Line data Source code
1 : /* $OpenBSD: ext2fs_bmap.c,v 1.26 2015/03/14 03:38:52 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
69 0 : ext2fs_bmap(void *v)
70 : {
71 0 : 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 0 : if (ap->a_vpp != NULL)
78 0 : *ap->a_vpp = VTOI(ap->a_vp)->i_devvp;
79 0 : if (ap->a_bnp == NULL)
80 0 : return (0);
81 :
82 0 : if (VTOI(ap->a_vp)->i_e2din->e2di_flags & EXT4_EXTENTS) {
83 0 : return (ext4_bmapext(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL,
84 : ap->a_runp));
85 : }
86 0 : return (ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL, NULL,
87 : ap->a_runp));
88 0 : }
89 :
90 : /*
91 : * Logical block number of a file -> physical block number on disk within ext4 extents.
92 : */
93 : int
94 0 : 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 0 : struct ext4_extent_path path;
100 : daddr_t pos;
101 :
102 0 : ip = VTOI(vp);
103 0 : fs = ip->i_e2fs;
104 :
105 0 : if (runp != NULL)
106 0 : *runp = 0;
107 0 : if (nump != NULL)
108 0 : *nump = 0;
109 :
110 0 : ext4_ext_find_extent(fs, ip, bn, &path);
111 0 : if ((ep = path.ep_ext) == NULL)
112 0 : return (EIO);
113 :
114 0 : pos = bn - ep->e_blk + (((daddr_t)ep->e_start_hi << 32) | ep->e_start_lo);
115 0 : if ((*bnp = fsbtodb(fs, pos)) == 0)
116 0 : *bnp = -1;
117 0 : return (0);
118 0 : }
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
135 0 : 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 0 : struct indir a[NIADDR+1], *xap;
144 : int32_t daddr;
145 : long metalbn;
146 0 : int error, maxrun = 0, num;
147 :
148 0 : ip = VTOI(vp);
149 0 : mp = vp->v_mount;
150 0 : ump = VFSTOUFS(mp);
151 : #ifdef DIAGNOSTIC
152 0 : if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL))
153 0 : panic("ext2fs_bmaparray: invalid arguments");
154 : #endif
155 :
156 0 : 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 0 : *runp = 0;
164 0 : maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1;
165 0 : }
166 :
167 0 : xap = ap == NULL ? a : ap;
168 0 : if (!nump)
169 0 : nump = #
170 0 : if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0)
171 0 : return (error);
172 :
173 0 : num = *nump;
174 0 : if (num == 0) {
175 0 : *bnp = blkptrtodb(ump, letoh32(ip->i_e2fs_blocks[bn]));
176 0 : if (*bnp == 0)
177 0 : *bnp = -1;
178 0 : else if (runp)
179 0 : for (++bn; bn < NDADDR && *runp < maxrun &&
180 0 : is_sequential(ump,
181 : letoh32(ip->i_e2fs_blocks[bn - 1]),
182 : letoh32(ip->i_e2fs_blocks[bn]));
183 0 : ++bn, ++*runp)
184 : /* nothing */;
185 0 : return (0);
186 : }
187 :
188 :
189 : /* Get disk address out of indirect block array */
190 0 : daddr = letoh32(ip->i_e2fs_blocks[NDADDR + xap->in_off]);
191 :
192 0 : devvp = VFSTOUFS(vp->v_mount)->um_devvp;
193 :
194 : #ifdef DIAGNOSTIC
195 0 : if (num > NIADDR + 1 || num < 1) {
196 0 : printf("ext2fs_bmaparray: num=%d\n", num);
197 0 : panic("ext2fs_bmaparray: num");
198 : }
199 : #endif
200 0 : 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 0 : metalbn = xap->in_lbn;
208 0 : 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 0 : if (bp)
215 0 : brelse(bp);
216 :
217 0 : xap->in_exists = 1;
218 0 : bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0);
219 0 : if (bp->b_flags & (B_DONE | B_DELWRI)) {
220 : ;
221 : }
222 : #ifdef DIAGNOSTIC
223 0 : else if (!daddr)
224 0 : panic("ext2fs_bmaparry: indirect block not in cache");
225 : #endif
226 : else {
227 0 : bp->b_blkno = blkptrtodb(ump, daddr);
228 0 : bp->b_flags |= B_READ;
229 0 : VOP_STRATEGY(bp);
230 0 : curproc->p_ru.ru_inblock++; /* XXX */
231 0 : bcstats.pendingreads++;
232 0 : if ((error = biowait(bp)) != 0) {
233 0 : brelse(bp);
234 0 : return (error);
235 : }
236 : }
237 :
238 0 : daddr = letoh32(((int32_t *)bp->b_data)[xap->in_off]);
239 0 : if (num == 1 && daddr && runp)
240 0 : for (bn = xap->in_off + 1;
241 0 : bn < MNINDIR(ump) && *runp < maxrun &&
242 0 : is_sequential(ump, ((u_int32_t *)bp->b_data)[bn - 1],
243 : ((u_int32_t *)bp->b_data)[bn]);
244 0 : ++bn, ++*runp)
245 : /* nothing */;
246 : }
247 0 : if (bp)
248 0 : brelse(bp);
249 :
250 0 : daddr = blkptrtodb(ump, daddr);
251 0 : *bnp = daddr == 0 ? -1 : daddr;
252 0 : return (0);
253 0 : }
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