xref: /freebsd/sys/ufs/ffs/ffs_balloc.c (revision a316b26e50bbed7cf655fbba726ab87d8ab7599d)
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  * $Id: ffs_balloc.c,v 1.3 1994/08/02 07:54:18 davidg Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/buf.h>
40 #include <sys/proc.h>
41 #include <sys/file.h>
42 #include <sys/vnode.h>
43 
44 #include <vm/vm.h>
45 
46 #include <ufs/ufs/quota.h>
47 #include <ufs/ufs/inode.h>
48 #include <ufs/ufs/ufs_extern.h>
49 
50 #include <ufs/ffs/fs.h>
51 #include <ufs/ffs/ffs_extern.h>
52 
53 /*
54  * Balloc defines the structure of file system storage
55  * by allocating the physical blocks on a device given
56  * the inode and the logical block number in a file.
57  */
58 int
59 ffs_balloc(ip, bn, size, cred, bpp, flags)
60 	register struct inode *ip;
61 	register daddr_t bn;
62 	int size;
63 	struct ucred *cred;
64 	struct buf **bpp;
65 	int flags;
66 {
67 	register struct fs *fs;
68 	register daddr_t nb;
69 	struct buf *bp, *nbp;
70 	struct vnode *vp = ITOV(ip);
71 	struct indir indirs[NIADDR + 2];
72 	daddr_t newb, lbn, *bap, pref;
73 	int osize, nsize, num, i, error;
74 
75 	*bpp = NULL;
76 	if (bn < 0)
77 		return (EFBIG);
78 	fs = ip->i_fs;
79 	lbn = bn;
80 
81 	/*
82 	 * If the next write will extend the file into a new block,
83 	 * and the file is currently composed of a fragment
84 	 * this fragment has to be extended to be a full block.
85 	 */
86 	nb = lblkno(fs, ip->i_size);
87 	if (nb < NDADDR && nb < bn) {
88 		osize = blksize(fs, ip, nb);
89 		if (osize < fs->fs_bsize && osize > 0) {
90 			error = ffs_realloccg(ip, nb,
91 				ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]),
92 				osize, (int)fs->fs_bsize, cred, &bp);
93 			if (error)
94 				return (error);
95 			ip->i_size = (nb + 1) * fs->fs_bsize;
96 			vnode_pager_setsize(vp, (u_long)ip->i_size);
97 			ip->i_db[nb] = dbtofsb(fs, bp->b_blkno);
98 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
99 			if (flags & B_SYNC)
100 				bwrite(bp);
101 			else
102 				bawrite(bp);
103 		}
104 	}
105 	/*
106 	 * The first NDADDR blocks are direct blocks
107 	 */
108 	if (bn < NDADDR) {
109 		nb = ip->i_db[bn];
110 		if (nb != 0 && ip->i_size >= (bn + 1) * fs->fs_bsize) {
111 			error = bread(vp, bn, fs->fs_bsize, NOCRED, &bp);
112 			if (error) {
113 				brelse(bp);
114 				return (error);
115 			}
116 			*bpp = bp;
117 			return (0);
118 		}
119 		if (nb != 0) {
120 			/*
121 			 * Consider need to reallocate a fragment.
122 			 */
123 			osize = fragroundup(fs, blkoff(fs, ip->i_size));
124 			nsize = fragroundup(fs, size);
125 			if (nsize <= osize) {
126 				error = bread(vp, bn, osize, NOCRED, &bp);
127 				if (error) {
128 					brelse(bp);
129 					return (error);
130 				}
131 			} else {
132 				error = ffs_realloccg(ip, bn,
133 				    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
134 				    osize, nsize, cred, &bp);
135 				if (error)
136 					return (error);
137 			}
138 		} else {
139 			if (ip->i_size < (bn + 1) * fs->fs_bsize)
140 				nsize = fragroundup(fs, size);
141 			else
142 				nsize = fs->fs_bsize;
143 			error = ffs_alloc(ip, bn,
144 			    ffs_blkpref(ip, bn, (int)bn, &ip->i_db[0]),
145 			    nsize, cred, &newb);
146 			if (error)
147 				return (error);
148 			bp = getblk(vp, bn, nsize, 0, 0);
149 			bp->b_blkno = fsbtodb(fs, newb);
150 			if (flags & B_CLRBUF)
151 				clrbuf(bp);
152 		}
153 		ip->i_db[bn] = dbtofsb(fs, bp->b_blkno);
154 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
155 		*bpp = bp;
156 		return (0);
157 	}
158 	/*
159 	 * Determine the number of levels of indirection.
160 	 */
161 	pref = 0;
162 	error = ufs_getlbns(vp, bn, indirs, &num);
163 	if (error)
164 		return(error);
165 #ifdef DIAGNOSTIC
166 	if (num < 1)
167 		panic ("ffs_balloc: ufs_bmaparray returned indirect block\n");
168 #endif
169 	/*
170 	 * Fetch the first indirect block allocating if necessary.
171 	 */
172 	--num;
173 	nb = ip->i_ib[indirs[0].in_off];
174 	if (nb == 0) {
175 		pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
176 	        error = ffs_alloc(ip, lbn, pref,
177 			(int)fs->fs_bsize, cred, &newb);
178 	        if (error)
179 			return (error);
180 		nb = newb;
181 		bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0);
182 		bp->b_blkno = fsbtodb(fs, newb);
183 		clrbuf(bp);
184 		/*
185 		 * Write synchronously so that indirect blocks
186 		 * never point at garbage.
187 		 */
188 		error = bwrite(bp);
189 		if (error) {
190 			ffs_blkfree(ip, nb, fs->fs_bsize);
191 			return (error);
192 		}
193 		ip->i_ib[indirs[0].in_off] = newb;
194 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
195 	}
196 	/*
197 	 * Fetch through the indirect blocks, allocating as necessary.
198 	 */
199 	for (i = 1;;) {
200 		error = bread(vp,
201 		    indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp);
202 		if (error) {
203 			brelse(bp);
204 			return (error);
205 		}
206 		bap = (daddr_t *)bp->b_data;
207 		nb = bap[indirs[i].in_off];
208 		if (i == num)
209 			break;
210 		i += 1;
211 		if (nb != 0) {
212 			brelse(bp);
213 			continue;
214 		}
215 		if (pref == 0)
216 			pref = ffs_blkpref(ip, lbn, 0, (daddr_t *)0);
217 		error =
218 		    ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb);
219 		if (error) {
220 			brelse(bp);
221 			return (error);
222 		}
223 		nb = newb;
224 		nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0);
225 		nbp->b_blkno = fsbtodb(fs, nb);
226 		clrbuf(nbp);
227 		/*
228 		 * Write synchronously so that indirect blocks
229 		 * never point at garbage.
230 		 */
231 		error = bwrite(nbp);
232 		if (error) {
233 			ffs_blkfree(ip, nb, fs->fs_bsize);
234 			brelse(bp);
235 			return (error);
236 		}
237 		bap[indirs[i - 1].in_off] = nb;
238 		/*
239 		 * If required, write synchronously, otherwise use
240 		 * delayed write.
241 		 */
242 		if (flags & B_SYNC) {
243 			bwrite(bp);
244 		} else {
245 			bdwrite(bp);
246 		}
247 	}
248 	/*
249 	 * Get the data block, allocating if necessary.
250 	 */
251 	if (nb == 0) {
252 		pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
253 		error = ffs_alloc(ip,
254 		    lbn, pref, (int)fs->fs_bsize, cred, &newb);
255 		if (error) {
256 			brelse(bp);
257 			return (error);
258 		}
259 		nb = newb;
260 		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
261 		nbp->b_blkno = fsbtodb(fs, nb);
262 		if (flags & B_CLRBUF)
263 			clrbuf(nbp);
264 		bap[indirs[i].in_off] = nb;
265 		/*
266 		 * If required, write synchronously, otherwise use
267 		 * delayed write.
268 		 */
269 		if (flags & B_SYNC) {
270 			bwrite(bp);
271 		} else {
272 			bdwrite(bp);
273 		}
274 		*bpp = nbp;
275 		return (0);
276 	}
277 	brelse(bp);
278 	if (flags & B_CLRBUF) {
279 		error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp);
280 		if (error) {
281 			brelse(nbp);
282 			return (error);
283 		}
284 	} else {
285 		nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0);
286 		nbp->b_blkno = fsbtodb(fs, nb);
287 	}
288 	*bpp = nbp;
289 	return (0);
290 }
291