xref: /freebsd/sys/fs/ext2fs/ext2_inode.c (revision d6b92ffa)
1 /*-
2  *  modified for Lites 1.1
3  *
4  *  Aug 1995, Godmar Back (gback@cs.utah.edu)
5  *  University of Utah, Department of Computer Science
6  */
7 /*-
8  * Copyright (c) 1982, 1986, 1989, 1993
9  *	The Regents of the University of California.  All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)ffs_inode.c	8.5 (Berkeley) 12/30/93
36  * $FreeBSD$
37  */
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/mount.h>
42 #include <sys/bio.h>
43 #include <sys/buf.h>
44 #include <sys/vnode.h>
45 #include <sys/malloc.h>
46 #include <sys/rwlock.h>
47 
48 #include <vm/vm.h>
49 #include <vm/vm_extern.h>
50 
51 #include <fs/ext2fs/inode.h>
52 #include <fs/ext2fs/ext2_mount.h>
53 #include <fs/ext2fs/ext2fs.h>
54 #include <fs/ext2fs/fs.h>
55 #include <fs/ext2fs/ext2_extern.h>
56 #include <fs/ext2fs/ext2_extattr.h>
57 
58 static int ext2_indirtrunc(struct inode *, daddr_t, daddr_t,
59 	    daddr_t, int, e4fs_daddr_t *);
60 
61 /*
62  * Update the access, modified, and inode change times as specified by the
63  * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
64  * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
65  * the timestamp update).  The IN_LAZYMOD flag is set to force a write
66  * later if not now.  If we write now, then clear both IN_MODIFIED and
67  * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
68  * set, then wait for the write to complete.
69  */
70 int
71 ext2_update(struct vnode *vp, int waitfor)
72 {
73 	struct m_ext2fs *fs;
74 	struct buf *bp;
75 	struct inode *ip;
76 	int error;
77 
78 	ASSERT_VOP_ELOCKED(vp, "ext2_update");
79 	ext2_itimes(vp);
80 	ip = VTOI(vp);
81 	if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
82 		return (0);
83 	ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED);
84 	fs = ip->i_e2fs;
85 	if (fs->e2fs_ronly)
86 		return (0);
87 	if ((error = bread(ip->i_devvp,
88 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
89 	    (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
90 		brelse(bp);
91 		return (error);
92 	}
93 	ext2_i2ei(ip, (struct ext2fs_dinode *)((char *)bp->b_data +
94 	    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number)));
95 	if (waitfor && !DOINGASYNC(vp))
96 		return (bwrite(bp));
97 	else {
98 		bdwrite(bp);
99 		return (0);
100 	}
101 }
102 
103 #define	SINGLE	0	/* index of single indirect block */
104 #define	DOUBLE	1	/* index of double indirect block */
105 #define	TRIPLE	2	/* index of triple indirect block */
106 /*
107  * Truncate the inode oip to at most length size, freeing the
108  * disk blocks.
109  */
110 int
111 ext2_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred,
112     struct thread *td)
113 {
114 	struct vnode *ovp = vp;
115 	int32_t lastblock;
116 	struct inode *oip;
117 	int32_t bn, lbn, lastiblock[EXT2_NIADDR], indir_lbn[EXT2_NIADDR];
118 	uint32_t oldblks[EXT2_NDADDR + EXT2_NIADDR];
119 	uint32_t newblks[EXT2_NDADDR + EXT2_NIADDR];
120 	struct m_ext2fs *fs;
121 	struct buf *bp;
122 	int offset, size, level;
123 	e4fs_daddr_t count, nblocks, blocksreleased = 0;
124 	int error, i, allerror;
125 	off_t osize;
126 #ifdef INVARIANTS
127 	struct bufobj *bo;
128 #endif
129 
130 	oip = VTOI(ovp);
131 #ifdef INVARIANTS
132 	bo = &ovp->v_bufobj;
133 #endif
134 
135 	ASSERT_VOP_LOCKED(vp, "ext2_truncate");
136 
137 	if (length < 0)
138 		return (EINVAL);
139 
140 	if (ovp->v_type == VLNK &&
141 	    oip->i_size < ovp->v_mount->mnt_maxsymlinklen) {
142 #ifdef INVARIANTS
143 		if (length != 0)
144 			panic("ext2_truncate: partial truncate of symlink");
145 #endif
146 		bzero((char *)&oip->i_shortlink, (u_int)oip->i_size);
147 		oip->i_size = 0;
148 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
149 		return (ext2_update(ovp, 1));
150 	}
151 	if (oip->i_size == length) {
152 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
153 		return (ext2_update(ovp, 0));
154 	}
155 	fs = oip->i_e2fs;
156 	osize = oip->i_size;
157 	/*
158 	 * Lengthen the size of the file. We must ensure that the
159 	 * last byte of the file is allocated. Since the smallest
160 	 * value of osize is 0, length will be at least 1.
161 	 */
162 	if (osize < length) {
163 		if (length > oip->i_e2fs->e2fs_maxfilesize)
164 			return (EFBIG);
165 		vnode_pager_setsize(ovp, length);
166 		offset = blkoff(fs, length - 1);
167 		lbn = lblkno(fs, length - 1);
168 		flags |= BA_CLRBUF;
169 		error = ext2_balloc(oip, lbn, offset + 1, cred, &bp, flags);
170 		if (error) {
171 			vnode_pager_setsize(vp, osize);
172 			return (error);
173 		}
174 		oip->i_size = length;
175 		if (bp->b_bufsize == fs->e2fs_bsize)
176 			bp->b_flags |= B_CLUSTEROK;
177 		if (flags & IO_SYNC)
178 			bwrite(bp);
179 		else if (DOINGASYNC(ovp))
180 			bdwrite(bp);
181 		else
182 			bawrite(bp);
183 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
184 		return (ext2_update(ovp, !DOINGASYNC(ovp)));
185 	}
186 	/*
187 	 * Shorten the size of the file. If the file is not being
188 	 * truncated to a block boundary, the contents of the
189 	 * partial block following the end of the file must be
190 	 * zero'ed in case it ever become accessible again because
191 	 * of subsequent file growth.
192 	 */
193 	/* I don't understand the comment above */
194 	offset = blkoff(fs, length);
195 	if (offset == 0) {
196 		oip->i_size = length;
197 	} else {
198 		lbn = lblkno(fs, length);
199 		flags |= BA_CLRBUF;
200 		error = ext2_balloc(oip, lbn, offset, cred, &bp, flags);
201 		if (error)
202 			return (error);
203 		oip->i_size = length;
204 		size = blksize(fs, oip, lbn);
205 		bzero((char *)bp->b_data + offset, (u_int)(size - offset));
206 		allocbuf(bp, size);
207 		if (bp->b_bufsize == fs->e2fs_bsize)
208 			bp->b_flags |= B_CLUSTEROK;
209 		if (flags & IO_SYNC)
210 			bwrite(bp);
211 		else if (DOINGASYNC(ovp))
212 			bdwrite(bp);
213 		else
214 			bawrite(bp);
215 	}
216 	/*
217 	 * Calculate index into inode's block list of
218 	 * last direct and indirect blocks (if any)
219 	 * which we want to keep.  Lastblock is -1 when
220 	 * the file is truncated to 0.
221 	 */
222 	lastblock = lblkno(fs, length + fs->e2fs_bsize - 1) - 1;
223 	lastiblock[SINGLE] = lastblock - EXT2_NDADDR;
224 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
225 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
226 	nblocks = btodb(fs->e2fs_bsize);
227 	/*
228 	 * Update file and block pointers on disk before we start freeing
229 	 * blocks.  If we crash before free'ing blocks below, the blocks
230 	 * will be returned to the free list.  lastiblock values are also
231 	 * normalized to -1 for calls to ext2_indirtrunc below.
232 	 */
233 	for (level = TRIPLE; level >= SINGLE; level--) {
234 		oldblks[EXT2_NDADDR + level] = oip->i_ib[level];
235 		if (lastiblock[level] < 0) {
236 			oip->i_ib[level] = 0;
237 			lastiblock[level] = -1;
238 		}
239 	}
240 	for (i = 0; i < EXT2_NDADDR; i++) {
241 		oldblks[i] = oip->i_db[i];
242 		if (i > lastblock)
243 			oip->i_db[i] = 0;
244 	}
245 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
246 	allerror = ext2_update(ovp, !DOINGASYNC(ovp));
247 
248 	/*
249 	 * Having written the new inode to disk, save its new configuration
250 	 * and put back the old block pointers long enough to process them.
251 	 * Note that we save the new block configuration so we can check it
252 	 * when we are done.
253 	 */
254 	for (i = 0; i < EXT2_NDADDR; i++) {
255 		newblks[i] = oip->i_db[i];
256 		oip->i_db[i] = oldblks[i];
257 	}
258 	for (i = 0; i < EXT2_NIADDR; i++) {
259 		newblks[EXT2_NDADDR + i] = oip->i_ib[i];
260 		oip->i_ib[i] = oldblks[EXT2_NDADDR + i];
261 	}
262 	oip->i_size = osize;
263 	error = vtruncbuf(ovp, cred, length, (int)fs->e2fs_bsize);
264 	if (error && (allerror == 0))
265 		allerror = error;
266 	vnode_pager_setsize(ovp, length);
267 
268 	/*
269 	 * Indirect blocks first.
270 	 */
271 	indir_lbn[SINGLE] = -EXT2_NDADDR;
272 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
273 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
274 	for (level = TRIPLE; level >= SINGLE; level--) {
275 		bn = oip->i_ib[level];
276 		if (bn != 0) {
277 			error = ext2_indirtrunc(oip, indir_lbn[level],
278 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
279 			if (error)
280 				allerror = error;
281 			blocksreleased += count;
282 			if (lastiblock[level] < 0) {
283 				oip->i_ib[level] = 0;
284 				ext2_blkfree(oip, bn, fs->e2fs_fsize);
285 				blocksreleased += nblocks;
286 			}
287 		}
288 		if (lastiblock[level] >= 0)
289 			goto done;
290 	}
291 
292 	/*
293 	 * All whole direct blocks or frags.
294 	 */
295 	for (i = EXT2_NDADDR - 1; i > lastblock; i--) {
296 		long bsize;
297 
298 		bn = oip->i_db[i];
299 		if (bn == 0)
300 			continue;
301 		oip->i_db[i] = 0;
302 		bsize = blksize(fs, oip, i);
303 		ext2_blkfree(oip, bn, bsize);
304 		blocksreleased += btodb(bsize);
305 	}
306 	if (lastblock < 0)
307 		goto done;
308 
309 	/*
310 	 * Finally, look for a change in size of the
311 	 * last direct block; release any frags.
312 	 */
313 	bn = oip->i_db[lastblock];
314 	if (bn != 0) {
315 		long oldspace, newspace;
316 
317 		/*
318 		 * Calculate amount of space we're giving
319 		 * back as old block size minus new block size.
320 		 */
321 		oldspace = blksize(fs, oip, lastblock);
322 		oip->i_size = length;
323 		newspace = blksize(fs, oip, lastblock);
324 		if (newspace == 0)
325 			panic("ext2_truncate: newspace");
326 		if (oldspace - newspace > 0) {
327 			/*
328 			 * Block number of space to be free'd is
329 			 * the old block # plus the number of frags
330 			 * required for the storage we're keeping.
331 			 */
332 			bn += numfrags(fs, newspace);
333 			ext2_blkfree(oip, bn, oldspace - newspace);
334 			blocksreleased += btodb(oldspace - newspace);
335 		}
336 	}
337 done:
338 #ifdef INVARIANTS
339 	for (level = SINGLE; level <= TRIPLE; level++)
340 		if (newblks[EXT2_NDADDR + level] != oip->i_ib[level])
341 			panic("itrunc1");
342 	for (i = 0; i < EXT2_NDADDR; i++)
343 		if (newblks[i] != oip->i_db[i])
344 			panic("itrunc2");
345 	BO_LOCK(bo);
346 	if (length == 0 && (bo->bo_dirty.bv_cnt != 0 ||
347 	    bo->bo_clean.bv_cnt != 0))
348 		panic("itrunc3");
349 	BO_UNLOCK(bo);
350 #endif	/* INVARIANTS */
351 	/*
352 	 * Put back the real size.
353 	 */
354 	oip->i_size = length;
355 	if (oip->i_blocks >= blocksreleased)
356 		oip->i_blocks -= blocksreleased;
357 	else				/* sanity */
358 		oip->i_blocks = 0;
359 	oip->i_flag |= IN_CHANGE;
360 	vnode_pager_setsize(ovp, length);
361 	return (allerror);
362 }
363 
364 /*
365  * Release blocks associated with the inode ip and stored in the indirect
366  * block bn.  Blocks are free'd in LIFO order up to (but not including)
367  * lastbn.  If level is greater than SINGLE, the block is an indirect block
368  * and recursive calls to indirtrunc must be used to cleanse other indirect
369  * blocks.
370  *
371  * NB: triple indirect blocks are untested.
372  */
373 
374 static int
375 ext2_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn,
376     daddr_t lastbn, int level, e4fs_daddr_t *countp)
377 {
378 	struct buf *bp;
379 	struct m_ext2fs *fs = ip->i_e2fs;
380 	struct vnode *vp;
381 	e2fs_daddr_t *bap, *copy;
382 	int i, nblocks, error = 0, allerror = 0;
383 	e2fs_lbn_t nb, nlbn, last;
384 	e4fs_daddr_t blkcount, factor, blocksreleased = 0;
385 
386 	/*
387 	 * Calculate index in current block of last
388 	 * block to be kept.  -1 indicates the entire
389 	 * block so we need not calculate the index.
390 	 */
391 	factor = 1;
392 	for (i = SINGLE; i < level; i++)
393 		factor *= NINDIR(fs);
394 	last = lastbn;
395 	if (lastbn > 0)
396 		last /= factor;
397 	nblocks = btodb(fs->e2fs_bsize);
398 	/*
399 	 * Get buffer of block pointers, zero those entries corresponding
400 	 * to blocks to be free'd, and update on disk copy first.  Since
401 	 * double(triple) indirect before single(double) indirect, calls
402 	 * to bmap on these blocks will fail.  However, we already have
403 	 * the on disk address, so we have to set the b_blkno field
404 	 * explicitly instead of letting bread do everything for us.
405 	 */
406 	vp = ITOV(ip);
407 	bp = getblk(vp, lbn, (int)fs->e2fs_bsize, 0, 0, 0);
408 	if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) {
409 		bp->b_iocmd = BIO_READ;
410 		if (bp->b_bcount > bp->b_bufsize)
411 			panic("ext2_indirtrunc: bad buffer size");
412 		bp->b_blkno = dbn;
413 		vfs_busy_pages(bp, 0);
414 		bp->b_iooffset = dbtob(bp->b_blkno);
415 		bstrategy(bp);
416 		error = bufwait(bp);
417 	}
418 	if (error) {
419 		brelse(bp);
420 		*countp = 0;
421 		return (error);
422 	}
423 	bap = (e2fs_daddr_t *)bp->b_data;
424 	copy = malloc(fs->e2fs_bsize, M_TEMP, M_WAITOK);
425 	bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->e2fs_bsize);
426 	bzero((caddr_t)&bap[last + 1],
427 	    (NINDIR(fs) - (last + 1)) * sizeof(e2fs_daddr_t));
428 	if (last == -1)
429 		bp->b_flags |= B_INVAL;
430 	if (DOINGASYNC(vp)) {
431 		bdwrite(bp);
432 	} else {
433 		error = bwrite(bp);
434 		if (error)
435 			allerror = error;
436 	}
437 	bap = copy;
438 
439 	/*
440 	 * Recursively free totally unused blocks.
441 	 */
442 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
443 	    i--, nlbn += factor) {
444 		nb = bap[i];
445 		if (nb == 0)
446 			continue;
447 		if (level > SINGLE) {
448 			if ((error = ext2_indirtrunc(ip, nlbn,
449 			    fsbtodb(fs, nb), (int32_t)-1, level - 1, &blkcount)) != 0)
450 				allerror = error;
451 			blocksreleased += blkcount;
452 		}
453 		ext2_blkfree(ip, nb, fs->e2fs_bsize);
454 		blocksreleased += nblocks;
455 	}
456 
457 	/*
458 	 * Recursively free last partial block.
459 	 */
460 	if (level > SINGLE && lastbn >= 0) {
461 		last = lastbn % factor;
462 		nb = bap[i];
463 		if (nb != 0) {
464 			if ((error = ext2_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
465 			    last, level - 1, &blkcount)) != 0)
466 				allerror = error;
467 			blocksreleased += blkcount;
468 		}
469 	}
470 	free(copy, M_TEMP);
471 	*countp = blocksreleased;
472 	return (allerror);
473 }
474 
475 /*
476  *	discard preallocated blocks
477  */
478 int
479 ext2_inactive(struct vop_inactive_args *ap)
480 {
481 	struct vnode *vp = ap->a_vp;
482 	struct inode *ip = VTOI(vp);
483 	struct thread *td = ap->a_td;
484 	int mode, error = 0;
485 
486 	/*
487 	 * Ignore inodes related to stale file handles.
488 	 */
489 	if (ip->i_mode == 0)
490 		goto out;
491 	if (ip->i_nlink <= 0) {
492 		ext2_extattr_free(ip);
493 		error = ext2_truncate(vp, (off_t)0, 0, NOCRED, td);
494 		ip->i_rdev = 0;
495 		mode = ip->i_mode;
496 		ip->i_mode = 0;
497 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
498 		ext2_vfree(vp, ip->i_number, mode);
499 	}
500 	if (ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE))
501 		ext2_update(vp, 0);
502 out:
503 	/*
504 	 * If we are done with the inode, reclaim it
505 	 * so that it can be reused immediately.
506 	 */
507 	if (ip->i_mode == 0)
508 		vrecycle(vp);
509 	return (error);
510 }
511 
512 /*
513  * Reclaim an inode so that it can be used for other purposes.
514  */
515 int
516 ext2_reclaim(struct vop_reclaim_args *ap)
517 {
518 	struct inode *ip;
519 	struct vnode *vp = ap->a_vp;
520 
521 	ip = VTOI(vp);
522 	if (ip->i_flag & IN_LAZYMOD) {
523 		ip->i_flag |= IN_MODIFIED;
524 		ext2_update(vp, 0);
525 	}
526 	vfs_hash_remove(vp);
527 	free(vp->v_data, M_EXT2NODE);
528 	vp->v_data = 0;
529 	vnode_destroy_vobject(vp);
530 	return (0);
531 }
532