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filecore_bmap.c revision 1.6.22.2
      1 /*	$NetBSD: filecore_bmap.c,v 1.6.22.2 2009/05/04 08:13:42 yamt 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 1.6.22.2 2009/05/04 08:13:42 yamt 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 #include <sys/kauth.h>
     79 
     80 #include <fs/filecorefs/filecore.h>
     81 #include <fs/filecorefs/filecore_extern.h>
     82 #include <fs/filecorefs/filecore_node.h>
     83 
     84 /*
     85  * Bmap converts a the logical block number of a file to its physical block
     86  * number on the disk. The conversion is done by using the logical block
     87  * number to index into the data block (extent) for the file.
     88  */
     89 int
     90 filecore_bmap(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(struct filecore_mnt *fcmp, u_int32_t addr, daddr_t lbn, daddr_t *bnp)
    136 {
    137 	struct buf *bp;
    138 	u_long frag, sect, zone, izone, a, b, m, n;
    139 	u_int64_t zaddr;
    140 	u_long *ptr;
    141 	long c;
    142 	int error = 0;
    143 
    144 #ifdef FILECORE_DEBUG
    145 	printf("filecore_map(addr=%x, lbn=%llx)\n", addr, (long long)lbn);
    146 #endif
    147 	frag = addr >> 8;
    148 	sect = (addr & 0xff) +
    149 		((lbn << fcmp->log2bsize) >> fcmp->drec.log2secsize);
    150 	if (frag != 2)
    151 		zone = frag / fcmp->idspz;
    152 	else
    153 		zone = fcmp->drec.nzones / 2;
    154 	izone = zone;
    155 	if (zone != 0)
    156 		zaddr=((8<<fcmp->drec.log2secsize)-fcmp->drec.zone_spare)*zone
    157 		  - 8*FILECORE_DISCREC_SIZE;
    158 	else
    159 		zaddr = 0;
    160 	if (sect > 0)
    161 		sect--;
    162 	sect <<= fcmp->drec.share_size;
    163 	do {
    164 		error=bread(fcmp->fc_devvp, fcmp->map + zone,
    165 			    1 << fcmp->drec.log2secsize, NOCRED, 0, &bp);
    166 #ifdef FILECORE_DEBUG_BR
    167 		printf("bread(%p, %lx, %d, CRED, %p)=%d\n", fcmp->fc_devvp,
    168 		       fcmp->map+zone, 1 << fcmp->drec.log2secsize, bp, error);
    169 		printf("block is at %p\n", bp->b_data);
    170 #endif
    171 		if (error != 0) {
    172 #ifdef FILECORE_DEBUG_BR
    173 			printf("brelse(%p) bm1\n", bp);
    174 #endif
    175 			brelse(bp, 0);
    176 			return error;
    177 		}
    178 		ptr = (u_long *)(bp->b_data) + 1; /* skip map zone header */
    179 		if (zone == 0)
    180 			ptr += FILECORE_DISCREC_SIZE >> 2;
    181 		b = 0;
    182 		while (b < (8 << (fcmp->drec.log2secsize))
    183 		   - fcmp->drec.zone_spare) {
    184 			a = ptr[b >> 5] >> (b & 31);
    185 			c = 32 - (b & 31) - fcmp->drec.idlen;
    186 			if (c <= 0) {
    187 				m = ptr[(b >> 5) + 1];
    188 				a |= m << (fcmp->drec.idlen+c);
    189 				m >>= -c;
    190 				c += 32;
    191 			} else
    192 				m = a >> fcmp->drec.idlen;
    193 			n = fcmp->drec.idlen + 1;
    194 			while ((m & 1) == 0) {
    195 				m >>= 1;
    196 				n++;
    197 				if (--c == 0) {
    198 					c=32;
    199 					m = ptr[(b + n - 1) >> 5];
    200 				}
    201 			}
    202 			a &= fcmp->mask;
    203 			if (a == frag) {
    204 				if (sect << fcmp->drec.log2secsize < n
    205 				    << fcmp->drec.log2bpmb) {
    206 					*bnp = (((zaddr+b)
    207 					    << fcmp->drec.log2bpmb)
    208 					    >> fcmp->drec.log2secsize) + sect;
    209 
    210 #ifdef FILECORE_DEBUG_BR
    211 					printf("brelse(%p) bm2\n", bp);
    212 #endif
    213 					brelse(bp, 0);
    214 					return 0;
    215 				} else
    216 					sect -= (n<<fcmp->drec.log2bpmb)
    217 					    >> fcmp->drec.log2secsize;
    218 			}
    219 			b += n;
    220 		}
    221 #ifdef FILECORE_DEBUG_BR
    222 		printf("brelse(%p) bm3\n", bp);
    223 #endif
    224 		brelse(bp, 0);
    225 		if (++zone == fcmp->drec.nzones) {
    226 			zone = 0;
    227 			zaddr=0;
    228 		} else
    229 			zaddr += ((8 << fcmp->drec.log2secsize)
    230 			    - fcmp->drec.zone_spare);
    231 	} while (zone != izone);
    232 	return (E2BIG);
    233 }
    234 
    235 int
    236 filecore_bread(struct filecore_mnt *fcmp, u_int32_t addr, int size, kauth_cred_t cred, struct buf **bp)
    237 {
    238 	int error = 0;
    239 	daddr_t bn;
    240 
    241 	error = filecore_map(fcmp, addr, 0, &bn);
    242 	if (error) {
    243 
    244 #ifdef FILECORE_DEBUG
    245 		printf("filecore_bread(error=%d)\n", error);
    246 #endif
    247 		return error;
    248 	}
    249 	error = bread(fcmp->fc_devvp, bn, size, cred, 0, bp);
    250 #ifdef FILECORE_DEBUG_BR
    251 	printf("bread(%p, %llx, %d, CRED, %p)=%d\n", fcmp->fc_devvp,
    252 	    (long long)bn, size, *bp, error);
    253 #endif
    254 	return error;
    255 }
    256 
    257 int
    258 filecore_dbread(struct filecore_node *ip, struct buf **bp)
    259 {
    260 	int error = 0;
    261 
    262 	if (ip->i_block == -1)
    263 		error = filecore_map(ip->i_mnt, ip->i_dirent.addr,
    264 			0, &(ip->i_block));
    265 	if (error)
    266 		return error;
    267 	error = bread(ip->i_mnt->fc_devvp, ip->i_block, FILECORE_DIR_SIZE,
    268 		      NOCRED, 0, bp);
    269 #ifdef FILECORE_DEBUG_BR
    270 	printf("bread(%p, %llx, %d, CRED, %p)=%d\n", ip->i_mnt->fc_devvp,
    271 	       (long long)ip->i_block, FILECORE_DIR_SIZE, *bp, error);
    272 #endif
    273 	return error;
    274 }
    275