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/10.1/sys/fs/ext2fs/ext2_subr.c 261311 2014-01-31 03:58:36Z pfg $
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 #include <fs/ext2fs/ext2_extents.h>
54 #include <fs/ext2fs/ext2_mount.h>
55 #include <fs/ext2fs/ext2_dinode.h>
56
57 #ifdef KDB
58 void ext2_checkoverlap(struct buf *, struct inode *);
59 #endif
60
61 /*
62 * Return buffer with the contents of block "offset" from the beginning of
63 * directory "ip". If "res" is non-zero, fill it in with a pointer to the
64 * remaining space in the directory.
65 */
66 int
67 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
68 {
69 struct inode *ip;
70 struct m_ext2fs *fs;
71 struct buf *bp;
72 e2fs_lbn_t lbn;
73 int bsize, error;
74 daddr_t newblk;
75 struct ext4_extent *ep;
76 struct ext4_extent_path path;
77
78 ip = VTOI(vp);
79 fs = ip->i_e2fs;
80 lbn = lblkno(fs, offset);
81 bsize = blksize(fs, ip, lbn);
82 *bpp = NULL;
83
84 /*
85 * IN_E4EXTENTS requires special treatment as we can otherwise fall
86 * back to the normal path.
87 */
88 if (!(ip->i_flag & IN_E4EXTENTS))
89 goto normal;
90
91 memset(&path, 0, sizeof(path));
92 if (ext4_ext_find_extent(fs, ip, lbn, &path) == NULL)
93 goto normal;
94 ep = path.ep_ext;
95 if (ep == NULL)
96 goto normal;
97
98 newblk = lbn - ep->e_blk +
99 (ep->e_start_lo | (daddr_t)ep->e_start_hi << 32);
100
101 if (path.ep_bp != NULL) {
102 brelse(path.ep_bp);
103 path.ep_bp = NULL;
104 }
105 error = bread(ip->i_devvp, fsbtodb(fs, newblk), bsize, NOCRED, &bp);
106 if (error != 0) {
107 brelse(bp);
108 return (error);
109 }
110 if (res)
111 *res = (char *)bp->b_data + blkoff(fs, offset);
112 /*
113 * If IN_E4EXTENTS is enabled we would get a wrong offset so
114 * reset b_offset here.
115 */
116 bp->b_offset = lbn * bsize;
117 *bpp = bp;
118 return (0);
119
120 normal:
121 if (*bpp == NULL) {
122 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) {
123 brelse(bp);
124 return (error);
125 }
126 if (res)
127 *res = (char *)bp->b_data + blkoff(fs, offset);
128 *bpp = bp;
129 }
130 return (0);
131 }
132
133 #ifdef KDB
134 void
135 ext2_checkoverlap(struct buf *bp, struct inode *ip)
136 {
137 struct buf *ebp, *ep;
138 e4fs_daddr_t start, last;
139 struct vnode *vp;
140
141 ebp = &buf[nbuf];
142 start = bp->b_blkno;
143 last = start + btodb(bp->b_bcount) - 1;
144 for (ep = buf; ep < ebp; ep++) {
145 if (ep == bp || (ep->b_flags & B_INVAL))
146 continue;
147 vp = ip->i_ump->um_devvp;
148 /* look for overlap */
149 if (ep->b_bcount == 0 || ep->b_blkno > last ||
150 ep->b_blkno + btodb(ep->b_bcount) <= start)
151 continue;
152 vprint("Disk overlap", vp);
153 printf("\tstart %jd, end %jd overlap start %jd, end %jd\n",
154 (intmax_t)start, (intmax_t)last, (intmax_t)ep->b_blkno,
155 (intmax_t)(ep->b_blkno + btodb(ep->b_bcount) - 1));
156 panic("ext2_checkoverlap: Disk buffer overlap");
157 }
158 }
159 #endif /* KDB */
160
161 /*
162 * Update the cluster map because of an allocation of free like ffs.
163 *
164 * Cnt == 1 means free; cnt == -1 means allocating.
165 */
166 void
167 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, daddr_t bno, int cnt)
168 {
169 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum;
170 int32_t *lp;
171 int back, bit, end, forw, i, loc, start;
172
173 /* Initialize the cluster summary array. */
174 if (fs->e2fs_clustersum[cg].cs_init == 0) {
175 int run = 0;
176 bit = 1;
177 loc = 0;
178
179 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) {
180 if ((bbp[loc] & bit) == 0)
181 run++;
182 else if (run != 0) {
183 if (run > fs->e2fs_contigsumsize)
184 run = fs->e2fs_contigsumsize;
185 sump[run]++;
186 run = 0;
187 }
188 if ((i & (NBBY - 1)) != (NBBY - 1))
189 bit <<= 1;
190 else {
191 loc++;
192 bit = 1;
193 }
194 }
195 if (run != 0) {
196 if (run > fs->e2fs_contigsumsize)
197 run = fs->e2fs_contigsumsize;
198 sump[run]++;
199 }
200 fs->e2fs_clustersum[cg].cs_init = 1;
201 }
202
203 if (fs->e2fs_contigsumsize <= 0)
204 return;
205
206 /* Find the size of the cluster going forward. */
207 start = bno + 1;
208 end = start + fs->e2fs_contigsumsize;
209 if (end > fs->e2fs->e2fs_fpg)
210 end = fs->e2fs->e2fs_fpg;
211 loc = start / NBBY;
212 bit = 1 << (start % NBBY);
213 for (i = start; i < end; i++) {
214 if ((bbp[loc] & bit) != 0)
215 break;
216 if ((i & (NBBY - 1)) != (NBBY - 1))
217 bit <<= 1;
218 else {
219 loc++;
220 bit = 1;
221 }
222 }
223 forw = i - start;
224
225 /* Find the size of the cluster going backward. */
226 start = bno - 1;
227 end = start - fs->e2fs_contigsumsize;
228 if (end < 0)
229 end = -1;
230 loc = start / NBBY;
231 bit = 1 << (start % NBBY);
232 for (i = start; i > end; i--) {
233 if ((bbp[loc] & bit) != 0)
234 break;
235 if ((i & (NBBY - 1)) != 0)
236 bit >>= 1;
237 else {
238 loc--;
239 bit = 1 << (NBBY - 1);
240 }
241 }
242 back = start - i;
243
244 /*
245 * Account for old cluster and the possibly new forward and
246 * back clusters.
247 */
248 i = back + forw + 1;
249 if (i > fs->e2fs_contigsumsize)
250 i = fs->e2fs_contigsumsize;
251 sump[i] += cnt;
252 if (back > 0)
253 sump[back] -= cnt;
254 if (forw > 0)
255 sump[forw] -= cnt;
256
257 /* Update cluster summary information. */
258 lp = &sump[fs->e2fs_contigsumsize];
259 for (i = fs->e2fs_contigsumsize; i > 0; i--)
260 if (*lp-- > 0)
261 break;
262 fs->e2fs_maxcluster[cg] = i;
263 }
Cache object: 9ba87455f843a3f14a38112e13ff7057
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