xref: /freebsd/sys/ufs/ffs/ffs_balloc.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
1 /*
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)ffs_balloc.c	8.4 (Berkeley) 9/23/93
34  */
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/buf.h>
39 #include <sys/proc.h>
40 #include <sys/file.h>
41 #include <sys/vnode.h>
42 
43 #include <vm/vm.h>
44 
45 #include <ufs/ufs/quota.h>
46 #include <ufs/ufs/inode.h>
47 #include <ufs/ufs/ufs_extern.h>
48 
49 #include <ufs/ffs/fs.h>
50 #include <ufs/ffs/ffs_extern.h>
51 
52 /*
53  * Balloc defines the structure of file system storage
54  * by allocating the physical blocks on a device given
55  * the inode and the logical block number in a file.
56  */
57 int
58 ffs_balloc(ip, bn, size, cred, bpp, flags)
59 	register struct inode *ip;
60 	register daddr_t bn;
61 	int size;
62 	struct ucred *cred;
63 	struct buf **bpp;
64 	int flags;
65 {
66 	register struct fs *fs;
67 	register daddr_t nb;
68 	struct buf *bp, *nbp;
69 	struct vnode *vp = ITOV(ip);
70 	struct indir indirs[NIADDR + 2];
71 	daddr_t newb, lbn, *bap, pref;
72 	int osize, nsize, num, i, error;
73 
74 	*bpp = NULL;
75 	if (bn < 0)
76 		return (EFBIG);
77 	fs = ip->i_fs;
78 	lbn = bn;
79 
80 	/*
81 	 * If the next write will extend the file into a new block,
82 	 * and the file is currently composed of a fragment
83 	 * this fragment has to be extended to be a full block.
84 	 */
85 	nb = lblkno(fs, ip->i_size);
86 	if (nb < NDADDR && nb < bn) {
87 		osize = blksize(fs, ip, nb);
88 		if (osize < fs->fs_bsize && osize > 0) {
89 			error = ffs_realloccg(ip, nb,
90 				ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]),
91 				osize, (int)fs->fs_bsize, cred, &bp);
92 			if (error)
93 				return (error);
94 			ip->i_size = (nb + 1) * fs->fs_bsize;
95 			vnode_pager_setsize(vp, (u_long)ip->i_size);
96 			ip->i_db[nb] = dbtofsb(fs, bp->b_blkno);
97 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
98 			if (flags & B_SYNC)
99 				bwrite(bp);
100 			else
101 				bawrite(bp);
102 		}
103 	}
104 	/*
105 	 * The first NDADDR blocks are direct blocks
106 	 */
107 	if (bn < NDADDR) {
108 		nb = ip->i_db[bn];
109 		if (nb != 0 && ip->i_size >= (bn + 1) * fs->fs_bsize) {
110 			error = bread(vp, bn, fs->fs_bsize, NOCRED, &bp);
111 			if (error) {
112 				brelse(bp);
113 				return (error);
114 			}
115 			*bpp = bp;
116 			return (0);
117 		}
118 		if (nb != 0) {
119 			/*
120 			 * Consider need to reallocate a fragment.
121 			 */
122 			osize = fragroundup(fs, blkoff(fs, ip->i_size));
123 			nsize = fragroundup(fs, size);
124 			if (nsize <= osize) {
125 				error = bread(vp, bn, osize, NOCRED, &bp);
126 				if (error) {
127 					brelse(bp);
128 					return (error);
129 				}
130 			} else {
131 				error = ffs_realloccg(ip, bn,
132 				    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
133 				    osize, nsize, cred, &bp);
134 				if (error)
135 					return (error);
136 			}
137 		} else {
138 			if (ip->i_size < (bn + 1) * fs->fs_bsize)
139 				nsize = fragroundup(fs, size);
140 			else
141 				nsize = fs->fs_bsize;
142 			error = ffs_alloc(ip, bn,
143 			    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
144 			    nsize, cred, &newb);
145 			if (error)
146 				return (error);
147 			bp = getblk(vp, bn, nsize, 0, 0);
148 			bp->b_blkno = fsbtodb(fs, newb);
149 			if (flags & B_CLRBUF)
150 				clrbuf(bp);
151 		}
152 		ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
153 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
154 		*bpp = bp;
155 		return (0);
156 	}
157 	/*
158 	 * Determine the number of levels of indirection.
159 	 */
160 	pref = 0;
161 	if (error = ufs_getlbns(vp, bn, indirs, &num))
162 		return(error);
163 #ifdef DIAGNOSTIC
164 	if (num < 1)
165 		panic ("ffs_balloc: ufs_bmaparray returned indirect block\n");
166 #endif
167 	/*
168 	 * Fetch the first indirect block allocating if necessary.
169 	 */
170 	--num;
171 	nb = ip->i_ib[indirs[0].in_off];
172 	if (nb == 0) {
173 		pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
174 	        if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize,
175 		    cred, &newb))
176 			return (error);
177 		nb = newb;
178 		bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0);
179 		bp->b_blkno = fsbtodb(fs, newb);
180 		clrbuf(bp);
181 		/*
182 		 * Write synchronously so that indirect blocks
183 		 * never point at garbage.
184 		 */
185 		if (error = bwrite(bp)) {
186 			ffs_blkfree(ip, nb, fs->fs_bsize);
187 			return (error);
188 		}
189 		ip->i_ib[indirs[0].in_off] = newb;
190 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
191 	}
192 	/*
193 	 * Fetch through the indirect blocks, allocating as necessary.
194 	 */
195 	for (i = 1;;) {
196 		error = bread(vp,
197 		    indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp);
198 		if (error) {
199 			brelse(bp);
200 			return (error);
201 		}
202 		bap = (daddr_t *)bp->b_data;
203 		nb = bap[indirs[i].in_off];
204 		if (i == num)
205 			break;
206 		i += 1;
207 		if (nb != 0) {
208 			brelse(bp);
209 			continue;
210 		}
211 		if (pref == 0)
212 			pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
213 		if (error =
214 		    ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
215 			brelse(bp);
216 			return (error);
217 		}
218 		nb = newb;
219 		nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0);
220 		nbp->b_blkno = fsbtodb(fs, nb);
221 		clrbuf(nbp);
222 		/*
223 		 * Write synchronously so that indirect blocks
224 		 * never point at garbage.
225 		 */
226 		if (error = bwrite(nbp)) {
227 			ffs_blkfree(ip, nb, fs->fs_bsize);
228 			brelse(bp);
229 			return (error);
230 		}
231 		bap[indirs[i - 1].in_off] = nb;
232 		/*
233 		 * If required, write synchronously, otherwise use
234 		 * delayed write.
235 		 */
236 		if (flags & B_SYNC) {
237 			bwrite(bp);
238 		} else {
239 			bdwrite(bp);
240 		}
241 	}
242 	/*
243 	 * Get the data block, allocating if necessary.
244 	 */
245 	if (nb == 0) {
246 		pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
247 		if (error = ffs_alloc(ip,
248 		    lbn, pref, (int)fs->fs_bsize, cred, &newb)) {
249 			brelse(bp);
250 			return (error);
251 		}
252 		nb = newb;
253 		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
254 		nbp->b_blkno = fsbtodb(fs, nb);
255 		if (flags & B_CLRBUF)
256 			clrbuf(nbp);
257 		bap[indirs[i].in_off] = nb;
258 		/*
259 		 * If required, write synchronously, otherwise use
260 		 * delayed write.
261 		 */
262 		if (flags & B_SYNC) {
263 			bwrite(bp);
264 		} else {
265 			bdwrite(bp);
266 		}
267 		*bpp = nbp;
268 		return (0);
269 	}
270 	brelse(bp);
271 	if (flags & B_CLRBUF) {
272 		error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
273 		if (error) {
274 			brelse(nbp);
275 			return (error);
276 		}
277 	} else {
278 		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
279 		nbp->b_blkno = fsbtodb(fs, nb);
280 	}
281 	*bpp = nbp;
282 	return (0);
283 }
284