Release 4.7 drivers/md/dm-zero.c
/*
* Copyright (C) 2003 Jana Saout <jana@saout.de>
*
* This file is released under the GPL.
*/
#include <linux/device-mapper.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/bio.h>
#define DM_MSG_PREFIX "zero"
/*
* Construct a dummy mapping that only returns zeros
*/
static int zero_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
if (argc != 0) {
ti->error = "No arguments required";
return -EINVAL;
}
/*
* Silently drop discards, avoiding -EOPNOTSUPP.
*/
ti->num_discard_bios = 1;
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 42 | 87.50% | 3 | 75.00% |
| mike snitzer | mike snitzer | 6 | 12.50% | 1 | 25.00% |
| Total | 48 | 100.00% | 4 | 100.00% |
/*
* Return zeros only on reads
*/
static int zero_map(struct dm_target *ti, struct bio *bio)
{
switch(bio_rw(bio)) {
case READ:
zero_fill_bio(bio);
break;
case READA:
/* readahead of null bytes only wastes buffer cache */
return -EIO;
case WRITE:
/* writes get silently dropped */
break;
}
bio_endio(bio);
/* accepted bio, don't make new request */
return DM_MAPIO_SUBMITTED;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 55 | 98.21% | 1 | 50.00% |
| kiyoshi ueda | kiyoshi ueda | 1 | 1.79% | 1 | 50.00% |
| Total | 56 | 100.00% | 2 | 100.00% |
static struct target_type zero_target = {
.name = "zero",
.version = {1, 1, 0},
.module = THIS_MODULE,
.ctr = zero_ctr,
.map = zero_map,
};
static int __init dm_zero_init(void)
{
int r = dm_register_target(&zero_target);
if (r < 0)
DMERR("register failed %d", r);
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 34 | 100.00% | 3 | 100.00% |
| Total | 34 | 100.00% | 3 | 100.00% |
static void __exit dm_zero_exit(void)
{
dm_unregister_target(&zero_target);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 15 | 100.00% | 2 | 100.00% |
| Total | 15 | 100.00% | 2 | 100.00% |
module_init(dm_zero_init)
module_exit(dm_zero_exit)
MODULE_AUTHOR("Jana Saout <jana@saout.de>");
MODULE_DESCRIPTION(DM_NAME " dummy target returning zeros");
MODULE_LICENSE("GPL");
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 213 | 91.03% | 4 | 40.00% |
| kevin corry | kevin corry | 10 | 4.27% | 1 | 10.00% |
| mike snitzer | mike snitzer | 6 | 2.56% | 1 | 10.00% |
| jana saout | jana saout | 2 | 0.85% | 1 | 10.00% |
| mikulas patocka | mikulas patocka | 2 | 0.85% | 2 | 20.00% |
| kiyoshi ueda | kiyoshi ueda | 1 | 0.43% | 1 | 10.00% |
| Total | 234 | 100.00% | 10 | 100.00% |
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