Annotation of sys/ufs/ffs/ffs_subr.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: ffs_subr.c,v 1.20 2007/05/26 20:26:51 pedro 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: daddr_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 *, unsigned char *, daddr_t);
85: int ffs_isblock(struct fs *, unsigned char *, daddr_t);
86: void ffs_clrblock(struct fs *, u_char *, daddr_t);
87: void ffs_setblock(struct fs *, unsigned char *, daddr_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: daddr_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, (daddr_t)0, &vp, (daddr_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 %d, end %d overlap start %d, end %ld\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, unsigned char *cp, daddr_t h)
160: {
161: unsigned 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, daddr_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, unsigned char *cp, daddr_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, unsigned char *cp, daddr_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: }
CVSweb
![[BACK]](/icons/back.gif){kind=icon}
Return to ffs_subr.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / sys / ufs / ffs