Line data Source code
1 : /* $OpenBSD: ext2fs_balloc.c,v 1.26 2016/06/03 18:00:10 natano Exp $ */
2 : /* $NetBSD: ext2fs_balloc.c,v 1.10 2001/07/04 21:16:01 chs Exp $ */
3 :
4 : /*
5 : * Copyright (c) 1997 Manuel Bouyer.
6 : * Copyright (c) 1982, 1986, 1989, 1993
7 : * The Regents of the University of California. All rights reserved.
8 : *
9 : * Redistribution and use in source and binary forms, with or without
10 : * modification, are permitted provided that the following conditions
11 : * are met:
12 : * 1. Redistributions of source code must retain the above copyright
13 : * notice, this list of conditions and the following disclaimer.
14 : * 2. Redistributions in binary form must reproduce the above copyright
15 : * notice, this list of conditions and the following disclaimer in the
16 : * documentation and/or other materials provided with the distribution.
17 : * 3. 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 : * Modified for ext2fs by Manuel Bouyer.
35 : */
36 :
37 : #include <sys/param.h>
38 : #include <sys/systm.h>
39 : #include <sys/buf.h>
40 : #include <sys/vnode.h>
41 :
42 : #include <ufs/ufs/quota.h>
43 : #include <ufs/ufs/inode.h>
44 : #include <ufs/ufs/ufs_extern.h>
45 :
46 : #include <ufs/ext2fs/ext2fs.h>
47 : #include <ufs/ext2fs/ext2fs_extern.h>
48 :
49 : /*
50 : * Balloc defines the structure of file system storage
51 : * by allocating the physical blocks on a device given
52 : * the inode and the logical block number in a file.
53 : */
54 : int
55 0 : ext2fs_buf_alloc(struct inode *ip, u_int32_t bn, int size, struct ucred *cred,
56 : struct buf **bpp, int flags)
57 : {
58 : struct m_ext2fs *fs;
59 0 : struct buf *bp, *nbp;
60 0 : struct vnode *vp = ITOV(ip);
61 0 : struct indir indirs[NIADDR + 2];
62 0 : u_int32_t nb, newb, *bap;
63 0 : int num, i, error;
64 : u_int deallocated;
65 0 : u_int32_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1];
66 : int unwindidx = -1;
67 : daddr_t lbn, pref;
68 :
69 0 : *bpp = NULL;
70 0 : fs = ip->i_e2fs;
71 0 : lbn = bn;
72 :
73 : /*
74 : * The first NDADDR blocks are direct blocks
75 : */
76 0 : if (bn < NDADDR) {
77 0 : nb = letoh32(ip->i_e2fs_blocks[bn]);
78 0 : if (nb != 0) {
79 0 : error = bread(vp, bn, fs->e2fs_bsize, &bp);
80 0 : if (error) {
81 0 : brelse(bp);
82 0 : return (error);
83 : }
84 0 : *bpp = bp;
85 0 : return (0);
86 : }
87 :
88 : /*
89 : * allocate a new direct block.
90 : */
91 0 : error = ext2fs_alloc(ip, bn,
92 0 : ext2fs_blkpref(ip, bn, (int)bn, &ip->i_e2fs_blocks[0]),
93 : cred, &newb);
94 0 : if (error)
95 0 : return (error);
96 0 : ip->i_e2fs_last_lblk = lbn;
97 0 : ip->i_e2fs_last_blk = newb;
98 0 : ip->i_e2fs_blocks[bn] = htole32(newb);
99 0 : ip->i_flag |= IN_CHANGE | IN_UPDATE;
100 0 : bp = getblk(vp, bn, fs->e2fs_bsize, 0, 0);
101 0 : bp->b_blkno = fsbtodb(fs, newb);
102 0 : if (flags & B_CLRBUF)
103 0 : clrbuf(bp);
104 0 : *bpp = bp;
105 0 : return (0);
106 : }
107 : /*
108 : * Determine the number of levels of indirection.
109 : */
110 : pref = 0;
111 0 : if ((error = ufs_getlbns(vp, bn, indirs, &num)) != 0)
112 0 : return(error);
113 : #ifdef DIAGNOSTIC
114 0 : if (num < 1)
115 0 : panic ("ext2fs_balloc: ufs_getlbns returned indirect block");
116 : #endif
117 : /*
118 : * Fetch the first indirect block allocating if necessary.
119 : */
120 0 : --num;
121 0 : nb = letoh32(ip->i_e2fs_blocks[NDADDR + indirs[0].in_off]);
122 : allocib = NULL;
123 0 : allocblk = allociblk;
124 0 : if (nb == 0) {
125 0 : pref = ext2fs_blkpref(ip, lbn, 0, NULL);
126 0 : error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
127 0 : if (error)
128 0 : return (error);
129 0 : nb = newb;
130 0 : *allocblk++ = nb;
131 0 : ip->i_e2fs_last_blk = newb;
132 0 : bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0);
133 0 : bp->b_blkno = fsbtodb(fs, newb);
134 0 : clrbuf(bp);
135 : /*
136 : * Write synchronously so that indirect blocks
137 : * never point at garbage.
138 : */
139 0 : if ((error = bwrite(bp)) != 0)
140 : goto fail;
141 : unwindidx = 0;
142 0 : allocib = &ip->i_e2fs_blocks[NDADDR + indirs[0].in_off];
143 0 : *allocib = htole32(newb);
144 0 : ip->i_flag |= IN_CHANGE | IN_UPDATE;
145 0 : }
146 : /*
147 : * Fetch through the indirect blocks, allocating as necessary.
148 : */
149 0 : for (i = 1;;) {
150 0 : error = bread(vp, indirs[i].in_lbn, (int)fs->e2fs_bsize, &bp);
151 0 : if (error) {
152 0 : brelse(bp);
153 0 : goto fail;
154 : }
155 0 : bap = (u_int32_t *)bp->b_data;
156 0 : nb = letoh32(bap[indirs[i].in_off]);
157 0 : if (i == num)
158 : break;
159 0 : i++;
160 0 : if (nb != 0) {
161 0 : brelse(bp);
162 0 : continue;
163 : }
164 0 : pref = ext2fs_blkpref(ip, lbn, 0, NULL);
165 0 : error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
166 0 : if (error) {
167 0 : brelse(bp);
168 0 : goto fail;
169 : }
170 0 : nb = newb;
171 0 : *allocblk++ = nb;
172 0 : ip->i_e2fs_last_blk = newb;
173 0 : nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0);
174 0 : nbp->b_blkno = fsbtodb(fs, nb);
175 0 : clrbuf(nbp);
176 : /*
177 : * Write synchronously so that indirect blocks
178 : * never point at garbage.
179 : */
180 0 : if ((error = bwrite(nbp)) != 0) {
181 0 : brelse(bp);
182 0 : goto fail;
183 : }
184 0 : if (unwindidx < 0)
185 0 : unwindidx = i - 1;
186 0 : bap[indirs[i - 1].in_off] = htole32(nb);
187 : /*
188 : * If required, write synchronously, otherwise use
189 : * delayed write.
190 : */
191 0 : if (flags & B_SYNC) {
192 0 : bwrite(bp);
193 0 : } else {
194 0 : bdwrite(bp);
195 : }
196 : }
197 : /*
198 : * Get the data block, allocating if necessary.
199 : */
200 0 : if (nb == 0) {
201 0 : pref = ext2fs_blkpref(ip, lbn, indirs[num].in_off, bap);
202 0 : error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
203 0 : if (error) {
204 0 : brelse(bp);
205 0 : goto fail;
206 : }
207 0 : nb = newb;
208 0 : *allocblk++ = nb;
209 0 : ip->i_e2fs_last_lblk = lbn;
210 0 : ip->i_e2fs_last_blk = newb;
211 0 : bap[indirs[num].in_off] = htole32(nb);
212 : /*
213 : * If required, write synchronously, otherwise use
214 : * delayed write.
215 : */
216 0 : if (flags & B_SYNC) {
217 0 : bwrite(bp);
218 0 : } else {
219 0 : bdwrite(bp);
220 : }
221 0 : nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0);
222 0 : nbp->b_blkno = fsbtodb(fs, nb);
223 0 : if (flags & B_CLRBUF)
224 0 : clrbuf(nbp);
225 0 : *bpp = nbp;
226 0 : return (0);
227 : }
228 0 : brelse(bp);
229 0 : if (flags & B_CLRBUF) {
230 0 : error = bread(vp, lbn, (int)fs->e2fs_bsize, &nbp);
231 0 : if (error) {
232 0 : brelse(nbp);
233 0 : goto fail;
234 : }
235 : } else {
236 0 : nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0);
237 0 : nbp->b_blkno = fsbtodb(fs, nb);
238 : }
239 :
240 0 : *bpp = nbp;
241 0 : return (0);
242 : fail:
243 : /*
244 : * If we have failed part way through block allocation, we
245 : * have to deallocate any indirect blocks that we have allocated.
246 : */
247 0 : for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) {
248 0 : ext2fs_blkfree(ip, *blkp);
249 0 : deallocated += fs->e2fs_bsize;
250 : }
251 0 : if (unwindidx >= 0) {
252 0 : if (unwindidx == 0) {
253 0 : *allocib = 0;
254 0 : } else {
255 : int r;
256 :
257 0 : r = bread(vp, indirs[unwindidx].in_lbn,
258 0 : (int)fs->e2fs_bsize, &bp);
259 0 : if (r) {
260 0 : panic("Could not unwind indirect block, error %d", r);
261 : } else {
262 0 : bap = (u_int32_t *)bp->b_data;
263 0 : bap[indirs[unwindidx].in_off] = 0;
264 0 : if (flags & B_SYNC)
265 0 : bwrite(bp);
266 : else
267 0 : bdwrite(bp);
268 : }
269 : }
270 0 : for (i = unwindidx + 1; i <= num; i++) {
271 0 : bp = getblk(vp, indirs[i].in_lbn, (int)fs->e2fs_bsize,
272 : 0, 0);
273 0 : bp->b_flags |= B_INVAL;
274 0 : brelse(bp);
275 : }
276 : }
277 0 : if (deallocated) {
278 0 : ip->i_e2fs_nblock -= btodb(deallocated);
279 0 : ip->i_e2fs_flags |= IN_CHANGE | IN_UPDATE;
280 0 : }
281 0 : return error;
282 0 : }
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