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 * Copyright (c) 1982, 1986, 1989, 1993
9 * The Regents of the University of California. All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)ffs_subr.c 8.2 (Berkeley) 9/21/93
36 * $FreeBSD: releng/9.0/sys/fs/ext2fs/ext2_subr.c 217594 2011-01-19 19:49:48Z jhb $
37 */
38
39 #include <sys/param.h>
40
41 #include <sys/proc.h>
42 #include <sys/systm.h>
43 #include <sys/bio.h>
44 #include <sys/buf.h>
45 #include <sys/lock.h>
46 #include <sys/ucred.h>
47 #include <sys/vnode.h>
48
49 #include <fs/ext2fs/inode.h>
50 #include <fs/ext2fs/ext2_extern.h>
51 #include <fs/ext2fs/ext2fs.h>
52 #include <fs/ext2fs/fs.h>
53
54 #ifdef KDB
55 #include <fs/ext2fs/ext2_mount.h>
56
57 void ext2_checkoverlap(struct buf *, struct inode *);
58 #endif
59
60 /*
61 * Return buffer with the contents of block "offset" from the beginning of
62 * directory "ip". If "res" is non-zero, fill it in with a pointer to the
63 * remaining space in the directory.
64 */
65 int
66 ext2_blkatoff(vp, offset, res, bpp)
67 struct vnode *vp;
68 off_t offset;
69 char **res;
70 struct buf **bpp;
71 {
72 struct inode *ip;
73 struct m_ext2fs *fs;
74 struct buf *bp;
75 int32_t lbn;
76 int bsize, error;
77
78 ip = VTOI(vp);
79 fs = ip->i_e2fs;
80 lbn = lblkno(fs, offset);
81 bsize = blksize(fs, ip, lbn);
82
83 *bpp = NULL;
84 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) {
85 brelse(bp);
86 return (error);
87 }
88 if (res)
89 *res = (char *)bp->b_data + blkoff(fs, offset);
90 *bpp = bp;
91 return (0);
92 }
93
94 #ifdef KDB
95 void
96 ext2_checkoverlap(bp, ip)
97 struct buf *bp;
98 struct inode *ip;
99 {
100 struct buf *ebp, *ep;
101 int32_t start, last;
102 struct vnode *vp;
103
104 ebp = &buf[nbuf];
105 start = bp->b_blkno;
106 last = start + btodb(bp->b_bcount) - 1;
107 for (ep = buf; ep < ebp; ep++) {
108 if (ep == bp || (ep->b_flags & B_INVAL))
109 continue;
110 vp = ip->i_ump->um_devvp;
111 /* look for overlap */
112 if (ep->b_bcount == 0 || ep->b_blkno > last ||
113 ep->b_blkno + btodb(ep->b_bcount) <= start)
114 continue;
115 vprint("Disk overlap", vp);
116 (void)printf("\tstart %d, end %d overlap start %lld, end %ld\n",
117 start, last, (long long)ep->b_blkno,
118 (long)(ep->b_blkno + btodb(ep->b_bcount) - 1));
119 panic("Disk buffer overlap");
120 }
121 }
122 #endif /* KDB */
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