xref: /freebsd/sys/fs/ext2fs/ext2_inode.c (revision 2e5b60079b7d8c3ca68f1390cd90f305e651f8d3)
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  * 4. 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 
57 static int ext2_indirtrunc(struct inode *, daddr_t, daddr_t,
58 	    daddr_t, int, e4fs_daddr_t *);
59 
60 /*
61  * Update the access, modified, and inode change times as specified by the
62  * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
63  * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
64  * the timestamp update).  The IN_LAZYMOD flag is set to force a write
65  * later if not now.  If we write now, then clear both IN_MODIFIED and
66  * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
67  * set, then wait for the write to complete.
68  */
69 int
70 ext2_update(struct vnode *vp, int waitfor)
71 {
72 	struct m_ext2fs *fs;
73 	struct buf *bp;
74 	struct inode *ip;
75 	int error;
76 
77 	ASSERT_VOP_ELOCKED(vp, "ext2_update");
78 	ext2_itimes(vp);
79 	ip = VTOI(vp);
80 	if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
81 		return (0);
82 	ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED);
83 	fs = ip->i_e2fs;
84 	if(fs->e2fs_ronly)
85 		return (0);
86 	if ((error = bread(ip->i_devvp,
87 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
88 		(int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
89 		brelse(bp);
90 		return (error);
91 	}
92 	ext2_i2ei(ip, (struct ext2fs_dinode *)((char *)bp->b_data +
93 	    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number)));
94 	if (waitfor && !DOINGASYNC(vp))
95 		return (bwrite(bp));
96 	else {
97 		bdwrite(bp);
98 		return (0);
99 	}
100 }
101 
102 #define	SINGLE	0	/* index of single indirect block */
103 #define	DOUBLE	1	/* index of double indirect block */
104 #define	TRIPLE	2	/* index of triple indirect block */
105 /*
106  * Truncate the inode oip to at most length size, freeing the
107  * disk blocks.
108  */
109 int
110 ext2_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred,
111     struct thread *td)
112 {
113 	struct vnode *ovp = vp;
114 	int32_t lastblock;
115 	struct inode *oip;
116 	int32_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
117 	uint32_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
118 	struct m_ext2fs *fs;
119 	struct buf *bp;
120 	int offset, size, level;
121 	e4fs_daddr_t count, nblocks, blocksreleased = 0;
122 	int error, i, allerror;
123 	off_t osize;
124 
125 	oip = VTOI(ovp);
126 
127 	ASSERT_VOP_LOCKED(vp, "ext2_truncate");
128 
129 	if (length < 0)
130 	    return (EINVAL);
131 
132 	if (ovp->v_type == VLNK &&
133 	    oip->i_size < ovp->v_mount->mnt_maxsymlinklen) {
134 #ifdef INVARIANTS
135 		if (length != 0)
136 			panic("ext2_truncate: partial truncate of symlink");
137 #endif
138 		bzero((char *)&oip->i_shortlink, (u_int)oip->i_size);
139 		oip->i_size = 0;
140 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
141 		return (ext2_update(ovp, 1));
142 	}
143 	if (oip->i_size == length) {
144 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
145 		return (ext2_update(ovp, 0));
146 	}
147 	fs = oip->i_e2fs;
148 	osize = oip->i_size;
149 	/*
150 	 * Lengthen the size of the file. We must ensure that the
151 	 * last byte of the file is allocated. Since the smallest
152 	 * value of osize is 0, length will be at least 1.
153 	 */
154 	if (osize < length) {
155 		if (length > oip->i_e2fs->e2fs_maxfilesize)
156 			return (EFBIG);
157 		vnode_pager_setsize(ovp, length);
158 		offset = blkoff(fs, length - 1);
159 		lbn = lblkno(fs, length - 1);
160 		flags |= BA_CLRBUF;
161 		error = ext2_balloc(oip, lbn, offset + 1, cred, &bp, flags);
162 		if (error) {
163 			vnode_pager_setsize(vp, osize);
164 			return (error);
165 		}
166 		oip->i_size = length;
167 		if (bp->b_bufsize == fs->e2fs_bsize)
168 			bp->b_flags |= B_CLUSTEROK;
169 		if (flags & IO_SYNC)
170 			bwrite(bp);
171 		else if (DOINGASYNC(ovp))
172 			bdwrite(bp);
173 		else
174 			bawrite(bp);
175 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
176 		return (ext2_update(ovp, !DOINGASYNC(ovp)));
177 	}
178 	/*
179 	 * Shorten the size of the file. If the file is not being
180 	 * truncated to a block boundry, the contents of the
181 	 * partial block following the end of the file must be
182 	 * zero'ed in case it ever become accessible again because
183 	 * of subsequent file growth.
184 	 */
185 	/* I don't understand the comment above */
186 	offset = blkoff(fs, length);
187 	if (offset == 0) {
188 		oip->i_size = length;
189 	} else {
190 		lbn = lblkno(fs, length);
191 		flags |= BA_CLRBUF;
192 		error = ext2_balloc(oip, lbn, offset, cred, &bp, flags);
193 		if (error)
194 			return (error);
195 		oip->i_size = length;
196 		size = blksize(fs, oip, lbn);
197 		bzero((char *)bp->b_data + offset, (u_int)(size - offset));
198 		allocbuf(bp, size);
199 		if (bp->b_bufsize == fs->e2fs_bsize)
200 			bp->b_flags |= B_CLUSTEROK;
201 		if (flags & IO_SYNC)
202 			bwrite(bp);
203 		else if (DOINGASYNC(ovp))
204 			bdwrite(bp);
205 		else
206 			bawrite(bp);
207 	}
208 	/*
209 	 * Calculate index into inode's block list of
210 	 * last direct and indirect blocks (if any)
211 	 * which we want to keep.  Lastblock is -1 when
212 	 * the file is truncated to 0.
213 	 */
214 	lastblock = lblkno(fs, length + fs->e2fs_bsize - 1) - 1;
215 	lastiblock[SINGLE] = lastblock - NDADDR;
216 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
217 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
218 	nblocks = btodb(fs->e2fs_bsize);
219 	/*
220 	 * Update file and block pointers on disk before we start freeing
221 	 * blocks.  If we crash before free'ing blocks below, the blocks
222 	 * will be returned to the free list.  lastiblock values are also
223 	 * normalized to -1 for calls to ext2_indirtrunc below.
224 	 */
225 	for (level = TRIPLE; level >= SINGLE; level--) {
226 		oldblks[NDADDR + level] = oip->i_ib[level];
227 		if (lastiblock[level] < 0) {
228 			oip->i_ib[level] = 0;
229 			lastiblock[level] = -1;
230 		}
231 	}
232 	for (i = 0; i < NDADDR; i++) {
233 		oldblks[i] = oip->i_db[i];
234 		if (i > lastblock)
235 			oip->i_db[i] = 0;
236 	}
237 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
238 	allerror = ext2_update(ovp, !DOINGASYNC(ovp));
239 
240 	/*
241 	 * Having written the new inode to disk, save its new configuration
242 	 * and put back the old block pointers long enough to process them.
243 	 * Note that we save the new block configuration so we can check it
244 	 * when we are done.
245 	 */
246 	for (i = 0; i < NDADDR; i++) {
247 		newblks[i] = oip->i_db[i];
248 		oip->i_db[i] = oldblks[i];
249 	}
250 	for (i = 0; i < NIADDR; i++) {
251 		newblks[NDADDR + i] = oip->i_ib[i];
252 		oip->i_ib[i] = oldblks[NDADDR + i];
253 	}
254 	oip->i_size = osize;
255 	error = vtruncbuf(ovp, cred, length, (int)fs->e2fs_bsize);
256 	if (error && (allerror == 0))
257 		allerror = error;
258 	vnode_pager_setsize(ovp, length);
259 
260 	/*
261 	 * Indirect blocks first.
262 	 */
263 	indir_lbn[SINGLE] = -NDADDR;
264 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
265 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
266 	for (level = TRIPLE; level >= SINGLE; level--) {
267 		bn = oip->i_ib[level];
268 		if (bn != 0) {
269 			error = ext2_indirtrunc(oip, indir_lbn[level],
270 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
271 			if (error)
272 				allerror = error;
273 			blocksreleased += count;
274 			if (lastiblock[level] < 0) {
275 				oip->i_ib[level] = 0;
276 				ext2_blkfree(oip, bn, fs->e2fs_fsize);
277 				blocksreleased += nblocks;
278 			}
279 		}
280 		if (lastiblock[level] >= 0)
281 			goto done;
282 	}
283 
284 	/*
285 	 * All whole direct blocks or frags.
286 	 */
287 	for (i = NDADDR - 1; i > lastblock; i--) {
288 		long bsize;
289 
290 		bn = oip->i_db[i];
291 		if (bn == 0)
292 			continue;
293 		oip->i_db[i] = 0;
294 		bsize = blksize(fs, oip, i);
295 		ext2_blkfree(oip, bn, bsize);
296 		blocksreleased += btodb(bsize);
297 	}
298 	if (lastblock < 0)
299 		goto done;
300 
301 	/*
302 	 * Finally, look for a change in size of the
303 	 * last direct block; release any frags.
304 	 */
305 	bn = oip->i_db[lastblock];
306 	if (bn != 0) {
307 		long oldspace, newspace;
308 
309 		/*
310 		 * Calculate amount of space we're giving
311 		 * back as old block size minus new block size.
312 		 */
313 		oldspace = blksize(fs, oip, lastblock);
314 		oip->i_size = length;
315 		newspace = blksize(fs, oip, lastblock);
316 		if (newspace == 0)
317 			panic("ext2_truncate: newspace");
318 		if (oldspace - newspace > 0) {
319 			/*
320 			 * Block number of space to be free'd is
321 			 * the old block # plus the number of frags
322 			 * required for the storage we're keeping.
323 			 */
324 			bn += numfrags(fs, newspace);
325 			ext2_blkfree(oip, bn, oldspace - newspace);
326 			blocksreleased += btodb(oldspace - newspace);
327 		}
328 	}
329 done:
330 #ifdef INVARIANTS
331 	for (level = SINGLE; level <= TRIPLE; level++)
332 		if (newblks[NDADDR + level] != oip->i_ib[level])
333 			panic("itrunc1");
334 	for (i = 0; i < NDADDR; i++)
335 		if (newblks[i] != oip->i_db[i])
336 			panic("itrunc2");
337 	BO_LOCK(bo);
338 	if (length == 0 && (bo->bo_dirty.bv_cnt != 0 ||
339 	    bo->bo_clean.bv_cnt != 0))
340 		panic("itrunc3");
341 	BO_UNLOCK(bo);
342 #endif /* INVARIANTS */
343 	/*
344 	 * Put back the real size.
345 	 */
346 	oip->i_size = length;
347 	if (oip->i_blocks >= blocksreleased)
348 		oip->i_blocks -= blocksreleased;
349 	else				/* sanity */
350 		oip->i_blocks = 0;
351 	oip->i_flag |= IN_CHANGE;
352 	vnode_pager_setsize(ovp, length);
353 	return (allerror);
354 }
355 
356 /*
357  * Release blocks associated with the inode ip and stored in the indirect
358  * block bn.  Blocks are free'd in LIFO order up to (but not including)
359  * lastbn.  If level is greater than SINGLE, the block is an indirect block
360  * and recursive calls to indirtrunc must be used to cleanse other indirect
361  * blocks.
362  *
363  * NB: triple indirect blocks are untested.
364  */
365 
366 static int
367 ext2_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn,
368     daddr_t lastbn, int level, e4fs_daddr_t *countp)
369 {
370 	struct buf *bp;
371 	struct m_ext2fs *fs = ip->i_e2fs;
372 	struct vnode *vp;
373 	e2fs_daddr_t *bap, *copy;
374 	int i, nblocks, error = 0, allerror = 0;
375 	e2fs_lbn_t nb, nlbn, last;
376 	e4fs_daddr_t blkcount, factor, blocksreleased = 0;
377 
378 	/*
379 	 * Calculate index in current block of last
380 	 * block to be kept.  -1 indicates the entire
381 	 * block so we need not calculate the index.
382 	 */
383 	factor = 1;
384 	for (i = SINGLE; i < level; i++)
385 		factor *= NINDIR(fs);
386 	last = lastbn;
387 	if (lastbn > 0)
388 		last /= factor;
389 	nblocks = btodb(fs->e2fs_bsize);
390 	/*
391 	 * Get buffer of block pointers, zero those entries corresponding
392 	 * to blocks to be free'd, and update on disk copy first.  Since
393 	 * double(triple) indirect before single(double) indirect, calls
394 	 * to bmap on these blocks will fail.  However, we already have
395 	 * the on disk address, so we have to set the b_blkno field
396 	 * explicitly instead of letting bread do everything for us.
397 	 */
398 	vp = ITOV(ip);
399 	bp = getblk(vp, lbn, (int)fs->e2fs_bsize, 0, 0, 0);
400 	if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) {
401 		bp->b_iocmd = BIO_READ;
402 		if (bp->b_bcount > bp->b_bufsize)
403 			panic("ext2_indirtrunc: bad buffer size");
404 		bp->b_blkno = dbn;
405 		vfs_busy_pages(bp, 0);
406 		bp->b_iooffset = dbtob(bp->b_blkno);
407 		bstrategy(bp);
408 		error = bufwait(bp);
409 	}
410 	if (error) {
411 		brelse(bp);
412 		*countp = 0;
413 		return (error);
414 	}
415 
416 	bap = (e2fs_daddr_t *)bp->b_data;
417 	copy = malloc(fs->e2fs_bsize, M_TEMP, M_WAITOK);
418 	bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->e2fs_bsize);
419 	bzero((caddr_t)&bap[last + 1],
420 	  (NINDIR(fs) - (last + 1)) * sizeof(e2fs_daddr_t));
421 	if (last == -1)
422 		bp->b_flags |= B_INVAL;
423 	if (DOINGASYNC(vp)) {
424 		bdwrite(bp);
425 	} else {
426 		error = bwrite(bp);
427 		if (error)
428 			allerror = error;
429 	}
430 	bap = copy;
431 
432 	/*
433 	 * Recursively free totally unused blocks.
434 	 */
435 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
436 	    i--, nlbn += factor) {
437 		nb = bap[i];
438 		if (nb == 0)
439 			continue;
440 		if (level > SINGLE) {
441 			if ((error = ext2_indirtrunc(ip, nlbn,
442 			    fsbtodb(fs, nb), (int32_t)-1, level - 1, &blkcount)) != 0)
443 				allerror = error;
444 			blocksreleased += blkcount;
445 		}
446 		ext2_blkfree(ip, nb, fs->e2fs_bsize);
447 		blocksreleased += nblocks;
448 	}
449 
450 	/*
451 	 * Recursively free last partial block.
452 	 */
453 	if (level > SINGLE && lastbn >= 0) {
454 		last = lastbn % factor;
455 		nb = bap[i];
456 		if (nb != 0) {
457 			if ((error = ext2_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
458 			    last, level - 1, &blkcount)) != 0)
459 				allerror = error;
460 			blocksreleased += blkcount;
461 		}
462 	}
463 	free(copy, M_TEMP);
464 	*countp = blocksreleased;
465 	return (allerror);
466 }
467 
468 /*
469  *	discard preallocated blocks
470  */
471 int
472 ext2_inactive(struct vop_inactive_args *ap)
473 {
474 	struct vnode *vp = ap->a_vp;
475 	struct inode *ip = VTOI(vp);
476 	struct thread *td = ap->a_td;
477 	int mode, error = 0;
478 
479 	/*
480 	 * Ignore inodes related to stale file handles.
481 	 */
482 	if (ip->i_mode == 0)
483 		goto out;
484 	if (ip->i_nlink <= 0) {
485 		error = ext2_truncate(vp, (off_t)0, 0, NOCRED, td);
486 		ip->i_rdev = 0;
487 		mode = ip->i_mode;
488 		ip->i_mode = 0;
489 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
490 		ext2_vfree(vp, ip->i_number, mode);
491 	}
492 	if (ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE))
493 		ext2_update(vp, 0);
494 out:
495 	/*
496 	 * If we are done with the inode, reclaim it
497 	 * so that it can be reused immediately.
498 	 */
499 	if (ip->i_mode == 0)
500 		vrecycle(vp);
501 	return (error);
502 }
503 
504 /*
505  * Reclaim an inode so that it can be used for other purposes.
506  */
507 int
508 ext2_reclaim(struct vop_reclaim_args *ap)
509 {
510 	struct inode *ip;
511 	struct vnode *vp = ap->a_vp;
512 
513 	ip = VTOI(vp);
514 	if (ip->i_flag & IN_LAZYMOD) {
515 		ip->i_flag |= IN_MODIFIED;
516 		ext2_update(vp, 0);
517 	}
518 	vfs_hash_remove(vp);
519 	free(vp->v_data, M_EXT2NODE);
520 	vp->v_data = 0;
521 	vnode_destroy_vobject(vp);
522 	return (0);
523 }
524