sys/geom/journal/g_journal.c

   1 /*-
   2  * Copyright (c) 2005-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/kernel.h>
  33 #include <sys/module.h>
  34 #include <sys/limits.h>
  35 #include <sys/lock.h>
  36 #include <sys/mutex.h>
  37 #include <sys/bio.h>
  38 #include <sys/sysctl.h>
  39 #include <sys/malloc.h>
  40 #include <sys/mount.h>
  41 #include <sys/eventhandler.h>
  42 #include <sys/proc.h>
  43 #include <sys/kthread.h>
  44 #include <sys/sched.h>
  45 #include <sys/taskqueue.h>
  46 #include <sys/vnode.h>
  47 #include <sys/sbuf.h>
  48 #ifdef GJ_MEMDEBUG
  49 #include <sys/stack.h>
  50 #include <sys/kdb.h>
  51 #endif
  52 #include <vm/vm.h>
  53 #include <vm/vm_kern.h>
  54 #include <geom/geom.h>
  55
  56 #include <geom/journal/g_journal.h>
  57
  58 FEATURE(geom_journal, "GEOM journaling support");
  59
  60 /*
  61  * On-disk journal format:
  62  *
  63  * JH - Journal header
  64  * RH - Record header
  65  *
  66  * %%%%%% ****** +------+ +------+     ****** +------+     %%%%%%
  67  * % JH % * RH * | Data | | Data | ... * RH * | Data | ... % JH % ...
  68  * %%%%%% ****** +------+ +------+     ****** +------+     %%%%%%
  69  *
  70  */
  71
  72 CTASSERT(sizeof(struct g_journal_header) <= 512);
  73 CTASSERT(sizeof(struct g_journal_record_header) <= 512);
  74
  75 static MALLOC_DEFINE(M_JOURNAL, "journal_data", "GEOM_JOURNAL Data");
  76 static struct mtx g_journal_cache_mtx;
  77 MTX_SYSINIT(g_journal_cache, &g_journal_cache_mtx, "cache usage", MTX_DEF);
  78
  79 const struct g_journal_desc *g_journal_filesystems[] = {
  80         &g_journal_ufs,
  81         NULL
  82 };
  83
  84 SYSCTL_DECL(_kern_geom);
  85
  86 int g_journal_debug = 0;
  87 static u_int g_journal_switch_time = 10;
  88 static u_int g_journal_force_switch = 70;
  89 static u_int g_journal_parallel_flushes = 16;
  90 static u_int g_journal_parallel_copies = 16;
  91 static u_int g_journal_accept_immediately = 64;
  92 static u_int g_journal_record_entries = GJ_RECORD_HEADER_NENTRIES;
  93 static u_int g_journal_do_optimize = 1;
  94
  95 static SYSCTL_NODE(_kern_geom, OID_AUTO, journal, CTLFLAG_RW, 0,
  96     "GEOM_JOURNAL stuff");
  97 SYSCTL_INT(_kern_geom_journal, OID_AUTO, debug, CTLFLAG_RWTUN, &g_journal_debug, 0,
  98     "Debug level");
  99 SYSCTL_UINT(_kern_geom_journal, OID_AUTO, switch_time, CTLFLAG_RW,
 100     &g_journal_switch_time, 0, "Switch journals every N seconds");
 101 SYSCTL_UINT(_kern_geom_journal, OID_AUTO, force_switch, CTLFLAG_RW,
 102     &g_journal_force_switch, 0, "Force switch when journal is N% full");
 103 SYSCTL_UINT(_kern_geom_journal, OID_AUTO, parallel_flushes, CTLFLAG_RW,
 104     &g_journal_parallel_flushes, 0,
 105     "Number of flush I/O requests to send in parallel");
 106 SYSCTL_UINT(_kern_geom_journal, OID_AUTO, accept_immediately, CTLFLAG_RW,
 107     &g_journal_accept_immediately, 0,
 108     "Number of I/O requests accepted immediately");
 109 SYSCTL_UINT(_kern_geom_journal, OID_AUTO, parallel_copies, CTLFLAG_RW,
 110     &g_journal_parallel_copies, 0,
 111     "Number of copy I/O requests to send in parallel");
 112 static int
 113 g_journal_record_entries_sysctl(SYSCTL_HANDLER_ARGS)
 114 {
 115         u_int entries;
 116         int error;
 117
 118         entries = g_journal_record_entries;
 119         error = sysctl_handle_int(oidp, &entries, 0, req);
 120         if (error != 0 || req->newptr == NULL)
 121                 return (error);
 122         if (entries < 1 || entries > GJ_RECORD_HEADER_NENTRIES)
 123                 return (EINVAL);
 124         g_journal_record_entries = entries;
 125         return (0);
 126 }
 127 SYSCTL_PROC(_kern_geom_journal, OID_AUTO, record_entries,
 128     CTLTYPE_UINT | CTLFLAG_RW, NULL, 0, g_journal_record_entries_sysctl, "I",
 129     "Maximum number of entires in one journal record");
 130 SYSCTL_UINT(_kern_geom_journal, OID_AUTO, optimize, CTLFLAG_RW,
 131     &g_journal_do_optimize, 0, "Try to combine bios on flush and copy");
 132
 133 static u_long g_journal_cache_used = 0;
 134 static u_long g_journal_cache_limit = 64 * 1024 * 1024;
 135 static u_int g_journal_cache_divisor = 2;
 136 static u_int g_journal_cache_switch = 90;
 137 static u_int g_journal_cache_misses = 0;
 138 static u_int g_journal_cache_alloc_failures = 0;
 139 static u_long g_journal_cache_low = 0;
 140
 141 static SYSCTL_NODE(_kern_geom_journal, OID_AUTO, cache, CTLFLAG_RW, 0,
 142     "GEOM_JOURNAL cache");
 143 SYSCTL_ULONG(_kern_geom_journal_cache, OID_AUTO, used, CTLFLAG_RD,
 144     &g_journal_cache_used, 0, "Number of allocated bytes");
 145 static int
 146 g_journal_cache_limit_sysctl(SYSCTL_HANDLER_ARGS)
 147 {
 148         u_long limit;
 149         int error;
 150
 151         limit = g_journal_cache_limit;
 152         error = sysctl_handle_long(oidp, &limit, 0, req);
 153         if (error != 0 || req->newptr == NULL)
 154                 return (error);
 155         g_journal_cache_limit = limit;
 156         g_journal_cache_low = (limit / 100) * g_journal_cache_switch;
 157         return (0);
 158 }
 159 SYSCTL_PROC(_kern_geom_journal_cache, OID_AUTO, limit,
 160     CTLTYPE_ULONG | CTLFLAG_RWTUN, NULL, 0, g_journal_cache_limit_sysctl, "I",
 161     "Maximum number of allocated bytes");
 162 SYSCTL_UINT(_kern_geom_journal_cache, OID_AUTO, divisor, CTLFLAG_RDTUN,
 163     &g_journal_cache_divisor, 0,
 164     "(kmem_size / kern.geom.journal.cache.divisor) == cache size");
 165 static int
 166 g_journal_cache_switch_sysctl(SYSCTL_HANDLER_ARGS)
 167 {
 168         u_int cswitch;
 169         int error;
 170
 171         cswitch = g_journal_cache_switch;
 172         error = sysctl_handle_int(oidp, &cswitch, 0, req);
 173         if (error != 0 || req->newptr == NULL)
 174                 return (error);
 175         if (cswitch > 100)
 176                 return (EINVAL);
 177         g_journal_cache_switch = cswitch;
 178         g_journal_cache_low = (g_journal_cache_limit / 100) * cswitch;
 179         return (0);
 180 }
 181 SYSCTL_PROC(_kern_geom_journal_cache, OID_AUTO, switch,
 182     CTLTYPE_UINT | CTLFLAG_RW, NULL, 0, g_journal_cache_switch_sysctl, "I",
 183     "Force switch when we hit this percent of cache use");
 184 SYSCTL_UINT(_kern_geom_journal_cache, OID_AUTO, misses, CTLFLAG_RW,
 185     &g_journal_cache_misses, 0, "Number of cache misses");
 186 SYSCTL_UINT(_kern_geom_journal_cache, OID_AUTO, alloc_failures, CTLFLAG_RW,
 187     &g_journal_cache_alloc_failures, 0, "Memory allocation failures");
 188
 189 static u_long g_journal_stats_bytes_skipped = 0;
 190 static u_long g_journal_stats_combined_ios = 0;
 191 static u_long g_journal_stats_switches = 0;
 192 static u_long g_journal_stats_wait_for_copy = 0;
 193 static u_long g_journal_stats_journal_full = 0;
 194 static u_long g_journal_stats_low_mem = 0;
 195
 196 static SYSCTL_NODE(_kern_geom_journal, OID_AUTO, stats, CTLFLAG_RW, 0,
 197     "GEOM_JOURNAL statistics");
 198 SYSCTL_ULONG(_kern_geom_journal_stats, OID_AUTO, skipped_bytes, CTLFLAG_RW,
 199     &g_journal_stats_bytes_skipped, 0, "Number of skipped bytes");
 200 SYSCTL_ULONG(_kern_geom_journal_stats, OID_AUTO, combined_ios, CTLFLAG_RW,
 201     &g_journal_stats_combined_ios, 0, "Number of combined I/O requests");
 202 SYSCTL_ULONG(_kern_geom_journal_stats, OID_AUTO, switches, CTLFLAG_RW,
 203     &g_journal_stats_switches, 0, "Number of journal switches");
 204 SYSCTL_ULONG(_kern_geom_journal_stats, OID_AUTO, wait_for_copy, CTLFLAG_RW,
 205     &g_journal_stats_wait_for_copy, 0, "Wait for journal copy on switch");
 206 SYSCTL_ULONG(_kern_geom_journal_stats, OID_AUTO, journal_full, CTLFLAG_RW,
 207     &g_journal_stats_journal_full, 0,
 208     "Number of times journal was almost full.");
 209 SYSCTL_ULONG(_kern_geom_journal_stats, OID_AUTO, low_mem, CTLFLAG_RW,
 210     &g_journal_stats_low_mem, 0, "Number of times low_mem hook was called.");
 211
 212 static g_taste_t g_journal_taste;
 213 static g_ctl_req_t g_journal_config;
 214 static g_dumpconf_t g_journal_dumpconf;
 215 static g_init_t g_journal_init;
 216 static g_fini_t g_journal_fini;
 217
 218 struct g_class g_journal_class = {
 219         .name = G_JOURNAL_CLASS_NAME,
 220         .version = G_VERSION,
 221         .taste = g_journal_taste,
 222         .ctlreq = g_journal_config,
 223         .dumpconf = g_journal_dumpconf,
 224         .init = g_journal_init,
 225         .fini = g_journal_fini
 226 };
 227
 228 static int g_journal_destroy(struct g_journal_softc *sc);
 229 static void g_journal_metadata_update(struct g_journal_softc *sc);
 230 static void g_journal_start_switcher(struct g_class *mp);
 231 static void g_journal_stop_switcher(void);
 232 static void g_journal_switch_wait(struct g_journal_softc *sc);
 233
 234 #define GJ_SWITCHER_WORKING     0
 235 #define GJ_SWITCHER_DIE         1
 236 #define GJ_SWITCHER_DIED        2
 237 static struct proc *g_journal_switcher_proc = NULL;
 238 static int g_journal_switcher_state = GJ_SWITCHER_WORKING;
 239 static int g_journal_switcher_wokenup = 0;
 240 static int g_journal_sync_requested = 0;
 241
 242 #ifdef GJ_MEMDEBUG
 243 struct meminfo {
 244         size_t          mi_size;
 245         struct stack    mi_stack;
 246 };
 247 #endif
 248
 249 /*
 250  * We use our own malloc/realloc/free funtions, so we can collect statistics
 251  * and force journal switch when we're running out of cache.
 252  */
 253 static void *
 254 gj_malloc(size_t size, int flags)
 255 {
 256         void *p;
 257 #ifdef GJ_MEMDEBUG
 258         struct meminfo *mi;
 259 #endif
 260
 261         mtx_lock(&g_journal_cache_mtx);
 262         if (g_journal_cache_limit > 0 && !g_journal_switcher_wokenup &&
 263             g_journal_cache_used + size > g_journal_cache_low) {
 264                 GJ_DEBUG(1, "No cache, waking up the switcher.");
 265                 g_journal_switcher_wokenup = 1;
 266                 wakeup(&g_journal_switcher_state);
 267         }
 268         if ((flags & M_NOWAIT) && g_journal_cache_limit > 0 &&
 269             g_journal_cache_used + size > g_journal_cache_limit) {
 270                 mtx_unlock(&g_journal_cache_mtx);
 271                 g_journal_cache_alloc_failures++;
 272                 return (NULL);
 273         }
 274         g_journal_cache_used += size;
 275         mtx_unlock(&g_journal_cache_mtx);
 276         flags &= ~M_NOWAIT;
 277 #ifndef GJ_MEMDEBUG
 278         p = malloc(size, M_JOURNAL, flags | M_WAITOK);
 279 #else
 280         mi = malloc(sizeof(*mi) + size, M_JOURNAL, flags | M_WAITOK);
 281         p = (u_char *)mi + sizeof(*mi);
 282         mi->mi_size = size;
 283         stack_save(&mi->mi_stack);
 284 #endif
 285         return (p);
 286 }
 287
 288 static void
 289 gj_free(void *p, size_t size)
 290 {
 291 #ifdef GJ_MEMDEBUG
 292         struct meminfo *mi;
 293 #endif
 294
 295         KASSERT(p != NULL, ("p=NULL"));
 296         KASSERT(size > 0, ("size=0"));
 297         mtx_lock(&g_journal_cache_mtx);
 298         KASSERT(g_journal_cache_used >= size, ("Freeing too much?"));
 299         g_journal_cache_used -= size;
 300         mtx_unlock(&g_journal_cache_mtx);
 301 #ifdef GJ_MEMDEBUG
 302         mi = p = (void *)((u_char *)p - sizeof(*mi));
 303         if (mi->mi_size != size) {
 304                 printf("GJOURNAL: Size mismatch! %zu != %zu\n", size,
 305                     mi->mi_size);
 306                 printf("GJOURNAL: Alloc backtrace:\n");
 307                 stack_print(&mi->mi_stack);
 308                 printf("GJOURNAL: Free backtrace:\n");
 309                 kdb_backtrace();
 310         }
 311 #endif
 312         free(p, M_JOURNAL);
 313 }
 314
 315 static void *
 316 gj_realloc(void *p, size_t size, size_t oldsize)
 317 {
 318         void *np;
 319
 320 #ifndef GJ_MEMDEBUG
 321         mtx_lock(&g_journal_cache_mtx);
 322         g_journal_cache_used -= oldsize;
 323         g_journal_cache_used += size;
 324         mtx_unlock(&g_journal_cache_mtx);
 325         np = realloc(p, size, M_JOURNAL, M_WAITOK);
 326 #else
 327         np = gj_malloc(size, M_WAITOK);
 328         bcopy(p, np, MIN(oldsize, size));
 329         gj_free(p, oldsize);
 330 #endif
 331         return (np);
 332 }
 333
 334 static void
 335 g_journal_check_overflow(struct g_journal_softc *sc)
 336 {
 337         off_t length, used;
 338
 339         if ((sc->sc_active.jj_offset < sc->sc_inactive.jj_offset &&
 340              sc->sc_journal_offset >= sc->sc_inactive.jj_offset) ||
 341             (sc->sc_active.jj_offset > sc->sc_inactive.jj_offset &&
 342              sc->sc_journal_offset >= sc->sc_inactive.jj_offset &&
 343              sc->sc_journal_offset < sc->sc_active.jj_offset)) {
 344                 panic("Journal overflow "
 345                     "(id = %u joffset=%jd active=%jd inactive=%jd)",
 346                     (unsigned)sc->sc_id,
 347                     (intmax_t)sc->sc_journal_offset,
 348                     (intmax_t)sc->sc_active.jj_offset,
 349                     (intmax_t)sc->sc_inactive.jj_offset);
 350         }
 351         if (sc->sc_active.jj_offset < sc->sc_inactive.jj_offset) {
 352                 length = sc->sc_inactive.jj_offset - sc->sc_active.jj_offset;
 353                 used = sc->sc_journal_offset - sc->sc_active.jj_offset;
 354         } else {
 355                 length = sc->sc_jend - sc->sc_active.jj_offset;
 356                 length += sc->sc_inactive.jj_offset - sc->sc_jstart;
 357                 if (sc->sc_journal_offset >= sc->sc_active.jj_offset)
 358                         used = sc->sc_journal_offset - sc->sc_active.jj_offset;
 359                 else {
 360                         used = sc->sc_jend - sc->sc_active.jj_offset;
 361                         used += sc->sc_journal_offset - sc->sc_jstart;
 362                 }
 363         }
 364         /* Already woken up? */
 365         if (g_journal_switcher_wokenup)
 366                 return;
 367         /*
 368          * If the active journal takes more than g_journal_force_switch precent
 369          * of free journal space, we force journal switch.
 370          */
 371         KASSERT(length > 0,
 372             ("length=%jd used=%jd active=%jd inactive=%jd joffset=%jd",
 373             (intmax_t)length, (intmax_t)used,
 374             (intmax_t)sc->sc_active.jj_offset,
 375             (intmax_t)sc->sc_inactive.jj_offset,
 376             (intmax_t)sc->sc_journal_offset));
 377         if ((used * 100) / length > g_journal_force_switch) {
 378                 g_journal_stats_journal_full++;
 379                 GJ_DEBUG(1, "Journal %s %jd%% full, forcing journal switch.",
 380                     sc->sc_name, (used * 100) / length);
 381                 mtx_lock(&g_journal_cache_mtx);
 382                 g_journal_switcher_wokenup = 1;
 383                 wakeup(&g_journal_switcher_state);
 384                 mtx_unlock(&g_journal_cache_mtx);
 385         }
 386 }
 387
 388 static void
 389 g_journal_orphan(struct g_consumer *cp)
 390 {
 391         struct g_journal_softc *sc;
 392         char name[256];
 393         int error;
 394
 395         g_topology_assert();
 396         sc = cp->geom->softc;
 397         strlcpy(name, cp->provider->name, sizeof(name));
 398         GJ_DEBUG(0, "Lost provider %s.", name);
 399         if (sc == NULL)
 400                 return;
 401         error = g_journal_destroy(sc);
 402         if (error == 0)
 403                 GJ_DEBUG(0, "Journal %s destroyed.", name);
 404         else {
 405                 GJ_DEBUG(0, "Cannot destroy journal %s (error=%d). "
 406                     "Destroy it manually after last close.", sc->sc_name,
 407                     error);
 408         }
 409 }
 410
 411 static int
 412 g_journal_access(struct g_provider *pp, int acr, int acw, int ace)
 413 {
 414         struct g_journal_softc *sc;
 415         int dcr, dcw, dce;
 416
 417         g_topology_assert();
 418         GJ_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name,
 419             acr, acw, ace);
 420
 421         dcr = pp->acr + acr;
 422         dcw = pp->acw + acw;
 423         dce = pp->ace + ace;
 424
 425         sc = pp->geom->softc;
 426         if (sc == NULL || (sc->sc_flags & GJF_DEVICE_DESTROY)) {
 427                 if (acr <= 0 && acw <= 0 && ace <= 0)
 428                         return (0);
 429                 else
 430                         return (ENXIO);
 431         }
 432         if (pp->acw == 0 && dcw > 0) {
 433                 GJ_DEBUG(1, "Marking %s as dirty.", sc->sc_name);
 434                 sc->sc_flags &= ~GJF_DEVICE_CLEAN;
 435                 g_topology_unlock();
 436                 g_journal_metadata_update(sc);
 437                 g_topology_lock();
 438         } /* else if (pp->acw == 0 && dcw > 0 && JEMPTY(sc)) {
 439                 GJ_DEBUG(1, "Marking %s as clean.", sc->sc_name);
 440                 sc->sc_flags |= GJF_DEVICE_CLEAN;
 441                 g_topology_unlock();
 442                 g_journal_metadata_update(sc);
 443                 g_topology_lock();
 444         } */
 445         return (0);
 446 }
 447
 448 static void
 449 g_journal_header_encode(struct g_journal_header *hdr, u_char *data)
 450 {
 451
 452         bcopy(GJ_HEADER_MAGIC, data, sizeof(GJ_HEADER_MAGIC));
 453         data += sizeof(GJ_HEADER_MAGIC);
 454         le32enc(data, hdr->jh_journal_id);
 455         data += 4;
 456         le32enc(data, hdr->jh_journal_next_id);
 457 }
 458
 459 static int
 460 g_journal_header_decode(const u_char *data, struct g_journal_header *hdr)
 461 {
 462
 463         bcopy(data, hdr->jh_magic, sizeof(hdr->jh_magic));
 464         data += sizeof(hdr->jh_magic);
 465         if (bcmp(hdr->jh_magic, GJ_HEADER_MAGIC, sizeof(GJ_HEADER_MAGIC)) != 0)
 466                 return (EINVAL);
 467         hdr->jh_journal_id = le32dec(data);
 468         data += 4;
 469         hdr->jh_journal_next_id = le32dec(data);
 470         return (0);
 471 }
 472
 473 static void
 474 g_journal_flush_cache(struct g_journal_softc *sc)
 475 {
 476         struct bintime bt;
 477         int error;
 478
 479         if (sc->sc_bio_flush == 0)
 480                 return;
 481         GJ_TIMER_START(1, &bt);
 482         if (sc->sc_bio_flush & GJ_FLUSH_JOURNAL) {
 483                 error = g_io_flush(sc->sc_jconsumer);
 484                 GJ_DEBUG(error == 0 ? 2 : 0, "Flush cache of %s: error=%d.",
 485                     sc->sc_jconsumer->provider->name, error);
 486         }
 487         if (sc->sc_bio_flush & GJ_FLUSH_DATA) {
 488                 /*
 489                  * TODO: This could be called in parallel with the
 490                  *       previous call.
 491                  */
 492                 error = g_io_flush(sc->sc_dconsumer);
 493                 GJ_DEBUG(error == 0 ? 2 : 0, "Flush cache of %s: error=%d.",
 494                     sc->sc_dconsumer->provider->name, error);
 495         }
 496         GJ_TIMER_STOP(1, &bt, "Cache flush time");
 497 }
 498
 499 static int
 500 g_journal_write_header(struct g_journal_softc *sc)
 501 {
 502         struct g_journal_header hdr;
 503         struct g_consumer *cp;
 504         u_char *buf;
 505         int error;
 506
 507         cp = sc->sc_jconsumer;
 508         buf = gj_malloc(cp->provider->sectorsize, M_WAITOK);
 509
 510         strlcpy(hdr.jh_magic, GJ_HEADER_MAGIC, sizeof(hdr.jh_magic));
 511         hdr.jh_journal_id = sc->sc_journal_id;
 512         hdr.jh_journal_next_id = sc->sc_journal_next_id;
 513         g_journal_header_encode(&hdr, buf);
 514         error = g_write_data(cp, sc->sc_journal_offset, buf,
 515             cp->provider->sectorsize);
 516         /* if (error == 0) */
 517         sc->sc_journal_offset += cp->provider->sectorsize;
 518
 519         gj_free(buf, cp->provider->sectorsize);
 520         return (error);
 521 }
 522
 523 /*
 524  * Every journal record has a header and data following it.
 525  * Functions below are used to decode the header before storing it to
 526  * little endian and to encode it after reading to system endianness.
 527  */
 528 static void
 529 g_journal_record_header_encode(struct g_journal_record_header *hdr,
 530     u_char *data)
 531 {
 532         struct g_journal_entry *ent;
 533         u_int i;
 534
 535         bcopy(GJ_RECORD_HEADER_MAGIC, data, sizeof(GJ_RECORD_HEADER_MAGIC));
 536         data += sizeof(GJ_RECORD_HEADER_MAGIC);
 537         le32enc(data, hdr->jrh_journal_id);
 538         data += 8;
 539         le16enc(data, hdr->jrh_nentries);
 540         data += 2;
 541         bcopy(hdr->jrh_sum, data, sizeof(hdr->jrh_sum));
 542         data += 8;
 543         for (i = 0; i < hdr->jrh_nentries; i++) {
 544                 ent = &hdr->jrh_entries[i];
 545                 le64enc(data, ent->je_joffset);
 546                 data += 8;
 547                 le64enc(data, ent->je_offset);
 548                 data += 8;
 549                 le64enc(data, ent->je_length);
 550                 data += 8;
 551         }
 552 }
 553
 554 static int
 555 g_journal_record_header_decode(const u_char *data,
 556     struct g_journal_record_header *hdr)
 557 {
 558         struct g_journal_entry *ent;
 559         u_int i;
 560
 561         bcopy(data, hdr->jrh_magic, sizeof(hdr->jrh_magic));
 562         data += sizeof(hdr->jrh_magic);
 563         if (strcmp(hdr->jrh_magic, GJ_RECORD_HEADER_MAGIC) != 0)
 564                 return (EINVAL);
 565         hdr->jrh_journal_id = le32dec(data);
 566         data += 8;
 567         hdr->jrh_nentries = le16dec(data);
 568         data += 2;
 569         if (hdr->jrh_nentries > GJ_RECORD_HEADER_NENTRIES)
 570                 return (EINVAL);
 571         bcopy(data, hdr->jrh_sum, sizeof(hdr->jrh_sum));
 572         data += 8;
 573         for (i = 0; i < hdr->jrh_nentries; i++) {
 574                 ent = &hdr->jrh_entries[i];
 575                 ent->je_joffset = le64dec(data);
 576                 data += 8;
 577                 ent->je_offset = le64dec(data);
 578                 data += 8;
 579                 ent->je_length = le64dec(data);
 580                 data += 8;
 581         }
 582         return (0);
 583 }
 584
 585 /*
 586  * Function reads metadata from a provider (via the given consumer), decodes
 587  * it to system endianness and verifies its correctness.
 588  */
 589 static int
 590 g_journal_metadata_read(struct g_consumer *cp, struct g_journal_metadata *md)
 591 {
 592         struct g_provider *pp;
 593         u_char *buf;
 594         int error;
 595
 596         g_topology_assert();
 597
 598         error = g_access(cp, 1, 0, 0);
 599         if (error != 0)
 600                 return (error);
 601         pp = cp->provider;
 602         g_topology_unlock();
 603         /* Metadata is stored in last sector. */
 604         buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
 605             &error);
 606         g_topology_lock();
 607         g_access(cp, -1, 0, 0);
 608         if (buf == NULL) {
 609                 GJ_DEBUG(1, "Cannot read metadata from %s (error=%d).",
 610                     cp->provider->name, error);
 611                 return (error);
 612         }
 613
 614         /* Decode metadata. */
 615         error = journal_metadata_decode(buf, md);
 616         g_free(buf);
 617         /* Is this is gjournal provider at all? */
 618         if (strcmp(md->md_magic, G_JOURNAL_MAGIC) != 0)
 619                 return (EINVAL);
 620         /*
 621          * Are we able to handle this version of metadata?
 622          * We only maintain backward compatibility.
 623          */
 624         if (md->md_version > G_JOURNAL_VERSION) {
 625                 GJ_DEBUG(0,
 626                     "Kernel module is too old to handle metadata from %s.",
 627                     cp->provider->name);
 628                 return (EINVAL);
 629         }
 630         /* Is checksum correct? */
 631         if (error != 0) {
 632                 GJ_DEBUG(0, "MD5 metadata hash mismatch for provider %s.",
 633                     cp->provider->name);
 634                 return (error);
 635         }
 636         return (0);
 637 }
 638
 639 /*
 640  * Two functions below are responsible for updating metadata.
 641  * Only metadata on the data provider is updated (we need to update
 642  * information about active journal in there).
 643  */
 644 static void
 645 g_journal_metadata_done(struct bio *bp)
 646 {
 647
 648         /*
 649          * There is not much we can do on error except informing about it.
 650          */
 651         if (bp->bio_error != 0) {
 652                 GJ_LOGREQ(0, bp, "Cannot update metadata (error=%d).",
 653                     bp->bio_error);
 654         } else {
 655                 GJ_LOGREQ(2, bp, "Metadata updated.");
 656         }
 657         gj_free(bp->bio_data, bp->bio_length);
 658         g_destroy_bio(bp);
 659 }
 660
 661 static void
 662 g_journal_metadata_update(struct g_journal_softc *sc)
 663 {
 664         struct g_journal_metadata md;
 665         struct g_consumer *cp;
 666         struct bio *bp;
 667         u_char *sector;
 668
 669         cp = sc->sc_dconsumer;
 670         sector = gj_malloc(cp->provider->sectorsize, M_WAITOK);
 671         strlcpy(md.md_magic, G_JOURNAL_MAGIC, sizeof(md.md_magic));
 672         md.md_version = G_JOURNAL_VERSION;
 673         md.md_id = sc->sc_id;
 674         md.md_type = sc->sc_orig_type;
 675         md.md_jstart = sc->sc_jstart;
 676         md.md_jend = sc->sc_jend;
 677         md.md_joffset = sc->sc_inactive.jj_offset;
 678         md.md_jid = sc->sc_journal_previous_id;
 679         md.md_flags = 0;
 680         if (sc->sc_flags & GJF_DEVICE_CLEAN)
 681                 md.md_flags |= GJ_FLAG_CLEAN;
 682
 683         if (sc->sc_flags & GJF_DEVICE_HARDCODED)
 684                 strlcpy(md.md_provider, sc->sc_name, sizeof(md.md_provider));
 685         else
 686                 bzero(md.md_provider, sizeof(md.md_provider));
 687         md.md_provsize = cp->provider->mediasize;
 688         journal_metadata_encode(&md, sector);
 689
 690         /*
 691          * Flush the cache, so we know all data are on disk.
 692          * We write here informations like "journal is consistent", so we need
 693          * to be sure it is. Without BIO_FLUSH here, we can end up in situation
 694          * where metadata is stored on disk, but not all data.
 695          */
 696         g_journal_flush_cache(sc);
 697
 698         bp = g_alloc_bio();
 699         bp->bio_offset = cp->provider->mediasize - cp->provider->sectorsize;
 700         bp->bio_length = cp->provider->sectorsize;
 701         bp->bio_data = sector;
 702         bp->bio_cmd = BIO_WRITE;
 703         if (!(sc->sc_flags & GJF_DEVICE_DESTROY)) {
 704                 bp->bio_done = g_journal_metadata_done;
 705                 g_io_request(bp, cp);
 706         } else {
 707                 bp->bio_done = NULL;
 708                 g_io_request(bp, cp);
 709                 biowait(bp, "gjmdu");
 710                 g_journal_metadata_done(bp);
 711         }
 712
 713         /*
 714          * Be sure metadata reached the disk.
 715          */
 716         g_journal_flush_cache(sc);
 717 }
 718
 719 /*
 720  * This is where the I/O request comes from the GEOM.
 721  */
 722 static void
 723 g_journal_start(struct bio *bp)
 724 {
 725         struct g_journal_softc *sc;
 726
 727         sc = bp->bio_to->geom->softc;
 728         GJ_LOGREQ(3, bp, "Request received.");
 729
 730         switch (bp->bio_cmd) {
 731         case BIO_READ:
 732         case BIO_WRITE:
 733                 mtx_lock(&sc->sc_mtx);
 734                 bioq_insert_tail(&sc->sc_regular_queue, bp);
 735                 wakeup(sc);
 736                 mtx_unlock(&sc->sc_mtx);
 737                 return;
 738         case BIO_GETATTR:
 739                 if (strcmp(bp->bio_attribute, "GJOURNAL::provider") == 0) {
 740                         strlcpy(bp->bio_data, bp->bio_to->name, bp->bio_length);
 741                         bp->bio_completed = strlen(bp->bio_to->name) + 1;
 742                         g_io_deliver(bp, 0);
 743                         return;
 744                 }
 745                 /* FALLTHROUGH */
 746         case BIO_DELETE:
 747         default:
 748                 g_io_deliver(bp, EOPNOTSUPP);
 749                 return;
 750         }
 751 }
 752
 753 static void
 754 g_journal_std_done(struct bio *bp)
 755 {
 756         struct g_journal_softc *sc;
 757
 758         sc = bp->bio_from->geom->softc;
 759         mtx_lock(&sc->sc_mtx);
 760         bioq_insert_tail(&sc->sc_back_queue, bp);
 761         wakeup(sc);
 762         mtx_unlock(&sc->sc_mtx);
 763 }
 764
 765 static struct bio *
 766 g_journal_new_bio(off_t start, off_t end, off_t joffset, u_char *data,
 767     int flags)
 768 {
 769         struct bio *bp;
 770
 771         bp = g_alloc_bio();
 772         bp->bio_offset = start;
 773         bp->bio_joffset = joffset;
 774         bp->bio_length = end - start;
 775         bp->bio_cmd = BIO_WRITE;
 776         bp->bio_done = g_journal_std_done;
 777         if (data == NULL)
 778                 bp->bio_data = NULL;
 779         else {
 780                 bp->bio_data = gj_malloc(bp->bio_length, flags);
 781                 if (bp->bio_data != NULL)
 782                         bcopy(data, bp->bio_data, bp->bio_length);
 783         }
 784         return (bp);
 785 }
 786
 787 #define g_journal_insert_bio(head, bp, flags)                           \
 788         g_journal_insert((head), (bp)->bio_offset,                      \
 789                 (bp)->bio_offset + (bp)->bio_length, (bp)->bio_joffset, \
 790                 (bp)->bio_data, flags)
 791 /*
 792  * The function below does a lot more than just inserting bio to the queue.
 793  * It keeps the queue sorted by offset and ensures that there are no doubled
 794  * data (it combines bios where ranges overlap).
 795  *
 796  * The function returns the number of bios inserted (as bio can be splitted).
 797  */
 798 static int
 799 g_journal_insert(struct bio **head, off_t nstart, off_t nend, off_t joffset,
 800     u_char *data, int flags)
 801 {
 802         struct bio *nbp, *cbp, *pbp;
 803         off_t cstart, cend;
 804         u_char *tmpdata;
 805         int n;
 806
 807         GJ_DEBUG(3, "INSERT(%p): (%jd, %jd, %jd)", *head, nstart, nend,
 808             joffset);
 809         n = 0;
 810         pbp = NULL;
 811         GJQ_FOREACH(*head, cbp) {
 812                 cstart = cbp->bio_offset;
 813                 cend = cbp->bio_offset + cbp->bio_length;
 814
 815                 if (nstart >= cend) {
 816                         /*
 817                          *  +-------------+
 818                          *  |             |
 819                          *  |   current   |  +-------------+
 820                          *  |     bio     |  |             |
 821                          *  |             |  |     new     |
 822                          *  +-------------+  |     bio     |
 823                          *                   |             |
 824                          *                   +-------------+
 825                          */
 826                         GJ_DEBUG(3, "INSERT(%p): 1", *head);
 827                 } else if (nend <= cstart) {
 828                         /*
 829                          *                   +-------------+
 830                          *                   |             |
 831                          *  +-------------+  |   current   |
 832                          *  |             |  |     bio     |
 833                          *  |     new     |  |             |
 834                          *  |     bio     |  +-------------+
 835                          *  |             |
 836                          *  +-------------+
 837                          */
 838                         nbp = g_journal_new_bio(nstart, nend, joffset, data,
 839                             flags);
 840                         if (pbp == NULL)
 841                                 *head = nbp;
 842                         else
 843                                 pbp->bio_next = nbp;
 844                         nbp->bio_next = cbp;
 845                         n++;
 846                         GJ_DEBUG(3, "INSERT(%p): 2 (nbp=%p pbp=%p)", *head, nbp,
 847                             pbp);
 848                         goto end;
 849                 } else if (nstart <= cstart && nend >= cend) {
 850                         /*
 851                          *      +-------------+      +-------------+
 852                          *      | current bio |      | current bio |
 853                          *  +---+-------------+---+  +-------------+---+
 854                          *  |   |             |   |  |             |   |
 855                          *  |   |             |   |  |             |   |
 856                          *  |   +-------------+   |  +-------------+   |
 857                          *  |       new bio       |  |     new bio     |
 858                          *  +---------------------+  +-----------------+
 859                          *
 860                          *      +-------------+  +-------------+
 861                          *      | current bio |  | current bio |
 862                          *  +---+-------------+  +-------------+
 863                          *  |   |             |  |             |
 864                          *  |   |             |  |             |
 865                          *  |   +-------------+  +-------------+
 866                          *  |     new bio     |  |   new bio   |
 867                          *  +-----------------+  +-------------+
 868                          */
 869                         g_journal_stats_bytes_skipped += cbp->bio_length;
 870                         cbp->bio_offset = nstart;
 871                         cbp->bio_joffset = joffset;
 872                         cbp->bio_length = cend - nstart;
 873                         if (cbp->bio_data != NULL) {
 874                                 gj_free(cbp->bio_data, cend - cstart);
 875                                 cbp->bio_data = NULL;
 876                         }
 877                         if (data != NULL) {
 878                                 cbp->bio_data = gj_malloc(cbp->bio_length,
 879                                     flags);
 880                                 if (cbp->bio_data != NULL) {
 881                                         bcopy(data, cbp->bio_data,
 882                                             cbp->bio_length);
 883                                 }
 884                                 data += cend - nstart;
 885                         }
 886                         joffset += cend - nstart;
 887                         nstart = cend;
 888                         GJ_DEBUG(3, "INSERT(%p): 3 (cbp=%p)", *head, cbp);
 889                 } else if (nstart > cstart && nend >= cend) {
 890                         /*
 891                          *  +-----------------+  +-------------+
 892                          *  |   current bio   |  | current bio |
 893                          *  |   +-------------+  |   +---------+---+
 894                          *  |   |             |  |   |         |   |
 895                          *  |   |             |  |   |         |   |
 896                          *  +---+-------------+  +---+---------+   |
 897                          *      |   new bio   |      |   new bio   |
 898                          *      +-------------+      +-------------+
 899                          */
 900                         g_journal_stats_bytes_skipped += cend - nstart;
 901                         nbp = g_journal_new_bio(nstart, cend, joffset, data,
 902                             flags);
 903                         nbp->bio_next = cbp->bio_next;
 904                         cbp->bio_next = nbp;
 905                         cbp->bio_length = nstart - cstart;
 906                         if (cbp->bio_data != NULL) {
 907                                 cbp->bio_data = gj_realloc(cbp->bio_data,
 908                                     cbp->bio_length, cend - cstart);
 909                         }
 910                         if (data != NULL)
 911                                 data += cend - nstart;
 912                         joffset += cend - nstart;
 913                         nstart = cend;
 914                         n++;
 915                         GJ_DEBUG(3, "INSERT(%p): 4 (cbp=%p)", *head, cbp);
 916                 } else if (nstart > cstart && nend < cend) {
 917                         /*
 918                          *  +---------------------+
 919                          *  |     current bio     |
 920                          *  |   +-------------+   |
 921                          *  |   |             |   |
 922                          *  |   |             |   |
 923                          *  +---+-------------+---+
 924                          *      |   new bio   |
 925                          *      +-------------+
 926                          */
 927                         g_journal_stats_bytes_skipped += nend - nstart;
 928                         nbp = g_journal_new_bio(nstart, nend, joffset, data,
 929                             flags);
 930                         nbp->bio_next = cbp->bio_next;
 931                         cbp->bio_next = nbp;
 932                         if (cbp->bio_data == NULL)
 933                                 tmpdata = NULL;
 934                         else
 935                                 tmpdata = cbp->bio_data + nend - cstart;
 936                         nbp = g_journal_new_bio(nend, cend,
 937                             cbp->bio_joffset + nend - cstart, tmpdata, flags);
 938                         nbp->bio_next = ((struct bio *)cbp->bio_next)->bio_next;
 939                         ((struct bio *)cbp->bio_next)->bio_next = nbp;
 940                         cbp->bio_length = nstart - cstart;
 941                         if (cbp->bio_data != NULL) {
 942                                 cbp->bio_data = gj_realloc(cbp->bio_data,
 943                                     cbp->bio_length, cend - cstart);
 944                         }
 945                         n += 2;
 946                         GJ_DEBUG(3, "INSERT(%p): 5 (cbp=%p)", *head, cbp);
 947                         goto end;
 948                 } else if (nstart <= cstart && nend < cend) {
 949                         /*
 950                          *  +-----------------+      +-------------+
 951                          *  |   current bio   |      | current bio |
 952                          *  +-------------+   |  +---+---------+   |
 953                          *  |             |   |  |   |         |   |
 954                          *  |             |   |  |   |         |   |
 955                          *  +-------------+---+  |   +---------+---+
 956                          *  |   new bio   |      |   new bio   |
 957                          *  +-------------+      +-------------+
 958                          */
 959                         g_journal_stats_bytes_skipped += nend - nstart;
 960                         nbp = g_journal_new_bio(nstart, nend, joffset, data,
 961                             flags);
 962                         if (pbp == NULL)
 963                                 *head = nbp;
 964                         else
 965                                 pbp->bio_next = nbp;
 966                         nbp->bio_next = cbp;
 967                         cbp->bio_offset = nend;
 968                         cbp->bio_length = cend - nend;
 969                         cbp->bio_joffset += nend - cstart;
 970                         tmpdata = cbp->bio_data;
 971                         if (tmpdata != NULL) {
 972                                 cbp->bio_data = gj_malloc(cbp->bio_length,
 973                                     flags);
 974                                 if (cbp->bio_data != NULL) {
 975                                         bcopy(tmpdata + nend - cstart,
 976                                             cbp->bio_data, cbp->bio_length);
 977                                 }
 978                                 gj_free(tmpdata, cend - cstart);
 979                         }
 980                         n++;
 981                         GJ_DEBUG(3, "INSERT(%p): 6 (cbp=%p)", *head, cbp);
 982                         goto end;
 983                 }
 984                 if (nstart == nend)
 985                         goto end;
 986                 pbp = cbp;
 987         }
 988         nbp = g_journal_new_bio(nstart, nend, joffset, data, flags);
 989         if (pbp == NULL)
 990                 *head = nbp;
 991         else
 992                 pbp->bio_next = nbp;
 993         nbp->bio_next = NULL;
 994         n++;
 995         GJ_DEBUG(3, "INSERT(%p): 8 (nbp=%p pbp=%p)", *head, nbp, pbp);
 996 end:
 997         if (g_journal_debug >= 3) {
 998                 GJQ_FOREACH(*head, cbp) {
 999                         GJ_DEBUG(3, "ELEMENT: %p (%jd, %jd, %jd, %p)", cbp,
1000                             (intmax_t)cbp->bio_offset,
1001                             (intmax_t)cbp->bio_length,
1002                             (intmax_t)cbp->bio_joffset, cbp->bio_data);
1003                 }
1004                 GJ_DEBUG(3, "INSERT(%p): DONE %d", *head, n);
1005         }
1006         return (n);
1007 }
1008
1009 /*
1010  * The function combines neighbour bios trying to squeeze as much data as
1011  * possible into one bio.
1012  *
1013  * The function returns the number of bios combined (negative value).
1014  */
1015 static int
1016 g_journal_optimize(struct bio *head)
1017 {
1018         struct bio *cbp, *pbp;
1019         int n;
1020
1021         n = 0;
1022         pbp = NULL;
1023         GJQ_FOREACH(head, cbp) {
1024                 /* Skip bios which has to be read first. */
1025                 if (cbp->bio_data == NULL) {
1026                         pbp = NULL;
1027                         continue;
1028                 }
1029                 /* There is no previous bio yet. */
1030                 if (pbp == NULL) {
1031                         pbp = cbp;
1032                         continue;
1033                 }
1034                 /* Is this a neighbour bio? */
1035                 if (pbp->bio_offset + pbp->bio_length != cbp->bio_offset) {
1036                         /* Be sure that bios queue is sorted. */
1037                         KASSERT(pbp->bio_offset + pbp->bio_length < cbp->bio_offset,
1038                             ("poffset=%jd plength=%jd coffset=%jd",
1039                             (intmax_t)pbp->bio_offset,
1040                             (intmax_t)pbp->bio_length,
1041                             (intmax_t)cbp->bio_offset));
1042                         pbp = cbp;
1043                         continue;
1044                 }
1045                 /* Be sure we don't end up with too big bio. */
1046                 if (pbp->bio_length + cbp->bio_length > MAXPHYS) {
1047                         pbp = cbp;
1048                         continue;
1049                 }
1050                 /* Ok, we can join bios. */
1051                 GJ_LOGREQ(4, pbp, "Join: ");
1052                 GJ_LOGREQ(4, cbp, "and: ");
1053                 pbp->bio_data = gj_realloc(pbp->bio_data,
1054                     pbp->bio_length + cbp->bio_length, pbp->bio_length);
1055                 bcopy(cbp->bio_data, pbp->bio_data + pbp->bio_length,
1056                     cbp->bio_length);
1057                 gj_free(cbp->bio_data, cbp->bio_length);
1058                 pbp->bio_length += cbp->bio_length;
1059                 pbp->bio_next = cbp->bio_next;
1060                 g_destroy_bio(cbp);
1061                 cbp = pbp;
1062                 g_journal_stats_combined_ios++;
1063                 n--;
1064                 GJ_LOGREQ(4, pbp, "Got: ");
1065         }
1066         return (n);
1067 }
1068
1069 /*
1070  * TODO: Update comment.
1071  * These are functions responsible for copying one portion of data from journal
1072  * to the destination provider.
1073  * The order goes like this:
1074  * 1. Read the header, which contains informations about data blocks
1075  *    following it.
1076  * 2. Read the data blocks from the journal.
1077  * 3. Write the data blocks on the data provider.
1078  *
1079  * g_journal_copy_start()
1080  * g_journal_copy_done() - got finished write request, logs potential errors.
1081  */
1082
1083 /*
1084  * When there is no data in cache, this function is used to read it.
1085  */
1086 static void
1087 g_journal_read_first(struct g_journal_softc *sc, struct bio *bp)
1088 {
1089         struct bio *cbp;
1090
1091         /*
1092          * We were short in memory, so data was freed.
1093          * In that case we need to read it back from journal.
1094          */
1095         cbp = g_alloc_bio();
1096         cbp->bio_cflags = bp->bio_cflags;
1097         cbp->bio_parent = bp;
1098         cbp->bio_offset = bp->bio_joffset;
1099         cbp->bio_length = bp->bio_length;
1100         cbp->bio_data = gj_malloc(bp->bio_length, M_WAITOK);
1101         cbp->bio_cmd = BIO_READ;
1102         cbp->bio_done = g_journal_std_done;
1103         GJ_LOGREQ(4, cbp, "READ FIRST");
1104         g_io_request(cbp, sc->sc_jconsumer);
1105         g_journal_cache_misses++;
1106 }
1107
1108 static void
1109 g_journal_copy_send(struct g_journal_softc *sc)
1110 {
1111         struct bio *bioq, *bp, *lbp;
1112
1113         bioq = lbp = NULL;
1114         mtx_lock(&sc->sc_mtx);
1115         for (; sc->sc_copy_in_progress < g_journal_parallel_copies;) {
1116                 bp = GJQ_FIRST(sc->sc_inactive.jj_queue);
1117                 if (bp == NULL)
1118                         break;
1119                 GJQ_REMOVE(sc->sc_inactive.jj_queue, bp);
1120                 sc->sc_copy_in_progress++;
1121                 GJQ_INSERT_AFTER(bioq, bp, lbp);
1122                 lbp = bp;
1123         }
1124         mtx_unlock(&sc->sc_mtx);
1125         if (g_journal_do_optimize)
1126                 sc->sc_copy_in_progress += g_journal_optimize(bioq);
1127         while ((bp = GJQ_FIRST(bioq)) != NULL) {
1128                 GJQ_REMOVE(bioq, bp);
1129                 GJQ_INSERT_HEAD(sc->sc_copy_queue, bp);
1130                 bp->bio_cflags = GJ_BIO_COPY;
1131                 if (bp->bio_data == NULL)
1132                         g_journal_read_first(sc, bp);
1133                 else {
1134                         bp->bio_joffset = 0;
1135                         GJ_LOGREQ(4, bp, "SEND");
1136                         g_io_request(bp, sc->sc_dconsumer);
1137                 }
1138         }
1139 }
1140
1141 static void
1142 g_journal_copy_start(struct g_journal_softc *sc)
1143 {
1144
1145         /*
1146          * Remember in metadata that we're starting to copy journaled data
1147          * to the data provider.
1148          * In case of power failure, we will copy these data once again on boot.
1149          */
1150         if (!sc->sc_journal_copying) {
1151                 sc->sc_journal_copying = 1;
1152                 GJ_DEBUG(1, "Starting copy of journal.");
1153                 g_journal_metadata_update(sc);
1154         }
1155         g_journal_copy_send(sc);
1156 }
1157
1158 /*
1159  * Data block has been read from the journal provider.
1160  */
1161 static int
1162 g_journal_copy_read_done(struct bio *bp)
1163 {
1164         struct g_journal_softc *sc;
1165         struct g_consumer *cp;
1166         struct bio *pbp;
1167
1168         KASSERT(bp->bio_cflags == GJ_BIO_COPY,
1169             ("Invalid bio (%d != %d).", bp->bio_cflags, GJ_BIO_COPY));
1170
1171         sc = bp->bio_from->geom->softc;
1172         pbp = bp->bio_parent;
1173
1174         if (bp->bio_error != 0) {
1175                 GJ_DEBUG(0, "Error while reading data from %s (error=%d).",
1176                     bp->bio_to->name, bp->bio_error);
1177                 /*
1178                  * We will not be able to deliver WRITE request as well.
1179                  */
1180                 gj_free(bp->bio_data, bp->bio_length);
1181                 g_destroy_bio(pbp);
1182                 g_destroy_bio(bp);
1183                 sc->sc_copy_in_progress--;
1184                 return (1);
1185         }
1186         pbp->bio_data = bp->bio_data;
1187         cp = sc->sc_dconsumer;
1188         g_io_request(pbp, cp);
1189         GJ_LOGREQ(4, bp, "READ DONE");
1190         g_destroy_bio(bp);
1191         return (0);
1192 }
1193
1194 /*
1195  * Data block has been written to the data provider.
1196  */
1197 static void
1198 g_journal_copy_write_done(struct bio *bp)
1199 {
1200         struct g_journal_softc *sc;
1201
1202         KASSERT(bp->bio_cflags == GJ_BIO_COPY,
1203             ("Invalid bio (%d != %d).", bp->bio_cflags, GJ_BIO_COPY));
1204
1205         sc = bp->bio_from->geom->softc;
1206         sc->sc_copy_in_progress--;
1207
1208         if (bp->bio_error != 0) {
1209                 GJ_LOGREQ(0, bp, "[copy] Error while writing data (error=%d)",
1210                     bp->bio_error);
1211         }
1212         GJQ_REMOVE(sc->sc_copy_queue, bp);
1213         gj_free(bp->bio_data, bp->bio_length);
1214         GJ_LOGREQ(4, bp, "DONE");
1215         g_destroy_bio(bp);
1216
1217         if (sc->sc_copy_in_progress == 0) {
1218                 /*
1219                  * This was the last write request for this journal.
1220                  */
1221                 GJ_DEBUG(1, "Data has been copied.");
1222                 sc->sc_journal_copying = 0;
1223         }
1224 }
1225
1226 static void g_journal_flush_done(struct bio *bp);
1227
1228 /*
1229  * Flush one record onto active journal provider.
1230  */
1231 static void
1232 g_journal_flush(struct g_journal_softc *sc)
1233 {
1234         struct g_journal_record_header hdr;
1235         struct g_journal_entry *ent;
1236         struct g_provider *pp;
1237         struct bio **bioq;
1238         struct bio *bp, *fbp, *pbp;
1239         off_t joffset;
1240         u_char *data, hash[16];
1241         MD5_CTX ctx;
1242         u_int i;
1243
1244         if (sc->sc_current_count == 0)
1245                 return;
1246
1247         pp = sc->sc_jprovider;
1248         GJ_VALIDATE_OFFSET(sc->sc_journal_offset, sc);
1249         joffset = sc->sc_journal_offset;
1250
1251         GJ_DEBUG(2, "Storing %d journal entries on %s at %jd.",
1252             sc->sc_current_count, pp->name, (intmax_t)joffset);
1253
1254         /*
1255          * Store 'journal id', so we know to which journal this record belongs.
1256          */
1257         hdr.jrh_journal_id = sc->sc_journal_id;
1258         /* Could be less than g_journal_record_entries if called due timeout. */
1259         hdr.jrh_nentries = MIN(sc->sc_current_count, g_journal_record_entries);
1260         strlcpy(hdr.jrh_magic, GJ_RECORD_HEADER_MAGIC, sizeof(hdr.jrh_magic));
1261
1262         bioq = &sc->sc_active.jj_queue;
1263         GJQ_LAST(sc->sc_flush_queue, pbp);
1264
1265         fbp = g_alloc_bio();
1266         fbp->bio_parent = NULL;
1267         fbp->bio_cflags = GJ_BIO_JOURNAL;
1268         fbp->bio_offset = -1;
1269         fbp->bio_joffset = joffset;
1270         fbp->bio_length = pp->sectorsize;
1271         fbp->bio_cmd = BIO_WRITE;
1272         fbp->bio_done = g_journal_std_done;
1273         GJQ_INSERT_AFTER(sc->sc_flush_queue, fbp, pbp);
1274         pbp = fbp;
1275         fbp->bio_to = pp;
1276         GJ_LOGREQ(4, fbp, "FLUSH_OUT");
1277         joffset += pp->sectorsize;
1278         sc->sc_flush_count++;
1279         if (sc->sc_flags & GJF_DEVICE_CHECKSUM)
1280                 MD5Init(&ctx);
1281
1282         for (i = 0; i < hdr.jrh_nentries; i++) {
1283                 bp = sc->sc_current_queue;
1284                 KASSERT(bp != NULL, ("NULL bp"));
1285                 bp->bio_to = pp;
1286                 GJ_LOGREQ(4, bp, "FLUSHED");
1287                 sc->sc_current_queue = bp->bio_next;
1288                 bp->bio_next = NULL;
1289                 sc->sc_current_count--;
1290
1291                 /* Add to the header. */
1292                 ent = &hdr.jrh_entries[i];
1293                 ent->je_offset = bp->bio_offset;
1294                 ent->je_joffset = joffset;
1295                 ent->je_length = bp->bio_length;
1296
1297                 data = bp->bio_data;
1298                 if (sc->sc_flags & GJF_DEVICE_CHECKSUM)
1299                         MD5Update(&ctx, data, ent->je_length);
1300                 g_reset_bio(bp);
1301                 bp->bio_cflags = GJ_BIO_JOURNAL;
1302                 bp->bio_offset = ent->je_offset;
1303                 bp->bio_joffset = ent->je_joffset;
1304                 bp->bio_length = ent->je_length;
1305                 bp->bio_data = data;
1306                 bp->bio_cmd = BIO_WRITE;
1307                 bp->bio_done = g_journal_std_done;
1308                 GJQ_INSERT_AFTER(sc->sc_flush_queue, bp, pbp);
1309                 pbp = bp;
1310                 bp->bio_to = pp;
1311                 GJ_LOGREQ(4, bp, "FLUSH_OUT");
1312                 joffset += bp->bio_length;
1313                 sc->sc_flush_count++;
1314
1315                 /*
1316                  * Add request to the active sc_journal_queue queue.
1317                  * This is our cache. After journal switch we don't have to
1318                  * read the data from the inactive journal, because we keep
1319                  * it in memory.
1320                  */
1321                 g_journal_insert(bioq, ent->je_offset,
1322                     ent->je_offset + ent->je_length, ent->je_joffset, data,
1323                     M_NOWAIT);
1324         }
1325
1326         /*
1327          * After all requests, store valid header.
1328          */
1329         data = gj_malloc(pp->sectorsize, M_WAITOK);
1330         if (sc->sc_flags & GJF_DEVICE_CHECKSUM) {
1331                 MD5Final(hash, &ctx);
1332                 bcopy(hash, hdr.jrh_sum, sizeof(hdr.jrh_sum));
1333         }
1334         g_journal_record_header_encode(&hdr, data);
1335         fbp->bio_data = data;
1336
1337         sc->sc_journal_offset = joffset;
1338
1339         g_journal_check_overflow(sc);
1340 }
1341
1342 /*
1343  * Flush request finished.
1344  */
1345 static void
1346 g_journal_flush_done(struct bio *bp)
1347 {
1348         struct g_journal_softc *sc;
1349         struct g_consumer *cp;
1350
1351         KASSERT((bp->bio_cflags & GJ_BIO_MASK) == GJ_BIO_JOURNAL,
1352             ("Invalid bio (%d != %d).", bp->bio_cflags, GJ_BIO_JOURNAL));
1353
1354         cp = bp->bio_from;
1355         sc = cp->geom->softc;
1356         sc->sc_flush_in_progress--;
1357
1358         if (bp->bio_error != 0) {
1359                 GJ_LOGREQ(0, bp, "[flush] Error while writing data (error=%d)",
1360                     bp->bio_error);
1361         }
1362         gj_free(bp->bio_data, bp->bio_length);
1363         GJ_LOGREQ(4, bp, "DONE");
1364         g_destroy_bio(bp);
1365 }
1366
1367 static void g_journal_release_delayed(struct g_journal_softc *sc);
1368
1369 static void
1370 g_journal_flush_send(struct g_journal_softc *sc)
1371 {
1372         struct g_consumer *cp;
1373         struct bio *bioq, *bp, *lbp;
1374
1375         cp = sc->sc_jconsumer;
1376         bioq = lbp = NULL;
1377         while (sc->sc_flush_in_progress < g_journal_parallel_flushes) {
1378                 /* Send one flush requests to the active journal. */
1379                 bp = GJQ_FIRST(sc->sc_flush_queue);
1380                 if (bp != NULL) {
1381                         GJQ_REMOVE(sc->sc_flush_queue, bp);
1382                         sc->sc_flush_count--;
1383                         bp->bio_offset = bp->bio_joffset;
1384                         bp->bio_joffset = 0;
1385                         sc->sc_flush_in_progress++;
1386                         GJQ_INSERT_AFTER(bioq, bp, lbp);
1387                         lbp = bp;
1388                 }
1389                 /* Try to release delayed requests. */
1390                 g_journal_release_delayed(sc);
1391                 /* If there are no requests to flush, leave. */
1392                 if (GJQ_FIRST(sc->sc_flush_queue) == NULL)
1393                         break;
1394         }
1395         if (g_journal_do_optimize)
1396                 sc->sc_flush_in_progress += g_journal_optimize(bioq);
1397         while ((bp = GJQ_FIRST(bioq)) != NULL) {
1398                 GJQ_REMOVE(bioq, bp);
1399                 GJ_LOGREQ(3, bp, "Flush request send");
1400                 g_io_request(bp, cp);
1401         }
1402 }
1403
1404 static void
1405 g_journal_add_current(struct g_journal_softc *sc, struct bio *bp)
1406 {
1407         int n;
1408
1409         GJ_LOGREQ(4, bp, "CURRENT %d", sc->sc_current_count);
1410         n = g_journal_insert_bio(&sc->sc_current_queue, bp, M_WAITOK);
1411         sc->sc_current_count += n;
1412         n = g_journal_optimize(sc->sc_current_queue);
1413         sc->sc_current_count += n;
1414         /*
1415          * For requests which are added to the current queue we deliver
1416          * response immediately.
1417          */
1418         bp->bio_completed = bp->bio_length;
1419         g_io_deliver(bp, 0);
1420         if (sc->sc_current_count >= g_journal_record_entries) {
1421                 /*
1422                  * Let's flush one record onto active journal provider.
1423                  */
1424                 g_journal_flush(sc);
1425         }
1426 }
1427
1428 static void
1429 g_journal_release_delayed(struct g_journal_softc *sc)
1430 {
1431         struct bio *bp;
1432
1433         for (;;) {
1434                 /* The flush queue is full, exit. */
1435                 if (sc->sc_flush_count >= g_journal_accept_immediately)
1436                         return;
1437                 bp = bioq_takefirst(&sc->sc_delayed_queue);
1438                 if (bp == NULL)
1439                         return;
1440                 sc->sc_delayed_count--;
1441                 g_journal_add_current(sc, bp);
1442         }
1443 }
1444
1445 /*
1446  * Add I/O request to the current queue. If we have enough requests for one
1447  * journal record we flush them onto active journal provider.
1448  */
1449 static void
1450 g_journal_add_request(struct g_journal_softc *sc, struct bio *bp)
1451 {
1452
1453         /*
1454          * The flush queue is full, we need to delay the request.
1455          */
1456         if (sc->sc_delayed_count > 0 ||
1457             sc->sc_flush_count >= g_journal_accept_immediately) {
1458                 GJ_LOGREQ(4, bp, "DELAYED");
1459                 bioq_insert_tail(&sc->sc_delayed_queue, bp);
1460                 sc->sc_delayed_count++;
1461                 return;
1462         }
1463
1464         KASSERT(TAILQ_EMPTY(&sc->sc_delayed_queue.queue),
1465             ("DELAYED queue not empty."));
1466         g_journal_add_current(sc, bp);
1467 }
1468
1469 static void g_journal_read_done(struct bio *bp);
1470
1471 /*
1472  * Try to find requested data in cache.
1473  */
1474 static struct bio *
1475 g_journal_read_find(struct bio *head, int sorted, struct bio *pbp, off_t ostart,
1476     off_t oend)
1477 {
1478         off_t cstart, cend;
1479         struct bio *bp;
1480
1481         GJQ_FOREACH(head, bp) {
1482                 if (bp->bio_offset == -1)
1483                         continue;
1484                 cstart = MAX(ostart, bp->bio_offset);
1485                 cend = MIN(oend, bp->bio_offset + bp->bio_length);
1486                 if (cend <= ostart)
1487                         continue;
1488                 else if (cstart >= oend) {
1489                         if (!sorted)
1490                                 continue;
1491                         else {
1492                                 bp = NULL;
1493                                 break;
1494                         }
1495                 }
1496                 if (bp->bio_data == NULL)
1497                         break;
1498                 GJ_DEBUG(3, "READ(%p): (%jd, %jd) (bp=%p)", head, cstart, cend,
1499                     bp);
1500                 bcopy(bp->bio_data + cstart - bp->bio_offset,
1501                     pbp->bio_data + cstart - pbp->bio_offset, cend - cstart);
1502                 pbp->bio_completed += cend - cstart;
1503                 if (pbp->bio_completed == pbp->bio_length) {
1504                         /*
1505                          * Cool, the whole request was in cache, deliver happy
1506                          * message.
1507                          */
1508                         g_io_deliver(pbp, 0);
1509                         return (pbp);
1510                 }
1511                 break;
1512         }
1513         return (bp);
1514 }
1515
1516 /*
1517  * This function is used for collecting data on read.
1518  * The complexity is because parts of the data can be stored in four different
1519  * places:
1520  * - in memory - the data not yet send to the active journal provider
1521  * - in the active journal
1522  * - in the inactive journal
1523  * - in the data provider
1524  */
1525 static void
1526 g_journal_read(struct g_journal_softc *sc, struct bio *pbp, off_t ostart,
1527     off_t oend)
1528 {
1529         struct bio *bp, *nbp, *head;
1530         off_t cstart, cend;
1531         u_int i, sorted = 0;
1532
1533         GJ_DEBUG(3, "READ: (%jd, %jd)", ostart, oend);
1534
1535         cstart = cend = -1;
1536         bp = NULL;
1537         head = NULL;
1538         for (i = 1; i <= 5; i++) {
1539                 switch (i) {
1540                 case 1: /* Not-yet-send data. */
1541                         head = sc->sc_current_queue;
1542                         sorted = 1;
1543                         break;
1544                 case 2: /* Skip flush queue as they are also in active queue */
1545                         continue;
1546                 case 3: /* Active journal. */
1547                         head = sc->sc_active.jj_queue;
1548                         sorted = 1;
1549                         break;
1550                 case 4: /* Inactive journal. */
1551                         /*
1552                          * XXX: Here could be a race with g_journal_lowmem().
1553                          */
1554                         head = sc->sc_inactive.jj_queue;
1555                         sorted = 1;
1556                         break;
1557                 case 5: /* In-flight to the data provider. */
1558                         head = sc->sc_copy_queue;
1559                         sorted = 0;
1560                         break;
1561                 default:
1562                         panic("gjournal %s: i=%d", __func__, i);
1563                 }
1564                 bp = g_journal_read_find(head, sorted, pbp, ostart, oend);
1565                 if (bp == pbp) { /* Got the whole request. */
1566                         GJ_DEBUG(2, "Got the whole request from %u.", i);
1567                         return;
1568                 } else if (bp != NULL) {
1569                         cstart = MAX(ostart, bp->bio_offset);
1570                         cend = MIN(oend, bp->bio_offset + bp->bio_length);
1571                         GJ_DEBUG(2, "Got part of the request from %u (%jd-%jd).",
1572                             i, (intmax_t)cstart, (intmax_t)cend);
1573                         break;
1574                 }
1575         }
1576         if (bp != NULL) {
1577                 if (bp->bio_data == NULL) {
1578                         nbp = g_duplicate_bio(pbp);
1579                         nbp->bio_cflags = GJ_BIO_READ;
1580                         nbp->bio_data =
1581                             pbp->bio_data + cstart - pbp->bio_offset;
1582                         nbp->bio_offset =
1583                             bp->bio_joffset + cstart - bp->bio_offset;
1584                         nbp->bio_length = cend - cstart;
1585                         nbp->bio_done = g_journal_read_done;
1586                         g_io_request(nbp, sc->sc_jconsumer);
1587                 }
1588                 /*
1589                  * If we don't have the whole request yet, call g_journal_read()
1590                  * recursively.
1591                  */
1592                 if (ostart < cstart)
1593                         g_journal_read(sc, pbp, ostart, cstart);
1594                 if (oend > cend)
1595                         g_journal_read(sc, pbp, cend, oend);
1596         } else {
1597                 /*
1598                  * No data in memory, no data in journal.
1599                  * Its time for asking data provider.
1600                  */
1601                 GJ_DEBUG(3, "READ(data): (%jd, %jd)", ostart, oend);
1602                 nbp = g_duplicate_bio(pbp);
1603                 nbp->bio_cflags = GJ_BIO_READ;
1604                 nbp->bio_data = pbp->bio_data + ostart - pbp->bio_offset;
1605                 nbp->bio_offset = ostart;
1606                 nbp->bio_length = oend - ostart;
1607                 nbp->bio_done = g_journal_read_done;
1608                 g_io_request(nbp, sc->sc_dconsumer);
1609                 /* We have the whole request, return here. */
1610                 return;
1611         }
1612 }
1613
1614 /*
1615  * Function responsible for handling finished READ requests.
1616  * Actually, g_std_done() could be used here, the only difference is that we
1617  * log error.
1618  */
1619 static void
1620 g_journal_read_done(struct bio *bp)
1621 {
1622         struct bio *pbp;
1623
1624         KASSERT(bp->bio_cflags == GJ_BIO_READ,
1625             ("Invalid bio (%d != %d).", bp->bio_cflags, GJ_BIO_READ));
1626
1627         pbp = bp->bio_parent;
1628         pbp->bio_inbed++;
1629         pbp->bio_completed += bp->bio_length;
1630
1631         if (bp->bio_error != 0) {
1632                 if (pbp->bio_error == 0)
1633                         pbp->bio_error = bp->bio_error;
1634                 GJ_DEBUG(0, "Error while reading data from %s (error=%d).",
1635                     bp->bio_to->name, bp->bio_error);
1636         }
1637         g_destroy_bio(bp);
1638         if (pbp->bio_children == pbp->bio_inbed &&
1639             pbp->bio_completed == pbp->bio_length) {
1640                 /* We're done. */
1641                 g_io_deliver(pbp, 0);
1642         }
1643 }
1644
1645 /*
1646  * Deactive current journal and active next one.
1647  */
1648 static void
1649 g_journal_switch(struct g_journal_softc *sc)
1650 {
1651         struct g_provider *pp;
1652
1653         if (JEMPTY(sc)) {
1654                 GJ_DEBUG(3, "No need for %s switch.", sc->sc_name);
1655                 pp = LIST_FIRST(&sc->sc_geom->provider);
1656                 if (!(sc->sc_flags & GJF_DEVICE_CLEAN) && pp->acw == 0) {
1657                         sc->sc_flags |= GJF_DEVICE_CLEAN;
1658                         GJ_DEBUG(1, "Marking %s as clean.", sc->sc_name);
1659                         g_journal_metadata_update(sc);
1660                 }
1661         } else {
1662                 GJ_DEBUG(3, "Switching journal %s.", sc->sc_geom->name);
1663
1664                 pp = sc->sc_jprovider;
1665
1666                 sc->sc_journal_previous_id = sc->sc_journal_id;
1667
1668                 sc->sc_journal_id = sc->sc_journal_next_id;
1669                 sc->sc_journal_next_id = arc4random();
1670
1671                 GJ_VALIDATE_OFFSET(sc->sc_journal_offset, sc);
1672
1673                 g_journal_write_header(sc);
1674
1675                 sc->sc_inactive.jj_offset = sc->sc_active.jj_offset;
1676                 sc->sc_inactive.jj_queue = sc->sc_active.jj_queue;
1677
1678                 sc->sc_active.jj_offset =
1679                     sc->sc_journal_offset - pp->sectorsize;
1680                 sc->sc_active.jj_queue = NULL;
1681
1682                 /*
1683                  * Switch is done, start copying data from the (now) inactive
1684                  * journal to the data provider.
1685                  */
1686                 g_journal_copy_start(sc);
1687         }
1688         mtx_lock(&sc->sc_mtx);
1689         sc->sc_flags &= ~GJF_DEVICE_SWITCH;
1690         mtx_unlock(&sc->sc_mtx);
1691 }
1692
1693 static void
1694 g_journal_initialize(struct g_journal_softc *sc)
1695 {
1696
1697         sc->sc_journal_id = arc4random();
1698         sc->sc_journal_next_id = arc4random();
1699         sc->sc_journal_previous_id = sc->sc_journal_id;
1700         sc->sc_journal_offset = sc->sc_jstart;
1701         sc->sc_inactive.jj_offset = sc->sc_jstart;
1702         g_journal_write_header(sc);
1703         sc->sc_active.jj_offset = sc->sc_jstart;
1704 }
1705
1706 static void
1707 g_journal_mark_as_dirty(struct g_journal_softc *sc)
1708 {
1709         const struct g_journal_desc *desc;
1710         int i;
1711
1712         GJ_DEBUG(1, "Marking file system %s as dirty.", sc->sc_name);
1713         for (i = 0; (desc = g_journal_filesystems[i]) != NULL; i++)
1714                 desc->jd_dirty(sc->sc_dconsumer);
1715 }
1716
1717 /*
1718  * Function read record header from the given journal.
1719  * It is very simlar to g_read_data(9), but it doesn't allocate memory for bio
1720  * and data on every call.
1721  */
1722 static int
1723 g_journal_sync_read(struct g_consumer *cp, struct bio *bp, off_t offset,
1724     void *data)
1725 {
1726         int error;
1727
1728         g_reset_bio(bp);
1729         bp->bio_cmd = BIO_READ;
1730         bp->bio_done = NULL;
1731         bp->bio_offset = offset;
1732         bp->bio_length = cp->provider->sectorsize;
1733         bp->bio_data = data;
1734         g_io_request(bp, cp);
1735         error = biowait(bp, "gjs_read");
1736         return (error);
1737 }
1738
1739 #if 0
1740 /*
1741  * Function is called when we start the journal device and we detect that
1742  * one of the journals was not fully copied.
1743  * The purpose of this function is to read all records headers from journal
1744  * and placed them in the inactive queue, so we can start journal
1745  * synchronization process and the journal provider itself.
1746  * Design decision was taken to not synchronize the whole journal here as it
1747  * can take too much time. Reading headers only and delaying synchronization
1748  * process until after journal provider is started should be the best choice.
1749  */
1750 #endif
1751
1752 static void
1753 g_journal_sync(struct g_journal_softc *sc)
1754 {
1755         struct g_journal_record_header rhdr;
1756         struct g_journal_entry *ent;
1757         struct g_journal_header jhdr;
1758         struct g_consumer *cp;
1759         struct bio *bp, *fbp, *tbp;
1760         off_t joffset, offset;
1761         u_char *buf, sum[16];
1762         uint64_t id;
1763         MD5_CTX ctx;
1764         int error, found, i;
1765
1766         found = 0;
1767         fbp = NULL;
1768         cp = sc->sc_jconsumer;
1769         bp = g_alloc_bio();
1770         buf = gj_malloc(cp->provider->sectorsize, M_WAITOK);
1771         offset = joffset = sc->sc_inactive.jj_offset = sc->sc_journal_offset;
1772
1773         GJ_DEBUG(2, "Looking for termination at %jd.", (intmax_t)joffset);
1774
1775         /*
1776          * Read and decode first journal header.
1777          */
1778         error = g_journal_sync_read(cp, bp, offset, buf);
1779         if (error != 0) {
1780                 GJ_DEBUG(0, "Error while reading journal header from %s.",
1781                     cp->provider->name);
1782                 goto end;
1783         }
1784         error = g_journal_header_decode(buf, &jhdr);
1785         if (error != 0) {
1786                 GJ_DEBUG(0, "Cannot decode journal header from %s.",
1787                     cp->provider->name);
1788                 goto end;
1789         }
1790         id = sc->sc_journal_id;
1791         if (jhdr.jh_journal_id != sc->sc_journal_id) {
1792                 GJ_DEBUG(1, "Journal ID mismatch at %jd (0x%08x != 0x%08x).",
1793                     (intmax_t)offset, (u_int)jhdr.jh_journal_id, (u_int)id);
1794                 goto end;
1795         }
1796         offset += cp->provider->sectorsize;
1797         id = sc->sc_journal_next_id = jhdr.jh_journal_next_id;
1798
1799         for (;;) {
1800                 /*
1801                  * If the biggest record won't fit, look for a record header or
1802                  * journal header from the beginning.
1803                  */
1804                 GJ_VALIDATE_OFFSET(offset, sc);
1805                 error = g_journal_sync_read(cp, bp, offset, buf);
1806                 if (error != 0) {
1807                         /*
1808                          * Not good. Having an error while reading header
1809                          * means, that we cannot read next headers and in
1810                          * consequence we cannot find termination.
1811                          */
1812                         GJ_DEBUG(0,
1813                             "Error while reading record header from %s.",
1814                             cp->provider->name);
1815                         break;
1816                 }
1817
1818                 error = g_journal_record_header_decode(buf, &rhdr);
1819                 if (error != 0) {
1820                         GJ_DEBUG(2, "Not a record header at %jd (error=%d).",
1821                             (intmax_t)offset, error);
1822                         /*
1823                          * This is not a record header.
1824                          * If we are lucky, this is next journal header.
1825                          */
1826                         error = g_journal_header_decode(buf, &jhdr);
1827                         if (error != 0) {
1828                                 GJ_DEBUG(1, "Not a journal header at %jd (error=%d).",
1829                                     (intmax_t)offset, error);
1830                                 /*
1831                                  * Nope, this is not journal header, which
1832                                  * bascially means that journal is not
1833                                  * terminated properly.
1834                                  */
1835                                 error = ENOENT;
1836                                 break;
1837                         }
1838                         /*
1839                          * Ok. This is header of _some_ journal. Now we need to
1840                          * verify if this is header of the _next_ journal.
1841                          */
1842                         if (jhdr.jh_journal_id != id) {
1843                                 GJ_DEBUG(1, "Journal ID mismatch at %jd "
1844                                     "(0x%08x != 0x%08x).", (intmax_t)offset,
1845                                     (u_int)jhdr.jh_journal_id, (u_int)id);
1846                                 error = ENOENT;
1847                                 break;
1848                         }
1849
1850                         /* Found termination. */
1851                         found++;
1852                         GJ_DEBUG(1, "Found termination at %jd (id=0x%08x).",
1853                             (intmax_t)offset, (u_int)id);
1854                         sc->sc_active.jj_offset = offset;
1855                         sc->sc_journal_offset =
1856                             offset + cp->provider->sectorsize;
1857                         sc->sc_journal_id = id;
1858                         id = sc->sc_journal_next_id = jhdr.jh_journal_next_id;
1859
1860                         while ((tbp = fbp) != NULL) {
1861                                 fbp = tbp->bio_next;
1862                                 GJ_LOGREQ(3, tbp, "Adding request.");
1863                                 g_journal_insert_bio(&sc->sc_inactive.jj_queue,
1864                                     tbp, M_WAITOK);
1865                         }
1866
1867                         /* Skip journal's header. */
1868                         offset += cp->provider->sectorsize;
1869                         continue;
1870                 }
1871
1872                 /* Skip record's header. */
1873                 offset += cp->provider->sectorsize;
1874
1875                 /*
1876                  * Add information about every record entry to the inactive
1877                  * queue.
1878                  */
1879                 if (sc->sc_flags & GJF_DEVICE_CHECKSUM)
1880                         MD5Init(&ctx);
1881                 for (i = 0; i < rhdr.jrh_nentries; i++) {
1882                         ent = &rhdr.jrh_entries[i];
1883                         GJ_DEBUG(3, "Insert entry: %jd %jd.",
1884                             (intmax_t)ent->je_offset, (intmax_t)ent->je_length);
1885                         g_journal_insert(&fbp, ent->je_offset,
1886                             ent->je_offset + ent->je_length, ent->je_joffset,
1887                             NULL, M_WAITOK);
1888                         if (sc->sc_flags & GJF_DEVICE_CHECKSUM) {
1889                                 u_char *buf2;
1890
1891                                 /*
1892                                  * TODO: Should use faster function (like
1893                                  *       g_journal_sync_read()).
1894                                  */
1895                                 buf2 = g_read_data(cp, offset, ent->je_length,
1896                                     NULL);
1897                                 if (buf2 == NULL)
1898                                         GJ_DEBUG(0, "Cannot read data at %jd.",
1899                                             (intmax_t)offset);
1900                                 else {
1901                                         MD5Update(&ctx, buf2, ent->je_length);
1902                                         g_free(buf2);
1903                                 }
1904                         }
1905                         /* Skip entry's data. */
1906                         offset += ent->je_length;
1907                 }
1908                 if (sc->sc_flags & GJF_DEVICE_CHECKSUM) {
1909                         MD5Final(sum, &ctx);
1910                         if (bcmp(sum, rhdr.jrh_sum, sizeof(rhdr.jrh_sum)) != 0) {
1911                                 GJ_DEBUG(0, "MD5 hash mismatch at %jd!",
1912                                     (intmax_t)offset);
1913                         }
1914                 }
1915         }
1916 end:
1917         gj_free(bp->bio_data, cp->provider->sectorsize);
1918         g_destroy_bio(bp);
1919
1920         /* Remove bios from unterminated journal. */
1921         while ((tbp = fbp) != NULL) {
1922                 fbp = tbp->bio_next;
1923                 g_destroy_bio(tbp);
1924         }
1925
1926         if (found < 1 && joffset > 0) {
1927                 GJ_DEBUG(0, "Journal on %s is broken/corrupted. Initializing.",
1928                     sc->sc_name);
1929                 while ((tbp = sc->sc_inactive.jj_queue) != NULL) {
1930                         sc->sc_inactive.jj_queue = tbp->bio_next;
1931                         g_destroy_bio(tbp);
1932                 }
1933                 g_journal_initialize(sc);
1934                 g_journal_mark_as_dirty(sc);
1935         } else {
1936                 GJ_DEBUG(0, "Journal %s consistent.", sc->sc_name);
1937                 g_journal_copy_start(sc);
1938         }
1939 }
1940
1941 /*
1942  * Wait for requests.
1943  * If we have requests in the current queue, flush them after 3 seconds from the
1944  * last flush. In this way we don't wait forever (or for journal switch) with
1945  * storing not full records on journal.
1946  */
1947 static void
1948 g_journal_wait(struct g_journal_softc *sc, time_t last_write)
1949 {
1950         int error, timeout;
1951
1952         GJ_DEBUG(3, "%s: enter", __func__);
1953         if (sc->sc_current_count == 0) {
1954                 if (g_journal_debug < 2)
1955                         msleep(sc, &sc->sc_mtx, PRIBIO | PDROP, "gj:work", 0);
1956                 else {
1957                         /*
1958                          * If we have debug turned on, show number of elements
1959                          * in various queues.
1960                          */
1961                         for (;;) {
1962                                 error = msleep(sc, &sc->sc_mtx, PRIBIO,
1963                                     "gj:work", hz * 3);
1964                                 if (error == 0) {
1965                                         mtx_unlock(&sc->sc_mtx);
1966                                         break;
1967                                 }
1968                                 GJ_DEBUG(3, "Report: current count=%d",
1969                                     sc->sc_current_count);
1970                                 GJ_DEBUG(3, "Report: flush count=%d",
1971                                     sc->sc_flush_count);
1972                                 GJ_DEBUG(3, "Report: flush in progress=%d",
1973                                     sc->sc_flush_in_progress);
1974                                 GJ_DEBUG(3, "Report: copy in progress=%d",
1975                                     sc->sc_copy_in_progress);
1976                                 GJ_DEBUG(3, "Report: delayed=%d",
1977                                     sc->sc_delayed_count);
1978                         }
1979                 }
1980                 GJ_DEBUG(3, "%s: exit 1", __func__);
1981                 return;
1982         }
1983
1984         /*
1985          * Flush even not full records every 3 seconds.
1986          */
1987         timeout = (last_write + 3 - time_second) * hz;
1988         if (timeout <= 0) {
1989                 mtx_unlock(&sc->sc_mtx);
1990                 g_journal_flush(sc);
1991                 g_journal_flush_send(sc);
1992                 GJ_DEBUG(3, "%s: exit 2", __func__);
1993                 return;
1994         }
1995         error = msleep(sc, &sc->sc_mtx, PRIBIO | PDROP, "gj:work", timeout);
1996         if (error == EWOULDBLOCK)
1997                 g_journal_flush_send(sc);
1998         GJ_DEBUG(3, "%s: exit 3", __func__);
1999 }
2000
2001 /*
2002  * Worker thread.
2003  */
2004 static void
2005 g_journal_worker(void *arg)
2006 {
2007         struct g_journal_softc *sc;
2008         struct g_geom *gp;
2009         struct g_provider *pp;
2010         struct bio *bp;
2011         time_t last_write;
2012         int type;
2013
2014         thread_lock(curthread);
2015         sched_prio(curthread, PRIBIO);
2016         thread_unlock(curthread);
2017
2018         sc = arg;
2019         type = 0;       /* gcc */
2020
2021         if (sc->sc_flags & GJF_DEVICE_CLEAN) {
2022                 GJ_DEBUG(0, "Journal %s clean.", sc->sc_name);
2023                 g_journal_initialize(sc);
2024         } else {
2025                 g_journal_sync(sc);
2026         }
2027         /*
2028          * Check if we can use BIO_FLUSH.
2029          */
2030         sc->sc_bio_flush = 0;
2031         if (g_io_flush(sc->sc_jconsumer) == 0) {
2032                 sc->sc_bio_flush |= GJ_FLUSH_JOURNAL;
2033                 GJ_DEBUG(1, "BIO_FLUSH supported by %s.",
2034                     sc->sc_jconsumer->provider->name);
2035         } else {
2036                 GJ_DEBUG(0, "BIO_FLUSH not supported by %s.",
2037                     sc->sc_jconsumer->provider->name);
2038         }
2039         if (sc->sc_jconsumer != sc->sc_dconsumer) {
2040                 if (g_io_flush(sc->sc_dconsumer) == 0) {
2041                         sc->sc_bio_flush |= GJ_FLUSH_DATA;
2042                         GJ_DEBUG(1, "BIO_FLUSH supported by %s.",
2043                             sc->sc_dconsumer->provider->name);
2044                 } else {
2045                         GJ_DEBUG(0, "BIO_FLUSH not supported by %s.",
2046                             sc->sc_dconsumer->provider->name);
2047                 }
2048         }
2049
2050         gp = sc->sc_geom;
2051         g_topology_lock();
2052         pp = g_new_providerf(gp, "%s.journal", sc->sc_name);
2053         pp->mediasize = sc->sc_mediasize;
2054         /*
2055          * There could be a problem when data provider and journal providers
2056          * have different sectorsize, but such scenario is prevented on journal
2057          * creation.
2058          */
2059         pp->sectorsize = sc->sc_sectorsize;
2060         g_error_provider(pp, 0);
2061         g_topology_unlock();
2062         last_write = time_second;
2063
2064         if (sc->sc_rootmount != NULL) {
2065                 GJ_DEBUG(1, "root_mount_rel %p", sc->sc_rootmount);
2066                 root_mount_rel(sc->sc_rootmount);
2067                 sc->sc_rootmount = NULL;
2068         }
2069
2070         for (;;) {
2071                 /* Get first request from the queue. */
2072                 mtx_lock(&sc->sc_mtx);
2073                 bp = bioq_first(&sc->sc_back_queue);
2074                 if (bp != NULL)
2075                         type = (bp->bio_cflags & GJ_BIO_MASK);
2076                 if (bp == NULL) {
2077                         bp = bioq_first(&sc->sc_regular_queue);
2078                         if (bp != NULL)
2079                                 type = GJ_BIO_REGULAR;
2080                 }
2081                 if (bp == NULL) {
2082 try_switch:
2083                         if ((sc->sc_flags & GJF_DEVICE_SWITCH) ||
2084                             (sc->sc_flags & GJF_DEVICE_DESTROY)) {
2085                                 if (sc->sc_current_count > 0) {
2086                                         mtx_unlock(&sc->sc_mtx);
2087                                         g_journal_flush(sc);
2088                                         g_journal_flush_send(sc);
2089                                         continue;
2090                                 }
2091                                 if (sc->sc_flush_in_progress > 0)
2092                                         goto sleep;
2093                                 if (sc->sc_copy_in_progress > 0)
2094                                         goto sleep;
2095                         }
2096                         if (sc->sc_flags & GJF_DEVICE_SWITCH) {
2097                                 mtx_unlock(&sc->sc_mtx);
2098                                 g_journal_switch(sc);
2099                                 wakeup(&sc->sc_journal_copying);
2100                                 continue;
2101                         }
2102                         if (sc->sc_flags & GJF_DEVICE_DESTROY) {
2103                                 GJ_DEBUG(1, "Shutting down worker "
2104                                     "thread for %s.", gp->name);
2105                                 sc->sc_worker = NULL;
2106                                 wakeup(&sc->sc_worker);
2107                                 mtx_unlock(&sc->sc_mtx);
2108                                 kproc_exit(0);
2109                         }
2110 sleep:
2111                         g_journal_wait(sc, last_write);
2112                         continue;
2113                 }
2114                 /*
2115                  * If we're in switch process, we need to delay all new
2116                  * write requests until its done.
2117                  */
2118                 if ((sc->sc_flags & GJF_DEVICE_SWITCH) &&
2119                     type == GJ_BIO_REGULAR && bp->bio_cmd == BIO_WRITE) {
2120                         GJ_LOGREQ(2, bp, "WRITE on SWITCH");
2121                         goto try_switch;
2122                 }
2123                 if (type == GJ_BIO_REGULAR)
2124                         bioq_remove(&sc->sc_regular_queue, bp);
2125                 else
2126                         bioq_remove(&sc->sc_back_queue, bp);
2127                 mtx_unlock(&sc->sc_mtx);
2128                 switch (type) {
2129                 case GJ_BIO_REGULAR:
2130                         /* Regular request. */
2131                         switch (bp->bio_cmd) {
2132                         case BIO_READ:
2133                                 g_journal_read(sc, bp, bp->bio_offset,
2134                                     bp->bio_offset + bp->bio_length);
2135                                 break;
2136                         case BIO_WRITE:
2137                                 last_write = time_second;
2138                                 g_journal_add_request(sc, bp);
2139                                 g_journal_flush_send(sc);
2140                                 break;
2141                         default:
2142                                 panic("Invalid bio_cmd (%d).", bp->bio_cmd);
2143                         }
2144                         break;
2145                 case GJ_BIO_COPY:
2146                         switch (bp->bio_cmd) {
2147                         case BIO_READ:
2148                                 if (g_journal_copy_read_done(bp))
2149                                         g_journal_copy_send(sc);
2150                                 break;
2151                         case BIO_WRITE:
2152                                 g_journal_copy_write_done(bp);
2153                                 g_journal_copy_send(sc);
2154                                 break;
2155                         default:
2156                                 panic("Invalid bio_cmd (%d).", bp->bio_cmd);
2157                         }
2158                         break;
2159                 case GJ_BIO_JOURNAL:
2160                         g_journal_flush_done(bp);
2161                         g_journal_flush_send(sc);
2162                         break;
2163                 case GJ_BIO_READ:
2164                 default:
2165                         panic("Invalid bio (%d).", type);
2166                 }
2167         }
2168 }
2169
2170 static void
2171 g_journal_destroy_event(void *arg, int flags __unused)
2172 {
2173         struct g_journal_softc *sc;
2174
2175         g_topology_assert();
2176         sc = arg;
2177         g_journal_destroy(sc);
2178 }
2179
2180 static void
2181 g_journal_timeout(void *arg)
2182 {
2183         struct g_journal_softc *sc;
2184
2185         sc = arg;
2186         GJ_DEBUG(0, "Timeout. Journal %s cannot be completed.",
2187             sc->sc_geom->name);
2188         g_post_event(g_journal_destroy_event, sc, M_NOWAIT, NULL);
2189 }
2190
2191 static struct g_geom *
2192 g_journal_create(struct g_class *mp, struct g_provider *pp,
2193     const struct g_journal_metadata *md)
2194 {
2195         struct g_journal_softc *sc;
2196         struct g_geom *gp;
2197         struct g_consumer *cp;
2198         int error;
2199
2200         sc = NULL;      /* gcc */
2201
2202         g_topology_assert();
2203         /*
2204          * There are two possibilities:
2205          * 1. Data and both journals are on the same provider.
2206          * 2. Data and journals are all on separated providers.
2207          */
2208         /* Look for journal device with the same ID. */
2209         LIST_FOREACH(gp, &mp->geom, geom) {
2210                 sc = gp->softc;
2211                 if (sc == NULL)
2212                         continue;
2213                 if (sc->sc_id == md->md_id)
2214                         break;
2215         }
2216         if (gp == NULL)
2217                 sc = NULL;
2218         else if (sc != NULL && (sc->sc_type & md->md_type) != 0) {
2219                 GJ_DEBUG(1, "Journal device %u already configured.", sc->sc_id);
2220                 return (NULL);
2221         }
2222         if (md->md_type == 0 || (md->md_type & ~GJ_TYPE_COMPLETE) != 0) {
2223                 GJ_DEBUG(0, "Invalid type on %s.", pp->name);
2224                 return (NULL);
2225         }
2226         if (md->md_type & GJ_TYPE_DATA) {
2227                 GJ_DEBUG(0, "Journal %u: %s contains data.", md->md_id,
2228                     pp->name);
2229         }
2230         if (md->md_type & GJ_TYPE_JOURNAL) {
2231                 GJ_DEBUG(0, "Journal %u: %s contains journal.", md->md_id,
2232                     pp->name);
2233         }
2234
2235         if (sc == NULL) {
2236                 /* Action geom. */
2237                 sc = malloc(sizeof(*sc), M_JOURNAL, M_WAITOK | M_ZERO);
2238                 sc->sc_id = md->md_id;
2239                 sc->sc_type = 0;
2240                 sc->sc_flags = 0;
2241                 sc->sc_worker = NULL;
2242
2243                 gp = g_new_geomf(mp, "gjournal %u", sc->sc_id);
2244                 gp->start = g_journal_start;
2245                 gp->orphan = g_journal_orphan;
2246                 gp->access = g_journal_access;
2247                 gp->softc = sc;
2248                 gp->flags |= G_GEOM_VOLATILE_BIO;
2249                 sc->sc_geom = gp;
2250
2251                 mtx_init(&sc->sc_mtx, "gjournal", NULL, MTX_DEF);
2252
2253                 bioq_init(&sc->sc_back_queue);
2254                 bioq_init(&sc->sc_regular_queue);
2255                 bioq_init(&sc->sc_delayed_queue);
2256                 sc->sc_delayed_count = 0;
2257                 sc->sc_current_queue = NULL;
2258                 sc->sc_current_count = 0;
2259                 sc->sc_flush_queue = NULL;
2260                 sc->sc_flush_count = 0;
2261                 sc->sc_flush_in_progress = 0;
2262                 sc->sc_copy_queue = NULL;
2263                 sc->sc_copy_in_progress = 0;
2264                 sc->sc_inactive.jj_queue = NULL;
2265                 sc->sc_active.jj_queue = NULL;
2266
2267                 sc->sc_rootmount = root_mount_hold("GJOURNAL");
2268                 GJ_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
2269
2270                 callout_init(&sc->sc_callout, 1);
2271                 if (md->md_type != GJ_TYPE_COMPLETE) {
2272                         /*
2273                          * Journal and data are on separate providers.
2274                          * At this point we have only one of them.
2275                          * We setup a timeout in case the other part will not
2276                          * appear, so we won't wait forever.
2277                          */
2278                         callout_reset(&sc->sc_callout, 5 * hz,
2279                             g_journal_timeout, sc);
2280                 }
2281         }
2282
2283         /* Remember type of the data provider. */
2284         if (md->md_type & GJ_TYPE_DATA)
2285                 sc->sc_orig_type = md->md_type;
2286         sc->sc_type |= md->md_type;
2287         cp = NULL;
2288
2289         if (md->md_type & GJ_TYPE_DATA) {
2290                 if (md->md_flags & GJ_FLAG_CLEAN)
2291                         sc->sc_flags |= GJF_DEVICE_CLEAN;
2292                 if (md->md_flags & GJ_FLAG_CHECKSUM)
2293                         sc->sc_flags |= GJF_DEVICE_CHECKSUM;
2294                 cp = g_new_consumer(gp);
2295                 error = g_attach(cp, pp);
2296                 KASSERT(error == 0, ("Cannot attach to %s (error=%d).",
2297                     pp->name, error));
2298                 error = g_access(cp, 1, 1, 1);
2299                 if (error != 0) {
2300                         GJ_DEBUG(0, "Cannot access %s (error=%d).", pp->name,
2301                             error);
2302                         g_journal_destroy(sc);
2303                         return (NULL);
2304                 }
2305                 sc->sc_dconsumer = cp;
2306                 sc->sc_mediasize = pp->mediasize - pp->sectorsize;
2307                 sc->sc_sectorsize = pp->sectorsize;
2308                 sc->sc_jstart = md->md_jstart;
2309                 sc->sc_jend = md->md_jend;
2310                 if (md->md_provider[0] != '\0')
2311                         sc->sc_flags |= GJF_DEVICE_HARDCODED;
2312                 sc->sc_journal_offset = md->md_joffset;
2313                 sc->sc_journal_id = md->md_jid;
2314                 sc->sc_journal_previous_id = md->md_jid;
2315         }
2316         if (md->md_type & GJ_TYPE_JOURNAL) {
2317                 if (cp == NULL) {
2318                         cp = g_new_consumer(gp);
2319                         error = g_attach(cp, pp);
2320                         KASSERT(error == 0, ("Cannot attach to %s (error=%d).",
2321                             pp->name, error));
2322                         error = g_access(cp, 1, 1, 1);
2323                         if (error != 0) {
2324                                 GJ_DEBUG(0, "Cannot access %s (error=%d).",
2325                                     pp->name, error);
2326                                 g_journal_destroy(sc);
2327                                 return (NULL);
2328                         }
2329                 } else {
2330                         /*
2331                          * Journal is on the same provider as data, which means
2332                          * that data provider ends where journal starts.
2333                          */
2334                         sc->sc_mediasize = md->md_jstart;
2335                 }
2336                 sc->sc_jconsumer = cp;
2337         }
2338
2339         /* Start switcher kproc if needed. */
2340         if (g_journal_switcher_proc == NULL)
2341                 g_journal_start_switcher(mp);
2342
2343         if ((sc->sc_type & GJ_TYPE_COMPLETE) != GJ_TYPE_COMPLETE) {
2344                 /* Journal is not complete yet. */
2345                 return (gp);
2346         } else {
2347                 /* Journal complete, cancel timeout. */
2348                 callout_drain(&sc->sc_callout);
2349         }
2350
2351         error = kproc_create(g_journal_worker, sc, &sc->sc_worker, 0, 0,
2352             "g_journal %s", sc->sc_name);
2353         if (error != 0) {
2354                 GJ_DEBUG(0, "Cannot create worker thread for %s.journal.",
2355                     sc->sc_name);
2356                 g_journal_destroy(sc);
2357                 return (NULL);
2358         }
2359
2360         return (gp);
2361 }
2362
2363 static void
2364 g_journal_destroy_consumer(void *arg, int flags __unused)
2365 {
2366         struct g_consumer *cp;
2367
2368         g_topology_assert();
2369         cp = arg;
2370         g_detach(cp);
2371         g_destroy_consumer(cp);
2372 }
2373
2374 static int
2375 g_journal_destroy(struct g_journal_softc *sc)
2376 {
2377         struct g_geom *gp;
2378         struct g_provider *pp;
2379         struct g_consumer *cp;
2380
2381         g_topology_assert();
2382
2383         if (sc == NULL)
2384                 return (ENXIO);
2385
2386         gp = sc->sc_geom;
2387         pp = LIST_FIRST(&gp->provider);
2388         if (pp != NULL) {
2389                 if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0) {
2390                         GJ_DEBUG(1, "Device %s is still open (r%dw%de%d).",
2391                             pp->name, pp->acr, pp->acw, pp->ace);
2392                         return (EBUSY);
2393                 }
2394                 g_error_provider(pp, ENXIO);
2395
2396                 g_journal_flush(sc);
2397                 g_journal_flush_send(sc);
2398                 g_journal_switch(sc);
2399         }
2400
2401         sc->sc_flags |= (GJF_DEVICE_DESTROY | GJF_DEVICE_CLEAN);
2402
2403         g_topology_unlock();
2404
2405         if (sc->sc_rootmount != NULL) {
2406                 GJ_DEBUG(1, "root_mount_rel %p", sc->sc_rootmount);
2407                 root_mount_rel(sc->sc_rootmount);
2408                 sc->sc_rootmount = NULL;
2409         }
2410
2411         callout_drain(&sc->sc_callout);
2412         mtx_lock(&sc->sc_mtx);
2413         wakeup(sc);
2414         while (sc->sc_worker != NULL)
2415                 msleep(&sc->sc_worker, &sc->sc_mtx, PRIBIO, "gj:destroy", 0);
2416         mtx_unlock(&sc->sc_mtx);
2417
2418         if (pp != NULL) {
2419                 GJ_DEBUG(1, "Marking %s as clean.", sc->sc_name);
2420                 g_journal_metadata_update(sc);
2421                 g_topology_lock();
2422                 g_wither_provider(pp, ENXIO);
2423         } else {
2424                 g_topology_lock();
2425         }
2426         mtx_destroy(&sc->sc_mtx);
2427
2428         if (sc->sc_current_count != 0) {
2429                 GJ_DEBUG(0, "Warning! Number of current requests %d.",
2430                     sc->sc_current_count);
2431         }
2432
2433         gp->softc = NULL;
2434         LIST_FOREACH(cp, &gp->consumer, consumer) {
2435                 if (cp->acr + cp->acw + cp->ace > 0)
2436                         g_access(cp, -1, -1, -1);
2437                 /*
2438                  * We keep all consumers open for writting, so if I'll detach
2439                  * and destroy consumer here, I'll get providers for taste, so
2440                  * journal will be started again.
2441                  * Sending an event here, prevents this from happening.
2442                  */
2443                 g_post_event(g_journal_destroy_consumer, cp, M_WAITOK, NULL);
2444         }
2445         g_wither_geom(gp, ENXIO);
2446         free(sc, M_JOURNAL);
2447         return (0);
2448 }
2449
2450 static void
2451 g_journal_taste_orphan(struct g_consumer *cp)
2452 {
2453
2454         KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
2455             cp->provider->name));
2456 }
2457
2458 static struct g_geom *
2459 g_journal_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
2460 {
2461         struct g_journal_metadata md;
2462         struct g_consumer *cp;
2463         struct g_geom *gp;
2464         int error;
2465
2466         g_topology_assert();
2467         g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
2468         GJ_DEBUG(2, "Tasting %s.", pp->name);
2469         if (pp->geom->class == mp)
2470                 return (NULL);
2471
2472         gp = g_new_geomf(mp, "journal:taste");
2473         /* This orphan function should be never called. */
2474         gp->orphan = g_journal_taste_orphan;
2475         cp = g_new_consumer(gp);
2476         g_attach(cp, pp);
2477         error = g_journal_metadata_read(cp, &md);
2478         g_detach(cp);
2479         g_destroy_consumer(cp);
2480         g_destroy_geom(gp);
2481         if (error != 0)
2482                 return (NULL);
2483         gp = NULL;
2484
2485         if (md.md_provider[0] != '\0' &&
2486             !g_compare_names(md.md_provider, pp->name))
2487                 return (NULL);
2488         if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
2489                 return (NULL);
2490         if (g_journal_debug >= 2)
2491                 journal_metadata_dump(&md);
2492
2493         gp = g_journal_create(mp, pp, &md);
2494         return (gp);
2495 }
2496
2497 static struct g_journal_softc *
2498 g_journal_find_device(struct g_class *mp, const char *name)
2499 {
2500         struct g_journal_softc *sc;
2501         struct g_geom *gp;
2502         struct g_provider *pp;
2503
2504         if (strncmp(name, "/dev/", 5) == 0)
2505                 name += 5;
2506         LIST_FOREACH(gp, &mp->geom, geom) {
2507                 sc = gp->softc;
2508                 if (sc == NULL)
2509                         continue;
2510                 if (sc->sc_flags & GJF_DEVICE_DESTROY)
2511                         continue;
2512                 if ((sc->sc_type & GJ_TYPE_COMPLETE) != GJ_TYPE_COMPLETE)
2513                         continue;
2514                 pp = LIST_FIRST(&gp->provider);
2515                 if (strcmp(sc->sc_name, name) == 0)
2516                         return (sc);
2517                 if (pp != NULL && strcmp(pp->name, name) == 0)
2518                         return (sc);
2519         }
2520         return (NULL);
2521 }
2522
2523 static void
2524 g_journal_ctl_destroy(struct gctl_req *req, struct g_class *mp)
2525 {
2526         struct g_journal_softc *sc;
2527         const char *name;
2528         char param[16];
2529         int *nargs;
2530         int error, i;
2531
2532         g_topology_assert();
2533
2534         nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
2535         if (nargs == NULL) {
2536                 gctl_error(req, "No '%s' argument.", "nargs");
2537                 return;
2538         }
2539         if (*nargs <= 0) {
2540                 gctl_error(req, "Missing device(s).");
2541                 return;
2542         }
2543
2544         for (i = 0; i < *nargs; i++) {
2545                 snprintf(param, sizeof(param), "arg%d", i);
2546                 name = gctl_get_asciiparam(req, param);
2547                 if (name == NULL) {
2548                         gctl_error(req, "No 'arg%d' argument.", i);
2549                         return;
2550                 }
2551                 sc = g_journal_find_device(mp, name);
2552                 if (sc == NULL) {
2553                         gctl_error(req, "No such device: %s.", name);
2554                         return;
2555                 }
2556                 error = g_journal_destroy(sc);
2557                 if (error != 0) {
2558                         gctl_error(req, "Cannot destroy device %s (error=%d).",
2559                             LIST_FIRST(&sc->sc_geom->provider)->name, error);
2560                         return;
2561                 }
2562         }
2563 }
2564
2565 static void
2566 g_journal_ctl_sync(struct gctl_req *req __unused, struct g_class *mp __unused)
2567 {
2568
2569         g_topology_assert();
2570         g_topology_unlock();
2571         g_journal_sync_requested++;
2572         wakeup(&g_journal_switcher_state);
2573         while (g_journal_sync_requested > 0)
2574                 tsleep(&g_journal_sync_requested, PRIBIO, "j:sreq", hz / 2);
2575         g_topology_lock();
2576 }
2577
2578 static void
2579 g_journal_config(struct gctl_req *req, struct g_class *mp, const char *verb)
2580 {
2581         uint32_t *version;
2582
2583         g_topology_assert();
2584
2585         version = gctl_get_paraml(req, "version", sizeof(*version));
2586         if (version == NULL) {
2587                 gctl_error(req, "No '%s' argument.", "version");
2588                 return;
2589         }
2590         if (*version != G_JOURNAL_VERSION) {
2591                 gctl_error(req, "Userland and kernel parts are out of sync.");
2592                 return;
2593         }
2594
2595         if (strcmp(verb, "destroy") == 0 || strcmp(verb, "stop") == 0) {
2596                 g_journal_ctl_destroy(req, mp);
2597                 return;
2598         } else if (strcmp(verb, "sync") == 0) {
2599                 g_journal_ctl_sync(req, mp);
2600                 return;
2601         }
2602
2603         gctl_error(req, "Unknown verb.");
2604 }
2605
2606 static void
2607 g_journal_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
2608     struct g_consumer *cp, struct g_provider *pp)
2609 {
2610         struct g_journal_softc *sc;
2611
2612         g_topology_assert();
2613
2614         sc = gp->softc;
2615         if (sc == NULL)
2616                 return;
2617         if (pp != NULL) {
2618                 /* Nothing here. */
2619         } else if (cp != NULL) {
2620                 int first = 1;
2621
2622                 sbuf_printf(sb, "%s<Role>", indent);
2623                 if (cp == sc->sc_dconsumer) {
2624                         sbuf_printf(sb, "Data");
2625                         first = 0;
2626                 }
2627                 if (cp == sc->sc_jconsumer) {
2628                         if (!first)
2629                                 sbuf_printf(sb, ",");
2630                         sbuf_printf(sb, "Journal");
2631                 }
2632                 sbuf_printf(sb, "</Role>\n");
2633                 if (cp == sc->sc_jconsumer) {
2634                         sbuf_printf(sb, "<Jstart>%jd</Jstart>\n",
2635                             (intmax_t)sc->sc_jstart);
2636                         sbuf_printf(sb, "<Jend>%jd</Jend>\n",
2637                             (intmax_t)sc->sc_jend);
2638                 }
2639         } else {
2640                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
2641         }
2642 }
2643
2644 static eventhandler_tag g_journal_event_shutdown = NULL;
2645 static eventhandler_tag g_journal_event_lowmem = NULL;
2646
2647 static void
2648 g_journal_shutdown(void *arg, int howto __unused)
2649 {
2650         struct g_class *mp;
2651         struct g_geom *gp, *gp2;
2652
2653         if (panicstr != NULL)
2654                 return;
2655         mp = arg;
2656         g_topology_lock();
2657         LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
2658                 if (gp->softc == NULL)
2659                         continue;
2660                 GJ_DEBUG(0, "Shutting down geom %s.", gp->name);
2661                 g_journal_destroy(gp->softc);
2662         }
2663         g_topology_unlock();
2664 }
2665
2666 /*
2667  * Free cached requests from inactive queue in case of low memory.
2668  * We free GJ_FREE_AT_ONCE elements at once.
2669  */
2670 #define GJ_FREE_AT_ONCE 4
2671 static void
2672 g_journal_lowmem(void *arg, int howto __unused)
2673 {
2674         struct g_journal_softc *sc;
2675         struct g_class *mp;
2676         struct g_geom *gp;
2677         struct bio *bp;
2678         u_int nfree = GJ_FREE_AT_ONCE;
2679
2680         g_journal_stats_low_mem++;
2681         mp = arg;
2682         g_topology_lock();
2683         LIST_FOREACH(gp, &mp->geom, geom) {
2684                 sc = gp->softc;
2685                 if (sc == NULL || (sc->sc_flags & GJF_DEVICE_DESTROY))
2686                         continue;
2687                 mtx_lock(&sc->sc_mtx);
2688                 for (bp = sc->sc_inactive.jj_queue; nfree > 0 && bp != NULL;
2689                     nfree--, bp = bp->bio_next) {
2690                         /*
2691                          * This is safe to free the bio_data, because:
2692                          * 1. If bio_data is NULL it will be read from the
2693                          *    inactive journal.
2694                          * 2. If bp is sent down, it is first removed from the
2695                          *    inactive queue, so it's impossible to free the
2696                          *    data from under in-flight bio.
2697                          * On the other hand, freeing elements from the active
2698                          * queue, is not safe.
2699                          */
2700                         if (bp->bio_data != NULL) {
2701                                 GJ_DEBUG(2, "Freeing data from %s.",
2702                                     sc->sc_name);
2703                                 gj_free(bp->bio_data, bp->bio_length);
2704                                 bp->bio_data = NULL;
2705                         }
2706                 }
2707                 mtx_unlock(&sc->sc_mtx);
2708                 if (nfree == 0)
2709                         break;
2710         }
2711         g_topology_unlock();
2712 }
2713
2714 static void g_journal_switcher(void *arg);
2715
2716 static void
2717 g_journal_init(struct g_class *mp)
2718 {
2719
2720         /* Pick a conservative value if provided value sucks. */
2721         if (g_journal_cache_divisor <= 0 ||
2722             (vm_kmem_size / g_journal_cache_divisor == 0)) {
2723                 g_journal_cache_divisor = 5;
2724         }
2725         if (g_journal_cache_limit > 0) {
2726                 g_journal_cache_limit = vm_kmem_size / g_journal_cache_divisor;
2727                 g_journal_cache_low =
2728                     (g_journal_cache_limit / 100) * g_journal_cache_switch;
2729         }
2730         g_journal_event_shutdown = EVENTHANDLER_REGISTER(shutdown_post_sync,
2731             g_journal_shutdown, mp, EVENTHANDLER_PRI_FIRST);
2732         if (g_journal_event_shutdown == NULL)
2733                 GJ_DEBUG(0, "Warning! Cannot register shutdown event.");
2734         g_journal_event_lowmem = EVENTHANDLER_REGISTER(vm_lowmem,
2735             g_journal_lowmem, mp, EVENTHANDLER_PRI_FIRST);
2736         if (g_journal_event_lowmem == NULL)
2737                 GJ_DEBUG(0, "Warning! Cannot register lowmem event.");
2738 }
2739
2740 static void
2741 g_journal_fini(struct g_class *mp)
2742 {
2743
2744         if (g_journal_event_shutdown != NULL) {
2745                 EVENTHANDLER_DEREGISTER(shutdown_post_sync,
2746                     g_journal_event_shutdown);
2747         }
2748         if (g_journal_event_lowmem != NULL)
2749                 EVENTHANDLER_DEREGISTER(vm_lowmem, g_journal_event_lowmem);
2750         g_journal_stop_switcher();
2751 }
2752
2753 DECLARE_GEOM_CLASS(g_journal_class, g_journal);
2754
2755 static const struct g_journal_desc *
2756 g_journal_find_desc(const char *fstype)
2757 {
2758         const struct g_journal_desc *desc;
2759         int i;
2760
2761         for (desc = g_journal_filesystems[i = 0]; desc != NULL;
2762              desc = g_journal_filesystems[++i]) {
2763                 if (strcmp(desc->jd_fstype, fstype) == 0)
2764                         break;
2765         }
2766         return (desc);
2767 }
2768
2769 static void
2770 g_journal_switch_wait(struct g_journal_softc *sc)
2771 {
2772         struct bintime bt;
2773
2774         mtx_assert(&sc->sc_mtx, MA_OWNED);
2775         if (g_journal_debug >= 2) {
2776                 if (sc->sc_flush_in_progress > 0) {
2777                         GJ_DEBUG(2, "%d requests flushing.",
2778                             sc->sc_flush_in_progress);
2779                 }
2780                 if (sc->sc_copy_in_progress > 0) {
2781                         GJ_DEBUG(2, "%d requests copying.",
2782                             sc->sc_copy_in_progress);
2783                 }
2784                 if (sc->sc_flush_count > 0) {
2785                         GJ_DEBUG(2, "%d requests to flush.",
2786                             sc->sc_flush_count);
2787                 }
2788                 if (sc->sc_delayed_count > 0) {
2789                         GJ_DEBUG(2, "%d requests delayed.",
2790                             sc->sc_delayed_count);
2791                 }
2792         }
2793         g_journal_stats_switches++;
2794         if (sc->sc_copy_in_progress > 0)
2795                 g_journal_stats_wait_for_copy++;
2796         GJ_TIMER_START(1, &bt);
2797         sc->sc_flags &= ~GJF_DEVICE_BEFORE_SWITCH;
2798         sc->sc_flags |= GJF_DEVICE_SWITCH;
2799         wakeup(sc);
2800         while (sc->sc_flags & GJF_DEVICE_SWITCH) {
2801                 msleep(&sc->sc_journal_copying, &sc->sc_mtx, PRIBIO,
2802                     "gj:switch", 0);
2803         }
2804         GJ_TIMER_STOP(1, &bt, "Switch time of %s", sc->sc_name);
2805 }
2806
2807 static void
2808 g_journal_do_switch(struct g_class *classp)
2809 {
2810         struct g_journal_softc *sc;
2811         const struct g_journal_desc *desc;
2812         struct g_geom *gp;
2813         struct mount *mp;
2814         struct bintime bt;
2815         char *mountpoint;
2816         int error, save;
2817
2818         g_topology_lock();
2819         LIST_FOREACH(gp, &classp->geom, geom) {
2820                 sc = gp->softc;
2821                 if (sc == NULL)
2822                         continue;
2823                 if (sc->sc_flags & GJF_DEVICE_DESTROY)
2824                         continue;
2825                 if ((sc->sc_type & GJ_TYPE_COMPLETE) != GJ_TYPE_COMPLETE)
2826                         continue;
2827                 mtx_lock(&sc->sc_mtx);
2828                 sc->sc_flags |= GJF_DEVICE_BEFORE_SWITCH;
2829                 mtx_unlock(&sc->sc_mtx);
2830         }
2831         g_topology_unlock();
2832
2833         mtx_lock(&mountlist_mtx);
2834         TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2835                 if (mp->mnt_gjprovider == NULL)
2836                         continue;
2837                 if (mp->mnt_flag & MNT_RDONLY)
2838                         continue;
2839                 desc = g_journal_find_desc(mp->mnt_stat.f_fstypename);
2840                 if (desc == NULL)
2841                         continue;
2842                 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK))
2843                         continue;
2844                 /* mtx_unlock(&mountlist_mtx) was done inside vfs_busy() */
2845
2846                 g_topology_lock();
2847                 sc = g_journal_find_device(classp, mp->mnt_gjprovider);
2848                 g_topology_unlock();
2849
2850                 if (sc == NULL) {
2851                         GJ_DEBUG(0, "Cannot find journal geom for %s.",
2852                             mp->mnt_gjprovider);
2853                         goto next;
2854                 } else if (JEMPTY(sc)) {
2855                         mtx_lock(&sc->sc_mtx);
2856                         sc->sc_flags &= ~GJF_DEVICE_BEFORE_SWITCH;
2857                         mtx_unlock(&sc->sc_mtx);
2858                         GJ_DEBUG(3, "No need for %s switch.", sc->sc_name);
2859                         goto next;
2860                 }
2861
2862                 mountpoint = mp->mnt_stat.f_mntonname;
2863
2864                 error = vn_start_write(NULL, &mp, V_WAIT);
2865                 if (error != 0) {
2866                         GJ_DEBUG(0, "vn_start_write(%s) failed (error=%d).",
2867                             mountpoint, error);
2868                         goto next;
2869                 }
2870
2871                 save = curthread_pflags_set(TDP_SYNCIO);
2872
2873                 GJ_TIMER_START(1, &bt);
2874                 vfs_msync(mp, MNT_NOWAIT);
2875                 GJ_TIMER_STOP(1, &bt, "Msync time of %s", mountpoint);
2876
2877                 GJ_TIMER_START(1, &bt);
2878                 error = VFS_SYNC(mp, MNT_NOWAIT);
2879                 if (error == 0)
2880                         GJ_TIMER_STOP(1, &bt, "Sync time of %s", mountpoint);
2881                 else {
2882                         GJ_DEBUG(0, "Cannot sync file system %s (error=%d).",
2883                             mountpoint, error);
2884                 }
2885
2886                 curthread_pflags_restore(save);
2887
2888                 vn_finished_write(mp);
2889
2890                 if (error != 0)
2891                         goto next;
2892
2893                 /*
2894                  * Send BIO_FLUSH before freezing the file system, so it can be
2895                  * faster after the freeze.
2896                  */
2897                 GJ_TIMER_START(1, &bt);
2898                 g_journal_flush_cache(sc);
2899                 GJ_TIMER_STOP(1, &bt, "BIO_FLUSH time of %s", sc->sc_name);
2900
2901                 GJ_TIMER_START(1, &bt);
2902                 error = vfs_write_suspend(mp, VS_SKIP_UNMOUNT);
2903                 GJ_TIMER_STOP(1, &bt, "Suspend time of %s", mountpoint);
2904                 if (error != 0) {
2905                         GJ_DEBUG(0, "Cannot suspend file system %s (error=%d).",
2906                             mountpoint, error);
2907                         goto next;
2908                 }
2909
2910                 error = desc->jd_clean(mp);
2911                 if (error != 0)
2912                         goto next;
2913
2914                 mtx_lock(&sc->sc_mtx);
2915                 g_journal_switch_wait(sc);
2916                 mtx_unlock(&sc->sc_mtx);
2917
2918                 vfs_write_resume(mp, 0);
2919 next:
2920                 mtx_lock(&mountlist_mtx);
2921                 vfs_unbusy(mp);
2922         }
2923         mtx_unlock(&mountlist_mtx);
2924
2925         sc = NULL;
2926         for (;;) {
2927                 g_topology_lock();
2928                 LIST_FOREACH(gp, &g_journal_class.geom, geom) {
2929                         sc = gp->softc;
2930                         if (sc == NULL)
2931                                 continue;
2932                         mtx_lock(&sc->sc_mtx);
2933                         if ((sc->sc_type & GJ_TYPE_COMPLETE) == GJ_TYPE_COMPLETE &&
2934                             !(sc->sc_flags & GJF_DEVICE_DESTROY) &&
2935                             (sc->sc_flags & GJF_DEVICE_BEFORE_SWITCH)) {
2936                                 break;
2937                         }
2938                         mtx_unlock(&sc->sc_mtx);
2939                         sc = NULL;
2940                 }
2941                 g_topology_unlock();
2942                 if (sc == NULL)
2943                         break;
2944                 mtx_assert(&sc->sc_mtx, MA_OWNED);
2945                 g_journal_switch_wait(sc);
2946                 mtx_unlock(&sc->sc_mtx);
2947         }
2948 }
2949
2950 static void
2951 g_journal_start_switcher(struct g_class *mp)
2952 {
2953         int error;
2954
2955         g_topology_assert();
2956         MPASS(g_journal_switcher_proc == NULL);
2957         g_journal_switcher_state = GJ_SWITCHER_WORKING;
2958         error = kproc_create(g_journal_switcher, mp, &g_journal_switcher_proc,
2959             0, 0, "g_journal switcher");
2960         KASSERT(error == 0, ("Cannot create switcher thread."));
2961 }
2962
2963 static void
2964 g_journal_stop_switcher(void)
2965 {
2966         g_topology_assert();
2967         MPASS(g_journal_switcher_proc != NULL);
2968         g_journal_switcher_state = GJ_SWITCHER_DIE;
2969         wakeup(&g_journal_switcher_state);
2970         while (g_journal_switcher_state != GJ_SWITCHER_DIED)
2971                 tsleep(&g_journal_switcher_state, PRIBIO, "jfini:wait", hz / 5);
2972         GJ_DEBUG(1, "Switcher died.");
2973         g_journal_switcher_proc = NULL;
2974 }
2975
2976 /*
2977  * TODO: Kill switcher thread on last geom destruction?
2978  */
2979 static void
2980 g_journal_switcher(void *arg)
2981 {
2982         struct g_class *mp;
2983         struct bintime bt;
2984         int error;
2985
2986         mp = arg;
2987         curthread->td_pflags |= TDP_NORUNNINGBUF;
2988         for (;;) {
2989                 g_journal_switcher_wokenup = 0;
2990                 error = tsleep(&g_journal_switcher_state, PRIBIO, "jsw:wait",
2991                     g_journal_switch_time * hz);
2992                 if (g_journal_switcher_state == GJ_SWITCHER_DIE) {
2993                         g_journal_switcher_state = GJ_SWITCHER_DIED;
2994                         GJ_DEBUG(1, "Switcher exiting.");
2995                         wakeup(&g_journal_switcher_state);
2996                         kproc_exit(0);
2997                 }
2998                 if (error == 0 && g_journal_sync_requested == 0) {
2999                         GJ_DEBUG(1, "Out of cache, force switch (used=%jd "
3000                             "limit=%jd).", (intmax_t)g_journal_cache_used,
3001                             (intmax_t)g_journal_cache_limit);
3002                 }
3003                 GJ_TIMER_START(1, &bt);
3004                 g_journal_do_switch(mp);
3005                 GJ_TIMER_STOP(1, &bt, "Entire switch time");
3006                 if (g_journal_sync_requested > 0) {
3007                         g_journal_sync_requested = 0;
3008                         wakeup(&g_journal_sync_requested);
3009                 }
3010         }
3011 }