Annotation of sys/ufs/ext2fs/ext2fs_bmap.c, Revision 1.1.1.1
1.1 nbrk 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: }
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