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freebsd-nq/sys/fs/msdosfs/msdosfs_vfsops.c
Konstantin Belousov bb7ca8229d Do not update the fsinfo block on each update of any fat block, this 
is excessive. Postpone the flush of the fsinfo to VFS_SYNC(),
remembering the need for update with the flag MSDOSFS_FSIMOD, stored
in pm_flags.

FAT32 specification describes both FSI_Free_Count and FSI_Nxt_Free as
the advisory hints, not requiring them to be correct.

Based on the patch from bde, modified by me.

Reviewed by: bde
MFC after:   2 weeks
2013-02-17 20:35:54 +00:00

1032 lines
28 KiB
C
Raw Blame History

/* $FreeBSD$ */
/* $NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws 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/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/iconv.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/stat.h>
#include <sys/vnode.h>
#include <geom/geom.h>
#include <geom/geom_vfs.h>
#include <fs/msdosfs/bootsect.h>
#include <fs/msdosfs/bpb.h>
#include <fs/msdosfs/direntry.h>
#include <fs/msdosfs/denode.h>
#include <fs/msdosfs/fat.h>
#include <fs/msdosfs/msdosfsmount.h>
static const char msdosfs_lock_msg[] = "fatlk";
/* Mount options that we support. */
static const char *msdosfs_opts[] = {
"async", "noatime", "noclusterr", "noclusterw",
"export", "force", "from", "sync",
"cs_dos", "cs_local", "cs_win", "dirmask",
"gid", "kiconv", "large", "longname",
"longnames", "mask", "shortname", "shortnames",
"uid", "win95", "nowin95",
NULL
};
#if 1 /*def PC98*/
/*
* XXX - The boot signature formatted by NEC PC-98 DOS looks like a
* garbage or a random value :-{
* If you want to use that broken-signatured media, define the
* following symbol even though PC/AT.
* (ex. mount PC-98 DOS formatted FD on PC/AT)
*/
#define MSDOSFS_NOCHECKSIG
#endif
MALLOC_DEFINE(M_MSDOSFSMNT, "msdosfs_mount", "MSDOSFS mount structure");
static MALLOC_DEFINE(M_MSDOSFSFAT, "msdosfs_fat", "MSDOSFS file allocation table");
struct iconv_functions *msdosfs_iconv;
static int update_mp(struct mount *mp, struct thread *td);
static int mountmsdosfs(struct vnode *devvp, struct mount *mp);
static vfs_fhtovp_t msdosfs_fhtovp;
static vfs_mount_t msdosfs_mount;
static vfs_root_t msdosfs_root;
static vfs_statfs_t msdosfs_statfs;
static vfs_sync_t msdosfs_sync;
static vfs_unmount_t msdosfs_unmount;
/* Maximum length of a character set name (arbitrary). */
#define MAXCSLEN 64
static int
update_mp(struct mount *mp, struct thread *td)
{
struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
void *dos, *win, *local;
int error, v;
if (!vfs_getopt(mp->mnt_optnew, "kiconv", NULL, NULL)) {
if (msdosfs_iconv != NULL) {
error = vfs_getopt(mp->mnt_optnew,
"cs_win", &win, NULL);
if (!error)
error = vfs_getopt(mp->mnt_optnew,
"cs_local", &local, NULL);
if (!error)
error = vfs_getopt(mp->mnt_optnew,
"cs_dos", &dos, NULL);
if (!error) {
msdosfs_iconv->open(win, local, &pmp->pm_u2w);
msdosfs_iconv->open(local, win, &pmp->pm_w2u);
msdosfs_iconv->open(dos, local, &pmp->pm_u2d);
msdosfs_iconv->open(local, dos, &pmp->pm_d2u);
}
if (error != 0)
return (error);
} else {
pmp->pm_w2u = NULL;
pmp->pm_u2w = NULL;
pmp->pm_d2u = NULL;
pmp->pm_u2d = NULL;
}
}
if (vfs_scanopt(mp->mnt_optnew, "gid", "%d", &v) == 1)
pmp->pm_gid = v;
if (vfs_scanopt(mp->mnt_optnew, "uid", "%d", &v) == 1)
pmp->pm_uid = v;
if (vfs_scanopt(mp->mnt_optnew, "mask", "%d", &v) == 1)
pmp->pm_mask = v & ALLPERMS;
if (vfs_scanopt(mp->mnt_optnew, "dirmask", "%d", &v) == 1)
pmp->pm_dirmask = v & ALLPERMS;
vfs_flagopt(mp->mnt_optnew, "shortname",
&pmp->pm_flags, MSDOSFSMNT_SHORTNAME);
vfs_flagopt(mp->mnt_optnew, "shortnames",
&pmp->pm_flags, MSDOSFSMNT_SHORTNAME);
vfs_flagopt(mp->mnt_optnew, "longname",
&pmp->pm_flags, MSDOSFSMNT_LONGNAME);
vfs_flagopt(mp->mnt_optnew, "longnames",
&pmp->pm_flags, MSDOSFSMNT_LONGNAME);
vfs_flagopt(mp->mnt_optnew, "kiconv",
&pmp->pm_flags, MSDOSFSMNT_KICONV);
if (vfs_getopt(mp->mnt_optnew, "nowin95", NULL, NULL) == 0)
pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
else
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 *rootvp;
/*
* Try to divine whether to support Win'95 long filenames
*/
if (FAT32(pmp))
pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
else {
if ((error =
msdosfs_root(mp, LK_EXCLUSIVE, &rootvp)) != 0)
return error;
pmp->pm_flags |= findwin95(VTODE(rootvp)) ?
MSDOSFSMNT_LONGNAME : MSDOSFSMNT_SHORTNAME;
vput(rootvp);
}
}
return 0;
}
static int
msdosfs_cmount(struct mntarg *ma, void *data, uint64_t flags)
{
struct msdosfs_args args;
struct export_args exp;
int error;
if (data == NULL)
return (EINVAL);
error = copyin(data, &args, sizeof args);
if (error)
return (error);
vfs_oexport_conv(&args.export, &exp);
ma = mount_argsu(ma, "from", args.fspec, MAXPATHLEN);
ma = mount_arg(ma, "export", &exp, sizeof(exp));
ma = mount_argf(ma, "uid", "%d", args.uid);
ma = mount_argf(ma, "gid", "%d", args.gid);
ma = mount_argf(ma, "mask", "%d", args.mask);
ma = mount_argf(ma, "dirmask", "%d", args.dirmask);
ma = mount_argb(ma, args.flags & MSDOSFSMNT_SHORTNAME, "noshortname");
ma = mount_argb(ma, args.flags & MSDOSFSMNT_LONGNAME, "nolongname");
ma = mount_argb(ma, !(args.flags & MSDOSFSMNT_NOWIN95), "nowin95");
ma = mount_argb(ma, args.flags & MSDOSFSMNT_KICONV, "nokiconv");
ma = mount_argsu(ma, "cs_win", args.cs_win, MAXCSLEN);
ma = mount_argsu(ma, "cs_dos", args.cs_dos, MAXCSLEN);
ma = mount_argsu(ma, "cs_local", args.cs_local, MAXCSLEN);
error = kernel_mount(ma, flags);
return (error);
}
/*
* 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.
*/
static int
msdosfs_mount(struct mount *mp)
{
struct vnode *devvp; /* vnode for blk device to mount */
struct thread *td;
/* msdosfs specific mount control block */
struct msdosfsmount *pmp = NULL;
struct nameidata ndp;
int error, flags;
accmode_t accmode;
char *from;
td = curthread;
if (vfs_filteropt(mp->mnt_optnew, msdosfs_opts))
return (EINVAL);
/*
* 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);
if (vfs_flagopt(mp->mnt_optnew, "export", NULL, 0)) {
/*
* Forbid export requests if filesystem has
* MSDOSFS_LARGEFS flag set.
*/
if ((pmp->pm_flags & MSDOSFS_LARGEFS) != 0) {
vfs_mount_error(mp,
"MSDOSFS_LARGEFS flag set, cannot export");
return (EOPNOTSUPP);
}
}
if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
error = VFS_SYNC(mp, MNT_WAIT);
if (error)
return (error);
flags = WRITECLOSE;
if (mp->mnt_flag & MNT_FORCE)
flags |= FORCECLOSE;
error = vflush(mp, 0, flags, td);
if (error)
return (error);
/*
* Now the volume is clean. Mark it so while the
* device is still rw.
*/
error = markvoldirty(pmp, 0);
if (error) {
(void)markvoldirty(pmp, 1);
return (error);
}
/* Downgrade the device from rw to ro. */
DROP_GIANT();
g_topology_lock();
error = g_access(pmp->pm_cp, 0, -1, 0);
g_topology_unlock();
PICKUP_GIANT();
if (error) {
(void)markvoldirty(pmp, 1);
return (error);
}
/*
* Backing out after an error was painful in the
* above. Now we are committed to succeeding.
*/
pmp->pm_fmod = 0;
pmp->pm_flags |= MSDOSFSMNT_RONLY;
MNT_ILOCK(mp);
mp->mnt_flag |= MNT_RDONLY;
MNT_IUNLOCK(mp);
} else if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
/*
* If upgrade to read-write by non-root, then verify
* that user has necessary permissions on the device.
*/
devvp = pmp->pm_devvp;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_ACCESS(devvp, VREAD | VWRITE,
td->td_ucred, td);
if (error)
error = priv_check(td, PRIV_VFS_MOUNT_PERM);
if (error) {
VOP_UNLOCK(devvp, 0);
return (error);
}
VOP_UNLOCK(devvp, 0);
DROP_GIANT();
g_topology_lock();
error = g_access(pmp->pm_cp, 0, 1, 0);
g_topology_unlock();
PICKUP_GIANT();
if (error)
return (error);
pmp->pm_fmod = 1;
pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
MNT_ILOCK(mp);
mp->mnt_flag &= ~MNT_RDONLY;
MNT_IUNLOCK(mp);
/* Now that the volume is modifiable, mark it dirty. */
error = markvoldirty(pmp, 1);
if (error)
return (error);
}
}
/*
* Not an update, or updating the name: look up the name
* and verify that it refers to a sensible disk device.
*/
if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL))
return (EINVAL);
NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, from, td);
error = namei(&ndp);
if (error)
return (error);
devvp = ndp.ni_vp;
NDFREE(&ndp, NDF_ONLY_PNBUF);
if (!vn_isdisk(devvp, &error)) {
vput(devvp);
return (error);
}
/*
* If mount by non-root, then verify that user has necessary
* permissions on the device.
*/
accmode = VREAD;
if ((mp->mnt_flag & MNT_RDONLY) == 0)
accmode |= VWRITE;
error = VOP_ACCESS(devvp, accmode, td->td_ucred, td);
if (error)
error = priv_check(td, PRIV_VFS_MOUNT_PERM);
if (error) {
vput(devvp);
return (error);
}
if ((mp->mnt_flag & MNT_UPDATE) == 0) {
error = mountmsdosfs(devvp, mp);
#ifdef MSDOSFS_DEBUG /* only needed for the printf below */
pmp = VFSTOMSDOSFS(mp);
#endif
} else {
vput(devvp);
if (devvp != pmp->pm_devvp)
return (EINVAL); /* XXX needs translation */
}
if (error) {
vrele(devvp);
return (error);
}
error = update_mp(mp, td);
if (error) {
if ((mp->mnt_flag & MNT_UPDATE) == 0)
msdosfs_unmount(mp, MNT_FORCE);
return error;
}
if (devvp->v_type == VCHR && devvp->v_rdev != NULL)
devvp->v_rdev->si_mountpt = mp;
vfs_mountedfrom(mp, from);
#ifdef MSDOSFS_DEBUG
printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
#endif
return (0);
}
static int
mountmsdosfs(struct vnode *devvp, struct mount *mp)
{
struct msdosfsmount *pmp;
struct buf *bp;
struct cdev *dev;
union bootsector *bsp;
struct byte_bpb33 *b33;
struct byte_bpb50 *b50;
struct byte_bpb710 *b710;
u_int8_t SecPerClust;
u_long clusters;
int ronly, error;
struct g_consumer *cp;
struct bufobj *bo;
bp = NULL; /* This and pmp both used in error_exit. */
pmp = NULL;
ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
dev = devvp->v_rdev;
dev_ref(dev);
DROP_GIANT();
g_topology_lock();
error = g_vfs_open(devvp, &cp, "msdosfs", ronly ? 0 : 1);
g_topology_unlock();
PICKUP_GIANT();
VOP_UNLOCK(devvp, 0);
if (error)
goto error_exit;
bo = &devvp->v_bufobj;
/*
* Read the boot sector of the filesystem, and then check the
* boot signature. If not a dos boot sector then error out.
*
* NOTE: 8192 is a magic size that works for ffs.
*/
error = bread(devvp, 0, 8192, NOCRED, &bp);
if (error)
goto error_exit;
bp->b_flags |= B_AGE;
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;
#ifndef MSDOSFS_NOCHECKSIG
if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
|| bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
error = EINVAL;
goto error_exit;
}
#endif
pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK | M_ZERO);
pmp->pm_mountp = mp;
pmp->pm_cp = cp;
pmp->pm_bo = bo;
lockinit(&pmp->pm_fatlock, 0, msdosfs_lock_msg, 0, 0);
/*
* Initialize ownerships and permissions, since nothing else will
* initialize them iff we are mounting root.
*/
pmp->pm_uid = UID_ROOT;
pmp->pm_gid = GID_WHEEL;
pmp->pm_mask = pmp->pm_dirmask = S_IXUSR | S_IXGRP | S_IXOTH |
S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR;
/*
* Experimental support for large MS-DOS filesystems.
* WARNING: This uses at least 32 bytes of kernel memory (which is not
* reclaimed until the FS is unmounted) for each file on disk to map
* between the 32-bit inode numbers used by VFS and the 64-bit
* pseudo-inode numbers used internally by msdosfs. This is only
* safe to use in certain controlled situations (e.g. read-only FS
* with less than 1 million files).
* Since the mappings do not persist across unmounts (or reboots), these
* filesystems are not suitable for exporting through NFS, or any other
* application that requires fixed inode numbers.
*/
vfs_flagopt(mp->mnt_optnew, "large", &pmp->pm_flags, MSDOSFS_LARGEFS);
/*
* 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);
if (pmp->pm_BytesPerSec < DEV_BSIZE) {
error = EINVAL;
goto error_exit;
}
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;
/* calculate the ratio of sector size to DEV_BSIZE */
pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
/*
* We don't check pm_Heads nor pm_SecPerTrack, because
* these may not be set for EFI file systems. We don't
* use these anyway, so we're unaffected if they are
* invalid.
*/
if (!pmp->pm_BytesPerSec || !SecPerClust) {
error = EINVAL;
goto error_exit;
}
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_flags & MSDOSFS_LARGEFS)) {
if (pmp->pm_HugeSectors > 0xffffffff /
(pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
/*
* We cannot deal currently with this size of disk
* due to fileid limitations (see msdosfs_getattr and
* msdosfs_readdir)
*/
error = EINVAL;
vfs_mount_error(mp,
"Disk too big, try '-o large' mount option");
goto error_exit;
}
}
if (pmp->pm_RootDirEnts == 0) {
if (pmp->pm_FATsecs
|| getushort(b710->bpbFSVers)) {
error = EINVAL;
#ifdef MSDOSFS_DEBUG
printf("mountmsdosfs(): bad FAT32 filesystem\n");
#endif
goto error_exit;
}
pmp->pm_fatmask = FAT32_MASK;
pmp->pm_fatmult = 4;
pmp->pm_fatdiv = 1;
pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
if (getushort(b710->bpbExtFlags) & FATMIRROR)
pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
else
pmp->pm_flags |= MSDOSFS_FATMIRROR;
} else
pmp->pm_flags |= MSDOSFS_FATMIRROR;
/*
* 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
* - number of FAT sectors: >= 1
*/
if ( (SecPerClust == 0)
|| (SecPerClust & (SecPerClust - 1))
|| (pmp->pm_BytesPerSec < DEV_BSIZE)
|| (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
|| (pmp->pm_HugeSectors == 0)
|| (pmp->pm_FATsecs == 0)
|| (SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE)
) {
error = EINVAL;
goto error_exit;
}
pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
pmp->pm_FATsecs *= pmp->pm_BlkPerSec;
SecPerClust *= pmp->pm_BlkPerSec;
pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
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) * pmp->pm_BlkPerSec;
} else {
pmp->pm_rootdirblk = pmp->pm_fatblk +
(pmp->pm_FATs * pmp->pm_FATsecs);
pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
+ DEV_BSIZE - 1)
/ DEV_BSIZE; /* in blocks */
pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
}
pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
SecPerClust + 1;
pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
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;
}
}
clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
if (pmp->pm_maxcluster >= clusters) {
#ifdef MSDOSFS_DEBUG
printf("Warning: number of clusters (%ld) exceeds FAT "
"capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
#endif
pmp->pm_maxcluster = clusters - 1;
}
if (FAT12(pmp))
pmp->pm_fatblocksize = 3 * 512;
else
pmp->pm_fatblocksize = PAGE_SIZE;
pmp->pm_fatblocksize = roundup(pmp->pm_fatblocksize,
pmp->pm_BytesPerSec);
pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
/*
* Compute mask and shift value for isolating cluster relative byte
* offsets and cluster numbers from a file offset.
*/
pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
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)) {
error = EINVAL;
goto error_exit;
}
/*
* Release the bootsector buffer.
*/
brelse(bp);
bp = NULL;
/*
* Check the fsinfo sector if we have one. Silently fix up our
* in-core copy of fp->fsinxtfree if it is unknown (0xffffffff)
* or too large. Ignore fp->fsinfree for now, since we need to
* read the entire FAT anyway to fill the inuse map.
*/
if (pmp->pm_fsinfo) {
struct fsinfo *fp;
if ((error = bread(devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec,
NOCRED, &bp)) != 0)
goto error_exit;
fp = (struct fsinfo *)bp->b_data;
if (!bcmp(fp->fsisig1, "RRaA", 4)
&& !bcmp(fp->fsisig2, "rrAa", 4)
&& !bcmp(fp->fsisig3, "\0\0\125\252", 4)) {
pmp->pm_nxtfree = getulong(fp->fsinxtfree);
if (pmp->pm_nxtfree > pmp->pm_maxcluster)
pmp->pm_nxtfree = CLUST_FIRST;
} else
pmp->pm_fsinfo = 0;
brelse(bp);
bp = NULL;
}
/*
* Finish initializing pmp->pm_nxtfree (just in case the first few
* sectors aren't properly reserved in the FAT). This completes
* the fixup for fp->fsinxtfree, and fixes up the zero-initialized
* value if there is no fsinfo. We will use pmp->pm_nxtfree
* internally even if there is no fsinfo.
*/
if (pmp->pm_nxtfree < CLUST_FIRST)
pmp->pm_nxtfree = CLUST_FIRST;
/*
* Allocate memory for the bitmap of allocated clusters, and then
* fill it in.
*/
pmp->pm_inusemap = malloc(howmany(pmp->pm_maxcluster + 1, N_INUSEBITS)
* sizeof(*pmp->pm_inusemap),
M_MSDOSFSFAT, M_WAITOK);
/*
* fillinusemap() needs pm_devvp.
*/
pmp->pm_devvp = devvp;
pmp->pm_dev = dev;
/*
* Have the inuse map filled in.
*/
MSDOSFS_LOCK_MP(pmp);
error = fillinusemap(pmp);
MSDOSFS_UNLOCK_MP(pmp);
if (error != 0)
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 {
if ((error = markvoldirty(pmp, 1)) != 0) {
(void)markvoldirty(pmp, 0);
goto error_exit;
}
pmp->pm_fmod = 1;
}
mp->mnt_data = pmp;
mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
MNT_ILOCK(mp);
mp->mnt_flag |= MNT_LOCAL;
MNT_IUNLOCK(mp);
if (pmp->pm_flags & MSDOSFS_LARGEFS)
msdosfs_fileno_init(mp);
return 0;
error_exit:
if (bp)
brelse(bp);
if (cp != NULL) {
DROP_GIANT();
g_topology_lock();
g_vfs_close(cp);
g_topology_unlock();
PICKUP_GIANT();
}
if (pmp) {
lockdestroy(&pmp->pm_fatlock);
if (pmp->pm_inusemap)
free(pmp->pm_inusemap, M_MSDOSFSFAT);
free(pmp, M_MSDOSFSMNT);
mp->mnt_data = NULL;
}
dev_rel(dev);
return (error);
}
/*
* Unmount the filesystem described by mp.
*/
static int
msdosfs_unmount(struct mount *mp, int mntflags)
{
struct msdosfsmount *pmp;
int error, flags;
flags = 0;
if (mntflags & MNT_FORCE)
flags |= FORCECLOSE;
error = vflush(mp, 0, flags, curthread);
if (error && error != ENXIO)
return error;
pmp = VFSTOMSDOSFS(mp);
if ((pmp->pm_flags & MSDOSFSMNT_RONLY) == 0) {
error = markvoldirty(pmp, 0);
if (error && error != ENXIO) {
(void)markvoldirty(pmp, 1);
return (error);
}
}
if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
if (pmp->pm_w2u)
msdosfs_iconv->close(pmp->pm_w2u);
if (pmp->pm_u2w)
msdosfs_iconv->close(pmp->pm_u2w);
if (pmp->pm_d2u)
msdosfs_iconv->close(pmp->pm_d2u);
if (pmp->pm_u2d)
msdosfs_iconv->close(pmp->pm_u2d);
}
#ifdef MSDOSFS_DEBUG
{
struct vnode *vp = pmp->pm_devvp;
struct bufobj *bo;
bo = &vp->v_bufobj;
BO_LOCK(bo);
VI_LOCK(vp);
vn_printf(vp,
"msdosfs_umount(): just before calling VOP_CLOSE()\n");
printf("freef %p, freeb %p, mount %p\n",
TAILQ_NEXT(vp, v_actfreelist), vp->v_actfreelist.tqe_prev,
vp->v_mount);
printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
TAILQ_FIRST(&vp->v_bufobj.bo_clean.bv_hd),
TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd),
vp->v_bufobj.bo_numoutput, vp->v_type);
VI_UNLOCK(vp);
BO_UNLOCK(bo);
}
#endif
DROP_GIANT();
if (pmp->pm_devvp->v_type == VCHR && pmp->pm_devvp->v_rdev != NULL)
pmp->pm_devvp->v_rdev->si_mountpt = NULL;
g_topology_lock();
g_vfs_close(pmp->pm_cp);
g_topology_unlock();
PICKUP_GIANT();
vrele(pmp->pm_devvp);
dev_rel(pmp->pm_dev);
free(pmp->pm_inusemap, M_MSDOSFSFAT);
if (pmp->pm_flags & MSDOSFS_LARGEFS)
msdosfs_fileno_free(mp);
lockdestroy(&pmp->pm_fatlock);
free(pmp, M_MSDOSFSMNT);
mp->mnt_data = NULL;
MNT_ILOCK(mp);
mp->mnt_flag &= ~MNT_LOCAL;
MNT_IUNLOCK(mp);
return (error);
}
static int
msdosfs_root(struct mount *mp, int flags, struct vnode **vpp)
{
struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
struct denode *ndep;
int error;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
#endif
error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
if (error)
return (error);
*vpp = DETOV(ndep);
return (0);
}
static int
msdosfs_statfs(struct mount *mp, struct statfs *sbp)
{
struct msdosfsmount *pmp;
pmp = VFSTOMSDOSFS(mp);
sbp->f_bsize = pmp->pm_bpcluster;
sbp->f_iosize = pmp->pm_bpcluster;
sbp->f_blocks = pmp->pm_maxcluster + 1;
sbp->f_bfree = pmp->pm_freeclustercount;
sbp->f_bavail = pmp->pm_freeclustercount;
sbp->f_files = pmp->pm_RootDirEnts; /* XXX */
sbp->f_ffree = 0; /* what to put in here? */
return (0);
}
/*
* If we have an FSInfo block, update it.
*/
static int
msdosfs_fsiflush(struct msdosfsmount *pmp, int waitfor)
{
struct fsinfo *fp;
struct buf *bp;
int error;
MSDOSFS_LOCK_MP(pmp);
if (pmp->pm_fsinfo == 0 || (pmp->pm_flags & MSDOSFS_FSIMOD) == 0) {
error = 0;
goto unlock;
}
error = bread(pmp->pm_devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec,
NOCRED, &bp);
if (error != 0) {
brelse(bp);
goto unlock;
}
fp = (struct fsinfo *)bp->b_data;
putulong(fp->fsinfree, pmp->pm_freeclustercount);
putulong(fp->fsinxtfree, pmp->pm_nxtfree);
pmp->pm_flags &= ~MSDOSFS_FSIMOD;
if (waitfor == MNT_WAIT)
error = bwrite(bp);
else
bawrite(bp);
unlock:
MSDOSFS_UNLOCK_MP(pmp);
return (error);
}
static int
msdosfs_sync(struct mount *mp, int waitfor)
{
struct vnode *vp, *nvp;
struct thread *td;
struct denode *dep;
struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
int error, allerror = 0;
td = curthread;
/*
* 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.
*/
loop:
MNT_VNODE_FOREACH_ALL(vp, mp, nvp) {
if (vp->v_type == VNON) {
VI_UNLOCK(vp);
continue;
}
dep = VTODE(vp);
if ((dep->de_flag &
(DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
(vp->v_bufobj.bo_dirty.bv_cnt == 0 ||
waitfor == MNT_LAZY)) {
VI_UNLOCK(vp);
continue;
}
error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
if (error) {
if (error == ENOENT)
goto loop;
continue;
}
error = VOP_FSYNC(vp, waitfor, td);
if (error)
allerror = error;
VOP_UNLOCK(vp, 0);
vrele(vp);
}
/*
* Flush filesystem control info.
*/
if (waitfor != MNT_LAZY) {
vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_FSYNC(pmp->pm_devvp, waitfor, td);
if (error)
allerror = error;
VOP_UNLOCK(pmp->pm_devvp, 0);
}
error = msdosfs_fsiflush(pmp, waitfor);
if (error != 0)
allerror = error;
return (allerror);
}
static int
msdosfs_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp)
{
struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
struct defid *defhp = (struct defid *) fhp;
struct denode *dep;
int error;
error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
if (error) {
*vpp = NULLVP;
return (error);
}
*vpp = DETOV(dep);
vnode_create_vobject(*vpp, dep->de_FileSize, curthread);
return (0);
}
static struct vfsops msdosfs_vfsops = {
.vfs_fhtovp = msdosfs_fhtovp,
.vfs_mount = msdosfs_mount,
.vfs_cmount = msdosfs_cmount,
.vfs_root = msdosfs_root,
.vfs_statfs = msdosfs_statfs,
.vfs_sync = msdosfs_sync,
.vfs_unmount = msdosfs_unmount,
};
VFS_SET(msdosfs_vfsops, msdosfs, 0);
MODULE_VERSION(msdosfs, 1);
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