xref: /dflybsd-src/sys/vfs/ext2fs/ext2_subr.c (revision 4758d649ae1bd804db6736d6e84b9589b414834e)
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 int
73 ext2_bread(struct vnode *vp, off_t loffset, int size, struct buf **bpp)
74 {
75 	struct buf *bp;
76 	int error;
77 
78 	*bpp = NULL;
79 	error = bread(vp, loffset, size, &bp);
80 	if (error) {
81 		ext2_brelse(bp);
82 		return (error);
83 	}
84 
85 	*bpp = bp;
86 	return (0);
87 }
88 
89 int
90 ext2_breadn(struct vnode *vp, off_t loffset, int size, off_t *raoffset,
91     int *rabsize, int cnt, struct buf **bpp)
92 {
93 	struct buf *bp;
94 	int error;
95 
96 	*bpp = NULL;
97 	error = breadn(vp, loffset, size, raoffset, rabsize, cnt, &bp);
98 	if (error) {
99 		ext2_brelse(bp);
100 		return (error);
101 	}
102 
103 	*bpp = bp;
104 	return (0);
105 }
106 
107 int
108 ext2_cluster_read(struct vnode *vp, off_t filesize, off_t loffset, int blksize,
109     size_t minreq, size_t maxreq, struct buf **bpp)
110 {
111 	struct buf *bp;
112 	int error;
113 
114 	*bpp = NULL;
115 	error = cluster_read(vp, filesize, loffset, blksize, minreq, maxreq,
116 	    &bp);
117 	if (error) {
118 		ext2_brelse(bp);
119 		return (error);
120 	}
121 
122 	*bpp = bp;
123 	return (0);
124 }
125 
126 void
127 ext2_brelse(struct buf *bp)
128 {
129 	if (bp == NULL)
130 		return;
131 	brelse(bp);
132 }
133 
134 void
135 ext2_bqrelse(struct buf *bp)
136 {
137 	if (bp == NULL)
138 		return;
139 	bqrelse(bp);
140 }
141 
142 /*
143  * Return buffer with the contents of block "offset" from the beginning of
144  * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
145  * remaining space in the directory.
146  */
147 int
148 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
149 {
150 	struct inode *ip;
151 	struct m_ext2fs *fs;
152 	struct buf *bp;
153 	e2fs_lbn_t lbn;
154 	int error, bsize;
155 
156 	ip = VTOI(vp);
157 	fs = ip->i_e2fs;
158 	lbn = lblkno(fs, offset);
159 	bsize = blksize(fs, ip, lbn);
160 
161 	if ((error = ext2_bread(vp, lblktodoff(fs, lbn), bsize, &bp)) != 0) {
162 		ext2_brelse(bp);
163 		return (error);
164 	}
165 	error = ext2_dir_blk_csum_verify(ip, bp);
166 	if (error != 0) {
167 		ext2_brelse(bp);
168 		return (error);
169 	}
170 	if (res)
171 		*res = (char *)bp->b_data + blkoff(fs, offset);
172 
173 	*bpp = bp;
174 
175 	return (0);
176 }
177 
178 /*
179  * Update the cluster map because of an allocation of free like ffs.
180  *
181  * Cnt == 1 means free; cnt == -1 means allocating.
182  */
183 void
184 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt)
185 {
186 	int32_t *sump = fs->e2fs_clustersum[cg].cs_sum;
187 	int32_t *lp;
188 	e4fs_daddr_t start, end, loc, forw, back;
189 	int bit, i;
190 
191 	/* Initialize the cluster summary array. */
192 	if (fs->e2fs_clustersum[cg].cs_init == 0) {
193 		int run = 0;
194 
195 		bit = 1;
196 		loc = 0;
197 
198 		for (i = 0; i < fs->e2fs_fpg; i++) {
199 			if ((bbp[loc] & bit) == 0)
200 				run++;
201 			else if (run != 0) {
202 				if (run > fs->e2fs_contigsumsize)
203 					run = fs->e2fs_contigsumsize;
204 				sump[run]++;
205 				run = 0;
206 			}
207 			if ((i & (NBBY - 1)) != (NBBY - 1))
208 				bit <<= 1;
209 			else {
210 				loc++;
211 				bit = 1;
212 			}
213 		}
214 		if (run != 0) {
215 			if (run > fs->e2fs_contigsumsize)
216 				run = fs->e2fs_contigsumsize;
217 			sump[run]++;
218 		}
219 		fs->e2fs_clustersum[cg].cs_init = 1;
220 	}
221 
222 	if (fs->e2fs_contigsumsize <= 0)
223 		return;
224 
225 	/* Find the size of the cluster going forward. */
226 	start = bno + 1;
227 	end = start + fs->e2fs_contigsumsize;
228 	if (end > fs->e2fs_fpg)
229 		end = fs->e2fs_fpg;
230 	loc = start / NBBY;
231 	bit = 1 << (start % NBBY);
232 	for (i = start; i < end; i++) {
233 		if ((bbp[loc] & bit) != 0)
234 			break;
235 		if ((i & (NBBY - 1)) != (NBBY - 1))
236 			bit <<= 1;
237 		else {
238 			loc++;
239 			bit = 1;
240 		}
241 	}
242 	forw = i - start;
243 
244 	/* Find the size of the cluster going backward. */
245 	start = bno - 1;
246 	end = start - fs->e2fs_contigsumsize;
247 	if (end < 0)
248 		end = -1;
249 	loc = start / NBBY;
250 	bit = 1 << (start % NBBY);
251 	for (i = start; i > end; i--) {
252 		if ((bbp[loc] & bit) != 0)
253 			break;
254 		if ((i & (NBBY - 1)) != 0)
255 			bit >>= 1;
256 		else {
257 			loc--;
258 			bit = 1 << (NBBY - 1);
259 		}
260 	}
261 	back = start - i;
262 
263 	/*
264 	 * Account for old cluster and the possibly new forward and
265 	 * back clusters.
266 	 */
267 	i = back + forw + 1;
268 	if (i > fs->e2fs_contigsumsize)
269 		i = fs->e2fs_contigsumsize;
270 	sump[i] += cnt;
271 	if (back > 0)
272 		sump[back] -= cnt;
273 	if (forw > 0)
274 		sump[forw] -= cnt;
275 
276 	/* Update cluster summary information. */
277 	lp = &sump[fs->e2fs_contigsumsize];
278 	for (i = fs->e2fs_contigsumsize; i > 0; i--)
279 		if (*lp-- > 0)
280 			break;
281 	fs->e2fs_maxcluster[cg] = i;
282 }
283