The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/geom/journal/g_journal.c

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    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 }

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