1 /*-
2 * modified for Lites 1.1
3 *
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
6 */
7 /*-
8 * Copyright (c) 1982, 1986, 1989, 1993
9 * The Regents of the University of California. All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)ffs_balloc.c 8.4 (Berkeley) 9/23/93
36 * $FreeBSD: releng/10.4/sys/fs/ext2fs/ext2_balloc.c 311232 2017-01-04 02:43:33Z pfg $
37 */
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/bio.h>
42 #include <sys/buf.h>
43 #include <sys/lock.h>
44 #include <sys/mount.h>
45 #include <sys/vnode.h>
46
47 #include <fs/ext2fs/fs.h>
48 #include <fs/ext2fs/inode.h>
49 #include <fs/ext2fs/ext2fs.h>
50 #include <fs/ext2fs/ext2_dinode.h>
51 #include <fs/ext2fs/ext2_extern.h>
52 #include <fs/ext2fs/ext2_mount.h>
53
54 /*
55 * Balloc defines the structure of filesystem storage
56 * by allocating the physical blocks on a device given
57 * the inode and the logical block number in a file.
58 */
59 int
60 ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size, struct ucred *cred,
61 struct buf **bpp, int flags)
62 {
63 struct m_ext2fs *fs;
64 struct ext2mount *ump;
65 struct buf *bp, *nbp;
66 struct vnode *vp = ITOV(ip);
67 struct indir indirs[NIADDR + 2];
68 e4fs_daddr_t nb, newb;
69 e2fs_daddr_t *bap, pref;
70 int osize, nsize, num, i, error;
71
72 *bpp = NULL;
73 if (lbn < 0)
74 return (EFBIG);
75 fs = ip->i_e2fs;
76 ump = ip->i_ump;
77
78 /*
79 * check if this is a sequential block allocation.
80 * If so, increment next_alloc fields to allow ext2_blkpref
81 * to make a good guess
82 */
83 if (lbn == ip->i_next_alloc_block + 1) {
84 ip->i_next_alloc_block++;
85 ip->i_next_alloc_goal++;
86 }
87 /*
88 * The first NDADDR blocks are direct blocks
89 */
90 if (lbn < NDADDR) {
91 nb = ip->i_db[lbn];
92 /*
93 * no new block is to be allocated, and no need to expand
94 * the file
95 */
96 if (nb != 0 && ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
97 error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
98 if (error) {
99 brelse(bp);
100 return (error);
101 }
102 bp->b_blkno = fsbtodb(fs, nb);
103 *bpp = bp;
104 return (0);
105 }
106 if (nb != 0) {
107 /*
108 * Consider need to reallocate a fragment.
109 */
110 osize = fragroundup(fs, blkoff(fs, ip->i_size));
111 nsize = fragroundup(fs, size);
112 if (nsize <= osize) {
113 error = bread(vp, lbn, osize, NOCRED, &bp);
114 if (error) {
115 brelse(bp);
116 return (error);
117 }
118 bp->b_blkno = fsbtodb(fs, nb);
119 } else {
120 /*
121 * Godmar thinks: this shouldn't happen w/o
122 * fragments
123 */
124 printf("nsize %d(%d) > osize %d(%d) nb %d\n",
125 (int)nsize, (int)size, (int)osize,
126 (int)ip->i_size, (int)nb);
127 panic(
128 "ext2_balloc: Something is terribly wrong");
129 /*
130 * please note there haven't been any changes from here on -
131 * FFS seems to work.
132 */
133 }
134 } else {
135 if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
136 nsize = fragroundup(fs, size);
137 else
138 nsize = fs->e2fs_bsize;
139 EXT2_LOCK(ump);
140 error = ext2_alloc(ip, lbn,
141 ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
142 nsize, cred, &newb);
143 if (error)
144 return (error);
145 bp = getblk(vp, lbn, nsize, 0, 0, 0);
146 bp->b_blkno = fsbtodb(fs, newb);
147 if (flags & BA_CLRBUF)
148 vfs_bio_clrbuf(bp);
149 }
150 ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
151 ip->i_flag |= IN_CHANGE | IN_UPDATE;
152 *bpp = bp;
153 return (0);
154 }
155 /*
156 * Determine the number of levels of indirection.
157 */
158 pref = 0;
159 if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
160 return (error);
161 #ifdef INVARIANTS
162 if (num < 1)
163 panic("ext2_balloc: ext2_getlbns returned indirect block");
164 #endif
165 /*
166 * Fetch the first indirect block allocating if necessary.
167 */
168 --num;
169 nb = ip->i_ib[indirs[0].in_off];
170 if (nb == 0) {
171 EXT2_LOCK(ump);
172 pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
173 EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
174 if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred,
175 &newb)))
176 return (error);
177 nb = newb;
178 bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
179 bp->b_blkno = fsbtodb(fs, newb);
180 vfs_bio_clrbuf(bp);
181 /*
182 * Write synchronously so that indirect blocks
183 * never point at garbage.
184 */
185 if ((error = bwrite(bp)) != 0) {
186 ext2_blkfree(ip, nb, fs->e2fs_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->e2fs_bsize, NOCRED, &bp);
198 if (error) {
199 brelse(bp);
200 return (error);
201 }
202 bap = (e2fs_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 bqrelse(bp);
209 continue;
210 }
211 EXT2_LOCK(ump);
212 if (pref == 0)
213 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
214 bp->b_lblkno);
215 error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
216 if (error) {
217 brelse(bp);
218 return (error);
219 }
220 nb = newb;
221 nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
222 nbp->b_blkno = fsbtodb(fs, nb);
223 vfs_bio_clrbuf(nbp);
224 /*
225 * Write synchronously so that indirect blocks
226 * never point at garbage.
227 */
228 if ((error = bwrite(nbp)) != 0) {
229 ext2_blkfree(ip, nb, fs->e2fs_bsize);
230 EXT2_UNLOCK(ump);
231 brelse(bp);
232 return (error);
233 }
234 bap[indirs[i - 1].in_off] = nb;
235 /*
236 * If required, write synchronously, otherwise use
237 * delayed write.
238 */
239 if (flags & IO_SYNC) {
240 bwrite(bp);
241 } else {
242 if (bp->b_bufsize == fs->e2fs_bsize)
243 bp->b_flags |= B_CLUSTEROK;
244 bdwrite(bp);
245 }
246 }
247 /*
248 * Get the data block, allocating if necessary.
249 */
250 if (nb == 0) {
251 EXT2_LOCK(ump);
252 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
253 bp->b_lblkno);
254 if ((error = ext2_alloc(ip,
255 lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
256 brelse(bp);
257 return (error);
258 }
259 nb = newb;
260 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
261 nbp->b_blkno = fsbtodb(fs, nb);
262 if (flags & BA_CLRBUF)
263 vfs_bio_clrbuf(nbp);
264 bap[indirs[i].in_off] = nb;
265 /*
266 * If required, write synchronously, otherwise use
267 * delayed write.
268 */
269 if (flags & IO_SYNC) {
270 bwrite(bp);
271 } else {
272 if (bp->b_bufsize == fs->e2fs_bsize)
273 bp->b_flags |= B_CLUSTEROK;
274 bdwrite(bp);
275 }
276 *bpp = nbp;
277 return (0);
278 }
279 brelse(bp);
280 if (flags & BA_CLRBUF) {
281 int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
282
283 if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
284 error = cluster_read(vp, ip->i_size, lbn,
285 (int)fs->e2fs_bsize, NOCRED,
286 MAXBSIZE, seqcount, 0, &nbp);
287 } else {
288 error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
289 }
290 if (error) {
291 brelse(nbp);
292 return (error);
293 }
294 } else {
295 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
296 nbp->b_blkno = fsbtodb(fs, nb);
297 }
298 *bpp = nbp;
299 return (0);
300 }
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