sys/vfs/hammer/hammer_flusher.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/vfs/hammer/hammer_flusher.c,v 1.23 2008/06/10 08:51:01 dillon Exp $
  35  */
  36 /*
  37  * HAMMER dependancy flusher thread
  38  *
  39  * Meta data updates create buffer dependancies which are arranged as a
  40  * hierarchy of lists.
  41  */
  42
  43 #include "hammer.h"
  44
  45 static void hammer_flusher_master_thread(void *arg);
  46 static void hammer_flusher_slave_thread(void *arg);
  47 static void hammer_flusher_clean_loose_ios(hammer_mount_t hmp);
  48 static void hammer_flusher_flush(hammer_mount_t hmp);
  49 static void hammer_flusher_flush_inode(hammer_inode_t ip,
  50                                         hammer_transaction_t trans);
  51 static int hammer_must_finalize_undo(hammer_mount_t hmp);
  52 static void hammer_flusher_finalize(hammer_transaction_t trans, int final);
  53
  54 #define HAMMER_FLUSHER_IMMEDIATE        16
  55
  56 void
  57 hammer_flusher_sync(hammer_mount_t hmp)
  58 {
  59         int seq;
  60
  61         if (hmp->flusher.td) {
  62                 seq = hmp->flusher.next;
  63                 if (hmp->flusher.signal++ == 0)
  64                         wakeup(&hmp->flusher.signal);
  65                 while ((int)(seq - hmp->flusher.done) > 0)
  66                         tsleep(&hmp->flusher.done, 0, "hmrfls", 0);
  67         }
  68 }
  69
  70 void
  71 hammer_flusher_async(hammer_mount_t hmp)
  72 {
  73         if (hmp->flusher.td) {
  74                 if (hmp->flusher.signal++ == 0)
  75                         wakeup(&hmp->flusher.signal);
  76         }
  77 }
  78
  79 void
  80 hammer_flusher_create(hammer_mount_t hmp)
  81 {
  82         hammer_flusher_info_t info;
  83         int i;
  84
  85         hmp->flusher.signal = 0;
  86         hmp->flusher.act = 0;
  87         hmp->flusher.done = 0;
  88         hmp->flusher.next = 1;
  89         hmp->flusher.count = 0;
  90         hammer_ref(&hmp->flusher.finalize_lock);
  91
  92         lwkt_create(hammer_flusher_master_thread, hmp,
  93                     &hmp->flusher.td, NULL, 0, -1, "hammer-M");
  94         for (i = 0; i < HAMMER_MAX_FLUSHERS; ++i) {
  95                 info = kmalloc(sizeof(*info), M_HAMMER, M_WAITOK|M_ZERO);
  96                 info->hmp = hmp;
  97                 TAILQ_INIT(&info->work_list);
  98                 ++hmp->flusher.count;
  99                 hmp->flusher.info[i] = info;
 100                 lwkt_create(hammer_flusher_slave_thread, info,
 101                             &info->td, NULL, 0, -1, "hammer-S%d", i);
 102         }
 103 }
 104
 105 void
 106 hammer_flusher_destroy(hammer_mount_t hmp)
 107 {
 108         hammer_flusher_info_t info;
 109         int i;
 110
 111         /*
 112          * Kill the master
 113          */
 114         hmp->flusher.exiting = 1;
 115         while (hmp->flusher.td) {
 116                 ++hmp->flusher.signal;
 117                 wakeup(&hmp->flusher.signal);
 118                 tsleep(&hmp->flusher.exiting, 0, "hmrwex", hz);
 119         }
 120
 121         /*
 122          * Kill the slaves
 123          */
 124         for (i = 0; i < HAMMER_MAX_FLUSHERS; ++i) {
 125                 if ((info = hmp->flusher.info[i]) != NULL) {
 126                         KKASSERT(info->running == 0);
 127                         info->running = -1;
 128                         wakeup(&info->running);
 129                         while (info->td) {
 130                                 tsleep(&info->td, 0, "hmrwwc", 0);
 131                         }
 132                         hmp->flusher.info[i] = NULL;
 133                         kfree(info, M_HAMMER);
 134                         --hmp->flusher.count;
 135                 }
 136         }
 137         KKASSERT(hmp->flusher.count == 0);
 138 }
 139
 140 static void
 141 hammer_flusher_master_thread(void *arg)
 142 {
 143         hammer_mount_t hmp = arg;
 144
 145         for (;;) {
 146                 while (hmp->flusher.group_lock)
 147                         tsleep(&hmp->flusher.group_lock, 0, "hmrhld", 0);
 148                 kprintf("S");
 149                 hmp->flusher.act = hmp->flusher.next;
 150                 ++hmp->flusher.next;
 151                 hammer_flusher_clean_loose_ios(hmp);
 152                 hammer_flusher_flush(hmp);
 153                 hammer_flusher_clean_loose_ios(hmp);
 154                 hmp->flusher.done = hmp->flusher.act;
 155                 wakeup(&hmp->flusher.done);
 156
 157                 /*
 158                  * Wait for activity.
 159                  */
 160                 if (hmp->flusher.exiting && TAILQ_EMPTY(&hmp->flush_list))
 161                         break;
 162
 163                 /*
 164                  * This is a hack until we can dispose of frontend buffer
 165                  * cache buffers on the frontend.
 166                  */
 167                 while (hmp->flusher.signal == 0)
 168                         tsleep(&hmp->flusher.signal, 0, "hmrwwa", 0);
 169                 hmp->flusher.signal = 0;
 170         }
 171
 172         /*
 173          * And we are done.
 174          */
 175         hmp->flusher.td = NULL;
 176         wakeup(&hmp->flusher.exiting);
 177         lwkt_exit();
 178 }
 179
 180 static void
 181 hammer_flusher_slave_thread(void *arg)
 182 {
 183         hammer_flusher_info_t info;
 184         hammer_mount_t hmp;
 185         hammer_inode_t ip;
 186
 187         info = arg;
 188         hmp = info->hmp;
 189
 190         for (;;) {
 191                 while (info->running == 0)
 192                         tsleep(&info->running, 0, "hmrssw", 0);
 193                 if (info->running < 0)
 194                         break;
 195                 while ((ip = TAILQ_FIRST(&info->work_list)) != NULL) {
 196                         TAILQ_REMOVE(&info->work_list, ip, flush_entry);
 197                         hammer_flusher_flush_inode(ip, &hmp->flusher.trans);
 198                 }
 199                 info->running = 0;
 200                 if (--hmp->flusher.running == 0)
 201                         wakeup(&hmp->flusher.running);
 202         }
 203         info->td = NULL;
 204         wakeup(&info->td);
 205         lwkt_exit();
 206 }
 207
 208 static void
 209 hammer_flusher_clean_loose_ios(hammer_mount_t hmp)
 210 {
 211         hammer_buffer_t buffer;
 212         hammer_io_t io;
 213
 214         /*
 215          * loose ends - buffers without bp's aren't tracked by the kernel
 216          * and can build up, so clean them out.  This can occur when an
 217          * IO completes on a buffer with no references left.
 218          */
 219         while ((io = TAILQ_FIRST(&hmp->lose_list)) != NULL) {
 220                 KKASSERT(io->mod_list == &hmp->lose_list);
 221                 TAILQ_REMOVE(io->mod_list, io, mod_entry);
 222                 io->mod_list = NULL;
 223                 hammer_ref(&io->lock);
 224                 buffer = (void *)io;
 225                 hammer_rel_buffer(buffer, 0);
 226         }
 227 }
 228
 229 /*
 230  * Flush all inodes in the current flush group.
 231  */
 232 static void
 233 hammer_flusher_flush(hammer_mount_t hmp)
 234 {
 235         hammer_flusher_info_t info;
 236         hammer_inode_t ip;
 237         hammer_reserve_t resv;
 238         int i;
 239
 240         /*
 241          * Flush the inodes
 242          */
 243         hammer_start_transaction_fls(&hmp->flusher.trans, hmp);
 244         i = 0;
 245         while ((ip = TAILQ_FIRST(&hmp->flush_list)) != NULL) {
 246                 if (ip->flush_group != hmp->flusher.act)
 247                         break;
 248                 TAILQ_REMOVE(&hmp->flush_list, ip, flush_entry);
 249                 info = hmp->flusher.info[i];
 250                 TAILQ_INSERT_TAIL(&info->work_list, ip, flush_entry);
 251                 if (info->running == 0) {
 252                         ++hmp->flusher.running;
 253                         info->running = 1;
 254                         wakeup(&info->running);
 255                 }
 256                 /*hammer_flusher_flush_inode(ip, &trans);*/
 257                 ++i;
 258                 if (i == HAMMER_MAX_FLUSHERS || hmp->flusher.info[i] == NULL)
 259                         i = 0;
 260         }
 261         while (hmp->flusher.running)
 262                 tsleep(&hmp->flusher.running, 0, "hmrfcc", 0);
 263
 264         hammer_flusher_finalize(&hmp->flusher.trans, 1);
 265         hmp->flusher.tid = hmp->flusher.trans.tid;
 266
 267         /*
 268          * Clean up any freed big-blocks (typically zone-2).
 269          * resv->flush_group is typically set several flush groups ahead
 270          * of the free to ensure that the freed block is not reused until
 271          * it can no longer be reused.
 272          */
 273         while ((resv = TAILQ_FIRST(&hmp->delay_list)) != NULL) {
 274                 if (resv->flush_group != hmp->flusher.act)
 275                         break;
 276                 TAILQ_REMOVE(&hmp->delay_list, resv, delay_entry);
 277                 hammer_blockmap_reserve_complete(hmp, resv);
 278         }
 279         hammer_done_transaction(&hmp->flusher.trans);
 280 }
 281
 282 /*
 283  * Flush a single inode that is part of a flush group.
 284  */
 285 static
 286 void
 287 hammer_flusher_flush_inode(hammer_inode_t ip, hammer_transaction_t trans)
 288 {
 289         hammer_mount_t hmp = ip->hmp;
 290
 291         hammer_lock_sh(&hmp->flusher.finalize_lock);
 292         ip->error = hammer_sync_inode(ip);
 293         hammer_flush_inode_done(ip);
 294         hammer_unlock(&hmp->flusher.finalize_lock);
 295         while (hmp->flusher.finalize_want)
 296                 tsleep(&hmp->flusher.finalize_want, 0, "hmrsxx", 0);
 297         if (hammer_must_finalize_undo(hmp)) {
 298                 hmp->flusher.finalize_want = 1;
 299                 hammer_lock_ex(&hmp->flusher.finalize_lock);
 300                 kprintf("HAMMER: Warning: UNDO area too small!");
 301                 hammer_flusher_finalize(trans, 1);
 302                 hammer_unlock(&hmp->flusher.finalize_lock);
 303                 hmp->flusher.finalize_want = 0;
 304                 wakeup(&hmp->flusher.finalize_want);
 305         } else if (trans->hmp->locked_dirty_count +
 306                    trans->hmp->io_running_count > hammer_limit_dirtybufs) {
 307                 hmp->flusher.finalize_want = 1;
 308                 hammer_lock_ex(&hmp->flusher.finalize_lock);
 309                 kprintf("t");
 310                 hammer_flusher_finalize(trans, 0);
 311                 hammer_unlock(&hmp->flusher.finalize_lock);
 312                 hmp->flusher.finalize_want = 0;
 313                 wakeup(&hmp->flusher.finalize_want);
 314         }
 315 }
 316
 317 /*
 318  * If the UNDO area gets over half full we have to flush it.  We can't
 319  * afford the UNDO area becoming completely full as that would break
 320  * the crash recovery atomicy.
 321  */
 322 static
 323 int
 324 hammer_must_finalize_undo(hammer_mount_t hmp)
 325 {
 326         if (hammer_undo_space(hmp) < hammer_undo_max(hmp) / 2) {
 327                 hkprintf("*");
 328                 return(1);
 329         } else {
 330                 return(0);
 331         }
 332 }
 333
 334 /*
 335  * Flush all pending UNDOs, wait for write completion, update the volume
 336  * header with the new UNDO end position, and flush it.  Then
 337  * asynchronously flush the meta-data.
 338  *
 339  * If this is the last finalization in a flush group we also synchronize
 340  * our cached blockmap and set hmp->flusher_undo_start and our cached undo
 341  * fifo first_offset so the next flush resets the FIFO pointers.
 342  */
 343 static
 344 void
 345 hammer_flusher_finalize(hammer_transaction_t trans, int final)
 346 {
 347         hammer_volume_t root_volume;
 348         hammer_blockmap_t cundomap, dundomap;
 349         hammer_mount_t hmp;
 350         hammer_io_t io;
 351         int count;
 352         int i;
 353
 354         hmp = trans->hmp;
 355         root_volume = trans->rootvol;
 356
 357         /*
 358          * Flush data buffers.  This can occur asynchronously and at any
 359          * time.  We must interlock against the frontend direct-data write
 360          * but do not have to acquire the sync-lock yet.
 361          */
 362         count = 0;
 363         while ((io = TAILQ_FIRST(&hmp->data_list)) != NULL) {
 364                 hammer_ref(&io->lock);
 365                 hammer_io_write_interlock(io);
 366                 KKASSERT(io->type != HAMMER_STRUCTURE_VOLUME);
 367                 hammer_io_flush(io);
 368                 hammer_io_done_interlock(io);
 369                 hammer_rel_buffer((hammer_buffer_t)io, 0);
 370                 ++count;
 371         }
 372
 373         /*
 374          * The sync-lock is required for the remaining sequence.  This lock
 375          * prevents meta-data from being modified.
 376          */
 377         hammer_sync_lock_ex(trans);
 378
 379         /*
 380          * If we have been asked to finalize the volume header sync the
 381          * cached blockmap to the on-disk blockmap.  Generate an UNDO
 382          * record for the update.
 383          */
 384         if (final) {
 385                 cundomap = &hmp->blockmap[0];
 386                 dundomap = &root_volume->ondisk->vol0_blockmap[0];
 387                 if (root_volume->io.modified) {
 388                         hammer_modify_volume(trans, root_volume,
 389                                              dundomap, sizeof(hmp->blockmap));
 390                         for (i = 0; i < HAMMER_MAX_ZONES; ++i)
 391                                 hammer_crc_set_blockmap(&cundomap[i]);
 392                         bcopy(cundomap, dundomap, sizeof(hmp->blockmap));
 393                         hammer_modify_volume_done(root_volume);
 394                 }
 395         }
 396
 397         /*
 398          * Flush UNDOs
 399          */
 400         count = 0;
 401         while ((io = TAILQ_FIRST(&hmp->undo_list)) != NULL) {
 402                 KKASSERT(io->modify_refs == 0);
 403                 hammer_ref(&io->lock);
 404                 KKASSERT(io->type != HAMMER_STRUCTURE_VOLUME);
 405                 hammer_io_flush(io);
 406                 hammer_rel_buffer((hammer_buffer_t)io, 0);
 407                 ++count;
 408         }
 409
 410         /*
 411          * Wait for I/Os to complete
 412          */
 413         crit_enter();
 414         while (hmp->io_running_count)
 415                 tsleep(&hmp->io_running_count, 0, "hmrfl1", 0);
 416         crit_exit();
 417
 418         /*
 419          * Update the on-disk volume header with new UNDO FIFO end position
 420          * (do not generate new UNDO records for this change).  We have to
 421          * do this for the UNDO FIFO whether (final) is set or not.
 422          *
 423          * Also update the on-disk next_tid field.  This does not require
 424          * an UNDO.  However, because our TID is generated before we get
 425          * the sync lock another sync may have beat us to the punch.
 426          *
 427          * The volume header will be flushed out synchronously.
 428          */
 429         dundomap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX];
 430         cundomap = &hmp->blockmap[HAMMER_ZONE_UNDO_INDEX];
 431
 432         if (dundomap->first_offset != cundomap->first_offset ||
 433             dundomap->next_offset != cundomap->next_offset) {
 434                 hammer_modify_volume(NULL, root_volume, NULL, 0);
 435                 dundomap->first_offset = cundomap->first_offset;
 436                 dundomap->next_offset = cundomap->next_offset;
 437                 hammer_crc_set_blockmap(dundomap);
 438                 hammer_crc_set_volume(root_volume->ondisk);
 439                 if (root_volume->ondisk->vol0_next_tid < trans->tid)
 440                         root_volume->ondisk->vol0_next_tid = trans->tid;
 441                 hammer_modify_volume_done(root_volume);
 442         }
 443
 444         if (root_volume->io.modified) {
 445                 hammer_io_flush(&root_volume->io);
 446         }
 447
 448         /*
 449          * Wait for I/Os to complete
 450          */
 451         crit_enter();
 452         while (hmp->io_running_count)
 453                 tsleep(&hmp->io_running_count, 0, "hmrfl2", 0);
 454         crit_exit();
 455
 456         /*
 457          * Flush meta-data.  The meta-data will be undone if we crash
 458          * so we can safely flush it asynchronously.
 459          *
 460          * Repeated catchups will wind up flushing this update's meta-data
 461          * and the UNDO buffers for the next update simultaniously.  This
 462          * is ok.
 463          */
 464         count = 0;
 465         while ((io = TAILQ_FIRST(&hmp->meta_list)) != NULL) {
 466                 KKASSERT(io->modify_refs == 0);
 467                 hammer_ref(&io->lock);
 468                 KKASSERT(io->type != HAMMER_STRUCTURE_VOLUME);
 469                 hammer_io_flush(io);
 470                 hammer_rel_buffer((hammer_buffer_t)io, 0);
 471                 ++count;
 472         }
 473
 474         /*
 475          * If this is the final finalization for the flush group set
 476          * up for the next sequence by setting a new first_offset in
 477          * our cached blockmap and
 478          * clearing the undo history.
 479          */
 480         if (final) {
 481                 cundomap = &hmp->blockmap[HAMMER_ZONE_UNDO_INDEX];
 482                 cundomap->first_offset = cundomap->next_offset;
 483                 hammer_clear_undo_history(hmp);
 484         }
 485
 486         hammer_sync_unlock(trans);
 487 }
 488