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NetBSD/sys/fs/msdosfs/msdosfs_vfsops.c

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/* $NetBSD: msdosfs_vfsops.c,v 1.138 2022/04/16 07:58:21 hannken Exp $ */
/*-
* 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
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.138 2022/04/16 07:58:21 hannken Exp $");
#if defined(_KERNEL_OPT)
#include "opt_compat_netbsd.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/specfs/specdev.h> /* XXX */ /* defines v_rdev */
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/file.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <sys/dirent.h>
#include <sys/stat.h>
#include <sys/conf.h>
#include <sys/kauth.h>
#include <sys/module.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>
MODULE(MODULE_CLASS_VFS, msdos, NULL);
#ifdef MSDOSFS_DEBUG
#define DPRINTF(fmt, ...) uprintf("%s(): " fmt "\n", __func__, ##__VA_ARGS__)
#else
#define DPRINTF(fmt, ...)
#endif
#define GEMDOSFS_BSIZE 512
#define MSDOSFS_NAMEMAX(pmp) \
(pmp)->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12
int msdosfs_mountfs(struct vnode *, struct mount *, struct lwp *,
struct msdosfs_args *);
static int update_mp(struct mount *, struct msdosfs_args *);
MALLOC_JUSTDEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOS FS mount structure");
MALLOC_JUSTDEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOS FS FAT table");
MALLOC_JUSTDEFINE(M_MSDOSFSTMP, "MSDOSFS temp", "MSDOS FS temp. structures");
extern const struct vnodeopv_desc msdosfs_vnodeop_opv_desc;
const struct vnodeopv_desc * const msdosfs_vnodeopv_descs[] = {
&msdosfs_vnodeop_opv_desc,
NULL,
};
struct vfsops msdosfs_vfsops = {
.vfs_name = MOUNT_MSDOS,
.vfs_min_mount_data = sizeof (struct msdosfs_args),
.vfs_mount = msdosfs_mount,
.vfs_start = msdosfs_start,
.vfs_unmount = msdosfs_unmount,
.vfs_root = msdosfs_root,
.vfs_quotactl = (void *)eopnotsupp,
.vfs_statvfs = msdosfs_statvfs,
.vfs_sync = msdosfs_sync,
.vfs_vget = msdosfs_vget,
.vfs_loadvnode = msdosfs_loadvnode,
.vfs_fhtovp = msdosfs_fhtovp,
.vfs_vptofh = msdosfs_vptofh,
.vfs_init = msdosfs_init,
.vfs_reinit = msdosfs_reinit,
.vfs_done = msdosfs_done,
.vfs_mountroot = msdosfs_mountroot,
.vfs_snapshot = (void *)eopnotsupp,
.vfs_extattrctl = vfs_stdextattrctl,
.vfs_suspendctl = genfs_suspendctl,
.vfs_renamelock_enter = genfs_renamelock_enter,
.vfs_renamelock_exit = genfs_renamelock_exit,
.vfs_fsync = (void *)eopnotsupp,
.vfs_opv_descs = msdosfs_vnodeopv_descs
};
SYSCTL_SETUP(msdosfs_sysctl_setup, "msdosfs sysctl")
{
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "msdosfs",
SYSCTL_DESCR("MS-DOS file system"),
NULL, 0, NULL, 0,
CTL_VFS, 4, CTL_EOL);
/*
* XXX the "4" above could be dynamic, thereby eliminating one
* more instance of the "number to vfs" mapping problem, but
* "4" is the order as taken from sys/mount.h
*/
}
static int
msdos_modcmd(modcmd_t cmd, void *arg)
{
int error;
switch (cmd) {
case MODULE_CMD_INIT:
error = vfs_attach(&msdosfs_vfsops);
if (error != 0)
break;
break;
case MODULE_CMD_FINI:
error = vfs_detach(&msdosfs_vfsops);
if (error != 0)
break;
break;
default:
error = ENOTTY;
break;
}
return (error);
}
static int
update_mp(struct mount *mp, struct msdosfs_args *argp)
{
struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
int error;
pmp->pm_gid = argp->gid;
pmp->pm_uid = argp->uid;
pmp->pm_mask = argp->mask & ALLPERMS;
pmp->pm_dirmask = argp->dirmask & ALLPERMS;
pmp->pm_gmtoff = argp->gmtoff;
pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
/*
* GEMDOS knows nothing about win95 long filenames
*/
if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
else if (!(pmp->pm_flags &
(MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
struct vnode *rtvp;
/*
* Try to divine whether to support Win'95 long filenames
*/
if (FAT32(pmp))
pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
else {
error = msdosfs_root(mp, LK_EXCLUSIVE, &rtvp);
if (error != 0)
return error;
pmp->pm_flags |= msdosfs_findwin95(VTODE(rtvp))
? MSDOSFSMNT_LONGNAME
: MSDOSFSMNT_SHORTNAME;
vput(rtvp);
}
}
mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp);
return 0;
}
int
msdosfs_mountroot(void)
{
struct mount *mp;
struct lwp *l = curlwp; /* XXX */
int error;
struct msdosfs_args args;
if (device_class(root_device) != DV_DISK)
return (ENODEV);
if ((error = vfs_rootmountalloc(MOUNT_MSDOS, "root_device", &mp))) {
vrele(rootvp);
return (error);
}
args.flags = MSDOSFSMNT_VERSIONED;
args.uid = 0;
args.gid = 0;
args.mask = 0777;
args.version = MSDOSFSMNT_VERSION;
args.dirmask = 0777;
if ((error = msdosfs_mountfs(rootvp, mp, l, &args)) != 0) {
vfs_unbusy(mp);
vfs_rele(mp);
return (error);
}
if ((error = update_mp(mp, &args)) != 0) {
(void)msdosfs_unmount(mp, 0);
vfs_unbusy(mp);
vfs_rele(mp);
vrele(rootvp);
return (error);
}
mountlist_append(mp);
(void)msdosfs_statvfs(mp, &mp->mnt_stat);
vfs_unbusy(mp);
return (0);
}
/*
* mp - path - addr in user space of mount point (ie /usr or whatever)
* data - addr in user space of mount params including the name of the block
* special file to treat as a filesystem.
*/
int
msdosfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
{
struct lwp *l = curlwp;
struct vnode *devvp; /* vnode for blk device to mount */
struct msdosfs_args *args = data; /* holds data from mount request */
/* msdosfs specific mount control block */
struct msdosfsmount *pmp = NULL;
int error, flags;
mode_t accessmode;
if (args == NULL)
return EINVAL;
if (*data_len < sizeof *args)
return EINVAL;
if (mp->mnt_flag & MNT_GETARGS) {
pmp = VFSTOMSDOSFS(mp);
if (pmp == NULL)
return EIO;
args->fspec = NULL;
args->uid = pmp->pm_uid;
args->gid = pmp->pm_gid;
args->mask = pmp->pm_mask;
args->flags = pmp->pm_flags;
args->version = MSDOSFSMNT_VERSION;
args->dirmask = pmp->pm_dirmask;
args->gmtoff = pmp->pm_gmtoff;
*data_len = sizeof *args;
return 0;
}
/*
* If not versioned (i.e. using old mount_msdos(8)), fill in
* the additional structure items with suitable defaults.
*/
if ((args->flags & MSDOSFSMNT_VERSIONED) == 0) {
args->version = 1;
args->dirmask = args->mask;
}
/*
* Reset GMT offset for pre-v3 mount structure args.
*/
if (args->version < 3)
args->gmtoff = 0;
/*
* If updating, check whether changing from read-only to
* read/write; if there is no device name, that's all we do.
*/
if (mp->mnt_flag & MNT_UPDATE) {
pmp = VFSTOMSDOSFS(mp);
error = 0;
if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
(mp->mnt_flag & MNT_RDONLY)) {
flags = WRITECLOSE;
if (mp->mnt_flag & MNT_FORCE)
flags |= FORCECLOSE;
error = vflush(mp, NULLVP, flags);
}
if (!error && (mp->mnt_flag & MNT_RELOAD))
/* not yet implemented */
error = EOPNOTSUPP;
if (error) {
DPRINTF("vflush %d", error);
return (error);
}
if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
(mp->mnt_iflag & IMNT_WANTRDWR)) {
/*
* If upgrade to read-write by non-root, then verify
* that user has necessary permissions on the device.
*
* Permission to update a mount is checked higher, so
* here we presume updating the mount is okay (for
* example, as far as securelevel goes) which leaves us
* with the normal check.
*/
devvp = pmp->pm_devvp;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = kauth_authorize_system(l->l_cred,
KAUTH_SYSTEM_MOUNT, KAUTH_REQ_SYSTEM_MOUNT_DEVICE,
mp, devvp, KAUTH_ARG(VREAD | VWRITE));
VOP_UNLOCK(devvp);
DPRINTF("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d", error);
if (error)
return (error);
pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
}
if (args->fspec == NULL) {
DPRINTF("missing fspec");
return EINVAL;
}
}
/*
* Not an update, or updating the name: look up the name
* and verify that it refers to a sensible block device.
*/
error = namei_simple_user(args->fspec,
NSM_FOLLOW_NOEMULROOT, &devvp);
if (error != 0) {
DPRINTF("namei %d", error);
return (error);
}
if (devvp->v_type != VBLK) {
DPRINTF("not block");
vrele(devvp);
return (ENOTBLK);
}
if (bdevsw_lookup(devvp->v_rdev) == NULL) {
DPRINTF("no block switch");
vrele(devvp);
return (ENXIO);
}
/*
* If mount by non-root, then verify that user has necessary
* permissions on the device.
*/
accessmode = VREAD;
if ((mp->mnt_flag & MNT_RDONLY) == 0)
accessmode |= VWRITE;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp, KAUTH_ARG(accessmode));
VOP_UNLOCK(devvp);
if (error) {
DPRINTF("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d", error);
vrele(devvp);
return (error);
}
if ((mp->mnt_flag & MNT_UPDATE) == 0) {
int xflags;
if (mp->mnt_flag & MNT_RDONLY)
xflags = FREAD;
else
xflags = FREAD|FWRITE;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_OPEN(devvp, xflags, FSCRED);
VOP_UNLOCK(devvp);
if (error) {
DPRINTF("VOP_OPEN %d", error);
goto fail;
}
error = msdosfs_mountfs(devvp, mp, l, args);
if (error) {
DPRINTF("msdosfs_mountfs %d", error);
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
(void) VOP_CLOSE(devvp, xflags, NOCRED);
VOP_UNLOCK(devvp);
goto fail;
}
#ifdef MSDOSFS_DEBUG /* only needed for the printf below */
pmp = VFSTOMSDOSFS(mp);
#endif
} else {
vrele(devvp);
if (devvp != pmp->pm_devvp) {
DPRINTF("devvp %p pmp %p", devvp, pmp->pm_devvp);
return (EINVAL); /* needs translation */
}
}
if ((error = update_mp(mp, args)) != 0) {
msdosfs_unmount(mp, MNT_FORCE);
DPRINTF("update_mp %d", error);
return error;
}
#ifdef MSDOSFS_DEBUG
printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
#endif
return set_statvfs_info(path, UIO_USERSPACE, args->fspec, UIO_USERSPACE,
mp->mnt_op->vfs_name, mp, l);
fail:
vrele(devvp);
return (error);
}
int
msdosfs_mountfs(struct vnode *devvp, struct mount *mp, struct lwp *l, struct msdosfs_args *argp)
{
struct msdosfsmount *pmp;
struct buf *bp;
dev_t dev = devvp->v_rdev;
union bootsector *bsp;
struct byte_bpb33 *b33;
struct byte_bpb50 *b50;
struct byte_bpb710 *b710;
uint8_t SecPerClust;
int ronly, error, BlkPerSec;
uint64_t psize;
unsigned secsize;
u_long fatbytes, fatblocksecs;
/* Flush out any old buffers remaining from a previous use. */
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = vinvalbuf(devvp, V_SAVE, l->l_cred, l, 0, 0);
VOP_UNLOCK(devvp);
if (error)
return (error);
ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
bp = NULL; /* both used in error_exit */
pmp = NULL;
error = getdisksize(devvp, &psize, &secsize);
if (error) {
if (argp->flags & MSDOSFSMNT_GEMDOSFS)
goto error_exit;
/* ok, so it failed. we most likely don't need the info */
secsize = DEV_BSIZE;
psize = 0;
error = 0;
}
if (secsize < DEV_BSIZE) {
DPRINTF("Invalid block secsize (%d < DEV_BSIZE)", secsize);
error = EINVAL;
goto error_exit;
}
if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
if (secsize != GEMDOSFS_BSIZE) {
DPRINTF("Invalid block secsize %d for GEMDOS", secsize);
error = EINVAL;
goto error_exit;
}
}
/*
* Read the boot sector of the filesystem, and then check the
* boot signature. If not a dos boot sector then error out.
*/
if (secsize < sizeof(*b50)) {
DPRINTF("50 bootsec %u\n", secsize);
error = EINVAL;
goto error_exit;
}
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 0
/*
* Some FAT partition, for example Raspberry Pi Pico's
* USB mass storage, does not have exptected BOOTSIGs.
* According to FreeBSD's comment, some PC-9800/9821
* FAT floppy disks have similar problems.
*/
if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
|| bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
DPRINTF("bootsig0 %d bootsig1 %d",
bsp->bs50.bsBootSectSig0,
bsp->bs50.bsBootSectSig1);
error = EINVAL;
goto error_exit;
}
}
#endif
pmp = malloc(sizeof(*pmp), M_MSDOSFSMNT, M_WAITOK|M_ZERO);
pmp->pm_mountp = mp;
/*
* 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;
if (pmp->pm_Sectors == 0) {
pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
} else {
if (secsize < sizeof(*b33)) {
DPRINTF("33 bootsec %u\n", secsize);
error = EINVAL;
goto error_exit;
}
pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
pmp->pm_HugeSectors = pmp->pm_Sectors;
}
/*
* Sanity checks, from the FAT specification:
* - sectors per cluster: >= 1, power of 2
* - logical sector size: >= 1, power of 2
* - cluster size: <= max FS block size
* - number of sectors: >= 1
*/
if ((SecPerClust == 0) || !powerof2(SecPerClust) ||
(pmp->pm_BytesPerSec == 0) || !powerof2(pmp->pm_BytesPerSec) ||
(SecPerClust * pmp->pm_BytesPerSec > MAXBSIZE) ||
(pmp->pm_HugeSectors == 0)) {
DPRINTF("consistency checks");
error = EINVAL;
goto error_exit;
}
if (!(argp->flags & MSDOSFSMNT_GEMDOSFS) &&
(pmp->pm_SecPerTrack > 63)) {
DPRINTF("SecPerTrack %d", pmp->pm_SecPerTrack);
error = EINVAL;
goto error_exit;
}
if (pmp->pm_RootDirEnts == 0) {
if (secsize < sizeof(*b710)) {
DPRINTF("710 bootsec %u\n", secsize);
error = EINVAL;
goto error_exit;
}
unsigned short FSVers = getushort(b710->bpbFSVers);
unsigned short ExtFlags = getushort(b710->bpbExtFlags);
/*
* 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 || FSVers) {
DPRINTF("Sectors %d FATsecs %lu FSVers %d",
pmp->pm_Sectors, pmp->pm_FATsecs, FSVers);
error = EINVAL;
goto error_exit;
}
pmp->pm_fatmask = FAT32_MASK;
pmp->pm_fatmult = 4;
pmp->pm_fatdiv = 1;
pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
/* Mirroring is enabled if the FATMIRROR bit is not set. */
if ((ExtFlags & FATMIRROR) == 0)
pmp->pm_flags |= MSDOSFS_FATMIRROR;
else
pmp->pm_curfat = ExtFlags & FATNUM;
} else
pmp->pm_flags |= MSDOSFS_FATMIRROR;
if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
if (FAT32(pmp)) {
/* GEMDOS doesn't know FAT32. */
DPRINTF("FAT32 for GEMDOS");
error = EINVAL;
goto error_exit;
}
/*
* Check a few values (could do some more):
* - logical sector size: >= block size
* - number of sectors: <= size of partition
*/
if ((pmp->pm_BytesPerSec < GEMDOSFS_BSIZE) ||
(pmp->pm_HugeSectors *
(pmp->pm_BytesPerSec / GEMDOSFS_BSIZE) > psize)) {
DPRINTF("consistency checks for GEMDOS");
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.
*/
BlkPerSec = pmp->pm_BytesPerSec / GEMDOSFS_BSIZE;
pmp->pm_BytesPerSec = GEMDOSFS_BSIZE;
pmp->pm_HugeSectors *= BlkPerSec;
pmp->pm_HiddenSects *= BlkPerSec;
pmp->pm_ResSectors *= BlkPerSec;
pmp->pm_Sectors *= BlkPerSec;
pmp->pm_FATsecs *= BlkPerSec;
SecPerClust *= BlkPerSec;
}
/* Check that fs has nonzero FAT size */
if (pmp->pm_FATsecs == 0) {
DPRINTF("FATsecs is 0");
error = EINVAL;
goto error_exit;
}
pmp->pm_fatblk = pmp->pm_ResSectors;
if (FAT32(pmp)) {
if (secsize < sizeof(*b710)) {
DPRINTF("710 bootsec %u\n", secsize);
error = EINVAL;
goto error_exit;
}
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 (argp->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;
}
}
/* validate cluster count against FAT */
if ((pmp->pm_maxcluster & pmp->pm_fatmask) != pmp->pm_maxcluster) {
DPRINTF("maxcluster %lu outside of mask %#lx\n",
pmp->pm_maxcluster, pmp->pm_fatmask);
error = EINVAL;
goto error_exit;
}
/* validate FAT size */
fatbytes = (pmp->pm_maxcluster+1) * pmp->pm_fatmult / pmp->pm_fatdiv;
fatblocksecs = howmany(fatbytes, pmp->pm_BytesPerSec);
if (pmp->pm_FATsecs < fatblocksecs) {
DPRINTF("FATsecs %lu < real %lu\n", pmp->pm_FATsecs,
fatblocksecs);
error = EINVAL;
goto error_exit;
}
if (FAT12(pmp)) {
/*
* limit block size to what is needed to read a FAT block
* to not exceed MAXBSIZE
*/
pmp->pm_fatblocksec = uimin(3, fatblocksecs);
pmp->pm_fatblocksize = pmp->pm_fatblocksec
* 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;
/*
* Check for valid cluster size
* must be a power of 2
*/
if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
DPRINTF("bpcluster %lu cnshift %lu", pmp->pm_bpcluster,
pmp->pm_cnshift);
error = EINVAL;
goto error_exit;
}
/*
* Cluster size must be within limit of MAXBSIZE.
* Many FAT filesystems will not have clusters larger than
* 32KiB due to limits in Windows versions before Vista.
*/
if (pmp->pm_bpcluster > MAXBSIZE) {
DPRINTF("bpcluster %lu > MAXBSIZE %d",
pmp->pm_bpcluster, MAXBSIZE);
error = EINVAL;
goto error_exit;
}
/*
* Release the bootsector buffer.
*/
brelse(bp, BC_AGE);
bp = NULL;
/*
* Check FSInfo.
*/
if (pmp->pm_fsinfo) {
struct fsinfo *fp;
const int rdsz = roundup(sizeof(*fp), pmp->pm_BytesPerSec);
/*
* 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?
*/
if ((error = bread(devvp, de_bn2kb(pmp, pmp->pm_fsinfo),
rdsz, 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 = malloc(((pmp->pm_maxcluster + N_INUSEBITS)
/ N_INUSEBITS)
* sizeof(*pmp->pm_inusemap),
M_MSDOSFSFAT, M_WAITOK);
/*
* fillinusemap() needs pm_devvp.
*/
pmp->pm_dev = dev;
pmp->pm_devvp = devvp;
/*
* Have the inuse map filled in.
*/
if ((error = msdosfs_fillinusemap(pmp)) != 0) {
DPRINTF("fillinusemap %d", error);
goto error_exit;
}
/*
* If they want FAT updates to be synchronous then let them suffer
* the performance degradation in exchange for the on disk copy of
* the FAT being correct just about all the time. I suppose this
* would be a good thing to turn on if the kernel is still flakey.
*/
if (mp->mnt_flag & MNT_SYNCHRONOUS)
pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
/*
* Finish up.
*/
if (ronly)
pmp->pm_flags |= MSDOSFSMNT_RONLY;
else
pmp->pm_fmod = 1;
mp->mnt_data = pmp;
mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_MSDOS);
mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp);
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_iflag |= IMNT_SHRLOOKUP;
mp->mnt_dev_bshift = pmp->pm_bnshift;
mp->mnt_fs_bshift = pmp->pm_cnshift;
/*
* 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.
*/
spec_node_setmountedfs(devvp, mp);
return (0);
error_exit:
if (bp)
brelse(bp, BC_AGE);
if (pmp) {
if (pmp->pm_inusemap)
free(pmp->pm_inusemap, M_MSDOSFSFAT);
free(pmp, M_MSDOSFSMNT);
mp->mnt_data = NULL;
}
return (error);
}
int
msdosfs_start(struct mount *mp, int flags)
{
return (0);
}
/*
* Unmount the filesystem described by mp.
*/
int
msdosfs_unmount(struct mount *mp, int mntflags)
{
struct msdosfsmount *pmp;
int error, flags;
flags = 0;
if (mntflags & MNT_FORCE)
flags |= FORCECLOSE;
if ((error = vflush(mp, NULLVP, flags)) != 0)
return (error);
pmp = VFSTOMSDOSFS(mp);
if (pmp->pm_devvp->v_type != VBAD)
spec_node_setmountedfs(pmp->pm_devvp, NULL);
#ifdef MSDOSFS_DEBUG
{
struct vnode *vp = pmp->pm_devvp;
printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
printf("flag %08x, usecount %d, writecount %d, holdcnt %d\n",
vp->v_vflag | vp->v_iflag | vp->v_uflag, vrefcnt(vp),
vp->v_writecount, vp->v_holdcnt);
printf("mount %p, op %p\n",
vp->v_mount, vp->v_op);
printf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
vp->v_cleanblkhd.lh_first,
vp->v_dirtyblkhd.lh_first,
vp->v_numoutput, vp->v_type);
printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
vp->v_socket, vp->v_tag,
((u_int *)vp->v_data)[0],
((u_int *)vp->v_data)[1]);
}
#endif
vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
(void) VOP_CLOSE(pmp->pm_devvp,
pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD|FWRITE, NOCRED);
vput(pmp->pm_devvp);
msdosfs_fh_destroy(pmp);
free(pmp->pm_inusemap, M_MSDOSFSFAT);
free(pmp, M_MSDOSFSMNT);
mp->mnt_data = NULL;
mp->mnt_flag &= ~MNT_LOCAL;
return (0);
}
int
msdosfs_root(struct mount *mp, int lktype, struct vnode **vpp)
{
struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
int error;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
#endif
if ((error = msdosfs_deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS,
vpp)) != 0)
return error;
error = vn_lock(*vpp, lktype);
if (error) {
vrele(*vpp);
*vpp = NULL;
return error;
}
return 0;
}
int
msdosfs_statvfs(struct mount *mp, struct statvfs *sbp)
{
struct msdosfsmount *pmp;
pmp = VFSTOMSDOSFS(mp);
sbp->f_bsize = pmp->pm_bpcluster;
sbp->f_frsize = sbp->f_bsize;
sbp->f_iosize = pmp->pm_bpcluster;
sbp->f_blocks = pmp->pm_nmbrofclusters;
sbp->f_bfree = pmp->pm_freeclustercount;
sbp->f_bavail = pmp->pm_freeclustercount;
sbp->f_bresvd = 0;
sbp->f_files = pmp->pm_RootDirEnts; /* XXX */
sbp->f_ffree = 0; /* what to put in here? */
sbp->f_favail = 0; /* what to put in here? */
sbp->f_fresvd = 0;
copy_statvfs_info(sbp, mp);
return (0);
}
struct msdosfs_sync_ctx {
int waitfor;
};
static bool
msdosfs_sync_selector(void *cl, struct vnode *vp)
{
struct msdosfs_sync_ctx *c = cl;
struct denode *dep;
KASSERT(mutex_owned(vp->v_interlock));
dep = VTODE(vp);
if (c->waitfor == MNT_LAZY || vp->v_type == VNON ||
dep == NULL || (((dep->de_flag &
(DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0) &&
(LIST_EMPTY(&vp->v_dirtyblkhd) &&
(vp->v_iflag & VI_ONWORKLST) == 0)))
return false;
return true;
}
int
msdosfs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
{
struct vnode *vp;
struct vnode_iterator *marker;
struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
int error, allerror = 0;
struct msdosfs_sync_ctx ctx;
/*
* If we ever switch to not updating all of the FATs all the time,
* this would be the place to update them from the first one.
*/
if (pmp->pm_fmod != 0) {
if (pmp->pm_flags & MSDOSFSMNT_RONLY)
panic("msdosfs_sync: rofs mod");
else {
/* update FATs here */
}
}
/*
* Write back each (modified) denode.
*/
vfs_vnode_iterator_init(mp, &marker);
ctx.waitfor = waitfor;
while ((vp = vfs_vnode_iterator_next(marker, msdosfs_sync_selector,
&ctx)))
{
error = vn_lock(vp, LK_EXCLUSIVE);
if (error) {
vrele(vp);
continue;
}
if ((error = VOP_FSYNC(vp, cred,
waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
allerror = error;
vput(vp);
}
vfs_vnode_iterator_destroy(marker);
/*
* Force stale file system control information to be flushed.
*/
vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
if ((error = VOP_FSYNC(pmp->pm_devvp, cred,
waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
allerror = error;
VOP_UNLOCK(pmp->pm_devvp);
return (allerror);
}
int
msdosfs_fhtovp(struct mount *mp, struct fid *fhp, int lktype, struct vnode **vpp)
{
struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
struct defid defh;
uint32_t gen;
int error;
if (fhp->fid_len != sizeof(struct defid)) {
DPRINTF("fid_len %d %zd", fhp->fid_len, sizeof(struct defid));
return EINVAL;
}
memcpy(&defh, fhp, sizeof(defh));
error = msdosfs_fh_lookup(pmp, defh.defid_dirclust, defh.defid_dirofs,
&gen);
if (error == 0 && gen != defh.defid_gen)
error = ESTALE;
if (error) {
*vpp = NULLVP;
return error;
}
error = msdosfs_deget(pmp, defh.defid_dirclust, defh.defid_dirofs, vpp);
if (error) {
DPRINTF("deget %d", error);
*vpp = NULLVP;
return error;
}
error = vn_lock(*vpp, lktype);
if (error) {
vrele(*vpp);
*vpp = NULLVP;
return error;
}
return 0;
}
int
msdosfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
{
struct msdosfsmount *pmp = VFSTOMSDOSFS(vp->v_mount);
struct denode *dep;
struct defid defh;
int error;
if (*fh_size < sizeof(struct defid)) {
*fh_size = sizeof(struct defid);
return E2BIG;
}
*fh_size = sizeof(struct defid);
dep = VTODE(vp);
memset(&defh, 0, sizeof(defh));
defh.defid_len = sizeof(struct defid);
defh.defid_dirclust = dep->de_dirclust;
defh.defid_dirofs = dep->de_diroffset;
error = msdosfs_fh_enter(pmp, dep->de_dirclust, dep->de_diroffset,
&defh.defid_gen);
if (error == 0)
memcpy(fhp, &defh, sizeof(defh));
return error;
}
int
msdosfs_vget(struct mount *mp, ino_t ino, int lktype,
struct vnode **vpp)
{
return (EOPNOTSUPP);
}
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