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| Current File : //usr/src/sys/fs/msdosfs/msdosfs_denode.c |
/* $FreeBSD: release/9.1.0/sys/fs/msdosfs/msdosfs_denode.c 232283 2012-02-29 01:36:00Z kib $ */
/* $NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 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/buf.h>
#include <sys/clock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_extern.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>
static MALLOC_DEFINE(M_MSDOSFSNODE, "msdosfs_node", "MSDOSFS vnode private part");
static int
de_vncmpf(struct vnode *vp, void *arg)
{
struct denode *de;
uint64_t *a;
a = arg;
de = VTODE(vp);
return (de->de_inode != *a);
}
/*
* If deget() succeeds it returns with the gotten denode locked().
*
* pmp - address of msdosfsmount structure of the filesystem containing
* the denode of interest. 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 */
u_long dirclust; /* cluster this dir entry came from */
u_long diroffset; /* index of entry within the cluster */
struct denode **depp; /* returns the addr of the gotten denode */
{
int error;
uint64_t inode;
struct mount *mntp = pmp->pm_mountp;
struct direntry *direntptr;
struct denode *ldep;
struct vnode *nvp, *xvp;
struct buf *bp;
#ifdef MSDOSFS_DEBUG
printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\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.
*/
inode = (uint64_t)pmp->pm_bpcluster * dirclust + diroffset;
error = vfs_hash_get(mntp, inode, LK_EXCLUSIVE, curthread, &nvp,
de_vncmpf, &inode);
if (error)
return (error);
if (nvp != NULL) {
*depp = VTODE(nvp);
KASSERT((*depp)->de_dirclust == dirclust, ("wrong dirclust"));
KASSERT((*depp)->de_diroffset == diroffset, ("wrong diroffset"));
return (0);
}
/*
* Do the malloc before the getnewvnode since doing so afterward
* might cause a bogus v_data pointer to get dereferenced
* elsewhere if malloc should block.
*/
ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO);
/*
* 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("msdosfs", mntp, &msdosfs_vnodeops, &nvp);
if (error) {
*depp = NULL;
free(ldep, M_MSDOSFSNODE);
return error;
}
nvp->v_data = ldep;
ldep->de_vnode = nvp;
ldep->de_flag = 0;
ldep->de_dirclust = dirclust;
ldep->de_diroffset = diroffset;
ldep->de_inode = inode;
lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL);
fc_purge(ldep, 0); /* init the fat cache for this denode */
error = insmntque(nvp, mntp);
if (error != 0) {
free(ldep, M_MSDOSFSNODE);
*depp = NULL;
return (error);
}
error = vfs_hash_insert(nvp, inode, LK_EXCLUSIVE, curthread, &xvp,
de_vncmpf, &inode);
if (error) {
*depp = NULL;
return (error);
}
if (xvp != NULL) {
*depp = xvp->v_data;
return (0);
}
ldep->de_pmp = pmp;
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_vflag |= VV_ROOT; /* should be further down XXX */
ldep->de_Attributes = ATTR_DIRECTORY;
ldep->de_LowerCase = 0;
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 * DEV_BSIZE;
}
/*
* fill in time and date so that fattime2timespec() doesn't
* spit up when called from msdosfs_getattr() with root
* denode
*/
ldep->de_CHun = 0;
ldep->de_CTime = 0x0000; /* 00:00:00 */
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) {
/*
* The denode does not contain anything useful, so
* it would be wrong to leave it on its hash chain.
* Arrange for vput() to just forget about it.
*/
ldep->de_Name[0] = SLOT_DELETED;
vput(nvp);
*depp = NULL;
return (error);
}
(void)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.
*/
u_long size;
/*
* XXX it sometimes happens that the "." entry has cluster
* number 0 when it shouldn't. Use the actual cluster number
* instead of what is written in directory entry.
*/
if (diroffset == 0 && ldep->de_StartCluster != dirclust) {
#ifdef MSDOSFS_DEBUG
printf("deget(): \".\" entry at clust %lu != %lu\n",
dirclust, ldep->de_StartCluster);
#endif
ldep->de_StartCluster = dirclust;
}
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 {
#ifdef MSDOSFS_DEBUG
printf("deget(): pcbmap returned %d\n", error);
#endif
}
}
} else
nvp->v_type = VREG;
ldep->de_modrev = init_va_filerev();
*depp = ldep;
return (0);
}
int
deupdat(dep, waitfor)
struct denode *dep;
int waitfor;
{
int error;
struct buf *bp;
struct direntry *dirp;
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, td)
struct denode *dep;
u_long length;
int flags;
struct ucred *cred;
struct thread *td;
{
int error;
int allerror;
u_long eofentry;
u_long chaintofree;
daddr_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 %lu, flags %x\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_vflag & VV_ROOT) && !FAT32(pmp)) {
#ifdef MSDOSFS_DEBUG
printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
dep->de_dirclust, dep->de_diroffset);
#endif
return (EINVAL);
}
if (dep->de_FileSize < length) {
vnode_pager_setsize(DETOV(dep), 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);
if (error) {
brelse(bp);
#ifdef MSDOSFS_DEBUG
printf("detrunc(): bread fails %d\n", error);
#endif
return (error);
}
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;
allerror = vtruncbuf(DETOV(dep), cred, td, length, pmp->pm_bpcluster);
#ifdef MSDOSFS_DEBUG
if (allerror)
printf("detrunc(): vtruncbuf error %d\n", allerror);
#endif
error = deupdat(dep, !DOINGASYNC((DETOV(dep))));
if (error != 0 && allerror == 0)
allerror = error;
#ifdef MSDOSFS_DEBUG
printf("detrunc(): allerror %d, eofentry %lu\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;
u_long length;
struct ucred *cred;
{
struct msdosfsmount *pmp = dep->de_pmp;
u_long count;
int error;
/*
* The root of a DOS filesystem cannot be extended.
*/
if ((DETOV(dep)->v_vflag & VV_ROOT) && !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, !DOINGASYNC(DETOV(dep))));
}
/*
* 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;
{
struct vnode *vp;
/*
* 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 0
if (dep->de_Attributes & ATTR_DIRECTORY)
return;
#endif
vp = DETOV(dep);
dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust +
dep->de_diroffset;
vfs_hash_rehash(vp, dep->de_inode);
}
int
msdosfs_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(vp);
#ifdef MSDOSFS_DEBUG
printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
dep, dep->de_Name, dep->de_refcnt);
#endif
/*
* Destroy the vm object and flush associated pages.
*/
vnode_destroy_vobject(vp);
/*
* Remove the denode from its hash chain.
*/
vfs_hash_remove(vp);
/*
* Purge old data structures associated with the denode.
*/
#if 0 /* XXX */
dep->de_flag = 0;
#endif
free(dep, M_MSDOSFSNODE);
vp->v_data = NULL;
return (0);
}
int
msdosfs_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(vp);
struct thread *td = ap->a_td;
int error = 0;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
#endif
/*
* Ignore denodes related to stale file handles.
*/
if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
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 %p, refcnt %ld, 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, (u_long) 0, 0, NOCRED, td);
dep->de_flag |= DE_UPDATE;
dep->de_Name[0] = SLOT_DELETED;
}
deupdat(dep, 0);
out:
/*
* 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",
vrefcnt(vp), dep->de_Name[0]);
#endif
if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
vrecycle(vp, td);
return (error);
}