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 * SPDX-License-Identifier: BSD-3-Clause
9 *
10 * Copyright (c) 1982, 1986, 1989, 1993
11 * The Regents of the University of California. All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38 #include <sys/param.h>
39
40 #include <sys/proc.h>
41 #include <sys/sdt.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/fs.h>
50 #include <fs/ext2fs/inode.h>
51 #include <fs/ext2fs/ext2fs.h>
52 #include <fs/ext2fs/ext2_extern.h>
53 #include <fs/ext2fs/fs.h>
54 #include <fs/ext2fs/ext2_extents.h>
55 #include <fs/ext2fs/ext2_mount.h>
56 #include <fs/ext2fs/ext2_dinode.h>
57
58 /*
59 * Return buffer with the contents of block "offset" from the beginning of
60 * directory "ip". If "res" is non-zero, fill it in with a pointer to the
61 * remaining space in the directory.
62 */
63 int
ext2_blkatoff(struct vnode * vp,off_t offset,char ** res,struct buf ** bpp)64 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
65 {
66 struct inode *ip;
67 struct m_ext2fs *fs;
68 struct buf *bp;
69 e2fs_lbn_t lbn;
70 int error, bsize;
71
72 ip = VTOI(vp);
73 fs = ip->i_e2fs;
74 lbn = lblkno(fs, offset);
75 bsize = blksize(fs, ip, lbn);
76
77 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) {
78 brelse(bp);
79 return (error);
80 }
81 error = ext2_dir_blk_csum_verify(ip, bp);
82 if (error != 0) {
83 brelse(bp);
84 return (error);
85 }
86 if (res)
87 *res = (char *)bp->b_data + blkoff(fs, offset);
88
89 *bpp = bp;
90
91 return (0);
92 }
93
94 /*
95 * Update the cluster map because of an allocation of free like ffs.
96 *
97 * Cnt == 1 means free; cnt == -1 means allocating.
98 */
99 void
ext2_clusteracct(struct m_ext2fs * fs,char * bbp,int cg,e4fs_daddr_t bno,int cnt)100 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt)
101 {
102 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum;
103 int32_t *lp;
104 e4fs_daddr_t start, end, loc, forw, back;
105 int bit, i;
106
107 /* Initialize the cluster summary array. */
108 if (fs->e2fs_clustersum[cg].cs_init == 0) {
109 int run = 0;
110
111 bit = 1;
112 loc = 0;
113
114 for (i = 0; i < fs->e2fs_fpg; i++) {
115 if ((bbp[loc] & bit) == 0)
116 run++;
117 else if (run != 0) {
118 if (run > fs->e2fs_contigsumsize)
119 run = fs->e2fs_contigsumsize;
120 sump[run]++;
121 run = 0;
122 }
123 if ((i & (NBBY - 1)) != (NBBY - 1))
124 bit <<= 1;
125 else {
126 loc++;
127 bit = 1;
128 }
129 }
130 if (run != 0) {
131 if (run > fs->e2fs_contigsumsize)
132 run = fs->e2fs_contigsumsize;
133 sump[run]++;
134 }
135 fs->e2fs_clustersum[cg].cs_init = 1;
136 }
137
138 if (fs->e2fs_contigsumsize <= 0)
139 return;
140
141 /* Find the size of the cluster going forward. */
142 start = bno + 1;
143 end = start + fs->e2fs_contigsumsize;
144 if (end > fs->e2fs_fpg)
145 end = fs->e2fs_fpg;
146 loc = start / NBBY;
147 bit = 1 << (start % NBBY);
148 for (i = start; i < end; i++) {
149 if ((bbp[loc] & bit) != 0)
150 break;
151 if ((i & (NBBY - 1)) != (NBBY - 1))
152 bit <<= 1;
153 else {
154 loc++;
155 bit = 1;
156 }
157 }
158 forw = i - start;
159
160 /* Find the size of the cluster going backward. */
161 start = bno - 1;
162 end = start - fs->e2fs_contigsumsize;
163 if (end < 0)
164 end = -1;
165 loc = start / NBBY;
166 bit = 1 << (start % NBBY);
167 for (i = start; i > end; i--) {
168 if ((bbp[loc] & bit) != 0)
169 break;
170 if ((i & (NBBY - 1)) != 0)
171 bit >>= 1;
172 else {
173 loc--;
174 bit = 1 << (NBBY - 1);
175 }
176 }
177 back = start - i;
178
179 /*
180 * Account for old cluster and the possibly new forward and
181 * back clusters.
182 */
183 i = back + forw + 1;
184 if (i > fs->e2fs_contigsumsize)
185 i = fs->e2fs_contigsumsize;
186 sump[i] += cnt;
187 if (back > 0)
188 sump[back] -= cnt;
189 if (forw > 0)
190 sump[forw] -= cnt;
191
192 /* Update cluster summary information. */
193 lp = &sump[fs->e2fs_contigsumsize];
194 for (i = fs->e2fs_contigsumsize; i > 0; i--)
195 if (*lp-- > 0)
196 break;
197 fs->e2fs_maxcluster[cg] = i;
198 }
199