2 * modified for Lites 1.1
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
8 * Copyright (c) 1982, 1986, 1989, 1993
9 * The Regents of the University of California. All rights reserved.
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20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
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
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35 * @(#)ffs_subr.c 8.2 (Berkeley) 9/21/93
39 #include <sys/param.h>
42 #include <sys/systm.h>
46 #include <sys/ucred.h>
47 #include <sys/vnode.h>
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>
55 #include <fs/ext2fs/ext2_mount.h>
57 void ext2_checkoverlap(struct buf *, struct inode *);
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.
66 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
76 lbn = lblkno(fs, offset);
77 bsize = blksize(fs, ip, lbn);
80 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) {
85 *res = (char *)bp->b_data + blkoff(fs, offset);
92 ext2_checkoverlap(struct buf *bp, struct inode *ip)
100 last = start + btodb(bp->b_bcount) - 1;
101 for (ep = buf; ep < ebp; ep++) {
102 if (ep == bp || (ep->b_flags & B_INVAL))
104 vp = ip->i_ump->um_devvp;
105 /* look for overlap */
106 if (ep->b_bcount == 0 || ep->b_blkno > last ||
107 ep->b_blkno + btodb(ep->b_bcount) <= start)
109 vprint("Disk overlap", vp);
110 (void)printf("\tstart %d, end %d overlap start %lld, end %ld\n",
111 start, last, (long long)ep->b_blkno,
112 (long)(ep->b_blkno + btodb(ep->b_bcount) - 1));
113 panic("Disk buffer overlap");
119 * Update the cluster map because of an allocation of free like ffs.
121 * Cnt == 1 means free; cnt == -1 means allocating.
124 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, daddr_t bno, int cnt)
126 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum;
128 int back, bit, end, forw, i, loc, start;
130 /* Initialize the cluster summary array. */
131 if (fs->e2fs_clustersum[cg].cs_init == 0) {
136 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) {
137 if ((bbp[loc] & bit) == 0)
140 if (run > fs->e2fs_contigsumsize)
141 run = fs->e2fs_contigsumsize;
145 if ((i & (NBBY - 1)) != (NBBY - 1))
153 if (run > fs->e2fs_contigsumsize)
154 run = fs->e2fs_contigsumsize;
157 fs->e2fs_clustersum[cg].cs_init = 1;
160 if (fs->e2fs_contigsumsize <= 0)
163 /* Find the size of the cluster going forward. */
165 end = start + fs->e2fs_contigsumsize;
166 if (end > fs->e2fs->e2fs_fpg)
167 end = fs->e2fs->e2fs_fpg;
169 bit = 1 << (start % NBBY);
170 for (i = start; i < end; i++) {
171 if ((bbp[loc] & bit) != 0)
173 if ((i & (NBBY - 1)) != (NBBY - 1))
182 /* Find the size of the cluster going backward. */
184 end = start - fs->e2fs_contigsumsize;
188 bit = 1 << (start % NBBY);
189 for (i = start; i > end; i--) {
190 if ((bbp[loc] & bit) != 0)
192 if ((i & (NBBY - 1)) != 0)
196 bit = 1 << (NBBY - 1);
202 * Account for old cluster and the possibly new forward and
206 if (i > fs->e2fs_contigsumsize)
207 i = fs->e2fs_contigsumsize;
214 /* Update cluster summary information. */
215 lp = &sump[fs->e2fs_contigsumsize];
216 for (i = fs->e2fs_contigsumsize; i > 0; i--)
219 fs->e2fs_maxcluster[cg] = i;