/* $OpenBSD: msdosfs_lookup.c,v 1.7 1997/10/06 20:20:58 deraadt Exp $ */ /* $NetBSD: msdosfs_lookup.c,v 1.30 1996/10/25 23:14:08 cgd Exp $ */ /*- * Copyright (C) 1994, 1995 Wolfgang Solfrank. * Copyright (C) 1994, 1995 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 #include #include #include #include /* * When we search a directory the blocks containing directory entries are * read and examined. The directory entries contain information that would * normally be in the inode of a unix filesystem. This means that some of * a directory's contents may also be in memory resident denodes (sort of * an inode). This can cause problems if we are searching while some other * process is modifying a directory. To prevent one process from accessing * incompletely modified directory information we depend upon being the * sole owner of a directory block. bread/brelse provide this service. * This being the case, when a process modifies a directory it must first * acquire the disk block that contains the directory entry to be modified. * Then update the disk block and the denode, and then write the disk block * out to disk. This way disk blocks containing directory entries and in * memory denode's will be in synch. */ int msdosfs_lookup(v) void *v; { struct vop_lookup_args /* { struct vnode *a_dvp; struct vnode **a_vpp; struct componentname *a_cnp; } */ *ap = v; struct vnode *vdp = ap->a_dvp; struct vnode **vpp = ap->a_vpp; struct componentname *cnp = ap->a_cnp; daddr_t bn; int error; int lockparent; int wantparent; int slotcount; int slotoffset = 0; int frcn; u_long cluster; int blkoff; int diroff; int blsize; int isadir; /* ~0 if found direntry is a directory */ u_long scn; /* starting cluster number */ struct vnode *pdp; struct denode *dp; struct denode *tdp; struct msdosfsmount *pmp; struct buf *bp = 0; struct direntry *dep; u_char dosfilename[12]; int flags = cnp->cn_flags; int nameiop = cnp->cn_nameiop; int wincnt = 1; int chksum = -1; int olddos = 1; #ifdef MSDOSFS_DEBUG printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr); #endif dp = VTODE(vdp); pmp = dp->de_pmp; *vpp = NULL; lockparent = flags & LOCKPARENT; wantparent = flags & (LOCKPARENT | WANTPARENT); #ifdef MSDOSFS_DEBUG printf("msdosfs_lookup(): vdp %08x, dp %08x, Attr %02x\n", vdp, dp, dp->de_Attributes); #endif /* * Check accessiblity of directory. */ if ((dp->de_Attributes & ATTR_DIRECTORY) == 0) return (ENOTDIR); if ((error = VOP_ACCESS(vdp, VEXEC, cnp->cn_cred, cnp->cn_proc)) != 0) return (error); /* * We now have a segment name to search for, and a directory to search. * * Before tediously performing a linear scan of the directory, * check the name cache to see if the directory/name pair * we are looking for is known already. */ if ((error = cache_lookup(vdp, vpp, cnp)) != 0) { int vpid; if (error == ENOENT) return (error); /* * Get the next vnode in the path. * See comment below starting `Step through' for * an explaination of the locking protocol. */ pdp = vdp; dp = VTODE(*vpp); vdp = *vpp; vpid = vdp->v_id; if (pdp == vdp) { /* lookup on "." */ VREF(vdp); error = 0; } else if (flags & ISDOTDOT) { VOP_UNLOCK(pdp); error = vget(vdp, 1); if (!error && lockparent && (flags & ISLASTCN)) error = VOP_LOCK(pdp); } else { error = vget(vdp, 1); if (!lockparent || error || !(flags & ISLASTCN)) VOP_UNLOCK(pdp); } /* * Check that the capability number did not change * while we were waiting for the lock. */ if (!error) { if (vpid == vdp->v_id) { #ifdef MSDOSFS_DEBUG printf("msdosfs_lookup(): cache hit, vnode %08x, file %s\n", vdp, dp->de_Name); #endif return (0); } vput(vdp); if (lockparent && pdp != vdp && (flags & ISLASTCN)) VOP_UNLOCK(pdp); } if ((error = VOP_LOCK(pdp)) != 0) return (error); vdp = pdp; dp = VTODE(vdp); *vpp = NULL; } /* * If they are going after the . or .. entry in the root directory, * they won't find it. DOS filesystems don't have them in the root * directory. So, we fake it. deget() is in on this scam too. */ if ((vdp->v_flag & VROOT) && cnp->cn_nameptr[0] == '.' && (cnp->cn_namelen == 1 || (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) { isadir = ATTR_DIRECTORY; scn = MSDOSFSROOT; #ifdef MSDOSFS_DEBUG printf("msdosfs_lookup(): looking for . or .. in root directory\n"); #endif cluster = MSDOSFSROOT; blkoff = MSDOSFSROOT_OFS; goto foundroot; } switch (unix2dosfn((u_char *)cnp->cn_nameptr, dosfilename, cnp->cn_namelen, 0)) { case 0: return (EINVAL); case 1: break; case 2: wincnt = winSlotCnt((u_char *)cnp->cn_nameptr, cnp->cn_namelen) + 1; break; case 3: olddos = 0; wincnt = winSlotCnt((u_char *)cnp->cn_nameptr, cnp->cn_namelen) + 1; break; } if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) wincnt = 1; /* * Suppress search for slots unless creating * file and at end of pathname, in which case * we watch for a place to put the new file in * case it doesn't already exist. */ slotcount = wincnt; if ((nameiop == CREATE || nameiop == RENAME) && (flags & ISLASTCN)) slotcount = 0; #ifdef MSDOSFS_DEBUG printf("msdosfs_lookup(): dos version of filename %s, length %d\n", dosfilename, cnp->cn_namelen); #endif /* * Search the directory pointed at by vdp for the name pointed at * by cnp->cn_nameptr. */ tdp = NULL; /* * The outer loop ranges over the clusters that make up the * directory. Note that the root directory is different from all * other directories. It has a fixed number of blocks that are not * part of the pool of allocatable clusters. So, we treat it a * little differently. The root directory starts at "cluster" 0. */ diroff = 0; for (frcn = 0;; frcn++) { if ((error = pcbmap(dp, frcn, &bn, &cluster, &blsize)) != 0) { if (error == E2BIG) break; return (error); } error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); if (error) { brelse(bp); return (error); } for (blkoff = 0; blkoff < blsize; blkoff += sizeof(struct direntry), diroff += sizeof(struct direntry)) { dep = (struct direntry *)(bp->b_data + blkoff); /* * If the slot is empty and we are still looking * for an empty then remember this one. If the * slot is not empty then check to see if it * matches what we are looking for. If the slot * has never been filled with anything, then the * remainder of the directory has never been used, * so there is no point in searching it. */ if (dep->deName[0] == SLOT_EMPTY || dep->deName[0] == SLOT_DELETED) { /* * Drop memory of previous long matches */ chksum = -1; if (slotcount < wincnt) { slotcount++; slotoffset = diroff; } if (dep->deName[0] == SLOT_EMPTY) { brelse(bp); goto notfound; } } else { /* * If there wasn't enough space for our winentries, * forget about the empty space */ if (slotcount < wincnt) slotcount = 0; /* * Check for Win95 long filename entry */ if (dep->deAttributes == ATTR_WIN95) { if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) continue; chksum = winChkName((u_char *)cnp->cn_nameptr, cnp->cn_namelen, (struct winentry *)dep, chksum); continue; } /* * Ignore volume labels (anywhere, not just * the root directory). */ if (dep->deAttributes & ATTR_VOLUME) { chksum = -1; continue; } /* * Check for a checksum or name match */ if (chksum != winChksum(dep->deName) && (!olddos || bcmp(dosfilename, dep->deName, 11))) { chksum = -1; continue; } #ifdef MSDOSFS_DEBUG printf("msdosfs_lookup(): match blkoff %d, diroff %d\n", blkoff, diroff); #endif /* * Remember where this directory * entry came from for whoever did * this lookup. */ dp->de_fndoffset = diroff; dp->de_fndcnt = 0; /* unused anyway */ goto found; } } /* for (blkoff = 0; .... */ /* * Release the buffer holding the directory cluster just * searched. */ brelse(bp); } /* for (frcn = 0; ; frcn++) */ notfound:; /* * We hold no disk buffers at this point. */ /* * Fixup the slot description to point to the place where * we might put the new DOS direntry (putting the Win95 * long name entries before that) */ if (!slotcount) { slotcount = 1; slotoffset = diroff; } if (wincnt > slotcount) slotoffset += sizeof(struct direntry) * (wincnt - slotcount); /* * If we get here we didn't find the entry we were looking for. But * that's ok if we are creating or renaming and are at the end of * the pathname and the directory hasn't been removed. */ #ifdef MSDOSFS_DEBUG printf("msdosfs_lookup(): op %d, refcnt %d\n", nameiop, dp->de_refcnt); printf(" slotcount %d, slotoffset %d\n", slotcount, slotoffset); #endif if ((nameiop == CREATE || nameiop == RENAME) && (flags & ISLASTCN) && dp->de_refcnt != 0) { /* * Access for write is interpreted as allowing * creation of files in the directory. */ error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_proc); if (error) return (error); /* * Return an indication of where the new directory * entry should be put. */ dp->de_fndoffset = slotoffset; dp->de_fndcnt = wincnt - 1; /* * We return with the directory locked, so that * the parameters we set up above will still be * valid if we actually decide to do a direnter(). * We return ni_vp == NULL to indicate that the entry * does not currently exist; we leave a pointer to * the (locked) directory inode in ndp->ni_dvp. * The pathname buffer is saved so that the name * can be obtained later. * * NB - if the directory is unlocked, then this * information cannot be used. */ cnp->cn_flags |= SAVENAME; if (!lockparent) VOP_UNLOCK(vdp); return (EJUSTRETURN); } /* * Insert name into cache (as non-existent) if appropriate. */ if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE) cache_enter(vdp, *vpp, cnp); return (ENOENT); found:; /* * NOTE: We still have the buffer with matched directory entry at * this point. */ isadir = dep->deAttributes & ATTR_DIRECTORY; scn = getushort(dep->deStartCluster); if (cluster == MSDOSFSROOT) blkoff = diroff; if (isadir) { cluster = scn; if (cluster == MSDOSFSROOT) blkoff = MSDOSFSROOT_OFS; else blkoff = 0; } /* * Now release buf to allow deget to read the entry again. * Reserving it here and giving it to deget could result * in a deadlock. */ brelse(bp); foundroot:; /* * If we entered at foundroot, then we are looking for the . or .. * entry of the filesystems root directory. isadir and scn were * setup before jumping here. And, bp is already null. */ /* * If deleting, and at end of pathname, return * parameters which can be used to remove file. * If the wantparent flag isn't set, we return only * the directory (in ndp->ni_dvp), otherwise we go * on and lock the inode, being careful with ".". */ if (nameiop == DELETE && (flags & ISLASTCN)) { /* * Write access to directory required to delete files. */ error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_proc); if (error) return (error); /* * Return pointer to current entry in dp->i_offset. * Save directory inode pointer in ndp->ni_dvp for dirremove(). */ if (dp->de_StartCluster == scn && isadir) { /* "." */ VREF(vdp); *vpp = vdp; return (0); } if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) return (error); *vpp = DETOV(tdp); if (!lockparent) VOP_UNLOCK(vdp); return (0); } /* * If rewriting (RENAME), return the inode and the * information required to rewrite the present directory * Must get inode of directory entry to verify it's a * regular file, or empty directory. */ if (nameiop == RENAME && wantparent && (flags & ISLASTCN)) { error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_proc); if (error) return (error); /* * Careful about locking second inode. * This can only occur if the target is ".". */ if (dp->de_StartCluster == scn && isadir) return (EISDIR); if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) return (error); *vpp = DETOV(tdp); cnp->cn_flags |= SAVENAME; if (!lockparent) VOP_UNLOCK(vdp); return (0); } /* * Step through the translation in the name. We do not `vput' the * directory because we may need it again if a symbolic link * is relative to the current directory. Instead we save it * unlocked as "pdp". We must get the target inode before unlocking * the directory to insure that the inode will not be removed * before we get it. We prevent deadlock by always fetching * inodes from the root, moving down the directory tree. Thus * when following backward pointers ".." we must unlock the * parent directory before getting the requested directory. * There is a potential race condition here if both the current * and parent directories are removed before the VFS_VGET for the * inode associated with ".." returns. We hope that this occurs * infrequently since we cannot avoid this race condition without * implementing a sophisticated deadlock detection algorithm. * Note also that this simple deadlock detection scheme will not * work if the file system has any hard links other than ".." * that point backwards in the directory structure. */ pdp = vdp; if (flags & ISDOTDOT) { VOP_UNLOCK(pdp); /* race to get the inode */ if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) { VOP_LOCK(pdp); return (error); } if (lockparent && (flags & ISLASTCN) && (error = VOP_LOCK(pdp))) { vput(DETOV(tdp)); return (error); } *vpp = DETOV(tdp); } else if (dp->de_StartCluster == scn && isadir) { VREF(vdp); /* we want ourself, ie "." */ *vpp = vdp; } else { if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) return (error); if (!lockparent || !(flags & ISLASTCN)) VOP_UNLOCK(pdp); *vpp = DETOV(tdp); } /* * Insert name into cache if appropriate. */ if (cnp->cn_flags & MAKEENTRY) cache_enter(vdp, *vpp, cnp); return (0); } /* * dep - directory entry to copy into the directory * ddep - directory to add to * depp - return the address of the denode for the created directory entry * if depp != 0 * cnp - componentname needed for Win95 long filenames */ int createde(dep, ddep, depp, cnp) struct denode *dep; struct denode *ddep; struct denode **depp; struct componentname *cnp; { int error; u_long dirclust, diroffset; struct direntry *ndep; struct msdosfsmount *pmp = ddep->de_pmp; struct buf *bp; daddr_t bn; int blsize; #ifdef MSDOSFS_DEBUG printf("createde(dep %08x, ddep %08x, depp %08x, cnp %08x)\n", dep, ddep, depp, cnp); #endif /* * If no space left in the directory then allocate another cluster * and chain it onto the end of the file. There is one exception * to this. That is, if the root directory has no more space it * can NOT be expanded. extendfile() checks for and fails attempts * to extend the root directory. We just return an error in that * case. */ if (ddep->de_fndoffset >= ddep->de_FileSize) { diroffset = ddep->de_fndoffset + sizeof(struct direntry) - ddep->de_FileSize; dirclust = de_clcount(pmp, diroffset); if ((error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR)) != 0) { (void)detrunc(ddep, ddep->de_FileSize, 0, NOCRED, NULL); return error; } /* * Update the size of the directory */ ddep->de_FileSize += de_cn2off(pmp, dirclust); } /* * We just read in the cluster with space. Copy the new directory * entry in. Then write it to disk. NOTE: DOS directories * do not get smaller as clusters are emptied. */ error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset), &bn, &dirclust, &blsize); if (error) return error; diroffset = ddep->de_fndoffset; if (dirclust != MSDOSFSROOT) diroffset &= pmp->pm_crbomask; if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) != 0) { brelse(bp); return error; } ndep = bptoep(pmp, bp, ddep->de_fndoffset); DE_EXTERNALIZE(ndep, dep); /* * Now write the Win95 long name */ if (ddep->de_fndcnt > 0) { u_int8_t chksum = winChksum(ndep->deName); u_char *un = (u_char *)cnp->cn_nameptr; int unlen = cnp->cn_namelen; int cnt = 1; while (--ddep->de_fndcnt >= 0) { if (!(ddep->de_fndoffset & pmp->pm_crbomask)) { if ((error = bwrite(bp)) != 0) return error; ddep->de_fndoffset -= sizeof(struct direntry); error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset), &bn, 0, &blsize); if (error) return error; error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); if (error) { brelse(bp); return error; } ndep = bptoep(pmp, bp, ddep->de_fndoffset); } else { ndep--; ddep->de_fndoffset -= sizeof(struct direntry); } if (!unix2winfn(un, unlen, (struct winentry *)ndep, cnt++, chksum)) break; } } if ((error = bwrite(bp)) != 0) return error; /* * If they want us to return with the denode gotten. */ if (depp) { if (dep->de_Attributes & ATTR_DIRECTORY) { dirclust = dep->de_StartCluster; if (dirclust == MSDOSFSROOT) diroffset = MSDOSFSROOT_OFS; else diroffset = 0; } return deget(pmp, dirclust, diroffset, depp); } return 0; } /* * Be sure a directory is empty except for "." and "..". Return 1 if empty, * return 0 if not empty or error. */ int dosdirempty(dep) struct denode *dep; { int blsize; int error; u_long cn; daddr_t bn; struct buf *bp; struct msdosfsmount *pmp = dep->de_pmp; struct direntry *dentp; /* * Since the filesize field in directory entries for a directory is * zero, we just have to feel our way through the directory until * we hit end of file. */ for (cn = 0;; cn++) { if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { if (error == E2BIG) return (1); /* it's empty */ return (0); } error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); if (error) { brelse(bp); return (0); } for (dentp = (struct direntry *)bp->b_data; (char *)dentp < bp->b_data + blsize; dentp++) { if (dentp->deName[0] != SLOT_DELETED && (dentp->deAttributes & ATTR_VOLUME) == 0) { /* * In dos directories an entry whose name * starts with SLOT_EMPTY (0) starts the * beginning of the unused part of the * directory, so we can just return that it * is empty. */ if (dentp->deName[0] == SLOT_EMPTY) { brelse(bp); return (1); } /* * Any names other than "." and ".." in a * directory mean it is not empty. */ if (bcmp(dentp->deName, ". ", 11) && bcmp(dentp->deName, ".. ", 11)) { brelse(bp); #ifdef MSDOSFS_DEBUG printf("dosdirempty(): entry found %02x, %02x\n", dentp->deName[0], dentp->deName[1]); #endif return (0); /* not empty */ } } } brelse(bp); } /* NOTREACHED */ } /* * Check to see if the directory described by target is in some * subdirectory of source. This prevents something like the following from * succeeding and leaving a bunch or files and directories orphaned. mv * /a/b/c /a/b/c/d/e/f Where c and f are directories. * * source - the inode for /a/b/c * target - the inode for /a/b/c/d/e/f * * Returns 0 if target is NOT a subdirectory of source. * Otherwise returns a non-zero error number. * The target inode is always unlocked on return. */ int doscheckpath(source, target) struct denode *source; struct denode *target; { daddr_t scn; struct msdosfsmount *pmp; struct direntry *ep; struct denode *dep; struct buf *bp = NULL; int error = 0; dep = target; if ((target->de_Attributes & ATTR_DIRECTORY) == 0 || (source->de_Attributes & ATTR_DIRECTORY) == 0) { error = ENOTDIR; goto out; } if (dep->de_StartCluster == source->de_StartCluster) { error = EEXIST; goto out; } if (dep->de_StartCluster == MSDOSFSROOT) goto out; for (;;) { if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) { error = ENOTDIR; break; } pmp = dep->de_pmp; scn = dep->de_StartCluster; error = bread(pmp->pm_devvp, cntobn(pmp, scn), pmp->pm_bpcluster, NOCRED, &bp); if (error) break; ep = (struct direntry *) bp->b_data + 1; if ((ep->deAttributes & ATTR_DIRECTORY) == 0 || bcmp(ep->deName, ".. ", 11) != 0) { error = ENOTDIR; break; } scn = getushort(ep->deStartCluster); if (scn == source->de_StartCluster) { error = EINVAL; break; } if (scn == MSDOSFSROOT) break; vput(DETOV(dep)); brelse(bp); bp = NULL; /* NOTE: deget() clears dep on error */ if ((error = deget(pmp, scn, 0, &dep)) != 0) break; } out:; if (bp) brelse(bp); if (error == ENOTDIR) printf("doscheckpath(): .. not a directory?\n"); if (dep != NULL) vput(DETOV(dep)); return (error); } /* * Read in the disk block containing the directory entry (dirclu, dirofs) * and return the address of the buf header, and the address of the * directory entry within the block. */ int readep(pmp, dirclust, diroffset, bpp, epp) struct msdosfsmount *pmp; u_long dirclust, diroffset; struct buf **bpp; struct direntry **epp; { int error; daddr_t bn; int blsize; u_long boff; boff = diroffset & ~pmp->pm_crbomask; blsize = pmp->pm_bpcluster; if (dirclust == MSDOSFSROOT && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize) blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask; bn = detobn(pmp, dirclust, diroffset); if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, bpp)) != 0) { brelse(*bpp); *bpp = NULL; return (error); } if (epp) *epp = bptoep(pmp, *bpp, diroffset); return (0); } /* * Read in the disk block containing the directory entry dep came from and * return the address of the buf header, and the address of the directory * entry within the block. */ int readde(dep, bpp, epp) struct denode *dep; struct buf **bpp; struct direntry **epp; { return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset, bpp, epp)); } /* * Remove a directory entry. At this point the file represented by the * directory entry to be removed is still full length until no one has it * open. When the file no longer being used msdosfs_inactive() is called * and will truncate the file to 0 length. When the vnode containing the * denode is needed for some other purpose by VFS it will call * msdosfs_reclaim() which will remove the denode from the denode cache. */ int removede(pdep, dep) struct denode *pdep; /* directory where the entry is removed */ struct denode *dep; /* file to be removed */ { int error; struct direntry *ep; struct buf *bp; daddr_t bn; int blsize; struct msdosfsmount *pmp = pdep->de_pmp; u_long offset = pdep->de_fndoffset; #ifdef MSDOSFS_DEBUG printf("removede(): filename %s, dep %08x, offset %08x\n", dep->de_Name, dep, offset); #endif dep->de_refcnt--; do { error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize); if (error) return error; error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); if (error) { brelse(bp); return error; } ep = bptoep(pmp, bp, offset); while (1) { /* * We are a bit agressive here in that we delete any Win95 * entries preceding this entry, not just the ones we "own". * Since these presumably aren't valid anyway, * there should be no harm. */ ep--->deName[0] = SLOT_DELETED; offset -= sizeof(struct direntry); if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) || !((offset + sizeof(struct direntry)) & pmp->pm_crbomask) || ep->deAttributes != ATTR_WIN95) break; } if ((error = bwrite(bp)) != 0) return error; } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95) && offset && !(offset & pmp->pm_crbomask)); return 0; } /* * Create a unique DOS name in dvp */ int uniqdosname(dep, cnp, cp) struct denode *dep; struct componentname *cnp; u_char *cp; { struct msdosfsmount *pmp = dep->de_pmp; struct direntry *dentp; int gen; int blsize; u_long cn; daddr_t bn; struct buf *bp; int error; for (gen = 1;; gen++) { /* * Generate DOS name with generation number */ if (!unix2dosfn((u_char *)cnp->cn_nameptr, cp, cnp->cn_namelen, gen)) return gen == 1 ? EINVAL : EEXIST; /* * Now look for a dir entry with this exact name */ for (cn = error = 0; !error; cn++) { if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { if (error == E2BIG) /* EOF reached and not found */ return 0; return error; } error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); if (error) { brelse(bp); return error; } for (dentp = (struct direntry *)bp->b_data; (char *)dentp < bp->b_data + blsize; dentp++) { if (dentp->deName[0] == SLOT_EMPTY) { /* * Last used entry and not found */ brelse(bp); return 0; } /* * Ignore volume labels and Win95 entries */ if (dentp->deAttributes & ATTR_VOLUME) continue; if (!bcmp(dentp->deName, cp, 11)) { error = EEXIST; break; } } brelse(bp); } } } /* * Find any Win'95 long filename entry in directory dep */ int findwin95(dep) struct denode *dep; { struct msdosfsmount *pmp = dep->de_pmp; struct direntry *dentp; int blsize; u_long cn; daddr_t bn; struct buf *bp; /* * Read through the directory looking for Win'95 entries * Note: Error currently handled just as EOF XXX */ for (cn = 0;; cn++) { if (pcbmap(dep, cn, &bn, 0, &blsize)) return 0; if (bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) { brelse(bp); return 0; } for (dentp = (struct direntry *)bp->b_data; (char *)dentp < bp->b_data + blsize; dentp++) { if (dentp->deName[0] == SLOT_EMPTY) { /* * Last used entry and not found */ brelse(bp); return 0; } if (dentp->deName[0] == SLOT_DELETED) { /* * Ignore deleted files * Note: might be an indication of Win'95 anyway XXX */ continue; } if (dentp->deAttributes == ATTR_WIN95) { brelse(bp); return 1; } } brelse(bp); } }