xref: /original-bsd/sys/ufs/lfs/lfs_inode.c (revision 0958d343)
1 /*
2  * Copyright (c) 1986, 1989, 1991 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)lfs_inode.c	7.69 (Berkeley) 06/23/92
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 <vm/vm.h>
21 
22 #include <ufs/ufs/quota.h>
23 #include <ufs/ufs/inode.h>
24 #include <ufs/ufs/ufsmount.h>
25 #include <ufs/ufs/ufs_extern.h>
26 
27 #include <ufs/lfs/lfs.h>
28 #include <ufs/lfs/lfs_extern.h>
29 
30 static struct dinode *lfs_ifind __P((struct lfs *, ino_t, struct dinode *));
31 
32 int
33 lfs_init()
34 {
35 #ifdef VERBOSE
36 	printf("lfs_init\n");
37 #endif
38 	return (ufs_init());
39 }
40 
41 /*
42  * Look up an LFS dinode number to find its incore vnode.  If not already
43  * in core, read it in from the specified device.  Return the inode locked.
44  * Detection and handling of mount points must be done by the calling routine.
45  */
46 int
47 lfs_vget (ap)
48 	struct vop_vget_args *ap;
49 {
50 	register struct lfs *fs;
51 	register struct inode *ip;
52 	struct buf *bp;
53 	struct ifile *ifp;
54 	struct vnode *vp;
55 	struct ufsmount *ump;
56 	daddr_t daddr;
57 	dev_t dev;
58 	int error;
59 
60 #ifdef VERBOSE
61 	printf("lfs_vget\n");
62 #endif
63 	ump = VFSTOUFS(ap->a_mp);
64 	dev = ump->um_dev;
65 	if ((*ap->a_vpp = ufs_ihashget(dev, ap->a_ino)) != NULL)
66 		return (0);
67 
68 	/* Translate the inode number to a disk address. */
69 	fs = ump->um_lfs;
70 	if (ap->a_ino == LFS_IFILE_INUM)
71 		daddr = fs->lfs_idaddr;
72 	else {
73 		LFS_IENTRY(ifp, fs, ap->a_ino, bp);
74 		daddr = ifp->if_daddr;
75 		brelse(bp);
76 		if (daddr == LFS_UNUSED_DADDR)
77 			return (ENOENT);
78 	}
79 
80 	/* Allocate new vnode/inode. */
81 	if (error = lfs_vcreate(ap->a_mp, ap->a_ino, &vp)) {
82 		*ap->a_vpp = NULL;
83 		return (error);
84 	}
85 
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 	ip = VTOI(vp);
93 	ufs_ihashins(ip);
94 
95 	/*
96 	 * XXX
97 	 * This may not need to be here, logically it should go down with
98 	 * the i_devvp initialization.
99 	 * Ask Kirk.
100 	 */
101 	ip->i_lfs = ump->um_lfs;
102 
103 	/* Read in the disk contents for the inode, copy into the inode. */
104 	if (error =
105 	    bread(ump->um_devvp, daddr, (int)fs->lfs_bsize, NOCRED, &bp)) {
106 		/*
107 		 * The inode does not contain anything useful, so it
108 		 * would be misleading to leave it on its hash chain.
109 		 * Iput() will return it to the free list.
110 		 */
111 		remque(ip);
112 		ip->i_forw = ip;
113 		ip->i_back = ip;
114 
115 		/* Unlock and discard unneeded inode. */
116 		ufs_iput(ip);
117 		brelse(bp);
118 		*ap->a_vpp = NULL;
119 		return (error);
120 	}
121 	ip->i_din = *lfs_ifind(fs, ap->a_ino, bp->b_un.b_dino);
122 	brelse(bp);
123 
124 	/*
125 	 * Initialize the vnode from the inode, check for aliases.  In all
126 	 * cases re-init ip, the underlying vnode/inode may have changed.
127 	 */
128 	if (error = ufs_vinit(ap->a_mp, lfs_specop_p, LFS_FIFOOPS, &vp)) {
129 		ufs_iput(ip);
130 		*ap->a_vpp = NULL;
131 		return (error);
132 	}
133 	/*
134 	 * Finish inode initialization now that aliasing has been resolved.
135 	 */
136 	ip->i_devvp = ump->um_devvp;
137 	VREF(ip->i_devvp);
138 	*ap->a_vpp = vp;
139 	return (0);
140 }
141 
142 /* Search a block for a specific dinode. */
143 static struct dinode *
144 lfs_ifind(fs, ino, dip)
145 	struct lfs *fs;
146 	ino_t ino;
147 	register struct dinode *dip;
148 {
149 	register int cnt;
150 	register struct dinode *ldip;
151 
152 #ifdef VERBOSE
153 	printf("lfs_ifind: inode %d\n", ino);
154 #endif
155 	for (cnt = INOPB(fs), ldip = dip + (cnt - 1); cnt--; --ldip)
156 		if (ldip->di_inum == ino)
157 			return (ldip);
158 
159 	panic("lfs_ifind: dinode %u not found", ino);
160 	/* NOTREACHED */
161 }
162 
163 int
164 lfs_update (ap)
165 	struct vop_update_args *ap;
166 {
167 	struct vnode *vp = ap->a_vp;
168 	struct inode *ip;
169 
170 #ifdef VERBOSE
171 	printf("lfs_update\n");
172 #endif
173 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
174 		return (0);
175 	ip = VTOI(vp);
176 	if ((ip->i_flag & (IUPD|IACC|ICHG|IMOD)) == 0)
177 		return (0);
178 	if (ip->i_flag&IACC)
179 		ip->i_atime.ts_sec = ap->a_ta->tv_sec;
180 	if (ip->i_flag&IUPD) {
181 		ip->i_mtime.ts_sec = ap->a_tm->tv_sec;
182 		(ip)->i_modrev++;
183 	}
184 	if (ip->i_flag&ICHG)
185 		ip->i_ctime.ts_sec = time.tv_sec;
186 	ip->i_flag &= ~(IUPD|IACC|ICHG|IMOD);
187 
188 	/* Push back the vnode and any dirty blocks it may have. */
189 	return (ap->a_waitfor ? lfs_vflush(vp) : 0);
190 }
191 
192 /* Update segment usage information when removing a block. */
193 #define UPDATE_SEGUSE \
194 	if (lastseg != -1) { \
195 		LFS_SEGENTRY(sup, fs, lastseg, sup_bp); \
196 		sup->su_nbytes -= num << fs->lfs_bshift; \
197 		LFS_UBWRITE(sup_bp); \
198 		blocksreleased += num; \
199 	}
200 
201 #define SEGDEC { \
202 	if (daddr != UNASSIGNED) { \
203 		if (lastseg != (seg = datosn(fs, daddr))) { \
204 			UPDATE_SEGUSE; \
205 			num = 1; \
206 			lastseg = seg; \
207 		} else \
208 			++num; \
209 	} \
210 }
211 
212 /*
213  * Truncate the inode ip to at most length size.  Update segment usage
214  * table information.
215  */
216 /* ARGSUSED */
217 int
218 lfs_truncate (ap)
219 	struct vop_truncate_args *ap;
220 {
221 	USES_VOP_UPDATE;
222 	register INDIR *inp;
223 	register int i;
224 	register daddr_t *daddrp;
225 	struct buf *bp, *sup_bp;
226 	struct ifile *ifp;
227 	struct inode *ip;
228 	struct lfs *fs;
229 	INDIR a[NIADDR + 2], a_end[NIADDR + 2];
230 	SEGUSE *sup;
231 	daddr_t daddr, lastblock, lbn, olastblock;
232 	long off, blocksreleased;
233 	int error, depth, lastseg, num, offset, seg, size;
234 
235 #ifdef VERBOSE
236 	printf("lfs_truncate\n");
237 #endif
238 	vnode_pager_setsize(ap->a_vp, (u_long)ap->a_length);
239 
240 	ip = VTOI(ap->a_vp);
241 	fs = ip->i_lfs;
242 
243 	/* If truncating the file to 0, update the version number. */
244 	if (ap->a_length == 0) {
245 		LFS_IENTRY(ifp, fs, ip->i_number, bp);
246 		++ifp->if_version;
247 		LFS_UBWRITE(bp);
248 	}
249 
250 	/* If ap->a_length is larger than the file, just update the times. */
251 	if (ip->i_size <= ap->a_length) {
252 		ip->i_flag |= ICHG|IUPD;
253 		return (VOP_UPDATE(ap->a_vp, &time, &time, 1));
254 	}
255 
256 	/*
257 	 * Calculate index into inode's block list of last direct and indirect
258 	 * blocks (if any) which we want to keep.  Lastblock is 0 when the
259 	 * file is truncated to 0.
260 	 */
261 	lastblock = lblkno(fs, ap->a_length + fs->lfs_bsize - 1);
262 	olastblock = lblkno(fs, ip->i_size + fs->lfs_bsize - 1) - 1;
263 
264 	/*
265 	 * Update the size of the file. If the file is not being truncated to
266 	 * a block boundry, the contents of the partial block following the end
267 	 * of the file must be zero'ed in case it ever become accessable again
268 	 * because of subsequent file growth.
269 	 */
270 	offset = blkoff(fs, ap->a_length);
271 	if (offset == 0)
272 		ip->i_size = ap->a_length;
273 	else {
274 		lbn = lblkno(fs, ap->a_length);
275 #ifdef QUOTA
276 		if (error = getinoquota(ip))
277 			return (error);
278 #endif
279 		if (error = bread(ap->a_vp, lbn, fs->lfs_bsize, NOCRED, &bp))
280 			return (error);
281 		ip->i_size = ap->a_length;
282 		size = blksize(fs);
283 		(void)vnode_pager_uncache(ap->a_vp);
284 		bzero(bp->b_un.b_addr + offset, (unsigned)(size - offset));
285 		allocbuf(bp, size);
286 		LFS_UBWRITE(bp);
287 	}
288 	/*
289 	 * Modify sup->su_nbyte counters for each deleted block; keep track
290 	 * of number of blocks removed for ip->i_blocks.
291 	 */
292 	blocksreleased = 0;
293 	num = 0;
294 	lastseg = -1;
295 
296 	for (lbn = olastblock; lbn >= lastblock;) {
297 		lfs_bmaparray(ap->a_vp, lbn, &daddr, a, &depth);
298 		if (lbn == olastblock)
299 			for (i = NIADDR + 2; i--;)
300 				a_end[i] = a[i];
301 		switch (depth) {
302 		case 0:				/* Direct block. */
303 			daddr = ip->i_db[lbn];
304 			SEGDEC;
305 			ip->i_db[lbn] = 0;
306 			--lbn;
307 			break;
308 #ifdef DIAGNOSTIC
309 		case 1:				/* An indirect block. */
310 			panic("lfs_truncate: lfs_bmaparray returned depth 1");
311 			/* NOTREACHED */
312 #endif
313 		default:			/* Chain of indirect blocks. */
314 			inp = a + --depth;
315 			if (inp->in_off > 0 && lbn != lastblock) {
316 				lbn -= inp->in_off < lbn - lastblock ?
317 				    inp->in_off : lbn - lastblock;
318 				break;
319 			}
320 			for (; depth && (inp->in_off == 0 || lbn == lastblock);
321 			    --inp, --depth) {
322 				/*
323 				 * XXX
324 				 * The indirect block may not yet exist, so
325 				 * bread will create one just so we can free
326 				 * it.
327 				 */
328 				if (bread(ap->a_vp,
329 				    inp->in_lbn, fs->lfs_bsize, NOCRED, &bp))
330 					panic("lfs_truncate: bread bno %d",
331 					    inp->in_lbn);
332 				daddrp = bp->b_un.b_daddr + inp->in_off;
333 				for (i = inp->in_off;
334 				    i++ <= a_end[depth].in_off;) {
335 					daddr = *daddrp++;
336 					SEGDEC;
337 				}
338 				a_end[depth].in_off = NINDIR(fs) - 1;
339 				if (inp->in_off == 0)
340 					brelse (bp);
341 				else {
342 					bzero(bp->b_un.b_daddr + inp->in_off,
343 					    fs->lfs_bsize -
344 					    inp->in_off * sizeof(daddr_t));
345 					LFS_UBWRITE(bp);
346 				}
347 			}
348 			if (depth == 0 && a[1].in_off == 0) {
349 				off = a[0].in_off;
350 				daddr = ip->i_ib[off];
351 				SEGDEC;
352 				ip->i_ib[off] = 0;
353 			}
354 			if (lbn == lastblock || lbn <= NDADDR)
355 				--lbn;
356 			else {
357 				lbn -= NINDIR(fs);
358 				if (lbn < lastblock)
359 					lbn = lastblock;
360 			}
361 		}
362 	}
363 	UPDATE_SEGUSE;
364 	ip->i_blocks -= blocksreleased;
365 	/*
366 	 * XXX
367 	 * Currently, we don't know when we allocate an indirect block, so
368 	 * ip->i_blocks isn't getting incremented appropriately.  As a result,
369 	 * when we delete any indirect blocks, we get a bad number here.
370 	 */
371 	if (ip->i_blocks < 0)
372 		ip->i_blocks = 0;
373 	ip->i_flag |= ICHG|IUPD;
374 	(void)vinvalbuf(ap->a_vp, ap->a_length > 0);
375 	error = VOP_UPDATE(ap->a_vp, &time, &time, MNT_WAIT);
376 	return (0);
377 }
378