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dm_target_linear.c revision 1.1.2.2 
      1 /*
      2  * Copyright (c) 1996, 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to The NetBSD Foundation
      6  * by Adam Hamsik.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     27  * POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 
     31 /*
     32  * This file implements initial version of device-mapper dklinear target.
     33  */
     34 
     35 #include <sys/types.h>
     36 #include <sys/param.h>
     37 
     38 #include <sys/buf.h>
     39 #include <sys/disk.h>
     40 #include <sys/errno.h>
     41 #include <sys/ioctl.h>
     42 #include <sys/ioccom.h>
     43 #include <sys/kmem.h>
     44 #include <sys/types.h>
     45 #include <sys/param.h>
     46 #include <sys/queue.h>
     47 #include <sys/vnode.h>
     48 
     49 #include "dm.h"
     50 
     51 static uint64_t atoi(const char *);
     52 
     53 /*
     54  * Allocate target specific config data, and link them to table.
     55  * argv[0] is name,
     56  * argv[1] is physical data offset.
     57  */
     58 int
     59 dm_target_linear_init(struct dm_dev *dmv, void **target_config,
     60 		int argc, const char **argv)
     61 {
     62 	struct target_linear_config *tlc;
     63 	struct dm_pdev *dmp;
     64 
     65 	printf("Linear target init function called %s--%s!!\n",
     66 	    argv[0], argv[1]);
     67 
     68 	dmp = dm_pdev_lookup_name(argv[0]);
     69 
     70 	if ((tlc = kmem_alloc(sizeof(struct target_linear_config), KM_NOSLEEP))
     71 	    == NULL)
     72 		return 1;
     73 
     74 	/* XXX howto convert char* to number ? tlc->offset = atoi(argv[1]); */
     75 
     76 	tlc->pdev = dmp;
     77 	tlc->offset = 0; 	/* default settings */
     78 
     79 	/* Check user input if it is not leave offset as 0. */
     80 	if (isdigit((int)argv[1]))
     81 		tlc->offset = atoi(argv[1]);
     82 
     83 	*target_config = tlc;
     84 
     85 	return 0;
     86 }
     87 
     88 /*
     89  * Do IO operation, called from dmstrategy routine.
     90  */
     91 int
     92 dm_target_linear_strategy(struct dm_table_entry *table_en, struct buf *bp)
     93 {
     94 	struct target_linear_config *tlc;
     95 
     96 	tlc = table_en->target_config;
     97 
     98 	printf("Linear target read function called!!\n");
     99 
    100 	bp->b_blkno += tlc->offset;
    101 
    102 	VOP_STRATEGY(tlc->pdev->pdev_vnode, bp);
    103 
    104 	return 0;
    105 
    106 }
    107 
    108 /*
    109  * Destroy target specific data.
    110  */
    111 int
    112 dm_target_linear_destroy(struct dm_table_entry *table_en)
    113 {
    114 
    115 	kmem_free(table_en->target_config, sizeof(struct target_linear_config));
    116 
    117 	return 0;
    118 }
    119 
    120 /*
    121  * Register upcall device.
    122  * Linear target doesn't need any upcall devices but other targets like
    123  * mirror, snapshot, multipath, stripe will use this functionality.
    124  */
    125 int
    126 dm_target_linear_upcall(struct dm_table_entry *table_en, struct buf *bp)
    127 {
    128 
    129 	return 0;
    130 }
    131 
    132 /*
    133  * Transform char s to uint64_t offset number.
    134  */
    135 static uint64_t
    136 atoi(const char *s)
    137 {
    138 	uint64_t n;
    139 
    140 	n = 0;
    141 
    142 	while (*s != '\0') {
    143 
    144 		if (!isdigit(*s))
    145 			break;
    146 
    147 		n = (10 * n) + (*s - '0');
    148 		s++;
    149 	}
    150 
    151 	return n;
    152 }
    153