xref: /dragonfly/sys/vfs/ext2fs/ext2_subr.c (revision 2b7dbe20)
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  *	@(#)ffs_subr.c	8.2 (Berkeley) 9/21/93
38  * $FreeBSD$
39  */
40 
41 #include <sys/param.h>
42 
43 #include <sys/proc.h>
44 #include <sys/systm.h>
45 #include <sys/bio.h>
46 #include <sys/buf2.h>
47 #include <sys/lock.h>
48 #include <sys/ucred.h>
49 #include <sys/vnode.h>
50 #include <sys/mount.h>
51 #include <sys/malloc.h>
52 
53 #include <vfs/ext2fs/fs.h>
54 #include <vfs/ext2fs/inode.h>
55 #include <vfs/ext2fs/ext2fs.h>
56 #include <vfs/ext2fs/ext2_extern.h>
57 #include <vfs/ext2fs/fs.h>
58 #include <vfs/ext2fs/ext2_extents.h>
59 #include <vfs/ext2fs/ext2_mount.h>
60 #include <vfs/ext2fs/ext2_dinode.h>
61 
62 void
63 ext2_free(void *addr, struct malloc_type *type, const char *func)
64 {
65 	if (addr == NULL) {
66 		printf("%s: trying to free NULL pointer\n", func);
67 		return;
68 	}
69 	kfree(addr, type);
70 }
71 
72 /*
73  * Return buffer with the contents of block "offset" from the beginning of
74  * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
75  * remaining space in the directory.
76  */
77 int
78 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
79 {
80 	struct inode *ip;
81 	struct m_ext2fs *fs;
82 	struct buf *bp;
83 	e2fs_lbn_t lbn;
84 	int error, bsize;
85 
86 	ip = VTOI(vp);
87 	fs = ip->i_e2fs;
88 	lbn = lblkno(fs, offset);
89 	bsize = blksize(fs, ip, lbn);
90 
91 	if ((error = bread(vp, lblktodoff(fs, lbn), bsize, &bp)) != 0) {
92 		brelse(bp);
93 		return (error);
94 	}
95 	error = ext2_dir_blk_csum_verify(ip, bp);
96 	if (error != 0) {
97 		brelse(bp);
98 		return (error);
99 	}
100 	if (res)
101 		*res = (char *)bp->b_data + blkoff(fs, offset);
102 
103 	*bpp = bp;
104 
105 	return (0);
106 }
107 
108 /*
109  * Update the cluster map because of an allocation of free like ffs.
110  *
111  * Cnt == 1 means free; cnt == -1 means allocating.
112  */
113 void
114 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt)
115 {
116 	int32_t *sump = fs->e2fs_clustersum[cg].cs_sum;
117 	int32_t *lp;
118 	e4fs_daddr_t start, end, loc, forw, back;
119 	int bit, i;
120 
121 	/* Initialize the cluster summary array. */
122 	if (fs->e2fs_clustersum[cg].cs_init == 0) {
123 		int run = 0;
124 
125 		bit = 1;
126 		loc = 0;
127 
128 		for (i = 0; i < fs->e2fs_fpg; i++) {
129 			if ((bbp[loc] & bit) == 0)
130 				run++;
131 			else if (run != 0) {
132 				if (run > fs->e2fs_contigsumsize)
133 					run = fs->e2fs_contigsumsize;
134 				sump[run]++;
135 				run = 0;
136 			}
137 			if ((i & (NBBY - 1)) != (NBBY - 1))
138 				bit <<= 1;
139 			else {
140 				loc++;
141 				bit = 1;
142 			}
143 		}
144 		if (run != 0) {
145 			if (run > fs->e2fs_contigsumsize)
146 				run = fs->e2fs_contigsumsize;
147 			sump[run]++;
148 		}
149 		fs->e2fs_clustersum[cg].cs_init = 1;
150 	}
151 
152 	if (fs->e2fs_contigsumsize <= 0)
153 		return;
154 
155 	/* Find the size of the cluster going forward. */
156 	start = bno + 1;
157 	end = start + fs->e2fs_contigsumsize;
158 	if (end > fs->e2fs_fpg)
159 		end = fs->e2fs_fpg;
160 	loc = start / NBBY;
161 	bit = 1 << (start % NBBY);
162 	for (i = start; i < end; i++) {
163 		if ((bbp[loc] & bit) != 0)
164 			break;
165 		if ((i & (NBBY - 1)) != (NBBY - 1))
166 			bit <<= 1;
167 		else {
168 			loc++;
169 			bit = 1;
170 		}
171 	}
172 	forw = i - start;
173 
174 	/* Find the size of the cluster going backward. */
175 	start = bno - 1;
176 	end = start - fs->e2fs_contigsumsize;
177 	if (end < 0)
178 		end = -1;
179 	loc = start / NBBY;
180 	bit = 1 << (start % NBBY);
181 	for (i = start; i > end; i--) {
182 		if ((bbp[loc] & bit) != 0)
183 			break;
184 		if ((i & (NBBY - 1)) != 0)
185 			bit >>= 1;
186 		else {
187 			loc--;
188 			bit = 1 << (NBBY - 1);
189 		}
190 	}
191 	back = start - i;
192 
193 	/*
194 	 * Account for old cluster and the possibly new forward and
195 	 * back clusters.
196 	 */
197 	i = back + forw + 1;
198 	if (i > fs->e2fs_contigsumsize)
199 		i = fs->e2fs_contigsumsize;
200 	sump[i] += cnt;
201 	if (back > 0)
202 		sump[back] -= cnt;
203 	if (forw > 0)
204 		sump[forw] -= cnt;
205 
206 	/* Update cluster summary information. */
207 	lp = &sump[fs->e2fs_contigsumsize];
208 	for (i = fs->e2fs_contigsumsize; i > 0; i--)
209 		if (*lp-- > 0)
210 			break;
211 	fs->e2fs_maxcluster[cg] = i;
212 }
213