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

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    1 /*-
    2  * Copyright (c) 2006 Ruslan Ermilov <ru@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 AUTHOR 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 AUTHOR 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: releng/10.1/sys/geom/cache/g_cache.c 243333 2012-11-20 12:32:18Z jh $");
   29 
   30 #include <sys/param.h>
   31 #include <sys/systm.h>
   32 #include <sys/kernel.h>
   33 #include <sys/module.h>
   34 #include <sys/lock.h>
   35 #include <sys/mutex.h>
   36 #include <sys/bio.h>
   37 #include <sys/sysctl.h>
   38 #include <sys/malloc.h>
   39 #include <sys/queue.h>
   40 #include <sys/sbuf.h>
   41 #include <sys/time.h>
   42 #include <vm/uma.h>
   43 #include <geom/geom.h>
   44 #include <geom/cache/g_cache.h>
   45 
   46 FEATURE(geom_cache, "GEOM cache module");
   47 
   48 static MALLOC_DEFINE(M_GCACHE, "gcache_data", "GEOM_CACHE Data");
   49 
   50 SYSCTL_DECL(_kern_geom);
   51 static SYSCTL_NODE(_kern_geom, OID_AUTO, cache, CTLFLAG_RW, 0,
   52     "GEOM_CACHE stuff");
   53 static u_int g_cache_debug = 0;
   54 SYSCTL_UINT(_kern_geom_cache, OID_AUTO, debug, CTLFLAG_RW, &g_cache_debug, 0,
   55     "Debug level");
   56 static u_int g_cache_enable = 1;
   57 SYSCTL_UINT(_kern_geom_cache, OID_AUTO, enable, CTLFLAG_RW, &g_cache_enable, 0,
   58     "");
   59 static u_int g_cache_timeout = 10;
   60 SYSCTL_UINT(_kern_geom_cache, OID_AUTO, timeout, CTLFLAG_RW, &g_cache_timeout,
   61     0, "");
   62 static u_int g_cache_idletime = 5;
   63 SYSCTL_UINT(_kern_geom_cache, OID_AUTO, idletime, CTLFLAG_RW, &g_cache_idletime,
   64     0, "");
   65 static u_int g_cache_used_lo = 5;
   66 static u_int g_cache_used_hi = 20;
   67 static int
   68 sysctl_handle_pct(SYSCTL_HANDLER_ARGS)
   69 {
   70         u_int val = *(u_int *)arg1;
   71         int error;
   72 
   73         error = sysctl_handle_int(oidp, &val, 0, req);
   74         if (error || !req->newptr)
   75                 return (error);
   76         if (val < 0 || val > 100)
   77                 return (EINVAL);
   78         if ((arg1 == &g_cache_used_lo && val > g_cache_used_hi) ||
   79             (arg1 == &g_cache_used_hi && g_cache_used_lo > val))
   80                 return (EINVAL);
   81         *(u_int *)arg1 = val;
   82         return (0);
   83 }
   84 SYSCTL_PROC(_kern_geom_cache, OID_AUTO, used_lo, CTLTYPE_UINT|CTLFLAG_RW,
   85         &g_cache_used_lo, 0, sysctl_handle_pct, "IU", "");
   86 SYSCTL_PROC(_kern_geom_cache, OID_AUTO, used_hi, CTLTYPE_UINT|CTLFLAG_RW,
   87         &g_cache_used_hi, 0, sysctl_handle_pct, "IU", "");
   88 
   89 
   90 static int g_cache_destroy(struct g_cache_softc *sc, boolean_t force);
   91 static g_ctl_destroy_geom_t g_cache_destroy_geom;
   92 
   93 static g_taste_t g_cache_taste;
   94 static g_ctl_req_t g_cache_config;
   95 static g_dumpconf_t g_cache_dumpconf;
   96 
   97 struct g_class g_cache_class = {
   98         .name = G_CACHE_CLASS_NAME,
   99         .version = G_VERSION,
  100         .ctlreq = g_cache_config,
  101         .taste = g_cache_taste,
  102         .destroy_geom = g_cache_destroy_geom
  103 };
  104 
  105 #define OFF2BNO(off, sc)        ((off) >> (sc)->sc_bshift)
  106 #define BNO2OFF(bno, sc)        ((bno) << (sc)->sc_bshift)
  107 
  108 
  109 static struct g_cache_desc *
  110 g_cache_alloc(struct g_cache_softc *sc)
  111 {
  112         struct g_cache_desc *dp;
  113 
  114         mtx_assert(&sc->sc_mtx, MA_OWNED);
  115 
  116         if (!TAILQ_EMPTY(&sc->sc_usedlist)) {
  117                 dp = TAILQ_FIRST(&sc->sc_usedlist);
  118                 TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
  119                 sc->sc_nused--;
  120                 dp->d_flags = 0;
  121                 LIST_REMOVE(dp, d_next);
  122                 return (dp);
  123         }
  124         if (sc->sc_nent > sc->sc_maxent) {
  125                 sc->sc_cachefull++;
  126                 return (NULL);
  127         }
  128         dp = malloc(sizeof(*dp), M_GCACHE, M_NOWAIT | M_ZERO);
  129         if (dp == NULL)
  130                 return (NULL);
  131         dp->d_data = uma_zalloc(sc->sc_zone, M_NOWAIT);
  132         if (dp->d_data == NULL) {
  133                 free(dp, M_GCACHE);
  134                 return (NULL);
  135         }
  136         sc->sc_nent++;
  137         return (dp);
  138 }
  139 
  140 static void
  141 g_cache_free(struct g_cache_softc *sc, struct g_cache_desc *dp)
  142 {
  143 
  144         mtx_assert(&sc->sc_mtx, MA_OWNED);
  145 
  146         uma_zfree(sc->sc_zone, dp->d_data);
  147         free(dp, M_GCACHE);
  148         sc->sc_nent--;
  149 }
  150 
  151 static void
  152 g_cache_free_used(struct g_cache_softc *sc)
  153 {
  154         struct g_cache_desc *dp;
  155         u_int n;
  156 
  157         mtx_assert(&sc->sc_mtx, MA_OWNED);
  158 
  159         n = g_cache_used_lo * sc->sc_maxent / 100;
  160         while (sc->sc_nused > n) {
  161                 KASSERT(!TAILQ_EMPTY(&sc->sc_usedlist), ("used list empty"));
  162                 dp = TAILQ_FIRST(&sc->sc_usedlist);
  163                 TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
  164                 sc->sc_nused--;
  165                 LIST_REMOVE(dp, d_next);
  166                 g_cache_free(sc, dp);
  167         }
  168 }
  169 
  170 static void
  171 g_cache_deliver(struct g_cache_softc *sc, struct bio *bp,
  172     struct g_cache_desc *dp, int error)
  173 {
  174         off_t off1, off, len;
  175 
  176         mtx_assert(&sc->sc_mtx, MA_OWNED);
  177         KASSERT(OFF2BNO(bp->bio_offset, sc) <= dp->d_bno, ("wrong entry"));
  178         KASSERT(OFF2BNO(bp->bio_offset + bp->bio_length - 1, sc) >=
  179             dp->d_bno, ("wrong entry"));
  180 
  181         off1 = BNO2OFF(dp->d_bno, sc);
  182         off = MAX(bp->bio_offset, off1);
  183         len = MIN(bp->bio_offset + bp->bio_length, off1 + sc->sc_bsize) - off;
  184 
  185         if (bp->bio_error == 0)
  186                 bp->bio_error = error;
  187         if (bp->bio_error == 0) {
  188                 bcopy(dp->d_data + (off - off1),
  189                     bp->bio_data + (off - bp->bio_offset), len);
  190         }
  191         bp->bio_completed += len;
  192         KASSERT(bp->bio_completed <= bp->bio_length, ("extra data"));
  193         if (bp->bio_completed == bp->bio_length) {
  194                 if (bp->bio_error != 0)
  195                         bp->bio_completed = 0;
  196                 g_io_deliver(bp, bp->bio_error);
  197         }
  198 
  199         if (dp->d_flags & D_FLAG_USED) {
  200                 TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
  201                 TAILQ_INSERT_TAIL(&sc->sc_usedlist, dp, d_used);
  202         } else if (OFF2BNO(off + len, sc) > dp->d_bno) {
  203                 TAILQ_INSERT_TAIL(&sc->sc_usedlist, dp, d_used);
  204                 sc->sc_nused++;
  205                 dp->d_flags |= D_FLAG_USED;
  206         }
  207         dp->d_atime = time_uptime;
  208 }
  209 
  210 static void
  211 g_cache_done(struct bio *bp)
  212 {
  213         struct g_cache_softc *sc;
  214         struct g_cache_desc *dp;
  215         struct bio *bp2, *tmpbp;
  216 
  217         sc = bp->bio_from->geom->softc;
  218         KASSERT(G_CACHE_DESC1(bp) == sc, ("corrupt bio_caller in g_cache_done()"));
  219         dp = G_CACHE_DESC2(bp);
  220         mtx_lock(&sc->sc_mtx);
  221         bp2 = dp->d_biolist;
  222         while (bp2 != NULL) {
  223                 KASSERT(G_CACHE_NEXT_BIO1(bp2) == sc, ("corrupt bio_driver in g_cache_done()"));
  224                 tmpbp = G_CACHE_NEXT_BIO2(bp2);
  225                 g_cache_deliver(sc, bp2, dp, bp->bio_error);
  226                 bp2 = tmpbp;
  227         }
  228         dp->d_biolist = NULL;
  229         if (dp->d_flags & D_FLAG_INVALID) {
  230                 sc->sc_invalid--;
  231                 g_cache_free(sc, dp);
  232         } else if (bp->bio_error) {
  233                 LIST_REMOVE(dp, d_next);
  234                 if (dp->d_flags & D_FLAG_USED) {
  235                         TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
  236                         sc->sc_nused--;
  237                 }
  238                 g_cache_free(sc, dp);
  239         }
  240         mtx_unlock(&sc->sc_mtx);
  241         g_destroy_bio(bp);
  242 }
  243 
  244 static struct g_cache_desc *
  245 g_cache_lookup(struct g_cache_softc *sc, off_t bno)
  246 {
  247         struct g_cache_desc *dp;
  248 
  249         mtx_assert(&sc->sc_mtx, MA_OWNED);
  250 
  251         LIST_FOREACH(dp, &sc->sc_desclist[G_CACHE_BUCKET(bno)], d_next)
  252                 if (dp->d_bno == bno)
  253                         return (dp);
  254         return (NULL);
  255 }
  256 
  257 static int
  258 g_cache_read(struct g_cache_softc *sc, struct bio *bp)
  259 {
  260         struct bio *cbp;
  261         struct g_cache_desc *dp;
  262 
  263         mtx_lock(&sc->sc_mtx);
  264         dp = g_cache_lookup(sc,
  265             OFF2BNO(bp->bio_offset + bp->bio_completed, sc));
  266         if (dp != NULL) {
  267                 /* Add to waiters list or deliver. */
  268                 sc->sc_cachehits++;
  269                 if (dp->d_biolist != NULL) {
  270                         G_CACHE_NEXT_BIO1(bp) = sc;
  271                         G_CACHE_NEXT_BIO2(bp) = dp->d_biolist;
  272                         dp->d_biolist = bp;
  273                 } else
  274                         g_cache_deliver(sc, bp, dp, 0);
  275                 mtx_unlock(&sc->sc_mtx);
  276                 return (0);
  277         }
  278 
  279         /* Cache miss.  Allocate entry and schedule bio.  */
  280         sc->sc_cachemisses++;
  281         dp = g_cache_alloc(sc);
  282         if (dp == NULL) {
  283                 mtx_unlock(&sc->sc_mtx);
  284                 return (ENOMEM);
  285         }
  286         cbp = g_clone_bio(bp);
  287         if (cbp == NULL) {
  288                 g_cache_free(sc, dp);
  289                 mtx_unlock(&sc->sc_mtx);
  290                 return (ENOMEM);
  291         }
  292 
  293         dp->d_bno = OFF2BNO(bp->bio_offset + bp->bio_completed, sc);
  294         G_CACHE_NEXT_BIO1(bp) = sc;
  295         G_CACHE_NEXT_BIO2(bp) = NULL;
  296         dp->d_biolist = bp;
  297         LIST_INSERT_HEAD(&sc->sc_desclist[G_CACHE_BUCKET(dp->d_bno)],
  298             dp, d_next);
  299         mtx_unlock(&sc->sc_mtx);
  300 
  301         G_CACHE_DESC1(cbp) = sc;
  302         G_CACHE_DESC2(cbp) = dp;
  303         cbp->bio_done = g_cache_done;
  304         cbp->bio_offset = BNO2OFF(dp->d_bno, sc);
  305         cbp->bio_data = dp->d_data;
  306         cbp->bio_length = sc->sc_bsize;
  307         g_io_request(cbp, LIST_FIRST(&bp->bio_to->geom->consumer));
  308         return (0);
  309 }
  310 
  311 static void
  312 g_cache_invalidate(struct g_cache_softc *sc, struct bio *bp)
  313 {
  314         struct g_cache_desc *dp;
  315         off_t bno, lim;
  316 
  317         mtx_lock(&sc->sc_mtx);
  318         bno = OFF2BNO(bp->bio_offset, sc);
  319         lim = OFF2BNO(bp->bio_offset + bp->bio_length - 1, sc);
  320         do {
  321                 if ((dp = g_cache_lookup(sc, bno)) != NULL) {
  322                         LIST_REMOVE(dp, d_next);
  323                         if (dp->d_flags & D_FLAG_USED) {
  324                                 TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
  325                                 sc->sc_nused--;
  326                         }
  327                         if (dp->d_biolist == NULL)
  328                                 g_cache_free(sc, dp);
  329                         else {
  330                                 dp->d_flags = D_FLAG_INVALID;
  331                                 sc->sc_invalid++;
  332                         }
  333                 }
  334                 bno++;
  335         } while (bno <= lim);
  336         mtx_unlock(&sc->sc_mtx);
  337 }
  338 
  339 static void
  340 g_cache_start(struct bio *bp)
  341 {
  342         struct g_cache_softc *sc;
  343         struct g_geom *gp;
  344         struct g_cache_desc *dp;
  345         struct bio *cbp;
  346 
  347         gp = bp->bio_to->geom;
  348         sc = gp->softc;
  349         G_CACHE_LOGREQ(bp, "Request received.");
  350         switch (bp->bio_cmd) {
  351         case BIO_READ:
  352                 sc->sc_reads++;
  353                 sc->sc_readbytes += bp->bio_length;
  354                 if (!g_cache_enable)
  355                         break;
  356                 if (bp->bio_offset + bp->bio_length > sc->sc_tail)
  357                         break;
  358                 if (OFF2BNO(bp->bio_offset, sc) ==
  359                     OFF2BNO(bp->bio_offset + bp->bio_length - 1, sc)) {
  360                         sc->sc_cachereads++;
  361                         sc->sc_cachereadbytes += bp->bio_length;
  362                         if (g_cache_read(sc, bp) == 0)
  363                                 return;
  364                         sc->sc_cachereads--;
  365                         sc->sc_cachereadbytes -= bp->bio_length;
  366                         break;
  367                 } else if (OFF2BNO(bp->bio_offset, sc) + 1 ==
  368                     OFF2BNO(bp->bio_offset + bp->bio_length - 1, sc)) {
  369                         mtx_lock(&sc->sc_mtx);
  370                         dp = g_cache_lookup(sc, OFF2BNO(bp->bio_offset, sc));
  371                         if (dp == NULL || dp->d_biolist != NULL) {
  372                                 mtx_unlock(&sc->sc_mtx);
  373                                 break;
  374                         }
  375                         sc->sc_cachereads++;
  376                         sc->sc_cachereadbytes += bp->bio_length;
  377                         g_cache_deliver(sc, bp, dp, 0);
  378                         mtx_unlock(&sc->sc_mtx);
  379                         if (g_cache_read(sc, bp) == 0)
  380                                 return;
  381                         sc->sc_cachereads--;
  382                         sc->sc_cachereadbytes -= bp->bio_length;
  383                         break;
  384                 }
  385                 break;
  386         case BIO_WRITE:
  387                 sc->sc_writes++;
  388                 sc->sc_wrotebytes += bp->bio_length;
  389                 g_cache_invalidate(sc, bp);
  390                 break;
  391         }
  392         cbp = g_clone_bio(bp);
  393         if (cbp == NULL) {
  394                 g_io_deliver(bp, ENOMEM);
  395                 return;
  396         }
  397         cbp->bio_done = g_std_done;
  398         G_CACHE_LOGREQ(cbp, "Sending request.");
  399         g_io_request(cbp, LIST_FIRST(&gp->consumer));
  400 }
  401 
  402 static void
  403 g_cache_go(void *arg)
  404 {
  405         struct g_cache_softc *sc = arg;
  406         struct g_cache_desc *dp;
  407         int i;
  408 
  409         mtx_assert(&sc->sc_mtx, MA_OWNED);
  410 
  411         /* Forcibly mark idle ready entries as used. */
  412         for (i = 0; i < G_CACHE_BUCKETS; i++) {
  413                 LIST_FOREACH(dp, &sc->sc_desclist[i], d_next) {
  414                         if (dp->d_flags & D_FLAG_USED ||
  415                             dp->d_biolist != NULL ||
  416                             time_uptime - dp->d_atime < g_cache_idletime)
  417                                 continue;
  418                         TAILQ_INSERT_TAIL(&sc->sc_usedlist, dp, d_used);
  419                         sc->sc_nused++;
  420                         dp->d_flags |= D_FLAG_USED;
  421                 }
  422         }
  423 
  424         /* Keep the number of used entries low. */
  425         if (sc->sc_nused > g_cache_used_hi * sc->sc_maxent / 100)
  426                 g_cache_free_used(sc);
  427 
  428         callout_reset(&sc->sc_callout, g_cache_timeout * hz, g_cache_go, sc);
  429 }
  430 
  431 static int
  432 g_cache_access(struct g_provider *pp, int dr, int dw, int de)
  433 {
  434         struct g_geom *gp;
  435         struct g_consumer *cp;
  436         int error;
  437 
  438         gp = pp->geom;
  439         cp = LIST_FIRST(&gp->consumer);
  440         error = g_access(cp, dr, dw, de);
  441 
  442         return (error);
  443 }
  444 
  445 static void
  446 g_cache_orphan(struct g_consumer *cp)
  447 {
  448 
  449         g_topology_assert();
  450         g_cache_destroy(cp->geom->softc, 1);
  451 }
  452 
  453 static struct g_cache_softc *
  454 g_cache_find_device(struct g_class *mp, const char *name)
  455 {
  456         struct g_geom *gp;
  457 
  458         LIST_FOREACH(gp, &mp->geom, geom) {
  459                 if (strcmp(gp->name, name) == 0)
  460                         return (gp->softc);
  461         }
  462         return (NULL);
  463 }
  464 
  465 static struct g_geom *
  466 g_cache_create(struct g_class *mp, struct g_provider *pp,
  467     const struct g_cache_metadata *md, u_int type)
  468 {
  469         struct g_cache_softc *sc;
  470         struct g_geom *gp;
  471         struct g_provider *newpp;
  472         struct g_consumer *cp;
  473         u_int bshift;
  474         int i;
  475 
  476         g_topology_assert();
  477 
  478         gp = NULL;
  479         newpp = NULL;
  480         cp = NULL;
  481 
  482         G_CACHE_DEBUG(1, "Creating device %s.", md->md_name);
  483 
  484         /* Cache size is minimum 100. */
  485         if (md->md_size < 100) {
  486                 G_CACHE_DEBUG(0, "Invalid size for device %s.", md->md_name);
  487                 return (NULL);
  488         }
  489 
  490         /* Block size restrictions. */
  491         bshift = ffs(md->md_bsize) - 1;
  492         if (md->md_bsize == 0 || md->md_bsize > MAXPHYS ||
  493             md->md_bsize != 1 << bshift ||
  494             (md->md_bsize % pp->sectorsize) != 0) {
  495                 G_CACHE_DEBUG(0, "Invalid blocksize for provider %s.", pp->name);
  496                 return (NULL);
  497         }
  498 
  499         /* Check for duplicate unit. */
  500         if (g_cache_find_device(mp, (const char *)&md->md_name) != NULL) {
  501                 G_CACHE_DEBUG(0, "Provider %s already exists.", md->md_name);
  502                 return (NULL);
  503         }
  504 
  505         gp = g_new_geomf(mp, "%s", md->md_name);
  506         sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
  507         sc->sc_type = type;
  508         sc->sc_bshift = bshift;
  509         sc->sc_bsize = 1 << bshift;
  510         sc->sc_zone = uma_zcreate("gcache", sc->sc_bsize, NULL, NULL, NULL, NULL,
  511             UMA_ALIGN_PTR, 0);
  512         mtx_init(&sc->sc_mtx, "GEOM CACHE mutex", NULL, MTX_DEF);
  513         for (i = 0; i < G_CACHE_BUCKETS; i++)
  514                 LIST_INIT(&sc->sc_desclist[i]);
  515         TAILQ_INIT(&sc->sc_usedlist);
  516         sc->sc_maxent = md->md_size;
  517         callout_init_mtx(&sc->sc_callout, &sc->sc_mtx, 0);
  518         gp->softc = sc;
  519         sc->sc_geom = gp;
  520         gp->start = g_cache_start;
  521         gp->orphan = g_cache_orphan;
  522         gp->access = g_cache_access;
  523         gp->dumpconf = g_cache_dumpconf;
  524 
  525         newpp = g_new_providerf(gp, "cache/%s", gp->name);
  526         newpp->sectorsize = pp->sectorsize;
  527         newpp->mediasize = pp->mediasize;
  528         if (type == G_CACHE_TYPE_AUTOMATIC)
  529                 newpp->mediasize -= pp->sectorsize;
  530         sc->sc_tail = BNO2OFF(OFF2BNO(newpp->mediasize, sc), sc);
  531 
  532         cp = g_new_consumer(gp);
  533         if (g_attach(cp, pp) != 0) {
  534                 G_CACHE_DEBUG(0, "Cannot attach to provider %s.", pp->name);
  535                 g_destroy_consumer(cp);
  536                 g_destroy_provider(newpp);
  537                 mtx_destroy(&sc->sc_mtx);
  538                 g_free(sc);
  539                 g_destroy_geom(gp);
  540                 return (NULL);
  541         }
  542 
  543         g_error_provider(newpp, 0);
  544         G_CACHE_DEBUG(0, "Device %s created.", gp->name);
  545         callout_reset(&sc->sc_callout, g_cache_timeout * hz, g_cache_go, sc);
  546         return (gp);
  547 }
  548 
  549 static int
  550 g_cache_destroy(struct g_cache_softc *sc, boolean_t force)
  551 {
  552         struct g_geom *gp;
  553         struct g_provider *pp;
  554         struct g_cache_desc *dp, *dp2;
  555         int i;
  556 
  557         g_topology_assert();
  558         if (sc == NULL)
  559                 return (ENXIO);
  560         gp = sc->sc_geom;
  561         pp = LIST_FIRST(&gp->provider);
  562         if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
  563                 if (force) {
  564                         G_CACHE_DEBUG(0, "Device %s is still open, so it "
  565                             "can't be definitely removed.", pp->name);
  566                 } else {
  567                         G_CACHE_DEBUG(1, "Device %s is still open (r%dw%de%d).",
  568                             pp->name, pp->acr, pp->acw, pp->ace);
  569                         return (EBUSY);
  570                 }
  571         } else {
  572                 G_CACHE_DEBUG(0, "Device %s removed.", gp->name);
  573         }
  574         callout_drain(&sc->sc_callout);
  575         mtx_lock(&sc->sc_mtx);
  576         for (i = 0; i < G_CACHE_BUCKETS; i++) {
  577                 dp = LIST_FIRST(&sc->sc_desclist[i]);
  578                 while (dp != NULL) {
  579                         dp2 = LIST_NEXT(dp, d_next);
  580                         g_cache_free(sc, dp);
  581                         dp = dp2;
  582                 }
  583         }
  584         mtx_unlock(&sc->sc_mtx);
  585         mtx_destroy(&sc->sc_mtx);
  586         uma_zdestroy(sc->sc_zone);
  587         g_free(sc);
  588         gp->softc = NULL;
  589         g_wither_geom(gp, ENXIO);
  590 
  591         return (0);
  592 }
  593 
  594 static int
  595 g_cache_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
  596 {
  597 
  598         return (g_cache_destroy(gp->softc, 0));
  599 }
  600 
  601 static int
  602 g_cache_read_metadata(struct g_consumer *cp, struct g_cache_metadata *md)
  603 {
  604         struct g_provider *pp;
  605         u_char *buf;
  606         int error;
  607 
  608         g_topology_assert();
  609 
  610         error = g_access(cp, 1, 0, 0);
  611         if (error != 0)
  612                 return (error);
  613         pp = cp->provider;
  614         g_topology_unlock();
  615         buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
  616             &error);
  617         g_topology_lock();
  618         g_access(cp, -1, 0, 0);
  619         if (buf == NULL)
  620                 return (error);
  621 
  622         /* Decode metadata. */
  623         cache_metadata_decode(buf, md);
  624         g_free(buf);
  625 
  626         return (0);
  627 }
  628 
  629 static int
  630 g_cache_write_metadata(struct g_consumer *cp, struct g_cache_metadata *md)
  631 {
  632         struct g_provider *pp;
  633         u_char *buf;
  634         int error;
  635 
  636         g_topology_assert();
  637 
  638         error = g_access(cp, 0, 1, 0);
  639         if (error != 0)
  640                 return (error);
  641         pp = cp->provider;
  642         buf = malloc((size_t)pp->sectorsize, M_GCACHE, M_WAITOK | M_ZERO);
  643         cache_metadata_encode(md, buf);
  644         g_topology_unlock();
  645         error = g_write_data(cp, pp->mediasize - pp->sectorsize, buf, pp->sectorsize);
  646         g_topology_lock();
  647         g_access(cp, 0, -1, 0);
  648         free(buf, M_GCACHE);
  649 
  650         return (error);
  651 }
  652 
  653 static struct g_geom *
  654 g_cache_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
  655 {
  656         struct g_cache_metadata md;
  657         struct g_consumer *cp;
  658         struct g_geom *gp;
  659         int error;
  660 
  661         g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
  662         g_topology_assert();
  663 
  664         G_CACHE_DEBUG(3, "Tasting %s.", pp->name);
  665 
  666         gp = g_new_geomf(mp, "cache:taste");
  667         gp->start = g_cache_start;
  668         gp->orphan = g_cache_orphan;
  669         gp->access = g_cache_access;
  670         cp = g_new_consumer(gp);
  671         g_attach(cp, pp);
  672         error = g_cache_read_metadata(cp, &md);
  673         g_detach(cp);
  674         g_destroy_consumer(cp);
  675         g_destroy_geom(gp);
  676         if (error != 0)
  677                 return (NULL);
  678 
  679         if (strcmp(md.md_magic, G_CACHE_MAGIC) != 0)
  680                 return (NULL);
  681         if (md.md_version > G_CACHE_VERSION) {
  682                 printf("geom_cache.ko module is too old to handle %s.\n",
  683                     pp->name);
  684                 return (NULL);
  685         }
  686         if (md.md_provsize != pp->mediasize)
  687                 return (NULL);
  688 
  689         gp = g_cache_create(mp, pp, &md, G_CACHE_TYPE_AUTOMATIC);
  690         if (gp == NULL) {
  691                 G_CACHE_DEBUG(0, "Can't create %s.", md.md_name);
  692                 return (NULL);
  693         }
  694         return (gp);
  695 }
  696 
  697 static void
  698 g_cache_ctl_create(struct gctl_req *req, struct g_class *mp)
  699 {
  700         struct g_cache_metadata md;
  701         struct g_provider *pp;
  702         struct g_geom *gp;
  703         intmax_t *bsize, *size;
  704         const char *name;
  705         int *nargs;
  706 
  707         g_topology_assert();
  708 
  709         nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
  710         if (nargs == NULL) {
  711                 gctl_error(req, "No '%s' argument", "nargs");
  712                 return;
  713         }
  714         if (*nargs != 2) {
  715                 gctl_error(req, "Invalid number of arguments.");
  716                 return;
  717         }
  718 
  719         strlcpy(md.md_magic, G_CACHE_MAGIC, sizeof(md.md_magic));
  720         md.md_version = G_CACHE_VERSION;
  721         name = gctl_get_asciiparam(req, "arg0");
  722         if (name == NULL) {
  723                 gctl_error(req, "No 'arg0' argument");
  724                 return;
  725         }
  726         strlcpy(md.md_name, name, sizeof(md.md_name));
  727 
  728         size = gctl_get_paraml(req, "size", sizeof(*size));
  729         if (size == NULL) {
  730                 gctl_error(req, "No '%s' argument", "size");
  731                 return;
  732         }
  733         if ((u_int)*size < 100) {
  734                 gctl_error(req, "Invalid '%s' argument", "size");
  735                 return;
  736         }
  737         md.md_size = (u_int)*size;
  738 
  739         bsize = gctl_get_paraml(req, "blocksize", sizeof(*bsize));
  740         if (bsize == NULL) {
  741                 gctl_error(req, "No '%s' argument", "blocksize");
  742                 return;
  743         }
  744         if (*bsize < 0) {
  745                 gctl_error(req, "Invalid '%s' argument", "blocksize");
  746                 return;
  747         }
  748         md.md_bsize = (u_int)*bsize;
  749 
  750         /* This field is not important here. */
  751         md.md_provsize = 0;
  752 
  753         name = gctl_get_asciiparam(req, "arg1");
  754         if (name == NULL) {
  755                 gctl_error(req, "No 'arg1' argument");
  756                 return;
  757         }
  758         if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
  759                 name += strlen("/dev/");
  760         pp = g_provider_by_name(name);
  761         if (pp == NULL) {
  762                 G_CACHE_DEBUG(1, "Provider %s is invalid.", name);
  763                 gctl_error(req, "Provider %s is invalid.", name);
  764                 return;
  765         }
  766         gp = g_cache_create(mp, pp, &md, G_CACHE_TYPE_MANUAL);
  767         if (gp == NULL) {
  768                 gctl_error(req, "Can't create %s.", md.md_name);
  769                 return;
  770         }
  771 }
  772 
  773 static void
  774 g_cache_ctl_configure(struct gctl_req *req, struct g_class *mp)
  775 {
  776         struct g_cache_metadata md;
  777         struct g_cache_softc *sc;
  778         struct g_consumer *cp;
  779         intmax_t *bsize, *size;
  780         const char *name;
  781         int error, *nargs;
  782 
  783         g_topology_assert();
  784 
  785         nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
  786         if (nargs == NULL) {
  787                 gctl_error(req, "No '%s' argument", "nargs");
  788                 return;
  789         }
  790         if (*nargs != 1) {
  791                 gctl_error(req, "Missing device.");
  792                 return;
  793         }
  794 
  795         name = gctl_get_asciiparam(req, "arg0");
  796         if (name == NULL) {
  797                 gctl_error(req, "No 'arg0' argument");
  798                 return;
  799         }
  800         sc = g_cache_find_device(mp, name);
  801         if (sc == NULL) {
  802                 G_CACHE_DEBUG(1, "Device %s is invalid.", name);
  803                 gctl_error(req, "Device %s is invalid.", name);
  804                 return;
  805         }
  806 
  807         size = gctl_get_paraml(req, "size", sizeof(*size));
  808         if (size == NULL) {
  809                 gctl_error(req, "No '%s' argument", "size");
  810                 return;
  811         }
  812         if ((u_int)*size != 0 && (u_int)*size < 100) {
  813                 gctl_error(req, "Invalid '%s' argument", "size");
  814                 return;
  815         }
  816         if ((u_int)*size != 0)
  817                 sc->sc_maxent = (u_int)*size;
  818 
  819         bsize = gctl_get_paraml(req, "blocksize", sizeof(*bsize));
  820         if (bsize == NULL) {
  821                 gctl_error(req, "No '%s' argument", "blocksize");
  822                 return;
  823         }
  824         if (*bsize < 0) {
  825                 gctl_error(req, "Invalid '%s' argument", "blocksize");
  826                 return;
  827         }
  828 
  829         if (sc->sc_type != G_CACHE_TYPE_AUTOMATIC)
  830                 return;
  831 
  832         strlcpy(md.md_name, name, sizeof(md.md_name));
  833         strlcpy(md.md_magic, G_CACHE_MAGIC, sizeof(md.md_magic));
  834         md.md_version = G_CACHE_VERSION;
  835         if ((u_int)*size != 0)
  836                 md.md_size = (u_int)*size;
  837         else
  838                 md.md_size = sc->sc_maxent;
  839         if ((u_int)*bsize != 0)
  840                 md.md_bsize = (u_int)*bsize;
  841         else
  842                 md.md_bsize = sc->sc_bsize;
  843         cp = LIST_FIRST(&sc->sc_geom->consumer);
  844         md.md_provsize = cp->provider->mediasize;
  845         error = g_cache_write_metadata(cp, &md);
  846         if (error == 0)
  847                 G_CACHE_DEBUG(2, "Metadata on %s updated.", cp->provider->name);
  848         else
  849                 G_CACHE_DEBUG(0, "Cannot update metadata on %s (error=%d).",
  850                     cp->provider->name, error);
  851 }
  852 
  853 static void
  854 g_cache_ctl_destroy(struct gctl_req *req, struct g_class *mp)
  855 {
  856         int *nargs, *force, error, i;
  857         struct g_cache_softc *sc;
  858         const char *name;
  859         char param[16];
  860 
  861         g_topology_assert();
  862 
  863         nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
  864         if (nargs == NULL) {
  865                 gctl_error(req, "No '%s' argument", "nargs");
  866                 return;
  867         }
  868         if (*nargs <= 0) {
  869                 gctl_error(req, "Missing device(s).");
  870                 return;
  871         }
  872         force = gctl_get_paraml(req, "force", sizeof(*force));
  873         if (force == NULL) {
  874                 gctl_error(req, "No 'force' argument");
  875                 return;
  876         }
  877 
  878         for (i = 0; i < *nargs; i++) {
  879                 snprintf(param, sizeof(param), "arg%d", i);
  880                 name = gctl_get_asciiparam(req, param);
  881                 if (name == NULL) {
  882                         gctl_error(req, "No 'arg%d' argument", i);
  883                         return;
  884                 }
  885                 sc = g_cache_find_device(mp, name);
  886                 if (sc == NULL) {
  887                         G_CACHE_DEBUG(1, "Device %s is invalid.", name);
  888                         gctl_error(req, "Device %s is invalid.", name);
  889                         return;
  890                 }
  891                 error = g_cache_destroy(sc, *force);
  892                 if (error != 0) {
  893                         gctl_error(req, "Cannot destroy device %s (error=%d).",
  894                             sc->sc_name, error);
  895                         return;
  896                 }
  897         }
  898 }
  899 
  900 static void
  901 g_cache_ctl_reset(struct gctl_req *req, struct g_class *mp)
  902 {
  903         struct g_cache_softc *sc;
  904         const char *name;
  905         char param[16];
  906         int i, *nargs;
  907 
  908         g_topology_assert();
  909 
  910         nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
  911         if (nargs == NULL) {
  912                 gctl_error(req, "No '%s' argument", "nargs");
  913                 return;
  914         }
  915         if (*nargs <= 0) {
  916                 gctl_error(req, "Missing device(s).");
  917                 return;
  918         }
  919 
  920         for (i = 0; i < *nargs; i++) {
  921                 snprintf(param, sizeof(param), "arg%d", i);
  922                 name = gctl_get_asciiparam(req, param);
  923                 if (name == NULL) {
  924                         gctl_error(req, "No 'arg%d' argument", i);
  925                         return;
  926                 }
  927                 sc = g_cache_find_device(mp, name);
  928                 if (sc == NULL) {
  929                         G_CACHE_DEBUG(1, "Device %s is invalid.", name);
  930                         gctl_error(req, "Device %s is invalid.", name);
  931                         return;
  932                 }
  933                 sc->sc_reads = 0;
  934                 sc->sc_readbytes = 0;
  935                 sc->sc_cachereads = 0;
  936                 sc->sc_cachereadbytes = 0;
  937                 sc->sc_cachehits = 0;
  938                 sc->sc_cachemisses = 0;
  939                 sc->sc_cachefull = 0;
  940                 sc->sc_writes = 0;
  941                 sc->sc_wrotebytes = 0;
  942         }
  943 }
  944 
  945 static void
  946 g_cache_config(struct gctl_req *req, struct g_class *mp, const char *verb)
  947 {
  948         uint32_t *version;
  949 
  950         g_topology_assert();
  951 
  952         version = gctl_get_paraml(req, "version", sizeof(*version));
  953         if (version == NULL) {
  954                 gctl_error(req, "No '%s' argument.", "version");
  955                 return;
  956         }
  957         if (*version != G_CACHE_VERSION) {
  958                 gctl_error(req, "Userland and kernel parts are out of sync.");
  959                 return;
  960         }
  961 
  962         if (strcmp(verb, "create") == 0) {
  963                 g_cache_ctl_create(req, mp);
  964                 return;
  965         } else if (strcmp(verb, "configure") == 0) {
  966                 g_cache_ctl_configure(req, mp);
  967                 return;
  968         } else if (strcmp(verb, "destroy") == 0 ||
  969             strcmp(verb, "stop") == 0) {
  970                 g_cache_ctl_destroy(req, mp);
  971                 return;
  972         } else if (strcmp(verb, "reset") == 0) {
  973                 g_cache_ctl_reset(req, mp);
  974                 return;
  975         }
  976 
  977         gctl_error(req, "Unknown verb.");
  978 }
  979 
  980 static void
  981 g_cache_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
  982     struct g_consumer *cp, struct g_provider *pp)
  983 {
  984         struct g_cache_softc *sc;
  985 
  986         if (pp != NULL || cp != NULL)
  987                 return;
  988         sc = gp->softc;
  989         sbuf_printf(sb, "%s<Size>%u</Size>\n", indent, sc->sc_maxent);
  990         sbuf_printf(sb, "%s<BlockSize>%u</BlockSize>\n", indent, sc->sc_bsize);
  991         sbuf_printf(sb, "%s<TailOffset>%ju</TailOffset>\n", indent,
  992             (uintmax_t)sc->sc_tail);
  993         sbuf_printf(sb, "%s<Entries>%u</Entries>\n", indent, sc->sc_nent);
  994         sbuf_printf(sb, "%s<UsedEntries>%u</UsedEntries>\n", indent,
  995             sc->sc_nused);
  996         sbuf_printf(sb, "%s<InvalidEntries>%u</InvalidEntries>\n", indent,
  997             sc->sc_invalid);
  998         sbuf_printf(sb, "%s<Reads>%ju</Reads>\n", indent, sc->sc_reads);
  999         sbuf_printf(sb, "%s<ReadBytes>%ju</ReadBytes>\n", indent,
 1000             sc->sc_readbytes);
 1001         sbuf_printf(sb, "%s<CacheReads>%ju</CacheReads>\n", indent,
 1002             sc->sc_cachereads);
 1003         sbuf_printf(sb, "%s<CacheReadBytes>%ju</CacheReadBytes>\n", indent,
 1004             sc->sc_cachereadbytes);
 1005         sbuf_printf(sb, "%s<CacheHits>%ju</CacheHits>\n", indent,
 1006             sc->sc_cachehits);
 1007         sbuf_printf(sb, "%s<CacheMisses>%ju</CacheMisses>\n", indent,
 1008             sc->sc_cachemisses);
 1009         sbuf_printf(sb, "%s<CacheFull>%ju</CacheFull>\n", indent,
 1010             sc->sc_cachefull);
 1011         sbuf_printf(sb, "%s<Writes>%ju</Writes>\n", indent, sc->sc_writes);
 1012         sbuf_printf(sb, "%s<WroteBytes>%ju</WroteBytes>\n", indent,
 1013             sc->sc_wrotebytes);
 1014 }
 1015 
 1016 DECLARE_GEOM_CLASS(g_cache_class, g_cache);

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