freebsd-dev/sys/fs/msdosfs/msdosfs_denode.c
John Dyson 89721f6f1a This is a trial improvement for the vnode reference count while on the vnode
free list problem.  Also, the vnode age flag is no longer used by the
vnode pager.  (It is actually incorrect to use then.)  Constructive
feedback welcome -- just be kind.
1997-08-22 03:56:37 +00:00

759 lines
20 KiB
C

/* $Id: msdosfs_denode.c,v 1.23 1997/02/26 14:23:11 bde Exp $ */
/* $NetBSD: msdosfs_denode.c,v 1.9 1994/08/21 18:44:00 ws Exp $ */
/*-
* Copyright (C) 1994 Wolfgang Solfrank.
* Copyright (C) 1994 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/types.h>
#include <sys/kernel.h> /* defines "time" */
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_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, deno) (dehashtbl[((dev) + (deno)) & dehash])
static struct simplelock dehash_slock;
union _qcvt {
quad_t qcvt;
long val[2];
};
#define SETHIGH(q, h) { \
union _qcvt tmp; \
tmp.qcvt = (q); \
tmp.val[_QUAD_HIGHWORD] = (h); \
(q) = tmp.qcvt; \
}
#define SETLOW(q, l) { \
union _qcvt tmp; \
tmp.qcvt = (q); \
tmp.val[_QUAD_LOWWORD] = (l); \
(q) = tmp.qcvt; \
}
static struct denode *
msdosfs_hashget __P((dev_t dev, u_long dirclust,
u_long diroff));
static void msdosfs_hashins __P((struct denode *dep));
static void msdosfs_hashrem __P((struct denode *dep));
int msdosfs_init(vfsp)
struct vfsconf *vfsp;
{
dehashtbl = hashinit(desiredvnodes/2, M_MSDOSFSMNT, &dehash);
simple_lock_init(&dehash_slock);
return 0;
}
static struct denode *
msdosfs_hashget(dev, dirclust, diroff)
dev_t dev;
u_long dirclust;
u_long diroff;
{
struct proc *p = curproc; /* XXX */
struct denode *dep;
struct vnode *vp;
loop:
simple_lock(&dehash_slock);
for (dep = DEHASH(dev, dirclust + diroff); dep; dep = dep->de_next) {
if (dirclust == dep->de_dirclust
&& diroff == dep->de_diroffset
&& dev == dep->de_dev
&& dep->de_refcnt != 0) {
vp = DETOV(dep);
simple_lock(&vp->v_interlock);
simple_unlock(&dehash_slock);
if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p))
goto loop;
return (dep);
}
}
simple_unlock(&dehash_slock);
return (NULL);
}
static void
msdosfs_hashins(dep)
struct denode *dep;
{
struct denode **depp, *deq;
simple_lock(&dehash_slock);
depp = &DEHASH(dep->de_dev, dep->de_dirclust + dep->de_diroffset);
deq = *depp;
if (deq)
deq->de_prev = &dep->de_next;
dep->de_next = deq;
dep->de_prev = depp;
*depp = dep;
simple_unlock(&dehash_slock);
}
static void
msdosfs_hashrem(dep)
struct denode *dep;
{
struct denode *deq;
simple_lock(&dehash_slock);
deq = dep->de_next;
if (deq)
deq->de_prev = dep->de_prev;
*dep->de_prev = deq;
#ifdef DIAGNOSTIC
dep->de_next = NULL;
dep->de_prev = NULL;
#endif
simple_unlock(&dehash_slock);
}
/*
* 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
* direntptr - address of the direntry structure of interest. If direntptr is
* NULL, the block is read if necessary.
* depp - returns the address of the gotten denode.
*/
int
deget(pmp, dirclust, diroffset, direntptr, 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 direntry *direntptr;
struct denode **depp; /* returns the addr of the gotten denode */
{
int error;
dev_t dev = pmp->pm_dev;
struct mount *mntp = pmp->pm_mountp;
struct denode *ldep;
struct vnode *nvp;
struct buf *bp;
struct proc *p = curproc; /* XXX */
#ifdef MSDOSFS_DEBUG
printf("deget(pmp %p, dirclust %ld, diroffset %x, direntptr %p, depp %p)\n",
pmp, dirclust, diroffset, direntptr, depp);
#endif
/*
* If dir entry is given and refers to a directory, convert to
* canonical form
*/
if (direntptr && (direntptr->deAttributes & ATTR_DIRECTORY)) {
dirclust = getushort(direntptr->deStartCluster);
if (dirclust == MSDOSFSROOT)
diroffset = MSDOSFSROOT_OFS;
else
diroffset = 0;
}
/*
* 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 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.
*/
ldep = msdosfs_hashget(dev, dirclust, diroffset);
if (ldep) {
*depp = ldep;
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.
*/
MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK);
/*
* 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, mntp, msdosfs_vnodeop_p, &nvp);
if (error) {
*depp = NULL;
FREE(ldep, M_MSDOSFSNODE);
return error;
}
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 = dev;
ldep->de_dirclust = dirclust;
ldep->de_diroffset = diroffset;
fc_purge(ldep, 0); /* init the fat cache for this denode */
/*
* Lock the denode so that it can't be accessed until we've read
* it in and have done what we need to it. Do this here instead
* of at the start of msdosfs_hashins() so that reinsert() can
* call msdosfs_hashins() with a locked denode.
*/
if (lockmgr(&ldep->de_lock, LK_EXCLUSIVE, (struct simplelock *)0, p))
panic("deget: unexpected lock failure");
/*
* Insert the denode into the hash queue.
*/
msdosfs_hashins(ldep);
/*
* Copy the directory entry into the denode area of the vnode.
*/
if (dirclust == MSDOSFSROOT && 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.
*/
ldep->de_Attributes = ATTR_DIRECTORY;
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_Time = 0x0000; /* 00:00:00 */
ldep->de_Date = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
| (1 << DD_DAY_SHIFT);
/* Jan 1, 1980 */
/* leave the other fields as garbage */
} else {
bp = NULL;
if (!direntptr) {
error = readep(pmp, dirclust, diroffset, &bp,
&direntptr);
if (error)
return error;
}
DE_INTERNALIZE(ldep, direntptr);
if (bp)
brelse(bp);
}
/*
* Fill in a few fields of the vnode and finish filling in the
* denode. Then return the address of the found denode.
*/
ldep->de_pmp = pmp;
ldep->de_devvp = pmp->pm_devvp;
ldep->de_refcnt = 1;
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;
nvp->v_type = VDIR;
if (ldep->de_StartCluster == MSDOSFSROOT)
nvp->v_flag |= VROOT;
else {
error = pcbmap(ldep, 0xffff, 0, &size);
if (error == E2BIG) {
ldep->de_FileSize = size << pmp->pm_cnshift;
error = 0;
} else
printf("deget(): pcbmap returned %d\n", error);
}
} else
nvp->v_type = VREG;
SETHIGH(ldep->de_modrev, mono_time.tv_sec);
SETLOW(ldep->de_modrev, mono_time.tv_usec * 4294);
VREF(ldep->de_devvp);
*depp = ldep;
return 0;
}
int
deupdat(dep, tp, waitfor)
struct denode *dep;
struct timespec *tp;
int waitfor;
{
int error;
struct buf *bp;
struct direntry *dirp;
struct vnode *vp = DETOV(dep);
#ifdef MSDOSFS_DEBUG
printf("deupdat(): dep %p\n", dep);
#endif
/*
* If the denode-modified and update-mtime bits are off,
* or this denode is from a readonly filesystem,
* or this denode is for a directory,
* or the denode represents an open but unlinked file,
* then don't do anything. DOS directory
* entries that describe a directory do not ever get
* updated. This is the way DOS treats them.
*/
if ((dep->de_flag & (DE_MODIFIED | DE_UPDATE)) == 0 ||
vp->v_mount->mnt_flag & MNT_RDONLY ||
dep->de_Attributes & ATTR_DIRECTORY ||
dep->de_refcnt <= 0)
return 0;
/*
* Read in the cluster containing the directory entry we want to
* update.
*/
error = readde(dep, &bp, &dirp);
if (error)
return error;
/*
* If the mtime is to be updated, put the passed in time into the
* directory entry.
*/
if (dep->de_flag & DE_UPDATE) {
dep->de_Attributes |= ATTR_ARCHIVE;
unix2dostime(tp, &dep->de_Date, &dep->de_Time);
}
/*
* The mtime is now up to date. The denode will be unmodifed soon.
*/
dep->de_flag &= ~(DE_MODIFIED | DE_UPDATE);
/*
* Copy the directory entry out of the denode into the cluster it
* came from.
*/
DE_EXTERNALIZE(dirp, dep);
/*
* Write the cluster back to disk. If they asked for us to wait
* for the write to complete, then use bwrite() otherwise use
* bdwrite().
*/
error = 0; /* note that error is 0 from above, but ... */
if (waitfor)
error = bwrite(bp);
else
bdwrite(bp);
return error;
}
/*
* Truncate the file described by dep to the length specified by length.
*/
int
detrunc(dep, length, flags, cred, p)
struct denode *dep;
u_long length;
int flags;
struct ucred *cred;
struct proc *p;
{
int error;
int allerror;
int vflags;
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;
struct timespec ts;
#ifdef MSDOSFS_DEBUG
printf("detrunc(): file %s, length %d, 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) {
printf(
"detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
dep->de_dirclust, dep->de_diroffset);
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);
if (error) {
#ifdef MSDOSFS_DEBUG
printf("detrunc(): pcbmap fails %d\n", error);
#endif
return error;
}
}
fc_purge(dep, (length + pmp->pm_crbomask) >> pmp->pm_cnshift);
/*
* 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) {
/*
* should read from file vnode or filesystem vnode
* depending on if file or dir
*/
if (isadir) {
bn = cntobn(pmp, eofentry);
error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
NOCRED, &bp);
} else {
bn = de_blk(pmp, length);
#ifdef PC98
/*
* 1024 byte/sector support
*/
if (pmp->pm_BytesPerSec == 1024)
DETOV(dep)->v_flag |= 0x10000;
#endif
error = bread(DETOV(dep), bn, pmp->pm_bpcluster,
NOCRED, &bp);
}
if (error) {
#ifdef MSDOSFS_DEBUG
printf("detrunc(): bread fails %d\n", error);
#endif
return error;
}
/*
* 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;
dep->de_flag |= DE_UPDATE;
vflags = (length > 0 ? V_SAVE : 0) | V_SAVEMETA;
vinvalbuf(DETOV(dep), vflags, cred, p, 0, 0);
vnode_pager_setsize(DETOV(dep), length);
TIMEVAL_TO_TIMESPEC(&time, &ts);
allerror = deupdat(dep, &ts, 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, (length - 1) >> pmp->pm_cnshift,
eofentry);
}
/*
* Now free the clusters removed from the file because of the
* truncation.
*/
if (chaintofree != 0 && !MSDOSFSEOF(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;
off_t length;
struct ucred *cred;
{
struct msdosfsmount *pmp = dep->de_pmp;
u_long count;
int error;
struct timespec ts;
/*
* The root of a DOS filesystem cannot be extended.
*/
if (DETOV(dep)->v_flag & VROOT)
return EINVAL;
/*
* Directories can only be extended by the superuser.
* Is this really important?
*/
if (dep->de_Attributes & ATTR_DIRECTORY) {
error = suser(cred, NULL);
if (error)
return error;
}
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_flag |= DE_UPDATE;
dep->de_FileSize = length;
TIMEVAL_TO_TIMESPEC(&time, &ts);
return deupdat(dep, &ts, 1);
}
/*
* Move a denode to its correct hash queue after the file it represents has
* been moved to a new directory.
*/
int 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) == 0) {
msdosfs_hashrem(dep);
msdosfs_hashins(dep);
}
return 0;
}
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
if (prtactive && vp->v_usecount != 0)
vprint("msdosfs_reclaim(): pushing active", vp);
/*
* Remove the denode from the denode hash chain we are in.
*/
msdosfs_hashrem(dep);
cache_purge(vp);
/*
* Indicate that one less file on the filesystem is open.
*/
if (dep->de_devvp) {
vrele(dep->de_devvp);
dep->de_devvp = 0;
}
dep->de_flag = 0;
FREE(dep, M_MSDOSFSNODE);
vp->v_data = NULL;
return 0;
}
int
msdosfs_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct denode *dep = VTODE(vp);
struct proc *p = ap->a_p;
int error = 0;
struct timespec ts;
#ifdef MSDOSFS_DEBUG
printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
#endif
if (prtactive && vp->v_usecount != 0)
vprint("msdosfs_inactive(): pushing active", vp);
/*
* Ignore inodes 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 %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, p);
dep->de_flag |= DE_UPDATE;
dep->de_Name[0] = SLOT_DELETED;
}
if (dep->de_flag & (DE_MODIFIED | DE_UPDATE)) {
TIMEVAL_TO_TIMESPEC(&time, &ts);
deupdat(dep, &ts, 0);
}
out:
VOP_UNLOCK(vp, 0, p);
dep->de_flag = 0;
/*
* If we are done with the denode, then reclaim it so that it can
* be reused now.
*/
#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)
vp->v_flag |= VAGE;
return error;
}