NetBSD/sys/msdosfs/msdosfs_vfsops.c

639 lines
17 KiB
C

/*
* 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
*
* $Id: msdosfs_vfsops.c,v 1.8 1994/02/07 23:14:23 cgd Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <miscfs/specfs/specdev.h> /* XXX */ /* defines v_rdev */
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/file.h>
#include <sys/malloc.h>
#include <msdosfs/bpb.h>
#include <msdosfs/bootsect.h>
#include <msdosfs/direntry.h>
#include <msdosfs/denode.h>
#include <msdosfs/msdosfsmount.h>
#include <msdosfs/fat.h>
int msdosfsdoforce = 0; /* 1 = force unmount */
/*
* 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(mp, path, data, ndp, p)
struct mount *mp;
char *path;
caddr_t data;
struct nameidata *ndp;
struct proc *p;
{
struct vnode *devvp; /* vnode for blk device to mount */
struct msdosfs_args args; /* will hold data from mount request */
struct msdosfsmount *pmp; /* msdosfs specific mount control block */
int error;
u_int size;
/*
* Copy in the args for the mount request.
*/
if (error = copyin(data, (caddr_t) & args, sizeof(struct msdosfs_args)))
return error;
#ifndef __NetBSD__
/*
* Check to see if they want it to be an exportable filesystem via
* nfs. And, if they do, should it be read only, and what uid is
* root to be mapped to.
*
* This is done in a completely different (and fs-indepdent) way
* in NetBSD.
*/
if ((args.exflags & MNT_EXPORTED) || (mp->mnt_flag & MNT_EXPORTED)) {
if (args.exflags & MNT_EXPORTED)
mp->mnt_flag |= MNT_EXPORTED;
else
mp->mnt_flag &= ~MNT_EXPORTED;
if (args.exflags & MNT_EXRDONLY)
mp->mnt_flag |= MNT_EXRDONLY;
else
mp->mnt_flag &= ~MNT_EXRDONLY;
mp->mnt_exroot = args.exroot;
}
#endif /* __NetBSD__ */
/*
* If they just want to update then be sure we can do what is
* asked. Can't change a filesystem from read/write to read only.
* Why? And if they've supplied a new device file name then we
* continue, otherwise return.
*/
if (mp->mnt_flag & MNT_UPDATE) {
pmp = (struct msdosfsmount *) mp->mnt_data;
if (pmp->pm_ronly && (mp->mnt_flag & MNT_RDONLY) == 0)
pmp->pm_ronly = 0;
if (args.fspec == 0)
return 0;
}
/*
* Now, lookup the name of the block device this mount or name
* update request is to apply to.
*/
ndp->ni_nameiop = LOOKUP | FOLLOW;
ndp->ni_segflg = UIO_USERSPACE;
ndp->ni_dirp = args.fspec;
if (error = namei(ndp, p))
return error;
/*
* Be sure they've given us a block device to treat as a
* filesystem. And, that its major number is within the bdevsw
* table.
*/
devvp = ndp->ni_vp;
if (devvp->v_type != VBLK) {
vrele(devvp); /* namei() acquires this? */
return ENOTBLK;
}
if (major(devvp->v_rdev) >= nblkdev) {
vrele(devvp);
return ENXIO;
}
/*
* If this is an update, then make sure the vnode for the block
* special device is the same as the one our filesystem is in.
*/
if (mp->mnt_flag & MNT_UPDATE) {
if (devvp != pmp->pm_devvp)
error = EINVAL;
else
vrele(devvp);
}
else {
/*
* Well, it's not an update, it's a real mount request.
* Time to get dirty.
*/
error = mountmsdosfs(devvp, mp, p);
}
if (error) {
vrele(devvp);
return error;
}
/*
* Copy in the name of the directory the filesystem is to be
* mounted on. Then copy in the name of the block special file
* representing the filesystem being mounted. And we clear the
* remainder of the character strings to be tidy. Then, we try to
* fill in the filesystem stats structure as best we can with
* whatever applies from a dos file system.
*/
pmp = (struct msdosfsmount *) mp->mnt_data;
copyinstr(path, (caddr_t) mp->mnt_stat.f_mntonname,
sizeof(mp->mnt_stat.f_mntonname) - 1, &size);
bzero(mp->mnt_stat.f_mntonname + size,
sizeof(mp->mnt_stat.f_mntonname) - size);
copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
bzero(mp->mnt_stat.f_mntfromname + size,
MNAMELEN - size);
(void) msdosfs_statfs(mp, &mp->mnt_stat, p);
#if defined(MSDOSFSDEBUG)
printf("msdosfs_mount(): mp %x, pmp %x, inusemap %x\n", mp, pmp, pmp->pm_inusemap);
#endif /* defined(MSDOSFSDEBUG) */
return 0;
}
int
mountmsdosfs(devvp, mp, p)
struct vnode *devvp;
struct mount *mp;
struct proc *p;
{
int i;
int bpc;
int bit;
int error = 0;
int needclose;
int ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
dev_t dev = devvp->v_rdev;
union bootsector *bsp;
struct msdosfsmount *pmp = NULL;
struct buf *bp0 = NULL;
struct byte_bpb33 *b33;
struct byte_bpb50 *b50;
/*
* Multiple mounts of the same block special file aren't allowed.
* Make sure no one else has the special file open. And flush any
* old buffers from this filesystem. Presumably this prevents us
* from running into buffers that are the wrong blocksize. NOTE:
* mountedon() is a part of the ufs filesystem. If the ufs
* filesystem is not gen'ed into the system we will get an
* unresolved reference.
*/
if (error = mountedon(devvp)) {
return error;
}
if (vcount(devvp) > 1)
return EBUSY;
vinvalbuf(devvp, 1);
/*
* Now open the block special file.
*/
if (error = VOP_OPEN(devvp, ronly ? FREAD : FREAD | FWRITE, NOCRED, p))
return error;
needclose = 1;
#if defined(HDSUPPORT)
/*
* Put this in when we support reading dos filesystems from
* partitioned harddisks.
*/
if (VOP_IOCTL(devvp, DIOCGPART, &msdosfspart, FREAD, NOCRED, p) == 0) {
}
#endif /* defined(HDSUPPORT) */
/*
* Read the boot sector of the filesystem, and then check the boot
* signature. If not a dos boot sector then error out. We could
* also add some checking on the bsOemName field. So far I've seen
* the following values: "IBM 3.3" "MSDOS3.3" "MSDOS5.0"
*/
if (error = bread(devvp, 0, 512, NOCRED, &bp0))
goto error_exit;
bp0->b_flags |= B_AGE;
bsp = (union bootsector *) bp0->b_un.b_addr;
b33 = (struct byte_bpb33 *) bsp->bs33.bsBPB;
b50 = (struct byte_bpb50 *) bsp->bs50.bsBPB;
#ifdef MSDOSFS_CHECKSIG
if (bsp->bs50.bsBootSectSig != BOOTSIG) {
error = EINVAL;
goto error_exit;
}
#endif
if ( bsp->bs50.bsJump[0] != 0xe9 &&
(bsp->bs50.bsJump[0] != 0xeb || bsp->bs50.bsJump[2] != 0x90)) {
error = EINVAL;
goto error_exit;
}
pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
pmp->pm_inusemap = NULL;
pmp->pm_fmod = 0;
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.
*/
pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
pmp->pm_SectPerClust = b50->bpbSecPerClust;
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_Media = b50->bpbMedia;
pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
pmp->pm_Heads = getushort(b50->bpbHeads);
/* XXX - We should probably check more values here */
if (!pmp->pm_BytesPerSec || !pmp->pm_SectPerClust ||
!pmp->pm_Heads || pmp->pm_Heads > 255 ||
!pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
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;
}
pmp->pm_fatblk = pmp->pm_ResSectors;
pmp->pm_rootdirblk = pmp->pm_fatblk +
(pmp->pm_FATs * pmp->pm_FATsecs);
pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry))
/
pmp->pm_BytesPerSec;/* in sectors */
pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
pmp->pm_SectPerClust;
pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
if (FAT12(pmp))
/*
* This will usually be a floppy disk. This size makes sure
* that one fat entry will not be split across multiple
* blocks.
*/
pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
else
/*
* This will usually be a hard disk. Reading or writing one
* block should be quite fast.
*/
pmp->pm_fatblocksize = MAXBSIZE;
pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
if ((pmp->pm_rootdirsize % pmp->pm_SectPerClust) != 0)
printf("mountmsdosfs(): root directory is not a multiple of the clustersize in length\n");
/*
* Compute mask and shift value for isolating cluster relative byte
* offsets and cluster numbers from a file offset.
*/
bpc = pmp->pm_SectPerClust * pmp->pm_BytesPerSec;
pmp->pm_bpcluster = bpc;
pmp->pm_depclust = bpc / sizeof(struct direntry);
pmp->pm_crbomask = bpc - 1;
if (bpc == 0) {
error = EINVAL;
goto error_exit;
}
bit = 1;
for (i = 0; i < 32; i++) {
if (bit & bpc) {
if (bit ^ bpc) {
error = EINVAL;
goto error_exit;
}
pmp->pm_cnshift = i;
break;
}
bit <<= 1;
}
pmp->pm_brbomask = 0x01ff; /* 512 byte blocks only (so far) */
pmp->pm_bnshift = 9; /* shift right 9 bits to get bn */
/*
* Release the bootsector buffer.
*/
brelse(bp0);
bp0 = NULL;
/*
* Allocate memory for the bitmap of allocated clusters, and then
* fill it in.
*/
pmp->pm_inusemap = malloc((pmp->pm_maxcluster >> 3) + 1,
M_MSDOSFSFAT, M_WAITOK);
/*
* fillinusemap() needs pm_devvp.
*/
pmp->pm_dev = dev;
pmp->pm_devvp = devvp;
/*
* Have the inuse map filled in.
*/
error = fillinusemap(pmp);
if (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.
*/
pmp->pm_waitonfat = mp->mnt_flag & MNT_SYNCHRONOUS;
/*
* Finish up.
*/
pmp->pm_ronly = ronly;
if (ronly == 0)
pmp->pm_fmod = 1;
mp->mnt_data = (qaddr_t) pmp;
mp->mnt_stat.f_fsid.val[0] = (long) dev;
mp->mnt_stat.f_fsid.val[1] = MOUNT_MSDOS;
mp->mnt_flag |= MNT_LOCAL;
#if defined(QUOTA)
/*
* 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.
*/
#endif /* defined(QUOTA) */
devvp->v_specflags |= SI_MOUNTEDON;
return 0;
error_exit:;
if (bp0)
brelse(bp0);
if (needclose)
(void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE,
NOCRED, p);
if (pmp) {
if (pmp->pm_inusemap)
free((caddr_t) pmp->pm_inusemap, M_MSDOSFSFAT);
free((caddr_t) pmp, M_MSDOSFSMNT);
mp->mnt_data = (qaddr_t) 0;
}
return error;
}
int
msdosfs_start(mp, flags, p)
struct mount *mp;
int flags;
struct proc *p;
{
return 0;
}
/*
* Unmount the filesystem described by mp.
*/
int
msdosfs_unmount(mp, mntflags, p)
struct mount *mp;
int mntflags;
struct proc *p;
{
int flags = 0;
int error;
struct msdosfsmount *pmp = (struct msdosfsmount *) mp->mnt_data;
struct vnode *vp = pmp->pm_devvp;
if (mntflags & MNT_FORCE) {
if (!msdosfsdoforce)
return EINVAL;
flags |= FORCECLOSE;
}
mntflushbuf(mp, 0);
if (mntinvalbuf(mp))
return EBUSY;
#if defined(QUOTA)
#endif /* defined(QUOTA) */
if (error = vflush(mp, NULLVP, flags))
return error;
pmp->pm_devvp->v_specflags &= ~SI_MOUNTEDON;
#if defined(MSDOSFSDEBUG)
printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
printf("flag %08x, usecount %d, writecount %d, holdcnt %d\n",
vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
printf("lastr %d, id %d, mount %08x, op %08x\n",
vp->v_lastr, vp->v_id, vp->v_mount, vp->v_op);
printf("freef %08x, freeb %08x, mountf %08x, mountb %08x\n",
vp->v_freef, vp->v_freeb, vp->v_mountf, vp->v_mountb);
printf("cleanblkhd %08x, dirtyblkhd %08x, numoutput %d, type %d\n",
vp->v_cleanblkhd, vp->v_dirtyblkhd, vp->v_numoutput, vp->v_type);
printf("union %08x, tag %d, data[0] %08x, data[1] %08x\n",
vp->v_socket, vp->v_tag, vp->v_data[0], vp->v_data[1]);
#endif /* defined(MSDOSFSDEBUG) */
error = VOP_CLOSE(pmp->pm_devvp, pmp->pm_ronly ? FREAD : FREAD | FWRITE,
NOCRED, p);
vrele(pmp->pm_devvp);
free((caddr_t) pmp->pm_inusemap, M_MSDOSFSFAT);
free((caddr_t) pmp, M_MSDOSFSMNT);
mp->mnt_data = (qaddr_t) 0;
mp->mnt_flag &= ~MNT_LOCAL;
return error;
}
int
msdosfs_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct denode *ndep;
struct msdosfsmount *pmp = (struct msdosfsmount *) (mp->mnt_data);
int error;
error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, NULL, &ndep);
#if defined(MSDOSFSDEBUG)
printf("msdosfs_root(); mp %08x, pmp %08x, ndep %08x, vp %08x\n",
mp, pmp, ndep, DETOV(ndep));
#endif /* defined(MSDOSFSDEBUG) */
if (error == 0)
*vpp = DETOV(ndep);
return error;
}
int
msdosfs_quotactl(mp, cmds, uid, arg, p)
struct mount *mp;
int cmds;
uid_t uid;
caddr_t arg;
struct proc *p;
{
#if defined(QUOTA)
#else
return EOPNOTSUPP;
#endif /* defined(QUOTA) */
}
int
msdosfs_statfs(mp, sbp, p)
struct mount *mp;
struct statfs *sbp;
struct proc *p;
{
struct msdosfsmount *pmp = (struct msdosfsmount *) mp->mnt_data;
/*
* Fill in the stat block.
*/
sbp->f_type = MOUNT_MSDOS;
sbp->f_fsize = pmp->pm_bpcluster;
sbp->f_bsize = pmp->pm_bpcluster;
sbp->f_blocks = pmp->pm_nmbrofclusters;
sbp->f_bfree = pmp->pm_freeclustercount;
sbp->f_bavail = pmp->pm_freeclustercount;
sbp->f_files = pmp->pm_RootDirEnts;
sbp->f_ffree = 0; /* what to put in here? */
/*
* Copy the mounted on and mounted from names into the passed in
* stat block, if it is not the one in the mount structure.
*/
if (sbp != &mp->mnt_stat) {
bcopy((caddr_t) mp->mnt_stat.f_mntonname,
(caddr_t) & sbp->f_mntonname[0], MNAMELEN);
bcopy((caddr_t) mp->mnt_stat.f_mntfromname,
(caddr_t) & sbp->f_mntfromname[0], MNAMELEN);
}
return 0;
}
int
msdosfs_sync(mp, waitfor)
struct mount *mp;
int waitfor;
{
struct vnode *vp;
struct denode *dep;
struct msdosfsmount *pmp;
int error;
int allerror = 0;
pmp = (struct msdosfsmount *) mp->mnt_data;
/*
* 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)
if (pmp->pm_ronly)
panic("msdosfs_sync: rofs mod");
else {
/* update fats here */
}
/*
* Go thru in memory denodes and write them out along with
* unwritten file blocks.
*/
loop:
for (vp = mp->mnt_mounth; vp; vp = vp->v_mountf) {
if (vp->v_mount != mp) /* not ours anymore */
goto loop;
if (VOP_ISLOCKED(vp)) /* file is busy */
continue;
dep = VTODE(vp);
if ((dep->de_flag & DEUPD) == 0 && vp->v_dirtyblkhd == NULL)
continue;
if (vget(vp)) /* not there anymore? */
goto loop;
if (vp->v_dirtyblkhd) /* flush dirty file blocks */
vflushbuf(vp, 0);
if ((dep->de_flag & DEUPD) &&
(error = deupdat(dep, &time, 0)))
allerror = error;
vput(vp); /* done with this one */
}
/*
* Flush filesystem control info.
*/
vflushbuf(pmp->pm_devvp, waitfor == MNT_WAIT ? B_SYNC : 0);
return allerror;
}
int
msdosfs_fhtovp(mp, fhp, vpp)
struct mount *mp;
struct fid *fhp;
struct vnode **vpp;
{
struct msdosfsmount *pmp = (struct msdosfsmount *) mp->mnt_data;
struct defid *defhp = (struct defid *) fhp;
struct denode *dep;
int error;
error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs,
NULL, &dep);
if (error)
return (error);
*vpp = DETOV(dep);
return (0);
}
int
msdosfs_vptofh(vp, fhp)
struct vnode *vp;
struct fid *fhp;
{
struct denode *dep = VTODE(vp);
struct defid *defhp = (struct defid *) fhp;
defhp->defid_len = sizeof(struct defid);
defhp->defid_dirclust = dep->de_dirclust;
defhp->defid_dirofs = dep->de_diroffset;
/* defhp->defid_gen = ip->i_gen; */
return (0);
}
struct vfsops msdosfs_vfsops = {
msdosfs_mount,
msdosfs_start,
msdosfs_unmount,
msdosfs_root,
msdosfs_quotactl,
msdosfs_statfs,
msdosfs_sync,
msdosfs_fhtovp,
msdosfs_vptofh,
msdosfs_init
};