xref: /netbsd-src/sys/fs/filecorefs/filecore_bmap.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: filecore_bmap.c,v 1.2 2003/08/07 16:31:37 agc Exp $	*/
2 
3 /*-
4  * Copyright (c) 1994 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	filecore_bmap.c		1.1	1998/6/26
32  */
33 
34 /*-
35  * Copyright (c) 1998 Andrew McMurry
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Berkeley and its contributors.
49  * 4. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  *	filecore_bmap.c		1.1	1998/6/26
66  */
67 
68 #include <sys/cdefs.h>
69 __KERNEL_RCSID(0, "$NetBSD: filecore_bmap.c,v 1.2 2003/08/07 16:31:37 agc Exp $");
70 
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/namei.h>
74 #include <sys/buf.h>
75 #include <sys/file.h>
76 #include <sys/vnode.h>
77 #include <sys/mount.h>
78 
79 #include <fs/filecorefs/filecore.h>
80 #include <fs/filecorefs/filecore_extern.h>
81 #include <fs/filecorefs/filecore_node.h>
82 
83 /*
84  * Bmap converts a the logical block number of a file to its physical block
85  * number on the disk. The conversion is done by using the logical block
86  * number to index into the data block (extent) for the file.
87  */
88 int
89 filecore_bmap(v)
90 	void *v;
91 {
92 	struct vop_bmap_args /* {
93 		struct vnode *a_vp;
94 		daddr_t a_bn;
95 		struct vnode **a_vpp;
96 		daddr_t *a_bnp;
97 		int *a_runp;
98 	} */ *ap = v;
99 	struct filecore_node *ip = VTOI(ap->a_vp);
100 	struct filecore_mnt *fcmp = ip->i_mnt;
101 	daddr_t lbn = ap->a_bn;
102 
103 	/*
104 	 * Check for underlying vnode requests and ensure that logical
105 	 * to physical mapping is requested.
106 	 */
107 	if (ap->a_vpp != NULL)
108 		*ap->a_vpp = ip->i_devvp;
109 	if (ap->a_bnp == NULL)
110 		return (0);
111 
112 	/*
113 	 * Determine maximum number of readahead blocks following the
114 	 * requested block.
115 	 */
116 	if (ap->a_runp) {
117 		int nblk;
118 		int bshift=fcmp->log2bsize;
119 
120 		nblk = (ip->i_size >> bshift) - (lbn + 1);
121 		if (nblk <= 0)
122 			*ap->a_runp = 0;
123 		else if (nblk >= (MAXBSIZE >> bshift))
124 			*ap->a_runp = (MAXBSIZE >> bshift) - 1;
125 		else
126 			*ap->a_runp = nblk;
127 	}
128 	/*
129 	 * Compute the requested block number
130 	 */
131 	return filecore_map(fcmp, ip->i_dirent.addr, lbn, ap->a_bnp);
132 }
133 
134 int
135 filecore_map(fcmp, addr, lbn, bnp)
136 	struct filecore_mnt *fcmp;
137 	u_int32_t addr;
138 	daddr_t lbn;
139 	daddr_t *bnp;
140 {
141 	struct buf *bp;
142 	u_long frag, sect, zone, izone, a, b, m, n;
143 	u_int64_t zaddr;
144 	u_long *ptr;
145 	long c;
146 	int error = 0;
147 
148 #ifdef FILECORE_DEBUG
149 	printf("filecore_map(addr=%x, lbn=%x)\n", addr, lbn);
150 #endif
151 	frag = addr >> 8;
152 	sect = (addr & 0xff) +
153 		((lbn << fcmp->log2bsize) >> fcmp->drec.log2secsize);
154 	if (frag != 2)
155 		zone = frag / fcmp->idspz;
156 	else
157 		zone = fcmp->drec.nzones / 2;
158 	izone = zone;
159 	if (zone != 0)
160 		zaddr=((8<<fcmp->drec.log2secsize)-fcmp->drec.zone_spare)*zone
161 		  - 8*FILECORE_DISCREC_SIZE;
162 	else
163 		zaddr = 0;
164 	if (sect > 0)
165 		sect--;
166 	sect <<= fcmp->drec.share_size;
167 	do {
168 		error=bread(fcmp->fc_devvp, fcmp->map + zone,
169 			    1 << fcmp->drec.log2secsize, NOCRED, &bp);
170 #ifdef FILECORE_DEBUG_BR
171 		printf("bread(%p, %lx, %d, CRED, %p)=%d\n", fcmp->fc_devvp,
172 		       fcmp->map+zone, 1 << fcmp->drec.log2secsize, bp, error);
173 		printf("block is at %p\n", bp->b_data);
174 #endif
175 		if (error != 0) {
176 #ifdef FILECORE_DEBUG_BR
177 			printf("brelse(%p) bm1\n", bp);
178 #endif
179 			brelse(bp);
180 			return error;
181 		}
182 		ptr = (u_long *)(bp->b_data) + 1; /* skip map zone header */
183 		if (zone == 0)
184 			ptr += FILECORE_DISCREC_SIZE >> 2;
185 		b = 0;
186 		while (b < (8 << (fcmp->drec.log2secsize))
187 		   - fcmp->drec.zone_spare) {
188 			a = ptr[b >> 5] >> (b & 31);
189 			c = 32 - (b & 31) - fcmp->drec.idlen;
190 			if (c <= 0) {
191 				m = ptr[(b >> 5) + 1];
192 				a |= m << (fcmp->drec.idlen+c);
193 				m >>= -c;
194 				c += 32;
195 			} else
196 				m = a >> fcmp->drec.idlen;
197 			n = fcmp->drec.idlen + 1;
198 			while ((m & 1) == 0) {
199 				m >>= 1;
200 				n++;
201 				if (--c == 0) {
202 					c=32;
203 					m = ptr[(b + n - 1) >> 5];
204 				}
205 			}
206 			a &= fcmp->mask;
207 			if (a == frag) {
208 				if (sect << fcmp->drec.log2secsize < n
209 				    << fcmp->drec.log2bpmb) {
210 					*bnp = (((zaddr+b)
211 					    << fcmp->drec.log2bpmb)
212 					    >> fcmp->drec.log2secsize) + sect;
213 
214 #ifdef FILECORE_DEBUG_BR
215 					printf("brelse(%p) bm2\n", bp);
216 #endif
217 					brelse(bp);
218 					return 0;
219 				} else
220 					sect -= (n<<fcmp->drec.log2bpmb)
221 					    >> fcmp->drec.log2secsize;
222 			}
223 			b += n;
224 		}
225 #ifdef FILECORE_DEBUG_BR
226 		printf("brelse(%p) bm3\n", bp);
227 #endif
228 		brelse(bp);
229 		if (++zone == fcmp->drec.nzones) {
230 			zone = 0;
231 			zaddr=0;
232 		} else
233 			zaddr += ((8 << fcmp->drec.log2secsize)
234 			    - fcmp->drec.zone_spare);
235 	} while (zone != izone);
236 	return (E2BIG);
237 }
238 
239 int
240 filecore_bread(fcmp, addr, size, cred, bp)
241 	struct filecore_mnt *fcmp;
242 	u_int32_t addr;
243 	int size;
244 	struct ucred *cred;
245 	struct buf **bp;
246 {
247 	int error = 0;
248 	daddr_t bn;
249 
250 	error = filecore_map(fcmp, addr, 0, &bn);
251 	if (error) {
252 
253 #ifdef FILECORE_DEBUG
254 		printf("filecore_bread(error=%d)\n", error);
255 #endif
256 		return error;
257 	}
258 	error = bread(fcmp->fc_devvp, bn, size, cred, bp);
259 #ifdef FILECORE_DEBUG_BR
260 	printf("bread(%p, %x, %d, CRED, %p)=%d\n", fcmp->fc_devvp, bn, size,
261 	       *bp, error);
262 #endif
263 	return error;
264 }
265 
266 int
267 filecore_dbread(ip, bp)
268 	struct filecore_node *ip;
269 	struct buf **bp;
270 {
271 	int error = 0;
272 
273 	if (ip->i_block == -1)
274 		error = filecore_map(ip->i_mnt, ip->i_dirent.addr,
275 			0, &(ip->i_block));
276 	if (error)
277 		return error;
278 	error = bread(ip->i_mnt->fc_devvp, ip->i_block, FILECORE_DIR_SIZE,
279 		      NOCRED, bp);
280 #ifdef FILECORE_DEBUG_BR
281 	printf("bread(%p, %x, %d, CRED, %p)=%d\n", ip->i_mnt->fc_devvp,
282 	       ip->i_block, FILECORE_DIR_SIZE, *bp, error);
283 #endif
284 	return error;
285 }
286