ext2_lookup.c revision 125843
1118611Snjl/* 2118611Snjl * modified for Lites 1.1 3118611Snjl * 4118611Snjl * Aug 1995, Godmar Back (gback@cs.utah.edu) 5118611Snjl * University of Utah, Department of Computer Science 6118611Snjl */ 7118611Snjl/* 8118611Snjl * Copyright (c) 1989, 1993 9118611Snjl * The Regents of the University of California. All rights reserved. 10118611Snjl * (c) UNIX System Laboratories, Inc. 11118611Snjl * All or some portions of this file are derived from material licensed 12202771Sjkim * to the University of California by American Telephone and Telegraph 13118611Snjl * Co. or Unix System Laboratories, Inc. and are reproduced herein with 14118611Snjl * the permission of UNIX System Laboratories, Inc. 15118611Snjl * 16118611Snjl * Redistribution and use in source and binary forms, with or without 17118611Snjl * modification, are permitted provided that the following conditions 18118611Snjl * are met: 19118611Snjl * 1. Redistributions of source code must retain the above copyright 20118611Snjl * notice, this list of conditions and the following disclaimer. 21118611Snjl * 2. Redistributions in binary form must reproduce the above copyright 22118611Snjl * notice, this list of conditions and the following disclaimer in the 23118611Snjl * documentation and/or other materials provided with the distribution. 24118611Snjl * 3. All advertising materials mentioning features or use of this software 25118611Snjl * must display the following acknowledgement: 26118611Snjl * This product includes software developed by the University of 27118611Snjl * California, Berkeley and its contributors. 28118611Snjl * 4. Neither the name of the University nor the names of its contributors 29118611Snjl * may be used to endorse or promote products derived from this software 30118611Snjl * without specific prior written permission. 31118611Snjl * 32118611Snjl * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 33118611Snjl * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34118611Snjl * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35118611Snjl * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 36118611Snjl * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37118611Snjl * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38118611Snjl * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39118611Snjl * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40118611Snjl * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41118611Snjl * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42118611Snjl * SUCH DAMAGE. 43118611Snjl * 44118611Snjl * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94 45118611Snjl * $FreeBSD: head/sys/gnu/fs/ext2fs/ext2_lookup.c 125843 2004-02-15 08:19:42Z bde $ 46118611Snjl */ 47118611Snjl 48118611Snjl#include <sys/param.h> 49118611Snjl#include <sys/systm.h> 50118611Snjl#include <sys/namei.h> 51118611Snjl#include <sys/bio.h> 52118611Snjl#include <sys/buf.h> 53118611Snjl#include <sys/mount.h> 54118611Snjl#include <sys/vnode.h> 55118611Snjl#include <sys/malloc.h> 56118611Snjl#include <sys/dirent.h> 57118611Snjl#include <sys/sysctl.h> 58118611Snjl 59118611Snjl#include <ufs/ufs/dir.h> 60118611Snjl 61118611Snjl#include <gnu/ext2fs/inode.h> 62118611Snjl#include <gnu/ext2fs/ext2_mount.h> 63118611Snjl#include <gnu/ext2fs/ext2_extern.h> 64118611Snjl#include <gnu/ext2fs/ext2_fs.h> 65118611Snjl#include <gnu/ext2fs/ext2_fs_sb.h> 66118611Snjl 67118611Snjl#ifdef DIAGNOSTIC 68118611Snjlstatic int dirchk = 1; 69118611Snjl#else 70118611Snjlstatic int dirchk = 0; 71118611Snjl#endif 72118611Snjl 73118611SnjlSYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD, 0, "EXT2FS filesystem"); 74118611SnjlSYSCTL_INT(_vfs_e2fs, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, ""); 75118611Snjl 76118611Snjl/* 77118611Snjl DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512) 78118611Snjl while it is the native blocksize in ext2fs - thus, a #define 79118611Snjl is no longer appropriate 80118611Snjl*/ 81118611Snjl#undef DIRBLKSIZ 82118611Snjl 83118611Snjlstatic u_char ext2_ft_to_dt[] = { 84118611Snjl DT_UNKNOWN, /* EXT2_FT_UNKNOWN */ 85118611Snjl DT_REG, /* EXT2_FT_REG_FILE */ 86118611Snjl DT_DIR, /* EXT2_FT_DIR */ 87118611Snjl DT_CHR, /* EXT2_FT_CHRDEV */ 88118611Snjl DT_BLK, /* EXT2_FT_BLKDEV */ 89118611Snjl DT_FIFO, /* EXT2_FT_FIFO */ 90118611Snjl DT_SOCK, /* EXT2_FT_SOCK */ 91118611Snjl DT_LNK, /* EXT2_FT_SYMLINK */ 92118611Snjl}; 93118611Snjl#define FTTODT(ft) \ 94118611Snjl ((ft) > sizeof(ext2_ft_to_dt) / sizeof(ext2_ft_to_dt[0]) ? \ 95118611Snjl DT_UNKNOWN : ext2_ft_to_dt[(ft)]) 96118611Snjl 97118611Snjlstatic u_char dt_to_ext2_ft[] = { 98118611Snjl EXT2_FT_UNKNOWN, /* DT_UNKNOWN */ 99118611Snjl EXT2_FT_FIFO, /* DT_FIFO */ 100118611Snjl EXT2_FT_CHRDEV, /* DT_CHR */ 101118611Snjl EXT2_FT_UNKNOWN, /* unused */ 102118611Snjl EXT2_FT_DIR, /* DT_DIR */ 103118611Snjl EXT2_FT_UNKNOWN, /* unused */ 104118611Snjl EXT2_FT_BLKDEV, /* DT_BLK */ 105118611Snjl EXT2_FT_UNKNOWN, /* unused */ 106118611Snjl EXT2_FT_REG_FILE, /* DT_REG */ 107118611Snjl EXT2_FT_UNKNOWN, /* unused */ 108118611Snjl EXT2_FT_SYMLINK, /* DT_LNK */ 109118611Snjl EXT2_FT_UNKNOWN, /* unused */ 110118611Snjl EXT2_FT_SOCK, /* DT_SOCK */ 111118611Snjl EXT2_FT_UNKNOWN, /* unused */ 112118611Snjl EXT2_FT_UNKNOWN, /* DT_WHT */ 113118611Snjl}; 114118611Snjl#define DTTOFT(dt) \ 115118611Snjl ((dt) > sizeof(dt_to_ext2_ft) / sizeof(dt_to_ext2_ft[0]) ? \ 116118611Snjl EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)]) 117118611Snjl 118151937Sjkimstatic int ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de, 119118611Snjl int entryoffsetinblock); 120118611Snjl 121118611Snjl/* 122118611Snjl * Vnode op for reading directories. 123151937Sjkim * 124118611Snjl * The routine below assumes that the on-disk format of a directory 125151937Sjkim * is the same as that defined by <sys/dirent.h>. If the on-disk 126151937Sjkim * format changes, then it will be necessary to do a conversion 127151937Sjkim * from the on-disk format that read returns to the format defined 128151937Sjkim * by <sys/dirent.h>. 129151937Sjkim */ 130193529Sjkim/* 131193529Sjkim * this is exactly what we do here - the problem is that the conversion 132193529Sjkim * will blow up some entries by four bytes, so it can't be done in place. 133193529Sjkim * This is too bad. Right now the conversion is done entry by entry, the 134193529Sjkim * converted entry is sent via uiomove. 135193529Sjkim * 136193529Sjkim * XXX allocate a buffer, convert as many entries as possible, then send 137193529Sjkim * the whole buffer to uiomove 138193529Sjkim */ 139193529Sjkimint 140193529Sjkimext2_readdir(ap) 141193529Sjkim struct vop_readdir_args /* { 142193529Sjkim struct vnode *a_vp; 143193529Sjkim struct uio *a_uio; 144193529Sjkim struct ucred *a_cred; 145193529Sjkim } */ *ap; 146193529Sjkim{ 147193529Sjkim struct uio *uio = ap->a_uio; 148193529Sjkim int count, error; 149193529Sjkim 150118611Snjl struct ext2_dir_entry_2 *edp, *dp; 151118611Snjl int ncookies; 152118611Snjl struct dirent dstdp; 153118611Snjl struct uio auio; 154118611Snjl struct iovec aiov; 155118611Snjl caddr_t dirbuf; 156118611Snjl int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize; 157118611Snjl int readcnt; 158118611Snjl off_t startoffset = uio->uio_offset; 159118611Snjl 160118611Snjl count = uio->uio_resid; 161118611Snjl /* 162118611Snjl * Avoid complications for partial directory entries by adjusting 163118611Snjl * the i/o to end at a block boundary. Don't give up (like ufs 164151937Sjkim * does) if the initial adjustment gives a negative count, since 165118611Snjl * many callers don't supply a large enough buffer. The correct 166118611Snjl * size is a little larger than DIRBLKSIZ to allow for expansion 167118611Snjl * of directory entries, but some callers just use 512. 168118611Snjl */ 169118611Snjl count -= (uio->uio_offset + count) & (DIRBLKSIZ -1); 170118611Snjl if (count <= 0) 171118611Snjl count += DIRBLKSIZ; 172202771Sjkim 173118611Snjl#ifdef EXT2FS_DEBUG 174118611Snjl printf("ext2_readdir: uio_offset = %lld, uio_resid = %d, count = %d\n", 175118611Snjl uio->uio_offset, uio->uio_resid, count); 176118611Snjl#endif 177118611Snjl 178118611Snjl auio = *uio; 179118611Snjl auio.uio_iov = &aiov; 180202771Sjkim auio.uio_iovcnt = 1; 181202771Sjkim auio.uio_resid = count; 182202771Sjkim auio.uio_segflg = UIO_SYSSPACE; 183202771Sjkim aiov.iov_len = count; 184118611Snjl MALLOC(dirbuf, caddr_t, count, M_TEMP, M_WAITOK); 185118611Snjl aiov.iov_base = dirbuf; 186118611Snjl error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred); 187118611Snjl if (error == 0) { 188118611Snjl readcnt = count - auio.uio_resid; 189118611Snjl edp = (struct ext2_dir_entry_2 *)&dirbuf[readcnt]; 190118611Snjl ncookies = 0; 191118611Snjl bzero(&dstdp, offsetof(struct dirent, d_name)); 192118611Snjl for (dp = (struct ext2_dir_entry_2 *)dirbuf; 193118611Snjl !error && uio->uio_resid > 0 && dp < edp; ) { 194118611Snjl /*- 195118611Snjl * "New" ext2fs directory entries differ in 3 ways 196118611Snjl * from ufs on-disk ones: 197118611Snjl * - the name is not necessarily NUL-terminated. 198118611Snjl * - the file type field always exists and always 199118611Snjl * follows the name length field. 200118611Snjl * - the file type is encoded in a different way. 201118611Snjl * 202118611Snjl * "Old" ext2fs directory entries need no special 203118611Snjl * conversions, since they are binary compatible 204118611Snjl * with "new" entries having a file type of 0 (i.e., 205118611Snjl * EXT2_FT_UNKNOWN). Splitting the old name length 206118611Snjl * field didn't make a mess like it did in ufs, 207118611Snjl * because ext2fs uses a machine-independent disk 208118611Snjl * layout. 209118611Snjl */ 210118611Snjl dstdp.d_fileno = dp->inode; 211118611Snjl dstdp.d_type = FTTODT(dp->file_type); 212118611Snjl dstdp.d_namlen = dp->name_len; 213151937Sjkim dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp); 214118611Snjl bcopy(dp->name, dstdp.d_name, dstdp.d_namlen); 215118611Snjl bzero(dstdp.d_name + dstdp.d_namlen, 216118611Snjl dstdp.d_reclen - offsetof(struct dirent, d_name) - 217118611Snjl dstdp.d_namlen); 218118611Snjl 219118611Snjl if (dp->rec_len > 0) { 220118611Snjl if(dstdp.d_reclen <= uio->uio_resid) { 221118611Snjl /* advance dp */ 222118611Snjl dp = (struct ext2_dir_entry_2 *) 223118611Snjl ((char *)dp + dp->rec_len); 224118611Snjl error = 225118611Snjl uiomove(&dstdp, dstdp.d_reclen, uio); 226118611Snjl if (!error) 227118611Snjl ncookies++; 228118611Snjl } else 229118611Snjl break; 230118611Snjl } else { 231118611Snjl error = EIO; 232118611Snjl break; 233118611Snjl } 234118611Snjl } 235151937Sjkim /* we need to correct uio_offset */ 236151937Sjkim uio->uio_offset = startoffset + (caddr_t)dp - dirbuf; 237118611Snjl 238118611Snjl if (!error && ap->a_ncookies != NULL) { 239118611Snjl u_long *cookiep, *cookies, *ecookies; 240118611Snjl off_t off; 241118611Snjl 242118611Snjl if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) 243118611Snjl panic("ext2_readdir: unexpected uio from NFS server"); 244118611Snjl MALLOC(cookies, u_long *, ncookies * sizeof(u_long), M_TEMP, 245118611Snjl M_WAITOK); 246193529Sjkim off = startoffset; 247193529Sjkim for (dp = (struct ext2_dir_entry_2 *)dirbuf, 248193529Sjkim cookiep = cookies, ecookies = cookies + ncookies; 249193529Sjkim cookiep < ecookies; 250193529Sjkim dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) { 251151937Sjkim off += dp->rec_len; 252151937Sjkim *cookiep++ = (u_long) off; 253151937Sjkim } 254151937Sjkim *ap->a_ncookies = ncookies; 255118611Snjl *ap->a_cookies = cookies; 256118611Snjl } 257118611Snjl } 258118611Snjl FREE(dirbuf, M_TEMP); 259118611Snjl if (ap->a_eofflag) 260118611Snjl *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset; 261118611Snjl return (error); 262118611Snjl} 263118611Snjl 264118611Snjl/* 265118611Snjl * Convert a component of a pathname into a pointer to a locked inode. 266118611Snjl * This is a very central and rather complicated routine. 267118611Snjl * If the file system is not maintained in a strict tree hierarchy, 268118611Snjl * this can result in a deadlock situation (see comments in code below). 269118611Snjl * 270118611Snjl * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending 271118611Snjl * on whether the name is to be looked up, created, renamed, or deleted. 272118611Snjl * When CREATE, RENAME, or DELETE is specified, information usable in 273118611Snjl * creating, renaming, or deleting a directory entry may be calculated. 274118611Snjl * If flag has LOCKPARENT or'ed into it and the target of the pathname 275118611Snjl * exists, lookup returns both the target and its parent directory locked. 276118611Snjl * When creating or renaming and LOCKPARENT is specified, the target may 277118611Snjl * not be ".". When deleting and LOCKPARENT is specified, the target may 278118611Snjl * be "."., but the caller must check to ensure it does an vrele and vput 279118611Snjl * instead of two vputs. 280118611Snjl * 281118611Snjl * Overall outline of ext2_lookup: 282118611Snjl * 283118611Snjl * search for name in directory, to found or notfound 284118611Snjl * notfound: 285118611Snjl * if creating, return locked directory, leaving info on available slots 286118611Snjl * else return error 287118611Snjl * found: 288118611Snjl * if at end of path and deleting, return information to allow delete 289118611Snjl * if at end of path and rewriting (RENAME and LOCKPARENT), lock target 290118611Snjl * inode and return info to allow rewrite 291118611Snjl * if not at end, add name to cache; if at end and neither creating 292118611Snjl * nor deleting, add name to cache 293118611Snjl */ 294118611Snjlint 295118611Snjlext2_lookup(ap) 296118611Snjl struct vop_cachedlookup_args /* { 297118611Snjl struct vnode *a_dvp; 298118611Snjl struct vnode **a_vpp; 299118611Snjl struct componentname *a_cnp; 300118611Snjl } */ *ap; 301118611Snjl{ 302118611Snjl struct vnode *vdp; /* vnode for directory being searched */ 303118611Snjl struct inode *dp; /* inode for directory being searched */ 304118611Snjl struct buf *bp; /* a buffer of directory entries */ 305118611Snjl struct ext2_dir_entry_2 *ep; /* the current directory entry */ 306151937Sjkim int entryoffsetinblock; /* offset of ep in bp's buffer */ 307151937Sjkim enum {NONE, COMPACT, FOUND} slotstatus; 308118611Snjl doff_t slotoffset; /* offset of area with free space */ 309118611Snjl int slotsize; /* size of area at slotoffset */ 310151937Sjkim int slotfreespace; /* amount of space free in slot */ 311193529Sjkim int slotneeded; /* size of the entry we're seeking */ 312193529Sjkim int numdirpasses; /* strategy for directory search */ 313118611Snjl doff_t endsearch; /* offset to end directory search */ 314118611Snjl doff_t prevoff; /* prev entry dp->i_offset */ 315118611Snjl struct vnode *pdp; /* saved dp during symlink work */ 316151937Sjkim struct vnode *tdp; /* returned by VFS_VGET */ 317151937Sjkim doff_t enduseful; /* pointer past last used dir slot */ 318118611Snjl u_long bmask; /* block offset mask */ 319151937Sjkim int lockparent; /* 1 => lockparent flag is set */ 320193529Sjkim int wantparent; /* 1 => wantparent or lockparent flag */ 321193529Sjkim int namlen, error; 322118611Snjl struct vnode **vpp = ap->a_vpp; 323118611Snjl struct componentname *cnp = ap->a_cnp; 324151937Sjkim struct ucred *cred = cnp->cn_cred; 325118611Snjl int flags = cnp->cn_flags; 326118611Snjl int nameiop = cnp->cn_nameiop; 327151937Sjkim struct thread *td = cnp->cn_thread; 328118611Snjl 329118611Snjl int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize; 330118611Snjl 331118611Snjl bp = NULL; 332118611Snjl slotoffset = -1; 333118611Snjl *vpp = NULL; 334118611Snjl vdp = ap->a_dvp; 335118611Snjl dp = VTOI(vdp); 336118611Snjl lockparent = flags & LOCKPARENT; 337118611Snjl wantparent = flags & (LOCKPARENT|WANTPARENT); 338118611Snjl 339118611Snjl /* 340118611Snjl * We now have a segment name to search for, and a directory to search. 341118611Snjl */ 342118611Snjl 343118611Snjl /* 344118611Snjl * Suppress search for slots unless creating 345118611Snjl * file and at end of pathname, in which case 346118611Snjl * we watch for a place to put the new file in 347118611Snjl * case it doesn't already exist. 348118611Snjl */ 349118611Snjl slotstatus = FOUND; 350118611Snjl slotfreespace = slotsize = slotneeded = 0; 351118611Snjl if ((nameiop == CREATE || nameiop == RENAME) && 352118611Snjl (flags & ISLASTCN)) { 353118611Snjl slotstatus = NONE; 354118611Snjl slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen); 355118611Snjl /* was 356118611Snjl slotneeded = (sizeof(struct direct) - MAXNAMLEN + 357118611Snjl cnp->cn_namelen + 3) &~ 3; */ 358118611Snjl } 359118611Snjl 360118611Snjl /* 361118611Snjl * If there is cached information on a previous search of 362118611Snjl * this directory, pick up where we last left off. 363118611Snjl * We cache only lookups as these are the most common 364118611Snjl * and have the greatest payoff. Caching CREATE has little 365118611Snjl * benefit as it usually must search the entire directory 366118611Snjl * to determine that the entry does not exist. Caching the 367118611Snjl * location of the last DELETE or RENAME has not reduced 368118611Snjl * profiling time and hence has been removed in the interest 369118611Snjl * of simplicity. 370118611Snjl */ 371118611Snjl bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; 372118611Snjl if (nameiop != LOOKUP || dp->i_diroff == 0 || 373118611Snjl dp->i_diroff > dp->i_size) { 374118611Snjl entryoffsetinblock = 0; 375118611Snjl dp->i_offset = 0; 376118611Snjl numdirpasses = 1; 377118611Snjl } else { 378118611Snjl dp->i_offset = dp->i_diroff; 379118611Snjl if ((entryoffsetinblock = dp->i_offset & bmask) && 380118611Snjl (error = ext2_blkatoff(vdp, (off_t)dp->i_offset, NULL, 381118611Snjl &bp))) 382118611Snjl return (error); 383118611Snjl numdirpasses = 2; 384118611Snjl nchstats.ncs_2passes++; 385118611Snjl } 386118611Snjl prevoff = dp->i_offset; 387118611Snjl endsearch = roundup(dp->i_size, DIRBLKSIZ); 388118611Snjl enduseful = 0; 389118611Snjl 390118611Snjlsearchloop: 391118611Snjl while (dp->i_offset < endsearch) { 392118611Snjl /* 393118611Snjl * If necessary, get the next directory block. 394118611Snjl */ 395118611Snjl if ((dp->i_offset & bmask) == 0) { 396118611Snjl if (bp != NULL) 397118611Snjl brelse(bp); 398118611Snjl if ((error = 399118611Snjl ext2_blkatoff(vdp, (off_t)dp->i_offset, NULL, 400118611Snjl &bp)) != 0) 401118611Snjl return (error); 402118611Snjl entryoffsetinblock = 0; 403118611Snjl } 404118611Snjl /* 405118611Snjl * If still looking for a slot, and at a DIRBLKSIZE 406118611Snjl * boundary, have to start looking for free space again. 407118611Snjl */ 408118611Snjl if (slotstatus == NONE && 409118611Snjl (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) { 410151937Sjkim slotoffset = -1; 411118611Snjl slotfreespace = 0; 412118611Snjl } 413118611Snjl /* 414118611Snjl * Get pointer to next entry. 415118611Snjl * Full validation checks are slow, so we only check 416118611Snjl * enough to insure forward progress through the 417118611Snjl * directory. Complete checks can be run by setting 418118611Snjl * "vfs.e2fs.dirchk" to be true. 419118611Snjl */ 420118611Snjl ep = (struct ext2_dir_entry_2 *) 421118611Snjl ((char *)bp->b_data + entryoffsetinblock); 422118611Snjl if (ep->rec_len == 0 || 423118611Snjl (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) { 424118611Snjl int i; 425118611Snjl ext2_dirbad(dp, dp->i_offset, "mangled entry"); 426118611Snjl i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); 427118611Snjl dp->i_offset += i; 428118611Snjl entryoffsetinblock += i; 429118611Snjl continue; 430118611Snjl } 431118611Snjl 432118611Snjl /* 433118611Snjl * If an appropriate sized slot has not yet been found, 434118611Snjl * check to see if one is available. Also accumulate space 435118611Snjl * in the current block so that we can determine if 436118611Snjl * compaction is viable. 437118611Snjl */ 438118611Snjl if (slotstatus != FOUND) { 439118611Snjl int size = ep->rec_len; 440118611Snjl 441118611Snjl if (ep->inode != 0) 442118611Snjl size -= EXT2_DIR_REC_LEN(ep->name_len); 443118611Snjl if (size > 0) { 444118611Snjl if (size >= slotneeded) { 445118611Snjl slotstatus = FOUND; 446118611Snjl slotoffset = dp->i_offset; 447118611Snjl slotsize = ep->rec_len; 448118611Snjl } else if (slotstatus == NONE) { 449118611Snjl slotfreespace += size; 450118611Snjl if (slotoffset == -1) 451118611Snjl slotoffset = dp->i_offset; 452118611Snjl if (slotfreespace >= slotneeded) { 453118611Snjl slotstatus = COMPACT; 454118611Snjl slotsize = dp->i_offset + 455118611Snjl ep->rec_len - slotoffset; 456118611Snjl } 457118611Snjl } 458151937Sjkim } 459118611Snjl } 460118611Snjl 461118611Snjl /* 462118611Snjl * Check for a name match. 463118611Snjl */ 464118611Snjl if (ep->inode) { 465118611Snjl namlen = ep->name_len; 466118611Snjl if (namlen == cnp->cn_namelen && 467118611Snjl !bcmp(cnp->cn_nameptr, ep->name, 468118611Snjl (unsigned)namlen)) { 469118611Snjl /* 470118611Snjl * Save directory entry's inode number and 471118611Snjl * reclen in ndp->ni_ufs area, and release 472118611Snjl * directory buffer. 473118611Snjl */ 474118611Snjl dp->i_ino = ep->inode; 475118611Snjl dp->i_reclen = ep->rec_len; 476118611Snjl goto found; 477118611Snjl } 478118611Snjl } 479118611Snjl prevoff = dp->i_offset; 480118611Snjl dp->i_offset += ep->rec_len; 481118611Snjl entryoffsetinblock += ep->rec_len; 482118611Snjl if (ep->inode) 483118611Snjl enduseful = dp->i_offset; 484118611Snjl } 485118611Snjl/* notfound: */ 486118611Snjl /* 487118611Snjl * If we started in the middle of the directory and failed 488118611Snjl * to find our target, we must check the beginning as well. 489118611Snjl */ 490118611Snjl if (numdirpasses == 2) { 491118611Snjl numdirpasses--; 492118611Snjl dp->i_offset = 0; 493118611Snjl endsearch = dp->i_diroff; 494118611Snjl goto searchloop; 495118611Snjl } 496118611Snjl if (bp != NULL) 497118611Snjl brelse(bp); 498118611Snjl /* 499118611Snjl * If creating, and at end of pathname and current 500118611Snjl * directory has not been removed, then can consider 501118611Snjl * allowing file to be created. 502118611Snjl */ 503118611Snjl if ((nameiop == CREATE || nameiop == RENAME) && 504118611Snjl (flags & ISLASTCN) && dp->i_nlink != 0) { 505118611Snjl /* 506118611Snjl * Access for write is interpreted as allowing 507118611Snjl * creation of files in the directory. 508118611Snjl */ 509118611Snjl if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 510118611Snjl return (error); 511118611Snjl /* 512118611Snjl * Return an indication of where the new directory 513118611Snjl * entry should be put. If we didn't find a slot, 514118611Snjl * then set dp->i_count to 0 indicating 515118611Snjl * that the new slot belongs at the end of the 516118611Snjl * directory. If we found a slot, then the new entry 517118611Snjl * can be put in the range from dp->i_offset to 518118611Snjl * dp->i_offset + dp->i_count. 519118611Snjl */ 520118611Snjl if (slotstatus == NONE) { 521118611Snjl dp->i_offset = roundup(dp->i_size, DIRBLKSIZ); 522118611Snjl dp->i_count = 0; 523118611Snjl enduseful = dp->i_offset; 524118611Snjl } else { 525118611Snjl dp->i_offset = slotoffset; 526118611Snjl dp->i_count = slotsize; 527118611Snjl if (enduseful < slotoffset + slotsize) 528167802Sjkim enduseful = slotoffset + slotsize; 529118611Snjl } 530118611Snjl dp->i_endoff = roundup(enduseful, DIRBLKSIZ); 531118611Snjl dp->i_flag |= IN_CHANGE | IN_UPDATE; 532118611Snjl /* 533118611Snjl * We return with the directory locked, so that 534199337Sjkim * the parameters we set up above will still be 535118611Snjl * valid if we actually decide to do a direnter(). 536118611Snjl * We return ni_vp == NULL to indicate that the entry 537118611Snjl * does not currently exist; we leave a pointer to 538118611Snjl * the (locked) directory inode in ndp->ni_dvp. 539118611Snjl * The pathname buffer is saved so that the name 540118611Snjl * can be obtained later. 541118611Snjl * 542118611Snjl * NB - if the directory is unlocked, then this 543118611Snjl * information cannot be used. 544118611Snjl */ 545118611Snjl cnp->cn_flags |= SAVENAME; 546118611Snjl if (!lockparent) 547118611Snjl VOP_UNLOCK(vdp, 0, td); 548118611Snjl return (EJUSTRETURN); 549118611Snjl } 550118611Snjl /* 551118611Snjl * Insert name into cache (as non-existent) if appropriate. 552118611Snjl */ 553118611Snjl if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE) 554118611Snjl cache_enter(vdp, *vpp, cnp); 555118611Snjl return (ENOENT); 556118611Snjl 557118611Snjlfound: 558118611Snjl if (numdirpasses == 2) 559118611Snjl nchstats.ncs_pass2++; 560118611Snjl /* 561118611Snjl * Check that directory length properly reflects presence 562118611Snjl * of this entry. 563118611Snjl */ 564118611Snjl if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len) 565167802Sjkim > dp->i_size) { 566167802Sjkim ext2_dirbad(dp, dp->i_offset, "i_size too small"); 567167802Sjkim dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len); 568167802Sjkim dp->i_flag |= IN_CHANGE | IN_UPDATE; 569167802Sjkim } 570167802Sjkim brelse(bp); 571167802Sjkim 572167802Sjkim /* 573167802Sjkim * Found component in pathname. 574167802Sjkim * If the final component of path name, save information 575167802Sjkim * in the cache as to where the entry was found. 576167802Sjkim */ 577167802Sjkim if ((flags & ISLASTCN) && nameiop == LOOKUP) 578167802Sjkim dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1); 579167802Sjkim 580118611Snjl /* 581118611Snjl * If deleting, and at end of pathname, return 582118611Snjl * parameters which can be used to remove file. 583118611Snjl * If the wantparent flag isn't set, we return only 584118611Snjl * the directory (in ndp->ni_dvp), otherwise we go 585118611Snjl * on and lock the inode, being careful with ".". 586118611Snjl */ 587118611Snjl if (nameiop == DELETE && (flags & ISLASTCN)) { 588118611Snjl /* 589118611Snjl * Write access to directory required to delete files. 590118611Snjl */ 591118611Snjl if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 592118611Snjl return (error); 593118611Snjl /* 594118611Snjl * Return pointer to current entry in dp->i_offset, 595118611Snjl * and distance past previous entry (if there 596118611Snjl * is a previous entry in this block) in dp->i_count. 597118611Snjl * Save directory inode pointer in ndp->ni_dvp for dirremove(). 598118611Snjl */ 599118611Snjl if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) 600118611Snjl dp->i_count = 0; 601118611Snjl else 602118611Snjl dp->i_count = dp->i_offset - prevoff; 603118611Snjl if (dp->i_number == dp->i_ino) { 604118611Snjl VREF(vdp); 605118611Snjl *vpp = vdp; 606118611Snjl return (0); 607118611Snjl } 608118611Snjl if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE, 609118611Snjl &tdp)) != 0) 610118611Snjl return (error); 611118611Snjl /* 612118611Snjl * If directory is "sticky", then user must own 613118611Snjl * the directory, or the file in it, else she 614118611Snjl * may not delete it (unless she's root). This 615118611Snjl * implements append-only directories. 616118611Snjl */ 617118611Snjl if ((dp->i_mode & ISVTX) && 618118611Snjl cred->cr_uid != 0 && 619118611Snjl cred->cr_uid != dp->i_uid && 620118611Snjl VTOI(tdp)->i_uid != cred->cr_uid) { 621118611Snjl vput(tdp); 622118611Snjl return (EPERM); 623118611Snjl } 624118611Snjl *vpp = tdp; 625118611Snjl if (!lockparent) 626118611Snjl VOP_UNLOCK(vdp, 0, td); 627118611Snjl return (0); 628118611Snjl } 629118611Snjl 630118611Snjl /* 631118611Snjl * If rewriting (RENAME), return the inode and the 632118611Snjl * information required to rewrite the present directory 633118611Snjl * Must get inode of directory entry to verify it's a 634118611Snjl * regular file, or empty directory. 635118611Snjl */ 636118611Snjl if (nameiop == RENAME && wantparent && 637118611Snjl (flags & ISLASTCN)) { 638118611Snjl if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 639118611Snjl return (error); 640118611Snjl /* 641118611Snjl * Careful about locking second inode. 642118611Snjl * This can only occur if the target is ".". 643118611Snjl */ 644118611Snjl if (dp->i_number == dp->i_ino) 645118611Snjl return (EISDIR); 646118611Snjl if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE, 647118611Snjl &tdp)) != 0) 648118611Snjl return (error); 649151937Sjkim *vpp = tdp; 650118611Snjl cnp->cn_flags |= SAVENAME; 651118611Snjl if (!lockparent) 652151937Sjkim VOP_UNLOCK(vdp, 0, td); 653151937Sjkim return (0); 654118611Snjl } 655118611Snjl 656118611Snjl /* 657118611Snjl * Step through the translation in the name. We do not `vput' the 658118611Snjl * directory because we may need it again if a symbolic link 659118611Snjl * is relative to the current directory. Instead we save it 660118611Snjl * unlocked as "pdp". We must get the target inode before unlocking 661118611Snjl * the directory to insure that the inode will not be removed 662118611Snjl * before we get it. We prevent deadlock by always fetching 663118611Snjl * inodes from the root, moving down the directory tree. Thus 664118611Snjl * when following backward pointers ".." we must unlock the 665118611Snjl * parent directory before getting the requested directory. 666118611Snjl * There is a potential race condition here if both the current 667118611Snjl * and parent directories are removed before the VFS_VGET for the 668118611Snjl * inode associated with ".." returns. We hope that this occurs 669118611Snjl * infrequently since we cannot avoid this race condition without 670118611Snjl * implementing a sophisticated deadlock detection algorithm. 671 * Note also that this simple deadlock detection scheme will not 672 * work if the file system has any hard links other than ".." 673 * that point backwards in the directory structure. 674 */ 675 pdp = vdp; 676 if (flags & ISDOTDOT) { 677 VOP_UNLOCK(pdp, 0, td); /* race to get the inode */ 678 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE, 679 &tdp)) != 0) { 680 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td); 681 return (error); 682 } 683 if (lockparent && (flags & ISLASTCN) && 684 (error = vn_lock(pdp, LK_EXCLUSIVE, td))) { 685 vput(tdp); 686 return (error); 687 } 688 *vpp = tdp; 689 } else if (dp->i_number == dp->i_ino) { 690 VREF(vdp); /* we want ourself, ie "." */ 691 *vpp = vdp; 692 } else { 693 if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE, 694 &tdp)) != 0) 695 return (error); 696 if (!lockparent || !(flags & ISLASTCN)) 697 VOP_UNLOCK(pdp, 0, td); 698 *vpp = tdp; 699 } 700 701 /* 702 * Insert name into cache if appropriate. 703 */ 704 if (cnp->cn_flags & MAKEENTRY) 705 cache_enter(vdp, *vpp, cnp); 706 return (0); 707} 708 709void 710ext2_dirbad(ip, offset, how) 711 struct inode *ip; 712 doff_t offset; 713 char *how; 714{ 715 struct mount *mp; 716 717 mp = ITOV(ip)->v_mount; 718 (void)printf("%s: bad dir ino %lu at offset %ld: %s\n", 719 mp->mnt_stat.f_mntonname, (u_long)ip->i_number, (long)offset, how); 720 if ((mp->mnt_flag & MNT_RDONLY) == 0) 721 panic("ext2_dirbad: bad dir"); 722} 723 724/* 725 * Do consistency checking on a directory entry: 726 * record length must be multiple of 4 727 * entry must fit in rest of its DIRBLKSIZ block 728 * record must be large enough to contain entry 729 * name is not longer than MAXNAMLEN 730 * name must be as long as advertised, and null terminated 731 */ 732/* 733 * changed so that it confirms to ext2_check_dir_entry 734 */ 735static int 736ext2_dirbadentry(dp, de, entryoffsetinblock) 737 struct vnode *dp; 738 struct ext2_dir_entry_2 *de; 739 int entryoffsetinblock; 740{ 741 int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize; 742 743 char * error_msg = NULL; 744 745 if (de->rec_len < EXT2_DIR_REC_LEN(1)) 746 error_msg = "rec_len is smaller than minimal"; 747 else if (de->rec_len % 4 != 0) 748 error_msg = "rec_len % 4 != 0"; 749 else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len)) 750 error_msg = "reclen is too small for name_len"; 751 else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ) 752 error_msg = "directory entry across blocks"; 753 /* else LATER 754 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count) 755 error_msg = "inode out of bounds"; 756 */ 757 758 if (error_msg != NULL) { 759 printf("bad directory entry: %s\n", error_msg); 760 printf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n", 761 entryoffsetinblock, (unsigned long)de->inode, 762 de->rec_len, de->name_len); 763 } 764 return error_msg == NULL ? 0 : 1; 765} 766 767/* 768 * Write a directory entry after a call to namei, using the parameters 769 * that it left in nameidata. The argument ip is the inode which the new 770 * directory entry will refer to. Dvp is a pointer to the directory to 771 * be written, which was left locked by namei. Remaining parameters 772 * (dp->i_offset, dp->i_count) indicate how the space for the new 773 * entry is to be obtained. 774 */ 775int 776ext2_direnter(ip, dvp, cnp) 777 struct inode *ip; 778 struct vnode *dvp; 779 struct componentname *cnp; 780{ 781 struct ext2_dir_entry_2 *ep, *nep; 782 struct inode *dp; 783 struct buf *bp; 784 struct ext2_dir_entry_2 newdir; 785 struct iovec aiov; 786 struct uio auio; 787 u_int dsize; 788 int error, loc, newentrysize, spacefree; 789 char *dirbuf; 790 int DIRBLKSIZ = ip->i_e2fs->s_blocksize; 791 792 793#if DIAGNOSTIC 794 if ((cnp->cn_flags & SAVENAME) == 0) 795 panic("direnter: missing name"); 796#endif 797 dp = VTOI(dvp); 798 newdir.inode = ip->i_number; 799 newdir.name_len = cnp->cn_namelen; 800 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es, 801 EXT2_FEATURE_INCOMPAT_FILETYPE)) 802 newdir.file_type = DTTOFT(IFTODT(ip->i_mode)); 803 else 804 newdir.file_type = EXT2_FT_UNKNOWN; 805 bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1); 806 newentrysize = EXT2_DIR_REC_LEN(newdir.name_len); 807 if (dp->i_count == 0) { 808 /* 809 * If dp->i_count is 0, then namei could find no 810 * space in the directory. Here, dp->i_offset will 811 * be on a directory block boundary and we will write the 812 * new entry into a fresh block. 813 */ 814 if (dp->i_offset & (DIRBLKSIZ - 1)) 815 panic("ext2_direnter: newblk"); 816 auio.uio_offset = dp->i_offset; 817 newdir.rec_len = DIRBLKSIZ; 818 auio.uio_resid = newentrysize; 819 aiov.iov_len = newentrysize; 820 aiov.iov_base = (caddr_t)&newdir; 821 auio.uio_iov = &aiov; 822 auio.uio_iovcnt = 1; 823 auio.uio_rw = UIO_WRITE; 824 auio.uio_segflg = UIO_SYSSPACE; 825 auio.uio_td = (struct thread *)0; 826 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); 827 if (DIRBLKSIZ > 828 VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize) 829 /* XXX should grow with balloc() */ 830 panic("ext2_direnter: frag size"); 831 else if (!error) { 832 dp->i_size = roundup(dp->i_size, DIRBLKSIZ); 833 dp->i_flag |= IN_CHANGE; 834 } 835 return (error); 836 } 837 838 /* 839 * If dp->i_count is non-zero, then namei found space 840 * for the new entry in the range dp->i_offset to 841 * dp->i_offset + dp->i_count in the directory. 842 * To use this space, we may have to compact the entries located 843 * there, by copying them together towards the beginning of the 844 * block, leaving the free space in one usable chunk at the end. 845 */ 846 847 /* 848 * Increase size of directory if entry eats into new space. 849 * This should never push the size past a new multiple of 850 * DIRBLKSIZE. 851 * 852 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. 853 */ 854 if (dp->i_offset + dp->i_count > dp->i_size) 855 dp->i_size = dp->i_offset + dp->i_count; 856 /* 857 * Get the block containing the space for the new directory entry. 858 */ 859 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, 860 &bp)) != 0) 861 return (error); 862 /* 863 * Find space for the new entry. In the simple case, the entry at 864 * offset base will have the space. If it does not, then namei 865 * arranged that compacting the region dp->i_offset to 866 * dp->i_offset + dp->i_count would yield the 867 * space. 868 */ 869 ep = (struct ext2_dir_entry_2 *)dirbuf; 870 dsize = EXT2_DIR_REC_LEN(ep->name_len); 871 spacefree = ep->rec_len - dsize; 872 for (loc = ep->rec_len; loc < dp->i_count; ) { 873 nep = (struct ext2_dir_entry_2 *)(dirbuf + loc); 874 if (ep->inode) { 875 /* trim the existing slot */ 876 ep->rec_len = dsize; 877 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize); 878 } else { 879 /* overwrite; nothing there; header is ours */ 880 spacefree += dsize; 881 } 882 dsize = EXT2_DIR_REC_LEN(nep->name_len); 883 spacefree += nep->rec_len - dsize; 884 loc += nep->rec_len; 885 bcopy((caddr_t)nep, (caddr_t)ep, dsize); 886 } 887 /* 888 * Update the pointer fields in the previous entry (if any), 889 * copy in the new entry, and write out the block. 890 */ 891 if (ep->inode == 0) { 892 if (spacefree + dsize < newentrysize) 893 panic("ext2_direnter: compact1"); 894 newdir.rec_len = spacefree + dsize; 895 } else { 896 if (spacefree < newentrysize) 897 panic("ext2_direnter: compact2"); 898 newdir.rec_len = spacefree; 899 ep->rec_len = dsize; 900 ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize); 901 } 902 bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize); 903 error = BUF_WRITE(bp); 904 dp->i_flag |= IN_CHANGE | IN_UPDATE; 905 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size) 906 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, 907 cnp->cn_cred, cnp->cn_thread); 908 return (error); 909} 910 911/* 912 * Remove a directory entry after a call to namei, using 913 * the parameters which it left in nameidata. The entry 914 * dp->i_offset contains the offset into the directory of the 915 * entry to be eliminated. The dp->i_count field contains the 916 * size of the previous record in the directory. If this 917 * is 0, the first entry is being deleted, so we need only 918 * zero the inode number to mark the entry as free. If the 919 * entry is not the first in the directory, we must reclaim 920 * the space of the now empty record by adding the record size 921 * to the size of the previous entry. 922 */ 923int 924ext2_dirremove(dvp, cnp) 925 struct vnode *dvp; 926 struct componentname *cnp; 927{ 928 struct inode *dp; 929 struct ext2_dir_entry_2 *ep; 930 struct buf *bp; 931 int error; 932 933 dp = VTOI(dvp); 934 if (dp->i_count == 0) { 935 /* 936 * First entry in block: set d_ino to zero. 937 */ 938 if ((error = 939 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, 940 &bp)) != 0) 941 return (error); 942 ep->inode = 0; 943 error = BUF_WRITE(bp); 944 dp->i_flag |= IN_CHANGE | IN_UPDATE; 945 return (error); 946 } 947 /* 948 * Collapse new free space into previous entry. 949 */ 950 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count), 951 (char **)&ep, &bp)) != 0) 952 return (error); 953 ep->rec_len += dp->i_reclen; 954 error = BUF_WRITE(bp); 955 dp->i_flag |= IN_CHANGE | IN_UPDATE; 956 return (error); 957} 958 959/* 960 * Rewrite an existing directory entry to point at the inode 961 * supplied. The parameters describing the directory entry are 962 * set up by a call to namei. 963 */ 964int 965ext2_dirrewrite(dp, ip, cnp) 966 struct inode *dp, *ip; 967 struct componentname *cnp; 968{ 969 struct buf *bp; 970 struct ext2_dir_entry_2 *ep; 971 struct vnode *vdp = ITOV(dp); 972 int error; 973 974 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, 975 &bp)) != 0) 976 return (error); 977 ep->inode = ip->i_number; 978 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es, 979 EXT2_FEATURE_INCOMPAT_FILETYPE)) 980 ep->file_type = DTTOFT(IFTODT(ip->i_mode)); 981 else 982 ep->file_type = EXT2_FT_UNKNOWN; 983 error = BUF_WRITE(bp); 984 dp->i_flag |= IN_CHANGE | IN_UPDATE; 985 return (error); 986} 987 988/* 989 * Check if a directory is empty or not. 990 * Inode supplied must be locked. 991 * 992 * Using a struct dirtemplate here is not precisely 993 * what we want, but better than using a struct direct. 994 * 995 * NB: does not handle corrupted directories. 996 */ 997int 998ext2_dirempty(ip, parentino, cred) 999 struct inode *ip; 1000 ino_t parentino; 1001 struct ucred *cred; 1002{ 1003 off_t off; 1004 struct dirtemplate dbuf; 1005 struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf; 1006 int error, count, namlen; 1007#define MINDIRSIZ (sizeof (struct dirtemplate) / 2) 1008 1009 for (off = 0; off < ip->i_size; off += dp->rec_len) { 1010 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, 1011 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred, 1012 NOCRED, &count, (struct thread *)0); 1013 /* 1014 * Since we read MINDIRSIZ, residual must 1015 * be 0 unless we're at end of file. 1016 */ 1017 if (error || count != 0) 1018 return (0); 1019 /* avoid infinite loops */ 1020 if (dp->rec_len == 0) 1021 return (0); 1022 /* skip empty entries */ 1023 if (dp->inode == 0) 1024 continue; 1025 /* accept only "." and ".." */ 1026 namlen = dp->name_len; 1027 if (namlen > 2) 1028 return (0); 1029 if (dp->name[0] != '.') 1030 return (0); 1031 /* 1032 * At this point namlen must be 1 or 2. 1033 * 1 implies ".", 2 implies ".." if second 1034 * char is also "." 1035 */ 1036 if (namlen == 1) 1037 continue; 1038 if (dp->name[1] == '.' && dp->inode == parentino) 1039 continue; 1040 return (0); 1041 } 1042 return (1); 1043} 1044 1045/* 1046 * Check if source directory is in the path of the target directory. 1047 * Target is supplied locked, source is unlocked. 1048 * The target is always vput before returning. 1049 */ 1050int 1051ext2_checkpath(source, target, cred) 1052 struct inode *source, *target; 1053 struct ucred *cred; 1054{ 1055 struct vnode *vp; 1056 int error, rootino, namlen; 1057 struct dirtemplate dirbuf; 1058 1059 vp = ITOV(target); 1060 if (target->i_number == source->i_number) { 1061 error = EEXIST; 1062 goto out; 1063 } 1064 rootino = ROOTINO; 1065 error = 0; 1066 if (target->i_number == rootino) 1067 goto out; 1068 1069 for (;;) { 1070 if (vp->v_type != VDIR) { 1071 error = ENOTDIR; 1072 break; 1073 } 1074 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, 1075 sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE, 1076 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, (int *)0, 1077 (struct thread *)0); 1078 if (error != 0) 1079 break; 1080 namlen = dirbuf.dotdot_type; /* like ufs little-endian */ 1081 if (namlen != 2 || 1082 dirbuf.dotdot_name[0] != '.' || 1083 dirbuf.dotdot_name[1] != '.') { 1084 error = ENOTDIR; 1085 break; 1086 } 1087 if (dirbuf.dotdot_ino == source->i_number) { 1088 error = EINVAL; 1089 break; 1090 } 1091 if (dirbuf.dotdot_ino == rootino) 1092 break; 1093 vput(vp); 1094 if ((error = VFS_VGET(vp->v_mount, dirbuf.dotdot_ino, 1095 LK_EXCLUSIVE, &vp)) != 0) { 1096 vp = NULL; 1097 break; 1098 } 1099 } 1100 1101out: 1102 if (error == ENOTDIR) 1103 printf("checkpath: .. not a directory\n"); 1104 if (vp != NULL) 1105 vput(vp); 1106 return (error); 1107} 1108