The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/fs/msdosfs/msdosfs_vfsops.c

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    1 /* $FreeBSD: releng/5.0/sys/fs/msdosfs/msdosfs_vfsops.c 105655 2002-10-21 20:52:51Z jhb $ */
    2 /*      $NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws Exp $   */
    3 
    4 /*-
    5  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
    6  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
    7  * All rights reserved.
    8  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 3. All advertising materials mentioning features or use of this software
   19  *    must display the following acknowledgement:
   20  *      This product includes software developed by TooLs GmbH.
   21  * 4. The name of TooLs GmbH may not be used to endorse or promote products
   22  *    derived from this software without specific prior written permission.
   23  *
   24  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
   25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   27  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   29  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
   30  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   31  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
   32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   33  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   34  */
   35 /*
   36  * Written by Paul Popelka (paulp@uts.amdahl.com)
   37  *
   38  * You can do anything you want with this software, just don't say you wrote
   39  * it, and don't remove this notice.
   40  *
   41  * This software is provided "as is".
   42  *
   43  * The author supplies this software to be publicly redistributed on the
   44  * understanding that the author is not responsible for the correct
   45  * functioning of this software in any circumstances and is not liable for
   46  * any damages caused by this software.
   47  *
   48  * October 1992
   49  */
   50 
   51 #include <sys/param.h>
   52 #include <sys/systm.h>
   53 #include <sys/conf.h>
   54 #include <sys/namei.h>
   55 #include <sys/proc.h>
   56 #include <sys/kernel.h>
   57 #include <sys/vnode.h>
   58 #include <sys/mount.h>
   59 #include <sys/bio.h>
   60 #include <sys/buf.h>
   61 #include <sys/fcntl.h>
   62 #include <sys/malloc.h>
   63 #include <sys/stat.h>                           /* defines ALLPERMS */
   64 #include <sys/mutex.h>
   65 
   66 #include <fs/msdosfs/bpb.h>
   67 #include <fs/msdosfs/bootsect.h>
   68 #include <fs/msdosfs/direntry.h>
   69 #include <fs/msdosfs/denode.h>
   70 #include <fs/msdosfs/msdosfsmount.h>
   71 #include <fs/msdosfs/fat.h>
   72 
   73 #define MSDOSFS_DFLTBSIZE       4096
   74 
   75 #if 1 /*def PC98*/
   76 /*
   77  * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
   78  *       garbage or a random value :-{
   79  *       If you want to use that broken-signatured media, define the
   80  *       following symbol even though PC/AT.
   81  *       (ex. mount PC-98 DOS formatted FD on PC/AT)
   82  */
   83 #define MSDOSFS_NOCHECKSIG
   84 #endif
   85 
   86 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
   87 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
   88 
   89 static int      update_mp(struct mount *mp, struct msdosfs_args *argp);
   90 static int      mountmsdosfs(struct vnode *devvp, struct mount *mp,
   91                     struct thread *td, struct msdosfs_args *argp);
   92 static vfs_fhtovp_t     msdosfs_fhtovp;
   93 static vfs_mount_t      msdosfs_mount;
   94 static vfs_root_t       msdosfs_root;
   95 static vfs_statfs_t     msdosfs_statfs;
   96 static vfs_sync_t       msdosfs_sync;
   97 static vfs_unmount_t    msdosfs_unmount;
   98 static vfs_vptofh_t     msdosfs_vptofh;
   99 
  100 static int
  101 update_mp(mp, argp)
  102         struct mount *mp;
  103         struct msdosfs_args *argp;
  104 {
  105         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  106         int error;
  107 
  108         pmp->pm_gid = argp->gid;
  109         pmp->pm_uid = argp->uid;
  110         pmp->pm_mask = argp->mask & ALLPERMS;
  111         pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
  112         if (pmp->pm_flags & MSDOSFSMNT_U2WTABLE) {
  113                 bcopy(argp->u2w, pmp->pm_u2w, sizeof(pmp->pm_u2w));
  114                 bcopy(argp->d2u, pmp->pm_d2u, sizeof(pmp->pm_d2u));
  115                 bcopy(argp->u2d, pmp->pm_u2d, sizeof(pmp->pm_u2d));
  116         }
  117         if (pmp->pm_flags & MSDOSFSMNT_ULTABLE) {
  118                 bcopy(argp->ul, pmp->pm_ul, sizeof(pmp->pm_ul));
  119                 bcopy(argp->lu, pmp->pm_lu, sizeof(pmp->pm_lu));
  120         }
  121 
  122         if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
  123                 pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
  124         else if (!(pmp->pm_flags &
  125             (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
  126                 struct vnode *rootvp;
  127 
  128                 /*
  129                  * Try to divine whether to support Win'95 long filenames
  130                  */
  131                 if (FAT32(pmp))
  132                         pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
  133                 else {
  134                         if ((error = msdosfs_root(mp, &rootvp)) != 0)
  135                                 return error;
  136                         pmp->pm_flags |= findwin95(VTODE(rootvp))
  137                                 ? MSDOSFSMNT_LONGNAME
  138                                         : MSDOSFSMNT_SHORTNAME;
  139                         vput(rootvp);
  140                 }
  141         }
  142         return 0;
  143 }
  144 
  145 /*
  146  * mp - path - addr in user space of mount point (ie /usr or whatever)
  147  * data - addr in user space of mount params including the name of the block
  148  * special file to treat as a filesystem.
  149  */
  150 static int
  151 msdosfs_mount(mp, path, data, ndp, td)
  152         struct mount *mp;
  153         char *path;
  154         caddr_t data;
  155         struct nameidata *ndp;
  156         struct thread *td;
  157 {
  158         struct vnode *devvp;      /* vnode for blk device to mount */
  159         struct msdosfs_args args; /* will hold data from mount request */
  160         /* msdosfs specific mount control block */
  161         struct msdosfsmount *pmp = NULL;
  162         size_t size;
  163         int error, flags;
  164         mode_t accessmode;
  165 
  166         error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
  167         if (error)
  168                 return (error);
  169         if (args.magic != MSDOSFS_ARGSMAGIC)
  170                 args.flags = 0;
  171         /*
  172          * If updating, check whether changing from read-only to
  173          * read/write; if there is no device name, that's all we do.
  174          */
  175         if (mp->mnt_flag & MNT_UPDATE) {
  176                 pmp = VFSTOMSDOSFS(mp);
  177                 error = 0;
  178                 if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
  179                         flags = WRITECLOSE;
  180                         if (mp->mnt_flag & MNT_FORCE)
  181                                 flags |= FORCECLOSE;
  182                         error = vflush(mp, 0, flags);
  183                 }
  184                 if (!error && (mp->mnt_flag & MNT_RELOAD))
  185                         /* not yet implemented */
  186                         error = EOPNOTSUPP;
  187                 if (error)
  188                         return (error);
  189                 if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
  190                         /*
  191                          * If upgrade to read-write by non-root, then verify
  192                          * that user has necessary permissions on the device.
  193                          */
  194                         if (suser(td)) {
  195                                 devvp = pmp->pm_devvp;
  196                                 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
  197                                 error = VOP_ACCESS(devvp, VREAD | VWRITE,
  198                                                    td->td_ucred, td);
  199                                 if (error) {
  200                                         VOP_UNLOCK(devvp, 0, td);
  201                                         return (error);
  202                                 }
  203                                 VOP_UNLOCK(devvp, 0, td);
  204                         }
  205                         pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
  206                 }
  207                 if (args.fspec == 0) {
  208 #ifdef  __notyet__      /* doesn't work correctly with current mountd   XXX */
  209                         if (args.flags & MSDOSFSMNT_MNTOPT) {
  210                                 pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
  211                                 pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
  212                                 if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
  213                                         pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
  214                         }
  215 #endif
  216                         /*
  217                          * Process export requests.
  218                          */
  219                         return (vfs_export(mp, &args.export));
  220                 }
  221         }
  222         /*
  223          * Not an update, or updating the name: look up the name
  224          * and verify that it refers to a sensible block device.
  225          */
  226         NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, td);
  227         error = namei(ndp);
  228         if (error)
  229                 return (error);
  230         devvp = ndp->ni_vp;
  231         NDFREE(ndp, NDF_ONLY_PNBUF);
  232 
  233         if (!vn_isdisk(devvp, &error)) {
  234                 vrele(devvp);
  235                 return (error);
  236         }
  237         /*
  238          * If mount by non-root, then verify that user has necessary
  239          * permissions on the device.
  240          */
  241         if (suser(td)) {
  242                 accessmode = VREAD;
  243                 if ((mp->mnt_flag & MNT_RDONLY) == 0)
  244                         accessmode |= VWRITE;
  245                 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
  246                 error = VOP_ACCESS(devvp, accessmode, td->td_ucred, td);
  247                 if (error) {
  248                         vput(devvp);
  249                         return (error);
  250                 }
  251                 VOP_UNLOCK(devvp, 0, td);
  252         }
  253         if ((mp->mnt_flag & MNT_UPDATE) == 0) {
  254                 error = mountmsdosfs(devvp, mp, td, &args);
  255 #ifdef MSDOSFS_DEBUG            /* only needed for the printf below */
  256                 pmp = VFSTOMSDOSFS(mp);
  257 #endif
  258         } else {
  259                 if (devvp != pmp->pm_devvp)
  260                         error = EINVAL; /* XXX needs translation */
  261                 else
  262                         vrele(devvp);
  263         }
  264         if (error) {
  265                 vrele(devvp);
  266                 return (error);
  267         }
  268 
  269         error = update_mp(mp, &args);
  270         if (error) {
  271                 msdosfs_unmount(mp, MNT_FORCE, td);
  272                 return error;
  273         }
  274         (void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
  275             &size);
  276         bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
  277         (void) msdosfs_statfs(mp, &mp->mnt_stat, td);
  278 #ifdef MSDOSFS_DEBUG
  279         printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
  280 #endif
  281         return (0);
  282 }
  283 
  284 static int
  285 mountmsdosfs(devvp, mp, td, argp)
  286         struct vnode *devvp;
  287         struct mount *mp;
  288         struct thread *td;
  289         struct msdosfs_args *argp;
  290 {
  291         struct msdosfsmount *pmp;
  292         struct buf *bp;
  293         dev_t dev = devvp->v_rdev;
  294         union bootsector *bsp;
  295         struct byte_bpb33 *b33;
  296         struct byte_bpb50 *b50;
  297         struct byte_bpb710 *b710;
  298         u_int8_t SecPerClust;
  299         u_long clusters;
  300         int     ronly, error;
  301 
  302         /*
  303          * Disallow multiple mounts of the same device.
  304          * Disallow mounting of a device that is currently in use
  305          * (except for root, which might share swap device for miniroot).
  306          * Flush out any old buffers remaining from a previous use.
  307          */
  308         error = vfs_mountedon(devvp);
  309         if (error)
  310                 return (error);
  311         if (vcount(devvp) > 1 && devvp != rootvp)
  312                 return (EBUSY);
  313         vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
  314         error = vinvalbuf(devvp, V_SAVE, td->td_ucred, td, 0, 0);
  315         VOP_UNLOCK(devvp, 0, td);
  316         if (error)
  317                 return (error);
  318 
  319         ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
  320         vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
  321         error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, td);
  322         VOP_UNLOCK(devvp, 0, td);
  323         if (error)
  324                 return (error);
  325 
  326         bp  = NULL; /* both used in error_exit */
  327         pmp = NULL;
  328 
  329         /*
  330          * Read the boot sector of the filesystem, and then check the
  331          * boot signature.  If not a dos boot sector then error out.
  332          *
  333          * NOTE: 2048 is a maximum sector size in current...
  334          */
  335         error = bread(devvp, 0, 2048, NOCRED, &bp);
  336         if (error)
  337                 goto error_exit;
  338         bp->b_flags |= B_AGE;
  339         bsp = (union bootsector *)bp->b_data;
  340         b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
  341         b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
  342         b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
  343 
  344 #ifndef MSDOSFS_NOCHECKSIG
  345         if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
  346             || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
  347                 error = EINVAL;
  348                 goto error_exit;
  349         }
  350 #endif
  351 
  352         pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK | M_ZERO);
  353         pmp->pm_mountp = mp;
  354 
  355         /*
  356          * Compute several useful quantities from the bpb in the
  357          * bootsector.  Copy in the dos 5 variant of the bpb then fix up
  358          * the fields that are different between dos 5 and dos 3.3.
  359          */
  360         SecPerClust = b50->bpbSecPerClust;
  361         pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
  362         pmp->pm_ResSectors = getushort(b50->bpbResSectors);
  363         pmp->pm_FATs = b50->bpbFATs;
  364         pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
  365         pmp->pm_Sectors = getushort(b50->bpbSectors);
  366         pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
  367         pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
  368         pmp->pm_Heads = getushort(b50->bpbHeads);
  369         pmp->pm_Media = b50->bpbMedia;
  370 
  371         /* calculate the ratio of sector size to DEV_BSIZE */
  372         pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
  373 
  374         /* XXX - We should probably check more values here */
  375         if (!pmp->pm_BytesPerSec || !SecPerClust
  376                 || !pmp->pm_Heads || pmp->pm_Heads > 255
  377 #ifdef PC98
  378                 || !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 255) {
  379 #else
  380                 || !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
  381 #endif
  382                 error = EINVAL;
  383                 goto error_exit;
  384         }
  385 
  386         if (pmp->pm_Sectors == 0) {
  387                 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
  388                 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
  389         } else {
  390                 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
  391                 pmp->pm_HugeSectors = pmp->pm_Sectors;
  392         }
  393         if (pmp->pm_HugeSectors > 0xffffffff / 
  394             (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
  395                 /*
  396                  * We cannot deal currently with this size of disk
  397                  * due to fileid limitations (see msdosfs_getattr and
  398                  * msdosfs_readdir)
  399                  */
  400                 error = EINVAL;
  401                 printf("mountmsdosfs(): disk too big, sorry\n");
  402                 goto error_exit;
  403         }
  404 
  405         if (pmp->pm_RootDirEnts == 0) {
  406                 if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
  407                     || bsp->bs710.bsBootSectSig3 != BOOTSIG3
  408                     || pmp->pm_Sectors
  409                     || pmp->pm_FATsecs
  410                     || getushort(b710->bpbFSVers)) {
  411                         error = EINVAL;
  412                         printf("mountmsdosfs(): bad FAT32 filesystem\n");
  413                         goto error_exit;
  414                 }
  415                 pmp->pm_fatmask = FAT32_MASK;
  416                 pmp->pm_fatmult = 4;
  417                 pmp->pm_fatdiv = 1;
  418                 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
  419                 if (getushort(b710->bpbExtFlags) & FATMIRROR)
  420                         pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
  421                 else
  422                         pmp->pm_flags |= MSDOSFS_FATMIRROR;
  423         } else
  424                 pmp->pm_flags |= MSDOSFS_FATMIRROR;
  425 
  426         /*
  427          * Check a few values (could do some more):
  428          * - logical sector size: power of 2, >= block size
  429          * - sectors per cluster: power of 2, >= 1
  430          * - number of sectors:   >= 1, <= size of partition
  431          */
  432         if ( (SecPerClust == 0)
  433           || (SecPerClust & (SecPerClust - 1))
  434           || (pmp->pm_BytesPerSec < DEV_BSIZE)
  435           || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
  436           || (pmp->pm_HugeSectors == 0)
  437         ) {
  438                 error = EINVAL;
  439                 goto error_exit;
  440         }
  441 
  442         pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
  443         pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
  444         pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
  445         SecPerClust         *= pmp->pm_BlkPerSec;
  446 
  447         pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
  448 
  449         if (FAT32(pmp)) {
  450                 pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
  451                 pmp->pm_firstcluster = pmp->pm_fatblk
  452                         + (pmp->pm_FATs * pmp->pm_FATsecs);
  453                 pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
  454         } else {
  455                 pmp->pm_rootdirblk = pmp->pm_fatblk +
  456                         (pmp->pm_FATs * pmp->pm_FATsecs);
  457                 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
  458                                        + DEV_BSIZE - 1)
  459                         / DEV_BSIZE; /* in blocks */
  460                 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
  461         }
  462 
  463         pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
  464             SecPerClust + 1;
  465         pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
  466 
  467         if (pmp->pm_fatmask == 0) {
  468                 if (pmp->pm_maxcluster
  469                     <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
  470                         /*
  471                          * This will usually be a floppy disk. This size makes
  472                          * sure that one fat entry will not be split across
  473                          * multiple blocks.
  474                          */
  475                         pmp->pm_fatmask = FAT12_MASK;
  476                         pmp->pm_fatmult = 3;
  477                         pmp->pm_fatdiv = 2;
  478                 } else {
  479                         pmp->pm_fatmask = FAT16_MASK;
  480                         pmp->pm_fatmult = 2;
  481                         pmp->pm_fatdiv = 1;
  482                 }
  483         }
  484 
  485         clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
  486         if (pmp->pm_maxcluster >= clusters) {
  487                 printf("Warning: number of clusters (%ld) exceeds FAT "
  488                     "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
  489                 pmp->pm_maxcluster = clusters - 1;
  490         }
  491 
  492 
  493         if (FAT12(pmp))
  494                 pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
  495         else
  496                 pmp->pm_fatblocksize = MSDOSFS_DFLTBSIZE;
  497 
  498         pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
  499         pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
  500 
  501         /*
  502          * Compute mask and shift value for isolating cluster relative byte
  503          * offsets and cluster numbers from a file offset.
  504          */
  505         pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
  506         pmp->pm_crbomask = pmp->pm_bpcluster - 1;
  507         pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
  508 
  509         /*
  510          * Check for valid cluster size
  511          * must be a power of 2
  512          */
  513         if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
  514                 error = EINVAL;
  515                 goto error_exit;
  516         }
  517 
  518         /*
  519          * Release the bootsector buffer.
  520          */
  521         brelse(bp);
  522         bp = NULL;
  523 
  524         /*
  525          * Check FSInfo.
  526          */
  527         if (pmp->pm_fsinfo) {
  528                 struct fsinfo *fp;
  529 
  530                 if ((error = bread(devvp, pmp->pm_fsinfo, fsi_size(pmp),
  531                     NOCRED, &bp)) != 0)
  532                         goto error_exit;
  533                 fp = (struct fsinfo *)bp->b_data;
  534                 if (!bcmp(fp->fsisig1, "RRaA", 4)
  535                     && !bcmp(fp->fsisig2, "rrAa", 4)
  536                     && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
  537                     && !bcmp(fp->fsisig4, "\0\0\125\252", 4))
  538                         pmp->pm_nxtfree = getulong(fp->fsinxtfree);
  539                 else
  540                         pmp->pm_fsinfo = 0;
  541                 brelse(bp);
  542                 bp = NULL;
  543         }
  544 
  545         /*
  546          * Check and validate (or perhaps invalidate?) the fsinfo structure?
  547          */
  548         if (pmp->pm_fsinfo && pmp->pm_nxtfree > pmp->pm_maxcluster) {
  549                 printf(
  550                 "Next free cluster in FSInfo (%lu) exceeds maxcluster (%lu)\n",
  551                     pmp->pm_nxtfree, pmp->pm_maxcluster);
  552                 error = EINVAL;
  553                 goto error_exit;
  554         }
  555 
  556         /*
  557          * Allocate memory for the bitmap of allocated clusters, and then
  558          * fill it in.
  559          */
  560         pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
  561                                    / N_INUSEBITS)
  562                                   * sizeof(*pmp->pm_inusemap),
  563                                   M_MSDOSFSFAT, M_WAITOK);
  564 
  565         /*
  566          * fillinusemap() needs pm_devvp.
  567          */
  568         pmp->pm_dev = dev;
  569         pmp->pm_devvp = devvp;
  570 
  571         /*
  572          * Have the inuse map filled in.
  573          */
  574         if ((error = fillinusemap(pmp)) != 0)
  575                 goto error_exit;
  576 
  577         /*
  578          * If they want fat updates to be synchronous then let them suffer
  579          * the performance degradation in exchange for the on disk copy of
  580          * the fat being correct just about all the time.  I suppose this
  581          * would be a good thing to turn on if the kernel is still flakey.
  582          */
  583         if (mp->mnt_flag & MNT_SYNCHRONOUS)
  584                 pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
  585 
  586         /*
  587          * Finish up.
  588          */
  589         if (ronly)
  590                 pmp->pm_flags |= MSDOSFSMNT_RONLY;
  591         else
  592                 pmp->pm_fmod = 1;
  593         mp->mnt_data = (qaddr_t) pmp;
  594         mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
  595         mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
  596         mp->mnt_flag |= MNT_LOCAL;
  597         devvp->v_rdev->si_mountpoint = mp;
  598 
  599         return 0;
  600 
  601 error_exit:
  602         if (bp)
  603                 brelse(bp);
  604         (void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, NOCRED, td);
  605         if (pmp) {
  606                 if (pmp->pm_inusemap)
  607                         free(pmp->pm_inusemap, M_MSDOSFSFAT);
  608                 free(pmp, M_MSDOSFSMNT);
  609                 mp->mnt_data = (qaddr_t)0;
  610         }
  611         return (error);
  612 }
  613 
  614 /*
  615  * Unmount the filesystem described by mp.
  616  */
  617 static int
  618 msdosfs_unmount(mp, mntflags, td)
  619         struct mount *mp;
  620         int mntflags;
  621         struct thread *td;
  622 {
  623         struct msdosfsmount *pmp;
  624         int error, flags;
  625 
  626         flags = 0;
  627         if (mntflags & MNT_FORCE)
  628                 flags |= FORCECLOSE;
  629         error = vflush(mp, 0, flags);
  630         if (error)
  631                 return error;
  632         pmp = VFSTOMSDOSFS(mp);
  633         pmp->pm_devvp->v_rdev->si_mountpoint = NULL;
  634 #ifdef MSDOSFS_DEBUG
  635         {
  636                 struct vnode *vp = pmp->pm_devvp;
  637 
  638                 VI_LOCK(vp);
  639                 printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
  640                 printf("iflag %08lx, usecount %d, writecount %d, holdcnt %ld\n",
  641                     vp->vi_flag, vp->v_usecount, vp->v_writecount,
  642                     vp->v_holdcnt);
  643                 printf("id %lu, mount %p, op %p\n",
  644                     vp->v_id, vp->v_mount, vp->v_op);
  645                 printf("freef %p, freeb %p, mount %p\n",
  646                     TAILQ_NEXT(vp, v_freelist), vp->v_freelist.tqe_prev,
  647                     vp->v_mount);
  648                 printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
  649                     TAILQ_FIRST(&vp->v_cleanblkhd),
  650                     TAILQ_FIRST(&vp->v_dirtyblkhd),
  651                     vp->v_numoutput, vp->v_type);
  652                 printf("union %p, tag %s, data[0] %08x, data[1] %08x\n",
  653                     vp->v_socket, vp->v_tag,
  654                     ((u_int *)vp->v_data)[0],
  655                     ((u_int *)vp->v_data)[1]);
  656                 VI_UNLOCK(vp);
  657         }
  658 #endif
  659         error = VOP_CLOSE(pmp->pm_devvp,
  660                     (pmp->pm_flags&MSDOSFSMNT_RONLY) ? FREAD : FREAD | FWRITE,
  661                     NOCRED, td);
  662         vrele(pmp->pm_devvp);
  663         free(pmp->pm_inusemap, M_MSDOSFSFAT);
  664         free(pmp, M_MSDOSFSMNT);
  665         mp->mnt_data = (qaddr_t)0;
  666         mp->mnt_flag &= ~MNT_LOCAL;
  667         return (error);
  668 }
  669 
  670 static int
  671 msdosfs_root(mp, vpp)
  672         struct mount *mp;
  673         struct vnode **vpp;
  674 {
  675         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  676         struct denode *ndep;
  677         int error;
  678 
  679 #ifdef MSDOSFS_DEBUG
  680         printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
  681 #endif
  682         error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
  683         if (error)
  684                 return (error);
  685         *vpp = DETOV(ndep);
  686         return (0);
  687 }
  688 
  689 static int
  690 msdosfs_statfs(mp, sbp, td)
  691         struct mount *mp;
  692         struct statfs *sbp;
  693         struct thread *td;
  694 {
  695         struct msdosfsmount *pmp;
  696 
  697         pmp = VFSTOMSDOSFS(mp);
  698         sbp->f_bsize = pmp->pm_bpcluster;
  699         sbp->f_iosize = pmp->pm_bpcluster;
  700         sbp->f_blocks = pmp->pm_maxcluster + 1;
  701         sbp->f_bfree = pmp->pm_freeclustercount;
  702         sbp->f_bavail = pmp->pm_freeclustercount;
  703         sbp->f_files = pmp->pm_RootDirEnts;                     /* XXX */
  704         sbp->f_ffree = 0;       /* what to put in here? */
  705         if (sbp != &mp->mnt_stat) {
  706                 sbp->f_type = mp->mnt_vfc->vfc_typenum;
  707                 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
  708                 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
  709         }
  710         strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
  711         return (0);
  712 }
  713 
  714 static int
  715 msdosfs_sync(mp, waitfor, cred, td)
  716         struct mount *mp;
  717         int waitfor;
  718         struct ucred *cred;
  719         struct thread *td;
  720 {
  721         struct vnode *vp, *nvp;
  722         struct denode *dep;
  723         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  724         int error, allerror = 0;
  725 
  726         /*
  727          * If we ever switch to not updating all of the fats all the time,
  728          * this would be the place to update them from the first one.
  729          */
  730         if (pmp->pm_fmod != 0) {
  731                 if (pmp->pm_flags & MSDOSFSMNT_RONLY)
  732                         panic("msdosfs_sync: rofs mod");
  733                 else {
  734                         /* update fats here */
  735                 }
  736         }
  737         /*
  738          * Write back each (modified) denode.
  739          */
  740         mtx_lock(&mntvnode_mtx);
  741 loop:
  742         for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
  743                 /*
  744                  * If the vnode that we are about to sync is no longer
  745                  * associated with this mount point, start over.
  746                  */
  747                 if (vp->v_mount != mp)
  748                         goto loop;
  749                 nvp = TAILQ_NEXT(vp, v_nmntvnodes);
  750 
  751                 mtx_unlock(&mntvnode_mtx);
  752                 VI_LOCK(vp);
  753                 dep = VTODE(vp);
  754                 if (vp->v_type == VNON ||
  755                     ((dep->de_flag &
  756                     (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
  757                     (TAILQ_EMPTY(&vp->v_dirtyblkhd) || waitfor == MNT_LAZY))) {
  758                         VI_UNLOCK(vp);
  759                         mtx_lock(&mntvnode_mtx);
  760                         continue;
  761                 }
  762                 error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
  763                 if (error) {
  764                         mtx_lock(&mntvnode_mtx);
  765                         if (error == ENOENT)
  766                                 goto loop;
  767                         continue;
  768                 }
  769                 error = VOP_FSYNC(vp, cred, waitfor, td);
  770                 if (error)
  771                         allerror = error;
  772                 VOP_UNLOCK(vp, 0, td);
  773                 vrele(vp);
  774                 mtx_lock(&mntvnode_mtx);
  775         }
  776         mtx_unlock(&mntvnode_mtx);
  777 
  778         /*
  779          * Flush filesystem control info.
  780          */
  781         if (waitfor != MNT_LAZY) {
  782                 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY, td);
  783                 error = VOP_FSYNC(pmp->pm_devvp, cred, waitfor, td);
  784                 if (error)
  785                         allerror = error;
  786                 VOP_UNLOCK(pmp->pm_devvp, 0, td);
  787         }
  788         return (allerror);
  789 }
  790 
  791 static int
  792 msdosfs_fhtovp(mp, fhp, vpp)
  793         struct mount *mp;
  794         struct fid *fhp;
  795         struct vnode **vpp;
  796 {
  797         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  798         struct defid *defhp = (struct defid *) fhp;
  799         struct denode *dep;
  800         int error;
  801 
  802         error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
  803         if (error) {
  804                 *vpp = NULLVP;
  805                 return (error);
  806         }
  807         *vpp = DETOV(dep);
  808         return (0);
  809 }
  810 
  811 static int
  812 msdosfs_vptofh(vp, fhp)
  813         struct vnode *vp;
  814         struct fid *fhp;
  815 {
  816         struct denode *dep;
  817         struct defid *defhp;
  818 
  819         dep = VTODE(vp);
  820         defhp = (struct defid *)fhp;
  821         defhp->defid_len = sizeof(struct defid);
  822         defhp->defid_dirclust = dep->de_dirclust;
  823         defhp->defid_dirofs = dep->de_diroffset;
  824         /* defhp->defid_gen = dep->de_gen; */
  825         return (0);
  826 }
  827 
  828 static struct vfsops msdosfs_vfsops = {
  829         msdosfs_mount,
  830         vfs_stdstart,
  831         msdosfs_unmount,
  832         msdosfs_root,
  833         vfs_stdquotactl,
  834         msdosfs_statfs,
  835         msdosfs_sync,
  836         vfs_stdvget,
  837         msdosfs_fhtovp,
  838         vfs_stdcheckexp,
  839         msdosfs_vptofh,
  840         msdosfs_init,
  841         msdosfs_uninit,
  842         vfs_stdextattrctl,
  843 };
  844 
  845 VFS_SET(msdosfs_vfsops, msdosfs, 0);

Cache object: ccf04bf8cbdbed1faac4563e6eb4a77d


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