xref: /netbsd-src/sys/ufs/ext2fs/ext2fs_balloc.c (revision fdecd6a253f999ae92b139670d9e15cc9df4497c)
1 /*	$NetBSD: ext2fs_balloc.c,v 1.1 1997/06/11 09:33:44 bouyer Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 Manuel Bouyer.
5  * Copyright (c) 1982, 1986, 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)ffs_balloc.c	8.4 (Berkeley) 9/23/93
37  * Modified for ext2fs by Manuel Bouyer.
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/buf.h>
43 #include <sys/proc.h>
44 #include <sys/file.h>
45 #include <sys/vnode.h>
46 
47 #include <vm/vm.h>
48 
49 #include <ufs/ufs/quota.h>
50 #include <ufs/ufs/inode.h>
51 #include <ufs/ufs/ufs_extern.h>
52 
53 #include <ufs/ext2fs/ext2fs.h>
54 #include <ufs/ext2fs/ext2fs_extern.h>
55 
56 /*
57  * Balloc defines the structure of file system storage
58  * by allocating the physical blocks on a device given
59  * the inode and the logical block number in a file.
60  */
61 int
62 ext2fs_balloc(ip, bn, size, cred, bpp, flags)
63 	register struct inode *ip;
64 	register daddr_t bn;
65 	int size;
66 	struct ucred *cred;
67 	struct buf **bpp;
68 	int flags;
69 {
70 	register struct m_ext2fs *fs;
71 	register daddr_t nb;
72 	struct buf *bp, *nbp;
73 	struct vnode *vp = ITOV(ip);
74 	struct indir indirs[NIADDR + 2];
75 	daddr_t newb, lbn, *bap, pref;
76 	int num, i, error;
77 
78 	*bpp = NULL;
79 	if (bn < 0)
80 		return (EFBIG);
81 	fs = ip->i_e2fs;
82 	lbn = bn;
83 
84 	/*
85 	 * The first NDADDR blocks are direct blocks
86 	 */
87 	if (bn < NDADDR) {
88 		nb = ip->i_e2fs_blocks[bn];
89 		if (nb != 0) {
90 			error = bread(vp, bn, fs->e2fs_bsize, NOCRED, &bp);
91 			if (error) {
92 				brelse(bp);
93 				return (error);
94 			}
95 			*bpp = bp;
96 			return (0);
97 		} else {
98 			error = ext2fs_alloc(ip, bn,
99 				ext2fs_blkpref(ip, bn, (int)bn, &ip->i_e2fs_blocks[0]),
100 				cred, &newb);
101 			if (error)
102 				return (error);
103 			ip->i_e2fs_last_lblk = lbn;
104 			ip->i_e2fs_last_blk = newb;
105 			bp = getblk(vp, bn, fs->e2fs_bsize, 0, 0);
106 			bp->b_blkno = fsbtodb(fs, newb);
107 			if (flags & B_CLRBUF)
108 				clrbuf(bp);
109 		}
110 		ip->i_e2fs_blocks[bn] = dbtofsb(fs, bp->b_blkno);
111 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
112 		*bpp = bp;
113 		return (0);
114 	}
115 	/*
116 	 * Determine the number of levels of indirection.
117 	 */
118 	pref = 0;
119 	if ((error = ufs_getlbns(vp, bn, indirs, &num)) != 0)
120 		return(error);
121 #ifdef DIAGNOSTIC
122 	if (num < 1)
123 		panic ("ext2fs_balloc: ufs_getlbns returned indirect block\n");
124 #endif
125 	/*
126 	 * Fetch the first indirect block allocating if necessary.
127 	 */
128 	--num;
129 	nb = ip->i_e2fs_blocks[NDADDR + indirs[0].in_off];
130 	if (nb == 0) {
131 		pref = ext2fs_blkpref(ip, lbn, 0, (daddr_t *)0);
132 			error = ext2fs_alloc(ip, lbn, pref,
133 				  cred, &newb);
134 		if (error)
135 			return (error);
136 		nb = newb;
137 		ip->i_e2fs_last_blk = newb;
138 		bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0);
139 		bp->b_blkno = fsbtodb(fs, newb);
140 		clrbuf(bp);
141 		/*
142 		 * Write synchronously so that indirect blocks
143 		 * never point at garbage.
144 		 */
145 		if ((error = bwrite(bp)) != 0) {
146 			ext2fs_blkfree(ip, nb);
147 			return (error);
148 		}
149 		ip->i_e2fs_blocks[NDADDR + indirs[0].in_off] = newb;
150 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
151 	}
152 	/*
153 	 * Fetch through the indirect blocks, allocating as necessary.
154 	 */
155 	for (i = 1;;) {
156 		error = bread(vp,
157 			indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
158 		if (error) {
159 			brelse(bp);
160 			return (error);
161 		}
162 		bap = (daddr_t *)bp->b_data;
163 		nb = bap[indirs[i].in_off];
164 		if (i == num)
165 			break;
166 		i += 1;
167 		if (nb != 0) {
168 			brelse(bp);
169 			continue;
170 		}
171 		pref = ext2fs_blkpref(ip, lbn, 0, (daddr_t *)0);
172 		error = ext2fs_alloc(ip, lbn, pref, cred,
173 				  &newb);
174 		if (error) {
175 			brelse(bp);
176 			return (error);
177 		}
178 		nb = newb;
179 		ip->i_e2fs_last_blk = newb;
180 		nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0);
181 		nbp->b_blkno = fsbtodb(fs, nb);
182 		clrbuf(nbp);
183 		/*
184 		 * Write synchronously so that indirect blocks
185 		 * never point at garbage.
186 		 */
187 		if ((error = bwrite(nbp)) != 0) {
188 			ext2fs_blkfree(ip, nb);
189 			brelse(bp);
190 			return (error);
191 		}
192 		bap[indirs[i - 1].in_off] = nb;
193 		/*
194 		 * If required, write synchronously, otherwise use
195 		 * delayed write.
196 		 */
197 		if (flags & B_SYNC) {
198 			bwrite(bp);
199 		} else {
200 			bdwrite(bp);
201 		}
202 	}
203 	/*
204 	 * Get the data block, allocating if necessary.
205 	 */
206 	if (nb == 0) {
207 		pref = ext2fs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]);
208 		error = ext2fs_alloc(ip, lbn, pref, cred,
209 				  &newb);
210 		if (error) {
211 			brelse(bp);
212 			return (error);
213 		}
214 		nb = newb;
215 		ip->i_e2fs_last_lblk = lbn;
216 		ip->i_e2fs_last_blk = newb;
217 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0);
218 		nbp->b_blkno = fsbtodb(fs, nb);
219 		if (flags & B_CLRBUF)
220 			clrbuf(nbp);
221 		bap[indirs[i].in_off] = nb;
222 		/*
223 		 * If required, write synchronously, otherwise use
224 		 * delayed write.
225 		 */
226 		if (flags & B_SYNC) {
227 			bwrite(bp);
228 		} else {
229 			bdwrite(bp);
230 		}
231 		*bpp = nbp;
232 		return (0);
233 	}
234 	brelse(bp);
235 	if (flags & B_CLRBUF) {
236 		error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
237 		if (error) {
238 			brelse(nbp);
239 			return (error);
240 		}
241 	} else {
242 		nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0);
243 		nbp->b_blkno = fsbtodb(fs, nb);
244 	}
245 	*bpp = nbp;
246 	return (0);
247 }
248