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filecore_bmap.c revision 1.2
      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