xref: /freebsd/sys/ufs/ffs/ffs_inode.c (revision 11b249f99e4d4891bd2a21ef796d40073ee15508)
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/bio.h>
40 #include <sys/buf.h>
41 #include <sys/malloc.h>
42 #include <sys/mount.h>
43 #include <sys/proc.h>
44 #include <sys/random.h>
45 #include <sys/resourcevar.h>
46 #include <sys/rwlock.h>
47 #include <sys/stat.h>
48 #include <sys/vmmeter.h>
49 #include <sys/vnode.h>
50 
51 #include <vm/vm.h>
52 #include <vm/vm_extern.h>
53 #include <vm/vm_object.h>
54 
55 #include <ufs/ufs/extattr.h>
56 #include <ufs/ufs/quota.h>
57 #include <ufs/ufs/ufsmount.h>
58 #include <ufs/ufs/inode.h>
59 #include <ufs/ufs/ufs_extern.h>
60 
61 #include <ufs/ffs/fs.h>
62 #include <ufs/ffs/ffs_extern.h>
63 
64 static int ffs_indirtrunc(struct inode *, ufs2_daddr_t, ufs2_daddr_t,
65 	    ufs2_daddr_t, int, ufs2_daddr_t *);
66 
67 /*
68  * Update the access, modified, and inode change times as specified by the
69  * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
70  * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
71  * the timestamp update).  The IN_LAZYMOD flag is set to force a write
72  * later if not now.  The IN_LAZYACCESS is set instead of IN_MODIFIED if the fs
73  * is currently being suspended (or is suspended) and vnode has been accessed.
74  * If we write now, then clear IN_MODIFIED, IN_LAZYACCESS and IN_LAZYMOD to
75  * reflect the presumably successful write, and if waitfor is set, then wait
76  * for the write to complete.
77  */
78 int
79 ffs_update(vp, waitfor)
80 	struct vnode *vp;
81 	int waitfor;
82 {
83 	struct fs *fs;
84 	struct buf *bp;
85 	struct inode *ip;
86 	int flags, error;
87 
88 	ASSERT_VOP_ELOCKED(vp, "ffs_update");
89 	ufs_itimes(vp);
90 	ip = VTOI(vp);
91 	if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
92 		return (0);
93 	ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED);
94 	fs = ip->i_fs;
95 	if (fs->fs_ronly && ip->i_ump->um_fsckpid == 0)
96 		return (0);
97 	/*
98 	 * If we are updating a snapshot and another process is currently
99 	 * writing the buffer containing the inode for this snapshot then
100 	 * a deadlock can occur when it tries to check the snapshot to see
101 	 * if that block needs to be copied. Thus when updating a snapshot
102 	 * we check to see if the buffer is already locked, and if it is
103 	 * we drop the snapshot lock until the buffer has been written
104 	 * and is available to us. We have to grab a reference to the
105 	 * snapshot vnode to prevent it from being removed while we are
106 	 * waiting for the buffer.
107 	 */
108 	flags = 0;
109 	if (IS_SNAPSHOT(ip))
110 		flags = GB_LOCK_NOWAIT;
111 loop:
112 	error = breadn_flags(ip->i_devvp,
113 	     fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
114 	     (int) fs->fs_bsize, 0, 0, 0, NOCRED, flags, &bp);
115 	if (error != 0) {
116 		if (error != EBUSY) {
117 			brelse(bp);
118 			return (error);
119 		}
120 		KASSERT((IS_SNAPSHOT(ip)), ("EBUSY from non-snapshot"));
121 		/*
122 		 * Wait for our inode block to become available.
123 		 *
124 		 * Hold a reference to the vnode to protect against
125 		 * ffs_snapgone(). Since we hold a reference, it can only
126 		 * get reclaimed (VI_DOOMED flag) in a forcible downgrade
127 		 * or unmount. For an unmount, the entire filesystem will be
128 		 * gone, so we cannot attempt to touch anything associated
129 		 * with it while the vnode is unlocked; all we can do is
130 		 * pause briefly and try again. If when we relock the vnode
131 		 * we discover that it has been reclaimed, updating it is no
132 		 * longer necessary and we can just return an error.
133 		 */
134 		vref(vp);
135 		VOP_UNLOCK(vp, 0);
136 		pause("ffsupd", 1);
137 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
138 		vrele(vp);
139 		if ((vp->v_iflag & VI_DOOMED) != 0)
140 			return (ENOENT);
141 		goto loop;
142 	}
143 	if (DOINGSOFTDEP(vp))
144 		softdep_update_inodeblock(ip, bp, waitfor);
145 	else if (ip->i_effnlink != ip->i_nlink)
146 		panic("ffs_update: bad link cnt");
147 	if (ip->i_ump->um_fstype == UFS1) {
148 		*((struct ufs1_dinode *)bp->b_data +
149 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din1;
150 		/* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
151 		random_harvest_queue(&(ip->i_din1), sizeof(ip->i_din1), 1, RANDOM_FS_ATIME);
152 	} else {
153 		*((struct ufs2_dinode *)bp->b_data +
154 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din2;
155 		/* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
156 		random_harvest_queue(&(ip->i_din2), sizeof(ip->i_din2), 1, RANDOM_FS_ATIME);
157 	}
158 	if (waitfor && !DOINGASYNC(vp))
159 		error = bwrite(bp);
160 	else if (vm_page_count_severe() || buf_dirty_count_severe()) {
161 		bawrite(bp);
162 		error = 0;
163 	} else {
164 		if (bp->b_bufsize == fs->fs_bsize)
165 			bp->b_flags |= B_CLUSTEROK;
166 		bdwrite(bp);
167 		error = 0;
168 	}
169 	return (error);
170 }
171 
172 #define	SINGLE	0	/* index of single indirect block */
173 #define	DOUBLE	1	/* index of double indirect block */
174 #define	TRIPLE	2	/* index of triple indirect block */
175 /*
176  * Truncate the inode ip to at most length size, freeing the
177  * disk blocks.
178  */
179 int
180 ffs_truncate(vp, length, flags, cred)
181 	struct vnode *vp;
182 	off_t length;
183 	int flags;
184 	struct ucred *cred;
185 {
186 	struct inode *ip;
187 	ufs2_daddr_t bn, lbn, lastblock, lastiblock[NIADDR], indir_lbn[NIADDR];
188 	ufs2_daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
189 	ufs2_daddr_t count, blocksreleased = 0, datablocks;
190 	struct bufobj *bo;
191 	struct fs *fs;
192 	struct buf *bp;
193 	struct ufsmount *ump;
194 	int softdeptrunc, journaltrunc;
195 	int needextclean, extblocks;
196 	int offset, size, level, nblocks;
197 	int i, error, allerror;
198 	off_t osize;
199 
200 	ip = VTOI(vp);
201 	fs = ip->i_fs;
202 	ump = ip->i_ump;
203 	bo = &vp->v_bufobj;
204 
205 	ASSERT_VOP_LOCKED(vp, "ffs_truncate");
206 
207 	if (length < 0)
208 		return (EINVAL);
209 	if (length > fs->fs_maxfilesize)
210 		return (EFBIG);
211 #ifdef QUOTA
212 	error = getinoquota(ip);
213 	if (error)
214 		return (error);
215 #endif
216 	/*
217 	 * Historically clients did not have to specify which data
218 	 * they were truncating. So, if not specified, we assume
219 	 * traditional behavior, e.g., just the normal data.
220 	 */
221 	if ((flags & (IO_EXT | IO_NORMAL)) == 0)
222 		flags |= IO_NORMAL;
223 	if (!DOINGSOFTDEP(vp) && !DOINGASYNC(vp))
224 		flags |= IO_SYNC;
225 	/*
226 	 * If we are truncating the extended-attributes, and cannot
227 	 * do it with soft updates, then do it slowly here. If we are
228 	 * truncating both the extended attributes and the file contents
229 	 * (e.g., the file is being unlinked), then pick it off with
230 	 * soft updates below.
231 	 */
232 	allerror = 0;
233 	needextclean = 0;
234 	softdeptrunc = 0;
235 	journaltrunc = DOINGSUJ(vp);
236 	if (journaltrunc == 0 && DOINGSOFTDEP(vp) && length == 0)
237 		softdeptrunc = !softdep_slowdown(vp);
238 	extblocks = 0;
239 	datablocks = DIP(ip, i_blocks);
240 	if (fs->fs_magic == FS_UFS2_MAGIC && ip->i_din2->di_extsize > 0) {
241 		extblocks = btodb(fragroundup(fs, ip->i_din2->di_extsize));
242 		datablocks -= extblocks;
243 	}
244 	if ((flags & IO_EXT) && extblocks > 0) {
245 		if (length != 0)
246 			panic("ffs_truncate: partial trunc of extdata");
247 		if (softdeptrunc || journaltrunc) {
248 			if ((flags & IO_NORMAL) == 0)
249 				goto extclean;
250 			needextclean = 1;
251 		} else {
252 			if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0)
253 				return (error);
254 #ifdef QUOTA
255 			(void) chkdq(ip, -extblocks, NOCRED, 0);
256 #endif
257 			vinvalbuf(vp, V_ALT, 0, 0);
258 			vn_pages_remove(vp,
259 			    OFF_TO_IDX(lblktosize(fs, -extblocks)), 0);
260 			osize = ip->i_din2->di_extsize;
261 			ip->i_din2->di_blocks -= extblocks;
262 			ip->i_din2->di_extsize = 0;
263 			for (i = 0; i < NXADDR; i++) {
264 				oldblks[i] = ip->i_din2->di_extb[i];
265 				ip->i_din2->di_extb[i] = 0;
266 			}
267 			ip->i_flag |= IN_CHANGE;
268 			if ((error = ffs_update(vp, !DOINGASYNC(vp))))
269 				return (error);
270 			for (i = 0; i < NXADDR; i++) {
271 				if (oldblks[i] == 0)
272 					continue;
273 				ffs_blkfree(ump, fs, ip->i_devvp, oldblks[i],
274 				    sblksize(fs, osize, i), ip->i_number,
275 				    vp->v_type, NULL);
276 			}
277 		}
278 	}
279 	if ((flags & IO_NORMAL) == 0)
280 		return (0);
281 	if (vp->v_type == VLNK &&
282 	    (ip->i_size < vp->v_mount->mnt_maxsymlinklen ||
283 	     datablocks == 0)) {
284 #ifdef INVARIANTS
285 		if (length != 0)
286 			panic("ffs_truncate: partial truncate of symlink");
287 #endif
288 		bzero(SHORTLINK(ip), (u_int)ip->i_size);
289 		ip->i_size = 0;
290 		DIP_SET(ip, i_size, 0);
291 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
292 		if (needextclean)
293 			goto extclean;
294 		return (ffs_update(vp, !DOINGASYNC(vp)));
295 	}
296 	if (ip->i_size == length) {
297 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
298 		if (needextclean)
299 			goto extclean;
300 		return (ffs_update(vp, 0));
301 	}
302 	if (fs->fs_ronly)
303 		panic("ffs_truncate: read-only filesystem");
304 	if (IS_SNAPSHOT(ip))
305 		ffs_snapremove(vp);
306 	vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
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 if (DOINGASYNC(vp))
328 			bdwrite(bp);
329 		else
330 			bawrite(bp);
331 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
332 		return (ffs_update(vp, !DOINGASYNC(vp)));
333 	}
334 	if (DOINGSOFTDEP(vp)) {
335 		if (softdeptrunc == 0 && journaltrunc == 0) {
336 			/*
337 			 * If a file is only partially truncated, then
338 			 * we have to clean up the data structures
339 			 * describing the allocation past the truncation
340 			 * point. Finding and deallocating those structures
341 			 * is a lot of work. Since partial truncation occurs
342 			 * rarely, we solve the problem by syncing the file
343 			 * so that it will have no data structures left.
344 			 */
345 			if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0)
346 				return (error);
347 		} else {
348 			flags = IO_NORMAL | (needextclean ? IO_EXT: 0);
349 			if (journaltrunc)
350 				softdep_journal_freeblocks(ip, cred, length,
351 				    flags);
352 			else
353 				softdep_setup_freeblocks(ip, length, flags);
354 			ASSERT_VOP_LOCKED(vp, "ffs_truncate1");
355 			if (journaltrunc == 0) {
356 				ip->i_flag |= IN_CHANGE | IN_UPDATE;
357 				error = ffs_update(vp, 0);
358 			}
359 			return (error);
360 		}
361 	}
362 	/*
363 	 * Shorten the size of the file. If the file is not being
364 	 * truncated to a block boundary, the contents of the
365 	 * partial block following the end of the file must be
366 	 * zero'ed in case it ever becomes accessible again because
367 	 * of subsequent file growth. Directories however are not
368 	 * zero'ed as they should grow back initialized to empty.
369 	 */
370 	offset = blkoff(fs, length);
371 	if (offset == 0) {
372 		ip->i_size = length;
373 		DIP_SET(ip, i_size, length);
374 	} else {
375 		lbn = lblkno(fs, length);
376 		flags |= BA_CLRBUF;
377 		error = UFS_BALLOC(vp, length - 1, 1, cred, flags, &bp);
378 		if (error)
379 			return (error);
380 		/*
381 		 * When we are doing soft updates and the UFS_BALLOC
382 		 * above fills in a direct block hole with a full sized
383 		 * block that will be truncated down to a fragment below,
384 		 * we must flush out the block dependency with an FSYNC
385 		 * so that we do not get a soft updates inconsistency
386 		 * when we create the fragment below.
387 		 */
388 		if (DOINGSOFTDEP(vp) && lbn < NDADDR &&
389 		    fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize &&
390 		    (error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0)
391 			return (error);
392 		ip->i_size = length;
393 		DIP_SET(ip, i_size, length);
394 		size = blksize(fs, ip, lbn);
395 		if (vp->v_type != VDIR)
396 			bzero((char *)bp->b_data + offset,
397 			    (u_int)(size - offset));
398 		/* Kirk's code has reallocbuf(bp, size, 1) here */
399 		allocbuf(bp, size);
400 		if (bp->b_bufsize == fs->fs_bsize)
401 			bp->b_flags |= B_CLUSTEROK;
402 		if (flags & IO_SYNC)
403 			bwrite(bp);
404 		else if (DOINGASYNC(vp))
405 			bdwrite(bp);
406 		else
407 			bawrite(bp);
408 	}
409 	/*
410 	 * Calculate index into inode's block list of
411 	 * last direct and indirect blocks (if any)
412 	 * which we want to keep.  Lastblock is -1 when
413 	 * the file is truncated to 0.
414 	 */
415 	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
416 	lastiblock[SINGLE] = lastblock - NDADDR;
417 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
418 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
419 	nblocks = btodb(fs->fs_bsize);
420 	/*
421 	 * Update file and block pointers on disk before we start freeing
422 	 * blocks.  If we crash before free'ing blocks below, the blocks
423 	 * will be returned to the free list.  lastiblock values are also
424 	 * normalized to -1 for calls to ffs_indirtrunc below.
425 	 */
426 	for (level = TRIPLE; level >= SINGLE; level--) {
427 		oldblks[NDADDR + level] = DIP(ip, i_ib[level]);
428 		if (lastiblock[level] < 0) {
429 			DIP_SET(ip, i_ib[level], 0);
430 			lastiblock[level] = -1;
431 		}
432 	}
433 	for (i = 0; i < NDADDR; i++) {
434 		oldblks[i] = DIP(ip, i_db[i]);
435 		if (i > lastblock)
436 			DIP_SET(ip, i_db[i], 0);
437 	}
438 	ip->i_flag |= IN_CHANGE | IN_UPDATE;
439 	allerror = ffs_update(vp, !DOINGASYNC(vp));
440 
441 	/*
442 	 * Having written the new inode to disk, save its new configuration
443 	 * and put back the old block pointers long enough to process them.
444 	 * Note that we save the new block configuration so we can check it
445 	 * when we are done.
446 	 */
447 	for (i = 0; i < NDADDR; i++) {
448 		newblks[i] = DIP(ip, i_db[i]);
449 		DIP_SET(ip, i_db[i], oldblks[i]);
450 	}
451 	for (i = 0; i < NIADDR; i++) {
452 		newblks[NDADDR + i] = DIP(ip, i_ib[i]);
453 		DIP_SET(ip, i_ib[i], oldblks[NDADDR + i]);
454 	}
455 	ip->i_size = osize;
456 	DIP_SET(ip, i_size, osize);
457 
458 	error = vtruncbuf(vp, cred, length, fs->fs_bsize);
459 	if (error && (allerror == 0))
460 		allerror = error;
461 
462 	/*
463 	 * Indirect blocks first.
464 	 */
465 	indir_lbn[SINGLE] = -NDADDR;
466 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
467 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
468 	for (level = TRIPLE; level >= SINGLE; level--) {
469 		bn = DIP(ip, i_ib[level]);
470 		if (bn != 0) {
471 			error = ffs_indirtrunc(ip, indir_lbn[level],
472 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
473 			if (error)
474 				allerror = error;
475 			blocksreleased += count;
476 			if (lastiblock[level] < 0) {
477 				DIP_SET(ip, i_ib[level], 0);
478 				ffs_blkfree(ump, fs, ip->i_devvp, bn,
479 				    fs->fs_bsize, ip->i_number,
480 				    vp->v_type, NULL);
481 				blocksreleased += nblocks;
482 			}
483 		}
484 		if (lastiblock[level] >= 0)
485 			goto done;
486 	}
487 
488 	/*
489 	 * All whole direct blocks or frags.
490 	 */
491 	for (i = NDADDR - 1; i > lastblock; i--) {
492 		long bsize;
493 
494 		bn = DIP(ip, i_db[i]);
495 		if (bn == 0)
496 			continue;
497 		DIP_SET(ip, i_db[i], 0);
498 		bsize = blksize(fs, ip, i);
499 		ffs_blkfree(ump, fs, ip->i_devvp, bn, bsize, ip->i_number,
500 		    vp->v_type, NULL);
501 		blocksreleased += btodb(bsize);
502 	}
503 	if (lastblock < 0)
504 		goto done;
505 
506 	/*
507 	 * Finally, look for a change in size of the
508 	 * last direct block; release any frags.
509 	 */
510 	bn = DIP(ip, i_db[lastblock]);
511 	if (bn != 0) {
512 		long oldspace, newspace;
513 
514 		/*
515 		 * Calculate amount of space we're giving
516 		 * back as old block size minus new block size.
517 		 */
518 		oldspace = blksize(fs, ip, lastblock);
519 		ip->i_size = length;
520 		DIP_SET(ip, i_size, length);
521 		newspace = blksize(fs, ip, lastblock);
522 		if (newspace == 0)
523 			panic("ffs_truncate: newspace");
524 		if (oldspace - newspace > 0) {
525 			/*
526 			 * Block number of space to be free'd is
527 			 * the old block # plus the number of frags
528 			 * required for the storage we're keeping.
529 			 */
530 			bn += numfrags(fs, newspace);
531 			ffs_blkfree(ump, fs, ip->i_devvp, bn,
532 			   oldspace - newspace, ip->i_number, vp->v_type, NULL);
533 			blocksreleased += btodb(oldspace - newspace);
534 		}
535 	}
536 done:
537 #ifdef INVARIANTS
538 	for (level = SINGLE; level <= TRIPLE; level++)
539 		if (newblks[NDADDR + level] != DIP(ip, i_ib[level]))
540 			panic("ffs_truncate1");
541 	for (i = 0; i < NDADDR; i++)
542 		if (newblks[i] != DIP(ip, i_db[i]))
543 			panic("ffs_truncate2");
544 	BO_LOCK(bo);
545 	if (length == 0 &&
546 	    (fs->fs_magic != FS_UFS2_MAGIC || ip->i_din2->di_extsize == 0) &&
547 	    (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
548 		panic("ffs_truncate3");
549 	BO_UNLOCK(bo);
550 #endif /* INVARIANTS */
551 	/*
552 	 * Put back the real size.
553 	 */
554 	ip->i_size = length;
555 	DIP_SET(ip, i_size, length);
556 	if (DIP(ip, i_blocks) >= blocksreleased)
557 		DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - blocksreleased);
558 	else	/* sanity */
559 		DIP_SET(ip, i_blocks, 0);
560 	ip->i_flag |= IN_CHANGE;
561 #ifdef QUOTA
562 	(void) chkdq(ip, -blocksreleased, NOCRED, 0);
563 #endif
564 	return (allerror);
565 
566 extclean:
567 	if (journaltrunc)
568 		softdep_journal_freeblocks(ip, cred, length, IO_EXT);
569 	else
570 		softdep_setup_freeblocks(ip, length, IO_EXT);
571 	return (ffs_update(vp, !DOINGASYNC(vp)));
572 }
573 
574 /*
575  * Release blocks associated with the inode ip and stored in the indirect
576  * block bn.  Blocks are free'd in LIFO order up to (but not including)
577  * lastbn.  If level is greater than SINGLE, the block is an indirect block
578  * and recursive calls to indirtrunc must be used to cleanse other indirect
579  * blocks.
580  */
581 static int
582 ffs_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
583 	struct inode *ip;
584 	ufs2_daddr_t lbn, lastbn;
585 	ufs2_daddr_t dbn;
586 	int level;
587 	ufs2_daddr_t *countp;
588 {
589 	struct buf *bp;
590 	struct fs *fs = ip->i_fs;
591 	struct vnode *vp;
592 	caddr_t copy = NULL;
593 	int i, nblocks, error = 0, allerror = 0;
594 	ufs2_daddr_t nb, nlbn, last;
595 	ufs2_daddr_t blkcount, factor, blocksreleased = 0;
596 	ufs1_daddr_t *bap1 = NULL;
597 	ufs2_daddr_t *bap2 = NULL;
598 #	define BAP(ip, i) (((ip)->i_ump->um_fstype == UFS1) ? bap1[i] : bap2[i])
599 
600 	/*
601 	 * Calculate index in current block of last
602 	 * block to be kept.  -1 indicates the entire
603 	 * block so we need not calculate the index.
604 	 */
605 	factor = lbn_offset(fs, level);
606 	last = lastbn;
607 	if (lastbn > 0)
608 		last /= factor;
609 	nblocks = btodb(fs->fs_bsize);
610 	/*
611 	 * Get buffer of block pointers, zero those entries corresponding
612 	 * to blocks to be free'd, and update on disk copy first.  Since
613 	 * double(triple) indirect before single(double) indirect, calls
614 	 * to bmap on these blocks will fail.  However, we already have
615 	 * the on disk address, so we have to set the b_blkno field
616 	 * explicitly instead of letting bread do everything for us.
617 	 */
618 	vp = ITOV(ip);
619 	bp = getblk(vp, lbn, (int)fs->fs_bsize, 0, 0, 0);
620 	if ((bp->b_flags & B_CACHE) == 0) {
621 		curthread->td_ru.ru_inblock++;	/* pay for read */
622 		bp->b_iocmd = BIO_READ;
623 		bp->b_flags &= ~B_INVAL;
624 		bp->b_ioflags &= ~BIO_ERROR;
625 		if (bp->b_bcount > bp->b_bufsize)
626 			panic("ffs_indirtrunc: bad buffer size");
627 		bp->b_blkno = dbn;
628 		vfs_busy_pages(bp, 0);
629 		bp->b_iooffset = dbtob(bp->b_blkno);
630 		bstrategy(bp);
631 		error = bufwait(bp);
632 	}
633 	if (error) {
634 		brelse(bp);
635 		*countp = 0;
636 		return (error);
637 	}
638 
639 	if (ip->i_ump->um_fstype == UFS1)
640 		bap1 = (ufs1_daddr_t *)bp->b_data;
641 	else
642 		bap2 = (ufs2_daddr_t *)bp->b_data;
643 	if (lastbn != -1) {
644 		copy = malloc(fs->fs_bsize, M_TEMP, M_WAITOK);
645 		bcopy((caddr_t)bp->b_data, copy, (u_int)fs->fs_bsize);
646 		for (i = last + 1; i < NINDIR(fs); i++)
647 			if (ip->i_ump->um_fstype == UFS1)
648 				bap1[i] = 0;
649 			else
650 				bap2[i] = 0;
651 		if (DOINGASYNC(vp)) {
652 			bdwrite(bp);
653 		} else {
654 			error = bwrite(bp);
655 			if (error)
656 				allerror = error;
657 		}
658 		if (ip->i_ump->um_fstype == UFS1)
659 			bap1 = (ufs1_daddr_t *)copy;
660 		else
661 			bap2 = (ufs2_daddr_t *)copy;
662 	}
663 
664 	/*
665 	 * Recursively free totally unused blocks.
666 	 */
667 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
668 	    i--, nlbn += factor) {
669 		nb = BAP(ip, i);
670 		if (nb == 0)
671 			continue;
672 		if (level > SINGLE) {
673 			if ((error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
674 			    (ufs2_daddr_t)-1, level - 1, &blkcount)) != 0)
675 				allerror = error;
676 			blocksreleased += blkcount;
677 		}
678 		ffs_blkfree(ip->i_ump, fs, ip->i_devvp, nb, fs->fs_bsize,
679 		    ip->i_number, vp->v_type, NULL);
680 		blocksreleased += nblocks;
681 	}
682 
683 	/*
684 	 * Recursively free last partial block.
685 	 */
686 	if (level > SINGLE && lastbn >= 0) {
687 		last = lastbn % factor;
688 		nb = BAP(ip, i);
689 		if (nb != 0) {
690 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
691 			    last, level - 1, &blkcount);
692 			if (error)
693 				allerror = error;
694 			blocksreleased += blkcount;
695 		}
696 	}
697 	if (copy != NULL) {
698 		free(copy, M_TEMP);
699 	} else {
700 		bp->b_flags |= B_INVAL | B_NOCACHE;
701 		brelse(bp);
702 	}
703 
704 	*countp = blocksreleased;
705 	return (allerror);
706 }
707 
708 int
709 ffs_rdonly(struct inode *ip)
710 {
711 
712 	return (ip->i_ump->um_fs->fs_ronly != 0);
713 }
714 
715