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60965b7606
freebsd-nq/sys/fs/msdosfs/msdosfs_vnops.c
Conrad Meyer 60965b7606 msdosfs(5): Reflect READONLY attribute in file mode 
Msdosfs allows setting READONLY by clearing the owner write bit of the file
mode.  (While here, correct the misspelling of S_IWUSR as VWRITE.  No
functional change.)

In msdosfs_getattr, intuitively reflect that READONLY attribute to userspace
in the file mode.

Reported by:	Karl Denninger <karl AT denninger.net>
Sponsored by:	Dell EMC Isilon
2017-11-20 21:38:24 +00:00

1940 lines
52 KiB
C
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/* $FreeBSD$ */
/* $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/bio.h>
#include <sys/buf.h>
#include <sys/clock.h>
#include <sys/dirent.h>
#include <sys/lock.h>
#include <sys/lockf.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vnode_pager.h>
#include <fs/msdosfs/bpb.h>
#include <fs/msdosfs/direntry.h>
#include <fs/msdosfs/denode.h>
#include <fs/msdosfs/fat.h>
#include <fs/msdosfs/msdosfsmount.h>
#define DOS_FILESIZE_MAX 0xffffffff
/*
* Prototypes for MSDOSFS vnode operations
*/
static vop_create_t msdosfs_create;
static vop_mknod_t msdosfs_mknod;
static vop_open_t msdosfs_open;
static vop_close_t msdosfs_close;
static vop_access_t msdosfs_access;
static vop_getattr_t msdosfs_getattr;
static vop_setattr_t msdosfs_setattr;
static vop_read_t msdosfs_read;
static vop_write_t msdosfs_write;
static vop_fsync_t msdosfs_fsync;
static vop_remove_t msdosfs_remove;
static vop_link_t msdosfs_link;
static vop_rename_t msdosfs_rename;
static vop_mkdir_t msdosfs_mkdir;
static vop_rmdir_t msdosfs_rmdir;
static vop_symlink_t msdosfs_symlink;
static vop_readdir_t msdosfs_readdir;
static vop_bmap_t msdosfs_bmap;
static vop_getpages_t msdosfs_getpages;
static vop_strategy_t msdosfs_strategy;
static vop_print_t msdosfs_print;
static vop_pathconf_t msdosfs_pathconf;
static vop_vptofh_t msdosfs_vptofh;
/*
* 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
* retrieve 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(struct vop_create_args *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
memset(&ndirent, 0, sizeof(ndirent));
error = uniqdosname(pdep, cnp, ndirent.de_Name);
if (error)
goto bad;
ndirent.de_Attributes = ATTR_ARCHIVE;
ndirent.de_LowerCase = 0;
ndirent.de_StartCluster = 0;
ndirent.de_FileSize = 0;
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);
if ((cnp->cn_flags & MAKEENTRY) != 0)
cache_enter(ap->a_dvp, *ap->a_vpp, cnp);
return (0);
bad:
return (error);
}
static int
msdosfs_mknod(struct vop_mknod_args *ap)
{
return (EINVAL);
}
static int
msdosfs_open(struct vop_open_args *ap)
{
struct denode *dep = VTODE(ap->a_vp);
vnode_create_vobject(ap->a_vp, dep->de_FileSize, ap->a_td);
return 0;
}
static int
msdosfs_close(struct vop_close_args *ap)
{
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(vp);
struct timespec ts;
VI_LOCK(vp);
if (vp->v_usecount > 1) {
getnanotime(&ts);
DETIMES(dep, &ts, &ts, &ts);
}
VI_UNLOCK(vp);
return 0;
}
static int
msdosfs_access(struct vop_access_args *ap)
{
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(ap->a_vp);
struct msdosfsmount *pmp = dep->de_pmp;
mode_t file_mode;
accmode_t accmode = ap->a_accmode;
file_mode = S_IRWXU|S_IRWXG|S_IRWXO;
file_mode &= (vp->v_type == VDIR ? pmp->pm_dirmask : pmp->pm_mask);
/*
* Disallow writing to directories and regular files if the
* filesystem is read-only.
*/
if (accmode & VWRITE) {
switch (vp->v_type) {
case VREG:
case VDIR:
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
break;
default:
break;
}
}
return (vaccess(vp->v_type, file_mode, pmp->pm_uid, pmp->pm_gid,
ap->a_accmode, ap->a_cred, NULL));
}
static int
msdosfs_getattr(struct vop_getattr_args *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);
uint64_t fileid;
getnanotime(&ts);
DETIMES(dep, &ts, &ts, &ts);
vap->va_fsid = dev2udev(pmp->pm_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 = (uint64_t)cntobn(pmp, dep->de_StartCluster) *
dirsperblk;
if (dep->de_StartCluster == MSDOSFSROOT)
fileid = 1;
} else {
fileid = (uint64_t)cntobn(pmp, dep->de_dirclust) *
dirsperblk;
if (dep->de_dirclust == MSDOSFSROOT)
fileid = (uint64_t)roottobn(pmp, 0) * dirsperblk;
fileid += (uoff_t)dep->de_diroffset / sizeof(struct direntry);
}
vap->va_fileid = fileid;
mode = S_IRWXU|S_IRWXG|S_IRWXO;
if (dep->de_Attributes & ATTR_READONLY)
mode &= ~(S_IWUSR|S_IWGRP|S_IWOTH);
vap->va_mode = mode &
(ap->a_vp->v_type == VDIR ? pmp->pm_dirmask : pmp->pm_mask);
vap->va_uid = pmp->pm_uid;
vap->va_gid = pmp->pm_gid;
vap->va_nlink = 1;
vap->va_rdev = NODEV;
vap->va_size = dep->de_FileSize;
fattime2timespec(dep->de_MDate, dep->de_MTime, 0, 0, &vap->va_mtime);
vap->va_ctime = vap->va_mtime;
if (pmp->pm_flags & MSDOSFSMNT_LONGNAME) {
fattime2timespec(dep->de_ADate, 0, 0, 0, &vap->va_atime);
fattime2timespec(dep->de_CDate, dep->de_CTime, dep->de_CHun,
0, &vap->va_birthtime);
} else {
vap->va_atime = vap->va_mtime;
vap->va_birthtime.tv_sec = -1;
vap->va_birthtime.tv_nsec = 0;
}
vap->va_flags = 0;
if (dep->de_Attributes & ATTR_ARCHIVE)
vap->va_flags |= UF_ARCHIVE;
if (dep->de_Attributes & ATTR_HIDDEN)
vap->va_flags |= UF_HIDDEN;
if (dep->de_Attributes & ATTR_READONLY)
vap->va_flags |= UF_READONLY;
if (dep->de_Attributes & ATTR_SYSTEM)
vap->va_flags |= UF_SYSTEM;
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(struct vop_setattr_args *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;
struct thread *td = curthread;
int error = 0;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_setattr(): vp %p, vap %p, cred %p\n",
ap->a_vp, vap, cred);
#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 %llx, va_fsid %llx, va_fileid %llx\n",
vap->va_type, (unsigned long long)vap->va_nlink,
(unsigned long long)vap->va_fsid,
(unsigned long long)vap->va_fileid);
printf(" va_blocksize %lx, va_rdev %llx, va_bytes %llx, va_gen %lx\n",
vap->va_blocksize, (unsigned long long)vap->va_rdev,
(unsigned long long)vap->va_bytes, vap->va_gen);
printf(" va_uid %x, va_gid %x\n",
vap->va_uid, vap->va_gid);
#endif
return (EINVAL);
}
/*
* We don't allow setting attributes on the root directory.
* The special case for the root directory is because before
* FAT32, the root directory didn't have an entry for itself
* (and was otherwise special). With FAT32, the root
* directory is not so special, but still doesn't have an
* entry for itself.
*/
if (vp->v_vflag & VV_ROOT)
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 = priv_check_cred(cred, PRIV_VFS_ADMIN, 0);
if (error)
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.
*/
if (vap->va_flags & ~(UF_ARCHIVE | UF_HIDDEN | UF_READONLY |
UF_SYSTEM))
return EOPNOTSUPP;
if (vap->va_flags & UF_ARCHIVE)
dep->de_Attributes |= ATTR_ARCHIVE;
else
dep->de_Attributes &= ~ATTR_ARCHIVE;
if (vap->va_flags & UF_HIDDEN)
dep->de_Attributes |= ATTR_HIDDEN;
else
dep->de_Attributes &= ~ATTR_HIDDEN;
/* We don't allow changing the readonly bit on directories. */
if (vp->v_type != VDIR) {
if (vap->va_flags & UF_READONLY)
dep->de_Attributes |= ATTR_READONLY;
else
dep->de_Attributes &= ~ATTR_READONLY;
}
if (vap->va_flags & UF_SYSTEM)
dep->de_Attributes |= ATTR_SYSTEM;
else
dep->de_Attributes &= ~ATTR_SYSTEM;
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 = priv_check_cred(cred, PRIV_VFS_CHOWN, 0);
if (error)
return (error);
}
if (uid != pmp->pm_uid || gid != pmp->pm_gid)
return EINVAL;
}
if (vap->va_size != VNOVAL) {
switch (vp->v_type) {
case VDIR:
return (EISDIR);
case VREG:
/*
* Truncation is only supported for regular files,
* Disallow it if the filesystem is read-only.
*/
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
break;
default:
/*
* According to POSIX, the result is unspecified
* for file types other than regular files,
* directories and shared memory objects. We
* don't support any file types except regular
* files and directories in this file system, so
* this (default) case is unreachable and can do
* anything. Keep falling through to detrunc()
* for now.
*/
break;
}
error = detrunc(dep, vap->va_size, 0, cred);
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);
error = vn_utimes_perm(vp, vap, cred, td);
if (error != 0)
return (error);
if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) == 0 &&
vap->va_atime.tv_sec != VNOVAL) {
dep->de_flag &= ~DE_ACCESS;
timespec2fattime(&vap->va_atime, 0,
&dep->de_ADate, NULL, NULL);
}
if (vap->va_mtime.tv_sec != VNOVAL) {
dep->de_flag &= ~DE_UPDATE;
timespec2fattime(&vap->va_mtime, 0,
&dep->de_MDate, &dep->de_MTime, NULL);
}
/*
* We don't set the archive bit when modifying the time of
* a directory to emulate the Windows/DOS behavior.
*/
if (vp->v_type != VDIR)
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 = priv_check_cred(cred, PRIV_VFS_ADMIN, 0);
if (error)
return (error);
}
if (vp->v_type != VDIR) {
/* We ignore the read and execute bits. */
if (vap->va_mode & S_IWUSR)
dep->de_Attributes &= ~ATTR_READONLY;
else
dep->de_Attributes |= ATTR_READONLY;
dep->de_Attributes |= ATTR_ARCHIVE;
dep->de_flag |= DE_MODIFIED;
}
}
return (deupdat(dep, 0));
}
static int
msdosfs_read(struct vop_read_args *ap)
{
int error = 0;
int blsize;
int isadir;
ssize_t orig_resid;
u_int n;
u_long diff;
u_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 they didn't ask for any data, then we are done.
*/
orig_resid = uio->uio_resid;
if (orig_resid == 0)
return (0);
/*
* The caller is supposed to ensure that
* uio->uio_offset >= 0 and uio->uio_resid >= 0.
* We don't need to check for large offsets as in ffs because
* dep->de_FileSize <= DOS_FILESIZE_MAX < OFF_MAX, so large
* offsets cannot cause overflow even in theory.
*/
seqcount = ap->a_ioflag >> IO_SEQSHIFT;
isadir = dep->de_Attributes & ATTR_DIRECTORY;
do {
if (uio->uio_offset >= dep->de_FileSize)
break;
lbn = de_cluster(pmp, uio->uio_offset);
rablock = lbn + 1;
blsize = pmp->pm_bpcluster;
on = uio->uio_offset & pmp->pm_crbomask;
/*
* 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) {
/* convert cluster # to block # */
error = pcbmap(dep, lbn, &lbn, 0, &blsize);
if (error == E2BIG) {
error = EINVAL;
break;
} else if (error)
break;
error = bread(pmp->pm_devvp, lbn, blsize, NOCRED, &bp);
} else if (de_cn2off(pmp, rablock) >= dep->de_FileSize) {
error = bread(vp, lbn, blsize, NOCRED, &bp);
} else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
error = cluster_read(vp, dep->de_FileSize, lbn, blsize,
NOCRED, on + uio->uio_resid, seqcount, 0, &bp);
} else if (seqcount > 1) {
rasize = blsize;
error = breadn(vp, lbn,
blsize, &rablock, &rasize, 1, NOCRED, &bp);
} else {
error = bread(vp, lbn, blsize, NOCRED, &bp);
}
if (error) {
brelse(bp);
break;
}
diff = pmp->pm_bpcluster - on;
n = diff > uio->uio_resid ? uio->uio_resid : diff;
diff = dep->de_FileSize - uio->uio_offset;
if (diff < n)
n = diff;
diff = blsize - bp->b_resid;
if (diff < n)
n = diff;
error = vn_io_fault_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 | MNT_RDONLY)) == 0)
dep->de_flag |= DE_ACCESS;
return (error);
}
/*
* Write data to a file or directory.
*/
static int
msdosfs_write(struct vop_write_args *ap)
{
int n;
int croffset;
ssize_t resid;
u_long osize;
int error = 0;
u_long count;
int seqcount;
daddr_t bn, lastcn;
struct buf *bp;
int ioflag = ap->a_ioflag;
struct uio *uio = ap->a_uio;
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");
}
/*
* This is needed (unlike in ffs_write()) because we extend the
* file outside of the loop but we don't want to extend the file
* for writes of 0 bytes.
*/
if (uio->uio_resid == 0)
return (0);
/*
* The caller is supposed to ensure that
* uio->uio_offset >= 0 and uio->uio_resid >= 0.
*/
if ((uoff_t)uio->uio_offset + uio->uio_resid > DOS_FILESIZE_MAX)
return (EFBIG);
/*
* If they've exceeded their filesize limit, tell them about it.
*/
if (vn_rlimit_fsize(vp, uio, uio->uio_td))
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;
seqcount = ioflag >> IO_SEQSHIFT;
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, 0);
/*
* This call to vfs_bio_clrbuf() ensures that
* even if vn_io_fault_uiomove() below faults,
* garbage from the newly instantiated buffer
* is not exposed to the userspace via mmap().
*/
vfs_bio_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, &bn, 0, 0);
if (error)
bp->b_blkno = -1;
else
bp->b_blkno = bn;
}
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 = vn_io_fault_uiomove(bp->b_data + croffset, n, uio);
if (error) {
brelse(bp);
break;
}
/* Prepare for clustered writes in some else clauses. */
if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0)
bp->b_flags |= B_CLUSTEROK;
/*
* If IO_SYNC, then each buffer is written synchronously.
* Otherwise, if we have a severe page deficiency then
* write the buffer asynchronously. Otherwise, if on a
* cluster boundary then write the buffer asynchronously,
* combining it with contiguous clusters if permitted and
* possible, since we don't expect more writes into this
* buffer soon. Otherwise, do a delayed write because we
* expect more writes into this buffer soon.
*/
if (ioflag & IO_SYNC)
(void)bwrite(bp);
else if (vm_page_count_severe() || buf_dirty_count_severe())
bawrite(bp);
else if (n + croffset == pmp->pm_bpcluster) {
if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0)
cluster_write(vp, bp, dep->de_FileSize,
seqcount, 0);
else
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);
uio->uio_offset -= resid - uio->uio_resid;
uio->uio_resid = resid;
} else {
detrunc(dep, dep->de_FileSize, ioflag & IO_SYNC, NOCRED);
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.
*/
static int
msdosfs_fsync(struct vop_fsync_args *ap)
{
struct vnode *devvp;
int allerror, error;
vop_stdfsync(ap);
/*
* If the syncing request comes from fsync(2), sync the entire
* FAT and any other metadata that happens to be on devvp. We
* need this mainly for the FAT. We write the FAT sloppily, and
* syncing it all now is the best we can easily do to get all
* directory entries associated with the file (not just the file)
* fully synced. The other metadata includes critical metadata
* for all directory entries, but only in the MNT_ASYNC case. We
* will soon sync all metadata in the file's directory entry.
* Non-critical metadata for associated directory entries only
* gets synced accidentally, as in most file systems.
*/
if (ap->a_waitfor == MNT_WAIT) {
devvp = VTODE(ap->a_vp)->de_pmp->pm_devvp;
vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
allerror = VOP_FSYNC(devvp, MNT_WAIT, ap->a_td);
VOP_UNLOCK(devvp, 0);
} else
allerror = 0;
error = deupdat(VTODE(ap->a_vp), ap->a_waitfor == MNT_WAIT);
if (allerror == 0)
allerror = error;
return (allerror);
}
static int
msdosfs_remove(struct vop_remove_args *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.
*/
static int
msdosfs_link(struct vop_link_args *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
*/
static int
msdosfs_rename(struct vop_rename_args *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 denode *ip, *xp, *dp, *zp;
u_char toname[12], oldname[11];
u_long from_diroffset, to_diroffset;
u_char to_count;
int doingdirectory = 0, newparent = 0;
int error;
u_long cn, pcl;
daddr_t bn;
struct msdosfsmount *pmp;
struct direntry *dotdotp;
struct buf *bp;
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);
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);
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 hierarchy 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_thread);
VOP_UNLOCK(fvp, 0);
if (VTODE(fdvp)->de_StartCluster != VTODE(tdvp)->de_StartCluster)
newparent = 1;
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);
if (relookup(fdvp, &fvp, fcnp) == 0)
vrele(fdvp);
if (fvp == NULL) {
/*
* From name has disappeared.
*/
if (doingdirectory)
panic("rename: lost dir entry");
if (newparent)
VOP_UNLOCK(tdvp, 0);
vrele(tdvp);
vrele(ap->a_fvp);
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");
VOP_UNLOCK(fvp, 0);
if (newparent)
VOP_UNLOCK(fdvp, 0);
vrele(ap->a_fvp);
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.
*/
memcpy(oldname, ip->de_Name, 11);
memcpy(ip->de_Name, toname, 11); /* update denode */
dp->de_fndoffset = to_diroffset;
dp->de_fndcnt = to_count;
error = createde(ip, dp, (struct denode **)0, tcnp);
if (error) {
memcpy(ip->de_Name, oldname, 11);
if (newparent)
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(fvp, 0);
goto bad;
}
/*
* If ip is for a directory, then its name should always
* be "." since it is for the directory entry in the
* directory itself (msdosfs_lookup() always translates
* to the "." entry so as to get a unique denode, except
* for the root directory there are different
* complications). However, we just corrupted its name
* to pass the correct name to createde(). Undo this.
*/
if ((ip->de_Attributes & ATTR_DIRECTORY) != 0)
memcpy(ip->de_Name, oldname, 11);
ip->de_refcnt++;
zp->de_fndoffset = from_diroffset;
error = removede(zp, ip);
if (error) {
/* XXX should downgrade to ro here, fs is corrupt */
if (newparent)
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(fvp, 0);
goto bad;
}
if (!doingdirectory) {
error = pcbmap(dp, de_cluster(pmp, to_diroffset), 0,
&ip->de_dirclust, 0);
if (error) {
/* XXX should downgrade to ro here, fs is corrupt */
if (newparent)
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(fvp, 0);
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);
}
/*
* 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 downgrade to ro here, fs is corrupt */
brelse(bp);
VOP_UNLOCK(fvp, 0);
goto bad;
}
dotdotp = (struct direntry *)bp->b_data + 1;
pcl = dp->de_StartCluster;
if (FAT32(pmp) && pcl == pmp->pm_rootdirblk)
pcl = MSDOSFSROOT;
putushort(dotdotp->deStartCluster, pcl);
if (FAT32(pmp))
putushort(dotdotp->deHighClust, pcl >> 16);
if (DOINGASYNC(fvp))
bdwrite(bp);
else if ((error = bwrite(bp)) != 0) {
/* XXX should downgrade to ro here, fs is corrupt */
VOP_UNLOCK(fvp, 0);
goto bad;
}
}
/*
* The msdosfs lookup is case insensitive. Several aliases may
* be inserted for a single directory entry. As a consequnce,
* name cache purge done by lookup for fvp when DELETE op for
* namei is specified, might be not enough to expunge all
* namecache entries that were installed for this direntry.
*/
cache_purge(fvp);
VOP_UNLOCK(fvp, 0);
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(struct vop_mkdir_args *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;
memset(&ndirent, 0, 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, 0);
memset(bp->b_data, 0, pmp->pm_bpcluster);
memcpy(bp->b_data, &dosdirtemplate, 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;
/*
* Although the root directory has a non-magic starting cluster
* number for FAT32, chkdsk and fsck_msdosfs still require
* references to it in dotdot entries to be magic.
*/
if (FAT32(pmp) && pcl == pmp->pm_rootdirblk)
pcl = MSDOSFSROOT;
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, pcl >> 16);
}
if (DOINGASYNC(ap->a_dvp))
bdwrite(bp);
else if ((error = bwrite(bp)) != 0)
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;
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(struct vop_rmdir_args *ap)
{
struct vnode *vp = ap->a_vp;
struct vnode *dvp = ap->a_dvp;
struct componentname *cnp = ap->a_cnp;
struct denode *ip, *dp;
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);
/*
* Truncate the directory that is being deleted.
*/
error = detrunc(ip, (u_long)0, IO_SYNC, cnp->cn_cred);
cache_purge(vp);
out:
return (error);
}
/*
* DOS filesystems don't know what symlinks are.
*/
static int
msdosfs_symlink(struct vop_symlink_args *ap)
{
return (EOPNOTSUPP);
}
static int
msdosfs_readdir(struct vop_readdir_args *ap)
{
struct mbnambuf nb;
int error = 0;
int diff;
long n;
int blsize;
long on;
u_long cn;
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 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
*/
memset(dirbuf.d_name, 0, 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;
cookies = malloc(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++) {
dirbuf.d_fileno = FAT32(pmp) ?
(uint64_t)cntobn(pmp, pmp->pm_rootdirblk) *
dirsperblk : 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(&dirbuf, dirbuf.d_reclen, uio);
if (error)
goto out;
offset += sizeof(struct direntry);
off = offset;
if (cookies) {
*cookies++ = offset;
if (--ncookies <= 0)
goto out;
}
}
}
}
mbnambuf_init(&nb);
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);
if (n == 0) {
brelse(bp);
return (EIO);
}
/*
* 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;
mbnambuf_init(&nb);
continue;
}
/*
* Handle Win95 long directory entries
*/
if (dentp->deAttributes == ATTR_WIN95) {
if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
continue;
chksum = win2unixfn(&nb,
(struct winentry *)dentp, chksum, pmp);
continue;
}
/*
* Skip volume labels
*/
if (dentp->deAttributes & ATTR_VOLUME) {
chksum = -1;
mbnambuf_init(&nb);
continue;
}
/*
* This computation of d_fileno must match
* the computation of va_fileid in
* msdosfs_getattr.
*/
if (dentp->deAttributes & ATTR_DIRECTORY) {
cn = getushort(dentp->deStartCluster);
if (FAT32(pmp)) {
cn |= getushort(dentp->deHighClust) <<
16;
if (cn == MSDOSFSROOT)
cn = pmp->pm_rootdirblk;
}
if (cn == MSDOSFSROOT && !FAT32(pmp))
dirbuf.d_fileno = 1;
else
dirbuf.d_fileno = cntobn(pmp, cn) *
dirsperblk;
dirbuf.d_type = DT_DIR;
} else {
dirbuf.d_fileno = (uoff_t)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);
mbnambuf_init(&nb);
} else
mbnambuf_flush(&nb, &dirbuf);
chksum = -1;
dirbuf.d_reclen = GENERIC_DIRSIZ(&dirbuf);
if (uio->uio_resid < dirbuf.d_reclen) {
brelse(bp);
goto out;
}
error = uiomove(&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);
}
/*-
* a_vp - pointer to the file's vnode
* a_bn - logical block number within the file (cluster number for us)
* a_bop - where to return the bufobj of the special file containing the fs
* a_bnp - where to return the "physical" block number corresponding to a_bn
* (relative to the special file; units are blocks of size DEV_BSIZE)
* a_runp - where to return the "run past" a_bn. This is the count of logical
* blocks whose physical blocks (together with a_bn's physical block)
* are contiguous.
* a_runb - where to return the "run before" a_bn.
*/
static int
msdosfs_bmap(struct vop_bmap_args *ap)
{
struct denode *dep;
struct mount *mp;
struct msdosfsmount *pmp;
struct vnode *vp;
daddr_t runbn;
u_long cn;
int bnpercn, error, maxio, maxrun, run;
vp = ap->a_vp;
dep = VTODE(vp);
pmp = dep->de_pmp;
if (ap->a_bop != NULL)
*ap->a_bop = &pmp->pm_devvp->v_bufobj;
if (ap->a_bnp == NULL)
return (0);
if (ap->a_runp != NULL)
*ap->a_runp = 0;
if (ap->a_runb != NULL)
*ap->a_runb = 0;
cn = ap->a_bn;
if (cn != ap->a_bn)
return (EFBIG);
error = pcbmap(dep, cn, ap->a_bnp, NULL, NULL);
if (error != 0 || (ap->a_runp == NULL && ap->a_runb == NULL))
return (error);
mp = vp->v_mount;
maxio = mp->mnt_iosize_max / mp->mnt_stat.f_iosize;
bnpercn = de_cn2bn(pmp, 1);
if (ap->a_runp != NULL) {
maxrun = ulmin(maxio - 1, pmp->pm_maxcluster - cn);
for (run = 1; run <= maxrun; run++) {
if (pcbmap(dep, cn + run, &runbn, NULL, NULL) != 0 ||
runbn != *ap->a_bnp + run * bnpercn)
break;
}
*ap->a_runp = run - 1;
}
if (ap->a_runb != NULL) {
maxrun = ulmin(maxio - 1, cn);
for (run = 1; run < maxrun; run++) {
if (pcbmap(dep, cn - run, &runbn, NULL, NULL) != 0 ||
runbn != *ap->a_bnp - run * bnpercn)
break;
}
*ap->a_runb = run - 1;
}
return (0);
}
SYSCTL_NODE(_vfs, OID_AUTO, msdosfs, CTLFLAG_RW, 0, "msdos filesystem");
static int use_buf_pager = 1;
SYSCTL_INT(_vfs_msdosfs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN,
&use_buf_pager, 0,
"Use buffer pager instead of bmap");
static daddr_t
msdosfs_gbp_getblkno(struct vnode *vp, vm_ooffset_t off)
{
return (de_cluster(VTODE(vp)->de_pmp, off));
}
static int
msdosfs_gbp_getblksz(struct vnode *vp, daddr_t lbn)
{
return (VTODE(vp)->de_pmp->pm_bpcluster);
}
static int
msdosfs_getpages(struct vop_getpages_args *ap)
{
if (use_buf_pager)
return (vfs_bio_getpages(ap->a_vp, ap->a_m, ap->a_count,
ap->a_rbehind, ap->a_rahead, msdosfs_gbp_getblkno,
msdosfs_gbp_getblksz));
return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
ap->a_rbehind, ap->a_rahead, NULL, NULL));
}
static int
msdosfs_strategy(struct vop_strategy_args *ap)
{
struct buf *bp = ap->a_bp;
struct denode *dep = VTODE(ap->a_vp);
struct bufobj *bo;
int error = 0;
daddr_t blkno;
/*
* 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, &blkno, 0, 0);
bp->b_blkno = blkno;
if (error) {
bp->b_error = error;
bp->b_ioflags |= BIO_ERROR;
bufdone(bp);
return (0);
}
if ((long)bp->b_blkno == -1)
vfs_bio_clrbuf(bp);
}
if (bp->b_blkno == -1) {
bufdone(bp);
return (0);
}
/*
* Read/write the block from/to the disk that contains the desired
* file block.
*/
bp->b_iooffset = dbtob(bp->b_blkno);
bo = dep->de_pmp->pm_bo;
BO_STRATEGY(bo, bp);
return (0);
}
static int
msdosfs_print(struct vop_print_args *ap)
{
struct denode *dep = VTODE(ap->a_vp);
printf("\tstartcluster %lu, dircluster %lu, diroffset %lu, ",
dep->de_StartCluster, dep->de_dirclust, dep->de_diroffset);
printf("on dev %s\n", devtoname(dep->de_pmp->pm_dev));
return (0);
}
static int
msdosfs_pathconf(struct vop_pathconf_args *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_NO_TRUNC:
*ap->a_retval = 0;
return (0);
default:
return (vop_stdpathconf(ap));
}
/* NOTREACHED */
}
static int
msdosfs_vptofh(struct vop_vptofh_args *ap)
{
struct denode *dep;
struct defid *defhp;
dep = VTODE(ap->a_vp);
defhp = (struct defid *)ap->a_fhp;
defhp->defid_len = sizeof(struct defid);
defhp->defid_dirclust = dep->de_dirclust;
defhp->defid_dirofs = dep->de_diroffset;
/* defhp->defid_gen = dep->de_gen; */
return (0);
}
/* Global vfs data structures for msdosfs */
struct vop_vector msdosfs_vnodeops = {
.vop_default = &default_vnodeops,
.vop_access = msdosfs_access,
.vop_bmap = msdosfs_bmap,
.vop_getpages = msdosfs_getpages,
.vop_cachedlookup = msdosfs_lookup,
.vop_open = msdosfs_open,
.vop_close = msdosfs_close,
.vop_create = msdosfs_create,
.vop_fsync = msdosfs_fsync,
.vop_fdatasync = vop_stdfdatasync_buf,
.vop_getattr = msdosfs_getattr,
.vop_inactive = msdosfs_inactive,
.vop_link = msdosfs_link,
.vop_lookup = vfs_cache_lookup,
.vop_mkdir = msdosfs_mkdir,
.vop_mknod = msdosfs_mknod,
.vop_pathconf = msdosfs_pathconf,
.vop_print = msdosfs_print,
.vop_read = msdosfs_read,
.vop_readdir = msdosfs_readdir,
.vop_reclaim = msdosfs_reclaim,
.vop_remove = msdosfs_remove,
.vop_rename = msdosfs_rename,
.vop_rmdir = msdosfs_rmdir,
.vop_setattr = msdosfs_setattr,
.vop_strategy = msdosfs_strategy,
.vop_symlink = msdosfs_symlink,
.vop_write = msdosfs_write,
.vop_vptofh = msdosfs_vptofh,
};
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