geom_io.c

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    1 /*-
    2  * Copyright (c) 2002 Poul-Henning Kamp
    3  * Copyright (c) 2002 Networks Associates Technology, Inc.
    4  * All rights reserved.
    5  *
    6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
    7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
    8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
    9  * DARPA CHATS research program.
   10  *
   11  * Redistribution and use in source and binary forms, with or without
   12  * modification, are permitted provided that the following conditions
   13  * are met:
   14  * 1. Redistributions of source code must retain the above copyright
   15  *    notice, this list of conditions and the following disclaimer.
   16  * 2. Redistributions in binary form must reproduce the above copyright
   17  *    notice, this list of conditions and the following disclaimer in the
   18  *    documentation and/or other materials provided with the distribution.
   19  * 3. The names of the authors may not be used to endorse or promote
   20  *    products derived from this software without specific prior written
   21  *    permission.
   22  *
   23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   33  * SUCH DAMAGE.
   34  */
   35 
   36 #include <sys/cdefs.h>
   37 __FBSDID("$FreeBSD: releng/5.2/sys/geom/geom_io.c 125692 2004-02-11 08:31:23Z scottl $");
   38 
   39 #include <sys/param.h>
   40 #include <sys/systm.h>
   41 #include <sys/kernel.h>
   42 #include <sys/malloc.h>
   43 #include <sys/bio.h>
   44 
   45 #include <sys/errno.h>
   46 #include <geom/geom.h>
   47 #include <geom/geom_int.h>
   48 #include <sys/devicestat.h>
   49 
   50 #include <vm/uma.h>
   51 
   52 static struct g_bioq g_bio_run_down;
   53 static struct g_bioq g_bio_run_up;
   54 static struct g_bioq g_bio_run_task;
   55 
   56 static u_int pace;
   57 static uma_zone_t       biozone;
   58 
   59 #include <machine/atomic.h>
   60 
   61 static void
   62 g_bioq_lock(struct g_bioq *bq)
   63 {
   64 
   65         mtx_lock(&bq->bio_queue_lock);
   66 }
   67 
   68 static void
   69 g_bioq_unlock(struct g_bioq *bq)
   70 {
   71 
   72         mtx_unlock(&bq->bio_queue_lock);
   73 }
   74 
   75 #if 0
   76 static void
   77 g_bioq_destroy(struct g_bioq *bq)
   78 {
   79 
   80         mtx_destroy(&bq->bio_queue_lock);
   81 }
   82 #endif
   83 
   84 static void
   85 g_bioq_init(struct g_bioq *bq)
   86 {
   87 
   88         TAILQ_INIT(&bq->bio_queue);
   89         mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
   90 }
   91 
   92 static struct bio *
   93 g_bioq_first(struct g_bioq *bq)
   94 {
   95         struct bio *bp;
   96 
   97         bp = TAILQ_FIRST(&bq->bio_queue);
   98         if (bp != NULL) {
   99                 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
  100                 bq->bio_queue_length--;
  101         }
  102         return (bp);
  103 }
  104 
  105 static void
  106 g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq)
  107 {
  108 
  109         g_bioq_lock(rq);
  110         TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue);
  111         rq->bio_queue_length++;
  112         g_bioq_unlock(rq);
  113 }
  114 
  115 struct bio *
  116 g_new_bio(void)
  117 {
  118         struct bio *bp;
  119 
  120         bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
  121         return (bp);
  122 }
  123 
  124 void
  125 g_destroy_bio(struct bio *bp)
  126 {
  127 
  128         uma_zfree(biozone, bp);
  129 }
  130 
  131 struct bio *
  132 g_clone_bio(struct bio *bp)
  133 {
  134         struct bio *bp2;
  135 
  136         bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
  137         if (bp2 != NULL) {
  138                 bp2->bio_parent = bp;
  139                 bp2->bio_cmd = bp->bio_cmd;
  140                 bp2->bio_length = bp->bio_length;
  141                 bp2->bio_offset = bp->bio_offset;
  142                 bp2->bio_data = bp->bio_data;
  143                 bp2->bio_attribute = bp->bio_attribute;
  144                 bp->bio_children++;
  145         }
  146         return(bp2);
  147 }
  148 
  149 void
  150 g_io_init()
  151 {
  152 
  153         g_bioq_init(&g_bio_run_down);
  154         g_bioq_init(&g_bio_run_up);
  155         g_bioq_init(&g_bio_run_task);
  156         biozone = uma_zcreate("g_bio", sizeof (struct bio),
  157             NULL, NULL,
  158             NULL, NULL,
  159             0, 0);
  160 }
  161 
  162 int
  163 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
  164 {
  165         struct bio *bp;
  166         int error;
  167 
  168         g_trace(G_T_BIO, "bio_getattr(%s)", attr);
  169         bp = g_new_bio();
  170         bp->bio_cmd = BIO_GETATTR;
  171         bp->bio_done = NULL;
  172         bp->bio_attribute = attr;
  173         bp->bio_length = *len;
  174         bp->bio_data = ptr;
  175         g_io_request(bp, cp);
  176         error = biowait(bp, "ggetattr");
  177         *len = bp->bio_completed;
  178         g_destroy_bio(bp);
  179         return (error);
  180 }
  181 
  182 static int
  183 g_io_check(struct bio *bp)
  184 {
  185         struct g_consumer *cp;
  186         struct g_provider *pp;
  187 
  188         cp = bp->bio_from;
  189         pp = bp->bio_to;
  190 
  191         /* Fail if access counters dont allow the operation */
  192         switch(bp->bio_cmd) {
  193         case BIO_READ:
  194         case BIO_GETATTR:
  195                 if (cp->acr == 0)
  196                         return (EPERM);
  197                 break;
  198         case BIO_WRITE:
  199         case BIO_DELETE:
  200                 if (cp->acw == 0)
  201                         return (EPERM);
  202                 break;
  203         default:
  204                 return (EPERM);
  205         }
  206         /* if provider is marked for error, don't disturb. */
  207         if (pp->error)
  208                 return (pp->error);
  209 
  210         switch(bp->bio_cmd) {
  211         case BIO_READ:
  212         case BIO_WRITE:
  213         case BIO_DELETE:
  214                 /* Zero sectorsize is a probably lack of media */
  215                 if (pp->sectorsize == 0)
  216                         return (ENXIO);
  217                 /* Reject I/O not on sector boundary */
  218                 if (bp->bio_offset % pp->sectorsize)
  219                         return (EINVAL);
  220                 /* Reject I/O not integral sector long */
  221                 if (bp->bio_length % pp->sectorsize)
  222                         return (EINVAL);
  223                 /* Reject requests before or past the end of media. */
  224                 if (bp->bio_offset < 0)
  225                         return (EIO);
  226                 if (bp->bio_offset > pp->mediasize)
  227                         return (EIO);
  228                 break;
  229         default:
  230                 break;
  231         }
  232         return (0);
  233 }
  234 
  235 void
  236 g_io_request(struct bio *bp, struct g_consumer *cp)
  237 {
  238         struct g_provider *pp;
  239 
  240         KASSERT(cp != NULL, ("NULL cp in g_io_request"));
  241         KASSERT(bp != NULL, ("NULL bp in g_io_request"));
  242         KASSERT(bp->bio_data != NULL, ("NULL bp->data in g_io_request"));
  243         pp = cp->provider;
  244         KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
  245 
  246         bp->bio_from = cp;
  247         bp->bio_to = pp;
  248         bp->bio_error = 0;
  249         bp->bio_completed = 0;
  250 
  251         if (g_collectstats) {
  252                 devstat_start_transaction_bio(cp->stat, bp);
  253                 devstat_start_transaction_bio(pp->stat, bp);
  254         }
  255         cp->nstart++;
  256         pp->nstart++;
  257 
  258         /* Pass it on down. */
  259         g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
  260             bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
  261         g_bioq_enqueue_tail(bp, &g_bio_run_down);
  262         wakeup(&g_wait_down);
  263 }
  264 
  265 void
  266 g_io_deliver(struct bio *bp, int error)
  267 {
  268         struct g_consumer *cp;
  269         struct g_provider *pp;
  270 
  271         KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
  272         pp = bp->bio_to;
  273         KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver"));
  274         cp = bp->bio_from;
  275         if (cp == NULL) {
  276                 bp->bio_error = error;
  277                 bp->bio_done(bp);
  278                 return;
  279         }
  280         KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver"));
  281         KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
  282 
  283         g_trace(G_T_BIO,
  284 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
  285             bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error,
  286             (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
  287 
  288         bp->bio_bcount = bp->bio_length;
  289         if (g_collectstats) {
  290                 bp->bio_resid = bp->bio_bcount - bp->bio_completed;
  291                 devstat_end_transaction_bio(cp->stat, bp);
  292                 devstat_end_transaction_bio(pp->stat, bp);
  293         }
  294         cp->nend++;
  295         pp->nend++;
  296 
  297         if (error == ENOMEM) {
  298                 if (bootverbose)
  299                         printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
  300                 g_io_request(bp, cp);
  301                 pace++;
  302                 return;
  303         }
  304         bp->bio_error = error;
  305         g_bioq_enqueue_tail(bp, &g_bio_run_up);
  306         wakeup(&g_wait_up);
  307 }
  308 
  309 void
  310 g_io_schedule_down(struct thread *tp __unused)
  311 {
  312         struct bio *bp;
  313         off_t excess;
  314         int error;
  315         struct mtx mymutex;
  316  
  317         bzero(&mymutex, sizeof mymutex);
  318         mtx_init(&mymutex, "g_xdown", NULL, MTX_DEF);
  319 
  320         for(;;) {
  321                 g_bioq_lock(&g_bio_run_down);
  322                 bp = g_bioq_first(&g_bio_run_down);
  323                 if (bp == NULL) {
  324                         msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock,
  325                             PRIBIO | PDROP, "-", hz/10);
  326                         continue;
  327                 }
  328                 g_bioq_unlock(&g_bio_run_down);
  329                 if (pace > 0) {
  330                         msleep(&error, NULL, PRIBIO, "g_down", hz/10);
  331                         pace--;
  332                 }
  333                 error = g_io_check(bp);
  334                 if (error) {
  335                         g_io_deliver(bp, error);
  336                         continue;
  337                 }
  338                 switch (bp->bio_cmd) {
  339                 case BIO_READ:
  340                 case BIO_WRITE:
  341                 case BIO_DELETE:
  342                         /* Truncate requests to the end of providers media. */
  343                         excess = bp->bio_offset + bp->bio_length;
  344                         if (excess > bp->bio_to->mediasize) {
  345                                 excess -= bp->bio_to->mediasize;
  346                                 bp->bio_length -= excess;
  347                         }
  348                         /* Deliver zero length transfers right here. */
  349                         if (bp->bio_length == 0) {
  350                                 g_io_deliver(bp, 0);
  351                                 continue;
  352                         }
  353                         break;
  354                 default:
  355                         break;
  356                 }
  357                 mtx_lock(&mymutex);
  358                 bp->bio_to->geom->start(bp);
  359                 mtx_unlock(&mymutex);
  360         }
  361 }
  362 
  363 void
  364 bio_taskqueue(struct bio *bp, bio_task_t *func, void *arg)
  365 {
  366         bp->bio_task = func;
  367         bp->bio_task_arg = arg;
  368         /*
  369          * The taskqueue is actually just a second queue off the "up"
  370          * queue, so we use the same lock.
  371          */
  372         g_bioq_lock(&g_bio_run_up);
  373         TAILQ_INSERT_TAIL(&g_bio_run_task.bio_queue, bp, bio_queue);
  374         g_bio_run_task.bio_queue_length++;
  375         wakeup(&g_wait_up);
  376         g_bioq_unlock(&g_bio_run_up);
  377 }
  378 
  379 
  380 void
  381 g_io_schedule_up(struct thread *tp __unused)
  382 {
  383         struct bio *bp;
  384         struct mtx mymutex;
  385  
  386         bzero(&mymutex, sizeof mymutex);
  387         mtx_init(&mymutex, "g_xup", NULL, MTX_DEF);
  388         for(;;) {
  389                 g_bioq_lock(&g_bio_run_up);
  390                 bp = g_bioq_first(&g_bio_run_task);
  391                 if (bp != NULL) {
  392                         g_bioq_unlock(&g_bio_run_up);
  393                         mtx_lock(&mymutex);
  394                         bp->bio_task(bp->bio_task_arg);
  395                         mtx_unlock(&mymutex);
  396                         continue;
  397                 }
  398                 bp = g_bioq_first(&g_bio_run_up);
  399                 if (bp != NULL) {
  400                         g_bioq_unlock(&g_bio_run_up);
  401                         mtx_lock(&mymutex);
  402                         biodone(bp);
  403                         mtx_unlock(&mymutex);
  404                         continue;
  405                 }
  406                 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock,
  407                     PRIBIO | PDROP, "-", hz/10);
  408         }
  409 }
  410 
  411 void *
  412 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
  413 {
  414         struct bio *bp;
  415         void *ptr;
  416         int errorc;
  417 
  418         KASSERT(length >= 512 && length <= DFLTPHYS,
  419                 ("g_read_data(): invalid length %jd", (intmax_t)length));
  420 
  421         bp = g_new_bio();
  422         bp->bio_cmd = BIO_READ;
  423         bp->bio_done = NULL;
  424         bp->bio_offset = offset;
  425         bp->bio_length = length;
  426         ptr = g_malloc(length, M_WAITOK);
  427         bp->bio_data = ptr;
  428         g_io_request(bp, cp);
  429         errorc = biowait(bp, "gread");
  430         if (error != NULL)
  431                 *error = errorc;
  432         g_destroy_bio(bp);
  433         if (errorc) {
  434                 g_free(ptr);
  435                 ptr = NULL;
  436         }
  437         return (ptr);
  438 }
  439 
  440 int
  441 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
  442 {
  443         struct bio *bp;
  444         int error;
  445 
  446         KASSERT(length >= 512 && length <= DFLTPHYS,
  447                 ("g_write_data(): invalid length %jd", (intmax_t)length));
  448 
  449         bp = g_new_bio();
  450         bp->bio_cmd = BIO_WRITE;
  451         bp->bio_done = NULL;
  452         bp->bio_offset = offset;
  453         bp->bio_length = length;
  454         bp->bio_data = ptr;
  455         g_io_request(bp, cp);
  456         error = biowait(bp, "gwrite");
  457         g_destroy_bio(bp);
  458         return (error);
  459 }
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FreeBSD/Linux Kernel Cross Reference sys/geom/geom_io.c

FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_io.c
