xref: /freebsd/sys/ufs/ffs/ffs_subr.c (revision df7f5d4de4592a8948a25ce01e5bddfbb7ce39dc)
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  * $Id: ffs_subr.c,v 1.11 1997/02/22 09:47:04 peter Exp $
35  */
36 
37 #include <sys/param.h>
38 
39 #ifndef KERNEL
40 #include <ufs/ufs/dinode.h>
41 #include <ufs/ffs/fs.h>
42 #else
43 #include "opt_ddb.h"
44 
45 #include <sys/systm.h>
46 #include <sys/vnode.h>
47 #include <sys/buf.h>
48 #include <ufs/ufs/quota.h>
49 #include <ufs/ufs/inode.h>
50 #include <ufs/ufs/dinode.h>
51 #include <ufs/ffs/fs.h>
52 #include <ufs/ffs/ffs_extern.h>
53 
54 /*
55  * Return buffer with the contents of block "offset" from the beginning of
56  * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
57  * remaining space in the directory.
58  */
59 int
60 ffs_blkatoff(ap)
61 	struct vop_blkatoff_args /* {
62 		struct vnode *a_vp;
63 		off_t a_offset;
64 		char **a_res;
65 		struct buf **a_bpp;
66 	} */ *ap;
67 {
68 	struct inode *ip;
69 	register struct fs *fs;
70 	struct buf *bp;
71 	ufs_daddr_t lbn;
72 	int bsize, error;
73 
74 	ip = VTOI(ap->a_vp);
75 	fs = ip->i_fs;
76 	lbn = lblkno(fs, ap->a_offset);
77 	bsize = blksize(fs, ip, lbn);
78 
79 	*ap->a_bpp = NULL;
80 	error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp);
81 	if (error) {
82 		brelse(bp);
83 		return (error);
84 	}
85 	if (ap->a_res)
86 		*ap->a_res = (char *)bp->b_data + blkoff(fs, ap->a_offset);
87 	*ap->a_bpp = bp;
88 	return (0);
89 }
90 #endif
91 
92 /*
93  * Update the frsum fields to reflect addition or deletion
94  * of some frags.
95  */
96 void
97 ffs_fragacct(fs, fragmap, fraglist, cnt)
98 	struct fs *fs;
99 	int fragmap;
100 	int32_t fraglist[];
101 	int cnt;
102 {
103 	int inblk;
104 	register int field, subfield;
105 	register int siz, pos;
106 
107 	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
108 	fragmap <<= 1;
109 	for (siz = 1; siz < fs->fs_frag; siz++) {
110 		if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
111 			continue;
112 		field = around[siz];
113 		subfield = inside[siz];
114 		for (pos = siz; pos <= fs->fs_frag; pos++) {
115 			if ((fragmap & field) == subfield) {
116 				fraglist[siz] += cnt;
117 				pos += siz;
118 				field <<= siz;
119 				subfield <<= siz;
120 			}
121 			field <<= 1;
122 			subfield <<= 1;
123 		}
124 	}
125 }
126 
127 #if defined(KERNEL) && defined(DIAGNOSTIC) && defined(DDB)
128 void
129 ffs_checkoverlap(bp, ip)
130 	struct buf *bp;
131 	struct inode *ip;
132 {
133 	register struct buf *ebp, *ep;
134 	register ufs_daddr_t start, last;
135 	struct vnode *vp;
136 
137 	ebp = &buf[nbuf];
138 	start = bp->b_blkno;
139 	last = start + btodb(bp->b_bcount) - 1;
140 	for (ep = buf; ep < ebp; ep++) {
141 		if (ep == bp || (ep->b_flags & B_INVAL) ||
142 		    ep->b_vp == NULLVP)
143 			continue;
144 		if (VOP_BMAP(ep->b_vp, (ufs_daddr_t)0, &vp, (ufs_daddr_t)0,
145 		    NULL, NULL))
146 			continue;
147 		if (vp != ip->i_devvp)
148 			continue;
149 		/* look for overlap */
150 		if (ep->b_bcount == 0 || ep->b_blkno > last ||
151 		    ep->b_blkno + btodb(ep->b_bcount) <= start)
152 			continue;
153 		vprint("Disk overlap", vp);
154 		(void)printf("\tstart %lu, end %lu overlap start %lu, end %lu\n",
155 			(u_long)start, (u_long)last, (u_long)ep->b_blkno,
156 			(u_long)(ep->b_blkno + btodb(ep->b_bcount) - 1));
157 		panic("ffs_checkoverlap: Disk buffer overlap");
158 	}
159 }
160 #endif /* DIAGNOSTIC */
161 
162 /*
163  * block operations
164  *
165  * check if a block is available
166  */
167 int
168 ffs_isblock(fs, cp, h)
169 	struct fs *fs;
170 	unsigned char *cp;
171 	ufs_daddr_t h;
172 {
173 	unsigned char mask;
174 
175 	switch ((int)fs->fs_frag) {
176 	case 8:
177 		return (cp[h] == 0xff);
178 	case 4:
179 		mask = 0x0f << ((h & 0x1) << 2);
180 		return ((cp[h >> 1] & mask) == mask);
181 	case 2:
182 		mask = 0x03 << ((h & 0x3) << 1);
183 		return ((cp[h >> 2] & mask) == mask);
184 	case 1:
185 		mask = 0x01 << (h & 0x7);
186 		return ((cp[h >> 3] & mask) == mask);
187 	default:
188 		panic("ffs_isblock");
189 	}
190 }
191 
192 /*
193  * take a block out of the map
194  */
195 void
196 ffs_clrblock(fs, cp, h)
197 	struct fs *fs;
198 	u_char *cp;
199 	ufs_daddr_t h;
200 {
201 
202 	switch ((int)fs->fs_frag) {
203 	case 8:
204 		cp[h] = 0;
205 		return;
206 	case 4:
207 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
208 		return;
209 	case 2:
210 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
211 		return;
212 	case 1:
213 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
214 		return;
215 	default:
216 		panic("ffs_clrblock");
217 	}
218 }
219 
220 /*
221  * put a block into the map
222  */
223 void
224 ffs_setblock(fs, cp, h)
225 	struct fs *fs;
226 	unsigned char *cp;
227 	ufs_daddr_t h;
228 {
229 
230 	switch ((int)fs->fs_frag) {
231 
232 	case 8:
233 		cp[h] = 0xff;
234 		return;
235 	case 4:
236 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
237 		return;
238 	case 2:
239 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
240 		return;
241 	case 1:
242 		cp[h >> 3] |= (0x01 << (h & 0x7));
243 		return;
244 	default:
245 		panic("ffs_setblock");
246 	}
247 }
248