Annotation of src/sys/ufs/lfs/ulfs_lookup.c, Revision 1.25
1.25 ! mlelstv 1: /* $NetBSD: ulfs_lookup.c,v 1.24 2015/05/31 15:48:03 hannken Exp $ */
1.1 dholland 2: /* from NetBSD: ufs_lookup.c,v 1.122 2013/01/22 09:39:18 dholland Exp */
3:
4: /*
5: * Copyright (c) 1989, 1993
6: * The Regents of the University of California. All rights reserved.
7: * (c) UNIX System Laboratories, Inc.
8: * All or some portions of this file are derived from material licensed
9: * to the University of California by American Telephone and Telegraph
10: * Co. or Unix System Laboratories, Inc. and are reproduced herein with
11: * the permission of UNIX System Laboratories, Inc.
12: *
13: * Redistribution and use in source and binary forms, with or without
14: * modification, are permitted provided that the following conditions
15: * are met:
16: * 1. Redistributions of source code must retain the above copyright
17: * notice, this list of conditions and the following disclaimer.
18: * 2. Redistributions in binary form must reproduce the above copyright
19: * notice, this list of conditions and the following disclaimer in the
20: * documentation and/or other materials provided with the distribution.
21: * 3. Neither the name of the University nor the names of its contributors
22: * may be used to endorse or promote products derived from this software
23: * without specific prior written permission.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35: * SUCH DAMAGE.
36: *
37: * @(#)ufs_lookup.c 8.9 (Berkeley) 8/11/94
38: */
39:
40: #include <sys/cdefs.h>
1.25 ! mlelstv 41: __KERNEL_RCSID(0, "$NetBSD: ulfs_lookup.c,v 1.24 2015/05/31 15:48:03 hannken Exp $");
1.1 dholland 42:
43: #ifdef _KERNEL_OPT
1.3 dholland 44: #include "opt_lfs.h"
1.1 dholland 45: #endif
46:
47: #include <sys/param.h>
48: #include <sys/systm.h>
49: #include <sys/namei.h>
50: #include <sys/buf.h>
51: #include <sys/file.h>
52: #include <sys/stat.h>
53: #include <sys/mount.h>
54: #include <sys/vnode.h>
55: #include <sys/kernel.h>
56: #include <sys/kauth.h>
57: #include <sys/wapbl.h>
58: #include <sys/fstrans.h>
59: #include <sys/proc.h>
60: #include <sys/kmem.h>
61:
1.13 dholland 62: #include <ufs/lfs/lfs_extern.h>
63:
1.2 dholland 64: #include <ufs/lfs/ulfs_inode.h>
1.3 dholland 65: #ifdef LFS_DIRHASH
1.2 dholland 66: #include <ufs/lfs/ulfs_dirhash.h>
1.1 dholland 67: #endif
1.2 dholland 68: #include <ufs/lfs/ulfsmount.h>
69: #include <ufs/lfs/ulfs_extern.h>
70: #include <ufs/lfs/ulfs_bswap.h>
1.1 dholland 71:
72: #include <miscfs/genfs/genfs.h>
73:
74: #ifdef DIAGNOSTIC
1.5 dholland 75: int lfs_dirchk = 1;
1.1 dholland 76: #else
1.5 dholland 77: int lfs_dirchk = 0;
1.1 dholland 78: #endif
79:
80: /*
81: * Convert a component of a pathname into a pointer to a locked inode.
82: * This is a very central and rather complicated routine.
83: * If the file system is not maintained in a strict tree hierarchy,
84: * this can result in a deadlock situation (see comments in code below).
85: *
86: * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
87: * on whether the name is to be looked up, created, renamed, or deleted.
88: * When CREATE, RENAME, or DELETE is specified, information usable in
89: * creating, renaming, or deleting a directory entry may be calculated.
90: * If flag has LOCKPARENT or'ed into it and the target of the pathname
91: * exists, lookup returns both the target and its parent directory locked.
92: * When creating or renaming and LOCKPARENT is specified, the target may
93: * not be ".". When deleting and LOCKPARENT is specified, the target may
94: * be "."., but the caller must check to ensure it does an vrele and vput
95: * instead of two vputs.
96: *
1.4 dholland 97: * Overall outline of ulfs_lookup:
1.1 dholland 98: *
99: * check accessibility of directory
100: * look for name in cache, if found, then if at end of path
101: * and deleting or creating, drop it, else return name
102: * search for name in directory, to found or notfound
103: * notfound:
104: * if creating, return locked directory, leaving info on available slots
105: * else return error
106: * found:
107: * if at end of path and deleting, return information to allow delete
108: * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
109: * inode and return info to allow rewrite
110: * if not at end, add name to cache; if at end and neither creating
111: * nor deleting, add name to cache
112: */
113: int
1.4 dholland 114: ulfs_lookup(void *v)
1.1 dholland 115: {
1.19 hannken 116: struct vop_lookup_v2_args /* {
1.1 dholland 117: struct vnode *a_dvp;
118: struct vnode **a_vpp;
119: struct componentname *a_cnp;
120: } */ *ap = v;
121: struct vnode *vdp = ap->a_dvp; /* vnode for directory being searched */
122: struct inode *dp = VTOI(vdp); /* inode for directory being searched */
123: struct buf *bp; /* a buffer of directory entries */
1.7 dholland 124: struct lfs_direct *ep; /* the current directory entry */
1.1 dholland 125: int entryoffsetinblock; /* offset of ep in bp's buffer */
126: enum {
127: NONE, /* need to search a slot for our new entry */
128: COMPACT, /* a compaction can make a slot in the current
129: DIRBLKSIZ block */
130: FOUND, /* found a slot (or no need to search) */
131: } slotstatus;
132: doff_t slotoffset; /* offset of area with free space.
133: a special value -1 for invalid */
134: int slotsize; /* size of area at slotoffset */
135: int slotfreespace; /* accumulated amount of space free in
136: the current DIRBLKSIZ block */
137: int slotneeded; /* size of the entry we're seeking */
138: int numdirpasses; /* strategy for directory search */
139: doff_t endsearch; /* offset to end directory search */
140: doff_t prevoff; /* previous value of ulr_offset */
1.24 hannken 141: struct vnode *tdp; /* returned by vcache_get */
1.1 dholland 142: doff_t enduseful; /* pointer past last used dir slot.
143: used for directory truncation. */
144: u_long bmask; /* block offset mask */
145: int error;
146: struct vnode **vpp = ap->a_vpp;
147: struct componentname *cnp = ap->a_cnp;
148: kauth_cred_t cred = cnp->cn_cred;
149: int flags;
150: int nameiop = cnp->cn_nameiop;
1.15 dholland 151: struct lfs *fs = dp->i_lfs;
152: const int needswap = ULFS_MPNEEDSWAP(fs);
153: int dirblksiz = fs->um_dirblksiz;
1.1 dholland 154: ino_t foundino;
1.4 dholland 155: struct ulfs_lookup_results *results;
1.1 dholland 156: int iswhiteout; /* temp result from cache_lookup() */
157:
158: flags = cnp->cn_flags;
159:
160: bp = NULL;
161: slotoffset = -1;
162: *vpp = NULL;
163: endsearch = 0; /* silence compiler warning */
164:
165: /*
166: * Produce the auxiliary lookup results into i_crap. Increment
167: * its serial number so elsewhere we can tell if we're using
168: * stale results. This should not be done this way. XXX.
169: */
170: results = &dp->i_crap;
171: dp->i_crapcounter++;
172:
173: /*
174: * Check accessiblity of directory.
175: */
176: if ((error = VOP_ACCESS(vdp, VEXEC, cred)) != 0)
177: return (error);
178:
179: if ((flags & ISLASTCN) && (vdp->v_mount->mnt_flag & MNT_RDONLY) &&
180: (nameiop == DELETE || nameiop == RENAME))
181: return (EROFS);
182:
183: /*
184: * We now have a segment name to search for, and a directory to search.
185: *
186: * Before tediously performing a linear scan of the directory,
187: * check the name cache to see if the directory/name pair
188: * we are looking for is known already.
189: */
190: if (cache_lookup(vdp, cnp->cn_nameptr, cnp->cn_namelen,
191: cnp->cn_nameiop, cnp->cn_flags, &iswhiteout, vpp)) {
192: if (iswhiteout) {
193: cnp->cn_flags |= ISWHITEOUT;
194: }
195: return *vpp == NULLVP ? ENOENT : 0;
196: }
197: if (iswhiteout) {
198: /*
199: * The namecache set iswhiteout without finding a
200: * cache entry. As of this writing (20121014), this
201: * can happen if there was a whiteout entry that has
202: * been invalidated by the lookup. It is not clear if
203: * it is correct to set ISWHITEOUT in this case or
204: * not; however, doing so retains the prior behavior,
205: * so we'll go with that until some clearer answer
206: * appears. XXX
207: */
208: cnp->cn_flags |= ISWHITEOUT;
209: }
210:
211: fstrans_start(vdp->v_mount, FSTRANS_SHARED);
212:
213: /*
214: * Suppress search for slots unless creating
215: * file and at end of pathname, in which case
216: * we watch for a place to put the new file in
217: * case it doesn't already exist.
218: */
219: slotstatus = FOUND;
220: slotfreespace = slotsize = slotneeded = 0;
221: if ((nameiop == CREATE || nameiop == RENAME) && (flags & ISLASTCN)) {
222: slotstatus = NONE;
1.9 dholland 223: slotneeded = LFS_DIRECTSIZ(cnp->cn_namelen);
1.1 dholland 224: }
225:
226: /*
227: * If there is cached information on a previous search of
228: * this directory, pick up where we last left off.
229: * We cache only lookups as these are the most common
230: * and have the greatest payoff. Caching CREATE has little
231: * benefit as it usually must search the entire directory
232: * to determine that the entry does not exist. Caching the
233: * location of the last DELETE or RENAME has not reduced
234: * profiling time and hence has been removed in the interest
235: * of simplicity.
236: */
237: bmask = vdp->v_mount->mnt_stat.f_iosize - 1;
238:
1.3 dholland 239: #ifdef LFS_DIRHASH
1.1 dholland 240: /*
241: * Use dirhash for fast operations on large directories. The logic
242: * to determine whether to hash the directory is contained within
1.4 dholland 243: * ulfsdirhash_build(); a zero return means that it decided to hash
1.1 dholland 244: * this directory and it successfully built up the hash table.
245: */
1.4 dholland 246: if (ulfsdirhash_build(dp) == 0) {
1.1 dholland 247: /* Look for a free slot if needed. */
248: enduseful = dp->i_size;
249: if (slotstatus != FOUND) {
1.4 dholland 250: slotoffset = ulfsdirhash_findfree(dp, slotneeded,
1.1 dholland 251: &slotsize);
252: if (slotoffset >= 0) {
253: slotstatus = COMPACT;
1.4 dholland 254: enduseful = ulfsdirhash_enduseful(dp);
1.1 dholland 255: if (enduseful < 0)
256: enduseful = dp->i_size;
257: }
258: }
259: /* Look up the component. */
260: numdirpasses = 1;
261: entryoffsetinblock = 0; /* silence compiler warning */
1.4 dholland 262: switch (ulfsdirhash_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen,
1.1 dholland 263: &results->ulr_offset, &bp, nameiop == DELETE ? &prevoff : NULL)) {
264: case 0:
1.7 dholland 265: ep = (struct lfs_direct *)((char *)bp->b_data +
1.1 dholland 266: (results->ulr_offset & bmask));
267: goto foundentry;
268: case ENOENT:
269: results->ulr_offset = roundup(dp->i_size, dirblksiz);
270: goto notfound;
271: default:
272: /* Something failed; just do a linear search. */
273: break;
274: }
275: }
1.3 dholland 276: #endif /* LFS_DIRHASH */
1.1 dholland 277:
278: if (nameiop != LOOKUP || results->ulr_diroff == 0 ||
279: results->ulr_diroff >= dp->i_size) {
280: entryoffsetinblock = 0;
281: results->ulr_offset = 0;
282: numdirpasses = 1;
283: } else {
284: results->ulr_offset = results->ulr_diroff;
285: if ((entryoffsetinblock = results->ulr_offset & bmask) &&
1.4 dholland 286: (error = ulfs_blkatoff(vdp, (off_t)results->ulr_offset,
1.1 dholland 287: NULL, &bp, false)))
288: goto out;
289: numdirpasses = 2;
1.21 joerg 290: namecache_count_2passes();
1.1 dholland 291: }
292: prevoff = results->ulr_offset;
293: endsearch = roundup(dp->i_size, dirblksiz);
294: enduseful = 0;
295:
296: searchloop:
297: while (results->ulr_offset < endsearch) {
298: if (curcpu()->ci_schedstate.spc_flags & SPCF_SHOULDYIELD)
299: preempt();
300: /*
301: * If necessary, get the next directory block.
302: */
303: if ((results->ulr_offset & bmask) == 0) {
304: if (bp != NULL)
305: brelse(bp, 0);
1.4 dholland 306: error = ulfs_blkatoff(vdp, (off_t)results->ulr_offset,
1.1 dholland 307: NULL, &bp, false);
308: if (error)
309: goto out;
310: entryoffsetinblock = 0;
311: }
312: /*
313: * If still looking for a slot, and at a DIRBLKSIZ
314: * boundary, have to start looking for free space again.
315: */
316: if (slotstatus == NONE &&
317: (entryoffsetinblock & (dirblksiz - 1)) == 0) {
318: slotoffset = -1;
319: slotfreespace = 0;
320: }
321: /*
322: * Get pointer to next entry.
323: * Full validation checks are slow, so we only check
324: * enough to insure forward progress through the
325: * directory. Complete checks can be run by patching
1.5 dholland 326: * "lfs_dirchk" to be true.
1.1 dholland 327: */
328: KASSERT(bp != NULL);
1.7 dholland 329: ep = (struct lfs_direct *)((char *)bp->b_data + entryoffsetinblock);
1.1 dholland 330: if (ep->d_reclen == 0 ||
1.5 dholland 331: (lfs_dirchk && ulfs_dirbadentry(vdp, ep, entryoffsetinblock))) {
1.1 dholland 332: int i;
333:
1.4 dholland 334: ulfs_dirbad(dp, results->ulr_offset, "mangled entry");
1.1 dholland 335: i = dirblksiz - (entryoffsetinblock & (dirblksiz - 1));
336: results->ulr_offset += i;
337: entryoffsetinblock += i;
338: continue;
339: }
340:
341: /*
342: * If an appropriate sized slot has not yet been found,
343: * check to see if one is available. Also accumulate space
344: * in the current block so that we can determine if
345: * compaction is viable.
346: */
347: if (slotstatus != FOUND) {
1.4 dholland 348: int size = ulfs_rw16(ep->d_reclen, needswap);
1.1 dholland 349:
350: if (ep->d_ino != 0)
1.9 dholland 351: size -= LFS_DIRSIZ(FSFMT(vdp), ep, needswap);
1.1 dholland 352: if (size > 0) {
353: if (size >= slotneeded) {
354: slotstatus = FOUND;
355: slotoffset = results->ulr_offset;
1.4 dholland 356: slotsize = ulfs_rw16(ep->d_reclen,
1.1 dholland 357: needswap);
358: } else if (slotstatus == NONE) {
359: slotfreespace += size;
360: if (slotoffset == -1)
361: slotoffset = results->ulr_offset;
362: if (slotfreespace >= slotneeded) {
363: slotstatus = COMPACT;
364: slotsize = results->ulr_offset +
1.4 dholland 365: ulfs_rw16(ep->d_reclen,
1.1 dholland 366: needswap) -
367: slotoffset;
368: }
369: }
370: }
371: }
372:
373: /*
374: * Check for a name match.
375: */
376: if (ep->d_ino) {
377: int namlen;
378:
379: #if (BYTE_ORDER == LITTLE_ENDIAN)
380: if (FSFMT(vdp) && needswap == 0)
381: namlen = ep->d_type;
382: else
383: namlen = ep->d_namlen;
384: #else
385: if (FSFMT(vdp) && needswap != 0)
386: namlen = ep->d_type;
387: else
388: namlen = ep->d_namlen;
389: #endif
390: if (namlen == cnp->cn_namelen &&
391: !memcmp(cnp->cn_nameptr, ep->d_name,
392: (unsigned)namlen)) {
1.3 dholland 393: #ifdef LFS_DIRHASH
1.1 dholland 394: foundentry:
395: #endif
396: /*
397: * Save directory entry's inode number and
398: * reclen, and release directory buffer.
399: */
1.7 dholland 400: if (!FSFMT(vdp) && ep->d_type == LFS_DT_WHT) {
1.1 dholland 401: slotstatus = FOUND;
402: slotoffset = results->ulr_offset;
1.4 dholland 403: slotsize = ulfs_rw16(ep->d_reclen,
1.1 dholland 404: needswap);
405: results->ulr_reclen = slotsize;
406: /*
407: * This is used to set
408: * results->ulr_endoff,
1.4 dholland 409: * which may be used by ulfs_direnter()
1.1 dholland 410: * as a length to truncate the
411: * directory to. Therefore, it must
412: * point past the end of the last
413: * non-empty directory entry. We don't
414: * know where that is in this case, so
415: * we effectively disable shrinking by
416: * using the existing size of the
417: * directory.
418: *
419: * Note that we wouldn't expect to
420: * shrink the directory while rewriting
421: * an existing entry anyway.
422: */
423: enduseful = endsearch;
424: cnp->cn_flags |= ISWHITEOUT;
425: numdirpasses--;
426: goto notfound;
427: }
1.4 dholland 428: foundino = ulfs_rw32(ep->d_ino, needswap);
1.1 dholland 429: results->ulr_reclen =
1.4 dholland 430: ulfs_rw16(ep->d_reclen, needswap);
1.1 dholland 431: goto found;
432: }
433: }
434: prevoff = results->ulr_offset;
1.4 dholland 435: results->ulr_offset += ulfs_rw16(ep->d_reclen, needswap);
436: entryoffsetinblock += ulfs_rw16(ep->d_reclen, needswap);
1.1 dholland 437: if (ep->d_ino)
438: enduseful = results->ulr_offset;
439: }
440: notfound:
441: /*
442: * If we started in the middle of the directory and failed
443: * to find our target, we must check the beginning as well.
444: */
445: if (numdirpasses == 2) {
446: numdirpasses--;
447: results->ulr_offset = 0;
448: endsearch = results->ulr_diroff;
449: goto searchloop;
450: }
451: if (bp != NULL)
452: brelse(bp, 0);
453: /*
454: * If creating, and at end of pathname and current
455: * directory has not been removed, then can consider
456: * allowing file to be created.
457: */
458: if ((nameiop == CREATE || nameiop == RENAME ||
459: (nameiop == DELETE &&
460: (cnp->cn_flags & DOWHITEOUT) &&
461: (cnp->cn_flags & ISWHITEOUT))) &&
462: (flags & ISLASTCN) && dp->i_nlink != 0) {
463: /*
464: * Access for write is interpreted as allowing
465: * creation of files in the directory.
466: */
467: error = VOP_ACCESS(vdp, VWRITE, cred);
468: if (error)
469: goto out;
470: /*
471: * Return an indication of where the new directory
472: * entry should be put. If we didn't find a slot,
473: * then set results->ulr_count to 0 indicating
474: * that the new slot belongs at the end of the
475: * directory. If we found a slot, then the new entry
476: * can be put in the range from results->ulr_offset to
477: * results->ulr_offset + results->ulr_count.
478: */
479: if (slotstatus == NONE) {
480: results->ulr_offset = roundup(dp->i_size, dirblksiz);
481: results->ulr_count = 0;
482: enduseful = results->ulr_offset;
483: } else if (nameiop == DELETE) {
484: results->ulr_offset = slotoffset;
485: if ((results->ulr_offset & (dirblksiz - 1)) == 0)
486: results->ulr_count = 0;
487: else
488: results->ulr_count =
489: results->ulr_offset - prevoff;
490: } else {
491: results->ulr_offset = slotoffset;
492: results->ulr_count = slotsize;
493: if (enduseful < slotoffset + slotsize)
494: enduseful = slotoffset + slotsize;
495: }
496: results->ulr_endoff = roundup(enduseful, dirblksiz);
497: #if 0 /* commented out by dbj. none of the on disk fields changed */
498: dp->i_flag |= IN_CHANGE | IN_UPDATE;
499: #endif
500: /*
501: * We return with the directory locked, so that
502: * the parameters we set up above will still be
503: * valid if we actually decide to do a direnter().
504: * We return ni_vp == NULL to indicate that the entry
505: * does not currently exist; we leave a pointer to
506: * the (locked) directory inode in ndp->ni_dvp.
507: *
508: * NB - if the directory is unlocked, then this
509: * information cannot be used.
510: */
511: error = EJUSTRETURN;
512: goto out;
513: }
514: /*
515: * Insert name into cache (as non-existent) if appropriate.
516: */
517: if (nameiop != CREATE) {
518: cache_enter(vdp, *vpp, cnp->cn_nameptr, cnp->cn_namelen,
519: cnp->cn_flags);
520: }
521: error = ENOENT;
522: goto out;
523:
524: found:
525: if (numdirpasses == 2)
1.21 joerg 526: namecache_count_pass2();
1.1 dholland 527: /*
528: * Check that directory length properly reflects presence
529: * of this entry.
530: */
1.9 dholland 531: if (results->ulr_offset + LFS_DIRSIZ(FSFMT(vdp), ep, needswap) > dp->i_size) {
1.4 dholland 532: ulfs_dirbad(dp, results->ulr_offset, "i_size too small");
1.1 dholland 533: dp->i_size =
1.9 dholland 534: results->ulr_offset + LFS_DIRSIZ(FSFMT(vdp), ep, needswap);
1.1 dholland 535: DIP_ASSIGN(dp, size, dp->i_size);
536: dp->i_flag |= IN_CHANGE | IN_UPDATE;
537: }
538: brelse(bp, 0);
539:
540: /*
541: * Found component in pathname.
542: * If the final component of path name, save information
543: * in the cache as to where the entry was found.
544: */
545: if ((flags & ISLASTCN) && nameiop == LOOKUP)
546: results->ulr_diroff = results->ulr_offset &~ (dirblksiz - 1);
547:
548: /*
549: * If deleting, and at end of pathname, return
550: * parameters which can be used to remove file.
551: * Lock the inode, being careful with ".".
552: */
553: if (nameiop == DELETE && (flags & ISLASTCN)) {
554: /*
555: * Return pointer to current entry in results->ulr_offset,
556: * and distance past previous entry (if there
557: * is a previous entry in this block) in results->ulr_count.
558: * Save directory inode pointer in ndp->ni_dvp for dirremove().
559: */
560: if ((results->ulr_offset & (dirblksiz - 1)) == 0)
561: results->ulr_count = 0;
562: else
563: results->ulr_count = results->ulr_offset - prevoff;
564: if (dp->i_number == foundino) {
565: vref(vdp);
566: tdp = vdp;
567: } else {
1.24 hannken 568: error = vcache_get(vdp->v_mount,
569: &foundino, sizeof(foundino), &tdp);
1.1 dholland 570: if (error)
571: goto out;
572: }
573: /*
574: * Write access to directory required to delete files.
575: */
576: error = VOP_ACCESS(vdp, VWRITE, cred);
577: if (error) {
1.24 hannken 578: vrele(tdp);
1.1 dholland 579: goto out;
580: }
581: /*
582: * If directory is "sticky", then user must own
583: * the directory, or the file in it, else she
584: * may not delete it (unless she's root). This
585: * implements append-only directories.
586: */
587: if (dp->i_mode & ISVTX) {
588: error = kauth_authorize_vnode(cred, KAUTH_VNODE_DELETE,
589: tdp, vdp, genfs_can_sticky(cred, dp->i_uid,
590: VTOI(tdp)->i_uid));
591: if (error) {
1.24 hannken 592: vrele(tdp);
1.1 dholland 593: error = EPERM;
594: goto out;
595: }
596: }
597: *vpp = tdp;
598: error = 0;
599: goto out;
600: }
601:
602: /*
603: * If rewriting (RENAME), return the inode and the
604: * information required to rewrite the present directory
605: * Must get inode of directory entry to verify it's a
606: * regular file, or empty directory.
607: */
608: if (nameiop == RENAME && (flags & ISLASTCN)) {
609: error = VOP_ACCESS(vdp, VWRITE, cred);
610: if (error)
611: goto out;
612: /*
613: * Careful about locking second inode.
614: * This can only occur if the target is ".".
615: */
616: if (dp->i_number == foundino) {
617: error = EISDIR;
618: goto out;
619: }
1.24 hannken 620: error = vcache_get(vdp->v_mount,
621: &foundino, sizeof(foundino), &tdp);
1.1 dholland 622: if (error)
623: goto out;
624: *vpp = tdp;
625: error = 0;
626: goto out;
627: }
628:
1.24 hannken 629: if (dp->i_number == foundino) {
1.1 dholland 630: vref(vdp); /* we want ourself, ie "." */
631: *vpp = vdp;
632: } else {
1.24 hannken 633: error = vcache_get(vdp->v_mount,
634: &foundino, sizeof(foundino), &tdp);
1.1 dholland 635: if (error)
636: goto out;
637: *vpp = tdp;
638: }
639:
640: /*
641: * Insert name into cache if appropriate.
642: */
643: cache_enter(vdp, *vpp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_flags);
644: error = 0;
645:
646: out:
647: fstrans_done(vdp->v_mount);
648: return error;
649: }
650:
651: void
1.4 dholland 652: ulfs_dirbad(struct inode *ip, doff_t offset, const char *how)
1.1 dholland 653: {
654: struct mount *mp;
655:
656: mp = ITOV(ip)->v_mount;
657: printf("%s: bad dir ino %llu at offset %d: %s\n",
658: mp->mnt_stat.f_mntonname, (unsigned long long)ip->i_number,
659: offset, how);
1.25 ! mlelstv 660: if ((mp->mnt_flag & MNT_RDONLY) == 0)
1.1 dholland 661: panic("bad dir");
662: }
663:
664: /*
665: * Do consistency checking on a directory entry:
666: * record length must be multiple of 4
667: * entry must fit in rest of its DIRBLKSIZ block
668: * record must be large enough to contain entry
1.8 dholland 669: * name is not longer than LFS_MAXNAMLEN
1.1 dholland 670: * name must be as long as advertised, and null terminated
671: */
672: int
1.7 dholland 673: ulfs_dirbadentry(struct vnode *dp, struct lfs_direct *ep, int entryoffsetinblock)
1.1 dholland 674: {
675: int i;
676: int namlen;
1.4 dholland 677: struct ulfsmount *ump = VFSTOULFS(dp->v_mount);
1.15 dholland 678: struct lfs *fs = ump->um_lfs;
679: const int needswap = ULFS_MPNEEDSWAP(fs);
680: int dirblksiz = fs->um_dirblksiz;
1.1 dholland 681:
682: #if (BYTE_ORDER == LITTLE_ENDIAN)
683: if (FSFMT(dp) && needswap == 0)
684: namlen = ep->d_type;
685: else
686: namlen = ep->d_namlen;
687: #else
688: if (FSFMT(dp) && needswap != 0)
689: namlen = ep->d_type;
690: else
691: namlen = ep->d_namlen;
692: #endif
1.4 dholland 693: if ((ulfs_rw16(ep->d_reclen, needswap) & 0x3) != 0 ||
694: ulfs_rw16(ep->d_reclen, needswap) >
1.1 dholland 695: dirblksiz - (entryoffsetinblock & (dirblksiz - 1)) ||
1.4 dholland 696: ulfs_rw16(ep->d_reclen, needswap) <
1.9 dholland 697: LFS_DIRSIZ(FSFMT(dp), ep, needswap) ||
1.8 dholland 698: namlen > LFS_MAXNAMLEN) {
1.1 dholland 699: /*return (1); */
700: printf("First bad, reclen=%#x, DIRSIZ=%lu, namlen=%d, "
701: "flags=%#x, entryoffsetinblock=%d, dirblksiz = %d\n",
1.4 dholland 702: ulfs_rw16(ep->d_reclen, needswap),
1.9 dholland 703: (u_long)LFS_DIRSIZ(FSFMT(dp), ep, needswap),
1.1 dholland 704: namlen, dp->v_mount->mnt_flag, entryoffsetinblock,
705: dirblksiz);
706: goto bad;
707: }
708: if (ep->d_ino == 0)
709: return (0);
710: for (i = 0; i < namlen; i++)
711: if (ep->d_name[i] == '\0') {
712: /*return (1); */
713: printf("Second bad\n");
714: goto bad;
715: }
716: if (ep->d_name[i])
717: goto bad;
718: return (0);
719: bad:
720: return (1);
721: }
722:
723: /*
724: * Construct a new directory entry after a call to namei, using the
725: * name in the componentname argument cnp. The argument ip is the
726: * inode to which the new directory entry will refer.
727: */
728: void
1.4 dholland 729: ulfs_makedirentry(struct inode *ip, struct componentname *cnp,
1.7 dholland 730: struct lfs_direct *newdirp)
1.1 dholland 731: {
732: newdirp->d_ino = ip->i_number;
733: newdirp->d_namlen = cnp->cn_namelen;
734: memcpy(newdirp->d_name, cnp->cn_nameptr, (size_t)cnp->cn_namelen);
735: newdirp->d_name[cnp->cn_namelen] = '\0';
736: if (FSFMT(ITOV(ip)))
737: newdirp->d_type = 0;
738: else
1.9 dholland 739: newdirp->d_type = LFS_IFTODT(ip->i_mode);
1.1 dholland 740: }
741:
742: /*
743: * Write a directory entry after a call to namei, using the parameters
1.4 dholland 744: * that ulfs_lookup left in nameidata and in the ulfs_lookup_results.
1.1 dholland 745: *
746: * DVP is the directory to be updated. It must be locked.
1.4 dholland 747: * ULR is the ulfs_lookup_results structure from the final lookup step.
1.1 dholland 748: * TVP is not used. (XXX: why is it here? remove it)
749: * DIRP is the new directory entry contents.
750: * CNP is the componentname from the final lookup step.
751: * NEWDIRBP is not used and (XXX) should be removed. The previous
752: * comment here said it was used by the now-removed softupdates code.
753: *
754: * The link count of the target inode is *not* incremented; the
755: * caller does that.
756: *
1.4 dholland 757: * If ulr->ulr_count is 0, ulfs_lookup did not find space to insert the
1.1 dholland 758: * directory entry. ulr_offset, which is the place to put the entry,
759: * should be on a block boundary (and should be at the end of the
760: * directory AFAIK) and a fresh block is allocated to put the new
761: * directory entry in.
762: *
1.4 dholland 763: * If ulr->ulr_count is not zero, ulfs_lookup found a slot to insert
1.1 dholland 764: * the entry into. This slot ranges from ulr_offset to ulr_offset +
765: * ulr_count. However, this slot may already be partially populated
766: * requiring compaction. See notes below.
767: *
768: * Furthermore, if ulr_count is not zero and ulr_endoff is not the
769: * same as i_size, the directory is truncated to size ulr_endoff.
770: */
771: int
1.4 dholland 772: ulfs_direnter(struct vnode *dvp, const struct ulfs_lookup_results *ulr,
1.7 dholland 773: struct vnode *tvp, struct lfs_direct *dirp,
1.1 dholland 774: struct componentname *cnp, struct buf *newdirbp)
775: {
776: kauth_cred_t cr;
777: int newentrysize;
778: struct inode *dp;
779: struct buf *bp;
780: u_int dsize;
1.7 dholland 781: struct lfs_direct *ep, *nep;
1.12 christos 782: int error, ret, lfs_blkoff, loc, spacefree;
1.1 dholland 783: char *dirbuf;
784: struct timespec ts;
1.4 dholland 785: struct ulfsmount *ump = VFSTOULFS(dvp->v_mount);
1.15 dholland 786: struct lfs *fs = ump->um_lfs;
787: const int needswap = ULFS_MPNEEDSWAP(fs);
788: int dirblksiz = fs->um_dirblksiz;
1.1 dholland 789:
790: error = 0;
791: cr = cnp->cn_cred;
792:
793: dp = VTOI(dvp);
1.9 dholland 794: newentrysize = LFS_DIRSIZ(0, dirp, 0);
1.1 dholland 795:
796: if (ulr->ulr_count == 0) {
797: /*
798: * If ulr_count is 0, then namei could find no
799: * space in the directory. Here, ulr_offset will
800: * be on a directory block boundary and we will write the
801: * new entry into a fresh block.
802: */
803: if (ulr->ulr_offset & (dirblksiz - 1))
1.4 dholland 804: panic("ulfs_direnter: newblk");
1.14 dholland 805: if ((error = lfs_balloc(dvp, (off_t)ulr->ulr_offset, dirblksiz,
1.1 dholland 806: cr, B_CLRBUF | B_SYNC, &bp)) != 0) {
807: return (error);
808: }
809: dp->i_size = ulr->ulr_offset + dirblksiz;
810: DIP_ASSIGN(dp, size, dp->i_size);
811: dp->i_flag |= IN_CHANGE | IN_UPDATE;
812: uvm_vnp_setsize(dvp, dp->i_size);
1.4 dholland 813: dirp->d_reclen = ulfs_rw16(dirblksiz, needswap);
814: dirp->d_ino = ulfs_rw32(dirp->d_ino, needswap);
1.1 dholland 815: if (FSFMT(dvp)) {
816: #if (BYTE_ORDER == LITTLE_ENDIAN)
817: if (needswap == 0) {
818: #else
819: if (needswap != 0) {
820: #endif
821: u_char tmp = dirp->d_namlen;
822: dirp->d_namlen = dirp->d_type;
823: dirp->d_type = tmp;
824: }
825: }
1.12 christos 826: lfs_blkoff = ulr->ulr_offset & (ump->um_mountp->mnt_stat.f_iosize - 1);
827: memcpy((char *)bp->b_data + lfs_blkoff, dirp, newentrysize);
1.3 dholland 828: #ifdef LFS_DIRHASH
1.1 dholland 829: if (dp->i_dirhash != NULL) {
1.4 dholland 830: ulfsdirhash_newblk(dp, ulr->ulr_offset);
831: ulfsdirhash_add(dp, dirp, ulr->ulr_offset);
1.12 christos 832: ulfsdirhash_checkblock(dp, (char *)bp->b_data + lfs_blkoff,
1.1 dholland 833: ulr->ulr_offset);
834: }
835: #endif
836: error = VOP_BWRITE(bp->b_vp, bp);
837: vfs_timestamp(&ts);
1.14 dholland 838: ret = lfs_update(dvp, &ts, &ts, UPDATE_DIROP);
1.1 dholland 839: if (error == 0)
840: return (ret);
841: return (error);
842: }
843:
844: /*
845: * If ulr_count is non-zero, then namei found space for the new
846: * entry in the range ulr_offset to ulr_offset + ulr_count
847: * in the directory. To use this space, we may have to compact
848: * the entries located there, by copying them together towards the
849: * beginning of the block, leaving the free space in one usable
850: * chunk at the end.
851: */
852:
853: /*
854: * Increase size of directory if entry eats into new space.
855: * This should never push the size past a new multiple of
856: * DIRBLKSIZ.
857: *
858: * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
859: */
860: if (ulr->ulr_offset + ulr->ulr_count > dp->i_size) {
861: #ifdef DIAGNOSTIC
1.4 dholland 862: printf("ulfs_direnter: reached 4.2-only block, "
1.1 dholland 863: "not supposed to happen\n");
864: #endif
865: dp->i_size = ulr->ulr_offset + ulr->ulr_count;
866: DIP_ASSIGN(dp, size, dp->i_size);
867: dp->i_flag |= IN_CHANGE | IN_UPDATE;
868: }
869: /*
870: * Get the block containing the space for the new directory entry.
871: */
1.4 dholland 872: error = ulfs_blkatoff(dvp, (off_t)ulr->ulr_offset, &dirbuf, &bp, true);
1.1 dholland 873: if (error) {
874: return (error);
875: }
876: /*
877: * Find space for the new entry. In the simple case, the entry at
878: * offset base will have the space. If it does not, then namei
879: * arranged that compacting the region ulr_offset to
880: * ulr_offset + ulr_count would yield the space.
881: */
1.7 dholland 882: ep = (struct lfs_direct *)dirbuf;
1.9 dholland 883: dsize = (ep->d_ino != 0) ? LFS_DIRSIZ(FSFMT(dvp), ep, needswap) : 0;
1.4 dholland 884: spacefree = ulfs_rw16(ep->d_reclen, needswap) - dsize;
885: for (loc = ulfs_rw16(ep->d_reclen, needswap); loc < ulr->ulr_count; ) {
1.1 dholland 886: uint16_t reclen;
887:
1.7 dholland 888: nep = (struct lfs_direct *)(dirbuf + loc);
1.1 dholland 889:
890: /* Trim the existing slot (NB: dsize may be zero). */
1.4 dholland 891: ep->d_reclen = ulfs_rw16(dsize, needswap);
1.7 dholland 892: ep = (struct lfs_direct *)((char *)ep + dsize);
1.1 dholland 893:
1.4 dholland 894: reclen = ulfs_rw16(nep->d_reclen, needswap);
1.1 dholland 895: loc += reclen;
896: if (nep->d_ino == 0) {
897: /*
898: * A mid-block unused entry. Such entries are
899: * never created by the kernel, but fsck_ffs
900: * can create them (and it doesn't fix them).
901: *
902: * Add up the free space, and initialise the
903: * relocated entry since we don't memcpy it.
904: */
905: spacefree += reclen;
906: ep->d_ino = 0;
907: dsize = 0;
908: continue;
909: }
1.9 dholland 910: dsize = LFS_DIRSIZ(FSFMT(dvp), nep, needswap);
1.1 dholland 911: spacefree += reclen - dsize;
1.3 dholland 912: #ifdef LFS_DIRHASH
1.1 dholland 913: if (dp->i_dirhash != NULL)
1.4 dholland 914: ulfsdirhash_move(dp, nep,
1.1 dholland 915: ulr->ulr_offset + ((char *)nep - dirbuf),
916: ulr->ulr_offset + ((char *)ep - dirbuf));
917: #endif
918: memcpy((void *)ep, (void *)nep, dsize);
919: }
920: /*
921: * Here, `ep' points to a directory entry containing `dsize' in-use
922: * bytes followed by `spacefree' unused bytes. If ep->d_ino == 0,
923: * then the entry is completely unused (dsize == 0). The value
924: * of ep->d_reclen is always indeterminate.
925: *
926: * Update the pointer fields in the previous entry (if any),
927: * copy in the new entry, and write out the block.
928: */
929: if (ep->d_ino == 0 ||
1.4 dholland 930: (ulfs_rw32(ep->d_ino, needswap) == ULFS_WINO &&
1.1 dholland 931: memcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) {
932: if (spacefree + dsize < newentrysize)
1.4 dholland 933: panic("ulfs_direnter: compact1");
1.1 dholland 934: dirp->d_reclen = spacefree + dsize;
935: } else {
936: if (spacefree < newentrysize)
1.4 dholland 937: panic("ulfs_direnter: compact2");
1.1 dholland 938: dirp->d_reclen = spacefree;
1.4 dholland 939: ep->d_reclen = ulfs_rw16(dsize, needswap);
1.7 dholland 940: ep = (struct lfs_direct *)((char *)ep + dsize);
1.1 dholland 941: }
1.4 dholland 942: dirp->d_reclen = ulfs_rw16(dirp->d_reclen, needswap);
943: dirp->d_ino = ulfs_rw32(dirp->d_ino, needswap);
1.1 dholland 944: if (FSFMT(dvp)) {
945: #if (BYTE_ORDER == LITTLE_ENDIAN)
946: if (needswap == 0) {
947: #else
948: if (needswap != 0) {
949: #endif
950: u_char tmp = dirp->d_namlen;
951: dirp->d_namlen = dirp->d_type;
952: dirp->d_type = tmp;
953: }
954: }
1.3 dholland 955: #ifdef LFS_DIRHASH
1.1 dholland 956: if (dp->i_dirhash != NULL && (ep->d_ino == 0 ||
957: dirp->d_reclen == spacefree))
1.4 dholland 958: ulfsdirhash_add(dp, dirp, ulr->ulr_offset + ((char *)ep - dirbuf));
1.1 dholland 959: #endif
960: memcpy((void *)ep, (void *)dirp, (u_int)newentrysize);
1.3 dholland 961: #ifdef LFS_DIRHASH
1.1 dholland 962: if (dp->i_dirhash != NULL)
1.4 dholland 963: ulfsdirhash_checkblock(dp, dirbuf -
1.1 dholland 964: (ulr->ulr_offset & (dirblksiz - 1)),
965: ulr->ulr_offset & ~(dirblksiz - 1));
966: #endif
967: error = VOP_BWRITE(bp->b_vp, bp);
968: dp->i_flag |= IN_CHANGE | IN_UPDATE;
969: /*
970: * If all went well, and the directory can be shortened, proceed
971: * with the truncation. Note that we have to unlock the inode for
972: * the entry that we just entered, as the truncation may need to
973: * lock other inodes which can lead to deadlock if we also hold a
974: * lock on the newly entered node.
975: */
976: if (error == 0 && ulr->ulr_endoff && ulr->ulr_endoff < dp->i_size) {
1.3 dholland 977: #ifdef LFS_DIRHASH
1.1 dholland 978: if (dp->i_dirhash != NULL)
1.4 dholland 979: ulfsdirhash_dirtrunc(dp, ulr->ulr_endoff);
1.1 dholland 980: #endif
1.14 dholland 981: (void) lfs_truncate(dvp, (off_t)ulr->ulr_endoff, IO_SYNC, cr);
1.1 dholland 982: }
983: return (error);
984: }
985:
986: /*
987: * Remove a directory entry after a call to namei, using the
1.4 dholland 988: * parameters that ulfs_lookup left in nameidata and in the
989: * ulfs_lookup_results.
1.1 dholland 990: *
991: * DVP is the directory to be updated. It must be locked.
1.4 dholland 992: * ULR is the ulfs_lookup_results structure from the final lookup step.
1.1 dholland 993: * IP, if not null, is the inode being unlinked.
994: * FLAGS may contain DOWHITEOUT.
995: * ISRMDIR is not used and (XXX) should be removed.
996: *
997: * If FLAGS contains DOWHITEOUT the entry is replaced with a whiteout
998: * instead of being cleared.
999: *
1000: * ulr->ulr_offset contains the position of the directory entry
1001: * to be removed.
1002: *
1003: * ulr->ulr_reclen contains the size of the directory entry to be
1004: * removed.
1005: *
1006: * ulr->ulr_count contains the size of the *previous* directory
1007: * entry. This allows finding it, for free space management. If
1008: * ulr_count is 0, the target entry is at the beginning of the
1009: * directory. (Does this ever happen? The first entry should be ".",
1010: * which should only be removed at rmdir time. Does rmdir come here
1011: * to clear out the "." and ".." entries? Perhaps, but I doubt it.)
1012: *
1013: * The space is marked free by adding it to the record length (not
1014: * name length) of the preceding entry. If the first entry becomes
1015: * free, it is marked free by setting the inode number to 0.
1016: *
1017: * The link count of IP is decremented. Note that this is not the
1.4 dholland 1018: * inverse behavior of ulfs_direnter, which does not adjust link
1.1 dholland 1019: * counts. Sigh.
1020: */
1021: int
1.4 dholland 1022: ulfs_dirremove(struct vnode *dvp, const struct ulfs_lookup_results *ulr,
1.1 dholland 1023: struct inode *ip, int flags, int isrmdir)
1024: {
1025: struct inode *dp = VTOI(dvp);
1.7 dholland 1026: struct lfs_direct *ep;
1.1 dholland 1027: struct buf *bp;
1028: int error;
1.15 dholland 1029: const int needswap = ULFS_MPNEEDSWAP(dp->i_lfs);
1.1 dholland 1030:
1031: if (flags & DOWHITEOUT) {
1032: /*
1.4 dholland 1033: * Whiteout entry: set d_ino to ULFS_WINO.
1.1 dholland 1034: */
1.4 dholland 1035: error = ulfs_blkatoff(dvp, (off_t)ulr->ulr_offset, (void *)&ep,
1.1 dholland 1036: &bp, true);
1037: if (error)
1038: return (error);
1.4 dholland 1039: ep->d_ino = ulfs_rw32(ULFS_WINO, needswap);
1.7 dholland 1040: ep->d_type = LFS_DT_WHT;
1.1 dholland 1041: goto out;
1042: }
1043:
1.4 dholland 1044: if ((error = ulfs_blkatoff(dvp,
1.1 dholland 1045: (off_t)(ulr->ulr_offset - ulr->ulr_count), (void *)&ep, &bp, true)) != 0)
1046: return (error);
1047:
1.3 dholland 1048: #ifdef LFS_DIRHASH
1.1 dholland 1049: /*
1050: * Remove the dirhash entry. This is complicated by the fact
1051: * that `ep' is the previous entry when ulr_count != 0.
1052: */
1053: if (dp->i_dirhash != NULL)
1.4 dholland 1054: ulfsdirhash_remove(dp, (ulr->ulr_count == 0) ? ep :
1.7 dholland 1055: (struct lfs_direct *)((char *)ep +
1.4 dholland 1056: ulfs_rw16(ep->d_reclen, needswap)), ulr->ulr_offset);
1.1 dholland 1057: #endif
1058:
1059: if (ulr->ulr_count == 0) {
1060: /*
1061: * First entry in block: set d_ino to zero.
1062: */
1063: ep->d_ino = 0;
1064: } else {
1065: /*
1066: * Collapse new free space into previous entry.
1067: */
1068: ep->d_reclen =
1.4 dholland 1069: ulfs_rw16(ulfs_rw16(ep->d_reclen, needswap) + ulr->ulr_reclen,
1.1 dholland 1070: needswap);
1071: }
1072:
1.3 dholland 1073: #ifdef LFS_DIRHASH
1.1 dholland 1074: if (dp->i_dirhash != NULL) {
1.15 dholland 1075: int dirblksiz = ip->i_lfs->um_dirblksiz;
1.4 dholland 1076: ulfsdirhash_checkblock(dp, (char *)ep -
1.1 dholland 1077: ((ulr->ulr_offset - ulr->ulr_count) & (dirblksiz - 1)),
1078: ulr->ulr_offset & ~(dirblksiz - 1));
1079: }
1080: #endif
1081:
1082: out:
1083: if (ip) {
1084: ip->i_nlink--;
1085: DIP_ASSIGN(ip, nlink, ip->i_nlink);
1086: ip->i_flag |= IN_CHANGE;
1087: }
1088: /*
1089: * XXX did it ever occur to anyone that it might be a good
1090: * idea to restore ip->i_nlink if this fails? Or something?
1091: * Currently on error return from this function the state of
1092: * ip->i_nlink depends on what happened, and callers
1093: * definitely do not take this into account.
1094: */
1095: error = VOP_BWRITE(bp->b_vp, bp);
1096: dp->i_flag |= IN_CHANGE | IN_UPDATE;
1097: /*
1098: * If the last named reference to a snapshot goes away,
1099: * drop its snapshot reference so that it will be reclaimed
1100: * when last open reference goes away.
1101: */
1102: if (ip != 0 && (ip->i_flags & SF_SNAPSHOT) != 0 &&
1103: ip->i_nlink == 0)
1.6 dholland 1104: ulfs_snapgone(ip);
1.1 dholland 1105: return (error);
1106: }
1107:
1108: /*
1109: * Rewrite an existing directory entry to point at the inode supplied.
1110: *
1111: * DP is the directory to update.
1112: * OFFSET is the position of the entry in question. It may come
1.4 dholland 1113: * from ulr_offset of a ulfs_lookup_results.
1.1 dholland 1114: * OIP is the old inode the directory previously pointed to.
1115: * NEWINUM is the number of the new inode.
1116: * NEWTYPE is the new value for the type field of the directory entry.
1117: * (This is ignored if the fs doesn't support that.)
1118: * ISRMDIR is not used and (XXX) should be removed.
1119: * IFLAGS are added to DP's inode flags.
1120: *
1121: * The link count of OIP is decremented. Note that the link count of
1122: * the new inode is *not* incremented. Yay for symmetry.
1123: */
1124: int
1.4 dholland 1125: ulfs_dirrewrite(struct inode *dp, off_t offset,
1.1 dholland 1126: struct inode *oip, ino_t newinum, int newtype,
1127: int isrmdir, int iflags)
1128: {
1129: struct buf *bp;
1.7 dholland 1130: struct lfs_direct *ep;
1.1 dholland 1131: struct vnode *vdp = ITOV(dp);
1132: int error;
1133:
1.4 dholland 1134: error = ulfs_blkatoff(vdp, offset, (void *)&ep, &bp, true);
1.1 dholland 1135: if (error)
1136: return (error);
1.15 dholland 1137: ep->d_ino = ulfs_rw32(newinum, ULFS_IPNEEDSWAP(dp));
1.1 dholland 1138: if (!FSFMT(vdp))
1139: ep->d_type = newtype;
1140: oip->i_nlink--;
1141: DIP_ASSIGN(oip, nlink, oip->i_nlink);
1142: oip->i_flag |= IN_CHANGE;
1143: error = VOP_BWRITE(bp->b_vp, bp);
1144: dp->i_flag |= iflags;
1145: /*
1146: * If the last named reference to a snapshot goes away,
1147: * drop its snapshot reference so that it will be reclaimed
1148: * when last open reference goes away.
1149: */
1150: if ((oip->i_flags & SF_SNAPSHOT) != 0 && oip->i_nlink == 0)
1.6 dholland 1151: ulfs_snapgone(oip);
1.1 dholland 1152: return (error);
1153: }
1154:
1155: /*
1156: * Check if a directory is empty or not.
1157: * Inode supplied must be locked.
1158: *
1.7 dholland 1159: * Using a struct lfs_dirtemplate here is not precisely
1160: * what we want, but better than using a struct lfs_direct.
1.1 dholland 1161: *
1162: * NB: does not handle corrupted directories.
1163: */
1164: int
1.4 dholland 1165: ulfs_dirempty(struct inode *ip, ino_t parentino, kauth_cred_t cred)
1.1 dholland 1166: {
1167: doff_t off;
1.7 dholland 1168: struct lfs_dirtemplate dbuf;
1169: struct lfs_direct *dp = (struct lfs_direct *)&dbuf;
1.1 dholland 1170: int error, namlen;
1171: size_t count;
1.4 dholland 1172: const int needswap = ULFS_IPNEEDSWAP(ip);
1.7 dholland 1173: #define MINDIRSIZ (sizeof (struct lfs_dirtemplate) / 2)
1.1 dholland 1174:
1175: for (off = 0; off < ip->i_size;
1.4 dholland 1176: off += ulfs_rw16(dp->d_reclen, needswap)) {
1.22 riastrad 1177: error = ulfs_bufio(UIO_READ, ITOV(ip), (void *)dp, MINDIRSIZ,
1178: off, IO_NODELOCKED, cred, &count, NULL);
1.1 dholland 1179: /*
1180: * Since we read MINDIRSIZ, residual must
1181: * be 0 unless we're at end of file.
1182: */
1183: if (error || count != 0)
1184: return (0);
1185: /* avoid infinite loops */
1186: if (dp->d_reclen == 0)
1187: return (0);
1188: /* skip empty entries */
1.4 dholland 1189: if (dp->d_ino == 0 || ulfs_rw32(dp->d_ino, needswap) == ULFS_WINO)
1.1 dholland 1190: continue;
1191: /* accept only "." and ".." */
1192: #if (BYTE_ORDER == LITTLE_ENDIAN)
1193: if (FSFMT(ITOV(ip)) && needswap == 0)
1194: namlen = dp->d_type;
1195: else
1196: namlen = dp->d_namlen;
1197: #else
1198: if (FSFMT(ITOV(ip)) && needswap != 0)
1199: namlen = dp->d_type;
1200: else
1201: namlen = dp->d_namlen;
1202: #endif
1203: if (namlen > 2)
1204: return (0);
1205: if (dp->d_name[0] != '.')
1206: return (0);
1207: /*
1208: * At this point namlen must be 1 or 2.
1209: * 1 implies ".", 2 implies ".." if second
1210: * char is also "."
1211: */
1212: if (namlen == 1 &&
1.4 dholland 1213: ulfs_rw32(dp->d_ino, needswap) == ip->i_number)
1.1 dholland 1214: continue;
1215: if (dp->d_name[1] == '.' &&
1.4 dholland 1216: ulfs_rw32(dp->d_ino, needswap) == parentino)
1.1 dholland 1217: continue;
1218: return (0);
1219: }
1220: return (1);
1221: }
1222:
1.4 dholland 1223: #define ULFS_DIRRABLKS 0
1224: int ulfs_dirrablks = ULFS_DIRRABLKS;
1.1 dholland 1225:
1226: /*
1.4 dholland 1227: * ulfs_blkatoff: Return buffer with the contents of block "offset" from
1.1 dholland 1228: * the beginning of directory "vp". If "res" is non-NULL, fill it in with
1229: * a pointer to the remaining space in the directory. If the caller intends
1230: * to modify the buffer returned, "modify" must be true.
1231: */
1232:
1233: int
1.4 dholland 1234: ulfs_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp,
1.1 dholland 1235: bool modify)
1236: {
1.17 martin 1237: struct inode *ip __diagused;
1.1 dholland 1238: struct buf *bp;
1239: daddr_t lbn;
1.4 dholland 1240: const int dirrablks = ulfs_dirrablks;
1.1 dholland 1241: daddr_t *blks;
1242: int *blksizes;
1243: int run, error;
1244: struct mount *mp = vp->v_mount;
1245: const int bshift = mp->mnt_fs_bshift;
1246: const int bsize = 1 << bshift;
1247: off_t eof;
1248:
1249: blks = kmem_alloc((1 + dirrablks) * sizeof(daddr_t), KM_SLEEP);
1250: blksizes = kmem_alloc((1 + dirrablks) * sizeof(int), KM_SLEEP);
1251: ip = VTOI(vp);
1252: KASSERT(vp->v_size == ip->i_size);
1253: GOP_SIZE(vp, vp->v_size, &eof, 0);
1254: lbn = offset >> bshift;
1255:
1256: for (run = 0; run <= dirrablks;) {
1257: const off_t curoff = lbn << bshift;
1258: const int size = MIN(eof - curoff, bsize);
1259:
1260: if (size == 0) {
1261: break;
1262: }
1263: KASSERT(curoff < eof);
1264: blks[run] = lbn;
1265: blksizes[run] = size;
1266: lbn++;
1267: run++;
1268: if (size != bsize) {
1269: break;
1270: }
1271: }
1272: KASSERT(run >= 1);
1273: error = breadn(vp, blks[0], blksizes[0], &blks[1], &blksizes[1],
1.23 maxv 1274: run - 1, (modify ? B_MODIFY : 0), &bp);
1.1 dholland 1275: if (error != 0) {
1276: *bpp = NULL;
1277: goto out;
1278: }
1279: if (res) {
1280: *res = (char *)bp->b_data + (offset & (bsize - 1));
1281: }
1282: *bpp = bp;
1283:
1284: out:
1285: kmem_free(blks, (1 + dirrablks) * sizeof(daddr_t));
1286: kmem_free(blksizes, (1 + dirrablks) * sizeof(int));
1287: return error;
1288: }
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