Change the kernel dev_t, representing a pointer to a specinfo structure,
[dragonfly.git] / sys / vfs / ufs / ffs_subr.c
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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_subr.c 8.5 (Berkeley) 3/21/95
34 * $FreeBSD: src/sys/ufs/ffs/ffs_subr.c,v 1.25 1999/12/29 04:55:04 peter Exp $
9ba4b517 35 * $DragonFly: src/sys/vfs/ufs/ffs_subr.c,v 1.13 2006/05/26 19:57:33 dillon Exp $
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36 */
37
38#include <sys/param.h>
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39
40#ifndef _KERNEL
1f2de5d4 41#include "dinode.h"
50e58362 42#include "fs.h"
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43#else
44#include "opt_ddb.h"
45
46#include <sys/systm.h>
47#include <sys/lock.h>
48#include <sys/vnode.h>
49#include <sys/buf.h>
50#include <sys/ucred.h>
9ba4b517 51#include <sys/mount.h>
984263bc 52
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53#include "quota.h"
54#include "inode.h"
50e58362 55#include "fs.h"
1f2de5d4 56#include "ffs_extern.h"
984263bc 57
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58/*
59 * Return buffer with the contents of block "offset" from the beginning of
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60 * vnode "vp". If "res" is non-zero, fill it in with a pointer to the
61 * remaining space in the vnode.
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62 */
63int
9ba4b517 64ffs_blkatoff(struct vnode *vp, off_t uoffset, char **res, struct buf **bpp)
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65{
66 struct inode *ip;
3ff2135f 67 struct fs *fs;
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68 struct buf *bp;
69 ufs_daddr_t lbn;
70 int bsize, error;
71
72 ip = VTOI(vp);
73 fs = ip->i_fs;
9ba4b517 74 lbn = lblkno(fs, uoffset);
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75 bsize = blksize(fs, ip, lbn);
76
77 *bpp = NULL;
54078292 78 error = bread(vp, lblktodoff(fs, lbn), bsize, &bp);
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79 if (error) {
80 brelse(bp);
81 return (error);
82 }
83 if (res)
9ba4b517 84 *res = (char *)bp->b_data + blkoff(fs, uoffset);
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85 *bpp = bp;
86 return (0);
87}
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88
89/*
90 * Return buffer with the contents of block "offset" from the beginning of
91 * vnode "vp". If "res" is non-zero, fill it in with a pointer to the
92 * remaining space in the vnode.
93 *
94 * This version includes a read-ahead optimization.
95 */
96int
97ffs_blkatoff_ra(struct vnode *vp, off_t uoffset, char **res, struct buf **bpp,
98 int seqcount)
99{
100 struct inode *ip;
101 struct fs *fs;
102 struct buf *bp;
103 ufs_daddr_t lbn;
104 ufs_daddr_t nextlbn;
105 off_t base_loffset;
106 off_t next_loffset;
107 int bsize, error;
108 int nextbsize;
109
110 ip = VTOI(vp);
111 fs = ip->i_fs;
112 lbn = lblkno(fs, uoffset);
113 base_loffset = lblktodoff(fs, lbn);
114 bsize = blksize(fs, ip, lbn);
115
116 nextlbn = lbn + 1;
117 next_loffset = lblktodoff(fs, nextlbn);
118
119
120 *bpp = NULL;
121
122 if (next_loffset >= ip->i_size) {
123 /*
124 * Do not do readahead if this is the last block
125 */
126 error = bread(vp, base_loffset, bsize, &bp);
127 } else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
128 /*
129 * Try to cluster if we allowed to.
130 */
131 error = cluster_read(vp, (off_t)ip->i_size,
132 base_loffset, bsize,
133 MAXBSIZE, seqcount, &bp);
134 } else if (seqcount > 1) {
135 /*
136 * Faked read ahead
137 */
138 nextbsize = blksize(fs, ip, nextlbn);
139 error = breadn(vp, base_loffset, bsize,
140 &next_loffset, &nextbsize, 1, &bp);
141 } else {
142 /*
143 * Failing all of the above, just read what the
144 * user asked for. Interestingly, the same as
145 * the first option above.
146 */
147 error = bread(vp, base_loffset, bsize, &bp);
148 }
149 if (error) {
150 brelse(bp);
151 return (error);
152 }
153 if (res)
154 *res = (char *)bp->b_data + (int)(uoffset - base_loffset);
155 *bpp = bp;
156 return (0);
157}
158
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159#endif
160
161/*
162 * Update the frsum fields to reflect addition or deletion
163 * of some frags.
164 */
165void
0973c589 166ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt)
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167{
168 int inblk;
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169 int field, subfield;
170 int siz, pos;
984263bc 171
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172 /*
173 * inblk represents a bitmap of fragment sizes which may be
174 * contained in the data 'fragmap'. e.g. if a fragment of size
175 * 1 is available, bit 0 would be set. inblk is shifted left
176 * by one so we do not have to calculate (1 << (siz - 1)).
177 *
178 * fragment represents the data pattern we are trying to decipher,
179 * we shift it left by one to align it with the 'around' and 'inside'
180 * masks.
181 *
182 * around represents the bits around the subfield and is a mask.
183 * inside represents what we must match within the mask, it is
184 * basically the mask with the first and last bit set to 0, allowing
185 * us to represent a whole fragment.
186 *
187 * When we find a match we bump our position by the size of the
188 * matching fragment, then bump the position again:
189 *
190 * 010101010 fragmap (shifted left by 1)
191 * 111 around mask
192 * 010 inside mask
193 * 111 (shifted by siz)
194 * 010
195 * 111 (shifted again)
196 * 010
197 */
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198 inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
199 fragmap <<= 1;
200 for (siz = 1; siz < fs->fs_frag; siz++) {
201 if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
202 continue;
203 field = around[siz];
204 subfield = inside[siz];
205 for (pos = siz; pos <= fs->fs_frag; pos++) {
206 if ((fragmap & field) == subfield) {
207 fraglist[siz] += cnt;
208 pos += siz;
209 field <<= siz;
210 subfield <<= siz;
211 }
212 field <<= 1;
213 subfield <<= 1;
214 }
215 }
216}
217
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218/*
219 * block operations
220 *
221 * check if a block is available
222 */
223int
0973c589 224ffs_isblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h)
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225{
226 unsigned char mask;
227
228 switch ((int)fs->fs_frag) {
229 case 8:
230 return (cp[h] == 0xff);
231 case 4:
232 mask = 0x0f << ((h & 0x1) << 2);
233 return ((cp[h >> 1] & mask) == mask);
234 case 2:
235 mask = 0x03 << ((h & 0x3) << 1);
236 return ((cp[h >> 2] & mask) == mask);
237 case 1:
238 mask = 0x01 << (h & 0x7);
239 return ((cp[h >> 3] & mask) == mask);
240 default:
241 panic("ffs_isblock");
242 }
243}
244
245/*
246 * check if a block is free
247 */
248int
0973c589 249ffs_isfreeblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h)
984263bc 250{
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251 switch ((int)fs->fs_frag) {
252 case 8:
253 return (cp[h] == 0);
254 case 4:
255 return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
256 case 2:
257 return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
258 case 1:
259 return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
260 default:
261 panic("ffs_isfreeblock");
262 }
263}
264
265/*
266 * take a block out of the map
267 */
268void
0973c589 269ffs_clrblock(struct fs *fs, u_char *cp, ufs_daddr_t h)
984263bc 270{
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271 switch ((int)fs->fs_frag) {
272 case 8:
273 cp[h] = 0;
274 return;
275 case 4:
276 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
277 return;
278 case 2:
279 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
280 return;
281 case 1:
282 cp[h >> 3] &= ~(0x01 << (h & 0x7));
283 return;
284 default:
285 panic("ffs_clrblock");
286 }
287}
288
289/*
290 * put a block into the map
291 */
292void
0973c589 293ffs_setblock(struct fs *fs, unsigned char *cp, ufs_daddr_t h)
984263bc 294{
984263bc 295 switch ((int)fs->fs_frag) {
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296 case 8:
297 cp[h] = 0xff;
298 return;
299 case 4:
300 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
301 return;
302 case 2:
303 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
304 return;
305 case 1:
306 cp[h >> 3] |= (0x01 << (h & 0x7));
307 return;
308 default:
309 panic("ffs_setblock");
310 }
311}