xref: /freebsd/sys/fs/ext2fs/ext2_inode.c (revision ab2043b81eaba0d7d7769b4a58b2b6d17bc464a3)
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 
47 #include <vm/vm.h>
48 #include <vm/vm_extern.h>
49 
50 #include <fs/ext2fs/inode.h>
51 #include <fs/ext2fs/ext2_mount.h>
52 #include <fs/ext2fs/ext2fs.h>
53 #include <fs/ext2fs/fs.h>
54 #include <fs/ext2fs/ext2_extern.h>
55 
56 static int ext2_indirtrunc(struct inode *, int32_t, int32_t, int32_t, int,
57 	    long *);
58 
59 /*
60  * Update the access, modified, and inode change times as specified by the
61  * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
62  * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
63  * the timestamp update).  The IN_LAZYMOD flag is set to force a write
64  * later if not now.  If we write now, then clear both IN_MODIFIED and
65  * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
66  * set, then wait for the write to complete.
67  */
68 int
69 ext2_update(vp, waitfor)
70 	struct vnode *vp;
71 	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(vp, length, flags, cred, td)
112 	struct vnode *vp;
113 	off_t length;
114 	int flags;
115 	struct ucred *cred;
116 	struct thread *td;
117 {
118 	struct vnode *ovp = vp;
119 	int32_t lastblock;
120 	struct inode *oip;
121 	int32_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
122 	int32_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
123 	struct bufobj *bo;
124 	struct m_ext2fs *fs;
125 	struct buf *bp;
126 	int offset, size, level;
127 	long count, nblocks, blocksreleased = 0;
128 	int error, i, allerror;
129 	off_t osize;
130 
131 	oip = VTOI(ovp);
132 	bo = &ovp->v_bufobj;
133 
134 	ASSERT_VOP_LOCKED(vp, "ext2_truncate");
135 
136 	if (length < 0)
137 	    return (EINVAL);
138 
139 	if (ovp->v_type == VLNK &&
140 	    oip->i_size < ovp->v_mount->mnt_maxsymlinklen) {
141 #ifdef DIAGNOSTIC
142 		if (length != 0)
143 			panic("ext2_truncate: partial truncate of symlink");
144 #endif
145 		bzero((char *)&oip->i_shortlink, (u_int)oip->i_size);
146 		oip->i_size = 0;
147 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
148 		return (ext2_update(ovp, 1));
149 	}
150 	if (oip->i_size == length) {
151 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
152 		return (ext2_update(ovp, 0));
153 	}
154 	fs = oip->i_e2fs;
155 	osize = oip->i_size;
156 	/*
157 	 * Lengthen the size of the file. We must ensure that the
158 	 * last byte of the file is allocated. Since the smallest
159 	 * value of osize is 0, length will be at least 1.
160 	 */
161 	if (osize < length) {
162 		if (length > oip->i_e2fs->e2fs_maxfilesize)
163 			return (EFBIG);
164 		vnode_pager_setsize(ovp, length);
165 		offset = blkoff(fs, length - 1);
166 		lbn = lblkno(fs, length - 1);
167 		flags |= BA_CLRBUF;
168 		error = ext2_balloc(oip, lbn, offset + 1, cred, &bp, flags);
169 		if (error) {
170 			vnode_pager_setsize(vp, osize);
171 			return (error);
172 		}
173 		oip->i_size = length;
174 		if (bp->b_bufsize == fs->e2fs_bsize)
175 			bp->b_flags |= B_CLUSTEROK;
176 		if (flags & IO_SYNC)
177 			bwrite(bp);
178 		else if (DOINGASYNC(ovp))
179 			bdwrite(bp);
180 		else
181 			bawrite(bp);
182 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
183 		return (ext2_update(ovp, 1));
184 	}
185 	/*
186 	 * Shorten the size of the file. If the file is not being
187 	 * truncated to a block boundry, the contents of the
188 	 * partial block following the end of the file must be
189 	 * zero'ed in case it ever become accessible again because
190 	 * of subsequent file growth.
191 	 */
192 	/* I don't understand the comment above */
193 	offset = blkoff(fs, length);
194 	if (offset == 0) {
195 		oip->i_size = length;
196 	} else {
197 		lbn = lblkno(fs, length);
198 		flags |= BA_CLRBUF;
199 		error = ext2_balloc(oip, lbn, offset, cred, &bp, flags);
200 		if (error)
201 			return (error);
202 		oip->i_size = length;
203 		size = blksize(fs, oip, lbn);
204 		bzero((char *)bp->b_data + offset, (u_int)(size - offset));
205 		allocbuf(bp, size);
206 		if (bp->b_bufsize == fs->e2fs_bsize)
207 			bp->b_flags |= B_CLUSTEROK;
208 		if (flags & IO_SYNC)
209 			bwrite(bp);
210 		else if (DOINGASYNC(ovp))
211 			bdwrite(bp);
212 		else
213 			bawrite(bp);
214 	}
215 	/*
216 	 * Calculate index into inode's block list of
217 	 * last direct and indirect blocks (if any)
218 	 * which we want to keep.  Lastblock is -1 when
219 	 * the file is truncated to 0.
220 	 */
221 	lastblock = lblkno(fs, length + fs->e2fs_bsize - 1) - 1;
222 	lastiblock[SINGLE] = lastblock - NDADDR;
223 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
224 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
225 	nblocks = btodb(fs->e2fs_bsize);
226 	/*
227 	 * Update file and block pointers on disk before we start freeing
228 	 * blocks.  If we crash before free'ing blocks below, the blocks
229 	 * will be returned to the free list.  lastiblock values are also
230 	 * normalized to -1 for calls to ext2_indirtrunc below.
231 	 */
232 	bcopy((caddr_t)&oip->i_db[0], (caddr_t)oldblks, sizeof(oldblks));
233 	for (level = TRIPLE; level >= SINGLE; level--)
234 		if (lastiblock[level] < 0) {
235 			oip->i_ib[level] = 0;
236 			lastiblock[level] = -1;
237 		}
238 	for (i = NDADDR - 1; i > lastblock; i--)
239 		oip->i_db[i] = 0;
240 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
241 	allerror = ext2_update(ovp, 1);
242 
243 	/*
244 	 * Having written the new inode to disk, save its new configuration
245 	 * and put back the old block pointers long enough to process them.
246 	 * Note that we save the new block configuration so we can check it
247 	 * when we are done.
248 	 */
249 	bcopy((caddr_t)&oip->i_db[0], (caddr_t)newblks, sizeof(newblks));
250 	bcopy((caddr_t)oldblks, (caddr_t)&oip->i_db[0], sizeof(oldblks));
251 	oip->i_size = osize;
252 	error = vtruncbuf(ovp, cred, length, (int)fs->e2fs_bsize);
253 	if (error && (allerror == 0))
254 		allerror = error;
255 	vnode_pager_setsize(ovp, length);
256 
257 	/*
258 	 * Indirect blocks first.
259 	 */
260 	indir_lbn[SINGLE] = -NDADDR;
261 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
262 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
263 	for (level = TRIPLE; level >= SINGLE; level--) {
264 		bn = oip->i_ib[level];
265 		if (bn != 0) {
266 			error = ext2_indirtrunc(oip, indir_lbn[level],
267 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
268 			if (error)
269 				allerror = error;
270 			blocksreleased += count;
271 			if (lastiblock[level] < 0) {
272 				oip->i_ib[level] = 0;
273 				ext2_blkfree(oip, bn, fs->e2fs_fsize);
274 				blocksreleased += nblocks;
275 			}
276 		}
277 		if (lastiblock[level] >= 0)
278 			goto done;
279 	}
280 
281 	/*
282 	 * All whole direct blocks or frags.
283 	 */
284 	for (i = NDADDR - 1; i > lastblock; i--) {
285 		long bsize;
286 
287 		bn = oip->i_db[i];
288 		if (bn == 0)
289 			continue;
290 		oip->i_db[i] = 0;
291 		bsize = blksize(fs, oip, i);
292 		ext2_blkfree(oip, bn, bsize);
293 		blocksreleased += btodb(bsize);
294 	}
295 	if (lastblock < 0)
296 		goto done;
297 
298 	/*
299 	 * Finally, look for a change in size of the
300 	 * last direct block; release any frags.
301 	 */
302 	bn = oip->i_db[lastblock];
303 	if (bn != 0) {
304 		long oldspace, newspace;
305 
306 		/*
307 		 * Calculate amount of space we're giving
308 		 * back as old block size minus new block size.
309 		 */
310 		oldspace = blksize(fs, oip, lastblock);
311 		oip->i_size = length;
312 		newspace = blksize(fs, oip, lastblock);
313 		if (newspace == 0)
314 			panic("itrunc: newspace");
315 		if (oldspace - newspace > 0) {
316 			/*
317 			 * Block number of space to be free'd is
318 			 * the old block # plus the number of frags
319 			 * required for the storage we're keeping.
320 			 */
321 			bn += numfrags(fs, newspace);
322 			ext2_blkfree(oip, bn, oldspace - newspace);
323 			blocksreleased += btodb(oldspace - newspace);
324 		}
325 	}
326 done:
327 #ifdef DIAGNOSTIC
328 	for (level = SINGLE; level <= TRIPLE; level++)
329 		if (newblks[NDADDR + level] != oip->i_ib[level])
330 			panic("itrunc1");
331 	for (i = 0; i < NDADDR; i++)
332 		if (newblks[i] != oip->i_db[i])
333 			panic("itrunc2");
334 	BO_LOCK(bo);
335 	if (length == 0 && (bo->bo_dirty.bv_cnt != 0 ||
336 	    bo->bo_clean.bv_cnt != 0))
337 		panic("itrunc3");
338 	BO_UNLOCK(bo);
339 #endif /* DIAGNOSTIC */
340 	/*
341 	 * Put back the real size.
342 	 */
343 	oip->i_size = length;
344 	oip->i_blocks -= blocksreleased;
345 	if (oip->i_blocks < 0)			/* sanity */
346 		oip->i_blocks = 0;
347 	oip->i_flag |= IN_CHANGE;
348 	vnode_pager_setsize(ovp, length);
349 	return (allerror);
350 }
351 
352 /*
353  * Release blocks associated with the inode ip and stored in the indirect
354  * block bn.  Blocks are free'd in LIFO order up to (but not including)
355  * lastbn.  If level is greater than SINGLE, the block is an indirect block
356  * and recursive calls to indirtrunc must be used to cleanse other indirect
357  * blocks.
358  *
359  * NB: triple indirect blocks are untested.
360  */
361 
362 static int
363 ext2_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
364 	struct inode *ip;
365 	int32_t lbn, lastbn;
366 	int32_t dbn;
367 	int level;
368 	long *countp;
369 {
370 	struct buf *bp;
371 	struct m_ext2fs *fs = ip->i_e2fs;
372 	struct vnode *vp;
373 	int32_t *bap, *copy, nb, nlbn, last;
374 	long blkcount, factor;
375 	int i, nblocks, blocksreleased = 0;
376 	int error = 0, allerror = 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 = (int32_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 	  (u_int)(NINDIR(fs) - (last + 1)) * sizeof(int32_t));
421 	if (last == -1)
422 		bp->b_flags |= B_INVAL;
423 	error = bwrite(bp);
424 	if (error)
425 		allerror = error;
426 	bap = copy;
427 
428 	/*
429 	 * Recursively free totally unused blocks.
430 	 */
431 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
432 	    i--, nlbn += factor) {
433 		nb = bap[i];
434 		if (nb == 0)
435 			continue;
436 		if (level > SINGLE) {
437 			if ((error = ext2_indirtrunc(ip, nlbn,
438 			    fsbtodb(fs, nb), (int32_t)-1, level - 1, &blkcount)) != 0)
439 				allerror = error;
440 			blocksreleased += blkcount;
441 		}
442 		ext2_blkfree(ip, nb, fs->e2fs_bsize);
443 		blocksreleased += nblocks;
444 	}
445 
446 	/*
447 	 * Recursively free last partial block.
448 	 */
449 	if (level > SINGLE && lastbn >= 0) {
450 		last = lastbn % factor;
451 		nb = bap[i];
452 		if (nb != 0) {
453 			if ((error = ext2_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
454 			    last, level - 1, &blkcount)) != 0)
455 				allerror = error;
456 			blocksreleased += blkcount;
457 		}
458 	}
459 	free(copy, M_TEMP);
460 	*countp = blocksreleased;
461 	return (allerror);
462 }
463 
464 /*
465  *	discard preallocated blocks
466  */
467 int
468 ext2_inactive(ap)
469         struct vop_inactive_args /* {
470 		struct vnode *a_vp;
471 		struct thread *a_td;
472 	} */ *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(ap)
509 	struct vop_reclaim_args /* {
510 		struct vnode *a_vp;
511 		struct thread *a_td;
512 	} */ *ap;
513 {
514 	struct inode *ip;
515 	struct vnode *vp = ap->a_vp;
516 
517 	ip = VTOI(vp);
518 	if (ip->i_flag & IN_LAZYMOD) {
519 		ip->i_flag |= IN_MODIFIED;
520 		ext2_update(vp, 0);
521 	}
522 	vfs_hash_remove(vp);
523 	free(vp->v_data, M_EXT2NODE);
524 	vp->v_data = 0;
525 	vnode_destroy_vobject(vp);
526 	return (0);
527 }
528