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ca21a25f17
freebsd-skq/sys/msdosfs/msdosfs_vnops.c
phk ca21a25f17 This Implements the mumbled about "Jail" feature. 
This is a seriously beefed up chroot kind of thing.  The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.

For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact:  "real virtual servers".

Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.

Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.

It generally does what one would expect, but setting up a jail
still takes a little knowledge.

A few notes:

   I have no scripts for setting up a jail, don't ask me for them.

   The IP number should be an alias on one of the interfaces.

   mount a /proc in each jail, it will make ps more useable.

   /proc/<pid>/status tells the hostname of the prison for
   jailed processes.

   Quotas are only sensible if you have a mountpoint per prison.

   There are no privisions for stopping resource-hogging.

   Some "#ifdef INET" and similar may be missing (send patches!)

If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!

Tools, comments, patches & documentation most welcome.

Have fun...

Sponsored by:   http://www.rndassociates.com/
Run for almost a year by:       http://www.servetheweb.com/
1999-04-28 11:38:52 +00:00

1984 lines
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/* $Id: msdosfs_vnops.c,v 1.82 1999/04/27 11:16:51 phk Exp $ */
/* $NetBSD: msdosfs_vnops.c,v 1.68 1998/02/10 14:10:04 mrg 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/namei.h>
#include <sys/resourcevar.h> /* defines plimit structure in proc struct */
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <miscfs/specfs/specdev.h> /* XXX */ /* defines v_rdev */
#include <sys/malloc.h>
#include <sys/dirent.h>
#include <sys/signalvar.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_zone.h>
#include <vm/vnode_pager.h>
#include <msdosfs/bpb.h>
#include <msdosfs/direntry.h>
#include <msdosfs/denode.h>
#include <msdosfs/msdosfsmount.h>
#include <msdosfs/fat.h>
/*
* Prototypes for MSDOSFS vnode operations
*/
static int msdosfs_create __P((struct vop_create_args *));
static int msdosfs_mknod __P((struct vop_mknod_args *));
static int msdosfs_close __P((struct vop_close_args *));
static int msdosfs_access __P((struct vop_access_args *));
static int msdosfs_getattr __P((struct vop_getattr_args *));
static int msdosfs_setattr __P((struct vop_setattr_args *));
static int msdosfs_read __P((struct vop_read_args *));
static int msdosfs_write __P((struct vop_write_args *));
static int msdosfs_fsync __P((struct vop_fsync_args *));
static int msdosfs_remove __P((struct vop_remove_args *));
static int msdosfs_link __P((struct vop_link_args *));
static int msdosfs_rename __P((struct vop_rename_args *));
static int msdosfs_mkdir __P((struct vop_mkdir_args *));
static int msdosfs_rmdir __P((struct vop_rmdir_args *));
static int msdosfs_symlink __P((struct vop_symlink_args *));
static int msdosfs_readdir __P((struct vop_readdir_args *));
static int msdosfs_abortop __P((struct vop_abortop_args *));
static int msdosfs_bmap __P((struct vop_bmap_args *));
static int msdosfs_strategy __P((struct vop_strategy_args *));
static int msdosfs_print __P((struct vop_print_args *));
static int msdosfs_pathconf __P((struct vop_pathconf_args *ap));
static int msdosfs_getpages __P((struct vop_getpages_args *));
static int msdosfs_putpages __P((struct vop_putpages_args *));
/*
* Some general notes:
*
* In the ufs filesystem the inodes, superblocks, and indirect blocks are
* read/written using the vnode for the filesystem. Blocks that represent
* the contents of a file are read/written using the vnode for the file
* (including directories when they are read/written as files). This
* presents problems for the dos filesystem because data that should be in
* an inode (if dos had them) resides in the directory itself. Since we
* must update directory entries without the benefit of having the vnode
* for the directory we must use the vnode for the filesystem. This means
* that when a directory is actually read/written (via read, write, or
* readdir, or seek) we must use the vnode for the filesystem instead of
* the vnode for the directory as would happen in ufs. This is to insure we
* retreive the correct block from the buffer cache since the hash value is
* based upon the vnode address and the desired block number.
*/
/*
* Create a regular file. On entry the directory to contain the file being
* created is locked. We must release before we return. We must also free
* the pathname buffer pointed at by cnp->cn_pnbuf, always on error, or
* only if the SAVESTART bit in cn_flags is clear on success.
*/
static int
msdosfs_create(ap)
struct vop_create_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */ *ap;
{
struct componentname *cnp = ap->a_cnp;
struct denode ndirent;
struct denode *dep;
struct denode *pdep = VTODE(ap->a_dvp);
struct timespec ts;
int error;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_create(cnp %p, vap %p\n", cnp, ap->a_vap);
#endif
/*
* If this is the root directory and there is no space left we
* can't do anything. This is because the root directory can not
* change size.
*/
if (pdep->de_StartCluster == MSDOSFSROOT
&& pdep->de_fndoffset >= pdep->de_FileSize) {
error = ENOSPC;
goto bad;
}
/*
* Create a directory entry for the file, then call createde() to
* have it installed. NOTE: DOS files are always executable. We
* use the absence of the owner write bit to make the file
* readonly.
*/
#ifdef DIAGNOSTIC
if ((cnp->cn_flags & HASBUF) == 0)
panic("msdosfs_create: no name");
#endif
bzero(&ndirent, sizeof(ndirent));
error = uniqdosname(pdep, cnp, ndirent.de_Name);
if (error)
goto bad;
ndirent.de_Attributes = (ap->a_vap->va_mode & VWRITE) ?
ATTR_ARCHIVE : ATTR_ARCHIVE | ATTR_READONLY;
ndirent.de_LowerCase = 0;
ndirent.de_StartCluster = 0;
ndirent.de_FileSize = 0;
ndirent.de_dev = pdep->de_dev;
ndirent.de_devvp = pdep->de_devvp;
ndirent.de_pmp = pdep->de_pmp;
ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
getnanotime(&ts);
DETIMES(&ndirent, &ts, &ts, &ts);
error = createde(&ndirent, pdep, &dep, cnp);
if (error)
goto bad;
if ((cnp->cn_flags & SAVESTART) == 0)
zfree(namei_zone, cnp->cn_pnbuf);
*ap->a_vpp = DETOV(dep);
return (0);
bad:
zfree(namei_zone, cnp->cn_pnbuf);
return (error);
}
static int
msdosfs_mknod(ap)
struct vop_mknod_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */ *ap;
{
switch (ap->a_vap->va_type) {
case VDIR:
return (msdosfs_mkdir((struct vop_mkdir_args *)ap));
break;
case VREG:
return (msdosfs_create((struct vop_create_args *)ap));
break;
default:
zfree(namei_zone, ap->a_cnp->cn_pnbuf);
return (EINVAL);
}
/* NOTREACHED */
}
static int
msdosfs_close(ap)
struct vop_close_args /* {
struct vnode *a_vp;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(vp);
struct timespec ts;
simple_lock(&vp->v_interlock);
if (vp->v_usecount > 1) {
getnanotime(&ts);
DETIMES(dep, &ts, &ts, &ts);
}
simple_unlock(&vp->v_interlock);
return 0;
}
static int
msdosfs_access(ap)
struct vop_access_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(ap->a_vp);
struct msdosfsmount *pmp = dep->de_pmp;
struct ucred *cred = ap->a_cred;
mode_t mask, file_mode, mode = ap->a_mode;
register gid_t *gp;
int i;
file_mode = (S_IXUSR|S_IXGRP|S_IXOTH) | (S_IRUSR|S_IRGRP|S_IROTH) |
((dep->de_Attributes & ATTR_READONLY) ? 0 : (S_IWUSR|S_IWGRP|S_IWOTH));
file_mode &= pmp->pm_mask;
/*
* Disallow write attempts on read-only file systems;
* unless the file is a socket, fifo, or a block or
* character device resident on the file system.
*/
if (mode & VWRITE) {
switch (vp->v_type) {
case VDIR:
case VLNK:
case VREG:
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
break;
default:
break;
}
}
/* User id 0 always gets access. */
if (cred->cr_uid == 0)
return 0;
mask = 0;
/* Otherwise, check the owner. */
if (cred->cr_uid == pmp->pm_uid) {
if (mode & VEXEC)
mask |= S_IXUSR;
if (mode & VREAD)
mask |= S_IRUSR;
if (mode & VWRITE)
mask |= S_IWUSR;
return (file_mode & mask) == mask ? 0 : EACCES;
}
/* Otherwise, check the groups. */
for (i = 0, gp = cred->cr_groups; i < cred->cr_ngroups; i++, gp++)
if (pmp->pm_gid == *gp) {
if (mode & VEXEC)
mask |= S_IXGRP;
if (mode & VREAD)
mask |= S_IRGRP;
if (mode & VWRITE)
mask |= S_IWGRP;
return (file_mode & mask) == mask ? 0 : EACCES;
}
/* Otherwise, check everyone else. */
if (mode & VEXEC)
mask |= S_IXOTH;
if (mode & VREAD)
mask |= S_IROTH;
if (mode & VWRITE)
mask |= S_IWOTH;
return (file_mode & mask) == mask ? 0 : EACCES;
}
static int
msdosfs_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct denode *dep = VTODE(ap->a_vp);
struct msdosfsmount *pmp = dep->de_pmp;
struct vattr *vap = ap->a_vap;
mode_t mode;
struct timespec ts;
u_long dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
u_long fileid;
getnanotime(&ts);
DETIMES(dep, &ts, &ts, &ts);
vap->va_fsid = dep->de_dev;
/*
* The following computation of the fileid must be the same as that
* used in msdosfs_readdir() to compute d_fileno. If not, pwd
* doesn't work.
*/
if (dep->de_Attributes & ATTR_DIRECTORY) {
fileid = cntobn(pmp, dep->de_StartCluster) * dirsperblk;
if (dep->de_StartCluster == MSDOSFSROOT)
fileid = 1;
} else {
fileid = cntobn(pmp, dep->de_dirclust) * dirsperblk;
if (dep->de_dirclust == MSDOSFSROOT)
fileid = roottobn(pmp, 0) * dirsperblk;
fileid += dep->de_diroffset / sizeof(struct direntry);
}
vap->va_fileid = fileid;
if ((dep->de_Attributes & ATTR_READONLY) == 0)
mode = S_IRWXU|S_IRWXG|S_IRWXO;
else
mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
vap->va_mode = mode & pmp->pm_mask;
vap->va_uid = pmp->pm_uid;
vap->va_gid = pmp->pm_gid;
vap->va_nlink = 1;
vap->va_rdev = 0;
vap->va_size = dep->de_FileSize;
dos2unixtime(dep->de_MDate, dep->de_MTime, 0, &vap->va_mtime);
if (pmp->pm_flags & MSDOSFSMNT_LONGNAME) {
dos2unixtime(dep->de_ADate, 0, 0, &vap->va_atime);
dos2unixtime(dep->de_CDate, dep->de_CTime, dep->de_CHun, &vap->va_ctime);
} else {
vap->va_atime = vap->va_mtime;
vap->va_ctime = vap->va_mtime;
}
vap->va_flags = 0;
if ((dep->de_Attributes & ATTR_ARCHIVE) == 0)
vap->va_flags |= SF_ARCHIVED;
vap->va_gen = 0;
vap->va_blocksize = pmp->pm_bpcluster;
vap->va_bytes =
(dep->de_FileSize + pmp->pm_crbomask) & ~pmp->pm_crbomask;
vap->va_type = ap->a_vp->v_type;
vap->va_filerev = dep->de_modrev;
return (0);
}
static int
msdosfs_setattr(ap)
struct vop_setattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(ap->a_vp);
struct msdosfsmount *pmp = dep->de_pmp;
struct vattr *vap = ap->a_vap;
struct ucred *cred = ap->a_cred;
int error = 0;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_setattr(): vp %p, vap %p, cred %p, p %p\n",
ap->a_vp, vap, cred, ap->a_p);
#endif
/*
* Check for unsettable attributes.
*/
if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
(vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
(vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
(vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
#ifdef MSDOSFS_DEBUG
printf("msdosfs_setattr(): returning EINVAL\n");
printf(" va_type %d, va_nlink %x, va_fsid %lx, va_fileid %lx\n",
vap->va_type, vap->va_nlink, vap->va_fsid, vap->va_fileid);
printf(" va_blocksize %lx, va_rdev %x, va_bytes %qx, va_gen %lx\n",
vap->va_blocksize, vap->va_rdev, vap->va_bytes, vap->va_gen);
printf(" va_uid %x, va_gid %x\n",
vap->va_uid, vap->va_gid);
#endif
return (EINVAL);
}
if (vap->va_flags != VNOVAL) {
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
if (cred->cr_uid != pmp->pm_uid &&
(error = suser_xxx(cred, ap->a_p, PRISON_ROOT)))
return (error);
/*
* We are very inconsistent about handling unsupported
* attributes. We ignored the access time and the
* read and execute bits. We were strict for the other
* attributes.
*
* Here we are strict, stricter than ufs in not allowing
* users to attempt to set SF_SETTABLE bits or anyone to
* set unsupported bits. However, we ignore attempts to
* set ATTR_ARCHIVE for directories `cp -pr' from a more
* sensible file system attempts it a lot.
*/
if (cred->cr_uid != 0) {
if (vap->va_flags & SF_SETTABLE)
return EPERM;
}
if (vap->va_flags & ~SF_ARCHIVED)
return EOPNOTSUPP;
if (vap->va_flags & SF_ARCHIVED)
dep->de_Attributes &= ~ATTR_ARCHIVE;
else if (!(dep->de_Attributes & ATTR_DIRECTORY))
dep->de_Attributes |= ATTR_ARCHIVE;
dep->de_flag |= DE_MODIFIED;
}
if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
uid_t uid;
gid_t gid;
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
uid = vap->va_uid;
if (uid == (uid_t)VNOVAL)
uid = pmp->pm_uid;
gid = vap->va_gid;
if (gid == (gid_t)VNOVAL)
gid = pmp->pm_gid;
if ((cred->cr_uid != pmp->pm_uid || uid != pmp->pm_uid ||
(gid != pmp->pm_gid && !groupmember(gid, cred))) &&
(error = suser_xxx(cred, ap->a_p, PRISON_ROOT)))
return error;
if (uid != pmp->pm_uid || gid != pmp->pm_gid)
return EINVAL;
}
if (vap->va_size != VNOVAL) {
/*
* Disallow write attempts on read-only file systems;
* unless the file is a socket, fifo, or a block or
* character device resident on the file system.
*/
switch (vp->v_type) {
case VDIR:
return (EISDIR);
/* NOT REACHED */
case VLNK:
case VREG:
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
break;
default:
break;
}
error = detrunc(dep, vap->va_size, 0, cred, ap->a_p);
if (error)
return error;
}
if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
if (cred->cr_uid != pmp->pm_uid &&
(error = suser_xxx(cred, ap->a_p, PRISON_ROOT)) &&
((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
(error = VOP_ACCESS(ap->a_vp, VWRITE, cred, ap->a_p))))
return (error);
if (vp->v_type != VDIR) {
if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) == 0 &&
vap->va_atime.tv_sec != VNOVAL)
unix2dostime(&vap->va_atime, &dep->de_ADate, NULL, NULL);
if (vap->va_mtime.tv_sec != VNOVAL)
unix2dostime(&vap->va_mtime, &dep->de_MDate, &dep->de_MTime, NULL);
dep->de_Attributes |= ATTR_ARCHIVE;
dep->de_flag |= DE_MODIFIED;
}
}
/*
* DOS files only have the ability to have their writability
* attribute set, so we use the owner write bit to set the readonly
* attribute.
*/
if (vap->va_mode != (mode_t)VNOVAL) {
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
if (cred->cr_uid != pmp->pm_uid &&
(error = suser_xxx(cred, ap->a_p, PRISON_ROOT)))
return (error);
if (vp->v_type != VDIR) {
/* We ignore the read and execute bits. */
if (vap->va_mode & VWRITE)
dep->de_Attributes &= ~ATTR_READONLY;
else
dep->de_Attributes |= ATTR_READONLY;
dep->de_flag |= DE_MODIFIED;
}
}
return (deupdat(dep, 1));
}
static int
msdosfs_read(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
int error = 0;
int diff;
int blsize;
int isadir;
long n;
long on;
daddr_t lbn;
daddr_t rablock;
int rasize;
struct buf *bp;
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(vp);
struct msdosfsmount *pmp = dep->de_pmp;
struct uio *uio = ap->a_uio;
/*
* If they didn't ask for any data, then we are done.
*/
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
isadir = dep->de_Attributes & ATTR_DIRECTORY;
do {
lbn = de_cluster(pmp, uio->uio_offset);
on = uio->uio_offset & pmp->pm_crbomask;
n = min((u_long) (pmp->pm_bpcluster - on), uio->uio_resid);
diff = dep->de_FileSize - uio->uio_offset;
if (diff <= 0)
return (0);
if (diff < n)
n = diff;
/* convert cluster # to block # if a directory */
if (isadir) {
error = pcbmap(dep, lbn, &lbn, 0, &blsize);
if (error)
return (error);
}
/*
* If we are operating on a directory file then be sure to
* do i/o with the vnode for the filesystem instead of the
* vnode for the directory.
*/
if (isadir) {
error = bread(pmp->pm_devvp, lbn, blsize, NOCRED, &bp);
} else {
rablock = lbn + 1;
if (vp->v_lastr + 1 == lbn &&
de_cn2off(pmp, rablock) < dep->de_FileSize) {
rasize = pmp->pm_bpcluster;
error = breadn(vp, lbn, pmp->pm_bpcluster,
&rablock, &rasize, 1, NOCRED, &bp);
} else
error = bread(vp, lbn, pmp->pm_bpcluster,
NOCRED, &bp);
vp->v_lastr = lbn;
}
n = min(n, pmp->pm_bpcluster - bp->b_resid);
if (error) {
brelse(bp);
return (error);
}
error = uiomove(bp->b_data + on, (int) n, uio);
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
if (!isadir && !(vp->v_mount->mnt_flag & MNT_NOATIME))
dep->de_flag |= DE_ACCESS;
return (error);
}
/*
* Write data to a file or directory.
*/
static int
msdosfs_write(ap)
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
int n;
int croffset;
int resid;
u_long osize;
int error = 0;
u_long count;
daddr_t bn, lastcn;
struct buf *bp;
int ioflag = ap->a_ioflag;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct vnode *vp = ap->a_vp;
struct vnode *thisvp;
struct denode *dep = VTODE(vp);
struct msdosfsmount *pmp = dep->de_pmp;
struct ucred *cred = ap->a_cred;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_write(vp %p, uio %p, ioflag %x, cred %p\n",
vp, uio, ioflag, cred);
printf("msdosfs_write(): diroff %lu, dirclust %lu, startcluster %lu\n",
dep->de_diroffset, dep->de_dirclust, dep->de_StartCluster);
#endif
switch (vp->v_type) {
case VREG:
if (ioflag & IO_APPEND)
uio->uio_offset = dep->de_FileSize;
thisvp = vp;
break;
case VDIR:
return EISDIR;
default:
panic("msdosfs_write(): bad file type");
}
if (uio->uio_offset < 0)
return (EINVAL);
if (uio->uio_resid == 0)
return (0);
/*
* If they've exceeded their filesize limit, tell them about it.
*/
if (p &&
((uio->uio_offset + uio->uio_resid) >
p->p_rlimit[RLIMIT_FSIZE].rlim_cur)) {
psignal(p, SIGXFSZ);
return (EFBIG);
}
/*
* If the offset we are starting the write at is beyond the end of
* the file, then they've done a seek. Unix filesystems allow
* files with holes in them, DOS doesn't so we must fill the hole
* with zeroed blocks.
*/
if (uio->uio_offset > dep->de_FileSize) {
error = deextend(dep, uio->uio_offset, cred);
if (error)
return (error);
}
/*
* Remember some values in case the write fails.
*/
resid = uio->uio_resid;
osize = dep->de_FileSize;
/*
* If we write beyond the end of the file, extend it to its ultimate
* size ahead of the time to hopefully get a contiguous area.
*/
if (uio->uio_offset + resid > osize) {
count = de_clcount(pmp, uio->uio_offset + resid) -
de_clcount(pmp, osize);
error = extendfile(dep, count, NULL, NULL, 0);
if (error && (error != ENOSPC || (ioflag & IO_UNIT)))
goto errexit;
lastcn = dep->de_fc[FC_LASTFC].fc_frcn;
} else
lastcn = de_clcount(pmp, osize) - 1;
do {
if (de_cluster(pmp, uio->uio_offset) > lastcn) {
error = ENOSPC;
break;
}
croffset = uio->uio_offset & pmp->pm_crbomask;
n = min(uio->uio_resid, pmp->pm_bpcluster - croffset);
if (uio->uio_offset + n > dep->de_FileSize) {
dep->de_FileSize = uio->uio_offset + n;
/* The object size needs to be set before buffer is allocated */
vnode_pager_setsize(vp, dep->de_FileSize);
}
bn = de_cluster(pmp, uio->uio_offset);
if ((uio->uio_offset & pmp->pm_crbomask) == 0
&& (de_cluster(pmp, uio->uio_offset + uio->uio_resid)
> de_cluster(pmp, uio->uio_offset)
|| uio->uio_offset + uio->uio_resid >= dep->de_FileSize)) {
/*
* If either the whole cluster gets written,
* or we write the cluster from its start beyond EOF,
* then no need to read data from disk.
*/
bp = getblk(thisvp, bn, pmp->pm_bpcluster, 0, 0);
clrbuf(bp);
/*
* Do the bmap now, since pcbmap needs buffers
* for the fat table. (see msdosfs_strategy)
*/
if (bp->b_blkno == bp->b_lblkno) {
error = pcbmap(dep, bp->b_lblkno, &bp->b_blkno,
0, 0);
if (error)
bp->b_blkno = -1;
}
if (bp->b_blkno == -1) {
brelse(bp);
if (!error)
error = EIO; /* XXX */
break;
}
} else {
/*
* The block we need to write into exists, so read it in.
*/
error = bread(thisvp, bn, pmp->pm_bpcluster, cred, &bp);
if (error) {
brelse(bp);
break;
}
}
/*
* Should these vnode_pager_* functions be done on dir
* files?
*/
/*
* Copy the data from user space into the buf header.
*/
error = uiomove(bp->b_data + croffset, n, uio);
/*
* If they want this synchronous then write it and wait for
* it. Otherwise, if on a cluster boundary write it
* asynchronously so we can move on to the next block
* without delay. Otherwise do a delayed write because we
* may want to write somemore into the block later.
*/
if (ioflag & IO_SYNC)
(void) bwrite(bp);
else if (n + croffset == pmp->pm_bpcluster)
bawrite(bp);
else
bdwrite(bp);
dep->de_flag |= DE_UPDATE;
} while (error == 0 && uio->uio_resid > 0);
/*
* If the write failed and they want us to, truncate the file back
* to the size it was before the write was attempted.
*/
errexit:
if (error) {
if (ioflag & IO_UNIT) {
detrunc(dep, osize, ioflag & IO_SYNC, NOCRED, NULL);
uio->uio_offset -= resid - uio->uio_resid;
uio->uio_resid = resid;
} else {
detrunc(dep, dep->de_FileSize, ioflag & IO_SYNC, NOCRED, NULL);
if (uio->uio_resid != resid)
error = 0;
}
} else if (ioflag & IO_SYNC)
error = deupdat(dep, 1);
return (error);
}
/*
* Flush the blocks of a file to disk.
*
* This function is worthless for vnodes that represent directories. Maybe we
* could just do a sync if they try an fsync on a directory file.
*/
static int
msdosfs_fsync(ap)
struct vop_fsync_args /* {
struct vnode *a_vp;
struct ucred *a_cred;
int a_waitfor;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
int s;
struct buf *bp, *nbp;
/*
* Flush all dirty buffers associated with a vnode.
*/
loop:
s = splbio();
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if ((bp->b_flags & B_BUSY))
continue;
if ((bp->b_flags & B_DELWRI) == 0)
panic("msdosfs_fsync: not dirty");
bremfree(bp);
bp->b_flags |= B_BUSY;
splx(s);
(void) bwrite(bp);
goto loop;
}
while (vp->v_numoutput) {
vp->v_flag |= VBWAIT;
(void) tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "msdosfsn", 0);
}
#ifdef DIAGNOSTIC
if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
vprint("msdosfs_fsync: dirty", vp);
goto loop;
}
#endif
splx(s);
return (deupdat(VTODE(vp), ap->a_waitfor == MNT_WAIT));
}
static int
msdosfs_remove(ap)
struct vop_remove_args /* {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */ *ap;
{
struct denode *dep = VTODE(ap->a_vp);
struct denode *ddep = VTODE(ap->a_dvp);
int error;
if (ap->a_vp->v_type == VDIR)
error = EPERM;
else
error = removede(ddep, dep);
#ifdef MSDOSFS_DEBUG
printf("msdosfs_remove(), dep %p, v_usecount %d\n", dep, ap->a_vp->v_usecount);
#endif
return (error);
}
/*
* DOS filesystems don't know what links are. But since we already called
* msdosfs_lookup() with create and lockparent, the parent is locked so we
* have to free it before we return the error.
*/
static int
msdosfs_link(ap)
struct vop_link_args /* {
struct vnode *a_tdvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */ *ap;
{
VOP_ABORTOP(ap->a_tdvp, ap->a_cnp);
return (EOPNOTSUPP);
}
/*
* Renames on files require moving the denode to a new hash queue since the
* denode's location is used to compute which hash queue to put the file
* in. Unless it is a rename in place. For example "mv a b".
*
* What follows is the basic algorithm:
*
* if (file move) {
* if (dest file exists) {
* remove dest file
* }
* if (dest and src in same directory) {
* rewrite name in existing directory slot
* } else {
* write new entry in dest directory
* update offset and dirclust in denode
* move denode to new hash chain
* clear old directory entry
* }
* } else {
* directory move
* if (dest directory exists) {
* if (dest is not empty) {
* return ENOTEMPTY
* }
* remove dest directory
* }
* if (dest and src in same directory) {
* rewrite name in existing entry
* } else {
* be sure dest is not a child of src directory
* write entry in dest directory
* update "." and ".." in moved directory
* clear old directory entry for moved directory
* }
* }
*
* On entry:
* source's parent directory is unlocked
* source file or directory is unlocked
* destination's parent directory is locked
* destination file or directory is locked if it exists
*
* On exit:
* all denodes should be released
*
* Notes:
* I'm not sure how the memory containing the pathnames pointed at by the
* componentname structures is freed, there may be some memory bleeding
* for each rename done.
*/
static int
msdosfs_rename(ap)
struct vop_rename_args /* {
struct vnode *a_fdvp;
struct vnode *a_fvp;
struct componentname *a_fcnp;
struct vnode *a_tdvp;
struct vnode *a_tvp;
struct componentname *a_tcnp;
} */ *ap;
{
struct vnode *tdvp = ap->a_tdvp;
struct vnode *fvp = ap->a_fvp;
struct vnode *fdvp = ap->a_fdvp;
struct vnode *tvp = ap->a_tvp;
struct componentname *tcnp = ap->a_tcnp;
struct componentname *fcnp = ap->a_fcnp;
struct proc *p = fcnp->cn_proc;
struct denode *ip, *xp, *dp, *zp;
u_char toname[11], oldname[11];
u_long from_diroffset, to_diroffset;
u_char to_count;
int doingdirectory = 0, newparent = 0;
int error;
u_long cn;
daddr_t bn;
struct denode *fddep; /* from file's parent directory */
struct denode *fdep; /* from file or directory */
struct denode *tddep; /* to file's parent directory */
struct denode *tdep; /* to file or directory */
struct msdosfsmount *pmp;
struct direntry *dotdotp;
struct buf *bp;
fddep = VTODE(ap->a_fdvp);
fdep = VTODE(ap->a_fvp);
tddep = VTODE(ap->a_tdvp);
tdep = tvp ? VTODE(tvp) : NULL;
pmp = fddep->de_pmp;
pmp = VFSTOMSDOSFS(fdvp->v_mount);
#ifdef DIAGNOSTIC
if ((tcnp->cn_flags & HASBUF) == 0 ||
(fcnp->cn_flags & HASBUF) == 0)
panic("msdosfs_rename: no name");
#endif
/*
* Check for cross-device rename.
*/
if ((fvp->v_mount != tdvp->v_mount) ||
(tvp && (fvp->v_mount != tvp->v_mount))) {
error = EXDEV;
abortit:
VOP_ABORTOP(tdvp, tcnp);
if (tdvp == tvp)
vrele(tdvp);
else
vput(tdvp);
if (tvp)
vput(tvp);
VOP_ABORTOP(fdvp, fcnp);
vrele(fdvp);
vrele(fvp);
return (error);
}
/*
* If source and dest are the same, do nothing.
*/
if (tvp == fvp) {
error = 0;
goto abortit;
}
error = vn_lock(fvp, LK_EXCLUSIVE, p);
if (error)
goto abortit;
dp = VTODE(fdvp);
ip = VTODE(fvp);
/*
* Be sure we are not renaming ".", "..", or an alias of ".". This
* leads to a crippled directory tree. It's pretty tough to do a
* "ls" or "pwd" with the "." directory entry missing, and "cd .."
* doesn't work if the ".." entry is missing.
*/
if (ip->de_Attributes & ATTR_DIRECTORY) {
/*
* Avoid ".", "..", and aliases of "." for obvious reasons.
*/
if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
dp == ip ||
(fcnp->cn_flags & ISDOTDOT) ||
(tcnp->cn_flags & ISDOTDOT) ||
(ip->de_flag & DE_RENAME)) {
VOP_UNLOCK(fvp, 0, p);
error = EINVAL;
goto abortit;
}
ip->de_flag |= DE_RENAME;
doingdirectory++;
}
/*
* When the target exists, both the directory
* and target vnodes are returned locked.
*/
dp = VTODE(tdvp);
xp = tvp ? VTODE(tvp) : NULL;
/*
* Remember direntry place to use for destination
*/
to_diroffset = dp->de_fndoffset;
to_count = dp->de_fndcnt;
/*
* If ".." must be changed (ie the directory gets a new
* parent) then the source directory must not be in the
* directory heirarchy above the target, as this would
* orphan everything below the source directory. Also
* the user must have write permission in the source so
* as to be able to change "..". We must repeat the call
* to namei, as the parent directory is unlocked by the
* call to doscheckpath().
*/
error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
VOP_UNLOCK(fvp, 0, p);
if (VTODE(fdvp)->de_StartCluster != VTODE(tdvp)->de_StartCluster)
newparent = 1;
vrele(fdvp);
if (doingdirectory && newparent) {
if (error) /* write access check above */
goto bad;
if (xp != NULL)
vput(tvp);
/*
* doscheckpath() vput()'s dp,
* so we have to do a relookup afterwards
*/
error = doscheckpath(ip, dp);
if (error)
goto out;
if ((tcnp->cn_flags & SAVESTART) == 0)
panic("msdosfs_rename: lost to startdir");
error = relookup(tdvp, &tvp, tcnp);
if (error)
goto out;
dp = VTODE(tdvp);
xp = tvp ? VTODE(tvp) : NULL;
}
if (xp != NULL) {
/*
* Target must be empty if a directory and have no links
* to it. Also, ensure source and target are compatible
* (both directories, or both not directories).
*/
if (xp->de_Attributes & ATTR_DIRECTORY) {
if (!dosdirempty(xp)) {
error = ENOTEMPTY;
goto bad;
}
if (!doingdirectory) {
error = ENOTDIR;
goto bad;
}
cache_purge(tdvp);
} else if (doingdirectory) {
error = EISDIR;
goto bad;
}
error = removede(dp, xp);
if (error)
goto bad;
vput(tvp);
xp = NULL;
}
/*
* Convert the filename in tcnp into a dos filename. We copy this
* into the denode and directory entry for the destination
* file/directory.
*/
error = uniqdosname(VTODE(tdvp), tcnp, toname);
if (error)
goto abortit;
/*
* Since from wasn't locked at various places above,
* have to do a relookup here.
*/
fcnp->cn_flags &= ~MODMASK;
fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
if ((fcnp->cn_flags & SAVESTART) == 0)
panic("msdosfs_rename: lost from startdir");
if (!newparent)
VOP_UNLOCK(tdvp, 0, p);
(void) relookup(fdvp, &fvp, fcnp);
if (fvp == NULL) {
/*
* From name has disappeared.
*/
if (doingdirectory)
panic("rename: lost dir entry");
vrele(ap->a_fvp);
if (newparent)
VOP_UNLOCK(tdvp, 0, p);
vrele(tdvp);
return 0;
}
xp = VTODE(fvp);
zp = VTODE(fdvp);
from_diroffset = zp->de_fndoffset;
/*
* Ensure that the directory entry still exists and has not
* changed till now. If the source is a file the entry may
* have been unlinked or renamed. In either case there is
* no further work to be done. If the source is a directory
* then it cannot have been rmdir'ed or renamed; this is
* prohibited by the DE_RENAME flag.
*/
if (xp != ip) {
if (doingdirectory)
panic("rename: lost dir entry");
vrele(ap->a_fvp);
VOP_UNLOCK(fvp, 0, p);
if (newparent)
VOP_UNLOCK(fdvp, 0, p);
xp = NULL;
} else {
vrele(fvp);
xp = NULL;
/*
* First write a new entry in the destination
* directory and mark the entry in the source directory
* as deleted. Then move the denode to the correct hash
* chain for its new location in the filesystem. And, if
* we moved a directory, then update its .. entry to point
* to the new parent directory.
*/
bcopy(ip->de_Name, oldname, 11);
bcopy(toname, ip->de_Name, 11); /* update denode */
dp->de_fndoffset = to_diroffset;
dp->de_fndcnt = to_count;
error = createde(ip, dp, (struct denode **)0, tcnp);
if (error) {
bcopy(oldname, ip->de_Name, 11);
if (newparent)
VOP_UNLOCK(fdvp, 0, p);
VOP_UNLOCK(fvp, 0, p);
goto bad;
}
ip->de_refcnt++;
zp->de_fndoffset = from_diroffset;
error = removede(zp, ip);
if (error) {
/* XXX should really panic here, fs is corrupt */
if (newparent)
VOP_UNLOCK(fdvp, 0, p);
VOP_UNLOCK(fvp, 0, p);
goto bad;
}
if (!doingdirectory) {
error = pcbmap(dp, de_cluster(pmp, to_diroffset), 0,
&ip->de_dirclust, 0);
if (error) {
/* XXX should really panic here, fs is corrupt */
if (newparent)
VOP_UNLOCK(fdvp, 0, p);
VOP_UNLOCK(fvp, 0, p);
goto bad;
}
if (ip->de_dirclust == MSDOSFSROOT)
ip->de_diroffset = to_diroffset;
else
ip->de_diroffset = to_diroffset & pmp->pm_crbomask;
}
reinsert(ip);
if (newparent)
VOP_UNLOCK(fdvp, 0, p);
}
/*
* If we moved a directory to a new parent directory, then we must
* fixup the ".." entry in the moved directory.
*/
if (doingdirectory && newparent) {
cn = ip->de_StartCluster;
if (cn == MSDOSFSROOT) {
/* this should never happen */
panic("msdosfs_rename(): updating .. in root directory?");
} else
bn = cntobn(pmp, cn);
error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
NOCRED, &bp);
if (error) {
/* XXX should really panic here, fs is corrupt */
brelse(bp);
VOP_UNLOCK(fvp, 0, p);
goto bad;
}
dotdotp = (struct direntry *)bp->b_data + 1;
putushort(dotdotp->deStartCluster, dp->de_StartCluster);
if (FAT32(pmp))
putushort(dotdotp->deHighClust, dp->de_StartCluster >> 16);
error = bwrite(bp);
if (error) {
/* XXX should really panic here, fs is corrupt */
VOP_UNLOCK(fvp, 0, p);
goto bad;
}
}
VOP_UNLOCK(fvp, 0, p);
bad:
if (xp)
vput(tvp);
vput(tdvp);
out:
ip->de_flag &= ~DE_RENAME;
vrele(fdvp);
vrele(fvp);
return (error);
}
static struct {
struct direntry dot;
struct direntry dotdot;
} dosdirtemplate = {
{ ". ", " ", /* the . entry */
ATTR_DIRECTORY, /* file attribute */
0, /* reserved */
0, { 0, 0 }, { 0, 0 }, /* create time & date */
{ 0, 0 }, /* access date */
{ 0, 0 }, /* high bits of start cluster */
{ 210, 4 }, { 210, 4 }, /* modify time & date */
{ 0, 0 }, /* startcluster */
{ 0, 0, 0, 0 } /* filesize */
},
{ ".. ", " ", /* the .. entry */
ATTR_DIRECTORY, /* file attribute */
0, /* reserved */
0, { 0, 0 }, { 0, 0 }, /* create time & date */
{ 0, 0 }, /* access date */
{ 0, 0 }, /* high bits of start cluster */
{ 210, 4 }, { 210, 4 }, /* modify time & date */
{ 0, 0 }, /* startcluster */
{ 0, 0, 0, 0 } /* filesize */
}
};
static int
msdosfs_mkdir(ap)
struct vop_mkdir_args /* {
struct vnode *a_dvp;
struvt vnode **a_vpp;
struvt componentname *a_cnp;
struct vattr *a_vap;
} */ *ap;
{
struct componentname *cnp = ap->a_cnp;
struct denode *dep;
struct denode *pdep = VTODE(ap->a_dvp);
struct direntry *denp;
struct msdosfsmount *pmp = pdep->de_pmp;
struct buf *bp;
u_long newcluster, pcl;
int bn;
int error;
struct denode ndirent;
struct timespec ts;
/*
* If this is the root directory and there is no space left we
* can't do anything. This is because the root directory can not
* change size.
*/
if (pdep->de_StartCluster == MSDOSFSROOT
&& pdep->de_fndoffset >= pdep->de_FileSize) {
error = ENOSPC;
goto bad2;
}
/*
* Allocate a cluster to hold the about to be created directory.
*/
error = clusteralloc(pmp, 0, 1, CLUST_EOFE, &newcluster, NULL);
if (error)
goto bad2;
bzero(&ndirent, sizeof(ndirent));
ndirent.de_pmp = pmp;
ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
getnanotime(&ts);
DETIMES(&ndirent, &ts, &ts, &ts);
/*
* Now fill the cluster with the "." and ".." entries. And write
* the cluster to disk. This way it is there for the parent
* directory to be pointing at if there were a crash.
*/
bn = cntobn(pmp, newcluster);
/* always succeeds */
bp = getblk(pmp->pm_devvp, bn, pmp->pm_bpcluster, 0, 0);
bzero(bp->b_data, pmp->pm_bpcluster);
bcopy(&dosdirtemplate, bp->b_data, sizeof dosdirtemplate);
denp = (struct direntry *)bp->b_data;
putushort(denp[0].deStartCluster, newcluster);
putushort(denp[0].deCDate, ndirent.de_CDate);
putushort(denp[0].deCTime, ndirent.de_CTime);
denp[0].deCHundredth = ndirent.de_CHun;
putushort(denp[0].deADate, ndirent.de_ADate);
putushort(denp[0].deMDate, ndirent.de_MDate);
putushort(denp[0].deMTime, ndirent.de_MTime);
pcl = pdep->de_StartCluster;
if (FAT32(pmp) && pcl == pmp->pm_rootdirblk)
pcl = 0;
putushort(denp[1].deStartCluster, pcl);
putushort(denp[1].deCDate, ndirent.de_CDate);
putushort(denp[1].deCTime, ndirent.de_CTime);
denp[1].deCHundredth = ndirent.de_CHun;
putushort(denp[1].deADate, ndirent.de_ADate);
putushort(denp[1].deMDate, ndirent.de_MDate);
putushort(denp[1].deMTime, ndirent.de_MTime);
if (FAT32(pmp)) {
putushort(denp[0].deHighClust, newcluster >> 16);
putushort(denp[1].deHighClust, pdep->de_StartCluster >> 16);
}
error = bwrite(bp);
if (error)
goto bad;
/*
* Now build up a directory entry pointing to the newly allocated
* cluster. This will be written to an empty slot in the parent
* directory.
*/
#ifdef DIAGNOSTIC
if ((cnp->cn_flags & HASBUF) == 0)
panic("msdosfs_mkdir: no name");
#endif
error = uniqdosname(pdep, cnp, ndirent.de_Name);
if (error)
goto bad;
ndirent.de_Attributes = ATTR_DIRECTORY;
ndirent.de_LowerCase = 0;
ndirent.de_StartCluster = newcluster;
ndirent.de_FileSize = 0;
ndirent.de_dev = pdep->de_dev;
ndirent.de_devvp = pdep->de_devvp;
error = createde(&ndirent, pdep, &dep, cnp);
if (error)
goto bad;
if ((cnp->cn_flags & SAVESTART) == 0)
zfree(namei_zone, cnp->cn_pnbuf);
*ap->a_vpp = DETOV(dep);
return (0);
bad:
clusterfree(pmp, newcluster, NULL);
bad2:
zfree(namei_zone, cnp->cn_pnbuf);
return (error);
}
static int
msdosfs_rmdir(ap)
struct vop_rmdir_args /* {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
register struct vnode *dvp = ap->a_dvp;
register struct componentname *cnp = ap->a_cnp;
register struct denode *ip, *dp;
struct proc *p = cnp->cn_proc;
int error;
ip = VTODE(vp);
dp = VTODE(dvp);
/*
* Verify the directory is empty (and valid).
* (Rmdir ".." won't be valid since
* ".." will contain a reference to
* the current directory and thus be
* non-empty.)
*/
error = 0;
if (!dosdirempty(ip) || ip->de_flag & DE_RENAME) {
error = ENOTEMPTY;
goto out;
}
/*
* Delete the entry from the directory. For dos filesystems this
* gets rid of the directory entry on disk, the in memory copy
* still exists but the de_refcnt is <= 0. This prevents it from
* being found by deget(). When the vput() on dep is done we give
* up access and eventually msdosfs_reclaim() will be called which
* will remove it from the denode cache.
*/
error = removede(dp, ip);
if (error)
goto out;
/*
* This is where we decrement the link count in the parent
* directory. Since dos filesystems don't do this we just purge
* the name cache.
*/
cache_purge(dvp);
VOP_UNLOCK(dvp, 0, p);
/*
* Truncate the directory that is being deleted.
*/
error = detrunc(ip, (u_long)0, IO_SYNC, cnp->cn_cred, p);
cache_purge(vp);
vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
out:
return (error);
}
/*
* DOS filesystems don't know what symlinks are.
*/
static int
msdosfs_symlink(ap)
struct vop_symlink_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
char *a_target;
} */ *ap;
{
zfree(namei_zone, ap->a_cnp->cn_pnbuf);
/* VOP_ABORTOP(ap->a_dvp, ap->a_cnp); ??? */
return (EOPNOTSUPP);
}
static int
msdosfs_readdir(ap)
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *a_eofflag;
int *a_ncookies;
u_long **a_cookies;
} */ *ap;
{
int error = 0;
int diff;
long n;
int blsize;
long on;
u_long cn;
u_long fileno;
u_long dirsperblk;
long bias = 0;
daddr_t bn, lbn;
struct buf *bp;
struct denode *dep = VTODE(ap->a_vp);
struct msdosfsmount *pmp = dep->de_pmp;
struct direntry *dentp;
struct dirent dirbuf;
struct uio *uio = ap->a_uio;
u_long *cookies = NULL;
int ncookies = 0;
off_t offset, off;
int chksum = -1;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_readdir(): vp %p, uio %p, cred %p, eofflagp %p\n",
ap->a_vp, uio, ap->a_cred, ap->a_eofflag);
#endif
/*
* msdosfs_readdir() won't operate properly on regular files since
* it does i/o only with the the filesystem vnode, and hence can
* retrieve the wrong block from the buffer cache for a plain file.
* So, fail attempts to readdir() on a plain file.
*/
if ((dep->de_Attributes & ATTR_DIRECTORY) == 0)
return (ENOTDIR);
/*
* To be safe, initialize dirbuf
*/
bzero(dirbuf.d_name, sizeof(dirbuf.d_name));
/*
* If the user buffer is smaller than the size of one dos directory
* entry or the file offset is not a multiple of the size of a
* directory entry, then we fail the read.
*/
off = offset = uio->uio_offset;
if (uio->uio_resid < sizeof(struct direntry) ||
(offset & (sizeof(struct direntry) - 1)))
return (EINVAL);
if (ap->a_ncookies) {
ncookies = uio->uio_resid / 16;
MALLOC(cookies, u_long *, ncookies * sizeof(u_long), M_TEMP,
M_WAITOK);
*ap->a_cookies = cookies;
*ap->a_ncookies = ncookies;
}
dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
/*
* If they are reading from the root directory then, we simulate
* the . and .. entries since these don't exist in the root
* directory. We also set the offset bias to make up for having to
* simulate these entries. By this I mean that at file offset 64 we
* read the first entry in the root directory that lives on disk.
*/
if (dep->de_StartCluster == MSDOSFSROOT
|| (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)) {
#if 0
printf("msdosfs_readdir(): going after . or .. in root dir, offset %d\n",
offset);
#endif
bias = 2 * sizeof(struct direntry);
if (offset < bias) {
for (n = (int)offset / sizeof(struct direntry);
n < 2; n++) {
if (FAT32(pmp))
dirbuf.d_fileno = cntobn(pmp,
pmp->pm_rootdirblk)
* dirsperblk;
else
dirbuf.d_fileno = 1;
dirbuf.d_type = DT_DIR;
switch (n) {
case 0:
dirbuf.d_namlen = 1;
strcpy(dirbuf.d_name, ".");
break;
case 1:
dirbuf.d_namlen = 2;
strcpy(dirbuf.d_name, "..");
break;
}
dirbuf.d_reclen = GENERIC_DIRSIZ(&dirbuf);
if (uio->uio_resid < dirbuf.d_reclen)
goto out;
error = uiomove((caddr_t) &dirbuf,
dirbuf.d_reclen, uio);
if (error)
goto out;
offset += sizeof(struct direntry);
off = offset;
if (cookies) {
*cookies++ = offset;
if (--ncookies <= 0)
goto out;
}
}
}
}
off = offset;
while (uio->uio_resid > 0) {
lbn = de_cluster(pmp, offset - bias);
on = (offset - bias) & pmp->pm_crbomask;
n = min(pmp->pm_bpcluster - on, uio->uio_resid);
diff = dep->de_FileSize - (offset - bias);
if (diff <= 0)
break;
n = min(n, diff);
error = pcbmap(dep, lbn, &bn, &cn, &blsize);
if (error)
break;
error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
if (error) {
brelse(bp);
return (error);
}
n = min(n, blsize - bp->b_resid);
/*
* Convert from dos directory entries to fs-independent
* directory entries.
*/
for (dentp = (struct direntry *)(bp->b_data + on);
(char *)dentp < bp->b_data + on + n;
dentp++, offset += sizeof(struct direntry)) {
#if 0
printf("rd: dentp %08x prev %08x crnt %08x deName %02x attr %02x\n",
dentp, prev, crnt, dentp->deName[0], dentp->deAttributes);
#endif
/*
* If this is an unused entry, we can stop.
*/
if (dentp->deName[0] == SLOT_EMPTY) {
brelse(bp);
goto out;
}
/*
* Skip deleted entries.
*/
if (dentp->deName[0] == SLOT_DELETED) {
chksum = -1;
continue;
}
/*
* Handle Win95 long directory entries
*/
if (dentp->deAttributes == ATTR_WIN95) {
if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
continue;
chksum = win2unixfn((struct winentry *)dentp,
&dirbuf, chksum,
pmp->pm_flags & MSDOSFSMNT_U2WTABLE,
pmp->pm_u2w);
continue;
}
/*
* Skip volume labels
*/
if (dentp->deAttributes & ATTR_VOLUME) {
chksum = -1;
continue;
}
/*
* This computation of d_fileno must match
* the computation of va_fileid in
* msdosfs_getattr.
*/
if (dentp->deAttributes & ATTR_DIRECTORY) {
fileno = getushort(dentp->deStartCluster);
if (FAT32(pmp))
fileno |= getushort(dentp->deHighClust) << 16;
/* if this is the root directory */
if (fileno == MSDOSFSROOT)
if (FAT32(pmp))
fileno = cntobn(pmp,
pmp->pm_rootdirblk)
* dirsperblk;
else
fileno = 1;
else
fileno = cntobn(pmp, fileno) * dirsperblk;
dirbuf.d_fileno = fileno;
dirbuf.d_type = DT_DIR;
} else {
dirbuf.d_fileno = offset / sizeof(struct direntry);
dirbuf.d_type = DT_REG;
}
if (chksum != winChksum(dentp->deName))
dirbuf.d_namlen = dos2unixfn(dentp->deName,
(u_char *)dirbuf.d_name,
dentp->deLowerCase |
((pmp->pm_flags & MSDOSFSMNT_SHORTNAME) ?
(LCASE_BASE | LCASE_EXT) : 0),
pmp->pm_flags & MSDOSFSMNT_U2WTABLE,
pmp->pm_d2u,
pmp->pm_flags & MSDOSFSMNT_ULTABLE,
pmp->pm_ul);
else
dirbuf.d_name[dirbuf.d_namlen] = 0;
chksum = -1;
dirbuf.d_reclen = GENERIC_DIRSIZ(&dirbuf);
if (uio->uio_resid < dirbuf.d_reclen) {
brelse(bp);
goto out;
}
error = uiomove((caddr_t) &dirbuf,
dirbuf.d_reclen, uio);
if (error) {
brelse(bp);
goto out;
}
if (cookies) {
*cookies++ = offset + sizeof(struct direntry);
if (--ncookies <= 0) {
brelse(bp);
goto out;
}
}
off = offset + sizeof(struct direntry);
}
brelse(bp);
}
out:
/* Subtract unused cookies */
if (ap->a_ncookies)
*ap->a_ncookies -= ncookies;
uio->uio_offset = off;
/*
* Set the eofflag (NFS uses it)
*/
if (ap->a_eofflag)
if (dep->de_FileSize - (offset - bias) <= 0)
*ap->a_eofflag = 1;
else
*ap->a_eofflag = 0;
return (error);
}
static int
msdosfs_abortop(ap)
struct vop_abortop_args /* {
struct vnode *a_dvp;
struct componentname *a_cnp;
} */ *ap;
{
if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
zfree(namei_zone, ap->a_cnp->cn_pnbuf);
return (0);
}
/*
* vp - address of vnode file the file
* bn - which cluster we are interested in mapping to a filesystem block number.
* vpp - returns the vnode for the block special file holding the filesystem
* containing the file of interest
* bnp - address of where to return the filesystem relative block number
*/
static int
msdosfs_bmap(ap)
struct vop_bmap_args /* {
struct vnode *a_vp;
daddr_t a_bn;
struct vnode **a_vpp;
daddr_t *a_bnp;
int *a_runp;
int *a_runb;
} */ *ap;
{
struct denode *dep = VTODE(ap->a_vp);
if (ap->a_vpp != NULL)
*ap->a_vpp = dep->de_devvp;
if (ap->a_bnp == NULL)
return (0);
if (ap->a_runp) {
/*
* Sequential clusters should be counted here.
*/
*ap->a_runp = 0;
}
if (ap->a_runb) {
*ap->a_runb = 0;
}
return (pcbmap(dep, ap->a_bn, ap->a_bnp, 0, 0));
}
static int
msdosfs_strategy(ap)
struct vop_strategy_args /* {
struct vnode *a_vp;
struct buf *a_bp;
} */ *ap;
{
struct buf *bp = ap->a_bp;
struct denode *dep = VTODE(bp->b_vp);
struct vnode *vp;
int error = 0;
if (bp->b_vp->v_type == VBLK || bp->b_vp->v_type == VCHR)
panic("msdosfs_strategy: spec");
/*
* If we don't already know the filesystem relative block number
* then get it using pcbmap(). If pcbmap() returns the block
* number as -1 then we've got a hole in the file. DOS filesystems
* don't allow files with holes, so we shouldn't ever see this.
*/
if (bp->b_blkno == bp->b_lblkno) {
error = pcbmap(dep, bp->b_lblkno, &bp->b_blkno, 0, 0);
if (error) {
bp->b_error = error;
bp->b_flags |= B_ERROR;
biodone(bp);
return (error);
}
if ((long)bp->b_blkno == -1)
vfs_bio_clrbuf(bp);
}
if (bp->b_blkno == -1) {
biodone(bp);
return (0);
}
/*
* Read/write the block from/to the disk that contains the desired
* file block.
*/
vp = dep->de_devvp;
bp->b_dev = vp->v_rdev;
VOP_STRATEGY(vp, bp);
return (0);
}
static int
msdosfs_print(ap)
struct vop_print_args /* {
struct vnode *vp;
} */ *ap;
{
struct denode *dep = VTODE(ap->a_vp);
printf(
"tag VT_MSDOSFS, startcluster %lu, dircluster %lu, diroffset %lu ",
dep->de_StartCluster, dep->de_dirclust, dep->de_diroffset);
printf(" dev %d, %d", major(dep->de_dev), minor(dep->de_dev));
lockmgr_printinfo(&dep->de_lock);
printf("\n");
return (0);
}
static int
msdosfs_pathconf(ap)
struct vop_pathconf_args /* {
struct vnode *a_vp;
int a_name;
int *a_retval;
} */ *ap;
{
struct msdosfsmount *pmp = VTODE(ap->a_vp)->de_pmp;
switch (ap->a_name) {
case _PC_LINK_MAX:
*ap->a_retval = 1;
return (0);
case _PC_NAME_MAX:
*ap->a_retval = pmp->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12;
return (0);
case _PC_PATH_MAX:
*ap->a_retval = PATH_MAX;
return (0);
case _PC_CHOWN_RESTRICTED:
*ap->a_retval = 1;
return (0);
case _PC_NO_TRUNC:
*ap->a_retval = 0;
return (0);
default:
return (EINVAL);
}
/* NOTREACHED */
}
/*
* get page routine
*
* XXX By default, wimp out... note that a_offset is ignored (and always
* XXX has been).
*/
int
msdosfs_getpages(ap)
struct vop_getpages_args *ap;
{
return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
ap->a_reqpage);
}
/*
* put page routine
*
* XXX By default, wimp out... note that a_offset is ignored (and always
* XXX has been).
*/
int
msdosfs_putpages(ap)
struct vop_putpages_args *ap;
{
return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
ap->a_sync, ap->a_rtvals);
}
/* Global vfs data structures for msdosfs */
vop_t **msdosfs_vnodeop_p;
static struct vnodeopv_entry_desc msdosfs_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_defaultop },
{ &vop_abortop_desc, (vop_t *) msdosfs_abortop },
{ &vop_access_desc, (vop_t *) msdosfs_access },
{ &vop_bmap_desc, (vop_t *) msdosfs_bmap },
{ &vop_cachedlookup_desc, (vop_t *) msdosfs_lookup },
{ &vop_close_desc, (vop_t *) msdosfs_close },
{ &vop_create_desc, (vop_t *) msdosfs_create },
{ &vop_fsync_desc, (vop_t *) msdosfs_fsync },
{ &vop_getattr_desc, (vop_t *) msdosfs_getattr },
{ &vop_inactive_desc, (vop_t *) msdosfs_inactive },
{ &vop_islocked_desc, (vop_t *) vop_stdislocked },
{ &vop_link_desc, (vop_t *) msdosfs_link },
{ &vop_lock_desc, (vop_t *) vop_stdlock },
{ &vop_lookup_desc, (vop_t *) vfs_cache_lookup },
{ &vop_mkdir_desc, (vop_t *) msdosfs_mkdir },
{ &vop_mknod_desc, (vop_t *) msdosfs_mknod },
{ &vop_pathconf_desc, (vop_t *) msdosfs_pathconf },
{ &vop_print_desc, (vop_t *) msdosfs_print },
{ &vop_read_desc, (vop_t *) msdosfs_read },
{ &vop_readdir_desc, (vop_t *) msdosfs_readdir },
{ &vop_reclaim_desc, (vop_t *) msdosfs_reclaim },
{ &vop_remove_desc, (vop_t *) msdosfs_remove },
{ &vop_rename_desc, (vop_t *) msdosfs_rename },
{ &vop_rmdir_desc, (vop_t *) msdosfs_rmdir },
{ &vop_setattr_desc, (vop_t *) msdosfs_setattr },
{ &vop_strategy_desc, (vop_t *) msdosfs_strategy },
{ &vop_symlink_desc, (vop_t *) msdosfs_symlink },
{ &vop_unlock_desc, (vop_t *) vop_stdunlock },
{ &vop_write_desc, (vop_t *) msdosfs_write },
{ &vop_getpages_desc, (vop_t *) msdosfs_getpages },
{ &vop_putpages_desc, (vop_t *) msdosfs_putpages },
{ NULL, NULL }
};
static struct vnodeopv_desc msdosfs_vnodeop_opv_desc =
{ &msdosfs_vnodeop_p, msdosfs_vnodeop_entries };
VNODEOP_SET(msdosfs_vnodeop_opv_desc);
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