("no locking on control device");
 599                         goto out_free;
 600                 }
 601                 error = device_user_lock(proc, &kbuf->i.lock);
 602                 break;
 603
 604         case DLM_USER_UNLOCK:
 605                 if (!proc) {
 606                         log_print("no locking on control device");
 607                         goto out_free;
 608                 }
 609                 error = device_user_unlock(proc, &kbuf->i.lock);
 610                 break;
 611
 612         case DLM_USER_DEADLOCK:
 613                 if (!proc) {
 614                         log_print("no locking on control device");
 615                         goto out_free;
 616                 }
 617                 error = device_user_deadlock(proc, &kbuf->i.lock);
 618                 break;
 619
 620         case DLM_USER_CREATE_LOCKSPACE:
 621                 if (proc) {
 622                         log_print("create/remove only on control device");
 623                         goto out_free;
 624                 }
 625                 error = device_create_lockspace(&kbuf->i.lspace);
 626                 break;
 627
 628         case DLM_USER_REMOVE_LOCKSPACE:
 629                 if (proc) {
 630                         log_print("create/remove only on control device");
 631                         goto out_free;
 632                 }
 633                 error = device_remove_lockspace(&kbuf->i.lspace);
 634                 break;
 635
 636         case DLM_USER_PURGE:
 637                 if (!proc) {
 638                         log_print("no locking on control device");
 639                         goto out_free;
 640                 }
 641                 error = device_user_purge(proc, &kbuf->i.purge);
 642                 break;
 643
 644         default:
 645                 log_print("Unknown command passed to DLM device : %d\n",
 646                           kbuf->cmd);
 647         }
 648
 649  out_free:
 650         kfree(kbuf);
 651         return error;
 652 }
 653
 654 /* Every process that opens the lockspace device has its own "proc" structure
 655    hanging off the open file that's used to keep track of locks owned by the
 656    process and asts that need to be delivered to the process. */
 657
 658 static int device_open(struct inode *inode, struct file *file)
 659 {
 660         struct dlm_user_proc *proc;
 661         struct dlm_ls *ls;
 662
 663         ls = dlm_find_lockspace_device(iminor(inode));
 664         if (!ls)
 665                 return -ENOENT;
 666
 667         proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS);
 668         if (!proc) {
 669                 dlm_put_lockspace(ls);
 670                 return -ENOMEM;
 671         }
 672
 673         proc->lockspace = ls->ls_local_handle;
 674         INIT_LIST_HEAD(&proc->asts);
 675         INIT_LIST_HEAD(&proc->locks);
 676         INIT_LIST_HEAD(&proc->unlocking);
 677         spin_lock_init(&proc->asts_spin);
 678         spin_lock_init(&proc->locks_spin);
 679         init_waitqueue_head(&proc->wait);
 680         file->private_data = proc;
 681
 682         return 0;
 683 }
 684
 685 static int device_close(struct inode *inode, struct file *file)
 686 {
 687         struct dlm_user_proc *proc = file->private_data;
 688         struct dlm_ls *ls;
 689
 690         ls = dlm_find_lockspace_local(proc->lockspace);
 691         if (!ls)
 692                 return -ENOENT;
 693
 694         set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags);
 695
 696         dlm_clear_proc_locks(ls, proc);
 697
 698         /* at this point no more lkb's should exist for this lockspace,
 699            so there's no chance of dlm_user_add_ast() being called and
 700            looking for lkb->ua->proc */
 701
 702         kfree(proc);
 703         file->private_data = NULL;
 704
 705         dlm_put_lockspace(ls);
 706         dlm_put_lockspace(ls);  /* for the find in device_open() */
 707
 708         /* FIXME: AUTOFREE: if this ls is no longer used do
 709            device_remove_lockspace() */
 710
 711         return 0;
 712 }
 713
 714 static int copy_result_to_user(struct dlm_user_args *ua, int compat,
 715                                uint32_t flags, int mode, int copy_lvb,
 716                                char __user *buf, size_t count)
 717 {
 718 #ifdef CONFIG_COMPAT
 719         struct dlm_lock_result32 result32;
 720 #endif
 721         struct dlm_lock_result result;
 722         void *resultptr;
 723         int error=0;
 724         int len;
 725         int struct_len;
 726
 727         memset(&result, 0, sizeof(struct dlm_lock_result));
 728         result.version[0] = DLM_DEVICE_VERSION_MAJOR;
 729         result.version[1] = DLM_DEVICE_VERSION_MINOR;
 730         result.version[2] = DLM_DEVICE_VERSION_PATCH;
 731         memcpy(&result.lksb, &ua->lksb, offsetof(struct dlm_lksb, sb_lvbptr));
 732         result.user_lksb = ua->user_lksb;
 733
 734         /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated
 735            in a conversion unless the conversion is successful.  See code
 736            in dlm_user_convert() for updating ua from ua_tmp.  OpenVMS, though,
 737            notes that a new blocking AST address and parameter are set even if
 738            the conversion fails, so maybe we should just do that. */
 739
 740         if (flags & DLM_CB_BAST) {
 741                 result.user_astaddr = ua->bastaddr;
 742                 result.user_astparam = ua->bastparam;
 743                 result.bast_mode = mode;
 744         } else {
 745                 result.user_astaddr = ua->castaddr;
 746                 result.user_astparam = ua->castparam;
 747         }
 748
 749 #ifdef CONFIG_COMPAT
 750         if (compat)
 751                 len = sizeof(struct dlm_lock_result32);
 752         else
 753 #endif
 754                 len = sizeof(struct dlm_lock_result);
 755         struct_len = len;
 756
 757         /* copy lvb to userspace if there is one, it's been updated, and
 758            the user buffer has space for it */
 759
 760         if (copy_lvb && ua->lksb.sb_lvbptr && count >= len + DLM_USER_LVB_LEN) {
 761                 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr,
 762                                  DLM_USER_LVB_LEN)) {
 763                         error = -EFAULT;
 764                         goto out;
 765                 }
 766
 767                 result.lvb_offset = len;
 768                 len += DLM_USER_LVB_LEN;
 769         }
 770
 771         result.length = len;
 772         resultptr = &result;
 773 #ifdef CONFIG_COMPAT
 774         if (compat) {
 775                 compat_output(&result, &result32);
 776                 resultptr = &result32;
 777         }
 778 #endif
 779
 780         if (copy_to_user(buf, resultptr, struct_len))
 781                 error = -EFAULT;
 782         else
 783                 error = len;
 784  out:
 785         return error;
 786 }
 787
 788 static int copy_version_to_user(char __user *buf, size_t count)
 789 {
 790         struct dlm_device_version ver;
 791
 792         memset(&ver, 0, sizeof(struct dlm_device_version));
 793         ver.version[0] = DLM_DEVICE_VERSION_MAJOR;
 794         ver.version[1] = DLM_DEVICE_VERSION_MINOR;
 795         ver.version[2] = DLM_DEVICE_VERSION_PATCH;
 796
 797         if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version)))
 798                 return -EFAULT;
 799         return sizeof(struct dlm_device_version);
 800 }
 801
 802 /* a read returns a single ast described in a struct dlm_lock_result */
 803
 804 static ssize_t device_read(struct file *file, char __user *buf, size_t count,
 805                            loff_t *ppos)
 806 {
 807         struct dlm_user_proc *proc = file->private_data;
 808         struct dlm_lkb *lkb;
 809         DECLARE_WAITQUEUE(wait, current);
 810         struct dlm_callback *cb;
 811         int rv, copy_lvb = 0;
 812         int old_mode, new_mode;
 813
 814         if (count == sizeof(struct dlm_device_version)) {
 815                 rv = copy_version_to_user(buf, count);
 816                 return rv;
 817         }
 818
 819         if (!proc) {
 820                 log_print("non-version read from control device %zu", count);
 821                 return -EINVAL;
 822         }
 823
 824 #ifdef CONFIG_COMPAT
 825         if (count < sizeof(struct dlm_lock_result32))
 826 #else
 827         if (count < sizeof(struct dlm_lock_result))
 828 #endif
 829                 return -EINVAL;
 830
 831  try_another:
 832
 833         /* do we really need this? can a read happen after a close? */
 834         if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
 835                 return -EINVAL;
 836
 837         spin_lock(&proc->asts_spin);
 838         if (list_empty(&proc->asts)) {
 839                 if (file->f_flags & O_NONBLOCK) {
 840                         spin_unlock(&proc->asts_spin);
 841                         return -EAGAIN;
 842                 }
 843
 844                 add_wait_queue(&proc->wait, &wait);
 845
 846         repeat:
 847                 set_current_state(TASK_INTERRUPTIBLE);
 848                 if (list_empty(&proc->asts) && !signal_pending(current)) {
 849                         spin_unlock(&proc->asts_spin);
 850                         schedule();
 851                         spin_lock(&proc->asts_spin);
 852                         goto repeat;
 853                 }
 854                 set_current_state(TASK_RUNNING);
 855                 remove_wait_queue(&proc->wait, &wait);
 856
 857                 if (signal_pending(current)) {
 858                         spin_unlock(&proc->asts_spin);
 859                         return -ERESTARTSYS;
 860                 }
 861         }
 862
 863         /* if we empty lkb_callbacks, we don't want to unlock the spinlock
 864            without removing lkb_cb_list; so empty lkb_cb_list is always
 865            consistent with empty lkb_callbacks */
 866
 867         lkb = list_first_entry(&proc->asts, struct dlm_lkb, lkb_cb_list);
 868
 869         /* rem_lkb_callback sets a new lkb_last_cast */
 870         old_mode = lkb->lkb_last_cast->mode;
 871
 872         rv = dlm_dequeue_lkb_callback(lkb, &cb);
 873         switch (rv) {
 874         case DLM_DEQUEUE_CALLBACK_EMPTY:
 875                 /* this shouldn't happen; lkb should have been removed from
 876                  * list when last item was dequeued
 877                  */
 878                 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id);
 879                 list_del_init(&lkb->lkb_cb_list);
 880                 spin_unlock(&proc->asts_spin);
 881                 /* removes ref for proc->asts, may cause lkb to be freed */
 882                 dlm_put_lkb(lkb);
 883                 WARN_ON_ONCE(1);
 884                 goto try_another;
 885         case DLM_DEQUEUE_CALLBACK_LAST:
 886                 list_del_init(&lkb->lkb_cb_list);
 887                 lkb->lkb_flags &= ~DLM_IFL_CB_PENDING;
 888                 break;
 889         case DLM_DEQUEUE_CALLBACK_SUCCESS:
 890                 break;
 891         default:
 892                 WARN_ON_ONCE(1);
 893                 break;
 894         }
 895         spin_unlock(&proc->asts_spin);
 896
 897         if (cb->flags & DLM_CB_BAST) {
 898                 trace_dlm_bast(lkb->lkb_resource->res_ls, lkb, cb->mode);
 899         } else if (cb->flags & DLM_CB_CAST) {
 900                 new_mode = cb->mode;
 901
 902                 if (!cb->sb_status && lkb->lkb_lksb->sb_lvbptr &&
 903                     dlm_lvb_operations[old_mode + 1][new_mode + 1])
 904                         copy_lvb = 1;
 905
 906                 lkb->lkb_lksb->sb_status = cb->sb_status;
 907                 lkb->lkb_lksb->sb_flags = cb->sb_flags;
 908                 trace_dlm_ast(lkb->lkb_resource->res_ls, lkb);
 909         }
 910
 911         rv = copy_result_to_user(lkb->lkb_ua,
 912                                  test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
 913                                  cb->flags, cb->mode, copy_lvb, buf, count);
 914
 915         kref_put(&cb->ref, dlm_release_callback);
 916
 917         /* removes ref for proc->asts, may cause lkb to be freed */
 918         if (rv == DLM_DEQUEUE_CALLBACK_LAST)
 919                 dlm_put_lkb(lkb);
 920
 921         return rv;
 922 }
 923
 924 static __poll_t device_poll(struct file *file, poll_table *wait)
 925 {
 926         struct dlm_user_proc *proc = file->private_data;
 927
 928         poll_wait(file, &proc->wait, wait);
 929
 930         spin_lock(&proc->asts_spin);
 931         if (!list_empty(&proc->asts)) {
 932                 spin_unlock(&proc->asts_spin);
 933                 return EPOLLIN | EPOLLRDNORM;
 934         }
 935         spin_unlock(&proc->asts_spin);
 936         return 0;
 937 }
 938
 939 int dlm_user_daemon_available(void)
 940 {
 941         /* dlm_controld hasn't started (or, has started, but not
 942            properly populated configfs) */
 943
 944         if (!dlm_our_nodeid())
 945                 return 0;
 946
 947         /* This is to deal with versions of dlm_controld that don't
 948            know about the monitor device.  We assume that if the
 949            dlm_controld was started (above), but the monitor device
 950            was never opened, that it's an old version.  dlm_controld
 951            should open the monitor device before populating configfs. */
 952
 953         if (dlm_monitor_unused)
 954                 return 1;
 955
 956         return atomic_read(&dlm_monitor_opened) ? 1 : 0;
 957 }
 958
 959 static int ctl_device_open(struct inode *inode, struct file *file)
 960 {
 961         file->private_data = NULL;
 962         return 0;
 963 }
 964
 965 static int ctl_device_close(struct inode *inode, struct file *file)
 966 {
 967         return 0;
 968 }
 969
 970 static int monitor_device_open(struct inode *inode, struct file *file)
 971 {
 972         atomic_inc(&dlm_monitor_opened);
 973         dlm_monitor_unused = 0;
 974         return 0;
 975 }
 976
 977 static int monitor_device_close(struct inode *inode, struct file *file)
 978 {
 979         if (atomic_dec_and_test(&dlm_monitor_opened))
 980                 dlm_stop_lockspaces();
 981         return 0;
 982 }
 983
 984 static const struct file_operations device_fops = {
 985         .open    = device_open,
 986         .release = device_close,
 987         .read    = device_read,
 988         .write   = device_write,
 989         .poll    = device_poll,
 990         .owner   = THIS_MODULE,
 991         .llseek  = noop_llseek,
 992 };
 993
 994 static const struct file_operations ctl_device_fops = {
 995         .open    = ctl_device_open,
 996         .release = ctl_device_close,
 997         .read    = device_read,
 998         .write   = device_write,
 999         .owner   = THIS_MODULE,
1000         .llseek  = noop_llseek,
1001 };
1002
1003 static struct miscdevice ctl_device = {
1004         .name  = "dlm-control",
1005         .fops  = &ctl_device_fops,
1006         .minor = MISC_DYNAMIC_MINOR,
1007 };
1008
1009 static const struct file_operations monitor_device_fops = {
1010         .open    = monitor_device_open,
1011         .release = monitor_device_close,
1012         .owner   = THIS_MODULE,
1013         .llseek  = noop_llseek,
1014 };
1015
1016 static struct miscdevice monitor_device = {
1017         .name  = "dlm-monitor",
1018         .fops  = &monitor_device_fops,
1019         .minor = MISC_DYNAMIC_MINOR,
1020 };
1021
1022 int __init dlm_user_init(void)
1023 {
1024         int error;
1025
1026         atomic_set(&dlm_monitor_opened, 0);
1027
1028         error = misc_register(&ctl_device);
1029         if (error) {
1030                 log_print("misc_register failed for control device");
1031                 goto out;
1032         }
1033
1034         error = misc_register(&monitor_device);
1035         if (error) {
1036                 log_print("misc_register failed for monitor device");
1037                 misc_deregister(&ctl_device);
1038         }
1039  out:
1040         return error;
1041 }
1042
1043 void dlm_user_exit(void)
1044 {
1045         misc_deregister(&ctl_device);
1046         misc_deregister(&monitor_device);
1047 }
1048