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_subr.c 8.2 (Berkeley) 9/21/93
36 * $FreeBSD: releng/9.1/sys/fs/ext2fs/ext2_subr.c 229549 2012-01-05 01:35:01Z pfg $
37 */
38
39 #include <sys/param.h>
40
41 #include <sys/proc.h>
42 #include <sys/systm.h>
43 #include <sys/bio.h>
44 #include <sys/buf.h>
45 #include <sys/lock.h>
46 #include <sys/ucred.h>
47 #include <sys/vnode.h>
48
49 #include <fs/ext2fs/inode.h>
50 #include <fs/ext2fs/ext2_extern.h>
51 #include <fs/ext2fs/ext2fs.h>
52 #include <fs/ext2fs/fs.h>
53
54 #ifdef KDB
55 #include <fs/ext2fs/ext2_mount.h>
56
57 void ext2_checkoverlap(struct buf *, struct inode *);
58 #endif
59
60 /*
61 * Return buffer with the contents of block "offset" from the beginning of
62 * directory "ip". If "res" is non-zero, fill it in with a pointer to the
63 * remaining space in the directory.
64 */
65 int
66 ext2_blkatoff(vp, offset, res, bpp)
67 struct vnode *vp;
68 off_t offset;
69 char **res;
70 struct buf **bpp;
71 {
72 struct inode *ip;
73 struct m_ext2fs *fs;
74 struct buf *bp;
75 int32_t lbn;
76 int bsize, error;
77
78 ip = VTOI(vp);
79 fs = ip->i_e2fs;
80 lbn = lblkno(fs, offset);
81 bsize = blksize(fs, ip, lbn);
82
83 *bpp = NULL;
84 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) {
85 brelse(bp);
86 return (error);
87 }
88 if (res)
89 *res = (char *)bp->b_data + blkoff(fs, offset);
90 *bpp = bp;
91 return (0);
92 }
93
94 #ifdef KDB
95 void
96 ext2_checkoverlap(bp, ip)
97 struct buf *bp;
98 struct inode *ip;
99 {
100 struct buf *ebp, *ep;
101 int32_t start, last;
102 struct vnode *vp;
103
104 ebp = &buf[nbuf];
105 start = bp->b_blkno;
106 last = start + btodb(bp->b_bcount) - 1;
107 for (ep = buf; ep < ebp; ep++) {
108 if (ep == bp || (ep->b_flags & B_INVAL))
109 continue;
110 vp = ip->i_ump->um_devvp;
111 /* look for overlap */
112 if (ep->b_bcount == 0 || ep->b_blkno > last ||
113 ep->b_blkno + btodb(ep->b_bcount) <= start)
114 continue;
115 vprint("Disk overlap", vp);
116 (void)printf("\tstart %d, end %d overlap start %lld, end %ld\n",
117 start, last, (long long)ep->b_blkno,
118 (long)(ep->b_blkno + btodb(ep->b_bcount) - 1));
119 panic("Disk buffer overlap");
120 }
121 }
122 #endif /* KDB */
123
124 /*
125 * Update the cluster map because of an allocation of free like ffs.
126 *
127 * Cnt == 1 means free; cnt == -1 means allocating.
128 */
129 void
130 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, daddr_t bno, int cnt)
131 {
132 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum;
133 int32_t *lp;
134 int back, bit, end, forw, i, loc, start;
135
136 /* Initialize the cluster summary array. */
137 if (fs->e2fs_clustersum[cg].cs_init == 0) {
138 int run = 0;
139 bit = 1;
140 loc = 0;
141
142 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) {
143 if ((bbp[loc] & bit) == 0)
144 run++;
145 else if (run != 0) {
146 if (run > fs->e2fs_contigsumsize)
147 run = fs->e2fs_contigsumsize;
148 sump[run]++;
149 run = 0;
150 }
151 if ((i & (NBBY - 1)) != (NBBY - 1))
152 bit <<= 1;
153 else {
154 loc++;
155 bit = 1;
156 }
157 }
158 if (run != 0) {
159 if (run > fs->e2fs_contigsumsize)
160 run = fs->e2fs_contigsumsize;
161 sump[run]++;
162 }
163 fs->e2fs_clustersum[cg].cs_init = 1;
164 }
165
166 if (fs->e2fs_contigsumsize <= 0)
167 return;
168
169 /* Find the size of the cluster going forward. */
170 start = bno + 1;
171 end = start + fs->e2fs_contigsumsize;
172 if (end > fs->e2fs->e2fs_fpg)
173 end = fs->e2fs->e2fs_fpg;
174 loc = start / NBBY;
175 bit = 1 << (start % NBBY);
176 for (i = start; i < end; i++) {
177 if ((bbp[loc] & bit) != 0)
178 break;
179 if ((i & (NBBY - 1)) != (NBBY - 1))
180 bit <<= 1;
181 else {
182 loc++;
183 bit = 1;
184 }
185 }
186 forw = i - start;
187
188 /* Find the size of the cluster going backward. */
189 start = bno - 1;
190 end = start - fs->e2fs_contigsumsize;
191 if (end < 0)
192 end = -1;
193 loc = start / NBBY;
194 bit = 1 << (start % NBBY);
195 for (i = start; i > end; i--) {
196 if ((bbp[loc] & bit) != 0)
197 break;
198 if ((i & (NBBY - 1)) != 0)
199 bit >>= 1;
200 else {
201 loc--;
202 bit = 1 << (NBBY - 1);
203 }
204 }
205 back = start - i;
206
207 /*
208 * Account for old cluster and the possibly new forward and
209 * back clusters.
210 */
211 i = back + forw + 1;
212 if (i > fs->e2fs_contigsumsize)
213 i = fs->e2fs_contigsumsize;
214 sump[i] += cnt;
215 if (back > 0)
216 sump[back] -= cnt;
217 if (forw > 0)
218 sump[forw] -= cnt;
219
220 /* Update cluster summary information. */
221 lp = &sump[fs->e2fs_contigsumsize];
222 for (i = fs->e2fs_contigsumsize; i > 0; i--)
223 if (*lp-- > 0)
224 break;
225 fs->e2fs_maxcluster[cg] = i;
226 }
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