source3/modules/onefs_cbrl.c

   1 /*
   2  * Unix SMB/CIFS implementation.
   3  * Support for OneFS system interfaces.
   4  *
   5  * Copyright (C) Zack Kirsch, 2009
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "onefs.h"
  22
  23 #include <ifs/ifs_syscalls.h>
  24 #include <sys/isi_cifs_brl.h>
  25 #include <isi_ecs/isi_ecs_cbrl.h>
  26
  27 #undef DBGC_CLASS
  28 #define DBGC_CLASS DBGC_LOCKING
  29
  30 extern struct blocking_lock_record *blocking_lock_queue;
  31
  32 static uint64_t onefs_get_new_id(void) {
  33         static uint64_t id = 0;
  34
  35         id++;
  36
  37         return id;
  38 }
  39
  40 enum onefs_cbrl_lock_state {ONEFS_CBRL_NONE, ONEFS_CBRL_ASYNC, ONEFS_CBRL_DONE,
  41         ONEFS_CBRL_ERROR};
  42
  43 struct onefs_cbrl_blr_state {
  44         uint64_t id;
  45         enum onefs_cbrl_lock_state state;
  46 };
  47
  48 static char *onefs_cbrl_blr_state_str(const struct blocking_lock_record *blr)
  49 {
  50         static fstring result;
  51         struct onefs_cbrl_blr_state *bs;
  52
  53         SMB_ASSERT(blr);
  54
  55         bs = (struct onefs_cbrl_blr_state *)blr->blr_private;
  56
  57         if (bs == NULL) {
  58                 fstrcpy(result, "NULL CBRL BLR state - Posix lock?");
  59                 return result;
  60         }
  61
  62         switch (bs->state) {
  63         case ONEFS_CBRL_NONE:
  64                 fstr_sprintf(result, "CBRL BLR id=%llu: state=NONE", bs->id);
  65                 break;
  66         case ONEFS_CBRL_ASYNC:
  67                 fstr_sprintf(result, "CBRL BLR id=%llu: state=ASYNC", bs->id);
  68                 break;
  69         case ONEFS_CBRL_DONE:
  70                 fstr_sprintf(result, "CBRL BLR id=%llu: state=DONE", bs->id);
  71                 break;
  72         case ONEFS_CBRL_ERROR:
  73                 fstr_sprintf(result, "CBRL BLR id=%llu: state=ERROR", bs->id);
  74                 break;
  75         default:
  76                 fstr_sprintf(result, "CBRL BLR id=%llu: unknown state %d",
  77                     bs->id, bs->state);
  78                 break;
  79         }
  80
  81         return result;
  82 }
  83
  84 static void onefs_cbrl_enumerate_blq(const char *fn)
  85 {
  86         struct blocking_lock_record *blr;
  87
  88         if (DEBUGLVL(10))
  89                 return;
  90
  91         DEBUG(10, ("CBRL BLR records (%s):\n", fn));
  92
  93         for (blr = blocking_lock_queue; blr; blr = blr->next)
  94                 DEBUGADD(10, ("%s\n", onefs_cbrl_blr_state_str(blr)));
  95 }
  96
  97 static struct blocking_lock_record *onefs_cbrl_find_blr(uint64_t id)
  98 {
  99         struct blocking_lock_record *blr;
 100         struct onefs_cbrl_blr_state *bs;
 101
 102         onefs_cbrl_enumerate_blq("onefs_cbrl_find_blr");
 103
 104         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 105                 bs = (struct onefs_cbrl_blr_state *)blr->blr_private;
 106
 107                 /* We don't control all of the BLRs on the BLQ. */
 108                 if (bs == NULL)
 109                         continue;
 110
 111                 if (bs->id == id) {
 112                         DEBUG(10, ("found %s\n",
 113                             onefs_cbrl_blr_state_str(blr)));
 114                         break;
 115                 }
 116         }
 117
 118         if (blr == NULL) {
 119                 DEBUG(5, ("Could not find CBRL BLR for id %llu\n", id));
 120                 return NULL;
 121         }
 122
 123         return blr;
 124 }
 125
 126 static void onefs_cbrl_async_success(uint64_t id)
 127 {
 128         struct blocking_lock_record *blr;
 129         struct onefs_cbrl_blr_state *bs;
 130         uint16 num_locks;
 131
 132         DEBUG(10, ("CBRL async success!\n"));
 133
 134         /* Find BLR with id. Its okay not to find one (race with cancel) */
 135         blr = onefs_cbrl_find_blr(id);
 136         if (blr == NULL)
 137                 return;
 138
 139         bs = (struct onefs_cbrl_blr_state *)blr->blr_private;
 140         SMB_ASSERT(bs);
 141         SMB_ASSERT(bs->state == ONEFS_CBRL_ASYNC);
 142
 143         blr->lock_num++;
 144
 145         num_locks = SVAL(blr->req->vwv+7, 0);
 146
 147         if (blr->lock_num == num_locks)
 148                 bs->state = ONEFS_CBRL_DONE;
 149         else
 150                 bs->state = ONEFS_CBRL_NONE;
 151
 152         /* Process the queue, to try the next lock or finish up. */
 153         process_blocking_lock_queue();
 154 }
 155
 156 static void onefs_cbrl_async_failure(uint64_t id)
 157 {
 158         struct blocking_lock_record *blr;
 159         struct onefs_cbrl_blr_state *bs;
 160
 161         DEBUG(10, ("CBRL async failure!\n"));
 162
 163         /* Find BLR with id. Its okay not to find one (race with cancel) */
 164         blr = onefs_cbrl_find_blr(id);
 165         if (blr == NULL)
 166                 return;
 167
 168         bs = (struct onefs_cbrl_blr_state *)blr->blr_private;
 169         SMB_ASSERT(bs);
 170
 171         SMB_ASSERT(bs->state == ONEFS_CBRL_ASYNC);
 172         bs->state = ONEFS_CBRL_ERROR;
 173
 174         /* Process the queue. It will end up trying to retake the same lock,
 175          * see the error in onefs_cbrl_lock_windows() and fail. */
 176         process_blocking_lock_queue();
 177 }
 178
 179 static struct cbrl_event_ops cbrl_ops =
 180     {.cbrl_async_success = onefs_cbrl_async_success,
 181      .cbrl_async_failure = onefs_cbrl_async_failure};
 182
 183 static void onefs_cbrl_events_handler(struct event_context *ev,
 184                                         struct fd_event *fde,
 185                                         uint16_t flags,
 186                                         void *private_data)
 187 {
 188         DEBUG(10, ("onefs_cbrl_events_handler\n"));
 189
 190         if (cbrl_event_dispatcher(&cbrl_ops)) {
 191                 DEBUG(0, ("cbrl_event_dispatcher failed: %s\n",
 192                         strerror(errno)));
 193         }
 194 }
 195
 196 static void onefs_init_cbrl(void)
 197 {
 198         static bool init_done = false;
 199         static int cbrl_event_fd;
 200         static struct fd_event *cbrl_fde;
 201
 202         if (init_done)
 203                 return;
 204
 205         DEBUG(10, ("onefs_init_cbrl\n"));
 206
 207         /* Register the event channel for CBRL. */
 208         cbrl_event_fd = cbrl_event_register();
 209         if (cbrl_event_fd == -1) {
 210                 DEBUG(0, ("cbrl_event_register failed: %s\n",
 211                         strerror(errno)));
 212                 return;
 213         }
 214
 215         DEBUG(10, ("cbrl_event_fd = %d\n", cbrl_event_fd));
 216
 217         /* Register the oplock event_fd with samba's event system */
 218         cbrl_fde = event_add_fd(smbd_event_context(),
 219                                      NULL,
 220                                      cbrl_event_fd,
 221                                      EVENT_FD_READ,
 222                                      onefs_cbrl_events_handler,
 223                                      NULL);
 224
 225         init_done = true;
 226         return;
 227 }
 228
 229 /**
 230  * Blocking PID. As far as I can tell, the blocking_pid is only used to tell
 231  * whether a posix lock or a CIFS lock blocked us. If it was a posix lock,
 232  * Samba polls every 10 seconds, which we don't want. -zkirsch
 233  */
 234 #define ONEFS_BLOCKING_PID 0xABCDABCD
 235
 236 /**
 237  * @param[in]     br_lck        Contains the fsp.
 238  * @param[in]     plock         Lock request.
 239  * @param[in]     blocking_lock Only used for figuring out the error.
 240  * @param[in,out] blr           The BLR for the already-deferred operation.
 241  */
 242 NTSTATUS onefs_brl_lock_windows(vfs_handle_struct *handle,
 243                                 struct byte_range_lock *br_lck,
 244                                 struct lock_struct *plock,
 245                                 bool blocking_lock,
 246                                 struct blocking_lock_record *blr)
 247 {
 248         int fd = br_lck->fsp->fh->fd;
 249         uint64_t id = 0;
 250         bool exclusive = false;
 251         bool async = false;
 252         bool pending = false;
 253         bool pending_async = false;
 254         int error;
 255         struct onefs_cbrl_blr_state *bs;
 256         NTSTATUS status;
 257
 258         SMB_ASSERT(plock->lock_flav == WINDOWS_LOCK);
 259         SMB_ASSERT(plock->lock_type != UNLOCK_LOCK);
 260
 261         onefs_cbrl_enumerate_blq("onefs_brl_lock_windows");
 262
 263         /* Will only initialize the first time its called. */
 264         onefs_init_cbrl();
 265
 266         switch (plock->lock_type) {
 267                 case WRITE_LOCK:
 268                         exclusive = true;
 269                         break;
 270                 case READ_LOCK:
 271                         break;
 272                 case PENDING_WRITE_LOCK:
 273                         /* Called when a blocking lock request is added - do an
 274                          * async lock. */
 275                         pending = true;
 276                         async = true;
 277                         exclusive = true;
 278                         break;
 279                 case PENDING_READ_LOCK:
 280                         /* Called when a blocking lock request is added - do an
 281                          * async lock. */
 282                         pending = true;
 283                         async = true;
 284                         break;
 285                 default:
 286                         /* UNLOCK_LOCK: should only be used for a POSIX_LOCK */
 287                         smb_panic("Invalid plock->lock_type passed in to "
 288                             "onefs_brl_lock_windows");
 289         }
 290
 291         /* Figure out if we're actually doing the lock or a no-op. We need to
 292          * do a no-op when process_blocking_lock_queue calls back into us.
 293          *
 294          * We know process_* is calling into us if a blr is passed in and
 295          * pending is false. */
 296         if (!pending && blr) {
 297                 /* Check the BLR state. */
 298                 bs = (struct onefs_cbrl_blr_state *)blr->blr_private;
 299                 SMB_ASSERT(bs);
 300
 301                 /* ASYNC still in progress: The process_* calls will keep
 302                  * calling even if we haven't gotten the lock. Keep erroring
 303                  * without calling ifs_cbrl, or getting/setting an id. */
 304                 if (bs->state == ONEFS_CBRL_ASYNC)
 305                         goto failure;
 306                 else if (bs->state == ONEFS_CBRL_ERROR)
 307                         return NT_STATUS_NO_MEMORY;
 308
 309                 SMB_ASSERT(bs->state == ONEFS_CBRL_NONE);
 310                 async = true;
 311         }
 312
 313         if (async) {
 314                 SMB_ASSERT(blocking_lock);
 315                 SMB_ASSERT(blr);
 316                 id = onefs_get_new_id();
 317         }
 318
 319         DEBUG(10, ("Calling ifs_cbrl(LOCK)..."));
 320         error = ifs_cbrl(fd, CBRL_OP_LOCK, exclusive, plock->start,
 321             plock->size, async, id, plock->context.smbpid, plock->context.tid);
 322         if (!error) {
 323                 goto success;
 324         } else if (errno == EWOULDBLOCK) {
 325                 SMB_ASSERT(!async);
 326         } else if (errno == EINPROGRESS) {
 327                 SMB_ASSERT(async);
 328
 329                 if (pending) {
 330                         /* Talloc a new BLR private state. */
 331                         blr->blr_private = talloc(blr, struct onefs_cbrl_blr_state);
 332                         pending_async = true;
 333                 }
 334
 335                 /* Store the new id in the BLR private state. */
 336                 bs = (struct onefs_cbrl_blr_state *)blr->blr_private;
 337                 bs->id = id;
 338                 bs->state = ONEFS_CBRL_ASYNC;
 339         } else {
 340                 DEBUG(0, ("onefs_brl_lock_windows failure: error=%d (%s).\n",
 341                         errno, strerror(errno)));
 342         }
 343
 344 failure:
 345         /* Failure - error or async. */
 346         plock->context.smbpid = (uint32) ONEFS_BLOCKING_PID;
 347
 348         if (pending_async)
 349                 status = NT_STATUS_OK;
 350         else
 351                 status = brl_lock_failed(br_lck->fsp, plock, blocking_lock);
 352
 353         DEBUG(10, ("returning %s.\n", nt_errstr(status)));
 354         return status;
 355
 356 success:
 357         /* Success. */
 358         onefs_cbrl_enumerate_blq("onefs_brl_unlock_windows");
 359         DEBUG(10, ("returning NT_STATUS_OK.\n"));
 360         return NT_STATUS_OK;
 361 }
 362
 363 #define CBRL_NOTYPE true
 364
 365 bool onefs_brl_unlock_windows(vfs_handle_struct *handle,
 366                               struct messaging_context *msg_ctx,
 367                               struct byte_range_lock *br_lck,
 368                               const struct lock_struct *plock)
 369 {
 370         int error;
 371         int fd = br_lck->fsp->fh->fd;
 372
 373         SMB_ASSERT(plock->lock_flav == WINDOWS_LOCK);
 374         SMB_ASSERT(plock->lock_type == UNLOCK_LOCK);
 375
 376         DEBUG(10, ("Calling ifs_cbrl(UNLOCK)..."));
 377         error = ifs_cbrl(fd, CBRL_OP_UNLOCK, CBRL_NOTYPE,
 378             plock->start, plock->size, CBRL_NOTYPE, 0, plock->context.smbpid,
 379             plock->context.tid);
 380         if (error) {
 381                 DEBUG(10, ("returning false.\n"));
 382                 return false;
 383         }
 384
 385         DEBUG(10, ("returning true.\n"));
 386         return true;
 387
 388         /* Problem with storing things in TDB: I won't know what BRL to unlock in the TDB.
 389          *  - I could fake it?
 390          *  - I could send Samba a message with which lock is being unlocked?
 391          *  - I could *easily* make the "id" something you always pass in to
 392          *  lock, unlock or cancel -- it identifies a lock. Makes sense!
 393          */
 394 }
 395
 396 /* Default implementation only calls this on PENDING locks. */
 397 bool onefs_brl_cancel_windows(vfs_handle_struct *handle,
 398                               struct byte_range_lock *br_lck,
 399                               struct lock_struct *plock,
 400                               struct blocking_lock_record *blr)
 401 {
 402         int error;
 403         int fd = br_lck->fsp->fh->fd;
 404         struct onefs_cbrl_blr_state *bs;
 405
 406         SMB_ASSERT(plock);
 407         SMB_ASSERT(plock->lock_flav == WINDOWS_LOCK);
 408         SMB_ASSERT(blr);
 409
 410         onefs_cbrl_enumerate_blq("onefs_brl_cancel_windows");
 411
 412         bs = ((struct onefs_cbrl_blr_state *)blr->blr_private);
 413         SMB_ASSERT(bs);
 414
 415         if (bs->state == ONEFS_CBRL_DONE) {
 416                 /* No-op. */
 417                 DEBUG(10, ("State=DONE, returning true\n"));
 418                 return true;
 419         }
 420
 421         SMB_ASSERT(bs->state == ONEFS_CBRL_NONE ||
 422             bs->state == ONEFS_CBRL_ASYNC);
 423
 424         /* A real cancel. */
 425         DEBUG(10, ("Calling ifs_cbrl(CANCEL)..."));
 426         error = ifs_cbrl(fd, CBRL_OP_CANCEL, CBRL_NOTYPE, plock->start,
 427             plock->size, CBRL_NOTYPE, bs->id, plock->context.smbpid,
 428             plock->context.tid);
 429         if (error) {
 430                 DEBUG(10, ("returning false\n"));
 431                 bs->state = ONEFS_CBRL_ERROR;
 432                 return false;
 433         }
 434
 435         bs->state = ONEFS_CBRL_DONE;
 436         onefs_cbrl_enumerate_blq("onefs_brl_cancel_windows");
 437         DEBUG(10, ("returning true\n"));
 438         return true;
 439 }
 440
 441 /* TODO Optimization: Abstract out brl_get_locks() in the Windows case.
 442  * We'll malloc some memory or whatever (can't return NULL), but not actually
 443  * touch the TDB. */
 444
 445 /* XXX brl_locktest: CBRL does not support calling this, but its only for
 446  * strict locking. Add empty VOP? */
 447
 448 /* XXX brl_lockquery: CBRL does not support calling this for WINDOWS LOCKS, but
 449  * its only called for POSIX LOCKS. Add empty VOP? */
 450
 451 /* XXX brl_close_fnum: CBRL will do this automatically. I think this is a NO-OP
 452  * for us, we could add an empty VOP. */
 453