xref: /freebsd/sys/ufs/ffs/ffs_inode.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
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 && ip->i_ump->um_fsckpid == 0)
94 		return (0);
95 	error = bread(ip->i_devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
96 		(int)fs->fs_bsize, NOCRED, &bp);
97 	if (error) {
98 		brelse(bp);
99 		return (error);
100 	}
101 	if (DOINGSOFTDEP(vp))
102 		softdep_update_inodeblock(ip, bp, waitfor);
103 	else if (ip->i_effnlink != ip->i_nlink)
104 		panic("ffs_update: bad link cnt");
105 	if (ip->i_ump->um_fstype == UFS1)
106 		*((struct ufs1_dinode *)bp->b_data +
107 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din1;
108 	else
109 		*((struct ufs2_dinode *)bp->b_data +
110 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din2;
111 	if (waitfor && !DOINGASYNC(vp)) {
112 		return (bwrite(bp));
113 	} else if (vm_page_count_severe() || buf_dirty_count_severe()) {
114 		return (bwrite(bp));
115 	} else {
116 		if (bp->b_bufsize == fs->fs_bsize)
117 			bp->b_flags |= B_CLUSTEROK;
118 		bdwrite(bp);
119 		return (0);
120 	}
121 }
122 
123 #define	SINGLE	0	/* index of single indirect block */
124 #define	DOUBLE	1	/* index of double indirect block */
125 #define	TRIPLE	2	/* index of triple indirect block */
126 /*
127  * Truncate the inode ip to at most length size, freeing the
128  * disk blocks.
129  */
130 int
131 ffs_truncate(vp, length, flags, cred, td)
132 	struct vnode *vp;
133 	off_t length;
134 	int flags;
135 	struct ucred *cred;
136 	struct thread *td;
137 {
138 	struct inode *ip;
139 	ufs2_daddr_t bn, lbn, lastblock, lastiblock[NIADDR], indir_lbn[NIADDR];
140 	ufs2_daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
141 	ufs2_daddr_t count, blocksreleased = 0, datablocks;
142 	struct bufobj *bo;
143 	struct fs *fs;
144 	struct buf *bp;
145 	struct ufsmount *ump;
146 	int softdeptrunc, journaltrunc;
147 	int needextclean, extblocks;
148 	int offset, size, level, nblocks;
149 	int i, error, allerror;
150 	off_t osize;
151 
152 	ip = VTOI(vp);
153 	fs = ip->i_fs;
154 	ump = ip->i_ump;
155 	bo = &vp->v_bufobj;
156 
157 	ASSERT_VOP_LOCKED(vp, "ffs_truncate");
158 
159 	if (length < 0)
160 		return (EINVAL);
161 	if (length > fs->fs_maxfilesize)
162 		return (EFBIG);
163 #ifdef QUOTA
164 	error = getinoquota(ip);
165 	if (error)
166 		return (error);
167 #endif
168 	/*
169 	 * Historically clients did not have to specify which data
170 	 * they were truncating. So, if not specified, we assume
171 	 * traditional behavior, e.g., just the normal data.
172 	 */
173 	if ((flags & (IO_EXT | IO_NORMAL)) == 0)
174 		flags |= IO_NORMAL;
175 	if (!DOINGSOFTDEP(vp) && !DOINGASYNC(vp))
176 		flags |= IO_SYNC;
177 	/*
178 	 * If we are truncating the extended-attributes, and cannot
179 	 * do it with soft updates, then do it slowly here. If we are
180 	 * truncating both the extended attributes and the file contents
181 	 * (e.g., the file is being unlinked), then pick it off with
182 	 * soft updates below.
183 	 */
184 	allerror = 0;
185 	needextclean = 0;
186 	softdeptrunc = 0;
187 	journaltrunc = DOINGSUJ(vp);
188 	if (journaltrunc == 0 && DOINGSOFTDEP(vp) && length == 0)
189 		softdeptrunc = !softdep_slowdown(vp);
190 	extblocks = 0;
191 	datablocks = DIP(ip, i_blocks);
192 	if (fs->fs_magic == FS_UFS2_MAGIC && ip->i_din2->di_extsize > 0) {
193 		extblocks = btodb(fragroundup(fs, ip->i_din2->di_extsize));
194 		datablocks -= extblocks;
195 	}
196 	if ((flags & IO_EXT) && extblocks > 0) {
197 		if (length != 0)
198 			panic("ffs_truncate: partial trunc of extdata");
199 		if (softdeptrunc || journaltrunc) {
200 			if ((flags & IO_NORMAL) == 0)
201 				goto extclean;
202 			needextclean = 1;
203 		} else {
204 			if ((error = ffs_syncvnode(vp, MNT_WAIT)) != 0)
205 				return (error);
206 #ifdef QUOTA
207 			(void) chkdq(ip, -extblocks, NOCRED, 0);
208 #endif
209 			vinvalbuf(vp, V_ALT, 0, 0);
210 			vn_pages_remove(vp,
211 			    OFF_TO_IDX(lblktosize(fs, -extblocks)), 0);
212 			osize = ip->i_din2->di_extsize;
213 			ip->i_din2->di_blocks -= extblocks;
214 			ip->i_din2->di_extsize = 0;
215 			for (i = 0; i < NXADDR; i++) {
216 				oldblks[i] = ip->i_din2->di_extb[i];
217 				ip->i_din2->di_extb[i] = 0;
218 			}
219 			ip->i_flag |= IN_CHANGE;
220 			if ((error = ffs_update(vp, 1)))
221 				return (error);
222 			for (i = 0; i < NXADDR; i++) {
223 				if (oldblks[i] == 0)
224 					continue;
225 				ffs_blkfree(ump, fs, ip->i_devvp, oldblks[i],
226 				    sblksize(fs, osize, i), ip->i_number,
227 				    vp->v_type, NULL);
228 			}
229 		}
230 	}
231 	if ((flags & IO_NORMAL) == 0)
232 		return (0);
233 	if (vp->v_type == VLNK &&
234 	    (ip->i_size < vp->v_mount->mnt_maxsymlinklen ||
235 	     datablocks == 0)) {
236 #ifdef INVARIANTS
237 		if (length != 0)
238 			panic("ffs_truncate: partial truncate of symlink");
239 #endif
240 		bzero(SHORTLINK(ip), (u_int)ip->i_size);
241 		ip->i_size = 0;
242 		DIP_SET(ip, i_size, 0);
243 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
244 		if (needextclean)
245 			goto extclean;
246 		return ffs_update(vp, 1);
247 	}
248 	if (ip->i_size == length) {
249 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
250 		if (needextclean)
251 			goto extclean;
252 		return ffs_update(vp, 0);
253 	}
254 	if (fs->fs_ronly)
255 		panic("ffs_truncate: read-only filesystem");
256 	if ((ip->i_flags & SF_SNAPSHOT) != 0)
257 		ffs_snapremove(vp);
258 	vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
259 	osize = ip->i_size;
260 	/*
261 	 * Lengthen the size of the file. We must ensure that the
262 	 * last byte of the file is allocated. Since the smallest
263 	 * value of osize is 0, length will be at least 1.
264 	 */
265 	if (osize < length) {
266 		vnode_pager_setsize(vp, length);
267 		flags |= BA_CLRBUF;
268 		error = UFS_BALLOC(vp, length - 1, 1, cred, flags, &bp);
269 		if (error) {
270 			vnode_pager_setsize(vp, osize);
271 			return (error);
272 		}
273 		ip->i_size = length;
274 		DIP_SET(ip, i_size, length);
275 		if (bp->b_bufsize == fs->fs_bsize)
276 			bp->b_flags |= B_CLUSTEROK;
277 		if (flags & IO_SYNC)
278 			bwrite(bp);
279 		else
280 			bawrite(bp);
281 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
282 		return ffs_update(vp, 1);
283 	}
284 	if (DOINGSOFTDEP(vp)) {
285 		if (softdeptrunc == 0 && journaltrunc == 0) {
286 			/*
287 			 * If a file is only partially truncated, then
288 			 * we have to clean up the data structures
289 			 * describing the allocation past the truncation
290 			 * point. Finding and deallocating those structures
291 			 * is a lot of work. Since partial truncation occurs
292 			 * rarely, we solve the problem by syncing the file
293 			 * so that it will have no data structures left.
294 			 */
295 			if ((error = ffs_syncvnode(vp, MNT_WAIT)) != 0)
296 				return (error);
297 		} else {
298 			flags = IO_NORMAL | (needextclean ? IO_EXT: 0);
299 			if (journaltrunc)
300 				softdep_journal_freeblocks(ip, cred, length,
301 				    flags);
302 			else
303 				softdep_setup_freeblocks(ip, length, flags);
304 			ASSERT_VOP_LOCKED(vp, "ffs_truncate1");
305 			if (journaltrunc == 0) {
306 				ip->i_flag |= IN_CHANGE | IN_UPDATE;
307 				error = ffs_update(vp, 0);
308 			}
309 			return (error);
310 		}
311 	}
312 	/*
313 	 * Shorten the size of the file. If the file is not being
314 	 * truncated to a block boundary, the contents of the
315 	 * partial block following the end of the file must be
316 	 * zero'ed in case it ever becomes accessible again because
317 	 * of subsequent file growth. Directories however are not
318 	 * zero'ed as they should grow back initialized to empty.
319 	 */
320 	offset = blkoff(fs, length);
321 	if (offset == 0) {
322 		ip->i_size = length;
323 		DIP_SET(ip, i_size, length);
324 	} else {
325 		lbn = lblkno(fs, length);
326 		flags |= BA_CLRBUF;
327 		error = UFS_BALLOC(vp, length - 1, 1, cred, flags, &bp);
328 		if (error)
329 			return (error);
330 		/*
331 		 * When we are doing soft updates and the UFS_BALLOC
332 		 * above fills in a direct block hole with a full sized
333 		 * block that will be truncated down to a fragment below,
334 		 * we must flush out the block dependency with an FSYNC
335 		 * so that we do not get a soft updates inconsistency
336 		 * when we create the fragment below.
337 		 */
338 		if (DOINGSOFTDEP(vp) && lbn < NDADDR &&
339 		    fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize &&
340 		    (error = ffs_syncvnode(vp, MNT_WAIT)) != 0)
341 			return (error);
342 		ip->i_size = length;
343 		DIP_SET(ip, i_size, length);
344 		size = blksize(fs, ip, lbn);
345 		if (vp->v_type != VDIR)
346 			bzero((char *)bp->b_data + offset,
347 			    (u_int)(size - offset));
348 		/* Kirk's code has reallocbuf(bp, size, 1) here */
349 		allocbuf(bp, size);
350 		if (bp->b_bufsize == fs->fs_bsize)
351 			bp->b_flags |= B_CLUSTEROK;
352 		if (flags & IO_SYNC)
353 			bwrite(bp);
354 		else
355 			bawrite(bp);
356 	}
357 	/*
358 	 * Calculate index into inode's block list of
359 	 * last direct and indirect blocks (if any)
360 	 * which we want to keep.  Lastblock is -1 when
361 	 * the file is truncated to 0.
362 	 */
363 	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
364 	lastiblock[SINGLE] = lastblock - NDADDR;
365 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
366 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
367 	nblocks = btodb(fs->fs_bsize);
368 	/*
369 	 * Update file and block pointers on disk before we start freeing
370 	 * blocks.  If we crash before free'ing blocks below, the blocks
371 	 * will be returned to the free list.  lastiblock values are also
372 	 * normalized to -1 for calls to ffs_indirtrunc below.
373 	 */
374 	for (level = TRIPLE; level >= SINGLE; level--) {
375 		oldblks[NDADDR + level] = DIP(ip, i_ib[level]);
376 		if (lastiblock[level] < 0) {
377 			DIP_SET(ip, i_ib[level], 0);
378 			lastiblock[level] = -1;
379 		}
380 	}
381 	for (i = 0; i < NDADDR; i++) {
382 		oldblks[i] = DIP(ip, i_db[i]);
383 		if (i > lastblock)
384 			DIP_SET(ip, i_db[i], 0);
385 	}
386 	ip->i_flag |= IN_CHANGE | IN_UPDATE;
387 	allerror = ffs_update(vp, 1);
388 
389 	/*
390 	 * Having written the new inode to disk, save its new configuration
391 	 * and put back the old block pointers long enough to process them.
392 	 * Note that we save the new block configuration so we can check it
393 	 * when we are done.
394 	 */
395 	for (i = 0; i < NDADDR; i++) {
396 		newblks[i] = DIP(ip, i_db[i]);
397 		DIP_SET(ip, i_db[i], oldblks[i]);
398 	}
399 	for (i = 0; i < NIADDR; i++) {
400 		newblks[NDADDR + i] = DIP(ip, i_ib[i]);
401 		DIP_SET(ip, i_ib[i], oldblks[NDADDR + i]);
402 	}
403 	ip->i_size = osize;
404 	DIP_SET(ip, i_size, osize);
405 
406 	error = vtruncbuf(vp, cred, td, length, fs->fs_bsize);
407 	if (error && (allerror == 0))
408 		allerror = error;
409 
410 	/*
411 	 * Indirect blocks first.
412 	 */
413 	indir_lbn[SINGLE] = -NDADDR;
414 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
415 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
416 	for (level = TRIPLE; level >= SINGLE; level--) {
417 		bn = DIP(ip, i_ib[level]);
418 		if (bn != 0) {
419 			error = ffs_indirtrunc(ip, indir_lbn[level],
420 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
421 			if (error)
422 				allerror = error;
423 			blocksreleased += count;
424 			if (lastiblock[level] < 0) {
425 				DIP_SET(ip, i_ib[level], 0);
426 				ffs_blkfree(ump, fs, ip->i_devvp, bn,
427 				    fs->fs_bsize, ip->i_number,
428 				    vp->v_type, NULL);
429 				blocksreleased += nblocks;
430 			}
431 		}
432 		if (lastiblock[level] >= 0)
433 			goto done;
434 	}
435 
436 	/*
437 	 * All whole direct blocks or frags.
438 	 */
439 	for (i = NDADDR - 1; i > lastblock; i--) {
440 		long bsize;
441 
442 		bn = DIP(ip, i_db[i]);
443 		if (bn == 0)
444 			continue;
445 		DIP_SET(ip, i_db[i], 0);
446 		bsize = blksize(fs, ip, i);
447 		ffs_blkfree(ump, fs, ip->i_devvp, bn, bsize, ip->i_number,
448 		    vp->v_type, NULL);
449 		blocksreleased += btodb(bsize);
450 	}
451 	if (lastblock < 0)
452 		goto done;
453 
454 	/*
455 	 * Finally, look for a change in size of the
456 	 * last direct block; release any frags.
457 	 */
458 	bn = DIP(ip, i_db[lastblock]);
459 	if (bn != 0) {
460 		long oldspace, newspace;
461 
462 		/*
463 		 * Calculate amount of space we're giving
464 		 * back as old block size minus new block size.
465 		 */
466 		oldspace = blksize(fs, ip, lastblock);
467 		ip->i_size = length;
468 		DIP_SET(ip, i_size, length);
469 		newspace = blksize(fs, ip, lastblock);
470 		if (newspace == 0)
471 			panic("ffs_truncate: newspace");
472 		if (oldspace - newspace > 0) {
473 			/*
474 			 * Block number of space to be free'd is
475 			 * the old block # plus the number of frags
476 			 * required for the storage we're keeping.
477 			 */
478 			bn += numfrags(fs, newspace);
479 			ffs_blkfree(ump, fs, ip->i_devvp, bn,
480 			   oldspace - newspace, ip->i_number, vp->v_type, NULL);
481 			blocksreleased += btodb(oldspace - newspace);
482 		}
483 	}
484 done:
485 #ifdef INVARIANTS
486 	for (level = SINGLE; level <= TRIPLE; level++)
487 		if (newblks[NDADDR + level] != DIP(ip, i_ib[level]))
488 			panic("ffs_truncate1");
489 	for (i = 0; i < NDADDR; i++)
490 		if (newblks[i] != DIP(ip, i_db[i]))
491 			panic("ffs_truncate2");
492 	BO_LOCK(bo);
493 	if (length == 0 &&
494 	    (fs->fs_magic != FS_UFS2_MAGIC || ip->i_din2->di_extsize == 0) &&
495 	    (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
496 		panic("ffs_truncate3");
497 	BO_UNLOCK(bo);
498 #endif /* INVARIANTS */
499 	/*
500 	 * Put back the real size.
501 	 */
502 	ip->i_size = length;
503 	DIP_SET(ip, i_size, length);
504 	DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - blocksreleased);
505 
506 	if (DIP(ip, i_blocks) < 0)			/* sanity */
507 		DIP_SET(ip, i_blocks, 0);
508 	ip->i_flag |= IN_CHANGE;
509 #ifdef QUOTA
510 	(void) chkdq(ip, -blocksreleased, NOCRED, 0);
511 #endif
512 	return (allerror);
513 
514 extclean:
515 	if (journaltrunc)
516 		softdep_journal_freeblocks(ip, cred, length, IO_EXT);
517 	else
518 		softdep_setup_freeblocks(ip, length, IO_EXT);
519 	return ffs_update(vp, MNT_WAIT);
520 }
521 
522 /*
523  * Release blocks associated with the inode ip and stored in the indirect
524  * block bn.  Blocks are free'd in LIFO order up to (but not including)
525  * lastbn.  If level is greater than SINGLE, the block is an indirect block
526  * and recursive calls to indirtrunc must be used to cleanse other indirect
527  * blocks.
528  */
529 static int
530 ffs_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
531 	struct inode *ip;
532 	ufs2_daddr_t lbn, lastbn;
533 	ufs2_daddr_t dbn;
534 	int level;
535 	ufs2_daddr_t *countp;
536 {
537 	struct buf *bp;
538 	struct fs *fs = ip->i_fs;
539 	struct vnode *vp;
540 	caddr_t copy = NULL;
541 	int i, nblocks, error = 0, allerror = 0;
542 	ufs2_daddr_t nb, nlbn, last;
543 	ufs2_daddr_t blkcount, factor, blocksreleased = 0;
544 	ufs1_daddr_t *bap1 = NULL;
545 	ufs2_daddr_t *bap2 = NULL;
546 #	define BAP(ip, i) (((ip)->i_ump->um_fstype == UFS1) ? bap1[i] : bap2[i])
547 
548 	/*
549 	 * Calculate index in current block of last
550 	 * block to be kept.  -1 indicates the entire
551 	 * block so we need not calculate the index.
552 	 */
553 	factor = lbn_offset(fs, level);
554 	last = lastbn;
555 	if (lastbn > 0)
556 		last /= factor;
557 	nblocks = btodb(fs->fs_bsize);
558 	/*
559 	 * Get buffer of block pointers, zero those entries corresponding
560 	 * to blocks to be free'd, and update on disk copy first.  Since
561 	 * double(triple) indirect before single(double) indirect, calls
562 	 * to bmap on these blocks will fail.  However, we already have
563 	 * the on disk address, so we have to set the b_blkno field
564 	 * explicitly instead of letting bread do everything for us.
565 	 */
566 	vp = ITOV(ip);
567 	bp = getblk(vp, lbn, (int)fs->fs_bsize, 0, 0, 0);
568 	if ((bp->b_flags & B_CACHE) == 0) {
569 		curthread->td_ru.ru_inblock++;	/* pay for read */
570 		bp->b_iocmd = BIO_READ;
571 		bp->b_flags &= ~B_INVAL;
572 		bp->b_ioflags &= ~BIO_ERROR;
573 		if (bp->b_bcount > bp->b_bufsize)
574 			panic("ffs_indirtrunc: bad buffer size");
575 		bp->b_blkno = dbn;
576 		vfs_busy_pages(bp, 0);
577 		bp->b_iooffset = dbtob(bp->b_blkno);
578 		bstrategy(bp);
579 		error = bufwait(bp);
580 	}
581 	if (error) {
582 		brelse(bp);
583 		*countp = 0;
584 		return (error);
585 	}
586 
587 	if (ip->i_ump->um_fstype == UFS1)
588 		bap1 = (ufs1_daddr_t *)bp->b_data;
589 	else
590 		bap2 = (ufs2_daddr_t *)bp->b_data;
591 	if (lastbn != -1) {
592 		copy = malloc(fs->fs_bsize, M_TEMP, M_WAITOK);
593 		bcopy((caddr_t)bp->b_data, copy, (u_int)fs->fs_bsize);
594 		for (i = last + 1; i < NINDIR(fs); i++)
595 			if (ip->i_ump->um_fstype == UFS1)
596 				bap1[i] = 0;
597 			else
598 				bap2[i] = 0;
599 		if (DOINGASYNC(vp)) {
600 			bawrite(bp);
601 		} else {
602 			error = bwrite(bp);
603 			if (error)
604 				allerror = error;
605 		}
606 		if (ip->i_ump->um_fstype == UFS1)
607 			bap1 = (ufs1_daddr_t *)copy;
608 		else
609 			bap2 = (ufs2_daddr_t *)copy;
610 	}
611 
612 	/*
613 	 * Recursively free totally unused blocks.
614 	 */
615 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
616 	    i--, nlbn += factor) {
617 		nb = BAP(ip, i);
618 		if (nb == 0)
619 			continue;
620 		if (level > SINGLE) {
621 			if ((error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
622 			    (ufs2_daddr_t)-1, level - 1, &blkcount)) != 0)
623 				allerror = error;
624 			blocksreleased += blkcount;
625 		}
626 		ffs_blkfree(ip->i_ump, fs, ip->i_devvp, nb, fs->fs_bsize,
627 		    ip->i_number, vp->v_type, NULL);
628 		blocksreleased += nblocks;
629 	}
630 
631 	/*
632 	 * Recursively free last partial block.
633 	 */
634 	if (level > SINGLE && lastbn >= 0) {
635 		last = lastbn % factor;
636 		nb = BAP(ip, i);
637 		if (nb != 0) {
638 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
639 			    last, level - 1, &blkcount);
640 			if (error)
641 				allerror = error;
642 			blocksreleased += blkcount;
643 		}
644 	}
645 	if (copy != NULL) {
646 		free(copy, M_TEMP);
647 	} else {
648 		bp->b_flags |= B_INVAL | B_NOCACHE;
649 		brelse(bp);
650 	}
651 
652 	*countp = blocksreleased;
653 	return (allerror);
654 }
655 
656 int
657 ffs_rdonly(struct inode *ip)
658 {
659 
660 	return (ip->i_ump->um_fs->fs_ronly != 0);
661 }
662 
663