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dm_target_zero.c revision 1.2 
      1 /*        $NetBSD: dm_target_zero.c,v 1.2 2008/12/19 15:24:03 haad Exp $      */
      2 
      3 /*
      4  * Copyright (c) 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Adam Hamsik.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 
     33 /*
     34  * This file implements initial version of device-mapper zero target.
     35  */
     36 #include <sys/types.h>
     37 #include <sys/param.h>
     38 
     39 #include <sys/buf.h>
     40 
     41 #include "dm.h"
     42 
     43 /*
     44  * Zero target init function. This target doesn't need
     45  * target specific config area.
     46  */
     47 int
     48 dm_target_zero_init(dm_dev_t *dmv, void **target_config, char *argv)
     49 {
     50 
     51 	printf("Zero target init function called!!\n");
     52 
     53 	dmv->dev_type = DM_ZERO_DEV;
     54 
     55 	*target_config = NULL;
     56 
     57 	return 0;
     58 }
     59 
     60 /* Status routine called to get params string. */
     61 char *
     62 dm_target_zero_status(void *target_config)
     63 {
     64 	return NULL;
     65 }
     66 
     67 
     68 /*
     69  * This routine does IO operations.
     70  */
     71 int
     72 dm_target_zero_strategy(dm_table_entry_t *table_en, struct buf *bp)
     73 {
     74 
     75 	/* printf("Zero target read function called %d!!\n", bp->b_bcount); */
     76 
     77 	memset(bp->b_data, 0, bp->b_bcount);
     78 	bp->b_resid = 0; /* nestiobuf_done wants b_resid = 0 to be sure
     79 			    that there is no other io to done  */
     80 
     81 	biodone(bp);
     82 
     83 	return 0;
     84 }
     85 
     86 /* Doesn't not need to do anything here. */
     87 int
     88 dm_target_zero_destroy(dm_table_entry_t *table_en)
     89 {
     90 	table_en->target_config = NULL;
     91 
     92 	return 0;
     93 }
     94 
     95 /* Doesn't not need to do anything here. */
     96 int
     97 dm_target_zero_deps(dm_table_entry_t *table_en, prop_array_t prop_array)
     98 {
     99 	return 0;
    100 }
    101 
    102 /* Unsuported for this target. */
    103 int
    104 dm_target_zero_upcall(dm_table_entry_t *table_en, struct buf *bp)
    105 {
    106 	return 0;
    107 }
    108 
    109