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 /*      $NetBSD: msdosfs_vfsops.c,v 1.13.2.2 2004/06/27 13:53:13 he Exp $       */
    2 
    3 /*-
    4  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
    5  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
    6  * All rights reserved.
    7  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
    8  *
    9  * Redistribution and use in source and binary forms, with or without
   10  * modification, are permitted provided that the following conditions
   11  * are met:
   12  * 1. Redistributions of source code must retain the above copyright
   13  *    notice, this list of conditions and the following disclaimer.
   14  * 2. Redistributions in binary form must reproduce the above copyright
   15  *    notice, this list of conditions and the following disclaimer in the
   16  *    documentation and/or other materials provided with the distribution.
   17  * 3. All advertising materials mentioning features or use of this software
   18  *    must display the following acknowledgement:
   19  *      This product includes software developed by TooLs GmbH.
   20  * 4. The name of TooLs GmbH may not be used to endorse or promote products
   21  *    derived from this software without specific prior written permission.
   22  *
   23  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
   24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   26  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   28  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
   29  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   30  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
   31  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   32  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   33  */
   34 /*
   35  * Written by Paul Popelka (paulp@uts.amdahl.com)
   36  *
   37  * You can do anything you want with this software, just don't say you wrote
   38  * it, and don't remove this notice.
   39  *
   40  * This software is provided "as is".
   41  *
   42  * The author supplies this software to be publicly redistributed on the
   43  * understanding that the author is not responsible for the correct
   44  * functioning of this software in any circumstances and is not liable for
   45  * any damages caused by this software.
   46  *
   47  * October 1992
   48  */
   49 
   50 #include <sys/cdefs.h>
   51 __KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.13.2.2 2004/06/27 13:53:13 he Exp $");
   52 
   53 #if defined(_KERNEL_OPT)
   54 #include "opt_quota.h"
   55 #include "opt_compat_netbsd.h"
   56 #endif
   57 
   58 #include <sys/param.h>
   59 #include <sys/systm.h>
   60 #include <sys/sysctl.h>
   61 #include <sys/namei.h>
   62 #include <sys/proc.h>
   63 #include <sys/kernel.h>
   64 #include <sys/vnode.h>
   65 #include <miscfs/specfs/specdev.h> /* XXX */    /* defines v_rdev */
   66 #include <sys/mount.h>
   67 #include <sys/buf.h>
   68 #include <sys/file.h>
   69 #include <sys/device.h>
   70 #include <sys/disklabel.h>
   71 #include <sys/ioctl.h>
   72 #include <sys/malloc.h>
   73 #include <sys/dirent.h>
   74 #include <sys/stat.h>
   75 #include <sys/conf.h>
   76 
   77 #include <fs/msdosfs/bpb.h>
   78 #include <fs/msdosfs/bootsect.h>
   79 #include <fs/msdosfs/direntry.h>
   80 #include <fs/msdosfs/denode.h>
   81 #include <fs/msdosfs/msdosfsmount.h>
   82 #include <fs/msdosfs/fat.h>
   83 
   84 int msdosfs_mountroot __P((void));
   85 int msdosfs_mount __P((struct mount *, const char *, void *,
   86     struct nameidata *, struct proc *));
   87 int msdosfs_start __P((struct mount *, int, struct proc *));
   88 int msdosfs_unmount __P((struct mount *, int, struct proc *));
   89 int msdosfs_root __P((struct mount *, struct vnode **));
   90 int msdosfs_quotactl __P((struct mount *, int, uid_t, caddr_t, struct proc *));
   91 int msdosfs_statfs __P((struct mount *, struct statfs *, struct proc *));
   92 int msdosfs_sync __P((struct mount *, int, struct ucred *, struct proc *));
   93 int msdosfs_vget __P((struct mount *, ino_t, struct vnode **));
   94 int msdosfs_fhtovp __P((struct mount *, struct fid *, struct vnode **));
   95 int msdosfs_checkexp __P((struct mount *, struct mbuf *, int *,
   96     struct ucred **));
   97 int msdosfs_vptofh __P((struct vnode *, struct fid *));
   98 
   99 int msdosfs_mountfs __P((struct vnode *, struct mount *, struct proc *,
  100     struct msdosfs_args *));
  101 
  102 static int update_mp __P((struct mount *, struct msdosfs_args *));
  103 
  104 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOS FS mount structure");
  105 MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS fat", "MSDOS FS fat table");
  106 
  107 #define ROOTNAME "root_device"
  108 
  109 extern const struct vnodeopv_desc msdosfs_vnodeop_opv_desc;
  110 
  111 const struct vnodeopv_desc * const msdosfs_vnodeopv_descs[] = {
  112         &msdosfs_vnodeop_opv_desc,
  113         NULL,
  114 };
  115 
  116 struct vfsops msdosfs_vfsops = {
  117         MOUNT_MSDOS,
  118         msdosfs_mount,
  119         msdosfs_start,
  120         msdosfs_unmount,
  121         msdosfs_root,
  122         msdosfs_quotactl,
  123         msdosfs_statfs,
  124         msdosfs_sync,
  125         msdosfs_vget,
  126         msdosfs_fhtovp,
  127         msdosfs_vptofh,
  128         msdosfs_init,
  129         msdosfs_reinit,
  130         msdosfs_done,
  131         NULL,
  132         msdosfs_mountroot,
  133         msdosfs_checkexp,
  134         msdosfs_vnodeopv_descs,
  135 };
  136 
  137 static int
  138 update_mp(mp, argp)
  139         struct mount *mp;
  140         struct msdosfs_args *argp;
  141 {
  142         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  143         int error;
  144 
  145         pmp->pm_gid = argp->gid;
  146         pmp->pm_uid = argp->uid;
  147         pmp->pm_mask = argp->mask & ALLPERMS;
  148         pmp->pm_dirmask = argp->dirmask & ALLPERMS;
  149         pmp->pm_gmtoff = argp->gmtoff;
  150         pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
  151 
  152         /*
  153          * GEMDOS knows nothing (yet) about win95
  154          */
  155         if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
  156                 pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
  157 
  158         if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
  159                 pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
  160         else if (!(pmp->pm_flags &
  161             (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
  162                 struct vnode *rootvp;
  163 
  164                 /*
  165                  * Try to divine whether to support Win'95 long filenames
  166                  */
  167                 if (FAT32(pmp))
  168                         pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
  169                 else {
  170                         if ((error = msdosfs_root(mp, &rootvp)) != 0)
  171                                 return error;
  172                         pmp->pm_flags |= findwin95(VTODE(rootvp))
  173                                 ? MSDOSFSMNT_LONGNAME
  174                                         : MSDOSFSMNT_SHORTNAME;
  175                         vput(rootvp);
  176                 }
  177         }
  178         return 0;
  179 }
  180 
  181 int
  182 msdosfs_mountroot()
  183 {
  184         struct mount *mp;
  185         struct proc *p = curproc;       /* XXX */
  186         int error;
  187         struct msdosfs_args args;
  188 
  189         if (root_device->dv_class != DV_DISK)
  190                 return (ENODEV);
  191 
  192         /*
  193          * Get vnodes for swapdev and rootdev.
  194          */
  195         if (bdevvp(rootdev, &rootvp))
  196                 panic("msdosfs_mountroot: can't setup rootvp");
  197 
  198         if ((error = vfs_rootmountalloc(MOUNT_MSDOS, "root_device", &mp))) {
  199                 vrele(rootvp);
  200                 return (error);
  201         }
  202 
  203         args.flags = MSDOSFSMNT_VERSIONED;
  204         args.uid = 0;
  205         args.gid = 0;
  206         args.mask = 0777;
  207         args.version = MSDOSFSMNT_VERSION;
  208         args.dirmask = 0777;
  209 
  210         if ((error = msdosfs_mountfs(rootvp, mp, p, &args)) != 0) {
  211                 mp->mnt_op->vfs_refcount--;
  212                 vfs_unbusy(mp);
  213                 free(mp, M_MOUNT);
  214                 vrele(rootvp);
  215                 return (error);
  216         }
  217 
  218         if ((error = update_mp(mp, &args)) != 0) {
  219                 (void)msdosfs_unmount(mp, 0, p);
  220                 vfs_unbusy(mp);
  221                 free(mp, M_MOUNT);
  222                 vrele(rootvp);
  223                 return (error);
  224         }
  225 
  226         simple_lock(&mountlist_slock);
  227         CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
  228         simple_unlock(&mountlist_slock);
  229         (void)msdosfs_statfs(mp, &mp->mnt_stat, p);
  230         vfs_unbusy(mp);
  231         return (0);
  232 }
  233 
  234 /*
  235  * mp - path - addr in user space of mount point (ie /usr or whatever)
  236  * data - addr in user space of mount params including the name of the block
  237  * special file to treat as a filesystem.
  238  */
  239 int
  240 msdosfs_mount(mp, path, data, ndp, p)
  241         struct mount *mp;
  242         const char *path;
  243         void *data;
  244         struct nameidata *ndp;
  245         struct proc *p;
  246 {
  247         struct vnode *devvp;      /* vnode for blk device to mount */
  248         struct msdosfs_args args; /* will hold data from mount request */
  249         /* msdosfs specific mount control block */
  250         struct msdosfsmount *pmp = NULL;
  251         int error, flags;
  252         mode_t accessmode;
  253 
  254         if (mp->mnt_flag & MNT_GETARGS) {
  255                 pmp = VFSTOMSDOSFS(mp);
  256                 if (pmp == NULL)
  257                         return EIO;
  258                 args.fspec = NULL;
  259                 args.uid = pmp->pm_uid;
  260                 args.gid = pmp->pm_gid;
  261                 args.mask = pmp->pm_mask;
  262                 args.flags = pmp->pm_flags;
  263                 args.version = MSDOSFSMNT_VERSION;
  264                 args.dirmask = pmp->pm_dirmask;
  265                 args.gmtoff = pmp->pm_gmtoff;
  266                 vfs_showexport(mp, &args.export, &pmp->pm_export);
  267                 return copyout(&args, data, sizeof(args));
  268         }
  269         error = copyin(data, &args, sizeof(struct msdosfs_args));
  270         if (error)
  271                 return (error);
  272 
  273         /*
  274          * If not versioned (i.e. using old mount_msdos(8)), fill in
  275          * the additional structure items with suitable defaults.
  276          */
  277         if ((args.flags & MSDOSFSMNT_VERSIONED) == 0) {
  278                 args.version = 1;
  279                 args.dirmask = args.mask;
  280         }
  281 
  282         /*
  283          * If updating, check whether changing from read-only to
  284          * read/write; if there is no device name, that's all we do.
  285          */
  286         if (mp->mnt_flag & MNT_UPDATE) {
  287                 pmp = VFSTOMSDOSFS(mp);
  288                 error = 0;
  289                 if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
  290                         flags = WRITECLOSE;
  291                         if (mp->mnt_flag & MNT_FORCE)
  292                                 flags |= FORCECLOSE;
  293                         error = vflush(mp, NULLVP, flags);
  294                 }
  295                 if (!error && (mp->mnt_flag & MNT_RELOAD))
  296                         /* not yet implemented */
  297                         error = EOPNOTSUPP;
  298                 if (error)
  299                         return (error);
  300                 if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_iflag & IMNT_WANTRDWR)) {
  301                         /*
  302                          * If upgrade to read-write by non-root, then verify
  303                          * that user has necessary permissions on the device.
  304                          */
  305                         if (p->p_ucred->cr_uid != 0) {
  306                                 devvp = pmp->pm_devvp;
  307                                 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
  308                                 error = VOP_ACCESS(devvp, VREAD | VWRITE,
  309                                                    p->p_ucred, p);
  310                                 VOP_UNLOCK(devvp, 0);
  311                                 if (error)
  312                                         return (error);
  313                         }
  314                         pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
  315                 }
  316                 if (args.fspec == 0) {
  317 #ifdef  __notyet__              /* doesn't work correctly with current mountd   XXX */
  318                         if (args.flags & MSDOSFSMNT_MNTOPT) {
  319                                 pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
  320                                 pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
  321                                 if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
  322                                         pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
  323                         }
  324 #endif
  325                         /*
  326                          * Process export requests.
  327                          */
  328                         return (vfs_export(mp, &pmp->pm_export, &args.export));
  329                 }
  330         }
  331         /*
  332          * Not an update, or updating the name: look up the name
  333          * and verify that it refers to a sensible block device.
  334          */
  335         NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
  336         if ((error = namei(ndp)) != 0)
  337                 return (error);
  338         devvp = ndp->ni_vp;
  339 
  340         if (devvp->v_type != VBLK) {
  341                 vrele(devvp);
  342                 return (ENOTBLK);
  343         }
  344         if (bdevsw_lookup(devvp->v_rdev) == NULL) {
  345                 vrele(devvp);
  346                 return (ENXIO);
  347         }
  348         /*
  349          * If mount by non-root, then verify that user has necessary
  350          * permissions on the device.
  351          */
  352         if (p->p_ucred->cr_uid != 0) {
  353                 accessmode = VREAD;
  354                 if ((mp->mnt_flag & MNT_RDONLY) == 0)
  355                         accessmode |= VWRITE;
  356                 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
  357                 error = VOP_ACCESS(devvp, accessmode, p->p_ucred, p);
  358                 VOP_UNLOCK(devvp, 0);
  359                 if (error) {
  360                         vrele(devvp);
  361                         return (error);
  362                 }
  363         }
  364         if ((mp->mnt_flag & MNT_UPDATE) == 0) {
  365                 error = msdosfs_mountfs(devvp, mp, p, &args);
  366 #ifdef MSDOSFS_DEBUG            /* only needed for the printf below */
  367                 pmp = VFSTOMSDOSFS(mp);
  368 #endif
  369         } else {
  370                 if (devvp != pmp->pm_devvp)
  371                         error = EINVAL; /* needs translation */
  372                 else
  373                         vrele(devvp);
  374         }
  375         if (error) {
  376                 vrele(devvp);
  377                 return (error);
  378         }
  379 
  380         if ((error = update_mp(mp, &args)) != 0) {
  381                 msdosfs_unmount(mp, MNT_FORCE, p);
  382                 return error;
  383         }
  384 
  385 #ifdef MSDOSFS_DEBUG
  386         printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
  387 #endif
  388         return set_statfs_info(path, UIO_USERSPACE, args.fspec, UIO_USERSPACE,
  389             mp, p);
  390 }
  391 
  392 int
  393 msdosfs_mountfs(devvp, mp, p, argp)
  394         struct vnode *devvp;
  395         struct mount *mp;
  396         struct proc *p;
  397         struct msdosfs_args *argp;
  398 {
  399         struct msdosfsmount *pmp;
  400         struct buf *bp;
  401         dev_t dev = devvp->v_rdev;
  402         struct partinfo dpart;
  403         union bootsector *bsp;
  404         struct byte_bpb33 *b33;
  405         struct byte_bpb50 *b50;
  406         struct byte_bpb710 *b710;
  407         u_int8_t SecPerClust;
  408         int     ronly, error;
  409         int     bsize = 0, dtype = 0, tmp;
  410         u_long  dirsperblk;
  411 
  412         /*
  413          * Disallow multiple mounts of the same device.
  414          * Disallow mounting of a device that is currently in use
  415          * (except for root, which might share swap device for miniroot).
  416          * Flush out any old buffers remaining from a previous use.
  417          */
  418         if ((error = vfs_mountedon(devvp)) != 0)
  419                 return (error);
  420         if (vcount(devvp) > 1 && devvp != rootvp)
  421                 return (EBUSY);
  422         if ((error = vinvalbuf(devvp, V_SAVE, p->p_ucred, p, 0, 0)) != 0)
  423                 return (error);
  424 
  425         ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
  426         error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p);
  427         if (error)
  428                 return (error);
  429 
  430         bp  = NULL; /* both used in error_exit */
  431         pmp = NULL;
  432 
  433         if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
  434                 /*
  435                  * We need the disklabel to calculate the size of a FAT entry
  436                  * later on. Also make sure the partition contains a filesystem
  437                  * of type FS_MSDOS. This doesn't work for floppies, so we have
  438                  * to check for them too.
  439                  *
  440                  * At least some parts of the msdos fs driver seem to assume
  441                  * that the size of a disk block will always be 512 bytes.
  442                  * Let's check it...
  443                  */
  444                 error = VOP_IOCTL(devvp, DIOCGPART, &dpart, FREAD, NOCRED, p);
  445                 if (error)
  446                         goto error_exit;
  447                 tmp   = dpart.part->p_fstype;
  448                 dtype = dpart.disklab->d_type;
  449                 bsize = dpart.disklab->d_secsize;
  450                 if (bsize != 512 || (dtype!=DTYPE_FLOPPY && tmp!=FS_MSDOS)) {
  451                         error = EINVAL;
  452                         goto error_exit;
  453                 }
  454         }
  455 
  456         /*
  457          * Read the boot sector of the filesystem, and then check the
  458          * boot signature.  If not a dos boot sector then error out.
  459          */
  460         if ((error = bread(devvp, 0, 512, NOCRED, &bp)) != 0)
  461                 goto error_exit;
  462         bp->b_flags |= B_AGE;
  463         bsp = (union bootsector *)bp->b_data;
  464         b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
  465         b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
  466         b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
  467 
  468         if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
  469                 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
  470                     || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
  471                         error = EINVAL;
  472                         goto error_exit;
  473                 }
  474         }
  475 
  476         pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
  477         memset(pmp, 0, sizeof *pmp);
  478         pmp->pm_mountp = mp;
  479 
  480         /*
  481          * Compute several useful quantities from the bpb in the
  482          * bootsector.  Copy in the dos 5 variant of the bpb then fix up
  483          * the fields that are different between dos 5 and dos 3.3.
  484          */
  485         SecPerClust = b50->bpbSecPerClust;
  486         pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
  487         pmp->pm_ResSectors = getushort(b50->bpbResSectors);
  488         pmp->pm_FATs = b50->bpbFATs;
  489         pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
  490         pmp->pm_Sectors = getushort(b50->bpbSectors);
  491         pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
  492         pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
  493         pmp->pm_Heads = getushort(b50->bpbHeads);
  494         pmp->pm_Media = b50->bpbMedia;
  495 
  496         if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
  497                 /* XXX - We should probably check more values here */
  498                 if (!pmp->pm_BytesPerSec || !SecPerClust
  499                         || pmp->pm_Heads > 255 || pmp->pm_SecPerTrack > 63) {
  500                         error = EINVAL;
  501                         goto error_exit;
  502                 }
  503         }
  504 
  505         if (pmp->pm_Sectors == 0) {
  506                 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
  507                 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
  508         } else {
  509                 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
  510                 pmp->pm_HugeSectors = pmp->pm_Sectors;
  511         }
  512         dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
  513         if (pmp->pm_HugeSectors > 0xffffffff / dirsperblk + 1) {
  514                 /*
  515                  * We cannot deal currently with this size of disk
  516                  * due to fileid limitations (see msdosfs_getattr and
  517                  * msdosfs_readdir)
  518                  */
  519                 error = EINVAL;
  520                 goto error_exit;
  521         }
  522 
  523         if (pmp->pm_RootDirEnts == 0) {
  524                 if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
  525                     || bsp->bs710.bsBootSectSig3 != BOOTSIG3
  526                     || pmp->pm_Sectors
  527                     || pmp->pm_FATsecs
  528                     || getushort(b710->bpbFSVers)) {
  529                         error = EINVAL;
  530                         goto error_exit;
  531                 }
  532                 pmp->pm_fatmask = FAT32_MASK;
  533                 pmp->pm_fatmult = 4;
  534                 pmp->pm_fatdiv = 1;
  535                 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
  536 
  537                 /* mirrorring is enabled if the FATMIRROR bit is not set */
  538                 if ((getushort(b710->bpbExtFlags) & FATMIRROR) == 0)
  539                         pmp->pm_flags |= MSDOSFS_FATMIRROR;
  540                 else
  541                         pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
  542         } else
  543                 pmp->pm_flags |= MSDOSFS_FATMIRROR;
  544 
  545         if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
  546                 if (FAT32(pmp)) {
  547                         /*
  548                          * GEMDOS doesn't know fat32.
  549                          */
  550                         error = EINVAL;
  551                         goto error_exit;
  552                 }
  553 
  554                 /*
  555                  * Check a few values (could do some more):
  556                  * - logical sector size: power of 2, >= block size
  557                  * - sectors per cluster: power of 2, >= 1
  558                  * - number of sectors:   >= 1, <= size of partition
  559                  */
  560                 if ( (SecPerClust == 0)
  561                   || (SecPerClust & (SecPerClust - 1))
  562                   || (pmp->pm_BytesPerSec < bsize)
  563                   || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
  564                   || (pmp->pm_HugeSectors == 0)
  565                   || (pmp->pm_HugeSectors * (pmp->pm_BytesPerSec / bsize)
  566                                                         > dpart.part->p_size)
  567                    ) {
  568                         error = EINVAL;
  569                         goto error_exit;
  570                 }
  571                 /*
  572                  * XXX - Many parts of the msdos fs driver seem to assume that
  573                  * the number of bytes per logical sector (BytesPerSec) will
  574                  * always be the same as the number of bytes per disk block
  575                  * Let's pretend it is.
  576                  */
  577                 tmp = pmp->pm_BytesPerSec / bsize;
  578                 pmp->pm_BytesPerSec  = bsize;
  579                 pmp->pm_HugeSectors *= tmp;
  580                 pmp->pm_HiddenSects *= tmp;
  581                 pmp->pm_ResSectors  *= tmp;
  582                 pmp->pm_Sectors     *= tmp;
  583                 pmp->pm_FATsecs     *= tmp;
  584                 SecPerClust         *= tmp;
  585         }
  586         pmp->pm_fatblk = pmp->pm_ResSectors;
  587         if (FAT32(pmp)) {
  588                 pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
  589                 pmp->pm_firstcluster = pmp->pm_fatblk
  590                         + (pmp->pm_FATs * pmp->pm_FATsecs);
  591                 pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
  592         } else {
  593                 pmp->pm_rootdirblk = pmp->pm_fatblk +
  594                         (pmp->pm_FATs * pmp->pm_FATsecs);
  595                 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
  596                                        + pmp->pm_BytesPerSec - 1)
  597                         / pmp->pm_BytesPerSec;/* in sectors */
  598                 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
  599         }
  600 
  601         pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
  602             SecPerClust;
  603         pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
  604         pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
  605 
  606         if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
  607                 if (pmp->pm_nmbrofclusters <= (0xff0 - 2)
  608                       && (dtype == DTYPE_FLOPPY
  609                           || (dtype == DTYPE_VND
  610                                 && (pmp->pm_Heads == 1 || pmp->pm_Heads == 2)))
  611                     ) {
  612                         pmp->pm_fatmask = FAT12_MASK;
  613                         pmp->pm_fatmult = 3;
  614                         pmp->pm_fatdiv = 2;
  615                 } else {
  616                         pmp->pm_fatmask = FAT16_MASK;
  617                         pmp->pm_fatmult = 2;
  618                         pmp->pm_fatdiv = 1;
  619                 }
  620         } else if (pmp->pm_fatmask == 0) {
  621                 if (pmp->pm_maxcluster
  622                     <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
  623                         /*
  624                          * This will usually be a floppy disk. This size makes
  625                          * sure that one fat entry will not be split across
  626                          * multiple blocks.
  627                          */
  628                         pmp->pm_fatmask = FAT12_MASK;
  629                         pmp->pm_fatmult = 3;
  630                         pmp->pm_fatdiv = 2;
  631                 } else {
  632                         pmp->pm_fatmask = FAT16_MASK;
  633                         pmp->pm_fatmult = 2;
  634                         pmp->pm_fatdiv = 1;
  635                 }
  636         }
  637         if (FAT12(pmp))
  638                 pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
  639         else
  640                 pmp->pm_fatblocksize = MAXBSIZE;
  641 
  642         pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
  643         pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
  644 
  645         /*
  646          * Compute mask and shift value for isolating cluster relative byte
  647          * offsets and cluster numbers from a file offset.
  648          */
  649         pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
  650         pmp->pm_crbomask = pmp->pm_bpcluster - 1;
  651         pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
  652 
  653         /*
  654          * Check for valid cluster size
  655          * must be a power of 2
  656          */
  657         if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
  658                 error = EINVAL;
  659                 goto error_exit;
  660         }
  661 
  662         /*
  663          * Release the bootsector buffer.
  664          */
  665         brelse(bp);
  666         bp = NULL;
  667 
  668         /*
  669          * Check FSInfo.
  670          */
  671         if (pmp->pm_fsinfo) {
  672                 struct fsinfo *fp;
  673 
  674                 if ((error = bread(devvp, pmp->pm_fsinfo, 1024, NOCRED, &bp)) != 0)
  675                         goto error_exit;
  676                 fp = (struct fsinfo *)bp->b_data;
  677                 if (!memcmp(fp->fsisig1, "RRaA", 4)
  678                     && !memcmp(fp->fsisig2, "rrAa", 4)
  679                     && !memcmp(fp->fsisig3, "\0\0\125\252", 4)
  680                     && !memcmp(fp->fsisig4, "\0\0\125\252", 4))
  681                         pmp->pm_nxtfree = getulong(fp->fsinxtfree);
  682                 else
  683                         pmp->pm_fsinfo = 0;
  684                 brelse(bp);
  685                 bp = NULL;
  686         }
  687 
  688         /*
  689          * Check and validate (or perhaps invalidate?) the fsinfo structure?
  690          * XXX
  691          */
  692         if (pmp->pm_fsinfo) {
  693                 if (pmp->pm_nxtfree == (u_long)-1)
  694                         pmp->pm_fsinfo = 0;
  695         }
  696 
  697         /*
  698          * Allocate memory for the bitmap of allocated clusters, and then
  699          * fill it in.
  700          */
  701         pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
  702                                    / N_INUSEBITS)
  703                                   * sizeof(*pmp->pm_inusemap),
  704                                   M_MSDOSFSFAT, M_WAITOK);
  705 
  706         /*
  707          * fillinusemap() needs pm_devvp.
  708          */
  709         pmp->pm_dev = dev;
  710         pmp->pm_devvp = devvp;
  711 
  712         /*
  713          * Have the inuse map filled in.
  714          */
  715         if ((error = fillinusemap(pmp)) != 0)
  716                 goto error_exit;
  717 
  718         /*
  719          * If they want fat updates to be synchronous then let them suffer
  720          * the performance degradation in exchange for the on disk copy of
  721          * the fat being correct just about all the time.  I suppose this
  722          * would be a good thing to turn on if the kernel is still flakey.
  723          */
  724         if (mp->mnt_flag & MNT_SYNCHRONOUS)
  725                 pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
  726 
  727         /*
  728          * Finish up.
  729          */
  730         if (ronly)
  731                 pmp->pm_flags |= MSDOSFSMNT_RONLY;
  732         else
  733                 pmp->pm_fmod = 1;
  734         mp->mnt_data = pmp;
  735         mp->mnt_stat.f_fsid.val[0] = (long)dev;
  736         mp->mnt_stat.f_fsid.val[1] = makefstype(MOUNT_MSDOS);
  737         mp->mnt_flag |= MNT_LOCAL;
  738         mp->mnt_dev_bshift = pmp->pm_bnshift;
  739         mp->mnt_fs_bshift = pmp->pm_cnshift;
  740 
  741 #ifdef QUOTA
  742         /*
  743          * If we ever do quotas for DOS filesystems this would be a place
  744          * to fill in the info in the msdosfsmount structure. You dolt,
  745          * quotas on dos filesystems make no sense because files have no
  746          * owners on dos filesystems. of course there is some empty space
  747          * in the directory entry where we could put uid's and gid's.
  748          */
  749 #endif
  750         devvp->v_specmountpoint = mp;
  751 
  752         return (0);
  753 
  754 error_exit:;
  755         if (bp)
  756                 brelse(bp);
  757         vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
  758         (void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, NOCRED, p);
  759         VOP_UNLOCK(devvp, 0);
  760         if (pmp) {
  761                 if (pmp->pm_inusemap)
  762                         free(pmp->pm_inusemap, M_MSDOSFSFAT);
  763                 free(pmp, M_MSDOSFSMNT);
  764                 mp->mnt_data = NULL;
  765         }
  766         return (error);
  767 }
  768 
  769 int
  770 msdosfs_start(mp, flags, p)
  771         struct mount *mp;
  772         int flags;
  773         struct proc *p;
  774 {
  775 
  776         return (0);
  777 }
  778 
  779 /*
  780  * Unmount the filesystem described by mp.
  781  */
  782 int
  783 msdosfs_unmount(mp, mntflags, p)
  784         struct mount *mp;
  785         int mntflags;
  786         struct proc *p;
  787 {
  788         struct msdosfsmount *pmp;
  789         int error, flags;
  790 
  791         flags = 0;
  792         if (mntflags & MNT_FORCE)
  793                 flags |= FORCECLOSE;
  794 #ifdef QUOTA
  795 #endif
  796         if ((error = vflush(mp, NULLVP, flags)) != 0)
  797                 return (error);
  798         pmp = VFSTOMSDOSFS(mp);
  799         if (pmp->pm_devvp->v_type != VBAD)
  800                 pmp->pm_devvp->v_specmountpoint = NULL;
  801 #ifdef MSDOSFS_DEBUG
  802         {
  803                 struct vnode *vp = pmp->pm_devvp;
  804 
  805                 printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
  806                 printf("flag %08x, usecount %d, writecount %ld, holdcnt %ld\n",
  807                     vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
  808                 printf("id %lu, mount %p, op %p\n",
  809                     vp->v_id, vp->v_mount, vp->v_op);
  810                 printf("freef %p, freeb %p, mount %p\n",
  811                     vp->v_freelist.tqe_next, vp->v_freelist.tqe_prev,
  812                     vp->v_mount);
  813                 printf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
  814                     vp->v_cleanblkhd.lh_first,
  815                     vp->v_dirtyblkhd.lh_first,
  816                     vp->v_numoutput, vp->v_type);
  817                 printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
  818                     vp->v_socket, vp->v_tag,
  819                     ((u_int *)vp->v_data)[0],
  820                     ((u_int *)vp->v_data)[1]);
  821         }
  822 #endif
  823         vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
  824         error = VOP_CLOSE(pmp->pm_devvp,
  825             pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD|FWRITE, NOCRED, p);
  826         vput(pmp->pm_devvp);
  827         free(pmp->pm_inusemap, M_MSDOSFSFAT);
  828         free(pmp, M_MSDOSFSMNT);
  829         mp->mnt_data = NULL;
  830         mp->mnt_flag &= ~MNT_LOCAL;
  831         return (error);
  832 }
  833 
  834 int
  835 msdosfs_root(mp, vpp)
  836         struct mount *mp;
  837         struct vnode **vpp;
  838 {
  839         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  840         struct denode *ndep;
  841         int error;
  842 
  843 #ifdef MSDOSFS_DEBUG
  844         printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
  845 #endif
  846         if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep)) != 0)
  847                 return (error);
  848         *vpp = DETOV(ndep);
  849         return (0);
  850 }
  851 
  852 int
  853 msdosfs_quotactl(mp, cmds, uid, arg, p)
  854         struct mount *mp;
  855         int cmds;
  856         uid_t uid;
  857         caddr_t arg;
  858         struct proc *p;
  859 {
  860 
  861 #ifdef QUOTA
  862         return (EOPNOTSUPP);
  863 #else
  864         return (EOPNOTSUPP);
  865 #endif
  866 }
  867 
  868 int
  869 msdosfs_statfs(mp, sbp, p)
  870         struct mount *mp;
  871         struct statfs *sbp;
  872         struct proc *p;
  873 {
  874         struct msdosfsmount *pmp;
  875 
  876         pmp = VFSTOMSDOSFS(mp);
  877 #ifdef COMPAT_09
  878         sbp->f_type = 4;
  879 #else
  880         sbp->f_type = 0;
  881 #endif
  882         sbp->f_bsize = pmp->pm_bpcluster;
  883         sbp->f_iosize = pmp->pm_bpcluster;
  884         sbp->f_blocks = pmp->pm_nmbrofclusters;
  885         sbp->f_bfree = pmp->pm_freeclustercount;
  886         sbp->f_bavail = pmp->pm_freeclustercount;
  887         sbp->f_files = pmp->pm_RootDirEnts;                     /* XXX */
  888         sbp->f_ffree = 0;       /* what to put in here? */
  889         copy_statfs_info(sbp, mp);
  890         return (0);
  891 }
  892 
  893 int
  894 msdosfs_sync(mp, waitfor, cred, p)
  895         struct mount *mp;
  896         int waitfor;
  897         struct ucred *cred;
  898         struct proc *p;
  899 {
  900         struct vnode *vp, *nvp;
  901         struct denode *dep;
  902         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  903         int error, allerror = 0;
  904 
  905         /*
  906          * If we ever switch to not updating all of the fats all the time,
  907          * this would be the place to update them from the first one.
  908          */
  909         if (pmp->pm_fmod != 0) {
  910                 if (pmp->pm_flags & MSDOSFSMNT_RONLY)
  911                         panic("msdosfs_sync: rofs mod");
  912                 else {
  913                         /* update fats here */
  914                 }
  915         }
  916         /*
  917          * Write back each (modified) denode.
  918          */
  919         simple_lock(&mntvnode_slock);
  920 loop:
  921         for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
  922                 /*
  923                  * If the vnode that we are about to sync is no longer
  924                  * assoicated with this mount point, start over.
  925                  */
  926                 if (vp->v_mount != mp)
  927                         goto loop;
  928                 simple_lock(&vp->v_interlock);
  929                 nvp = vp->v_mntvnodes.le_next;
  930                 dep = VTODE(vp);
  931                 if (waitfor == MNT_LAZY || vp->v_type == VNON ||
  932                     (((dep->de_flag &
  933                     (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0) &&
  934                      (LIST_EMPTY(&vp->v_dirtyblkhd) &&
  935                       vp->v_uobj.uo_npages == 0))) {
  936                         simple_unlock(&vp->v_interlock);
  937                         continue;
  938                 }
  939                 simple_unlock(&mntvnode_slock);
  940                 error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK);
  941                 if (error) {
  942                         simple_lock(&mntvnode_slock);
  943                         if (error == ENOENT)
  944                                 goto loop;
  945                         continue;
  946                 }
  947                 if ((error = VOP_FSYNC(vp, cred,
  948                     waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0, p)) != 0)
  949                         allerror = error;
  950                 vput(vp);
  951                 simple_lock(&mntvnode_slock);
  952         }
  953         simple_unlock(&mntvnode_slock);
  954         /*
  955          * Force stale file system control information to be flushed.
  956          */
  957         if ((error = VOP_FSYNC(pmp->pm_devvp, cred,
  958             waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0, p)) != 0)
  959                 allerror = error;
  960 #ifdef QUOTA
  961         /* qsync(mp); */
  962 #endif
  963         return (allerror);
  964 }
  965 
  966 int
  967 msdosfs_fhtovp(mp, fhp, vpp)
  968         struct mount *mp;
  969         struct fid *fhp;
  970         struct vnode **vpp;
  971 {
  972         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  973         struct defid *defhp = (struct defid *) fhp;
  974         struct denode *dep;
  975         int error;
  976 
  977         error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
  978         if (error) {
  979                 *vpp = NULLVP;
  980                 return (error);
  981         }
  982         *vpp = DETOV(dep);
  983         return (0);
  984 }
  985 
  986 int
  987 msdosfs_checkexp(mp, nam, exflagsp, credanonp)
  988         struct mount *mp;
  989         struct mbuf *nam;
  990         int *exflagsp;
  991         struct ucred **credanonp;
  992 {
  993         struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
  994         struct netcred *np;
  995 
  996         np = vfs_export_lookup(mp, &pmp->pm_export, nam);
  997         if (np == NULL)
  998                 return (EACCES);
  999         *exflagsp = np->netc_exflags;
 1000         *credanonp = &np->netc_anon;
 1001         return (0);
 1002 }
 1003 
 1004 int
 1005 msdosfs_vptofh(vp, fhp)
 1006         struct vnode *vp;
 1007         struct fid *fhp;
 1008 {
 1009         struct denode *dep;
 1010         struct defid *defhp;
 1011 
 1012         dep = VTODE(vp);
 1013         defhp = (struct defid *)fhp;
 1014         defhp->defid_len = sizeof(struct defid);
 1015         defhp->defid_dirclust = dep->de_dirclust;
 1016         defhp->defid_dirofs = dep->de_diroffset;
 1017         /* defhp->defid_gen = dep->de_gen; */
 1018         return (0);
 1019 }
 1020 
 1021 int
 1022 msdosfs_vget(mp, ino, vpp)
 1023         struct mount *mp;
 1024         ino_t ino;
 1025         struct vnode **vpp;
 1026 {
 1027 
 1028         return (EOPNOTSUPP);
 1029 }
 1030 
 1031 SYSCTL_SETUP(sysctl_vfs_msdosfs_setup, "sysctl vfs.msdosfs subtree setup")
 1032 {
 1033 
 1034         sysctl_createv(clog, 0, NULL, NULL,
 1035                        CTLFLAG_PERMANENT,
 1036                        CTLTYPE_NODE, "vfs", NULL,
 1037                        NULL, 0, NULL, 0,
 1038                        CTL_VFS, CTL_EOL);
 1039         sysctl_createv(clog, 0, NULL, NULL,
 1040                        CTLFLAG_PERMANENT,
 1041                        CTLTYPE_NODE, "msdosfs",
 1042                        SYSCTL_DESCR("MS-DOS file system"),
 1043                        NULL, 0, NULL, 0,
 1044                        CTL_VFS, 4, CTL_EOL);
 1045         /*
 1046          * XXX the "4" above could be dynamic, thereby eliminating one
 1047          * more instance of the "number to vfs" mapping problem, but
 1048          * "4" is the order as taken from sys/mount.h
 1049          */
 1050 }

Cache object: 867e3bd00b9a4cedf2eaf008e4e27c4c


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