/* $OpenBSD: msdosfs_denode.c,v 1.32 2007/06/02 02:04:21 deraadt Exp $ */
/* $NetBSD: msdosfs_denode.c,v 1.23 1997/10/17 11:23:58 ws Exp $ */
/*-
* Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
* Copyright (C) 1994, 1995, 1997 TooLs GmbH.
* All rights reserved.
* Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/kernel.h> /* defines "time" */
#include <sys/dirent.h>
#include <sys/namei.h>
#include <uvm/uvm_extern.h>
#include <msdosfs/bpb.h>
#include <msdosfs/msdosfsmount.h>
#include <msdosfs/direntry.h>
#include <msdosfs/denode.h>
#include <msdosfs/fat.h>
struct denode **dehashtbl;
u_long dehash; /* size of hash table - 1 */
#define DEHASH(dev, dcl, doff) (((dev) + (dcl) + (doff) / sizeof(struct direntry)) \
& dehash)
static struct denode *msdosfs_hashget(dev_t, uint32_t, uint32_t);
static int msdosfs_hashins(struct denode *);
static void msdosfs_hashrem(struct denode *);
/*ARGSUSED*/
int
msdosfs_init(vfsp)
struct vfsconf *vfsp;
{
dehashtbl = hashinit(desiredvnodes/2, M_MSDOSFSMNT, M_WAITOK, &dehash);
return (0);
}
static struct denode *
msdosfs_hashget(dev, dirclust, diroff)
dev_t dev;
uint32_t dirclust;
uint32_t diroff;
{
struct denode *dep;
struct proc *p = curproc; /* XXX */
for (;;)
for (dep = dehashtbl[DEHASH(dev, dirclust, diroff)];;
dep = dep->de_next) {
if (dep == NULL)
return (NULL);
if (dirclust == dep->de_dirclust &&
diroff == dep->de_diroffset &&
dev == dep->de_dev &&
dep->de_refcnt != 0) {
struct vnode *vp = DETOV(dep);
if (!vget(vp, LK_EXCLUSIVE, p))
return (dep);
break;
}
}
/* NOTREACHED */
}
static int
msdosfs_hashins(dep)
struct denode *dep;
{
struct denode **depp, *deq;
depp = &dehashtbl[DEHASH(dep->de_dev, dep->de_dirclust,
dep->de_diroffset)];
for (deq = *depp; deq; deq = deq->de_next) {
if (dep->de_dirclust == deq->de_dirclust &&
dep->de_diroffset == deq->de_diroffset &&
dep->de_dev == deq->de_dev &&
deq->de_refcnt != 0) {
return (EEXIST);
}
}
if ((deq = *depp) != NULL)
deq->de_prev = &dep->de_next;
dep->de_next = deq;
dep->de_prev = depp;
*depp = dep;
return (0);
}
static void
msdosfs_hashrem(dep)
struct denode *dep;
{
struct denode *deq;
if (dep->de_prev == NULL)
return;
if ((deq = dep->de_next) != NULL)
deq->de_prev = dep->de_prev;
*dep->de_prev = deq;
#ifdef DIAGNOSTIC
dep->de_next = NULL;
dep->de_prev = NULL;
#endif
}
/*
* If deget() succeeds it returns with the gotten denode locked().
*
* pmp - address of msdosfsmount structure of the filesystem containing
* the denode of interest. The pm_dev field and the address of
* the msdosfsmount structure are used.
* dirclust - which cluster bp contains, if dirclust is 0 (root directory)
* diroffset is relative to the beginning of the root directory,
* otherwise it is cluster relative.
* diroffset - offset past begin of cluster of denode we want
* depp - returns the address of the gotten denode.
*/
int
deget(pmp, dirclust, diroffset, depp)
struct msdosfsmount *pmp; /* so we know the maj/min number */
uint32_t dirclust; /* cluster this dir entry came from */
uint32_t diroffset; /* index of entry within the cluster */
struct denode **depp; /* returns the addr of the gotten denode */
{
int error;
extern int (**msdosfs_vnodeop_p)(void *);
struct direntry *direntptr;
struct denode *ldep;
struct vnode *nvp;
struct buf *bp;
struct proc *p = curproc; /* XXX */
#ifdef MSDOSFS_DEBUG
printf("deget(pmp %08x, dirclust %d, diroffset %x, depp %08x)\n",
pmp, dirclust, diroffset, depp);
#endif
/*
* On FAT32 filesystems, root is a (more or less) normal
* directory
*/
if (FAT32(pmp) && dirclust == MSDOSFSROOT)
dirclust = pmp->pm_rootdirblk;
/*
* See if the denode is in the denode cache. Use the location of
* the directory entry to compute the hash value. For subdir use
* address of "." entry. For root dir (if not FAT32) use cluster
* MSDOSFSROOT, offset MSDOSFSROOT_OFS
*
* NOTE: The check for de_refcnt > 0 below insures the denode being
* examined does not represent an unlinked but still open file.
* These files are not to be accessible even when the directory
* entry that represented the file happens to be reused while the
* deleted file is still open.
*/
retry:
ldep = msdosfs_hashget(pmp->pm_dev, dirclust, diroffset);
if (ldep) {
*depp = ldep;
return (0);
}
/*
* Directory entry was not in cache, have to create a vnode and
* copy it from the passed disk buffer.
*/
/* getnewvnode() does a VREF() on the vnode */
error = getnewvnode(VT_MSDOSFS, pmp->pm_mountp,
msdosfs_vnodeop_p, &nvp);
if (error) {
*depp = 0;
return (error);
}
MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE,
M_WAITOK);
bzero((caddr_t)ldep, sizeof *ldep);
lockinit(&ldep->de_lock, PINOD, "denode", 0, 0);
nvp->v_data = ldep;
ldep->de_vnode = nvp;
ldep->de_flag = 0;
ldep->de_devvp = 0;
ldep->de_lockf = 0;
ldep->de_dev = pmp->pm_dev;
ldep->de_dirclust = dirclust;
ldep->de_diroffset = diroffset;
fc_purge(ldep, 0); /* init the fat cache for this denode */
/*
* Insert the denode into the hash queue and lock the denode so it
* can't be accessed until we've read it in and have done what we
* need to it.
*/
vn_lock(nvp, LK_EXCLUSIVE | LK_RETRY, p);
error = msdosfs_hashins(ldep);
if (error) {
vput (nvp);
if (error == EEXIST)
goto retry;
return (error);
}
ldep->de_pmp = pmp;
ldep->de_devvp = pmp->pm_devvp;
ldep->de_refcnt = 1;
/*
* Copy the directory entry into the denode area of the vnode.
*/
if ((dirclust == MSDOSFSROOT
|| (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
&& diroffset == MSDOSFSROOT_OFS) {
/*
* Directory entry for the root directory. There isn't one,
* so we manufacture one. We should probably rummage
* through the root directory and find a label entry (if it
* exists), and then use the time and date from that entry
* as the time and date for the root denode.
*/
nvp->v_flag |= VROOT; /* should be further down XXX */
ldep->de_Attributes = ATTR_DIRECTORY;
if (FAT32(pmp))
ldep->de_StartCluster = pmp->pm_rootdirblk;
/* de_FileSize will be filled in further down */
else {
ldep->de_StartCluster = MSDOSFSROOT;
ldep->de_FileSize = pmp->pm_rootdirsize * pmp->pm_BytesPerSec;
}
/*
* fill in time and date so that dos2unixtime() doesn't
* spit up when called from msdosfs_getattr() with root
* denode
*/
ldep->de_CTime = 0x0000; /* 00:00:00 */
ldep->de_CTimeHundredth = 0;
ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
| (1 << DD_DAY_SHIFT);
/* Jan 1, 1980 */
ldep->de_ADate = ldep->de_CDate;
ldep->de_MTime = ldep->de_CTime;
ldep->de_MDate = ldep->de_CDate;
/* leave the other fields as garbage */
} else {
error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
if (error)
return (error);
DE_INTERNALIZE(ldep, direntptr);
brelse(bp);
}
/*
* Fill in a few fields of the vnode and finish filling in the
* denode. Then return the address of the found denode.
*/
if (ldep->de_Attributes & ATTR_DIRECTORY) {
/*
* Since DOS directory entries that describe directories
* have 0 in the filesize field, we take this opportunity
* to find out the length of the directory and plug it into
* the denode structure.
*/
uint32_t size;
nvp->v_type = VDIR;
if (ldep->de_StartCluster != MSDOSFSROOT) {
error = pcbmap(ldep, 0xffff, 0, &size, 0);
if (error == E2BIG) {
ldep->de_FileSize = de_cn2off(pmp, size);
error = 0;
} else
printf("deget(): pcbmap returned %d\n", error);
}
} else
nvp->v_type = VREG;
VREF(ldep->de_devvp);
*depp = ldep;
return (0);
}
int
deupdat(dep, waitfor)
struct denode *dep;
int waitfor;
{
struct buf *bp;
struct direntry *dirp;
int error;
struct timespec ts;
if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY)
return (0);
getnanotime(&ts);
DETIMES(dep, &ts, &ts, &ts);
if ((dep->de_flag & DE_MODIFIED) == 0)
return (0);
dep->de_flag &= ~DE_MODIFIED;
if (dep->de_Attributes & ATTR_DIRECTORY)
return (0);
if (dep->de_refcnt <= 0)
return (0);
error = readde(dep, &bp, &dirp);
if (error)
return (error);
DE_EXTERNALIZE(dirp, dep);
if (waitfor)
return (bwrite(bp));
else {
bdwrite(bp);
return (0);
}
}
/*
* Truncate the file described by dep to the length specified by length.
*/
int
detrunc(dep, length, flags, cred, p)
struct denode *dep;
uint32_t length;
int flags;
struct ucred *cred;
struct proc *p;
{
int error;
int allerror;
int vflags;
uint32_t eofentry;
uint32_t chaintofree;
daddr64_t bn;
int boff;
int isadir = dep->de_Attributes & ATTR_DIRECTORY;
struct buf *bp;
struct msdosfsmount *pmp = dep->de_pmp;
#ifdef MSDOSFS_DEBUG
printf("detrunc(): file %s, length %ld, flags %d\n", dep->de_Name, length, flags);
#endif
/*
* Disallow attempts to truncate the root directory since it is of
* fixed size. That's just the way dos filesystems are. We use
* the VROOT bit in the vnode because checking for the directory
* bit and a startcluster of 0 in the denode is not adequate to
* recognize the root directory at this point in a file or
* directory's life.
*/
if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) {
printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
dep->de_dirclust, dep->de_diroffset);
return (EINVAL);
}
uvm_vnp_setsize(DETOV(dep), length);
if (dep->de_FileSize < length)
return (deextend(dep, length, cred));
/*
* If the desired length is 0 then remember the starting cluster of
* the file and set the StartCluster field in the directory entry
* to 0. If the desired length is not zero, then get the number of
* the last cluster in the shortened file. Then get the number of
* the first cluster in the part of the file that is to be freed.
* Then set the next cluster pointer in the last cluster of the
* file to CLUST_EOFE.
*/
if (length == 0) {
chaintofree = dep->de_StartCluster;
dep->de_StartCluster = 0;
eofentry = ~0;
} else {
error = pcbmap(dep, de_clcount(pmp, length) - 1, 0,
&eofentry, 0);
if (error) {
#ifdef MSDOSFS_DEBUG
printf("detrunc(): pcbmap fails %d\n", error);
#endif
return (error);
}
}
fc_purge(dep, de_clcount(pmp, length));
/*
* If the new length is not a multiple of the cluster size then we
* must zero the tail end of the new last cluster in case it
* becomes part of the file again because of a seek.
*/
if ((boff = length & pmp->pm_crbomask) != 0) {
if (isadir) {
bn = cntobn(pmp, eofentry);
error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
NOCRED, &bp);
} else {
bn = de_blk(pmp, length);
error = bread(DETOV(dep), bn, pmp->pm_bpcluster,
NOCRED, &bp);
}
if (error) {
brelse(bp);
#ifdef MSDOSFS_DEBUG
printf("detrunc(): bread fails %d\n", error);
#endif
return (error);
}
uvm_vnp_uncache(DETOV(dep));
/*
* is this the right place for it?
*/
bzero(bp->b_data + boff, pmp->pm_bpcluster - boff);
if (flags & IO_SYNC)
bwrite(bp);
else
bdwrite(bp);
}
/*
* Write out the updated directory entry. Even if the update fails
* we free the trailing clusters.
*/
dep->de_FileSize = length;
if (!isadir)
dep->de_flag |= DE_UPDATE|DE_MODIFIED;
vflags = (length > 0 ? V_SAVE : 0) | V_SAVEMETA;
vinvalbuf(DETOV(dep), vflags, cred, p, 0, 0);
allerror = deupdat(dep, 1);
#ifdef MSDOSFS_DEBUG
printf("detrunc(): allerror %d, eofentry %d\n",
allerror, eofentry);
#endif
/*
* If we need to break the cluster chain for the file then do it
* now.
*/
if (eofentry != ~0) {
error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
&chaintofree, CLUST_EOFE);
if (error) {
#ifdef MSDOSFS_DEBUG
printf("detrunc(): fatentry errors %d\n", error);
#endif
return (error);
}
fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
eofentry);
}
/*
* Now free the clusters removed from the file because of the
* truncation.
*/
if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
freeclusterchain(pmp, chaintofree);
return (allerror);
}
/*
* Extend the file described by dep to length specified by length.
*/
int
deextend(dep, length, cred)
struct denode *dep;
uint32_t length;
struct ucred *cred;
{
struct msdosfsmount *pmp = dep->de_pmp;
uint32_t count;
int error;
/*
* The root of a DOS filesystem cannot be extended.
*/
if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp))
return (EINVAL);
/*
* Directories cannot be extended.
*/
if (dep->de_Attributes & ATTR_DIRECTORY)
return (EISDIR);
if (length <= dep->de_FileSize)
panic("deextend: file too large");
/*
* Compute the number of clusters to allocate.
*/
count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
if (count > 0) {
if (count > pmp->pm_freeclustercount)
return (ENOSPC);
error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
if (error) {
/* truncate the added clusters away again */
(void) detrunc(dep, dep->de_FileSize, 0, cred, NULL);
return (error);
}
}
dep->de_FileSize = length;
dep->de_flag |= DE_UPDATE|DE_MODIFIED;
return (deupdat(dep, 1));
}
/*
* Move a denode to its correct hash queue after the file it represents has
* been moved to a new directory.
*/
void
reinsert(dep)
struct denode *dep;
{
/*
* Fix up the denode cache. If the denode is for a directory,
* there is nothing to do since the hash is based on the starting
* cluster of the directory file and that hasn't changed. If for a
* file the hash is based on the location of the directory entry,
* so we must remove it from the cache and re-enter it with the
* hash based on the new location of the directory entry.
*/
if (dep->de_Attributes & ATTR_DIRECTORY)
return;
msdosfs_hashrem(dep);
msdosfs_hashins(dep);
}
int
msdosfs_reclaim(v)
void *v;
{
struct vop_reclaim_args *ap = v;
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(vp);
#ifdef DIAGNOSTIC
extern int prtactive;
if (prtactive && vp->v_usecount != 0)
vprint("msdosfs_reclaim(): pushing active", vp);
#endif
#ifdef MSDOSFS_DEBUG
printf("msdosfs_reclaim(): dep %08x, file %s, refcnt %d\n",
dep, dep->de_Name, dep->de_refcnt);
#endif
/*
* Remove the denode from its hash chain.
*/
msdosfs_hashrem(dep);
/*
* Purge old data structures associated with the denode.
*/
cache_purge(vp);
if (dep->de_devvp) {
vrele(dep->de_devvp);
dep->de_devvp = 0;
}
#if 0 /* XXX */
dep->de_flag = 0;
#endif
FREE(dep, M_MSDOSFSNODE);
vp->v_data = NULL;
return (0);
}
int
msdosfs_inactive(v)
void *v;
{
struct vop_inactive_args *ap = v;
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(vp);
struct proc *p = ap->a_p;
int error;
#ifdef DIAGNOSTIC
extern int prtactive;
if (prtactive && vp->v_usecount != 0)
vprint("msdosfs_inactive(): pushing active", vp);
#endif
#ifdef MSDOSFS_DEBUG
printf("msdosfs_inactive(): dep %08x, de_Name[0] %x\n", dep, dep->de_Name[0]);
#endif
error = 0;
/*
* Get rid of denodes related to stale file handles.
*/
if (dep->de_Name[0] == SLOT_DELETED)
goto out;
/*
* If the file has been deleted and it is on a read/write
* filesystem, then truncate the file, and mark the directory slot
* as empty. (This may not be necessary for the dos filesystem.)
*/
#ifdef MSDOSFS_DEBUG
printf("msdosfs_inactive(): dep %08x, refcnt %d, mntflag %x, MNT_RDONLY %x\n",
dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
#endif
if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
error = detrunc(dep, (uint32_t)0, 0, NOCRED, NULL);
dep->de_Name[0] = SLOT_DELETED;
}
deupdat(dep, 0);
out:
VOP_UNLOCK(vp, 0, p);
/*
* If we are done with the denode, reclaim it
* so that it can be reused immediately.
*/
#ifdef MSDOSFS_DEBUG
printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", vp->v_usecount,
dep->de_Name[0]);
#endif
if (dep->de_Name[0] == SLOT_DELETED)
vrecycle(vp, p);
return (error);
}
![[BACK]](/icons/back.gif){kind=icon}
Return to msdosfs_denode.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / sys / msdosfs