xref: /original-bsd/sys/ufs/ffs/ffs_inode.c (revision e59fb703)
1 /*
2  * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)ffs_inode.c	7.45 (Berkeley) 12/19/91
8  */
9 
10 #include <sys/param.h>
11 #include <sys/systm.h>
12 #include <sys/mount.h>
13 #include <sys/proc.h>
14 #include <sys/file.h>
15 #include <sys/buf.h>
16 #include <sys/vnode.h>
17 #include <sys/kernel.h>
18 #include <sys/malloc.h>
19 
20 #include <ufs/ufs/quota.h>
21 #include <ufs/ufs/inode.h>
22 #include <ufs/ufs/ufsmount.h>
23 #include <ufs/ufs/ufs_extern.h>
24 
25 #include <ufs/ffs/fs.h>
26 #include <ufs/ffs/ffs_extern.h>
27 
28 static int ffs_indirtrunc __P((struct inode *, daddr_t, daddr_t, int, long *));
29 
30 extern u_long nextgennumber;
31 
32 int
33 ffs_init()
34 {
35 	return (ufs_init());
36 }
37 
38 /*
39  * Look up a UFS dinode number to find its incore vnode.
40  * If it is not in core, read it in from the specified device.
41  * If it is in core, wait for the lock bit to clear, then
42  * return the inode locked. Detection and handling of mount
43  * points must be done by the calling routine.
44  */
45 ffs_vget(mntp, ino, vpp)
46 	struct mount *mntp;
47 	ino_t ino;
48 	struct vnode **vpp;
49 {
50 	register struct fs *fs;
51 	register struct inode *ip;
52 	struct ufsmount *ump;
53 	struct buf *bp;
54 	struct dinode *dp;
55 	struct vnode *vp;
56 	union ihead *ih;
57 	dev_t dev;
58 	int i, type, error;
59 
60 	ump = VFSTOUFS(mntp);
61 	dev = ump->um_dev;
62 	if ((*vpp = ufs_ihashget(dev, ino)) != NULL)
63 		return (0);
64 
65 	/* Allocate a new vnode/inode. */
66 	if (error = getnewvnode(VT_UFS, mntp, &ffs_vnodeops, &vp)) {
67 		*vpp = NULL;
68 		return (error);
69 	}
70 	type = ump->um_devvp->v_tag == VT_MFS ? M_MFSNODE : M_FFSNODE; /* XXX */
71 	MALLOC(ip, struct inode *, sizeof(struct inode), type, M_WAITOK);
72 	vp->v_data = ip;
73 	ip->i_vnode = vp;
74 	ip->i_flag = 0;
75 	ip->i_devvp = 0;
76 	ip->i_mode = 0;
77 	ip->i_diroff = 0;
78 	ip->i_lockf = 0;
79 	ip->i_fs = fs = ump->um_fs;
80 	ip->i_dev = dev;
81 	ip->i_number = ino;
82 #ifdef QUOTA
83 	for (i = 0; i < MAXQUOTAS; i++)
84 		ip->i_dquot[i] = NODQUOT;
85 #endif
86 	/*
87 	 * Put it onto its hash chain and lock it so that other requests for
88 	 * this inode will block if they arrive while we are sleeping waiting
89 	 * for old data structures to be purged or for the contents of the
90 	 * disk portion of this inode to be read.
91 	 */
92 	ufs_ihashins(ip);
93 
94 	/* Read in the disk contents for the inode, copy into the inode. */
95 	if (error = bread(ump->um_devvp, fsbtodb(fs, itod(fs, ino)),
96 	    (int)fs->fs_bsize, NOCRED, &bp)) {
97 		/*
98 		 * The inode does not contain anything useful, so it would
99 		 * be misleading to leave it on its hash chain. It will be
100 		 * returned to the free list by ufs_iput().
101 		 */
102 		remque(ip);
103 		ip->i_forw = ip;
104 		ip->i_back = ip;
105 
106 		/* Unlock and discard unneeded inode. */
107 		ufs_iput(ip);
108 		brelse(bp);
109 		*vpp = NULL;
110 		return (error);
111 	}
112 	dp = bp->b_un.b_dino;
113 	dp += itoo(fs, ino);
114 	ip->i_din = *dp;
115 	brelse(bp);
116 
117 	/*
118 	 * Initialize the vnode from the inode, check for aliases.
119 	 * Note that the underlying vnode may have changed.
120 	 */
121 	if (error = ufs_vinit(mntp, &ffs_specops, FFS_FIFOOPS, &vp)) {
122 		ufs_iput(ip);
123 		*vpp = NULL;
124 		return (error);
125 	}
126 	/*
127 	 * Finish inode initialization now that aliasing has been resolved.
128 	 */
129 	ip->i_devvp = ump->um_devvp;
130 	VREF(ip->i_devvp);
131 	/*
132 	 * Set up a generation number for this inode if it does not
133 	 * already have one. This should only happen on old filesystems.
134 	 */
135 	if (ip->i_gen == 0) {
136 		if (++nextgennumber < (u_long)time.tv_sec)
137 			nextgennumber = time.tv_sec;
138 		ip->i_gen = nextgennumber;
139 		if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0)
140 			ip->i_flag |= IMOD;
141 	}
142 	*vpp = vp;
143 	return (0);
144 }
145 
146 /*
147  * Update the access, modified, and inode change times as specified
148  * by the IACC, IUPD, and ICHG flags respectively. The IMOD flag
149  * is used to specify that the inode needs to be updated but that
150  * the times have already been set. The access and modified times
151  * are taken from the second and third parameters; the inode change
152  * time is always taken from the current time. If waitfor is set,
153  * then wait for the disk write of the inode to complete.
154  */
155 int
156 ffs_update(vp, ta, tm, waitfor)
157 	register struct vnode *vp;
158 	struct timeval *ta, *tm;
159 	int waitfor;
160 {
161 	struct buf *bp;
162 	struct inode *ip;
163 	struct dinode *dp;
164 	register struct fs *fs;
165 	int error;
166 
167 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
168 		return (0);
169 	ip = VTOI(vp);
170 	if ((ip->i_flag & (IUPD|IACC|ICHG|IMOD)) == 0)
171 		return (0);
172 	if (ip->i_flag&IACC)
173 		ip->i_atime = ta->tv_sec;
174 	if (ip->i_flag&IUPD) {
175 		ip->i_mtime = tm->tv_sec;
176 		INCRQUAD(ip->i_modrev);
177 	}
178 	if (ip->i_flag&ICHG)
179 		ip->i_ctime = time.tv_sec;
180 	ip->i_flag &= ~(IUPD|IACC|ICHG|IMOD);
181 
182 	fs = ip->i_fs;
183 	if (error = bread(ip->i_devvp, fsbtodb(fs, itod(fs, ip->i_number)),
184 		(int)fs->fs_bsize, NOCRED, &bp)) {
185 		brelse(bp);
186 		return (error);
187 	}
188 	dp = bp->b_un.b_dino + itoo(fs, ip->i_number);
189 	*dp = ip->i_din;
190 	if (waitfor)
191 		return (bwrite(bp));
192 	else {
193 		bdwrite(bp);
194 		return (0);
195 	}
196 }
197 
198 #define	SINGLE	0	/* index of single indirect block */
199 #define	DOUBLE	1	/* index of double indirect block */
200 #define	TRIPLE	2	/* index of triple indirect block */
201 /*
202  * Truncate the inode ip to at most length size.  Free affected disk
203  * blocks -- the blocks of the file are removed in reverse order.
204  *
205  * NB: triple indirect blocks are untested.
206  */
207 ffs_truncate(ovp, length, flags)
208 	register struct vnode *ovp;
209 	u_long length;
210 	int flags;
211 {
212 	register daddr_t lastblock;
213 	register struct inode *oip;
214 	daddr_t bn, lbn, lastiblock[NIADDR];
215 	register struct fs *fs;
216 	register struct inode *ip;
217 	struct buf *bp;
218 	int offset, osize, size, level;
219 	long count, nblocks, blocksreleased = 0;
220 	register int i;
221 	int aflags, error, allerror;
222 	struct inode tip;
223 
224 	vnode_pager_setsize(ovp, length);
225 	oip = VTOI(ovp);
226 	if (oip->i_size <= length) {
227 		oip->i_flag |= ICHG|IUPD;
228 		error = ffs_update(ovp, &time, &time, 1);
229 		return (error);
230 	}
231 	/*
232 	 * Calculate index into inode's block list of
233 	 * last direct and indirect blocks (if any)
234 	 * which we want to keep.  Lastblock is -1 when
235 	 * the file is truncated to 0.
236 	 */
237 	fs = oip->i_fs;
238 	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
239 	lastiblock[SINGLE] = lastblock - NDADDR;
240 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
241 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
242 	nblocks = btodb(fs->fs_bsize);
243 	/*
244 	 * Update the size of the file. If the file is not being
245 	 * truncated to a block boundry, the contents of the
246 	 * partial block following the end of the file must be
247 	 * zero'ed in case it ever become accessable again because
248 	 * of subsequent file growth.
249 	 */
250 	osize = oip->i_size;
251 	offset = blkoff(fs, length);
252 	if (offset == 0) {
253 		oip->i_size = length;
254 	} else {
255 		lbn = lblkno(fs, length);
256 		aflags = B_CLRBUF;
257 		if (flags & IO_SYNC)
258 			aflags |= B_SYNC;
259 #ifdef QUOTA
260 		if (error = getinoquota(oip))
261 			return (error);
262 #endif
263 		if (error = ffs_balloc(oip, lbn, offset, &bp, aflags))
264 			return (error);
265 		oip->i_size = length;
266 		size = blksize(fs, oip, lbn);
267 		(void) vnode_pager_uncache(ITOV(oip));
268 		bzero(bp->b_un.b_addr + offset, (unsigned)(size - offset));
269 		allocbuf(bp, size);
270 		if (flags & IO_SYNC)
271 			bwrite(bp);
272 		else
273 			bdwrite(bp);
274 	}
275 	/*
276 	 * Update file and block pointers on disk before we start freeing
277 	 * blocks.  If we crash before free'ing blocks below, the blocks
278 	 * will be returned to the free list.  lastiblock values are also
279 	 * normalized to -1 for calls to ffs_indirtrunc below.
280 	 */
281 	tip = *oip;
282 	tip.i_size = osize;
283 	for (level = TRIPLE; level >= SINGLE; level--)
284 		if (lastiblock[level] < 0) {
285 			oip->i_ib[level] = 0;
286 			lastiblock[level] = -1;
287 		}
288 	for (i = NDADDR - 1; i > lastblock; i--)
289 		oip->i_db[i] = 0;
290 	oip->i_flag |= ICHG|IUPD;
291 	vinvalbuf(ITOV(oip), (length > 0));
292 	allerror = ffs_update(ovp, &time, &time, MNT_WAIT);
293 
294 	/*
295 	 * Indirect blocks first.
296 	 */
297 	ip = &tip;
298 	for (level = TRIPLE; level >= SINGLE; level--) {
299 		bn = ip->i_ib[level];
300 		if (bn != 0) {
301 			error = ffs_indirtrunc(ip,
302 			    bn, lastiblock[level], level, &count);
303 			if (error)
304 				allerror = error;
305 			blocksreleased += count;
306 			if (lastiblock[level] < 0) {
307 				ip->i_ib[level] = 0;
308 				ffs_blkfree(ip, bn, (off_t)fs->fs_bsize);
309 				blocksreleased += nblocks;
310 			}
311 		}
312 		if (lastiblock[level] >= 0)
313 			goto done;
314 	}
315 
316 	/*
317 	 * All whole direct blocks or frags.
318 	 */
319 	for (i = NDADDR - 1; i > lastblock; i--) {
320 		register off_t bsize;
321 
322 		bn = ip->i_db[i];
323 		if (bn == 0)
324 			continue;
325 		ip->i_db[i] = 0;
326 		bsize = (off_t)blksize(fs, ip, i);
327 		ffs_blkfree(ip, bn, bsize);
328 		blocksreleased += btodb(bsize);
329 	}
330 	if (lastblock < 0)
331 		goto done;
332 
333 	/*
334 	 * Finally, look for a change in size of the
335 	 * last direct block; release any frags.
336 	 */
337 	bn = ip->i_db[lastblock];
338 	if (bn != 0) {
339 		off_t oldspace, newspace;
340 
341 		/*
342 		 * Calculate amount of space we're giving
343 		 * back as old block size minus new block size.
344 		 */
345 		oldspace = blksize(fs, ip, lastblock);
346 		ip->i_size = length;
347 		newspace = blksize(fs, ip, lastblock);
348 		if (newspace == 0)
349 			panic("itrunc: newspace");
350 		if (oldspace - newspace > 0) {
351 			/*
352 			 * Block number of space to be free'd is
353 			 * the old block # plus the number of frags
354 			 * required for the storage we're keeping.
355 			 */
356 			bn += numfrags(fs, newspace);
357 			ffs_blkfree(ip, bn, oldspace - newspace);
358 			blocksreleased += btodb(oldspace - newspace);
359 		}
360 	}
361 done:
362 /* BEGIN PARANOIA */
363 	for (level = SINGLE; level <= TRIPLE; level++)
364 		if (ip->i_ib[level] != oip->i_ib[level])
365 			panic("itrunc1");
366 	for (i = 0; i < NDADDR; i++)
367 		if (ip->i_db[i] != oip->i_db[i])
368 			panic("itrunc2");
369 /* END PARANOIA */
370 	oip->i_blocks -= blocksreleased;
371 	if (oip->i_blocks < 0)			/* sanity */
372 		oip->i_blocks = 0;
373 	oip->i_flag |= ICHG;
374 #ifdef QUOTA
375 	if (!getinoquota(oip))
376 		(void) chkdq(oip, -blocksreleased, NOCRED, 0);
377 #endif
378 	return (allerror);
379 }
380 
381 /*
382  * Release blocks associated with the inode ip and stored in the indirect
383  * block bn.  Blocks are free'd in LIFO order up to (but not including)
384  * lastbn.  If level is greater than SINGLE, the block is an indirect block
385  * and recursive calls to indirtrunc must be used to cleanse other indirect
386  * blocks.
387  *
388  * NB: triple indirect blocks are untested.
389  */
390 static int
391 ffs_indirtrunc(ip, bn, lastbn, level, countp)
392 	register struct inode *ip;
393 	daddr_t bn, lastbn;
394 	int level;
395 	long *countp;
396 {
397 	register int i;
398 	struct buf *bp;
399 	register struct fs *fs = ip->i_fs;
400 	register daddr_t *bap;
401 	daddr_t *copy, nb, last;
402 	long blkcount, factor;
403 	int nblocks, blocksreleased = 0;
404 	int error, allerror = 0;
405 
406 	/*
407 	 * Calculate index in current block of last
408 	 * block to be kept.  -1 indicates the entire
409 	 * block so we need not calculate the index.
410 	 */
411 	factor = 1;
412 	for (i = SINGLE; i < level; i++)
413 		factor *= NINDIR(fs);
414 	last = lastbn;
415 	if (lastbn > 0)
416 		last /= factor;
417 	nblocks = btodb(fs->fs_bsize);
418 	/*
419 	 * Get buffer of block pointers, zero those
420 	 * entries corresponding to blocks to be free'd,
421 	 * and update on disk copy first.
422 	 */
423 	error = bread(ip->i_devvp, fsbtodb(fs, bn), (int)fs->fs_bsize,
424 		NOCRED, &bp);
425 	if (error) {
426 		brelse(bp);
427 		*countp = 0;
428 		return (error);
429 	}
430 	bap = bp->b_un.b_daddr;
431 	MALLOC(copy, daddr_t *, fs->fs_bsize, M_TEMP, M_WAITOK);
432 	bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->fs_bsize);
433 	bzero((caddr_t)&bap[last + 1],
434 	  (u_int)(NINDIR(fs) - (last + 1)) * sizeof (daddr_t));
435 	if (last == -1)
436 		bp->b_flags |= B_INVAL;
437 	error = bwrite(bp);
438 	if (error)
439 		allerror = error;
440 	bap = copy;
441 
442 	/*
443 	 * Recursively free totally unused blocks.
444 	 */
445 	for (i = NINDIR(fs) - 1; i > last; i--) {
446 		nb = bap[i];
447 		if (nb == 0)
448 			continue;
449 		if (level > SINGLE) {
450 			if (error = ffs_indirtrunc(ip,
451 			    nb, (daddr_t)-1, level - 1, &blkcount))
452 				allerror = error;
453 			blocksreleased += blkcount;
454 		}
455 		ffs_blkfree(ip, nb, (off_t)fs->fs_bsize);
456 		blocksreleased += nblocks;
457 	}
458 
459 	/*
460 	 * Recursively free last partial block.
461 	 */
462 	if (level > SINGLE && lastbn >= 0) {
463 		last = lastbn % factor;
464 		nb = bap[i];
465 		if (nb != 0) {
466 			if (error =
467 			    ffs_indirtrunc(ip, nb, last, level - 1, &blkcount))
468 				allerror = error;
469 			blocksreleased += blkcount;
470 		}
471 	}
472 	FREE(copy, M_TEMP);
473 	*countp = blocksreleased;
474 	return (allerror);
475 }
476