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usr.sbin/makefs/msdos/msdosfs_vfsops.c

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/*-
* Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
* Copyright (C) 1994, 1995, 1997 TooLs GmbH.
* All rights reserved.
* Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.10 2016/01/30 09:59:27 mlelstv Exp $");
#include <sys/param.h>
#include <ffs/buf.h>
#include <fs/msdosfs/bpb.h>
#include <fs/msdosfs/bootsect.h>
#include <fs/msdosfs/direntry.h>
#include <fs/msdosfs/denode.h>
#include <fs/msdosfs/msdosfsmount.h>
#include <fs/msdosfs/fat.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <util.h>
#include "makefs.h"
#include "msdos.h"
#include "mkfs_msdos.h"
#ifdef MSDOSFS_DEBUG
#define DPRINTF(a) printf a
#else
#define DPRINTF(a)
#endif
struct msdosfsmount *
msdosfs_mount(struct vnode *devvp, int flags)
{
struct msdosfsmount *pmp = NULL;
struct buf *bp;
union bootsector *bsp;
struct byte_bpb33 *b33;
struct byte_bpb50 *b50;
struct byte_bpb710 *b710;
uint8_t SecPerClust;
int ronly = 0, error, tmp;
int bsize;
struct msdos_options *m = devvp->fs->fs_specific;
uint64_t psize = m->create_size;
unsigned secsize = 512;
DPRINTF(("%s(bread 0)\n", __func__));
if ((error = bread(devvp, 0, secsize, 0, &bp)) != 0)
goto error_exit;
bsp = (union bootsector *)bp->b_data;
b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
if (!(flags & MSDOSFSMNT_GEMDOSFS)) {
if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
|| bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
DPRINTF(("bootsig0 %d bootsig1 %d\n",
bsp->bs50.bsBootSectSig0,
bsp->bs50.bsBootSectSig1));
error = EINVAL;
goto error_exit;
}
bsize = 0;
} else
bsize = 512;
pmp = ecalloc(1, sizeof *pmp);
/*
* Compute several useful quantities from the bpb in the
* bootsector. Copy in the dos 5 variant of the bpb then fix up
* the fields that are different between dos 5 and dos 3.3.
*/
SecPerClust = b50->bpbSecPerClust;
pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
pmp->pm_ResSectors = getushort(b50->bpbResSectors);
pmp->pm_FATs = b50->bpbFATs;
pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
pmp->pm_Sectors = getushort(b50->bpbSectors);
pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
pmp->pm_Heads = getushort(b50->bpbHeads);
pmp->pm_Media = b50->bpbMedia;
DPRINTF(("%s(BytesPerSec=%u, ResSectors=%u, FATs=%d, RootDirEnts=%u, "
"Sectors=%u, FATsecs=%lu, SecPerTrack=%u, Heads=%u, Media=%u)\n",
__func__, pmp->pm_BytesPerSec, pmp->pm_ResSectors, pmp->pm_FATs,
pmp->pm_RootDirEnts, pmp->pm_Sectors, pmp->pm_FATsecs,
pmp->pm_SecPerTrack, pmp->pm_Heads, pmp->pm_Media));
if (!(flags & MSDOSFSMNT_GEMDOSFS)) {
/* XXX - We should probably check more values here */
if (!pmp->pm_BytesPerSec || !SecPerClust
|| pmp->pm_SecPerTrack > 63) {
DPRINTF(("bytespersec %d secperclust %d "
"secpertrack %d\n",
pmp->pm_BytesPerSec, SecPerClust,
pmp->pm_SecPerTrack));
error = EINVAL;
goto error_exit;
}
}
pmp->pm_flags = flags & MSDOSFSMNT_MNTOPT;
if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
if (pmp->pm_Sectors == 0) {
pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
} else {
pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
pmp->pm_HugeSectors = pmp->pm_Sectors;
}
if (pmp->pm_RootDirEnts == 0) {
unsigned short vers = getushort(b710->bpbFSVers);
/*
* Some say that bsBootSectSig[23] must be zero, but
* Windows does not require this and some digital cameras
* do not set these to zero. Therefore, do not insist.
*/
if (pmp->pm_Sectors || pmp->pm_FATsecs || vers) {
DPRINTF(("sectors %d fatsecs %lu vers %d\n",
pmp->pm_Sectors, pmp->pm_FATsecs, vers));
error = EINVAL;
goto error_exit;
}
pmp->pm_fatmask = FAT32_MASK;
pmp->pm_fatmult = 4;
pmp->pm_fatdiv = 1;
pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
/* mirrorring is enabled if the FATMIRROR bit is not set */
if ((getushort(b710->bpbExtFlags) & FATMIRROR) == 0)
pmp->pm_flags |= MSDOSFS_FATMIRROR;
else
pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
} else
pmp->pm_flags |= MSDOSFS_FATMIRROR;
if (flags & MSDOSFSMNT_GEMDOSFS) {
if (FAT32(pmp)) {
DPRINTF(("FAT32 for GEMDOS\n"));
/*
* GEMDOS doesn't know FAT32.
*/
error = EINVAL;
goto error_exit;
}
/*
* Check a few values (could do some more):
* - logical sector size: power of 2, >= block size
* - sectors per cluster: power of 2, >= 1
* - number of sectors: >= 1, <= size of partition
*/
if ( (SecPerClust == 0)
|| (SecPerClust & (SecPerClust - 1))
|| (pmp->pm_BytesPerSec < bsize)
|| (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
|| (pmp->pm_HugeSectors == 0)
|| (pmp->pm_HugeSectors * (pmp->pm_BytesPerSec / bsize)
> psize)) {
DPRINTF(("consistency checks for GEMDOS\n"));
error = EINVAL;
goto error_exit;
}
/*
* XXX - Many parts of the msdosfs driver seem to assume that
* the number of bytes per logical sector (BytesPerSec) will
* always be the same as the number of bytes per disk block
* Let's pretend it is.
*/
tmp = pmp->pm_BytesPerSec / bsize;
pmp->pm_BytesPerSec = bsize;
pmp->pm_HugeSectors *= tmp;
pmp->pm_HiddenSects *= tmp;
pmp->pm_ResSectors *= tmp;
pmp->pm_Sectors *= tmp;
pmp->pm_FATsecs *= tmp;
SecPerClust *= tmp;
}
/* Check that fs has nonzero FAT size */
if (pmp->pm_FATsecs == 0) {
DPRINTF(("FATsecs is 0\n"));
error = EINVAL;
goto error_exit;
}
pmp->pm_fatblk = pmp->pm_ResSectors;
if (FAT32(pmp)) {
pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
pmp->pm_firstcluster = pmp->pm_fatblk
+ (pmp->pm_FATs * pmp->pm_FATsecs);
pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
} else {
pmp->pm_rootdirblk = pmp->pm_fatblk +
(pmp->pm_FATs * pmp->pm_FATsecs);
pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
+ pmp->pm_BytesPerSec - 1)
/ pmp->pm_BytesPerSec;/* in sectors */
pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
}
pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
SecPerClust;
pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
if (flags & MSDOSFSMNT_GEMDOSFS) {
if (pmp->pm_nmbrofclusters <= (0xff0 - 2)) {
pmp->pm_fatmask = FAT12_MASK;
pmp->pm_fatmult = 3;
pmp->pm_fatdiv = 2;
} else {
pmp->pm_fatmask = FAT16_MASK;
pmp->pm_fatmult = 2;
pmp->pm_fatdiv = 1;
}
} else if (pmp->pm_fatmask == 0) {
if (pmp->pm_maxcluster
<= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
/*
* This will usually be a floppy disk. This size makes
* sure that one FAT entry will not be split across
* multiple blocks.
*/
pmp->pm_fatmask = FAT12_MASK;
pmp->pm_fatmult = 3;
pmp->pm_fatdiv = 2;
} else {
pmp->pm_fatmask = FAT16_MASK;
pmp->pm_fatmult = 2;
pmp->pm_fatdiv = 1;
}
}
if (FAT12(pmp))
pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
else
pmp->pm_fatblocksize = MAXBSIZE;
pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
/*
* Compute mask and shift value for isolating cluster relative byte
* offsets and cluster numbers from a file offset.
*/
pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
pmp->pm_crbomask = pmp->pm_bpcluster - 1;
pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
DPRINTF(("%s(fatmask=%lu, fatmult=%u, fatdiv=%u, fatblocksize=%lu, "
"fatblocksec=%lu, bnshift=%lu, pbcluster=%lu, crbomask=%lu, "
"cnshift=%lu)\n",
__func__, pmp->pm_fatmask, pmp->pm_fatmult, pmp->pm_fatdiv,
pmp->pm_fatblocksize, pmp->pm_fatblocksec, pmp->pm_bnshift,
pmp->pm_bpcluster, pmp->pm_crbomask, pmp->pm_cnshift));
/*
* Check for valid cluster size
* must be a power of 2
*/
if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
DPRINTF(("bpcluster %lu cnshift %lu\n",
pmp->pm_bpcluster, pmp->pm_cnshift));
error = EINVAL;
goto error_exit;
}
/*
* Release the bootsector buffer.
*/
brelse(bp, BC_AGE);
bp = NULL;
/*
* Check FSInfo.
*/
if (pmp->pm_fsinfo) {
struct fsinfo *fp;
/*
* XXX If the fsinfo block is stored on media with
* 2KB or larger sectors, is the fsinfo structure
* padded at the end or in the middle?
*/
DPRINTF(("%s(bread %lu)\n", __func__,
(unsigned long)de_bn2kb(pmp, pmp->pm_fsinfo)));
if ((error = bread(devvp, de_bn2kb(pmp, pmp->pm_fsinfo),
pmp->pm_BytesPerSec, 0, &bp)) != 0)
goto error_exit;
fp = (struct fsinfo *)bp->b_data;
if (!memcmp(fp->fsisig1, "RRaA", 4)
&& !memcmp(fp->fsisig2, "rrAa", 4)
&& !memcmp(fp->fsisig3, "\0\0\125\252", 4)
&& !memcmp(fp->fsisig4, "\0\0\125\252", 4))
pmp->pm_nxtfree = getulong(fp->fsinxtfree);
else
pmp->pm_fsinfo = 0;
brelse(bp, 0);
bp = NULL;
}
/*
* Check and validate (or perhaps invalidate?) the fsinfo structure?
* XXX
*/
if (pmp->pm_fsinfo) {
if ((pmp->pm_nxtfree == 0xffffffffUL) ||
(pmp->pm_nxtfree > pmp->pm_maxcluster))
pmp->pm_fsinfo = 0;
}
/*
* Allocate memory for the bitmap of allocated clusters, and then
* fill it in.
*/
pmp->pm_inusemap = ecalloc(sizeof(*pmp->pm_inusemap),
((pmp->pm_maxcluster + N_INUSEBITS) / N_INUSEBITS));
/*
* fillinusemap() needs pm_devvp.
*/
pmp->pm_dev = 0;
pmp->pm_devvp = devvp;
/*
* Have the inuse map filled in.
*/
if ((error = fillinusemap(pmp)) != 0) {
DPRINTF(("fillinusemap %d\n", error));
goto error_exit;
}
/*
* Finish up.
*/
if (ronly)
pmp->pm_flags |= MSDOSFSMNT_RONLY;
else
pmp->pm_fmod = 1;
/*
* If we ever do quotas for DOS filesystems this would be a place
* to fill in the info in the msdosfsmount structure. You dolt,
* quotas on dos filesystems make no sense because files have no
* owners on dos filesystems. of course there is some empty space
* in the directory entry where we could put uid's and gid's.
*/
return pmp;
error_exit:
if (bp)
brelse(bp, BC_AGE);
if (pmp) {
if (pmp->pm_inusemap)
free(pmp->pm_inusemap);
free(pmp);
}
errno = error;
return NULL;
}
int
msdosfs_root(struct msdosfsmount *pmp, struct vnode *vp) {
struct denode *ndep;
int error;
*vp = *pmp->pm_devvp;
if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep)) != 0) {
errno = error;
return -1;
}
vp->v_data = ndep;
return 0;
}