diff options
author | dfr <dfr@FreeBSD.org> | 1994-09-19 15:41:57 +0000 |
---|---|---|
committer | dfr <dfr@FreeBSD.org> | 1994-09-19 15:41:57 +0000 |
commit | 7efbb964fdff1348e01bdcd7d4bb59551c389bef (patch) | |
tree | 4ee90f451b7756bcd74bbc0c7e0ef0219507ff02 /sys/msdosfs/msdosfs_denode.c | |
parent | 7a224749be53b3a6bdb826ffbd93208f0b757586 (diff) | |
download | FreeBSD-src-7efbb964fdff1348e01bdcd7d4bb59551c389bef.zip FreeBSD-src-7efbb964fdff1348e01bdcd7d4bb59551c389bef.tar.gz |
Added msdosfs.
Obtained from: NetBSD
Diffstat (limited to 'sys/msdosfs/msdosfs_denode.c')
-rw-r--r-- | sys/msdosfs/msdosfs_denode.c | 689 |
1 files changed, 689 insertions, 0 deletions
diff --git a/sys/msdosfs/msdosfs_denode.c b/sys/msdosfs/msdosfs_denode.c new file mode 100644 index 0000000..6812863 --- /dev/null +++ b/sys/msdosfs/msdosfs_denode.c @@ -0,0 +1,689 @@ +/* $Id$ */ +/* $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/kernel.h> /* defines "time" */ + +#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) (((dev) + (deno)) & dehash) + +int msdosfs_init() +{ + dehashtbl = hashinit(desiredvnodes/2, M_MSDOSFSMNT, &dehash); + return 0; +} + +static struct denode * +msdosfs_hashget(dev, dirclust, diroff) + dev_t dev; + u_long dirclust; + u_long diroff; +{ + struct denode *dep; + + 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) + continue; + if (dep->de_flag & DE_LOCKED) { + dep->de_flag |= DE_WANTED; + sleep((caddr_t)dep, PINOD); + break; + } + if (!vget(DETOV(dep), 1)) + return dep; + break; + } + /* NOTREACHED */ +} + +static void +msdosfs_hashins(dep) + struct denode *dep; +{ + struct denode **depp, *deq; + + depp = &dehashtbl[DEHASH(dep->de_dev, dep->de_dirclust + dep->de_diroffset)]; + if (deq = *depp) + deq->de_prev = &dep->de_next; + dep->de_next = deq; + dep->de_prev = depp; + *depp = dep; + if (dep->de_flag & DE_LOCKED) + panic("msdosfs_hashins: already locked"); + if (curproc) + dep->de_lockholder = curproc->p_pid; + else + dep->de_lockholder = -1; + dep->de_flag |= DE_LOCKED; +} + +static void +msdosfs_hashrem(dep) + struct denode *dep; +{ + struct denode *deq; + if (deq = dep->de_next) + 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 + * 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; + extern int (**msdosfs_vnodeop_p)(); + struct denode *ldep; + struct vnode *nvp; + struct buf *bp; + +#ifdef MSDOSFS_DEBUG + printf("deget(pmp %08x, dirclust %d, diroffset %x, direntptr %x, depp %08x)\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. + */ + if (ldep = msdosfs_hashget(dev, dirclust, diroffset)) { + *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 */ + if (error = getnewvnode(VT_MSDOSFS, mntp, msdosfs_vnodeop_p, &nvp)) { + *depp = 0; + return error; + } + MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK); + bzero((caddr_t)ldep, sizeof *ldep); + 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 */ + + /* + * 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. + */ + 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; + VREF(ldep->de_devvp); + *depp = ldep; + return 0; +} + +int +deupdat(dep, tp, waitfor) + struct denode *dep; + struct timespec *tp; + int waitfor; +{ + int error; + daddr_t bn; + int diro; + struct buf *bp; + struct direntry *dirp; + struct msdosfsmount *pmp = dep->de_pmp; + struct timespec ts; + struct vnode *vp = DETOV(dep); + +#ifdef MSDOSFS_DEBUG + printf("deupdat(): dep %08x\n", dep); +#endif + + /* + * If the update bit is 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_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. + */ + if (error = readde(dep, &bp, &dirp)) + return error; + + /* + * Put the passed in time into the directory entry. + */ + TIMEVAL_TO_TIMESPEC(&time, &ts); + unix2dostime(&ts, &dep->de_Date, &dep->de_Time); + dep->de_flag &= ~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; + +#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 %d, offset %d\n", + dep->de_dirclust, dep->de_diroffset); + return EINVAL; + } + + vnode_pager_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 { + if (error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, &eofentry)) { +#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); + 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; + } + vnode_pager_uncache(DETOV(dep)); /* what's this for? */ + /* + * 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); + allerror = deupdat(dep, &time, 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; + + /* + * 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) { + if (error = suser(cred, NULL)) + 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; + if (error = extendfile(dep, count, NULL, NULL, DE_CLEAR)) { + /* 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; + return deupdat(dep, &time, 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; +{ + union dehead *deh; + + /* + * 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); + int i; + extern int prtactive; + +#ifdef MSDOSFS_DEBUG + printf("msdosfs_reclaim(): dep %08x, file %s, refcnt %d\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; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + struct denode *dep = VTODE(vp); + int error = 0; + extern int prtactive; + +#ifdef MSDOSFS_DEBUG + printf("msdosfs_inactive(): dep %08x, de_Name[0] %x\n", dep, dep->de_Name[0]); +#endif + + if (prtactive && vp->v_usecount != 0) + vprint("msdosfs_inactive(): pushing active", vp); + + /* + * Get rid of denodes related to stale file handles. Hmmm, what + * does this really do? + */ + if (dep->de_Name[0] == SLOT_DELETED) { + if ((vp->v_flag & VXLOCK) == 0) + vgone(vp); + return 0; + } + + /* + * 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 + VOP_LOCK(vp); + if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { + error = detrunc(dep, (u_long) 0, 0, NOCRED, NULL); + dep->de_flag |= DE_UPDATE; + dep->de_Name[0] = SLOT_DELETED; + } + DE_UPDAT(dep, &time, 0); + VOP_UNLOCK(vp); + 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 (vp->v_usecount == 0 && dep->de_Name[0] == SLOT_DELETED) + vgone(vp); + return error; +} |