xref: /openbsd/sys/ufs/ffs/ffs_subr.c (revision 404b540a)
1 /*	$OpenBSD: ffs_subr.c,v 1.24 2009/08/14 13:05:08 jasper Exp $	*/
2 /*	$NetBSD: ffs_subr.c,v 1.6 1996/03/17 02:16:23 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)ffs_subr.c	8.2 (Berkeley) 9/21/93
33  */
34 
35 #include <sys/param.h>
36 #include <ufs/ffs/fs.h>
37 
38 #ifdef _KERNEL
39 #include <sys/systm.h>
40 #include <sys/vnode.h>
41 #include <sys/mount.h>
42 #include <sys/buf.h>
43 
44 #include <ufs/ufs/quota.h>
45 #include <ufs/ufs/inode.h>
46 #include <ufs/ufs/ufsmount.h>
47 #include <ufs/ufs/ufs_extern.h>
48 
49 #include <ufs/ffs/ffs_extern.h>
50 
51 /*
52  * Return buffer with the contents of block "offset" from the beginning of
53  * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
54  * remaining space in the directory.
55  */
56 int
57 ffs_bufatoff(struct inode *ip, off_t offset, char **res, struct buf **bpp)
58 {
59 	struct fs *fs;
60 	struct vnode *vp;
61 	struct buf *bp;
62 	daddr64_t lbn;
63 	int bsize, error;
64 
65 	vp = ITOV(ip);
66 	fs = ip->i_fs;
67 	lbn = lblkno(fs, offset);
68 	bsize = blksize(fs, ip, lbn);
69 
70 	*bpp = NULL;
71 	if ((error = bread(vp, lbn, fs->fs_bsize, NOCRED, &bp)) != 0) {
72 		brelse(bp);
73 		return (error);
74 	}
75 	bp->b_bcount = bsize;
76 	if (res)
77 		*res = (char *)bp->b_data + blkoff(fs, offset);
78 	*bpp = bp;
79 	return (0);
80 }
81 #else
82 /* Prototypes for userland */
83 void	ffs_fragacct(struct fs *, int, int32_t[], int);
84 int	ffs_isfreeblock(struct fs *, u_char *, daddr64_t);
85 int	ffs_isblock(struct fs *, u_char *, daddr64_t);
86 void	ffs_clrblock(struct fs *, u_char *, daddr64_t);
87 void	ffs_setblock(struct fs *, u_char *, daddr64_t);
88 __dead void panic(const char *, ...);
89 #endif
90 
91 /*
92  * Update the frsum fields to reflect addition or deletion
93  * of some frags.
94  */
95 void
96 ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt)
97 {
98 	int inblk;
99 	int field, subfield;
100 	int siz, pos;
101 
102 	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
103 	fragmap <<= 1;
104 	for (siz = 1; siz < fs->fs_frag; siz++) {
105 		if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
106 			continue;
107 		field = around[siz];
108 		subfield = inside[siz];
109 		for (pos = siz; pos <= fs->fs_frag; pos++) {
110 			if ((fragmap & field) == subfield) {
111 				fraglist[siz] += cnt;
112 				pos += siz;
113 				field <<= siz;
114 				subfield <<= siz;
115 			}
116 			field <<= 1;
117 			subfield <<= 1;
118 		}
119 	}
120 }
121 
122 #if defined(_KERNEL) && defined(DIAGNOSTIC)
123 void
124 ffs_checkoverlap(struct buf *bp, struct inode *ip)
125 {
126 	daddr64_t start, last;
127 	struct vnode *vp;
128 	struct buf *ep;
129 
130 	start = bp->b_blkno;
131 	last = start + btodb(bp->b_bcount) - 1;
132 	LIST_FOREACH(ep, &bufhead, b_list) {
133 		if (ep == bp || (ep->b_flags & B_INVAL) ||
134 		    ep->b_vp == NULLVP)
135 			continue;
136 		if (VOP_BMAP(ep->b_vp, (daddr64_t)0, &vp, (daddr64_t)0, NULL))
137 			continue;
138 		if (vp != ip->i_devvp)
139 			continue;
140 		/* look for overlap */
141 		if (ep->b_bcount == 0 || ep->b_blkno > last ||
142 		    ep->b_blkno + btodb(ep->b_bcount) <= start)
143 			continue;
144 		vprint("Disk overlap", vp);
145 		(void)printf("\tstart %lld, end %lld overlap start %llu, end %llu\n",
146 			start, last, ep->b_blkno,
147 			ep->b_blkno + btodb(ep->b_bcount) - 1);
148 		panic("Disk buffer overlap");
149 	}
150 }
151 #endif /* DIAGNOSTIC */
152 
153 /*
154  * block operations
155  *
156  * check if a block is available
157  */
158 int
159 ffs_isblock(struct fs *fs, u_char *cp, daddr64_t h)
160 {
161 	u_char mask;
162 
163 	switch (fs->fs_frag) {
164 	default:
165 	case 8:
166 		return (cp[h] == 0xff);
167 	case 4:
168 		mask = 0x0f << ((h & 0x1) << 2);
169 		return ((cp[h >> 1] & mask) == mask);
170 	case 2:
171 		mask = 0x03 << ((h & 0x3) << 1);
172 		return ((cp[h >> 2] & mask) == mask);
173 	case 1:
174 		mask = 0x01 << (h & 0x7);
175 		return ((cp[h >> 3] & mask) == mask);
176 	}
177 }
178 
179 /*
180  * take a block out of the map
181  */
182 void
183 ffs_clrblock(struct fs *fs, u_char *cp, daddr64_t h)
184 {
185 
186 	switch (fs->fs_frag) {
187 	default:
188 	case 8:
189 		cp[h] = 0;
190 		return;
191 	case 4:
192 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
193 		return;
194 	case 2:
195 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
196 		return;
197 	case 1:
198 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
199 		return;
200 	}
201 }
202 
203 /*
204  * put a block into the map
205  */
206 void
207 ffs_setblock(struct fs *fs, u_char *cp, daddr64_t h)
208 {
209 
210 	switch (fs->fs_frag) {
211 	default:
212 	case 8:
213 		cp[h] = 0xff;
214 		return;
215 	case 4:
216 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
217 		return;
218 	case 2:
219 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
220 		return;
221 	case 1:
222 		cp[h >> 3] |= (0x01 << (h & 0x7));
223 		return;
224 	}
225 }
226 
227 /*
228  * check if a block is free
229  */
230 int
231 ffs_isfreeblock(struct fs *fs, u_char *cp, daddr64_t h)
232 {
233 
234 	switch (fs->fs_frag) {
235 	default:
236 	case 8:
237 		return (cp[h] == 0);
238 	case 4:
239 		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
240 	case 2:
241 		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
242 	case 1:
243 		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
244 	}
245 }
246