xref: /netbsd-src/sys/ufs/ffs/ffs_alloc.c (revision 7a6a7ae08ac6c612f0fbb0d4425825c6be2a9050)
1 /*	$NetBSD: ffs_alloc.c,v 1.127 2011/03/06 17:08:38 bouyer Exp $	*/
2 
3 /*-
4  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Wasabi Systems, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 2002 Networks Associates Technology, Inc.
34  * All rights reserved.
35  *
36  * This software was developed for the FreeBSD Project by Marshall
37  * Kirk McKusick and Network Associates Laboratories, the Security
38  * Research Division of Network Associates, Inc. under DARPA/SPAWAR
39  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
40  * research program
41  *
42  * Copyright (c) 1982, 1986, 1989, 1993
43  *	The Regents of the University of California.  All rights reserved.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. Neither the name of the University nor the names of its contributors
54  *    may be used to endorse or promote products derived from this software
55  *    without specific prior written permission.
56  *
57  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
58  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
59  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
60  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
61  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
62  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
63  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
64  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
65  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
66  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67  * SUCH DAMAGE.
68  *
69  *	@(#)ffs_alloc.c	8.19 (Berkeley) 7/13/95
70  */
71 
72 #include <sys/cdefs.h>
73 __KERNEL_RCSID(0, "$NetBSD: ffs_alloc.c,v 1.127 2011/03/06 17:08:38 bouyer Exp $");
74 
75 #if defined(_KERNEL_OPT)
76 #include "opt_ffs.h"
77 #include "opt_quota.h"
78 #endif
79 
80 #include <sys/param.h>
81 #include <sys/systm.h>
82 #include <sys/buf.h>
83 #include <sys/fstrans.h>
84 #include <sys/kauth.h>
85 #include <sys/kernel.h>
86 #include <sys/mount.h>
87 #include <sys/proc.h>
88 #include <sys/syslog.h>
89 #include <sys/vnode.h>
90 #include <sys/wapbl.h>
91 
92 #include <miscfs/specfs/specdev.h>
93 #include <ufs/ufs/quota.h>
94 #include <ufs/ufs/ufsmount.h>
95 #include <ufs/ufs/inode.h>
96 #include <ufs/ufs/ufs_extern.h>
97 #include <ufs/ufs/ufs_bswap.h>
98 #include <ufs/ufs/ufs_wapbl.h>
99 
100 #include <ufs/ffs/fs.h>
101 #include <ufs/ffs/ffs_extern.h>
102 
103 static daddr_t ffs_alloccg(struct inode *, int, daddr_t, int, int);
104 static daddr_t ffs_alloccgblk(struct inode *, struct buf *, daddr_t, int);
105 static ino_t ffs_dirpref(struct inode *);
106 static daddr_t ffs_fragextend(struct inode *, int, daddr_t, int, int);
107 static void ffs_fserr(struct fs *, u_int, const char *);
108 static daddr_t ffs_hashalloc(struct inode *, int, daddr_t, int, int,
109     daddr_t (*)(struct inode *, int, daddr_t, int, int));
110 static daddr_t ffs_nodealloccg(struct inode *, int, daddr_t, int, int);
111 static int32_t ffs_mapsearch(struct fs *, struct cg *,
112 				      daddr_t, int);
113 static void ffs_blkfree_common(struct ufsmount *, struct fs *, dev_t, struct buf *,
114     daddr_t, long, bool);
115 static void ffs_freefile_common(struct ufsmount *, struct fs *, dev_t, struct buf *, ino_t,
116     int, bool);
117 
118 /* if 1, changes in optimalization strategy are logged */
119 int ffs_log_changeopt = 0;
120 
121 /* in ffs_tables.c */
122 extern const int inside[], around[];
123 extern const u_char * const fragtbl[];
124 
125 /* Basic consistency check for block allocations */
126 static int
127 ffs_check_bad_allocation(const char *func, struct fs *fs, daddr_t bno,
128     long size, dev_t dev, ino_t inum)
129 {
130 	if ((u_int)size > fs->fs_bsize || fragoff(fs, size) != 0 ||
131 	    fragnum(fs, bno) + numfrags(fs, size) > fs->fs_frag) {
132 		printf("dev = 0x%llx, bno = %" PRId64 " bsize = %d, "
133 		    "size = %ld, fs = %s\n",
134 		    (long long)dev, bno, fs->fs_bsize, size, fs->fs_fsmnt);
135 		panic("%s: bad size", func);
136 	}
137 
138 	if (bno >= fs->fs_size) {
139 		printf("bad block %" PRId64 ", ino %llu\n", bno,
140 		    (unsigned long long)inum);
141 		ffs_fserr(fs, inum, "bad block");
142 		return EINVAL;
143 	}
144 	return 0;
145 }
146 
147 /*
148  * Allocate a block in the file system.
149  *
150  * The size of the requested block is given, which must be some
151  * multiple of fs_fsize and <= fs_bsize.
152  * A preference may be optionally specified. If a preference is given
153  * the following hierarchy is used to allocate a block:
154  *   1) allocate the requested block.
155  *   2) allocate a rotationally optimal block in the same cylinder.
156  *   3) allocate a block in the same cylinder group.
157  *   4) quadradically rehash into other cylinder groups, until an
158  *      available block is located.
159  * If no block preference is given the following hierarchy is used
160  * to allocate a block:
161  *   1) allocate a block in the cylinder group that contains the
162  *      inode for the file.
163  *   2) quadradically rehash into other cylinder groups, until an
164  *      available block is located.
165  *
166  * => called with um_lock held
167  * => releases um_lock before returning
168  */
169 int
170 ffs_alloc(struct inode *ip, daddr_t lbn, daddr_t bpref, int size, int flags,
171     kauth_cred_t cred, daddr_t *bnp)
172 {
173 	struct ufsmount *ump;
174 	struct fs *fs;
175 	daddr_t bno;
176 	int cg;
177 #if defined(QUOTA) || defined(QUOTA2)
178 	int error;
179 #endif
180 
181 	fs = ip->i_fs;
182 	ump = ip->i_ump;
183 
184 	KASSERT(mutex_owned(&ump->um_lock));
185 
186 #ifdef UVM_PAGE_TRKOWN
187 	if (ITOV(ip)->v_type == VREG &&
188 	    lblktosize(fs, (voff_t)lbn) < round_page(ITOV(ip)->v_size)) {
189 		struct vm_page *pg;
190 		struct uvm_object *uobj = &ITOV(ip)->v_uobj;
191 		voff_t off = trunc_page(lblktosize(fs, lbn));
192 		voff_t endoff = round_page(lblktosize(fs, lbn) + size);
193 
194 		mutex_enter(&uobj->vmobjlock);
195 		while (off < endoff) {
196 			pg = uvm_pagelookup(uobj, off);
197 			KASSERT(pg == NULL || pg->owner == curproc->p_pid);
198 			off += PAGE_SIZE;
199 		}
200 		mutex_exit(&uobj->vmobjlock);
201 	}
202 #endif
203 
204 	*bnp = 0;
205 #ifdef DIAGNOSTIC
206 	if ((u_int)size > fs->fs_bsize || fragoff(fs, size) != 0) {
207 		printf("dev = 0x%llx, bsize = %d, size = %d, fs = %s\n",
208 		    (unsigned long long)ip->i_dev, fs->fs_bsize, size,
209 		    fs->fs_fsmnt);
210 		panic("ffs_alloc: bad size");
211 	}
212 	if (cred == NOCRED)
213 		panic("ffs_alloc: missing credential");
214 #endif /* DIAGNOSTIC */
215 	if (size == fs->fs_bsize && fs->fs_cstotal.cs_nbfree == 0)
216 		goto nospace;
217 	if (freespace(fs, fs->fs_minfree) <= 0 &&
218 	    kauth_authorize_system(cred, KAUTH_SYSTEM_FS_RESERVEDSPACE, 0, NULL,
219 	    NULL, NULL) != 0)
220 		goto nospace;
221 #if defined(QUOTA) || defined(QUOTA2)
222 	mutex_exit(&ump->um_lock);
223 	if ((error = chkdq(ip, btodb(size), cred, 0)) != 0)
224 		return (error);
225 	mutex_enter(&ump->um_lock);
226 #endif
227 
228 	if (bpref >= fs->fs_size)
229 		bpref = 0;
230 	if (bpref == 0)
231 		cg = ino_to_cg(fs, ip->i_number);
232 	else
233 		cg = dtog(fs, bpref);
234 	bno = ffs_hashalloc(ip, cg, bpref, size, flags, ffs_alloccg);
235 	if (bno > 0) {
236 		DIP_ADD(ip, blocks, btodb(size));
237 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
238 		*bnp = bno;
239 		return (0);
240 	}
241 #if defined(QUOTA) || defined(QUOTA2)
242 	/*
243 	 * Restore user's disk quota because allocation failed.
244 	 */
245 	(void) chkdq(ip, -btodb(size), cred, FORCE);
246 #endif
247 	if (flags & B_CONTIG) {
248 		/*
249 		 * XXX ump->um_lock handling is "suspect" at best.
250 		 * For the case where ffs_hashalloc() fails early
251 		 * in the B_CONTIG case we reach here with um_lock
252 		 * already unlocked, so we can't release it again
253 		 * like in the normal error path.  See kern/39206.
254 		 *
255 		 *
256 		 * Fail silently - it's up to our caller to report
257 		 * errors.
258 		 */
259 		return (ENOSPC);
260 	}
261 nospace:
262 	mutex_exit(&ump->um_lock);
263 	ffs_fserr(fs, kauth_cred_geteuid(cred), "file system full");
264 	uprintf("\n%s: write failed, file system is full\n", fs->fs_fsmnt);
265 	return (ENOSPC);
266 }
267 
268 /*
269  * Reallocate a fragment to a bigger size
270  *
271  * The number and size of the old block is given, and a preference
272  * and new size is also specified. The allocator attempts to extend
273  * the original block. Failing that, the regular block allocator is
274  * invoked to get an appropriate block.
275  *
276  * => called with um_lock held
277  * => return with um_lock released
278  */
279 int
280 ffs_realloccg(struct inode *ip, daddr_t lbprev, daddr_t bpref, int osize,
281     int nsize, kauth_cred_t cred, struct buf **bpp, daddr_t *blknop)
282 {
283 	struct ufsmount *ump;
284 	struct fs *fs;
285 	struct buf *bp;
286 	int cg, request, error;
287 	daddr_t bprev, bno;
288 
289 	fs = ip->i_fs;
290 	ump = ip->i_ump;
291 
292 	KASSERT(mutex_owned(&ump->um_lock));
293 
294 #ifdef UVM_PAGE_TRKOWN
295 	if (ITOV(ip)->v_type == VREG) {
296 		struct vm_page *pg;
297 		struct uvm_object *uobj = &ITOV(ip)->v_uobj;
298 		voff_t off = trunc_page(lblktosize(fs, lbprev));
299 		voff_t endoff = round_page(lblktosize(fs, lbprev) + osize);
300 
301 		mutex_enter(&uobj->vmobjlock);
302 		while (off < endoff) {
303 			pg = uvm_pagelookup(uobj, off);
304 			KASSERT(pg == NULL || pg->owner == curproc->p_pid);
305 			KASSERT((pg->flags & PG_CLEAN) == 0);
306 			off += PAGE_SIZE;
307 		}
308 		mutex_exit(&uobj->vmobjlock);
309 	}
310 #endif
311 
312 #ifdef DIAGNOSTIC
313 	if ((u_int)osize > fs->fs_bsize || fragoff(fs, osize) != 0 ||
314 	    (u_int)nsize > fs->fs_bsize || fragoff(fs, nsize) != 0) {
315 		printf(
316 		    "dev = 0x%llx, bsize = %d, osize = %d, nsize = %d, fs = %s\n",
317 		    (unsigned long long)ip->i_dev, fs->fs_bsize, osize, nsize,
318 		    fs->fs_fsmnt);
319 		panic("ffs_realloccg: bad size");
320 	}
321 	if (cred == NOCRED)
322 		panic("ffs_realloccg: missing credential");
323 #endif /* DIAGNOSTIC */
324 	if (freespace(fs, fs->fs_minfree) <= 0 &&
325 	    kauth_authorize_system(cred, KAUTH_SYSTEM_FS_RESERVEDSPACE, 0, NULL,
326 	    NULL, NULL) != 0) {
327 		mutex_exit(&ump->um_lock);
328 		goto nospace;
329 	}
330 	if (fs->fs_magic == FS_UFS2_MAGIC)
331 		bprev = ufs_rw64(ip->i_ffs2_db[lbprev], UFS_FSNEEDSWAP(fs));
332 	else
333 		bprev = ufs_rw32(ip->i_ffs1_db[lbprev], UFS_FSNEEDSWAP(fs));
334 
335 	if (bprev == 0) {
336 		printf("dev = 0x%llx, bsize = %d, bprev = %" PRId64 ", fs = %s\n",
337 		    (unsigned long long)ip->i_dev, fs->fs_bsize, bprev,
338 		    fs->fs_fsmnt);
339 		panic("ffs_realloccg: bad bprev");
340 	}
341 	mutex_exit(&ump->um_lock);
342 
343 	/*
344 	 * Allocate the extra space in the buffer.
345 	 */
346 	if (bpp != NULL &&
347 	    (error = bread(ITOV(ip), lbprev, osize, NOCRED, 0, &bp)) != 0) {
348 		brelse(bp, 0);
349 		return (error);
350 	}
351 #if defined(QUOTA) || defined(QUOTA2)
352 	if ((error = chkdq(ip, btodb(nsize - osize), cred, 0)) != 0) {
353 		if (bpp != NULL) {
354 			brelse(bp, 0);
355 		}
356 		return (error);
357 	}
358 #endif
359 	/*
360 	 * Check for extension in the existing location.
361 	 */
362 	cg = dtog(fs, bprev);
363 	mutex_enter(&ump->um_lock);
364 	if ((bno = ffs_fragextend(ip, cg, bprev, osize, nsize)) != 0) {
365 		DIP_ADD(ip, blocks, btodb(nsize - osize));
366 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
367 
368 		if (bpp != NULL) {
369 			if (bp->b_blkno != fsbtodb(fs, bno))
370 				panic("bad blockno");
371 			allocbuf(bp, nsize, 1);
372 			memset((char *)bp->b_data + osize, 0, nsize - osize);
373 			mutex_enter(bp->b_objlock);
374 			KASSERT(!cv_has_waiters(&bp->b_done));
375 			bp->b_oflags |= BO_DONE;
376 			mutex_exit(bp->b_objlock);
377 			*bpp = bp;
378 		}
379 		if (blknop != NULL) {
380 			*blknop = bno;
381 		}
382 		return (0);
383 	}
384 	/*
385 	 * Allocate a new disk location.
386 	 */
387 	if (bpref >= fs->fs_size)
388 		bpref = 0;
389 	switch ((int)fs->fs_optim) {
390 	case FS_OPTSPACE:
391 		/*
392 		 * Allocate an exact sized fragment. Although this makes
393 		 * best use of space, we will waste time relocating it if
394 		 * the file continues to grow. If the fragmentation is
395 		 * less than half of the minimum free reserve, we choose
396 		 * to begin optimizing for time.
397 		 */
398 		request = nsize;
399 		if (fs->fs_minfree < 5 ||
400 		    fs->fs_cstotal.cs_nffree >
401 		    fs->fs_dsize * fs->fs_minfree / (2 * 100))
402 			break;
403 
404 		if (ffs_log_changeopt) {
405 			log(LOG_NOTICE,
406 				"%s: optimization changed from SPACE to TIME\n",
407 				fs->fs_fsmnt);
408 		}
409 
410 		fs->fs_optim = FS_OPTTIME;
411 		break;
412 	case FS_OPTTIME:
413 		/*
414 		 * At this point we have discovered a file that is trying to
415 		 * grow a small fragment to a larger fragment. To save time,
416 		 * we allocate a full sized block, then free the unused portion.
417 		 * If the file continues to grow, the `ffs_fragextend' call
418 		 * above will be able to grow it in place without further
419 		 * copying. If aberrant programs cause disk fragmentation to
420 		 * grow within 2% of the free reserve, we choose to begin
421 		 * optimizing for space.
422 		 */
423 		request = fs->fs_bsize;
424 		if (fs->fs_cstotal.cs_nffree <
425 		    fs->fs_dsize * (fs->fs_minfree - 2) / 100)
426 			break;
427 
428 		if (ffs_log_changeopt) {
429 			log(LOG_NOTICE,
430 				"%s: optimization changed from TIME to SPACE\n",
431 				fs->fs_fsmnt);
432 		}
433 
434 		fs->fs_optim = FS_OPTSPACE;
435 		break;
436 	default:
437 		printf("dev = 0x%llx, optim = %d, fs = %s\n",
438 		    (unsigned long long)ip->i_dev, fs->fs_optim, fs->fs_fsmnt);
439 		panic("ffs_realloccg: bad optim");
440 		/* NOTREACHED */
441 	}
442 	bno = ffs_hashalloc(ip, cg, bpref, request, 0, ffs_alloccg);
443 	if (bno > 0) {
444 		if ((ip->i_ump->um_mountp->mnt_wapbl) &&
445 		    (ITOV(ip)->v_type != VREG)) {
446 			UFS_WAPBL_REGISTER_DEALLOCATION(
447 			    ip->i_ump->um_mountp, fsbtodb(fs, bprev),
448 			    osize);
449 		} else {
450 			ffs_blkfree(fs, ip->i_devvp, bprev, (long)osize,
451 			    ip->i_number);
452 		}
453 		if (nsize < request) {
454 			if ((ip->i_ump->um_mountp->mnt_wapbl) &&
455 			    (ITOV(ip)->v_type != VREG)) {
456 				UFS_WAPBL_REGISTER_DEALLOCATION(
457 				    ip->i_ump->um_mountp,
458 				    fsbtodb(fs, (bno + numfrags(fs, nsize))),
459 				    request - nsize);
460 			} else
461 				ffs_blkfree(fs, ip->i_devvp,
462 				    bno + numfrags(fs, nsize),
463 				    (long)(request - nsize), ip->i_number);
464 		}
465 		DIP_ADD(ip, blocks, btodb(nsize - osize));
466 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
467 		if (bpp != NULL) {
468 			bp->b_blkno = fsbtodb(fs, bno);
469 			allocbuf(bp, nsize, 1);
470 			memset((char *)bp->b_data + osize, 0, (u_int)nsize - osize);
471 			mutex_enter(bp->b_objlock);
472 			KASSERT(!cv_has_waiters(&bp->b_done));
473 			bp->b_oflags |= BO_DONE;
474 			mutex_exit(bp->b_objlock);
475 			*bpp = bp;
476 		}
477 		if (blknop != NULL) {
478 			*blknop = bno;
479 		}
480 		return (0);
481 	}
482 	mutex_exit(&ump->um_lock);
483 
484 #if defined(QUOTA) || defined(QUOTA2)
485 	/*
486 	 * Restore user's disk quota because allocation failed.
487 	 */
488 	(void) chkdq(ip, -btodb(nsize - osize), cred, FORCE);
489 #endif
490 	if (bpp != NULL) {
491 		brelse(bp, 0);
492 	}
493 
494 nospace:
495 	/*
496 	 * no space available
497 	 */
498 	ffs_fserr(fs, kauth_cred_geteuid(cred), "file system full");
499 	uprintf("\n%s: write failed, file system is full\n", fs->fs_fsmnt);
500 	return (ENOSPC);
501 }
502 
503 /*
504  * Allocate an inode in the file system.
505  *
506  * If allocating a directory, use ffs_dirpref to select the inode.
507  * If allocating in a directory, the following hierarchy is followed:
508  *   1) allocate the preferred inode.
509  *   2) allocate an inode in the same cylinder group.
510  *   3) quadradically rehash into other cylinder groups, until an
511  *      available inode is located.
512  * If no inode preference is given the following hierarchy is used
513  * to allocate an inode:
514  *   1) allocate an inode in cylinder group 0.
515  *   2) quadradically rehash into other cylinder groups, until an
516  *      available inode is located.
517  *
518  * => um_lock not held upon entry or return
519  */
520 int
521 ffs_valloc(struct vnode *pvp, int mode, kauth_cred_t cred,
522     struct vnode **vpp)
523 {
524 	struct ufsmount *ump;
525 	struct inode *pip;
526 	struct fs *fs;
527 	struct inode *ip;
528 	struct timespec ts;
529 	ino_t ino, ipref;
530 	int cg, error;
531 
532 	UFS_WAPBL_JUNLOCK_ASSERT(pvp->v_mount);
533 
534 	*vpp = NULL;
535 	pip = VTOI(pvp);
536 	fs = pip->i_fs;
537 	ump = pip->i_ump;
538 
539 	error = UFS_WAPBL_BEGIN(pvp->v_mount);
540 	if (error) {
541 		return error;
542 	}
543 	mutex_enter(&ump->um_lock);
544 	if (fs->fs_cstotal.cs_nifree == 0)
545 		goto noinodes;
546 
547 	if ((mode & IFMT) == IFDIR)
548 		ipref = ffs_dirpref(pip);
549 	else
550 		ipref = pip->i_number;
551 	if (ipref >= fs->fs_ncg * fs->fs_ipg)
552 		ipref = 0;
553 	cg = ino_to_cg(fs, ipref);
554 	/*
555 	 * Track number of dirs created one after another
556 	 * in a same cg without intervening by files.
557 	 */
558 	if ((mode & IFMT) == IFDIR) {
559 		if (fs->fs_contigdirs[cg] < 255)
560 			fs->fs_contigdirs[cg]++;
561 	} else {
562 		if (fs->fs_contigdirs[cg] > 0)
563 			fs->fs_contigdirs[cg]--;
564 	}
565 	ino = (ino_t)ffs_hashalloc(pip, cg, ipref, mode, 0, ffs_nodealloccg);
566 	if (ino == 0)
567 		goto noinodes;
568 	UFS_WAPBL_END(pvp->v_mount);
569 	error = VFS_VGET(pvp->v_mount, ino, vpp);
570 	if (error) {
571 		int err;
572 		err = UFS_WAPBL_BEGIN(pvp->v_mount);
573 		if (err == 0)
574 			ffs_vfree(pvp, ino, mode);
575 		if (err == 0)
576 			UFS_WAPBL_END(pvp->v_mount);
577 		return (error);
578 	}
579 	KASSERT((*vpp)->v_type == VNON);
580 	ip = VTOI(*vpp);
581 	if (ip->i_mode) {
582 #if 0
583 		printf("mode = 0%o, inum = %d, fs = %s\n",
584 		    ip->i_mode, ip->i_number, fs->fs_fsmnt);
585 #else
586 		printf("dmode %x mode %x dgen %x gen %x\n",
587 		    DIP(ip, mode), ip->i_mode,
588 		    DIP(ip, gen), ip->i_gen);
589 		printf("size %llx blocks %llx\n",
590 		    (long long)DIP(ip, size), (long long)DIP(ip, blocks));
591 		printf("ino %llu ipref %llu\n", (unsigned long long)ino,
592 		    (unsigned long long)ipref);
593 #if 0
594 		error = bread(ump->um_devvp, fsbtodb(fs, ino_to_fsba(fs, ino)),
595 		    (int)fs->fs_bsize, NOCRED, 0, &bp);
596 #endif
597 
598 #endif
599 		panic("ffs_valloc: dup alloc");
600 	}
601 	if (DIP(ip, blocks)) {				/* XXX */
602 		printf("free inode %s/%llu had %" PRId64 " blocks\n",
603 		    fs->fs_fsmnt, (unsigned long long)ino, DIP(ip, blocks));
604 		DIP_ASSIGN(ip, blocks, 0);
605 	}
606 	ip->i_flag &= ~IN_SPACECOUNTED;
607 	ip->i_flags = 0;
608 	DIP_ASSIGN(ip, flags, 0);
609 	/*
610 	 * Set up a new generation number for this inode.
611 	 */
612 	ip->i_gen++;
613 	DIP_ASSIGN(ip, gen, ip->i_gen);
614 	if (fs->fs_magic == FS_UFS2_MAGIC) {
615 		vfs_timestamp(&ts);
616 		ip->i_ffs2_birthtime = ts.tv_sec;
617 		ip->i_ffs2_birthnsec = ts.tv_nsec;
618 	}
619 	return (0);
620 noinodes:
621 	mutex_exit(&ump->um_lock);
622 	UFS_WAPBL_END(pvp->v_mount);
623 	ffs_fserr(fs, kauth_cred_geteuid(cred), "out of inodes");
624 	uprintf("\n%s: create/symlink failed, no inodes free\n", fs->fs_fsmnt);
625 	return (ENOSPC);
626 }
627 
628 /*
629  * Find a cylinder group in which to place a directory.
630  *
631  * The policy implemented by this algorithm is to allocate a
632  * directory inode in the same cylinder group as its parent
633  * directory, but also to reserve space for its files inodes
634  * and data. Restrict the number of directories which may be
635  * allocated one after another in the same cylinder group
636  * without intervening allocation of files.
637  *
638  * If we allocate a first level directory then force allocation
639  * in another cylinder group.
640  */
641 static ino_t
642 ffs_dirpref(struct inode *pip)
643 {
644 	register struct fs *fs;
645 	int cg, prefcg;
646 	int64_t dirsize, cgsize, curdsz;
647 	int avgifree, avgbfree, avgndir;
648 	int minifree, minbfree, maxndir;
649 	int mincg, minndir;
650 	int maxcontigdirs;
651 
652 	KASSERT(mutex_owned(&pip->i_ump->um_lock));
653 
654 	fs = pip->i_fs;
655 
656 	avgifree = fs->fs_cstotal.cs_nifree / fs->fs_ncg;
657 	avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
658 	avgndir = fs->fs_cstotal.cs_ndir / fs->fs_ncg;
659 
660 	/*
661 	 * Force allocation in another cg if creating a first level dir.
662 	 */
663 	if (ITOV(pip)->v_vflag & VV_ROOT) {
664 		prefcg = random() % fs->fs_ncg;
665 		mincg = prefcg;
666 		minndir = fs->fs_ipg;
667 		for (cg = prefcg; cg < fs->fs_ncg; cg++)
668 			if (fs->fs_cs(fs, cg).cs_ndir < minndir &&
669 			    fs->fs_cs(fs, cg).cs_nifree >= avgifree &&
670 			    fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
671 				mincg = cg;
672 				minndir = fs->fs_cs(fs, cg).cs_ndir;
673 			}
674 		for (cg = 0; cg < prefcg; cg++)
675 			if (fs->fs_cs(fs, cg).cs_ndir < minndir &&
676 			    fs->fs_cs(fs, cg).cs_nifree >= avgifree &&
677 			    fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
678 				mincg = cg;
679 				minndir = fs->fs_cs(fs, cg).cs_ndir;
680 			}
681 		return ((ino_t)(fs->fs_ipg * mincg));
682 	}
683 
684 	/*
685 	 * Count various limits which used for
686 	 * optimal allocation of a directory inode.
687 	 */
688 	maxndir = min(avgndir + fs->fs_ipg / 16, fs->fs_ipg);
689 	minifree = avgifree - fs->fs_ipg / 4;
690 	if (minifree < 0)
691 		minifree = 0;
692 	minbfree = avgbfree - fragstoblks(fs, fs->fs_fpg) / 4;
693 	if (minbfree < 0)
694 		minbfree = 0;
695 	cgsize = (int64_t)fs->fs_fsize * fs->fs_fpg;
696 	dirsize = (int64_t)fs->fs_avgfilesize * fs->fs_avgfpdir;
697 	if (avgndir != 0) {
698 		curdsz = (cgsize - (int64_t)avgbfree * fs->fs_bsize) / avgndir;
699 		if (dirsize < curdsz)
700 			dirsize = curdsz;
701 	}
702 	if (cgsize < dirsize * 255)
703 		maxcontigdirs = cgsize / dirsize;
704 	else
705 		maxcontigdirs = 255;
706 	if (fs->fs_avgfpdir > 0)
707 		maxcontigdirs = min(maxcontigdirs,
708 				    fs->fs_ipg / fs->fs_avgfpdir);
709 	if (maxcontigdirs == 0)
710 		maxcontigdirs = 1;
711 
712 	/*
713 	 * Limit number of dirs in one cg and reserve space for
714 	 * regular files, but only if we have no deficit in
715 	 * inodes or space.
716 	 */
717 	prefcg = ino_to_cg(fs, pip->i_number);
718 	for (cg = prefcg; cg < fs->fs_ncg; cg++)
719 		if (fs->fs_cs(fs, cg).cs_ndir < maxndir &&
720 		    fs->fs_cs(fs, cg).cs_nifree >= minifree &&
721 	    	    fs->fs_cs(fs, cg).cs_nbfree >= minbfree) {
722 			if (fs->fs_contigdirs[cg] < maxcontigdirs)
723 				return ((ino_t)(fs->fs_ipg * cg));
724 		}
725 	for (cg = 0; cg < prefcg; cg++)
726 		if (fs->fs_cs(fs, cg).cs_ndir < maxndir &&
727 		    fs->fs_cs(fs, cg).cs_nifree >= minifree &&
728 	    	    fs->fs_cs(fs, cg).cs_nbfree >= minbfree) {
729 			if (fs->fs_contigdirs[cg] < maxcontigdirs)
730 				return ((ino_t)(fs->fs_ipg * cg));
731 		}
732 	/*
733 	 * This is a backstop when we are deficient in space.
734 	 */
735 	for (cg = prefcg; cg < fs->fs_ncg; cg++)
736 		if (fs->fs_cs(fs, cg).cs_nifree >= avgifree)
737 			return ((ino_t)(fs->fs_ipg * cg));
738 	for (cg = 0; cg < prefcg; cg++)
739 		if (fs->fs_cs(fs, cg).cs_nifree >= avgifree)
740 			break;
741 	return ((ino_t)(fs->fs_ipg * cg));
742 }
743 
744 /*
745  * Select the desired position for the next block in a file.  The file is
746  * logically divided into sections. The first section is composed of the
747  * direct blocks. Each additional section contains fs_maxbpg blocks.
748  *
749  * If no blocks have been allocated in the first section, the policy is to
750  * request a block in the same cylinder group as the inode that describes
751  * the file. If no blocks have been allocated in any other section, the
752  * policy is to place the section in a cylinder group with a greater than
753  * average number of free blocks.  An appropriate cylinder group is found
754  * by using a rotor that sweeps the cylinder groups. When a new group of
755  * blocks is needed, the sweep begins in the cylinder group following the
756  * cylinder group from which the previous allocation was made. The sweep
757  * continues until a cylinder group with greater than the average number
758  * of free blocks is found. If the allocation is for the first block in an
759  * indirect block, the information on the previous allocation is unavailable;
760  * here a best guess is made based upon the logical block number being
761  * allocated.
762  *
763  * If a section is already partially allocated, the policy is to
764  * contiguously allocate fs_maxcontig blocks.  The end of one of these
765  * contiguous blocks and the beginning of the next is laid out
766  * contigously if possible.
767  *
768  * => um_lock held on entry and exit
769  */
770 daddr_t
771 ffs_blkpref_ufs1(struct inode *ip, daddr_t lbn, int indx, int flags,
772     int32_t *bap /* XXX ondisk32 */)
773 {
774 	struct fs *fs;
775 	int cg;
776 	int avgbfree, startcg;
777 
778 	KASSERT(mutex_owned(&ip->i_ump->um_lock));
779 
780 	fs = ip->i_fs;
781 
782 	/*
783 	 * If allocating a contiguous file with B_CONTIG, use the hints
784 	 * in the inode extentions to return the desired block.
785 	 *
786 	 * For metadata (indirect blocks) return the address of where
787 	 * the first indirect block resides - we'll scan for the next
788 	 * available slot if we need to allocate more than one indirect
789 	 * block.  For data, return the address of the actual block
790 	 * relative to the address of the first data block.
791 	 */
792 	if (flags & B_CONTIG) {
793 		KASSERT(ip->i_ffs_first_data_blk != 0);
794 		KASSERT(ip->i_ffs_first_indir_blk != 0);
795 		if (flags & B_METAONLY)
796 			return ip->i_ffs_first_indir_blk;
797 		else
798 			return ip->i_ffs_first_data_blk + blkstofrags(fs, lbn);
799 	}
800 
801 	if (indx % fs->fs_maxbpg == 0 || bap[indx - 1] == 0) {
802 		if (lbn < NDADDR + NINDIR(fs)) {
803 			cg = ino_to_cg(fs, ip->i_number);
804 			return (cgbase(fs, cg) + fs->fs_frag);
805 		}
806 		/*
807 		 * Find a cylinder with greater than average number of
808 		 * unused data blocks.
809 		 */
810 		if (indx == 0 || bap[indx - 1] == 0)
811 			startcg =
812 			    ino_to_cg(fs, ip->i_number) + lbn / fs->fs_maxbpg;
813 		else
814 			startcg = dtog(fs,
815 				ufs_rw32(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + 1);
816 		startcg %= fs->fs_ncg;
817 		avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
818 		for (cg = startcg; cg < fs->fs_ncg; cg++)
819 			if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
820 				return (cgbase(fs, cg) + fs->fs_frag);
821 			}
822 		for (cg = 0; cg < startcg; cg++)
823 			if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
824 				return (cgbase(fs, cg) + fs->fs_frag);
825 			}
826 		return (0);
827 	}
828 	/*
829 	 * We just always try to lay things out contiguously.
830 	 */
831 	return ufs_rw32(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + fs->fs_frag;
832 }
833 
834 daddr_t
835 ffs_blkpref_ufs2(struct inode *ip, daddr_t lbn, int indx, int flags,
836     int64_t *bap)
837 {
838 	struct fs *fs;
839 	int cg;
840 	int avgbfree, startcg;
841 
842 	KASSERT(mutex_owned(&ip->i_ump->um_lock));
843 
844 	fs = ip->i_fs;
845 
846 	/*
847 	 * If allocating a contiguous file with B_CONTIG, use the hints
848 	 * in the inode extentions to return the desired block.
849 	 *
850 	 * For metadata (indirect blocks) return the address of where
851 	 * the first indirect block resides - we'll scan for the next
852 	 * available slot if we need to allocate more than one indirect
853 	 * block.  For data, return the address of the actual block
854 	 * relative to the address of the first data block.
855 	 */
856 	if (flags & B_CONTIG) {
857 		KASSERT(ip->i_ffs_first_data_blk != 0);
858 		KASSERT(ip->i_ffs_first_indir_blk != 0);
859 		if (flags & B_METAONLY)
860 			return ip->i_ffs_first_indir_blk;
861 		else
862 			return ip->i_ffs_first_data_blk + blkstofrags(fs, lbn);
863 	}
864 
865 	if (indx % fs->fs_maxbpg == 0 || bap[indx - 1] == 0) {
866 		if (lbn < NDADDR + NINDIR(fs)) {
867 			cg = ino_to_cg(fs, ip->i_number);
868 			return (cgbase(fs, cg) + fs->fs_frag);
869 		}
870 		/*
871 		 * Find a cylinder with greater than average number of
872 		 * unused data blocks.
873 		 */
874 		if (indx == 0 || bap[indx - 1] == 0)
875 			startcg =
876 			    ino_to_cg(fs, ip->i_number) + lbn / fs->fs_maxbpg;
877 		else
878 			startcg = dtog(fs,
879 				ufs_rw64(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + 1);
880 		startcg %= fs->fs_ncg;
881 		avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
882 		for (cg = startcg; cg < fs->fs_ncg; cg++)
883 			if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
884 				return (cgbase(fs, cg) + fs->fs_frag);
885 			}
886 		for (cg = 0; cg < startcg; cg++)
887 			if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
888 				return (cgbase(fs, cg) + fs->fs_frag);
889 			}
890 		return (0);
891 	}
892 	/*
893 	 * We just always try to lay things out contiguously.
894 	 */
895 	return ufs_rw64(bap[indx - 1], UFS_FSNEEDSWAP(fs)) + fs->fs_frag;
896 }
897 
898 
899 /*
900  * Implement the cylinder overflow algorithm.
901  *
902  * The policy implemented by this algorithm is:
903  *   1) allocate the block in its requested cylinder group.
904  *   2) quadradically rehash on the cylinder group number.
905  *   3) brute force search for a free block.
906  *
907  * => called with um_lock held
908  * => returns with um_lock released on success, held on failure
909  *    (*allocator releases lock on success, retains lock on failure)
910  */
911 /*VARARGS5*/
912 static daddr_t
913 ffs_hashalloc(struct inode *ip, int cg, daddr_t pref,
914     int size /* size for data blocks, mode for inodes */,
915     int flags, daddr_t (*allocator)(struct inode *, int, daddr_t, int, int))
916 {
917 	struct fs *fs;
918 	daddr_t result;
919 	int i, icg = cg;
920 
921 	fs = ip->i_fs;
922 	/*
923 	 * 1: preferred cylinder group
924 	 */
925 	result = (*allocator)(ip, cg, pref, size, flags);
926 	if (result)
927 		return (result);
928 
929 	if (flags & B_CONTIG)
930 		return (result);
931 	/*
932 	 * 2: quadratic rehash
933 	 */
934 	for (i = 1; i < fs->fs_ncg; i *= 2) {
935 		cg += i;
936 		if (cg >= fs->fs_ncg)
937 			cg -= fs->fs_ncg;
938 		result = (*allocator)(ip, cg, 0, size, flags);
939 		if (result)
940 			return (result);
941 	}
942 	/*
943 	 * 3: brute force search
944 	 * Note that we start at i == 2, since 0 was checked initially,
945 	 * and 1 is always checked in the quadratic rehash.
946 	 */
947 	cg = (icg + 2) % fs->fs_ncg;
948 	for (i = 2; i < fs->fs_ncg; i++) {
949 		result = (*allocator)(ip, cg, 0, size, flags);
950 		if (result)
951 			return (result);
952 		cg++;
953 		if (cg == fs->fs_ncg)
954 			cg = 0;
955 	}
956 	return (0);
957 }
958 
959 /*
960  * Determine whether a fragment can be extended.
961  *
962  * Check to see if the necessary fragments are available, and
963  * if they are, allocate them.
964  *
965  * => called with um_lock held
966  * => returns with um_lock released on success, held on failure
967  */
968 static daddr_t
969 ffs_fragextend(struct inode *ip, int cg, daddr_t bprev, int osize, int nsize)
970 {
971 	struct ufsmount *ump;
972 	struct fs *fs;
973 	struct cg *cgp;
974 	struct buf *bp;
975 	daddr_t bno;
976 	int frags, bbase;
977 	int i, error;
978 	u_int8_t *blksfree;
979 
980 	fs = ip->i_fs;
981 	ump = ip->i_ump;
982 
983 	KASSERT(mutex_owned(&ump->um_lock));
984 
985 	if (fs->fs_cs(fs, cg).cs_nffree < numfrags(fs, nsize - osize))
986 		return (0);
987 	frags = numfrags(fs, nsize);
988 	bbase = fragnum(fs, bprev);
989 	if (bbase > fragnum(fs, (bprev + frags - 1))) {
990 		/* cannot extend across a block boundary */
991 		return (0);
992 	}
993 	mutex_exit(&ump->um_lock);
994 	error = bread(ip->i_devvp, fsbtodb(fs, cgtod(fs, cg)),
995 		(int)fs->fs_cgsize, NOCRED, B_MODIFY, &bp);
996 	if (error)
997 		goto fail;
998 	cgp = (struct cg *)bp->b_data;
999 	if (!cg_chkmagic(cgp, UFS_FSNEEDSWAP(fs)))
1000 		goto fail;
1001 	cgp->cg_old_time = ufs_rw32(time_second, UFS_FSNEEDSWAP(fs));
1002 	if ((fs->fs_magic != FS_UFS1_MAGIC) ||
1003 	    (fs->fs_old_flags & FS_FLAGS_UPDATED))
1004 		cgp->cg_time = ufs_rw64(time_second, UFS_FSNEEDSWAP(fs));
1005 	bno = dtogd(fs, bprev);
1006 	blksfree = cg_blksfree(cgp, UFS_FSNEEDSWAP(fs));
1007 	for (i = numfrags(fs, osize); i < frags; i++)
1008 		if (isclr(blksfree, bno + i))
1009 			goto fail;
1010 	/*
1011 	 * the current fragment can be extended
1012 	 * deduct the count on fragment being extended into
1013 	 * increase the count on the remaining fragment (if any)
1014 	 * allocate the extended piece
1015 	 */
1016 	for (i = frags; i < fs->fs_frag - bbase; i++)
1017 		if (isclr(blksfree, bno + i))
1018 			break;
1019 	ufs_add32(cgp->cg_frsum[i - numfrags(fs, osize)], -1, UFS_FSNEEDSWAP(fs));
1020 	if (i != frags)
1021 		ufs_add32(cgp->cg_frsum[i - frags], 1, UFS_FSNEEDSWAP(fs));
1022 	mutex_enter(&ump->um_lock);
1023 	for (i = numfrags(fs, osize); i < frags; i++) {
1024 		clrbit(blksfree, bno + i);
1025 		ufs_add32(cgp->cg_cs.cs_nffree, -1, UFS_FSNEEDSWAP(fs));
1026 		fs->fs_cstotal.cs_nffree--;
1027 		fs->fs_cs(fs, cg).cs_nffree--;
1028 	}
1029 	fs->fs_fmod = 1;
1030 	ACTIVECG_CLR(fs, cg);
1031 	mutex_exit(&ump->um_lock);
1032 	bdwrite(bp);
1033 	return (bprev);
1034 
1035  fail:
1036  	brelse(bp, 0);
1037  	mutex_enter(&ump->um_lock);
1038  	return (0);
1039 }
1040 
1041 /*
1042  * Determine whether a block can be allocated.
1043  *
1044  * Check to see if a block of the appropriate size is available,
1045  * and if it is, allocate it.
1046  */
1047 static daddr_t
1048 ffs_alloccg(struct inode *ip, int cg, daddr_t bpref, int size, int flags)
1049 {
1050 	struct ufsmount *ump;
1051 	struct fs *fs = ip->i_fs;
1052 	struct cg *cgp;
1053 	struct buf *bp;
1054 	int32_t bno;
1055 	daddr_t blkno;
1056 	int error, frags, allocsiz, i;
1057 	u_int8_t *blksfree;
1058 #ifdef FFS_EI
1059 	const int needswap = UFS_FSNEEDSWAP(fs);
1060 #endif
1061 
1062 	ump = ip->i_ump;
1063 
1064 	KASSERT(mutex_owned(&ump->um_lock));
1065 
1066 	if (fs->fs_cs(fs, cg).cs_nbfree == 0 && size == fs->fs_bsize)
1067 		return (0);
1068 	mutex_exit(&ump->um_lock);
1069 	error = bread(ip->i_devvp, fsbtodb(fs, cgtod(fs, cg)),
1070 		(int)fs->fs_cgsize, NOCRED, B_MODIFY, &bp);
1071 	if (error)
1072 		goto fail;
1073 	cgp = (struct cg *)bp->b_data;
1074 	if (!cg_chkmagic(cgp, needswap) ||
1075 	    (cgp->cg_cs.cs_nbfree == 0 && size == fs->fs_bsize))
1076 		goto fail;
1077 	cgp->cg_old_time = ufs_rw32(time_second, needswap);
1078 	if ((fs->fs_magic != FS_UFS1_MAGIC) ||
1079 	    (fs->fs_old_flags & FS_FLAGS_UPDATED))
1080 		cgp->cg_time = ufs_rw64(time_second, needswap);
1081 	if (size == fs->fs_bsize) {
1082 		mutex_enter(&ump->um_lock);
1083 		blkno = ffs_alloccgblk(ip, bp, bpref, flags);
1084 		ACTIVECG_CLR(fs, cg);
1085 		mutex_exit(&ump->um_lock);
1086 		bdwrite(bp);
1087 		return (blkno);
1088 	}
1089 	/*
1090 	 * check to see if any fragments are already available
1091 	 * allocsiz is the size which will be allocated, hacking
1092 	 * it down to a smaller size if necessary
1093 	 */
1094 	blksfree = cg_blksfree(cgp, needswap);
1095 	frags = numfrags(fs, size);
1096 	for (allocsiz = frags; allocsiz < fs->fs_frag; allocsiz++)
1097 		if (cgp->cg_frsum[allocsiz] != 0)
1098 			break;
1099 	if (allocsiz == fs->fs_frag) {
1100 		/*
1101 		 * no fragments were available, so a block will be
1102 		 * allocated, and hacked up
1103 		 */
1104 		if (cgp->cg_cs.cs_nbfree == 0)
1105 			goto fail;
1106 		mutex_enter(&ump->um_lock);
1107 		blkno = ffs_alloccgblk(ip, bp, bpref, flags);
1108 		bno = dtogd(fs, blkno);
1109 		for (i = frags; i < fs->fs_frag; i++)
1110 			setbit(blksfree, bno + i);
1111 		i = fs->fs_frag - frags;
1112 		ufs_add32(cgp->cg_cs.cs_nffree, i, needswap);
1113 		fs->fs_cstotal.cs_nffree += i;
1114 		fs->fs_cs(fs, cg).cs_nffree += i;
1115 		fs->fs_fmod = 1;
1116 		ufs_add32(cgp->cg_frsum[i], 1, needswap);
1117 		ACTIVECG_CLR(fs, cg);
1118 		mutex_exit(&ump->um_lock);
1119 		bdwrite(bp);
1120 		return (blkno);
1121 	}
1122 	bno = ffs_mapsearch(fs, cgp, bpref, allocsiz);
1123 #if 0
1124 	/*
1125 	 * XXX fvdl mapsearch will panic, and never return -1
1126 	 *          also: returning NULL as daddr_t ?
1127 	 */
1128 	if (bno < 0)
1129 		goto fail;
1130 #endif
1131 	for (i = 0; i < frags; i++)
1132 		clrbit(blksfree, bno + i);
1133 	mutex_enter(&ump->um_lock);
1134 	ufs_add32(cgp->cg_cs.cs_nffree, -frags, needswap);
1135 	fs->fs_cstotal.cs_nffree -= frags;
1136 	fs->fs_cs(fs, cg).cs_nffree -= frags;
1137 	fs->fs_fmod = 1;
1138 	ufs_add32(cgp->cg_frsum[allocsiz], -1, needswap);
1139 	if (frags != allocsiz)
1140 		ufs_add32(cgp->cg_frsum[allocsiz - frags], 1, needswap);
1141 	blkno = cgbase(fs, cg) + bno;
1142 	ACTIVECG_CLR(fs, cg);
1143 	mutex_exit(&ump->um_lock);
1144 	bdwrite(bp);
1145 	return blkno;
1146 
1147  fail:
1148  	brelse(bp, 0);
1149  	mutex_enter(&ump->um_lock);
1150  	return (0);
1151 }
1152 
1153 /*
1154  * Allocate a block in a cylinder group.
1155  *
1156  * This algorithm implements the following policy:
1157  *   1) allocate the requested block.
1158  *   2) allocate a rotationally optimal block in the same cylinder.
1159  *   3) allocate the next available block on the block rotor for the
1160  *      specified cylinder group.
1161  * Note that this routine only allocates fs_bsize blocks; these
1162  * blocks may be fragmented by the routine that allocates them.
1163  */
1164 static daddr_t
1165 ffs_alloccgblk(struct inode *ip, struct buf *bp, daddr_t bpref, int flags)
1166 {
1167 	struct ufsmount *ump;
1168 	struct fs *fs = ip->i_fs;
1169 	struct cg *cgp;
1170 	int cg;
1171 	daddr_t blkno;
1172 	int32_t bno;
1173 	u_int8_t *blksfree;
1174 #ifdef FFS_EI
1175 	const int needswap = UFS_FSNEEDSWAP(fs);
1176 #endif
1177 
1178 	ump = ip->i_ump;
1179 
1180 	KASSERT(mutex_owned(&ump->um_lock));
1181 
1182 	cgp = (struct cg *)bp->b_data;
1183 	blksfree = cg_blksfree(cgp, needswap);
1184 	if (bpref == 0 || dtog(fs, bpref) != ufs_rw32(cgp->cg_cgx, needswap)) {
1185 		bpref = ufs_rw32(cgp->cg_rotor, needswap);
1186 	} else {
1187 		bpref = blknum(fs, bpref);
1188 		bno = dtogd(fs, bpref);
1189 		/*
1190 		 * if the requested block is available, use it
1191 		 */
1192 		if (ffs_isblock(fs, blksfree, fragstoblks(fs, bno)))
1193 			goto gotit;
1194 		/*
1195 		 * if the requested data block isn't available and we are
1196 		 * trying to allocate a contiguous file, return an error.
1197 		 */
1198 		if ((flags & (B_CONTIG | B_METAONLY)) == B_CONTIG)
1199 			return (0);
1200 	}
1201 
1202 	/*
1203 	 * Take the next available block in this cylinder group.
1204 	 */
1205 	bno = ffs_mapsearch(fs, cgp, bpref, (int)fs->fs_frag);
1206 	if (bno < 0)
1207 		return (0);
1208 	cgp->cg_rotor = ufs_rw32(bno, needswap);
1209 gotit:
1210 	blkno = fragstoblks(fs, bno);
1211 	ffs_clrblock(fs, blksfree, blkno);
1212 	ffs_clusteracct(fs, cgp, blkno, -1);
1213 	ufs_add32(cgp->cg_cs.cs_nbfree, -1, needswap);
1214 	fs->fs_cstotal.cs_nbfree--;
1215 	fs->fs_cs(fs, ufs_rw32(cgp->cg_cgx, needswap)).cs_nbfree--;
1216 	if ((fs->fs_magic == FS_UFS1_MAGIC) &&
1217 	    ((fs->fs_old_flags & FS_FLAGS_UPDATED) == 0)) {
1218 		int cylno;
1219 		cylno = old_cbtocylno(fs, bno);
1220 		KASSERT(cylno >= 0);
1221 		KASSERT(cylno < fs->fs_old_ncyl);
1222 		KASSERT(old_cbtorpos(fs, bno) >= 0);
1223 		KASSERT(fs->fs_old_nrpos == 0 || old_cbtorpos(fs, bno) < fs->fs_old_nrpos);
1224 		ufs_add16(old_cg_blks(fs, cgp, cylno, needswap)[old_cbtorpos(fs, bno)], -1,
1225 		    needswap);
1226 		ufs_add32(old_cg_blktot(cgp, needswap)[cylno], -1, needswap);
1227 	}
1228 	fs->fs_fmod = 1;
1229 	cg = ufs_rw32(cgp->cg_cgx, needswap);
1230 	blkno = cgbase(fs, cg) + bno;
1231 	return (blkno);
1232 }
1233 
1234 /*
1235  * Determine whether an inode can be allocated.
1236  *
1237  * Check to see if an inode is available, and if it is,
1238  * allocate it using the following policy:
1239  *   1) allocate the requested inode.
1240  *   2) allocate the next available inode after the requested
1241  *      inode in the specified cylinder group.
1242  */
1243 static daddr_t
1244 ffs_nodealloccg(struct inode *ip, int cg, daddr_t ipref, int mode, int flags)
1245 {
1246 	struct ufsmount *ump = ip->i_ump;
1247 	struct fs *fs = ip->i_fs;
1248 	struct cg *cgp;
1249 	struct buf *bp, *ibp;
1250 	u_int8_t *inosused;
1251 	int error, start, len, loc, map, i;
1252 	int32_t initediblk;
1253 	daddr_t nalloc;
1254 	struct ufs2_dinode *dp2;
1255 #ifdef FFS_EI
1256 	const int needswap = UFS_FSNEEDSWAP(fs);
1257 #endif
1258 
1259 	KASSERT(mutex_owned(&ump->um_lock));
1260 	UFS_WAPBL_JLOCK_ASSERT(ip->i_ump->um_mountp);
1261 
1262 	if (fs->fs_cs(fs, cg).cs_nifree == 0)
1263 		return (0);
1264 	mutex_exit(&ump->um_lock);
1265 	ibp = NULL;
1266 	initediblk = -1;
1267 retry:
1268 	error = bread(ip->i_devvp, fsbtodb(fs, cgtod(fs, cg)),
1269 		(int)fs->fs_cgsize, NOCRED, B_MODIFY, &bp);
1270 	if (error)
1271 		goto fail;
1272 	cgp = (struct cg *)bp->b_data;
1273 	if (!cg_chkmagic(cgp, needswap) || cgp->cg_cs.cs_nifree == 0)
1274 		goto fail;
1275 
1276 	if (ibp != NULL &&
1277 	    initediblk != ufs_rw32(cgp->cg_initediblk, needswap)) {
1278 		/* Another thread allocated more inodes so we retry the test. */
1279 		brelse(ibp, 0);
1280 		ibp = NULL;
1281 	}
1282 	/*
1283 	 * Check to see if we need to initialize more inodes.
1284 	 */
1285 	if (fs->fs_magic == FS_UFS2_MAGIC && ibp == NULL) {
1286 		initediblk = ufs_rw32(cgp->cg_initediblk, needswap);
1287 		nalloc = fs->fs_ipg - ufs_rw32(cgp->cg_cs.cs_nifree, needswap);
1288 		if (nalloc + INOPB(fs) > initediblk &&
1289 		    initediblk < ufs_rw32(cgp->cg_niblk, needswap)) {
1290 			/*
1291 			 * We have to release the cg buffer here to prevent
1292 			 * a deadlock when reading the inode block will
1293 			 * run a copy-on-write that might use this cg.
1294 			 */
1295 			brelse(bp, 0);
1296 			bp = NULL;
1297 			error = ffs_getblk(ip->i_devvp, fsbtodb(fs,
1298 			    ino_to_fsba(fs, cg * fs->fs_ipg + initediblk)),
1299 			    FFS_NOBLK, fs->fs_bsize, false, &ibp);
1300 			if (error)
1301 				goto fail;
1302 			goto retry;
1303 		}
1304 	}
1305 
1306 	cgp->cg_old_time = ufs_rw32(time_second, needswap);
1307 	if ((fs->fs_magic != FS_UFS1_MAGIC) ||
1308 	    (fs->fs_old_flags & FS_FLAGS_UPDATED))
1309 		cgp->cg_time = ufs_rw64(time_second, needswap);
1310 	inosused = cg_inosused(cgp, needswap);
1311 	if (ipref) {
1312 		ipref %= fs->fs_ipg;
1313 		if (isclr(inosused, ipref))
1314 			goto gotit;
1315 	}
1316 	start = ufs_rw32(cgp->cg_irotor, needswap) / NBBY;
1317 	len = howmany(fs->fs_ipg - ufs_rw32(cgp->cg_irotor, needswap),
1318 		NBBY);
1319 	loc = skpc(0xff, len, &inosused[start]);
1320 	if (loc == 0) {
1321 		len = start + 1;
1322 		start = 0;
1323 		loc = skpc(0xff, len, &inosused[0]);
1324 		if (loc == 0) {
1325 			printf("cg = %d, irotor = %d, fs = %s\n",
1326 			    cg, ufs_rw32(cgp->cg_irotor, needswap),
1327 				fs->fs_fsmnt);
1328 			panic("ffs_nodealloccg: map corrupted");
1329 			/* NOTREACHED */
1330 		}
1331 	}
1332 	i = start + len - loc;
1333 	map = inosused[i] ^ 0xff;
1334 	if (map == 0) {
1335 		printf("fs = %s\n", fs->fs_fsmnt);
1336 		panic("ffs_nodealloccg: block not in map");
1337 	}
1338 	ipref = i * NBBY + ffs(map) - 1;
1339 	cgp->cg_irotor = ufs_rw32(ipref, needswap);
1340 gotit:
1341 	UFS_WAPBL_REGISTER_INODE(ip->i_ump->um_mountp, cg * fs->fs_ipg + ipref,
1342 	    mode);
1343 	/*
1344 	 * Check to see if we need to initialize more inodes.
1345 	 */
1346 	if (ibp != NULL) {
1347 		KASSERT(initediblk == ufs_rw32(cgp->cg_initediblk, needswap));
1348 		memset(ibp->b_data, 0, fs->fs_bsize);
1349 		dp2 = (struct ufs2_dinode *)(ibp->b_data);
1350 		for (i = 0; i < INOPB(fs); i++) {
1351 			/*
1352 			 * Don't bother to swap, it's supposed to be
1353 			 * random, after all.
1354 			 */
1355 			dp2->di_gen = (arc4random() & INT32_MAX) / 2 + 1;
1356 			dp2++;
1357 		}
1358 		initediblk += INOPB(fs);
1359 		cgp->cg_initediblk = ufs_rw32(initediblk, needswap);
1360 	}
1361 
1362 	mutex_enter(&ump->um_lock);
1363 	ACTIVECG_CLR(fs, cg);
1364 	setbit(inosused, ipref);
1365 	ufs_add32(cgp->cg_cs.cs_nifree, -1, needswap);
1366 	fs->fs_cstotal.cs_nifree--;
1367 	fs->fs_cs(fs, cg).cs_nifree--;
1368 	fs->fs_fmod = 1;
1369 	if ((mode & IFMT) == IFDIR) {
1370 		ufs_add32(cgp->cg_cs.cs_ndir, 1, needswap);
1371 		fs->fs_cstotal.cs_ndir++;
1372 		fs->fs_cs(fs, cg).cs_ndir++;
1373 	}
1374 	mutex_exit(&ump->um_lock);
1375 	if (ibp != NULL) {
1376 		bwrite(bp);
1377 		bawrite(ibp);
1378 	} else
1379 		bdwrite(bp);
1380 	return (cg * fs->fs_ipg + ipref);
1381  fail:
1382 	if (bp != NULL)
1383 		brelse(bp, 0);
1384 	if (ibp != NULL)
1385 		brelse(ibp, 0);
1386 	mutex_enter(&ump->um_lock);
1387 	return (0);
1388 }
1389 
1390 /*
1391  * Allocate a block or fragment.
1392  *
1393  * The specified block or fragment is removed from the
1394  * free map, possibly fragmenting a block in the process.
1395  *
1396  * This implementation should mirror fs_blkfree
1397  *
1398  * => um_lock not held on entry or exit
1399  */
1400 int
1401 ffs_blkalloc(struct inode *ip, daddr_t bno, long size)
1402 {
1403 	int error;
1404 
1405 	error = ffs_check_bad_allocation(__func__, ip->i_fs, bno, size,
1406 	    ip->i_dev, ip->i_uid);
1407 	if (error)
1408 		return error;
1409 
1410 	return ffs_blkalloc_ump(ip->i_ump, bno, size);
1411 }
1412 
1413 int
1414 ffs_blkalloc_ump(struct ufsmount *ump, daddr_t bno, long size)
1415 {
1416 	struct fs *fs = ump->um_fs;
1417 	struct cg *cgp;
1418 	struct buf *bp;
1419 	int32_t fragno, cgbno;
1420 	int i, error, cg, blk, frags, bbase;
1421 	u_int8_t *blksfree;
1422 	const int needswap = UFS_FSNEEDSWAP(fs);
1423 
1424 	KASSERT((u_int)size <= fs->fs_bsize && fragoff(fs, size) == 0 &&
1425 	    fragnum(fs, bno) + numfrags(fs, size) <= fs->fs_frag);
1426 	KASSERT(bno < fs->fs_size);
1427 
1428 	cg = dtog(fs, bno);
1429 	error = bread(ump->um_devvp, fsbtodb(fs, cgtod(fs, cg)),
1430 		(int)fs->fs_cgsize, NOCRED, B_MODIFY, &bp);
1431 	if (error) {
1432 		brelse(bp, 0);
1433 		return error;
1434 	}
1435 	cgp = (struct cg *)bp->b_data;
1436 	if (!cg_chkmagic(cgp, needswap)) {
1437 		brelse(bp, 0);
1438 		return EIO;
1439 	}
1440 	cgp->cg_old_time = ufs_rw32(time_second, needswap);
1441 	cgp->cg_time = ufs_rw64(time_second, needswap);
1442 	cgbno = dtogd(fs, bno);
1443 	blksfree = cg_blksfree(cgp, needswap);
1444 
1445 	mutex_enter(&ump->um_lock);
1446 	if (size == fs->fs_bsize) {
1447 		fragno = fragstoblks(fs, cgbno);
1448 		if (!ffs_isblock(fs, blksfree, fragno)) {
1449 			mutex_exit(&ump->um_lock);
1450 			brelse(bp, 0);
1451 			return EBUSY;
1452 		}
1453 		ffs_clrblock(fs, blksfree, fragno);
1454 		ffs_clusteracct(fs, cgp, fragno, -1);
1455 		ufs_add32(cgp->cg_cs.cs_nbfree, -1, needswap);
1456 		fs->fs_cstotal.cs_nbfree--;
1457 		fs->fs_cs(fs, cg).cs_nbfree--;
1458 	} else {
1459 		bbase = cgbno - fragnum(fs, cgbno);
1460 
1461 		frags = numfrags(fs, size);
1462 		for (i = 0; i < frags; i++) {
1463 			if (isclr(blksfree, cgbno + i)) {
1464 				mutex_exit(&ump->um_lock);
1465 				brelse(bp, 0);
1466 				return EBUSY;
1467 			}
1468 		}
1469 		/*
1470 		 * if a complete block is being split, account for it
1471 		 */
1472 		fragno = fragstoblks(fs, bbase);
1473 		if (ffs_isblock(fs, blksfree, fragno)) {
1474 			ufs_add32(cgp->cg_cs.cs_nffree, fs->fs_frag, needswap);
1475 			fs->fs_cstotal.cs_nffree += fs->fs_frag;
1476 			fs->fs_cs(fs, cg).cs_nffree += fs->fs_frag;
1477 			ffs_clusteracct(fs, cgp, fragno, -1);
1478 			ufs_add32(cgp->cg_cs.cs_nbfree, -1, needswap);
1479 			fs->fs_cstotal.cs_nbfree--;
1480 			fs->fs_cs(fs, cg).cs_nbfree--;
1481 		}
1482 		/*
1483 		 * decrement the counts associated with the old frags
1484 		 */
1485 		blk = blkmap(fs, blksfree, bbase);
1486 		ffs_fragacct(fs, blk, cgp->cg_frsum, -1, needswap);
1487 		/*
1488 		 * allocate the fragment
1489 		 */
1490 		for (i = 0; i < frags; i++) {
1491 			clrbit(blksfree, cgbno + i);
1492 		}
1493 		ufs_add32(cgp->cg_cs.cs_nffree, -i, needswap);
1494 		fs->fs_cstotal.cs_nffree -= i;
1495 		fs->fs_cs(fs, cg).cs_nffree -= i;
1496 		/*
1497 		 * add back in counts associated with the new frags
1498 		 */
1499 		blk = blkmap(fs, blksfree, bbase);
1500 		ffs_fragacct(fs, blk, cgp->cg_frsum, 1, needswap);
1501 	}
1502 	fs->fs_fmod = 1;
1503 	ACTIVECG_CLR(fs, cg);
1504 	mutex_exit(&ump->um_lock);
1505 	bdwrite(bp);
1506 	return 0;
1507 }
1508 
1509 /*
1510  * Free a block or fragment.
1511  *
1512  * The specified block or fragment is placed back in the
1513  * free map. If a fragment is deallocated, a possible
1514  * block reassembly is checked.
1515  *
1516  * => um_lock not held on entry or exit
1517  */
1518 void
1519 ffs_blkfree(struct fs *fs, struct vnode *devvp, daddr_t bno, long size,
1520     ino_t inum)
1521 {
1522 	struct cg *cgp;
1523 	struct buf *bp;
1524 	struct ufsmount *ump;
1525 	daddr_t cgblkno;
1526 	int error, cg;
1527 	dev_t dev;
1528 	const bool devvp_is_snapshot = (devvp->v_type != VBLK);
1529 #ifdef FFS_EI
1530 	const int needswap = UFS_FSNEEDSWAP(fs);
1531 #endif
1532 
1533 	KASSERT(!devvp_is_snapshot);
1534 
1535 	cg = dtog(fs, bno);
1536 	dev = devvp->v_rdev;
1537 	ump = VFSTOUFS(devvp->v_specmountpoint);
1538 	KASSERT(fs == ump->um_fs);
1539 	cgblkno = fsbtodb(fs, cgtod(fs, cg));
1540 	if (ffs_snapblkfree(fs, devvp, bno, size, inum))
1541 		return;
1542 
1543 	error = ffs_check_bad_allocation(__func__, fs, bno, size, dev, inum);
1544 	if (error)
1545 		return;
1546 
1547 	error = bread(devvp, cgblkno, (int)fs->fs_cgsize,
1548 	    NOCRED, B_MODIFY, &bp);
1549 	if (error) {
1550 		brelse(bp, 0);
1551 		return;
1552 	}
1553 	cgp = (struct cg *)bp->b_data;
1554 	if (!cg_chkmagic(cgp, needswap)) {
1555 		brelse(bp, 0);
1556 		return;
1557 	}
1558 
1559 	ffs_blkfree_common(ump, fs, dev, bp, bno, size, devvp_is_snapshot);
1560 
1561 	bdwrite(bp);
1562 }
1563 
1564 /*
1565  * Free a block or fragment from a snapshot cg copy.
1566  *
1567  * The specified block or fragment is placed back in the
1568  * free map. If a fragment is deallocated, a possible
1569  * block reassembly is checked.
1570  *
1571  * => um_lock not held on entry or exit
1572  */
1573 void
1574 ffs_blkfree_snap(struct fs *fs, struct vnode *devvp, daddr_t bno, long size,
1575     ino_t inum)
1576 {
1577 	struct cg *cgp;
1578 	struct buf *bp;
1579 	struct ufsmount *ump;
1580 	daddr_t cgblkno;
1581 	int error, cg;
1582 	dev_t dev;
1583 	const bool devvp_is_snapshot = (devvp->v_type != VBLK);
1584 #ifdef FFS_EI
1585 	const int needswap = UFS_FSNEEDSWAP(fs);
1586 #endif
1587 
1588 	KASSERT(devvp_is_snapshot);
1589 
1590 	cg = dtog(fs, bno);
1591 	dev = VTOI(devvp)->i_devvp->v_rdev;
1592 	ump = VFSTOUFS(devvp->v_mount);
1593 	cgblkno = fragstoblks(fs, cgtod(fs, cg));
1594 
1595 	error = ffs_check_bad_allocation(__func__, fs, bno, size, dev, inum);
1596 	if (error)
1597 		return;
1598 
1599 	error = bread(devvp, cgblkno, (int)fs->fs_cgsize,
1600 	    NOCRED, B_MODIFY, &bp);
1601 	if (error) {
1602 		brelse(bp, 0);
1603 		return;
1604 	}
1605 	cgp = (struct cg *)bp->b_data;
1606 	if (!cg_chkmagic(cgp, needswap)) {
1607 		brelse(bp, 0);
1608 		return;
1609 	}
1610 
1611 	ffs_blkfree_common(ump, fs, dev, bp, bno, size, devvp_is_snapshot);
1612 
1613 	bdwrite(bp);
1614 }
1615 
1616 static void
1617 ffs_blkfree_common(struct ufsmount *ump, struct fs *fs, dev_t dev,
1618     struct buf *bp, daddr_t bno, long size, bool devvp_is_snapshot)
1619 {
1620 	struct cg *cgp;
1621 	int32_t fragno, cgbno;
1622 	int i, cg, blk, frags, bbase;
1623 	u_int8_t *blksfree;
1624 	const int needswap = UFS_FSNEEDSWAP(fs);
1625 
1626 	cg = dtog(fs, bno);
1627 	cgp = (struct cg *)bp->b_data;
1628 	cgp->cg_old_time = ufs_rw32(time_second, needswap);
1629 	if ((fs->fs_magic != FS_UFS1_MAGIC) ||
1630 	    (fs->fs_old_flags & FS_FLAGS_UPDATED))
1631 		cgp->cg_time = ufs_rw64(time_second, needswap);
1632 	cgbno = dtogd(fs, bno);
1633 	blksfree = cg_blksfree(cgp, needswap);
1634 	mutex_enter(&ump->um_lock);
1635 	if (size == fs->fs_bsize) {
1636 		fragno = fragstoblks(fs, cgbno);
1637 		if (!ffs_isfreeblock(fs, blksfree, fragno)) {
1638 			if (devvp_is_snapshot) {
1639 				mutex_exit(&ump->um_lock);
1640 				return;
1641 			}
1642 			printf("dev = 0x%llx, block = %" PRId64 ", fs = %s\n",
1643 			    (unsigned long long)dev, bno, fs->fs_fsmnt);
1644 			panic("blkfree: freeing free block");
1645 		}
1646 		ffs_setblock(fs, blksfree, fragno);
1647 		ffs_clusteracct(fs, cgp, fragno, 1);
1648 		ufs_add32(cgp->cg_cs.cs_nbfree, 1, needswap);
1649 		fs->fs_cstotal.cs_nbfree++;
1650 		fs->fs_cs(fs, cg).cs_nbfree++;
1651 		if ((fs->fs_magic == FS_UFS1_MAGIC) &&
1652 		    ((fs->fs_old_flags & FS_FLAGS_UPDATED) == 0)) {
1653 			i = old_cbtocylno(fs, cgbno);
1654 			KASSERT(i >= 0);
1655 			KASSERT(i < fs->fs_old_ncyl);
1656 			KASSERT(old_cbtorpos(fs, cgbno) >= 0);
1657 			KASSERT(fs->fs_old_nrpos == 0 || old_cbtorpos(fs, cgbno) < fs->fs_old_nrpos);
1658 			ufs_add16(old_cg_blks(fs, cgp, i, needswap)[old_cbtorpos(fs, cgbno)], 1,
1659 			    needswap);
1660 			ufs_add32(old_cg_blktot(cgp, needswap)[i], 1, needswap);
1661 		}
1662 	} else {
1663 		bbase = cgbno - fragnum(fs, cgbno);
1664 		/*
1665 		 * decrement the counts associated with the old frags
1666 		 */
1667 		blk = blkmap(fs, blksfree, bbase);
1668 		ffs_fragacct(fs, blk, cgp->cg_frsum, -1, needswap);
1669 		/*
1670 		 * deallocate the fragment
1671 		 */
1672 		frags = numfrags(fs, size);
1673 		for (i = 0; i < frags; i++) {
1674 			if (isset(blksfree, cgbno + i)) {
1675 				printf("dev = 0x%llx, block = %" PRId64
1676 				       ", fs = %s\n",
1677 				    (unsigned long long)dev, bno + i,
1678 				    fs->fs_fsmnt);
1679 				panic("blkfree: freeing free frag");
1680 			}
1681 			setbit(blksfree, cgbno + i);
1682 		}
1683 		ufs_add32(cgp->cg_cs.cs_nffree, i, needswap);
1684 		fs->fs_cstotal.cs_nffree += i;
1685 		fs->fs_cs(fs, cg).cs_nffree += i;
1686 		/*
1687 		 * add back in counts associated with the new frags
1688 		 */
1689 		blk = blkmap(fs, blksfree, bbase);
1690 		ffs_fragacct(fs, blk, cgp->cg_frsum, 1, needswap);
1691 		/*
1692 		 * if a complete block has been reassembled, account for it
1693 		 */
1694 		fragno = fragstoblks(fs, bbase);
1695 		if (ffs_isblock(fs, blksfree, fragno)) {
1696 			ufs_add32(cgp->cg_cs.cs_nffree, -fs->fs_frag, needswap);
1697 			fs->fs_cstotal.cs_nffree -= fs->fs_frag;
1698 			fs->fs_cs(fs, cg).cs_nffree -= fs->fs_frag;
1699 			ffs_clusteracct(fs, cgp, fragno, 1);
1700 			ufs_add32(cgp->cg_cs.cs_nbfree, 1, needswap);
1701 			fs->fs_cstotal.cs_nbfree++;
1702 			fs->fs_cs(fs, cg).cs_nbfree++;
1703 			if ((fs->fs_magic == FS_UFS1_MAGIC) &&
1704 			    ((fs->fs_old_flags & FS_FLAGS_UPDATED) == 0)) {
1705 				i = old_cbtocylno(fs, bbase);
1706 				KASSERT(i >= 0);
1707 				KASSERT(i < fs->fs_old_ncyl);
1708 				KASSERT(old_cbtorpos(fs, bbase) >= 0);
1709 				KASSERT(fs->fs_old_nrpos == 0 || old_cbtorpos(fs, bbase) < fs->fs_old_nrpos);
1710 				ufs_add16(old_cg_blks(fs, cgp, i, needswap)[old_cbtorpos(fs,
1711 				    bbase)], 1, needswap);
1712 				ufs_add32(old_cg_blktot(cgp, needswap)[i], 1, needswap);
1713 			}
1714 		}
1715 	}
1716 	fs->fs_fmod = 1;
1717 	ACTIVECG_CLR(fs, cg);
1718 	mutex_exit(&ump->um_lock);
1719 }
1720 
1721 /*
1722  * Free an inode.
1723  */
1724 int
1725 ffs_vfree(struct vnode *vp, ino_t ino, int mode)
1726 {
1727 
1728 	return ffs_freefile(vp->v_mount, ino, mode);
1729 }
1730 
1731 /*
1732  * Do the actual free operation.
1733  * The specified inode is placed back in the free map.
1734  *
1735  * => um_lock not held on entry or exit
1736  */
1737 int
1738 ffs_freefile(struct mount *mp, ino_t ino, int mode)
1739 {
1740 	struct ufsmount *ump = VFSTOUFS(mp);
1741 	struct fs *fs = ump->um_fs;
1742 	struct vnode *devvp;
1743 	struct cg *cgp;
1744 	struct buf *bp;
1745 	int error, cg;
1746 	daddr_t cgbno;
1747 	dev_t dev;
1748 #ifdef FFS_EI
1749 	const int needswap = UFS_FSNEEDSWAP(fs);
1750 #endif
1751 
1752 	cg = ino_to_cg(fs, ino);
1753 	devvp = ump->um_devvp;
1754 	dev = devvp->v_rdev;
1755 	cgbno = fsbtodb(fs, cgtod(fs, cg));
1756 
1757 	if ((u_int)ino >= fs->fs_ipg * fs->fs_ncg)
1758 		panic("ifree: range: dev = 0x%llx, ino = %llu, fs = %s",
1759 		    (long long)dev, (unsigned long long)ino, fs->fs_fsmnt);
1760 	error = bread(devvp, cgbno, (int)fs->fs_cgsize,
1761 	    NOCRED, B_MODIFY, &bp);
1762 	if (error) {
1763 		brelse(bp, 0);
1764 		return (error);
1765 	}
1766 	cgp = (struct cg *)bp->b_data;
1767 	if (!cg_chkmagic(cgp, needswap)) {
1768 		brelse(bp, 0);
1769 		return (0);
1770 	}
1771 
1772 	ffs_freefile_common(ump, fs, dev, bp, ino, mode, false);
1773 
1774 	bdwrite(bp);
1775 
1776 	return 0;
1777 }
1778 
1779 int
1780 ffs_freefile_snap(struct fs *fs, struct vnode *devvp, ino_t ino, int mode)
1781 {
1782 	struct ufsmount *ump;
1783 	struct cg *cgp;
1784 	struct buf *bp;
1785 	int error, cg;
1786 	daddr_t cgbno;
1787 	dev_t dev;
1788 #ifdef FFS_EI
1789 	const int needswap = UFS_FSNEEDSWAP(fs);
1790 #endif
1791 
1792 	KASSERT(devvp->v_type != VBLK);
1793 
1794 	cg = ino_to_cg(fs, ino);
1795 	dev = VTOI(devvp)->i_devvp->v_rdev;
1796 	ump = VFSTOUFS(devvp->v_mount);
1797 	cgbno = fragstoblks(fs, cgtod(fs, cg));
1798 	if ((u_int)ino >= fs->fs_ipg * fs->fs_ncg)
1799 		panic("ifree: range: dev = 0x%llx, ino = %llu, fs = %s",
1800 		    (unsigned long long)dev, (unsigned long long)ino,
1801 		    fs->fs_fsmnt);
1802 	error = bread(devvp, cgbno, (int)fs->fs_cgsize,
1803 	    NOCRED, B_MODIFY, &bp);
1804 	if (error) {
1805 		brelse(bp, 0);
1806 		return (error);
1807 	}
1808 	cgp = (struct cg *)bp->b_data;
1809 	if (!cg_chkmagic(cgp, needswap)) {
1810 		brelse(bp, 0);
1811 		return (0);
1812 	}
1813 	ffs_freefile_common(ump, fs, dev, bp, ino, mode, true);
1814 
1815 	bdwrite(bp);
1816 
1817 	return 0;
1818 }
1819 
1820 static void
1821 ffs_freefile_common(struct ufsmount *ump, struct fs *fs, dev_t dev,
1822     struct buf *bp, ino_t ino, int mode, bool devvp_is_snapshot)
1823 {
1824 	int cg;
1825 	struct cg *cgp;
1826 	u_int8_t *inosused;
1827 #ifdef FFS_EI
1828 	const int needswap = UFS_FSNEEDSWAP(fs);
1829 #endif
1830 
1831 	cg = ino_to_cg(fs, ino);
1832 	cgp = (struct cg *)bp->b_data;
1833 	cgp->cg_old_time = ufs_rw32(time_second, needswap);
1834 	if ((fs->fs_magic != FS_UFS1_MAGIC) ||
1835 	    (fs->fs_old_flags & FS_FLAGS_UPDATED))
1836 		cgp->cg_time = ufs_rw64(time_second, needswap);
1837 	inosused = cg_inosused(cgp, needswap);
1838 	ino %= fs->fs_ipg;
1839 	if (isclr(inosused, ino)) {
1840 		printf("ifree: dev = 0x%llx, ino = %llu, fs = %s\n",
1841 		    (unsigned long long)dev, (unsigned long long)ino +
1842 		    cg * fs->fs_ipg, fs->fs_fsmnt);
1843 		if (fs->fs_ronly == 0)
1844 			panic("ifree: freeing free inode");
1845 	}
1846 	clrbit(inosused, ino);
1847 	if (!devvp_is_snapshot)
1848 		UFS_WAPBL_UNREGISTER_INODE(ump->um_mountp,
1849 		    ino + cg * fs->fs_ipg, mode);
1850 	if (ino < ufs_rw32(cgp->cg_irotor, needswap))
1851 		cgp->cg_irotor = ufs_rw32(ino, needswap);
1852 	ufs_add32(cgp->cg_cs.cs_nifree, 1, needswap);
1853 	mutex_enter(&ump->um_lock);
1854 	fs->fs_cstotal.cs_nifree++;
1855 	fs->fs_cs(fs, cg).cs_nifree++;
1856 	if ((mode & IFMT) == IFDIR) {
1857 		ufs_add32(cgp->cg_cs.cs_ndir, -1, needswap);
1858 		fs->fs_cstotal.cs_ndir--;
1859 		fs->fs_cs(fs, cg).cs_ndir--;
1860 	}
1861 	fs->fs_fmod = 1;
1862 	ACTIVECG_CLR(fs, cg);
1863 	mutex_exit(&ump->um_lock);
1864 }
1865 
1866 /*
1867  * Check to see if a file is free.
1868  */
1869 int
1870 ffs_checkfreefile(struct fs *fs, struct vnode *devvp, ino_t ino)
1871 {
1872 	struct cg *cgp;
1873 	struct buf *bp;
1874 	daddr_t cgbno;
1875 	int ret, cg;
1876 	u_int8_t *inosused;
1877 	const bool devvp_is_snapshot = (devvp->v_type != VBLK);
1878 
1879 	KASSERT(devvp_is_snapshot);
1880 
1881 	cg = ino_to_cg(fs, ino);
1882 	if (devvp_is_snapshot)
1883 		cgbno = fragstoblks(fs, cgtod(fs, cg));
1884 	else
1885 		cgbno = fsbtodb(fs, cgtod(fs, cg));
1886 	if ((u_int)ino >= fs->fs_ipg * fs->fs_ncg)
1887 		return 1;
1888 	if (bread(devvp, cgbno, (int)fs->fs_cgsize, NOCRED, 0, &bp)) {
1889 		brelse(bp, 0);
1890 		return 1;
1891 	}
1892 	cgp = (struct cg *)bp->b_data;
1893 	if (!cg_chkmagic(cgp, UFS_FSNEEDSWAP(fs))) {
1894 		brelse(bp, 0);
1895 		return 1;
1896 	}
1897 	inosused = cg_inosused(cgp, UFS_FSNEEDSWAP(fs));
1898 	ino %= fs->fs_ipg;
1899 	ret = isclr(inosused, ino);
1900 	brelse(bp, 0);
1901 	return ret;
1902 }
1903 
1904 /*
1905  * Find a block of the specified size in the specified cylinder group.
1906  *
1907  * It is a panic if a request is made to find a block if none are
1908  * available.
1909  */
1910 static int32_t
1911 ffs_mapsearch(struct fs *fs, struct cg *cgp, daddr_t bpref, int allocsiz)
1912 {
1913 	int32_t bno;
1914 	int start, len, loc, i;
1915 	int blk, field, subfield, pos;
1916 	int ostart, olen;
1917 	u_int8_t *blksfree;
1918 #ifdef FFS_EI
1919 	const int needswap = UFS_FSNEEDSWAP(fs);
1920 #endif
1921 
1922 	/* KASSERT(mutex_owned(&ump->um_lock)); */
1923 
1924 	/*
1925 	 * find the fragment by searching through the free block
1926 	 * map for an appropriate bit pattern
1927 	 */
1928 	if (bpref)
1929 		start = dtogd(fs, bpref) / NBBY;
1930 	else
1931 		start = ufs_rw32(cgp->cg_frotor, needswap) / NBBY;
1932 	blksfree = cg_blksfree(cgp, needswap);
1933 	len = howmany(fs->fs_fpg, NBBY) - start;
1934 	ostart = start;
1935 	olen = len;
1936 	loc = scanc((u_int)len,
1937 		(const u_char *)&blksfree[start],
1938 		(const u_char *)fragtbl[fs->fs_frag],
1939 		(1 << (allocsiz - 1 + (fs->fs_frag & (NBBY - 1)))));
1940 	if (loc == 0) {
1941 		len = start + 1;
1942 		start = 0;
1943 		loc = scanc((u_int)len,
1944 			(const u_char *)&blksfree[0],
1945 			(const u_char *)fragtbl[fs->fs_frag],
1946 			(1 << (allocsiz - 1 + (fs->fs_frag & (NBBY - 1)))));
1947 		if (loc == 0) {
1948 			printf("start = %d, len = %d, fs = %s\n",
1949 			    ostart, olen, fs->fs_fsmnt);
1950 			printf("offset=%d %ld\n",
1951 				ufs_rw32(cgp->cg_freeoff, needswap),
1952 				(long)blksfree - (long)cgp);
1953 			printf("cg %d\n", cgp->cg_cgx);
1954 			panic("ffs_alloccg: map corrupted");
1955 			/* NOTREACHED */
1956 		}
1957 	}
1958 	bno = (start + len - loc) * NBBY;
1959 	cgp->cg_frotor = ufs_rw32(bno, needswap);
1960 	/*
1961 	 * found the byte in the map
1962 	 * sift through the bits to find the selected frag
1963 	 */
1964 	for (i = bno + NBBY; bno < i; bno += fs->fs_frag) {
1965 		blk = blkmap(fs, blksfree, bno);
1966 		blk <<= 1;
1967 		field = around[allocsiz];
1968 		subfield = inside[allocsiz];
1969 		for (pos = 0; pos <= fs->fs_frag - allocsiz; pos++) {
1970 			if ((blk & field) == subfield)
1971 				return (bno + pos);
1972 			field <<= 1;
1973 			subfield <<= 1;
1974 		}
1975 	}
1976 	printf("bno = %d, fs = %s\n", bno, fs->fs_fsmnt);
1977 	panic("ffs_alloccg: block not in map");
1978 	/* return (-1); */
1979 }
1980 
1981 /*
1982  * Fserr prints the name of a file system with an error diagnostic.
1983  *
1984  * The form of the error message is:
1985  *	fs: error message
1986  */
1987 static void
1988 ffs_fserr(struct fs *fs, u_int uid, const char *cp)
1989 {
1990 
1991 	log(LOG_ERR, "uid %d, pid %d, command %s, on %s: %s\n",
1992 	    uid, curproc->p_pid, curproc->p_comm, fs->fs_fsmnt, cp);
1993 }
1994