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dc22f85f34
freebsd-dev/sys/msdosfs/msdosfs_vnops.c
Boris Popov dc22f85f34 Fix an overflow in the msdosfs_read() function which exposed on the files 
with size > 2GB.

PR:		15639
Submitted by:	Tim Kientzle <kientzle@acm.org>
Reviewed by:	phk
1999-12-28 15:34:23 +00:00

1963 lines
52 KiB
C
Raw Blame History

/* $FreeBSD$ */
/* $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 <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_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;
*ap->a_vpp = DETOV(dep);
return (0);
bad:
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:
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 = dev2udev(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;
off_t diff;
int blsize;
int isadir;
int orig_resid;
long n;
long on;
daddr_t lbn;
daddr_t rablock;
int rasize;
int seqcount;
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 (uio->uio_offset < 0)
return (EINVAL);
/*
* If they didn't ask for any data, then we are done.
*/
orig_resid = uio->uio_resid;
if (orig_resid <= 0)
return (0);
seqcount = ap->a_ioflag >> 16;
isadir = dep->de_Attributes & ATTR_DIRECTORY;
do {
if (uio->uio_offset >= dep->de_FileSize)
break;
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 < n)
n = diff;
/* convert cluster # to block # if a directory */
if (isadir) {
error = pcbmap(dep, lbn, &lbn, 0, &blsize);
if (error)
break;
}
/*
* 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 (seqcount > 1 &&
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);
}
}
n = min(n, pmp->pm_bpcluster - bp->b_resid);
if (error) {
brelse(bp);
break;
}
error = uiomove(bp->b_data + on, (int) n, uio);
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
if (!isadir && (error == 0 || uio->uio_resid != orig_resid) &&
(vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
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 (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
continue;
if ((bp->b_flags & B_DELWRI) == 0)
panic("msdosfs_fsync: not dirty");
bremfree(bp);
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;
{
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:
if (tdvp == tvp)
vrele(tdvp);
else
vput(tdvp);
if (tvp)
vput(tvp);
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;
*ap->a_vpp = DETOV(dep);
return (0);
bad:
clusterfree(pmp, newcluster, NULL);
bad2:
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;
{
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);
}
/*
* 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_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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