1 /* $OpenBSD: ext2fs_bmap.c,v 1.29 2024/04/13 23:44:11 jsg 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/specdev.h>
49
50 #include <ufs/ufs/quota.h>
51 #include <ufs/ufs/inode.h>
52 #include <ufs/ufs/ufsmount.h>
53 #include <ufs/ufs/ufs_extern.h>
54 #include <ufs/ext2fs/ext2fs.h>
55 #include <ufs/ext2fs/ext2fs_extents.h>
56 #include <ufs/ext2fs/ext2fs_extern.h>
57
58 static int ext4_bmapext(struct vnode *, daddr_t, daddr_t *, struct indir *,
59 int *, int *);
60 static int ext2fs_bmaparray(struct vnode *, daddr_t, daddr_t *, struct indir *,
61 int *, int *);
62
63 /*
64 * Bmap converts a the logical block number of a file to its physical block
65 * number on the disk. The conversion is done by using the logical block
66 * number to index into the array of block pointers described by the dinode.
67 */
68 int
ext2fs_bmap(void * v)69 ext2fs_bmap(void *v)
70 {
71 struct vop_bmap_args *ap = v;
72
73 /*
74 * Check for underlying vnode requests and ensure that logical
75 * to physical mapping is requested.
76 */
77 if (ap->a_vpp != NULL)
78 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp;
79 if (ap->a_bnp == NULL)
80 return (0);
81
82 if (VTOI(ap->a_vp)->i_e2din->e2di_flags & EXT4_EXTENTS) {
83 return (ext4_bmapext(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL,
84 ap->a_runp));
85 }
86 return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL,
87 ap->a_runp));
88 }
89
90 /*
91 * Logical block number of a file -> physical block number on disk within ext4 extents.
92 */
93 int
ext4_bmapext(struct vnode * vp,daddr_t bn,daddr_t * bnp,struct indir * ap,int * nump,int * runp)94 ext4_bmapext(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap, int *nump, int *runp)
95 {
96 struct inode *ip;
97 struct m_ext2fs *fs;
98 struct ext4_extent *ep;
99 struct ext4_extent_path path;
100 daddr_t pos;
101
102 ip = VTOI(vp);
103 fs = ip->i_e2fs;
104
105 if (runp != NULL)
106 *runp = 0;
107 if (nump != NULL)
108 *nump = 0;
109
110 ext4_ext_find_extent(fs, ip, bn, &path);
111 if ((ep = path.ep_ext) == NULL)
112 return (EIO);
113
114 pos = bn - ep->e_blk + (((daddr_t)ep->e_start_hi << 32) | ep->e_start_lo);
115 if ((*bnp = fsbtodb(fs, pos)) == 0)
116 *bnp = -1;
117 return (0);
118 }
119
120 /*
121 * Indirect blocks are now on the vnode for the file. They are given negative
122 * logical block numbers. Indirect blocks are addressed by the negative
123 * address of the first data block to which they point. Double indirect blocks
124 * are addressed by one less than the address of the first indirect block to
125 * which they point. Triple indirect blocks are addressed by one less than
126 * the address of the first double indirect block to which they point.
127 *
128 * ext2fs_bmaparray does the bmap conversion, and if requested returns the
129 * array of logical blocks which must be traversed to get to a block.
130 * Each entry contains the offset into that block that gets you to the
131 * next block and the disk address of the block (if it is assigned).
132 */
133
134 int
ext2fs_bmaparray(struct vnode * vp,daddr_t bn,daddr_t * bnp,struct indir * ap,int * nump,int * runp)135 ext2fs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp,
136 struct indir *ap, int *nump, int *runp)
137 {
138 struct inode *ip;
139 struct buf *bp;
140 struct ufsmount *ump;
141 struct mount *mp;
142 struct vnode *devvp;
143 struct indir a[NIADDR+1], *xap;
144 int32_t daddr;
145 long metalbn;
146 int error, maxrun = 0, num;
147
148 ip = VTOI(vp);
149 mp = vp->v_mount;
150 ump = VFSTOUFS(mp);
151 #ifdef DIAGNOSTIC
152 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL))
153 panic("ext2fs_bmaparray: invalid arguments");
154 #endif
155
156 if (runp) {
157 /*
158 * XXX
159 * If MAXBSIZE is the largest transfer the disks can handle,
160 * we probably want maxrun to be 1 block less so that we
161 * don't create a block larger than the device can handle.
162 */
163 *runp = 0;
164 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1;
165 }
166
167 xap = ap == NULL ? a : ap;
168 if (!nump)
169 nump = #
170 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0)
171 return (error);
172
173 num = *nump;
174 if (num == 0) {
175 *bnp = blkptrtodb(ump, letoh32(ip->i_e2fs_blocks[bn]));
176 if (*bnp == 0)
177 *bnp = -1;
178 else if (runp)
179 for (++bn; bn < NDADDR && *runp < maxrun &&
180 is_sequential(ump,
181 letoh32(ip->i_e2fs_blocks[bn - 1]),
182 letoh32(ip->i_e2fs_blocks[bn]));
183 ++bn, ++*runp)
184 /* nothing */;
185 return (0);
186 }
187
188
189 /* Get disk address out of indirect block array */
190 daddr = letoh32(ip->i_e2fs_blocks[NDADDR + xap->in_off]);
191
192 devvp = VFSTOUFS(vp->v_mount)->um_devvp;
193
194 #ifdef DIAGNOSTIC
195 if (num > NIADDR + 1 || num < 1) {
196 printf("ext2fs_bmaparray: num=%d\n", num);
197 panic("ext2fs_bmaparray: num");
198 }
199 #endif
200 for (bp = NULL, ++xap; --num; ++xap) {
201 /*
202 * Exit the loop if there is no disk address assigned yet and
203 * the indirect block isn't in the cache, or if we were
204 * looking for an indirect block and we've found it.
205 */
206
207 metalbn = xap->in_lbn;
208 if ((daddr == 0 && !incore(vp, metalbn)) || metalbn == bn)
209 break;
210 /*
211 * If we get here, we've either got the block in the cache
212 * or we have a disk address for it, go fetch it.
213 */
214 if (bp)
215 brelse(bp);
216
217 xap->in_exists = 1;
218 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, INFSLP);
219 if (bp->b_flags & (B_DONE | B_DELWRI)) {
220 ;
221 }
222 #ifdef DIAGNOSTIC
223 else if (!daddr)
224 panic("ext2fs_bmaparry: indirect block not in cache");
225 #endif
226 else {
227 bp->b_blkno = blkptrtodb(ump, daddr);
228 bp->b_flags |= B_READ;
229 VOP_STRATEGY(bp->b_vp, bp);
230 curproc->p_ru.ru_inblock++; /* XXX */
231 bcstats.pendingreads++;
232 if ((error = biowait(bp)) != 0) {
233 brelse(bp);
234 return (error);
235 }
236 }
237
238 daddr = letoh32(((int32_t *)bp->b_data)[xap->in_off]);
239 if (num == 1 && daddr && runp)
240 for (bn = xap->in_off + 1;
241 bn < MNINDIR(ump) && *runp < maxrun &&
242 is_sequential(ump, ((u_int32_t *)bp->b_data)[bn - 1],
243 ((u_int32_t *)bp->b_data)[bn]);
244 ++bn, ++*runp)
245 /* nothing */;
246 }
247 if (bp)
248 brelse(bp);
249
250 daddr = blkptrtodb(ump, daddr);
251 *bnp = daddr == 0 ? -1 : daddr;
252 return (0);
253 }
254