xref: /freebsd/sys/ufs/ffs/ffs_inode.c (revision 830940567b49bb0c08dfaed40418999e76616909)
1 /*-
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)ffs_inode.c	8.13 (Berkeley) 4/21/95
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_quota.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/mount.h>
40 #include <sys/proc.h>
41 #include <sys/bio.h>
42 #include <sys/buf.h>
43 #include <sys/vnode.h>
44 #include <sys/malloc.h>
45 #include <sys/resourcevar.h>
46 #include <sys/vmmeter.h>
47 #include <sys/stat.h>
48 
49 #include <vm/vm.h>
50 #include <vm/vm_extern.h>
51 #include <vm/vm_object.h>
52 
53 #include <ufs/ufs/extattr.h>
54 #include <ufs/ufs/quota.h>
55 #include <ufs/ufs/ufsmount.h>
56 #include <ufs/ufs/inode.h>
57 #include <ufs/ufs/ufs_extern.h>
58 
59 #include <ufs/ffs/fs.h>
60 #include <ufs/ffs/ffs_extern.h>
61 
62 static int ffs_indirtrunc(struct inode *, ufs2_daddr_t, ufs2_daddr_t,
63 	    ufs2_daddr_t, int, ufs2_daddr_t *);
64 
65 /*
66  * Update the access, modified, and inode change times as specified by the
67  * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
68  * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
69  * the timestamp update).  The IN_LAZYMOD flag is set to force a write
70  * later if not now.  The IN_LAZYACCESS is set instead of IN_MODIFIED if the fs
71  * is currently being suspended (or is suspended) and vnode has been accessed.
72  * If we write now, then clear IN_MODIFIED, IN_LAZYACCESS and IN_LAZYMOD to
73  * reflect the presumably successful write, and if waitfor is set, then wait
74  * for the write to complete.
75  */
76 int
77 ffs_update(vp, waitfor)
78 	struct vnode *vp;
79 	int waitfor;
80 {
81 	struct fs *fs;
82 	struct buf *bp;
83 	struct inode *ip;
84 	int error;
85 
86 	ASSERT_VOP_ELOCKED(vp, "ffs_update");
87 	ufs_itimes(vp);
88 	ip = VTOI(vp);
89 	if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
90 		return (0);
91 	ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED);
92 	fs = ip->i_fs;
93 	if (fs->fs_ronly)
94 		return (0);
95 	/*
96 	 * Ensure that uid and gid are correct. This is a temporary
97 	 * fix until fsck has been changed to do the update.
98 	 */
99 	if (fs->fs_magic == FS_UFS1_MAGIC &&		/* XXX */
100 	    fs->fs_old_inodefmt < FS_44INODEFMT) {	/* XXX */
101 		ip->i_din1->di_ouid = ip->i_uid;	/* XXX */
102 		ip->i_din1->di_ogid = ip->i_gid;	/* XXX */
103 	}						/* XXX */
104 	error = bread(ip->i_devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
105 		(int)fs->fs_bsize, NOCRED, &bp);
106 	if (error) {
107 		brelse(bp);
108 		return (error);
109 	}
110 	if (DOINGSOFTDEP(vp))
111 		softdep_update_inodeblock(ip, bp, waitfor);
112 	else if (ip->i_effnlink != ip->i_nlink)
113 		panic("ffs_update: bad link cnt");
114 	if (ip->i_ump->um_fstype == UFS1)
115 		*((struct ufs1_dinode *)bp->b_data +
116 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din1;
117 	else
118 		*((struct ufs2_dinode *)bp->b_data +
119 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din2;
120 	if (waitfor && !DOINGASYNC(vp)) {
121 		return (bwrite(bp));
122 	} else if (vm_page_count_severe() || buf_dirty_count_severe()) {
123 		return (bwrite(bp));
124 	} else {
125 		if (bp->b_bufsize == fs->fs_bsize)
126 			bp->b_flags |= B_CLUSTEROK;
127 		bdwrite(bp);
128 		return (0);
129 	}
130 }
131 
132 static void
133 ffs_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
134 {
135 	vm_object_t object;
136 
137 	if ((object = vp->v_object) == NULL)
138 		return;
139 	VM_OBJECT_LOCK(object);
140 	vm_object_page_remove(object, start, end, FALSE);
141 	VM_OBJECT_UNLOCK(object);
142 }
143 
144 #define	SINGLE	0	/* index of single indirect block */
145 #define	DOUBLE	1	/* index of double indirect block */
146 #define	TRIPLE	2	/* index of triple indirect block */
147 /*
148  * Truncate the inode ip to at most length size, freeing the
149  * disk blocks.
150  */
151 int
152 ffs_truncate(vp, length, flags, cred, td)
153 	struct vnode *vp;
154 	off_t length;
155 	int flags;
156 	struct ucred *cred;
157 	struct thread *td;
158 {
159 	struct inode *ip;
160 	ufs2_daddr_t bn, lbn, lastblock, lastiblock[NIADDR], indir_lbn[NIADDR];
161 	ufs2_daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
162 	ufs2_daddr_t count, blocksreleased = 0, datablocks;
163 	struct bufobj *bo;
164 	struct fs *fs;
165 	struct buf *bp;
166 	struct ufsmount *ump;
167 	int needextclean, softdepslowdown, extblocks;
168 	int offset, size, level, nblocks;
169 	int i, error, allerror;
170 	off_t osize;
171 
172 	ip = VTOI(vp);
173 	fs = ip->i_fs;
174 	ump = ip->i_ump;
175 	bo = &vp->v_bufobj;
176 
177 	ASSERT_VOP_LOCKED(vp, "ffs_truncate");
178 
179 	if (length < 0)
180 		return (EINVAL);
181 	/*
182 	 * Historically clients did not have to specify which data
183 	 * they were truncating. So, if not specified, we assume
184 	 * traditional behavior, e.g., just the normal data.
185 	 */
186 	if ((flags & (IO_EXT | IO_NORMAL)) == 0)
187 		flags |= IO_NORMAL;
188 	/*
189 	 * If we are truncating the extended-attributes, and cannot
190 	 * do it with soft updates, then do it slowly here. If we are
191 	 * truncating both the extended attributes and the file contents
192 	 * (e.g., the file is being unlinked), then pick it off with
193 	 * soft updates below.
194 	 */
195 	needextclean = 0;
196 	softdepslowdown = DOINGSOFTDEP(vp) && softdep_slowdown(vp);
197 	extblocks = 0;
198 	datablocks = DIP(ip, i_blocks);
199 	if (fs->fs_magic == FS_UFS2_MAGIC && ip->i_din2->di_extsize > 0) {
200 		extblocks = btodb(fragroundup(fs, ip->i_din2->di_extsize));
201 		datablocks -= extblocks;
202 	}
203 	if ((flags & IO_EXT) && extblocks > 0) {
204 		if (DOINGSOFTDEP(vp) && softdepslowdown == 0 && length == 0) {
205 			if ((flags & IO_NORMAL) == 0) {
206 				softdep_setup_freeblocks(ip, length, IO_EXT);
207 				return (0);
208 			}
209 			needextclean = 1;
210 		} else {
211 			if (length != 0)
212 				panic("ffs_truncate: partial trunc of extdata");
213 			if ((error = ffs_syncvnode(vp, MNT_WAIT)) != 0)
214 				return (error);
215 			osize = ip->i_din2->di_extsize;
216 			ip->i_din2->di_blocks -= extblocks;
217 #ifdef QUOTA
218 			(void) chkdq(ip, -extblocks, NOCRED, 0);
219 #endif
220 			vinvalbuf(vp, V_ALT, 0, 0);
221 			ffs_pages_remove(vp,
222 			    OFF_TO_IDX(lblktosize(fs, -extblocks)), 0);
223 			ip->i_din2->di_extsize = 0;
224 			for (i = 0; i < NXADDR; i++) {
225 				oldblks[i] = ip->i_din2->di_extb[i];
226 				ip->i_din2->di_extb[i] = 0;
227 			}
228 			ip->i_flag |= IN_CHANGE;
229 			if ((error = ffs_update(vp, 1)))
230 				return (error);
231 			for (i = 0; i < NXADDR; i++) {
232 				if (oldblks[i] == 0)
233 					continue;
234 				ffs_blkfree(ump, fs, ip->i_devvp, oldblks[i],
235 				    sblksize(fs, osize, i), ip->i_number);
236 			}
237 		}
238 	}
239 	if ((flags & IO_NORMAL) == 0)
240 		return (0);
241 	if (length > fs->fs_maxfilesize)
242 		return (EFBIG);
243 	if (vp->v_type == VLNK &&
244 	    (ip->i_size < vp->v_mount->mnt_maxsymlinklen ||
245 	     datablocks == 0)) {
246 #ifdef INVARIANTS
247 		if (length != 0)
248 			panic("ffs_truncate: partial truncate of symlink");
249 #endif
250 		bzero(SHORTLINK(ip), (u_int)ip->i_size);
251 		ip->i_size = 0;
252 		DIP_SET(ip, i_size, 0);
253 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
254 		if (needextclean)
255 			softdep_setup_freeblocks(ip, length, IO_EXT);
256 		return (ffs_update(vp, 1));
257 	}
258 	if (ip->i_size == length) {
259 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
260 		if (needextclean)
261 			softdep_setup_freeblocks(ip, length, IO_EXT);
262 		return (ffs_update(vp, 0));
263 	}
264 	if (fs->fs_ronly)
265 		panic("ffs_truncate: read-only filesystem");
266 #ifdef QUOTA
267 	error = getinoquota(ip);
268 	if (error)
269 		return (error);
270 #endif
271 	if ((ip->i_flags & SF_SNAPSHOT) != 0)
272 		ffs_snapremove(vp);
273 	vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
274 	if (DOINGSOFTDEP(vp)) {
275 		if (length > 0 || softdepslowdown) {
276 			/*
277 			 * If a file is only partially truncated, then
278 			 * we have to clean up the data structures
279 			 * describing the allocation past the truncation
280 			 * point. Finding and deallocating those structures
281 			 * is a lot of work. Since partial truncation occurs
282 			 * rarely, we solve the problem by syncing the file
283 			 * so that it will have no data structures left.
284 			 */
285 			if ((error = ffs_syncvnode(vp, MNT_WAIT)) != 0)
286 				return (error);
287 			UFS_LOCK(ump);
288 			if (ip->i_flag & IN_SPACECOUNTED)
289 				fs->fs_pendingblocks -= datablocks;
290 			UFS_UNLOCK(ump);
291 		} else {
292 #ifdef QUOTA
293 			(void) chkdq(ip, -datablocks, NOCRED, 0);
294 #endif
295 			softdep_setup_freeblocks(ip, length, needextclean ?
296 			    IO_EXT | IO_NORMAL : IO_NORMAL);
297 			ASSERT_VOP_LOCKED(vp, "ffs_truncate1");
298 			vinvalbuf(vp, needextclean ? 0 : V_NORMAL, 0, 0);
299 			if (!needextclean)
300 				ffs_pages_remove(vp, 0,
301 				    OFF_TO_IDX(lblktosize(fs, -extblocks)));
302 			vnode_pager_setsize(vp, 0);
303 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
304 			return (ffs_update(vp, 0));
305 		}
306 	}
307 	osize = ip->i_size;
308 	/*
309 	 * Lengthen the size of the file. We must ensure that the
310 	 * last byte of the file is allocated. Since the smallest
311 	 * value of osize is 0, length will be at least 1.
312 	 */
313 	if (osize < length) {
314 		vnode_pager_setsize(vp, length);
315 		flags |= BA_CLRBUF;
316 		error = UFS_BALLOC(vp, length - 1, 1, cred, flags, &bp);
317 		if (error) {
318 			vnode_pager_setsize(vp, osize);
319 			return (error);
320 		}
321 		ip->i_size = length;
322 		DIP_SET(ip, i_size, length);
323 		if (bp->b_bufsize == fs->fs_bsize)
324 			bp->b_flags |= B_CLUSTEROK;
325 		if (flags & IO_SYNC)
326 			bwrite(bp);
327 		else
328 			bawrite(bp);
329 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
330 		return (ffs_update(vp, 1));
331 	}
332 	/*
333 	 * Shorten the size of the file. If the file is not being
334 	 * truncated to a block boundary, the contents of the
335 	 * partial block following the end of the file must be
336 	 * zero'ed in case it ever becomes accessible again because
337 	 * of subsequent file growth. Directories however are not
338 	 * zero'ed as they should grow back initialized to empty.
339 	 */
340 	offset = blkoff(fs, length);
341 	if (offset == 0) {
342 		ip->i_size = length;
343 		DIP_SET(ip, i_size, length);
344 	} else {
345 		lbn = lblkno(fs, length);
346 		flags |= BA_CLRBUF;
347 		error = UFS_BALLOC(vp, length - 1, 1, cred, flags, &bp);
348 		if (error) {
349 			return (error);
350 		}
351 		/*
352 		 * When we are doing soft updates and the UFS_BALLOC
353 		 * above fills in a direct block hole with a full sized
354 		 * block that will be truncated down to a fragment below,
355 		 * we must flush out the block dependency with an FSYNC
356 		 * so that we do not get a soft updates inconsistency
357 		 * when we create the fragment below.
358 		 */
359 		if (DOINGSOFTDEP(vp) && lbn < NDADDR &&
360 		    fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize &&
361 		    (error = ffs_syncvnode(vp, MNT_WAIT)) != 0)
362 			return (error);
363 		ip->i_size = length;
364 		DIP_SET(ip, i_size, length);
365 		size = blksize(fs, ip, lbn);
366 		if (vp->v_type != VDIR)
367 			bzero((char *)bp->b_data + offset,
368 			    (u_int)(size - offset));
369 		/* Kirk's code has reallocbuf(bp, size, 1) here */
370 		allocbuf(bp, size);
371 		if (bp->b_bufsize == fs->fs_bsize)
372 			bp->b_flags |= B_CLUSTEROK;
373 		if (flags & IO_SYNC)
374 			bwrite(bp);
375 		else
376 			bawrite(bp);
377 	}
378 	/*
379 	 * Calculate index into inode's block list of
380 	 * last direct and indirect blocks (if any)
381 	 * which we want to keep.  Lastblock is -1 when
382 	 * the file is truncated to 0.
383 	 */
384 	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
385 	lastiblock[SINGLE] = lastblock - NDADDR;
386 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
387 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
388 	nblocks = btodb(fs->fs_bsize);
389 	/*
390 	 * Update file and block pointers on disk before we start freeing
391 	 * blocks.  If we crash before free'ing blocks below, the blocks
392 	 * will be returned to the free list.  lastiblock values are also
393 	 * normalized to -1 for calls to ffs_indirtrunc below.
394 	 */
395 	for (level = TRIPLE; level >= SINGLE; level--) {
396 		oldblks[NDADDR + level] = DIP(ip, i_ib[level]);
397 		if (lastiblock[level] < 0) {
398 			DIP_SET(ip, i_ib[level], 0);
399 			lastiblock[level] = -1;
400 		}
401 	}
402 	for (i = 0; i < NDADDR; i++) {
403 		oldblks[i] = DIP(ip, i_db[i]);
404 		if (i > lastblock)
405 			DIP_SET(ip, i_db[i], 0);
406 	}
407 	ip->i_flag |= IN_CHANGE | IN_UPDATE;
408 	allerror = ffs_update(vp, 1);
409 
410 	/*
411 	 * Having written the new inode to disk, save its new configuration
412 	 * and put back the old block pointers long enough to process them.
413 	 * Note that we save the new block configuration so we can check it
414 	 * when we are done.
415 	 */
416 	for (i = 0; i < NDADDR; i++) {
417 		newblks[i] = DIP(ip, i_db[i]);
418 		DIP_SET(ip, i_db[i], oldblks[i]);
419 	}
420 	for (i = 0; i < NIADDR; i++) {
421 		newblks[NDADDR + i] = DIP(ip, i_ib[i]);
422 		DIP_SET(ip, i_ib[i], oldblks[NDADDR + i]);
423 	}
424 	ip->i_size = osize;
425 	DIP_SET(ip, i_size, osize);
426 
427 	error = vtruncbuf(vp, cred, td, length, fs->fs_bsize);
428 	if (error && (allerror == 0))
429 		allerror = error;
430 
431 	/*
432 	 * Indirect blocks first.
433 	 */
434 	indir_lbn[SINGLE] = -NDADDR;
435 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
436 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
437 	for (level = TRIPLE; level >= SINGLE; level--) {
438 		bn = DIP(ip, i_ib[level]);
439 		if (bn != 0) {
440 			error = ffs_indirtrunc(ip, indir_lbn[level],
441 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
442 			if (error)
443 				allerror = error;
444 			blocksreleased += count;
445 			if (lastiblock[level] < 0) {
446 				DIP_SET(ip, i_ib[level], 0);
447 				ffs_blkfree(ump, fs, ip->i_devvp, bn,
448 				    fs->fs_bsize, ip->i_number);
449 				blocksreleased += nblocks;
450 			}
451 		}
452 		if (lastiblock[level] >= 0)
453 			goto done;
454 	}
455 
456 	/*
457 	 * All whole direct blocks or frags.
458 	 */
459 	for (i = NDADDR - 1; i > lastblock; i--) {
460 		long bsize;
461 
462 		bn = DIP(ip, i_db[i]);
463 		if (bn == 0)
464 			continue;
465 		DIP_SET(ip, i_db[i], 0);
466 		bsize = blksize(fs, ip, i);
467 		ffs_blkfree(ump, fs, ip->i_devvp, bn, bsize, ip->i_number);
468 		blocksreleased += btodb(bsize);
469 	}
470 	if (lastblock < 0)
471 		goto done;
472 
473 	/*
474 	 * Finally, look for a change in size of the
475 	 * last direct block; release any frags.
476 	 */
477 	bn = DIP(ip, i_db[lastblock]);
478 	if (bn != 0) {
479 		long oldspace, newspace;
480 
481 		/*
482 		 * Calculate amount of space we're giving
483 		 * back as old block size minus new block size.
484 		 */
485 		oldspace = blksize(fs, ip, lastblock);
486 		ip->i_size = length;
487 		DIP_SET(ip, i_size, length);
488 		newspace = blksize(fs, ip, lastblock);
489 		if (newspace == 0)
490 			panic("ffs_truncate: newspace");
491 		if (oldspace - newspace > 0) {
492 			/*
493 			 * Block number of space to be free'd is
494 			 * the old block # plus the number of frags
495 			 * required for the storage we're keeping.
496 			 */
497 			bn += numfrags(fs, newspace);
498 			ffs_blkfree(ump, fs, ip->i_devvp, bn,
499 			    oldspace - newspace, ip->i_number);
500 			blocksreleased += btodb(oldspace - newspace);
501 		}
502 	}
503 done:
504 #ifdef INVARIANTS
505 	for (level = SINGLE; level <= TRIPLE; level++)
506 		if (newblks[NDADDR + level] != DIP(ip, i_ib[level]))
507 			panic("ffs_truncate1");
508 	for (i = 0; i < NDADDR; i++)
509 		if (newblks[i] != DIP(ip, i_db[i]))
510 			panic("ffs_truncate2");
511 	BO_LOCK(bo);
512 	if (length == 0 &&
513 	    (fs->fs_magic != FS_UFS2_MAGIC || ip->i_din2->di_extsize == 0) &&
514 	    (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
515 		panic("ffs_truncate3");
516 	BO_UNLOCK(bo);
517 #endif /* INVARIANTS */
518 	/*
519 	 * Put back the real size.
520 	 */
521 	ip->i_size = length;
522 	DIP_SET(ip, i_size, length);
523 	DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - blocksreleased);
524 
525 	if (DIP(ip, i_blocks) < 0)			/* sanity */
526 		DIP_SET(ip, i_blocks, 0);
527 	ip->i_flag |= IN_CHANGE;
528 #ifdef QUOTA
529 	(void) chkdq(ip, -blocksreleased, NOCRED, 0);
530 #endif
531 	return (allerror);
532 }
533 
534 /*
535  * Release blocks associated with the inode ip and stored in the indirect
536  * block bn.  Blocks are free'd in LIFO order up to (but not including)
537  * lastbn.  If level is greater than SINGLE, the block is an indirect block
538  * and recursive calls to indirtrunc must be used to cleanse other indirect
539  * blocks.
540  */
541 static int
542 ffs_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
543 	struct inode *ip;
544 	ufs2_daddr_t lbn, lastbn;
545 	ufs2_daddr_t dbn;
546 	int level;
547 	ufs2_daddr_t *countp;
548 {
549 	struct buf *bp;
550 	struct fs *fs = ip->i_fs;
551 	struct vnode *vp;
552 	caddr_t copy = NULL;
553 	int i, nblocks, error = 0, allerror = 0;
554 	ufs2_daddr_t nb, nlbn, last;
555 	ufs2_daddr_t blkcount, factor, blocksreleased = 0;
556 	ufs1_daddr_t *bap1 = NULL;
557 	ufs2_daddr_t *bap2 = NULL;
558 #	define BAP(ip, i) (((ip)->i_ump->um_fstype == UFS1) ? bap1[i] : bap2[i])
559 
560 	/*
561 	 * Calculate index in current block of last
562 	 * block to be kept.  -1 indicates the entire
563 	 * block so we need not calculate the index.
564 	 */
565 	factor = 1;
566 	for (i = SINGLE; i < level; i++)
567 		factor *= NINDIR(fs);
568 	last = lastbn;
569 	if (lastbn > 0)
570 		last /= factor;
571 	nblocks = btodb(fs->fs_bsize);
572 	/*
573 	 * Get buffer of block pointers, zero those entries corresponding
574 	 * to blocks to be free'd, and update on disk copy first.  Since
575 	 * double(triple) indirect before single(double) indirect, calls
576 	 * to bmap on these blocks will fail.  However, we already have
577 	 * the on disk address, so we have to set the b_blkno field
578 	 * explicitly instead of letting bread do everything for us.
579 	 */
580 	vp = ITOV(ip);
581 	bp = getblk(vp, lbn, (int)fs->fs_bsize, 0, 0, 0);
582 	if ((bp->b_flags & B_CACHE) == 0) {
583 		curthread->td_ru.ru_inblock++;	/* pay for read */
584 		bp->b_iocmd = BIO_READ;
585 		bp->b_flags &= ~B_INVAL;
586 		bp->b_ioflags &= ~BIO_ERROR;
587 		if (bp->b_bcount > bp->b_bufsize)
588 			panic("ffs_indirtrunc: bad buffer size");
589 		bp->b_blkno = dbn;
590 		vfs_busy_pages(bp, 0);
591 		bp->b_iooffset = dbtob(bp->b_blkno);
592 		bstrategy(bp);
593 		error = bufwait(bp);
594 	}
595 	if (error) {
596 		brelse(bp);
597 		*countp = 0;
598 		return (error);
599 	}
600 
601 	if (ip->i_ump->um_fstype == UFS1)
602 		bap1 = (ufs1_daddr_t *)bp->b_data;
603 	else
604 		bap2 = (ufs2_daddr_t *)bp->b_data;
605 	if (lastbn != -1) {
606 		copy = malloc(fs->fs_bsize, M_TEMP, M_WAITOK);
607 		bcopy((caddr_t)bp->b_data, copy, (u_int)fs->fs_bsize);
608 		for (i = last + 1; i < NINDIR(fs); i++)
609 			if (ip->i_ump->um_fstype == UFS1)
610 				bap1[i] = 0;
611 			else
612 				bap2[i] = 0;
613 		if (DOINGASYNC(vp)) {
614 			bawrite(bp);
615 		} else {
616 			error = bwrite(bp);
617 			if (error)
618 				allerror = error;
619 		}
620 		if (ip->i_ump->um_fstype == UFS1)
621 			bap1 = (ufs1_daddr_t *)copy;
622 		else
623 			bap2 = (ufs2_daddr_t *)copy;
624 	}
625 
626 	/*
627 	 * Recursively free totally unused blocks.
628 	 */
629 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
630 	    i--, nlbn += factor) {
631 		nb = BAP(ip, i);
632 		if (nb == 0)
633 			continue;
634 		if (level > SINGLE) {
635 			if ((error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
636 			    (ufs2_daddr_t)-1, level - 1, &blkcount)) != 0)
637 				allerror = error;
638 			blocksreleased += blkcount;
639 		}
640 		ffs_blkfree(ip->i_ump, fs, ip->i_devvp, nb, fs->fs_bsize,
641 		    ip->i_number);
642 		blocksreleased += nblocks;
643 	}
644 
645 	/*
646 	 * Recursively free last partial block.
647 	 */
648 	if (level > SINGLE && lastbn >= 0) {
649 		last = lastbn % factor;
650 		nb = BAP(ip, i);
651 		if (nb != 0) {
652 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
653 			    last, level - 1, &blkcount);
654 			if (error)
655 				allerror = error;
656 			blocksreleased += blkcount;
657 		}
658 	}
659 	if (copy != NULL) {
660 		free(copy, M_TEMP);
661 	} else {
662 		bp->b_flags |= B_INVAL | B_NOCACHE;
663 		brelse(bp);
664 	}
665 
666 	*countp = blocksreleased;
667 	return (allerror);
668 }
669 
670 int
671 ffs_rdonly(struct inode *ip)
672 {
673 
674 	return (ip->i_ump->um_fs->fs_ronly != 0);
675 }
676 
677