xref: /original-bsd/sys/ufs/lfs/lfs_inode.c (revision eda27992)
1 /*
2  * Copyright (c) 1986, 1989, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)lfs_inode.c	8.9 (Berkeley) 05/08/95
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 /* Search a block for a specific dinode. */
31 struct dinode *
lfs_ifind(fs,ino,dip)32 lfs_ifind(fs, ino, dip)
33 	struct lfs *fs;
34 	ino_t ino;
35 	register struct dinode *dip;
36 {
37 	register int cnt;
38 	register struct dinode *ldip;
39 
40 	for (cnt = INOPB(fs), ldip = dip + (cnt - 1); cnt--; --ldip)
41 		if (ldip->di_inumber == ino)
42 			return (ldip);
43 
44 	panic("lfs_ifind: dinode %u not found", ino);
45 	/* NOTREACHED */
46 }
47 
48 int
lfs_update(ap)49 lfs_update(ap)
50 	struct vop_update_args /* {
51 		struct vnode *a_vp;
52 		struct timeval *a_access;
53 		struct timeval *a_modify;
54 		int a_waitfor;
55 	} */ *ap;
56 {
57 	struct vnode *vp = ap->a_vp;
58 	struct inode *ip;
59 
60 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
61 		return (0);
62 	ip = VTOI(vp);
63 	if ((ip->i_flag &
64 	    (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0)
65 		return (0);
66 	if (ip->i_flag & IN_ACCESS)
67 		ip->i_atime = ap->a_access->tv_sec;
68 	if (ip->i_flag & IN_UPDATE) {
69 		ip->i_mtime = ap->a_modify->tv_sec;
70 		(ip)->i_modrev++;
71 	}
72 	if (ip->i_flag & IN_CHANGE)
73 		ip->i_ctime = time.tv_sec;
74 	ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
75 
76 	if (!(ip->i_flag & IN_MODIFIED))
77 		++(VFSTOUFS(vp->v_mount)->um_lfs->lfs_uinodes);
78 	ip->i_flag |= IN_MODIFIED;
79 
80 	/* If sync, push back the vnode and any dirty blocks it may have. */
81 	return (ap->a_waitfor & LFS_SYNC ? lfs_vflush(vp) : 0);
82 }
83 
84 /* Update segment usage information when removing a block. */
85 #define UPDATE_SEGUSE \
86 	if (lastseg != -1) { \
87 		LFS_SEGENTRY(sup, fs, lastseg, sup_bp); \
88 		if (num > sup->su_nbytes) \
89 			panic("lfs_truncate: negative bytes in segment %d\n", \
90 			    lastseg); \
91 		sup->su_nbytes -= num; \
92 		e1 = VOP_BWRITE(sup_bp); \
93 		fragsreleased += numfrags(fs, num); \
94 	}
95 
96 #define SEGDEC(S) { \
97 	if (daddr != 0) { \
98 		if (lastseg != (seg = datosn(fs, daddr))) { \
99 			UPDATE_SEGUSE; \
100 			num = (S); \
101 			lastseg = seg; \
102 		} else \
103 			num += (S); \
104 	} \
105 }
106 
107 /*
108  * Truncate the inode ip to at most length size.  Update segment usage
109  * table information.
110  */
111 /* ARGSUSED */
112 int
lfs_truncate(ap)113 lfs_truncate(ap)
114 	struct vop_truncate_args /* {
115 		struct vnode *a_vp;
116 		off_t a_length;
117 		int a_flags;
118 		struct ucred *a_cred;
119 		struct proc *a_p;
120 	} */ *ap;
121 {
122 	register struct indir *inp;
123 	register int i;
124 	register ufs_daddr_t *daddrp;
125 	register struct vnode *vp = ap->a_vp;
126 	off_t length = ap->a_length;
127 	struct buf *bp, *sup_bp;
128 	struct timeval tv;
129 	struct ifile *ifp;
130 	struct inode *ip;
131 	struct lfs *fs;
132 	struct indir a[NIADDR + 2], a_end[NIADDR + 2];
133 	SEGUSE *sup;
134   	ufs_daddr_t daddr, lastblock, lbn, olastblock;
135 	ufs_daddr_t oldsize_lastblock, oldsize_newlast, newsize;
136 	long off, a_released, fragsreleased, i_released;
137 	int e1, e2, depth, lastseg, num, offset, seg, freesize;
138 
139 	ip = VTOI(vp);
140 	tv = time;
141 	if (vp->v_type == VLNK && vp->v_mount->mnt_maxsymlinklen > 0) {
142 #ifdef DIAGNOSTIC
143 		if (length != 0)
144 			panic("lfs_truncate: partial truncate of symlink");
145 #endif
146 		bzero((char *)&ip->i_shortlink, (u_int)ip->i_size);
147 		ip->i_size = 0;
148 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
149 		return (VOP_UPDATE(vp, &tv, &tv, 0));
150 	}
151 	vnode_pager_setsize(vp, (u_long)length);
152 
153 	fs = ip->i_lfs;
154 
155 	/* If length is larger than the file, just update the times. */
156 	if (ip->i_size <= length) {
157 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
158 		return (VOP_UPDATE(vp, &tv, &tv, 0));
159 	}
160 
161 	/*
162 	 * Calculate index into inode's block list of last direct and indirect
163 	 * blocks (if any) which we want to keep.  Lastblock is 0 when the
164 	 * file is truncated to 0.
165 	 */
166 	lastblock = lblkno(fs, length + fs->lfs_bsize - 1);
167 	olastblock = lblkno(fs, ip->i_size + fs->lfs_bsize - 1) - 1;
168 
169 	/*
170 	 * Update the size of the file. If the file is not being truncated to
171 	 * a block boundry, the contents of the partial block following the end
172 	 * of the file must be zero'ed in case it ever become accessable again
173 	 * because of subsequent file growth.  For this part of the code,
174 	 * oldsize_newlast refers to the old size of the new last block in the file.
175 	 */
176 	offset = blkoff(fs, length);
177 	lbn = lblkno(fs, length);
178 	oldsize_newlast = blksize(fs, ip, lbn);
179 
180 	/* Now set oldsize to the current size of the current last block */
181 	oldsize_lastblock = blksize(fs, ip, olastblock);
182 	if (offset == 0)
183 		ip->i_size = length;
184 	else {
185 #ifdef QUOTA
186 		if (e1 = getinoquota(ip))
187 			return (e1);
188 #endif
189 		if (e1 = bread(vp, lbn, oldsize_newlast, NOCRED, &bp))
190 			return (e1);
191 		ip->i_size = length;
192 		(void)vnode_pager_uncache(vp);
193 		newsize = blksize(fs, ip, lbn);
194 		bzero((char *)bp->b_data + offset, (u_int)(newsize - offset));
195 		allocbuf(bp, newsize);
196 		if (e1 = VOP_BWRITE(bp))
197 			return (e1);
198 	}
199 	/*
200 	 * Modify sup->su_nbyte counters for each deleted block; keep track
201 	 * of number of blocks removed for ip->i_blocks.
202 	 */
203 	fragsreleased = 0;
204 	num = 0;
205 	lastseg = -1;
206 
207 	for (lbn = olastblock; lbn >= lastblock;) {
208 		/* XXX use run length from bmap array to make this faster */
209 		ufs_bmaparray(vp, lbn, &daddr, a, &depth, NULL);
210 		if (lbn == olastblock) {
211 			for (i = NIADDR + 2; i--;)
212 				a_end[i] = a[i];
213 			freesize = oldsize_lastblock;
214 		} else
215 			freesize = fs->lfs_bsize;
216 
217 		switch (depth) {
218 		case 0:				/* Direct block. */
219 			daddr = ip->i_db[lbn];
220 			SEGDEC(freesize);
221 			ip->i_db[lbn] = 0;
222 			--lbn;
223 			break;
224 #ifdef DIAGNOSTIC
225 		case 1:				/* An indirect block. */
226 			panic("lfs_truncate: ufs_bmaparray returned depth 1");
227 			/* NOTREACHED */
228 #endif
229 		default:			/* Chain of indirect blocks. */
230 			inp = a + --depth;
231 			if (inp->in_off > 0 && lbn != lastblock) {
232 				lbn -= inp->in_off < lbn - lastblock ?
233 				    inp->in_off : lbn - lastblock;
234 				break;
235 			}
236 			for (; depth && (inp->in_off == 0 || lbn == lastblock);
237 			    --inp, --depth) {
238 				if (bread(vp,
239 				    inp->in_lbn, fs->lfs_bsize, NOCRED, &bp))
240 					panic("lfs_truncate: bread bno %d",
241 					    inp->in_lbn);
242 				daddrp = (ufs_daddr_t *)bp->b_data +
243 				    inp->in_off;
244 				for (i = inp->in_off;
245 				    i++ <= a_end[depth].in_off;) {
246 					daddr = *daddrp++;
247 					SEGDEC(freesize);
248 				}
249 				a_end[depth].in_off = NINDIR(fs) - 1;
250 				if (inp->in_off == 0)
251 					brelse (bp);
252 				else {
253 					bzero((ufs_daddr_t *)bp->b_data +
254 					    inp->in_off, fs->lfs_bsize -
255 					    inp->in_off * sizeof(ufs_daddr_t));
256 					if (e1 = VOP_BWRITE(bp))
257 						return (e1);
258 				}
259 			}
260 			if (depth == 0 && a[1].in_off == 0) {
261 				off = a[0].in_off;
262 				daddr = ip->i_ib[off];
263 				SEGDEC(freesize);
264 				ip->i_ib[off] = 0;
265 			}
266 			if (lbn == lastblock || lbn <= NDADDR)
267 				--lbn;
268 			else {
269 				lbn -= NINDIR(fs);
270 				if (lbn < lastblock)
271 					lbn = lastblock;
272 			}
273 		}
274 	}
275 	UPDATE_SEGUSE;
276 
277 	/* If truncating the file to 0, update the version number. */
278 	if (length == 0) {
279 		LFS_IENTRY(ifp, fs, ip->i_number, bp);
280 		++ifp->if_version;
281 		(void) VOP_BWRITE(bp);
282 	}
283 
284 #ifdef DIAGNOSTIC
285 	if (ip->i_blocks < fragstodb(fs, fragsreleased)) {
286 		printf("lfs_truncate: frag count < 0\n");
287 		fragsreleased = dbtofrags(fs, ip->i_blocks);
288 		panic("lfs_truncate: frag count < 0\n");
289 	}
290 #endif
291 	ip->i_blocks -= fragstodb(fs, fragsreleased);
292 	fs->lfs_bfree +=  fragstodb(fs, fragsreleased);
293 	ip->i_flag |= IN_CHANGE | IN_UPDATE;
294 	/*
295 	 * Traverse dirty block list counting number of dirty buffers
296 	 * that are being deleted out of the cache, so that the lfs_avail
297 	 * field can be updated.
298 	 */
299 	a_released = 0;
300 	i_released = 0;
301 	for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = bp->b_vnbufs.le_next)
302 		if (bp->b_flags & B_LOCKED) {
303 			a_released += numfrags(fs, bp->b_bcount);
304 			/*
305 			 * XXX
306 			 * When buffers are created in the cache, their block
307 			 * number is set equal to their logical block number.
308 			 * If that is still true, we are assuming that the
309 			 * blocks are new (not yet on disk) and weren't
310 			 * counted above.  However, there is a slight chance
311 			 * that a block's disk address is equal to its logical
312 			 * block number in which case, we'll get an overcounting
313 			 * here.
314 			 */
315 			if (bp->b_blkno == bp->b_lblkno)
316 				i_released += numfrags(fs, bp->b_bcount);
317 		}
318 	fragsreleased = i_released;
319 #ifdef DIAGNOSTIC
320 	if (fragsreleased > dbtofrags(fs, ip->i_blocks)) {
321 		printf("lfs_inode: Warning! %s\n",
322 		    "more frags released from inode than are in inode");
323 		fragsreleased = dbtofrags(fs, ip->i_blocks);
324 		panic("lfs_inode: Warning.  More frags released\n");
325 	}
326 #endif
327 	fs->lfs_bfree += fragstodb(fs, fragsreleased);
328 	ip->i_blocks -= fragstodb(fs, fragsreleased);
329 #ifdef DIAGNOSTIC
330 	if (length == 0 && ip->i_blocks != 0) {
331 		printf("lfs_inode: Warning! %s%d%s\n",
332 		    "Truncation to zero, but ", ip->i_blocks,
333 		    " blocks left on inode");
334 		panic("lfs_inode");
335 	}
336 #endif
337 	fs->lfs_avail += fragstodb(fs, a_released);
338 	e1 = vinvalbuf(vp, (length > 0) ? V_SAVE : 0, ap->a_cred, ap->a_p,
339 	    0, 0);
340 	e2 = VOP_UPDATE(vp, &tv, &tv, 0);
341 	return (e1 ? e1 : e2 ? e2 : 0);
342 }
343