1 /* $OpenBSD: ext2fs_bmap.c,v 1.15 2007/06/17 20:15:25 jasper Exp $ */
2 /* $NetBSD: ext2fs_bmap.c,v 1.5 2000/03/30 12:41:11 augustss Exp $ */
3
4 /*
5 * Copyright (c) 1997 Manuel Bouyer.
6 * Copyright (c) 1989, 1991, 1993
7 * The Regents of the University of California. All rights reserved.
8 * (c) UNIX System Laboratories, Inc.
9 * All or some portions of this file are derived from material licensed
10 * to the University of California by American Telephone and Telegraph
11 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
12 * the permission of UNIX System Laboratories, Inc.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94
39 * Modified for ext2fs by Manuel Bouyer.
40 */
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/buf.h>
45 #include <sys/proc.h>
46 #include <sys/vnode.h>
47 #include <sys/mount.h>
48 #include <sys/resourcevar.h>
49
50 #include <miscfs/specfs/specdev.h>
51
52 #include <ufs/ufs/quota.h>
53 #include <ufs/ufs/inode.h>
54 #include <ufs/ufs/ufsmount.h>
55 #include <ufs/ufs/ufs_extern.h>
56 #include <ufs/ext2fs/ext2fs.h>
57 #include <ufs/ext2fs/ext2fs_extern.h>
58
59 static int ext2fs_bmaparray(struct vnode *, int32_t, daddr64_t *,
60 struct indir *, int *, int *);
61
62 /*
63 * Bmap converts a the logical block number of a file to its physical block
64 * number on the disk. The conversion is done by using the logical block
65 * number to index into the array of block pointers described by the dinode.
66 */
67 int
68 ext2fs_bmap(void *v)
69 {
70 struct vop_bmap_args *ap = v;
71 /*
72 * Check for underlying vnode requests and ensure that logical
73 * to physical mapping is requested.
74 */
75 if (ap->a_vpp != NULL)
76 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp;
77 if (ap->a_bnp == NULL)
78 return (0);
79
80 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL,
81 ap->a_runp));
82 }
83
84 /*
85 * Indirect blocks are now on the vnode for the file. They are given negative
86 * logical block numbers. Indirect blocks are addressed by the negative
87 * address of the first data block to which they point. Double indirect blocks
88 * are addressed by one less than the address of the first indirect block to
89 * which they point. Triple indirect blocks are addressed by one less than
90 * the address of the first double indirect block to which they point.
91 *
92 * ext2fs_bmaparray does the bmap conversion, and if requested returns the
93 * array of logical blocks which must be traversed to get to a block.
94 * Each entry contains the offset into that block that gets you to the
95 * next block and the disk address of the block (if it is assigned).
96 */
97
98 int
99 ext2fs_bmaparray(struct vnode *vp, int32_t bn, daddr64_t *bnp,
100 struct indir *ap, int *nump, int *runp)
101 {
102 struct inode *ip;
103 struct buf *bp;
104 struct ufsmount *ump;
105 struct mount *mp;
106 struct vnode *devvp;
107 struct indir a[NIADDR+1], *xap;
108 int32_t daddr;
109 long metalbn;
110 int error, maxrun = 0, num;
111
112 ip = VTOI(vp);
113 mp = vp->v_mount;
114 ump = VFSTOUFS(mp);
115 #ifdef DIAGNOSTIC
116 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL))
117 panic("ext2fs_bmaparray: invalid arguments");
118 #endif
119
120 if (runp) {
121 /*
122 * XXX
123 * If MAXBSIZE is the largest transfer the disks can handle,
124 * we probably want maxrun to be 1 block less so that we
125 * don't create a block larger than the device can handle.
126 */
127 *runp = 0;
128 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1;
129 }
130
131 xap = ap == NULL ? a : ap;
132 if (!nump)
133 nump = #
134 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0)
135 return (error);
136
137 num = *nump;
138 if (num == 0) {
139 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn]));
140 if (*bnp == 0)
141 *bnp = -1;
142 else if (runp)
143 for (++bn; bn < NDADDR && *runp < maxrun &&
144 is_sequential(ump, fs2h32(ip->i_e2fs_blocks[bn - 1]),
145 fs2h32(ip->i_e2fs_blocks[bn]));
146 ++bn, ++*runp);
147 return (0);
148 }
149
150
151 /* Get disk address out of indirect block array */
152 daddr = fs2h32(ip->i_e2fs_blocks[NDADDR + xap->in_off]);
153
154 devvp = VFSTOUFS(vp->v_mount)->um_devvp;
155
156 #ifdef DIAGNOSTIC
157 if (num > NIADDR + 1 || num < 1) {
158 printf("ext2fs_bmaparray: num=%d\n", num);
159 panic("ext2fs_bmaparray: num");
160 }
161 #endif
162 for (bp = NULL, ++xap; --num; ++xap) {
163 /*
164 * Exit the loop if there is no disk address assigned yet and
165 * the indirect block isn't in the cache, or if we were
166 * looking for an indirect block and we've found it.
167 */
168
169 metalbn = xap->in_lbn;
170 if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn)
171 break;
172 /*
173 * If we get here, we've either got the block in the cache
174 * or we have a disk address for it, go fetch it.
175 */
176 if (bp)
177 brelse(bp);
178
179 xap->in_exists = 1;
180 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0);
181 if (bp->b_flags & (B_DONE | B_DELWRI)) {
182 ;
183 }
184 #ifdef DIAGNOSTIC
185 else if (!daddr)
186 panic("ext2fs_bmaparry: indirect block not in cache");
187 #endif
188 else {
189 bp->b_blkno = blkptrtodb(ump, daddr);
190 bp->b_flags |= B_READ;
191 VOP_STRATEGY(bp);
192 curproc->p_stats->p_ru.ru_inblock++; /* XXX */
193 if ((error = biowait(bp)) != 0) {
194 brelse(bp);
195 return (error);
196 }
197 }
198
199 daddr = fs2h32(((int32_t *)bp->b_data)[xap->in_off]);
200 if (num == 1 && daddr && runp)
201 for (bn = xap->in_off + 1;
202 bn < MNINDIR(ump) && *runp < maxrun &&
203 is_sequential(ump, ((int32_t *)bp->b_data)[bn - 1],
204 ((int32_t *)bp->b_data)[bn]);
205 ++bn, ++*runp);
206 }
207 if (bp)
208 brelse(bp);
209
210 daddr = blkptrtodb(ump, daddr);
211 *bnp = daddr == 0 ? -1 : daddr;
212 return (0);
213 }