The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_disk.c

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    1 /*      $NetBSD: subr_disk.c,v 1.83.2.1 2010/11/21 21:52:04 riz Exp $   */
    2 
    3 /*-
    4  * Copyright (c) 1996, 1997, 1999, 2000 The NetBSD Foundation, Inc.
    5  * All rights reserved.
    6  *
    7  * This code is derived from software contributed to The NetBSD Foundation
    8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
    9  * NASA Ames Research Center.
   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. All advertising materials mentioning features or use of this software
   20  *    must display the following acknowledgement:
   21  *      This product includes software developed by the NetBSD
   22  *      Foundation, Inc. and its contributors.
   23  * 4. Neither the name of The NetBSD Foundation nor the names of its
   24  *    contributors may be used to endorse or promote products derived
   25  *    from this software without specific prior written permission.
   26  *
   27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   37  * POSSIBILITY OF SUCH DAMAGE.
   38  */
   39 
   40 /*
   41  * Copyright (c) 1982, 1986, 1988, 1993
   42  *      The Regents of the University of California.  All rights reserved.
   43  * (c) UNIX System Laboratories, Inc.
   44  * All or some portions of this file are derived from material licensed
   45  * to the University of California by American Telephone and Telegraph
   46  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   47  * the permission of UNIX System Laboratories, Inc.
   48  *
   49  * Redistribution and use in source and binary forms, with or without
   50  * modification, are permitted provided that the following conditions
   51  * are met:
   52  * 1. Redistributions of source code must retain the above copyright
   53  *    notice, this list of conditions and the following disclaimer.
   54  * 2. Redistributions in binary form must reproduce the above copyright
   55  *    notice, this list of conditions and the following disclaimer in the
   56  *    documentation and/or other materials provided with the distribution.
   57  * 3. Neither the name of the University nor the names of its contributors
   58  *    may be used to endorse or promote products derived from this software
   59  *    without specific prior written permission.
   60  *
   61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   71  * SUCH DAMAGE.
   72  *
   73  *      @(#)ufs_disksubr.c      8.5 (Berkeley) 1/21/94
   74  */
   75 
   76 #include <sys/cdefs.h>
   77 __KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.83.2.1 2010/11/21 21:52:04 riz Exp $");
   78 
   79 #include <sys/param.h>
   80 #include <sys/kernel.h>
   81 #include <sys/malloc.h>
   82 #include <sys/buf.h>
   83 #include <sys/syslog.h>
   84 #include <sys/disklabel.h>
   85 #include <sys/disk.h>
   86 #include <sys/sysctl.h>
   87 #include <lib/libkern/libkern.h>
   88 
   89 /*
   90  * Compute checksum for disk label.
   91  */
   92 u_int
   93 dkcksum(struct disklabel *lp)
   94 {
   95         u_short *start, *end;
   96         u_short sum = 0;
   97 
   98         start = (u_short *)lp;
   99         end = (u_short *)&lp->d_partitions[lp->d_npartitions];
  100         while (start < end)
  101                 sum ^= *start++;
  102         return (sum);
  103 }
  104 
  105 /*
  106  * Disk error is the preface to plaintive error messages
  107  * about failing disk transfers.  It prints messages of the form
  108 
  109 hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)
  110 
  111  * if the offset of the error in the transfer and a disk label
  112  * are both available.  blkdone should be -1 if the position of the error
  113  * is unknown; the disklabel pointer may be null from drivers that have not
  114  * been converted to use them.  The message is printed with printf
  115  * if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
  116  * The message should be completed (with at least a newline) with printf
  117  * or addlog, respectively.  There is no trailing space.
  118  */
  119 #ifndef PRIdaddr
  120 #define PRIdaddr PRId64
  121 #endif
  122 void
  123 diskerr(const struct buf *bp, const char *dname, const char *what, int pri,
  124     int blkdone, const struct disklabel *lp)
  125 {
  126         int unit = DISKUNIT(bp->b_dev), part = DISKPART(bp->b_dev);
  127         void (*pr)(const char *, ...);
  128         char partname = 'a' + part;
  129         daddr_t sn;
  130 
  131         if (/*CONSTCOND*/0)
  132                 /* Compiler will error this is the format is wrong... */
  133                 printf("%" PRIdaddr, bp->b_blkno);
  134 
  135         if (pri != LOG_PRINTF) {
  136                 static const char fmt[] = "";
  137                 log(pri, fmt);
  138                 pr = addlog;
  139         } else
  140                 pr = printf;
  141         (*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what,
  142             bp->b_flags & B_READ ? "read" : "writ");
  143         sn = bp->b_blkno;
  144         if (bp->b_bcount <= DEV_BSIZE)
  145                 (*pr)("%" PRIdaddr, sn);
  146         else {
  147                 if (blkdone >= 0) {
  148                         sn += blkdone;
  149                         (*pr)("%" PRIdaddr " of ", sn);
  150                 }
  151                 (*pr)("%" PRIdaddr "-%" PRIdaddr "", bp->b_blkno,
  152                     bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
  153         }
  154         if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) {
  155                 sn += lp->d_partitions[part].p_offset;
  156                 (*pr)(" (%s%d bn %" PRIdaddr "; cn %" PRIdaddr "",
  157                     dname, unit, sn, sn / lp->d_secpercyl);
  158                 sn %= lp->d_secpercyl;
  159                 (*pr)(" tn %" PRIdaddr " sn %" PRIdaddr ")",
  160                     sn / lp->d_nsectors, sn % lp->d_nsectors);
  161         }
  162 }
  163 
  164 /*
  165  * Searches the iostatlist for the disk corresponding to the
  166  * name provided.
  167  */
  168 struct disk *
  169 disk_find(const char *name)
  170 {
  171         struct io_stats *stat;
  172 
  173         stat = iostat_find(name);
  174 
  175         if ((stat != NULL) && (stat->io_type == IOSTAT_DISK))
  176                 return stat->io_parent;
  177 
  178         return (NULL);
  179 }
  180 
  181 static void
  182 disk_init0(struct disk *diskp)
  183 {
  184 
  185         /*
  186          * Initialize the wedge-related locks and other fields.
  187          */
  188         lockinit(&diskp->dk_rawlock, PRIBIO, "dkrawlk", 0, 0);
  189         lockinit(&diskp->dk_openlock, PRIBIO, "dkoplk", 0, 0);
  190         LIST_INIT(&diskp->dk_wedges);
  191         diskp->dk_nwedges = 0;
  192         diskp->dk_labelsector = LABELSECTOR;
  193         disk_blocksize(diskp, DEV_BSIZE);
  194 }
  195 
  196 static void
  197 disk_attach0(struct disk *diskp)
  198 {
  199 
  200         /*
  201          * Allocate and initialize the disklabel structures.  Note that
  202          * it's not safe to sleep here, since we're probably going to be
  203          * called during autoconfiguration.
  204          */
  205         diskp->dk_label = malloc(sizeof(struct disklabel), M_DEVBUF, M_NOWAIT);
  206         diskp->dk_cpulabel = malloc(sizeof(struct cpu_disklabel), M_DEVBUF,
  207             M_NOWAIT);
  208         if ((diskp->dk_label == NULL) || (diskp->dk_cpulabel == NULL))
  209                 panic("disk_attach: can't allocate storage for disklabel");
  210 
  211         memset(diskp->dk_label, 0, sizeof(struct disklabel));
  212         memset(diskp->dk_cpulabel, 0, sizeof(struct cpu_disklabel));
  213 
  214         /*
  215          * Set up the stats collection.
  216          */
  217         diskp->dk_stats = iostat_alloc(IOSTAT_DISK, diskp, diskp->dk_name);
  218 }
  219 
  220 static void
  221 disk_detach0(struct disk *diskp)
  222 {
  223 
  224         /*
  225          * Remove from the drivelist.
  226          */
  227         iostat_free(diskp->dk_stats);
  228 
  229         /*
  230          * Release the disk-info dictionary.
  231          */
  232         if (diskp->dk_info) {
  233                 prop_object_release(diskp->dk_info);
  234                 diskp->dk_info = NULL;
  235         }
  236 
  237         /*
  238          * Free the space used by the disklabel structures.
  239          */
  240         free(diskp->dk_label, M_DEVBUF);
  241         free(diskp->dk_cpulabel, M_DEVBUF);
  242 }
  243 
  244 /*
  245  * Attach a disk.
  246  */
  247 void
  248 disk_attach(struct disk *diskp)
  249 {
  250 
  251         disk_init0(diskp);
  252         disk_attach0(diskp);
  253 }
  254 
  255 /*
  256  * Detach a disk.
  257  */
  258 void
  259 disk_detach(struct disk *diskp)
  260 {
  261 
  262         (void) lockmgr(&diskp->dk_openlock, LK_DRAIN, NULL);
  263         disk_detach0(diskp);
  264 }
  265 
  266 /*
  267  * Initialize a pseudo disk.
  268  */
  269 void
  270 pseudo_disk_init(struct disk *diskp)
  271 {
  272 
  273         disk_init0(diskp);
  274 }
  275 
  276 /*
  277  * Attach a pseudo disk.
  278  */
  279 void
  280 pseudo_disk_attach(struct disk *diskp)
  281 {
  282 
  283         disk_attach0(diskp);
  284 }
  285 
  286 /*
  287  * Detach a pseudo disk.
  288  */
  289 void
  290 pseudo_disk_detach(struct disk *diskp)
  291 {
  292 
  293         disk_detach0(diskp);
  294 }
  295 
  296 /*
  297  * Mark the disk as busy for metrics collection.
  298  */
  299 void
  300 disk_busy(struct disk *diskp)
  301 {
  302 
  303         iostat_busy(diskp->dk_stats);
  304 }
  305 
  306 /*
  307  * Finished disk operations, gather metrics.
  308  */
  309 void
  310 disk_unbusy(struct disk *diskp, long bcount, int read)
  311 {
  312 
  313         iostat_unbusy(diskp->dk_stats, bcount, read);
  314 }
  315 
  316 /*
  317  * Set the physical blocksize of a disk, in bytes.
  318  * Only necessary if blocksize != DEV_BSIZE.
  319  */
  320 void
  321 disk_blocksize(struct disk *diskp, int blocksize)
  322 {
  323 
  324         diskp->dk_blkshift = DK_BSIZE2BLKSHIFT(blocksize);
  325         diskp->dk_byteshift = DK_BSIZE2BYTESHIFT(blocksize);
  326 }
  327 
  328 /*
  329  * Bounds checking against the media size, used for the raw partition.
  330  * The sector size passed in should currently always be DEV_BSIZE,
  331  * and the media size the size of the device in DEV_BSIZE sectors.
  332  */
  333 int
  334 bounds_check_with_mediasize(struct buf *bp, int secsize, uint64_t mediasize)
  335 {
  336         int64_t sz;
  337 
  338         sz = howmany(bp->b_bcount, secsize);
  339 
  340         if (bp->b_blkno + sz > mediasize) {
  341                 sz = mediasize - bp->b_blkno;
  342                 if (sz == 0) {
  343                         /* If exactly at end of disk, return EOF. */
  344                         bp->b_resid = bp->b_bcount;
  345                         goto done;
  346                 }
  347                 if (sz < 0) {
  348                         /* If past end of disk, return EINVAL. */
  349                         bp->b_error = EINVAL;
  350                         goto bad;
  351                 }
  352                 /* Otherwise, truncate request. */
  353                 bp->b_bcount = sz << DEV_BSHIFT;
  354         }
  355 
  356         return 1;
  357 
  358 bad:
  359         bp->b_flags |= B_ERROR;
  360 done:
  361         return 0;
  362 }
  363 
  364 /*
  365  * Determine the size of the transfer, and make sure it is
  366  * within the boundaries of the partition. Adjust transfer
  367  * if needed, and signal errors or early completion.
  368  */
  369 int
  370 bounds_check_with_label(struct disk *dk, struct buf *bp, int wlabel)
  371 {
  372         struct disklabel *lp = dk->dk_label;
  373         struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
  374         uint64_t p_size, p_offset, labelsector;
  375         int64_t sz;
  376 
  377         /* Protect against division by zero. XXX: Should never happen?!?! */
  378         if (lp->d_secpercyl == 0) {
  379                 bp->b_error = EINVAL;
  380                 goto bad;
  381         }
  382 
  383         p_size = (uint64_t)p->p_size << dk->dk_blkshift;
  384         p_offset = (uint64_t)p->p_offset << dk->dk_blkshift;
  385 #if RAW_PART == 3
  386         labelsector = lp->d_partitions[2].p_offset;
  387 #else
  388         labelsector = lp->d_partitions[RAW_PART].p_offset;
  389 #endif
  390         labelsector = (labelsector + dk->dk_labelsector) << dk->dk_blkshift;
  391 
  392         sz = howmany(bp->b_bcount, DEV_BSIZE);
  393         if ((bp->b_blkno + sz) > p_size) {
  394                 sz = p_size - bp->b_blkno;
  395                 if (sz == 0) {
  396                         /* If exactly at end of disk, return EOF. */
  397                         bp->b_resid = bp->b_bcount;
  398                         return (0);
  399                 }
  400                 if (sz < 0) {
  401                         /* If past end of disk, return EINVAL. */
  402                         bp->b_error = EINVAL;
  403                         goto bad;
  404                 }
  405                 /* Otherwise, truncate request. */
  406                 bp->b_bcount = sz << DEV_BSHIFT;
  407         }
  408 
  409         /* Overwriting disk label? */
  410         if (bp->b_blkno + p_offset <= labelsector &&
  411             bp->b_blkno + p_offset + sz > labelsector &&
  412             (bp->b_flags & B_READ) == 0 && !wlabel) {
  413                 bp->b_error = EROFS;
  414                 goto bad;
  415         }
  416 
  417         /* calculate cylinder for disksort to order transfers with */
  418         bp->b_cylinder = (bp->b_blkno + p->p_offset) /
  419             (lp->d_secsize / DEV_BSIZE) / lp->d_secpercyl;
  420         return (1);
  421 
  422 bad:
  423         bp->b_flags |= B_ERROR;
  424         return (-1);
  425 }
  426 
  427 /*
  428  * disk_ioctl --
  429  *      Generic disk ioctl handling.
  430  */
  431 int
  432 disk_ioctl(struct disk *diskp, u_long cmd, caddr_t data, int flag,
  433            struct lwp *l)
  434 {
  435         int error;
  436 
  437         switch (cmd) {
  438         case DIOCGDISKINFO:
  439             {
  440                 struct plistref *pref = (struct plistref *) data;
  441 
  442                 if (diskp->dk_info == NULL)
  443                         error = ENOTSUP;
  444                 else
  445                         error = prop_dictionary_copyout_ioctl(pref, cmd,
  446                                                         diskp->dk_info);
  447                 break;
  448             }
  449 
  450         default:
  451                 error = EPASSTHROUGH;
  452         }
  453 
  454         return (error);
  455 }

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