/* $NetBSD: msdosfs_denode.c,v 1.12 1995/04/07 17:37:08 mycroft 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 #include #include #include #include #include #include #include /* defines "time" */ #include #include #include #include #include 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); } 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) { if (dep->de_flag & DE_LOCKED) { dep->de_flag |= DE_WANTED; sleep(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; } 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; 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(pmp->pm_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, pmp->pm_mountp, 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 = 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. */ VOP_LOCK(nvp); 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; struct buf *bp; struct direntry *dirp; 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. */ unix2dostime(tp, &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 %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) { printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\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) { 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, NULL, 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) { if (error = fatentry(FAT_GET_AND_SET, pmp, eofentry, &chaintofree, CLUST_EOFE)) { #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; 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_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, (u_short *)0)) 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, NULL, 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; { struct denode **depp, *deq; /* * 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(ap) struct vop_reclaim_args /* { struct vnode *a_vp; } */ *ap; { struct vnode *vp = ap->a_vp; struct denode *dep = VTODE(vp); 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 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(ap) struct vop_inactive_args /* { struct vnode *a_vp; } */ *ap; { struct vnode *vp = ap->a_vp; struct denode *dep = VTODE(vp); int error; 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. */ if (dep->de_Name[0] == SLOT_DELETED) { if ((vp->v_flag & VXLOCK) == 0) vgone(vp); return (0); } error = 0; #ifdef DIAGNOSTIC if (VOP_ISLOCKED(vp)) panic("msdosfs_inactive: locked denode"); if (curproc) dep->de_lockholder = curproc->p_pid; else dep->de_lockholder = -1; #endif dep->de_flag |= DE_LOCKED; /* * 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, (u_long)0, 0, NOCRED, NULL); dep->de_Name[0] = SLOT_DELETED; dep->de_flag |= DE_UPDATE; } if (dep->de_flag & DE_UPDATE) deupdat(dep, NULL, 0); VOP_UNLOCK(vp); /* * 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 (vp->v_usecount == 0 && dep->de_Name[0] == SLOT_DELETED) vgone(vp); return (error); }