/* $OpenBSD: msdosfs_denode.c,v 1.63 2018/05/27 06:02:14 visa 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 #include #include #include #include #include #include #include /* defines "time" */ #include #include #include #include #include #include #include #include u_int msdosfs_dehash(dev_t, uint32_t, uint32_t); struct denode **dehashtbl; SIPHASH_KEY dehashkey; u_long dehash; /* size of hash table - 1 */ #define DEHASH(dev, dcl, doff) msdosfs_dehash((dev), (dcl), (doff)) 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(struct vfsconf *vfsp) { dehashtbl = hashinit(initialvnodes / 2, M_MSDOSFSMNT, M_WAITOK, &dehash); arc4random_buf(&dehashkey, sizeof(dehashkey)); return (0); } u_int msdosfs_dehash(dev_t dev, uint32_t dirclust, uint32_t diroff) { SIPHASH_CTX ctx; SipHash24_Init(&ctx, &dehashkey); SipHash24_Update(&ctx, &dev, sizeof(dev)); SipHash24_Update(&ctx, &dirclust, sizeof(dirclust)); SipHash24_Update(&ctx, &diroff, sizeof(diroff)); return (SipHash24_End(&ctx) & dehash); } static struct denode * msdosfs_hashget(dev_t dev, uint32_t dirclust, uint32_t 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) { struct vnode *vp = DETOV(dep); if (!vget(vp, LK_EXCLUSIVE)) return (dep); break; } } /* NOTREACHED */ } static int msdosfs_hashins(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(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(struct msdosfsmount *pmp, uint32_t dirclust, uint32_t diroffset, struct denode **depp) { int error; extern struct vops msdosfs_vops; struct direntry *direntptr; struct denode *ldep; struct vnode *nvp; struct buf *bp; #ifdef MSDOSFS_DEBUG printf("deget(pmp %p, dirclust %d, diroffset %x, 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. */ 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_vops, &nvp); if (error) { *depp = 0; return (error); } ldep = malloc(sizeof(*ldep), M_MSDOSFSNODE, M_WAITOK | M_ZERO); rrw_init_flags(&ldep->de_lock, "denode", RWL_DUPOK | RWL_IS_VNODE); 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); 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, CLUST_END, 0, &size, 0); if (error == E2BIG) { ldep->de_FileSize = de_cn2off(pmp, size); error = 0; } else if (error) { printf("deget(): pcbmap returned %d\n", error); return (error); } } } else nvp->v_type = VREG; vref(ldep->de_devvp); *depp = ldep; return (0); } int deupdat(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(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 = 0; 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 %.11s, length %u, 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 %u, offset %u\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, &bp); } else { bn = de_blk(pmp, length); error = bread(DETOV(dep), bn, pmp->pm_bpcluster, &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(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(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(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 %p, file %.11s, refcnt %ld\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, 0); vp->v_data = NULL; return (0); } int msdosfs_inactive(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 %p, 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 %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, (uint32_t)0, 0, NOCRED, NULL); dep->de_Name[0] = SLOT_DELETED; } deupdat(dep, 0); out: 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 (dep->de_Name[0] == SLOT_DELETED) vrecycle(vp, p); return (error); }