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Revision e2f455927b42767ecea5a4eb9bb740686e74c18b authored by Mark Brown on 27 February 2014, 11:26:07 UTC, committed by Mark Brown on 27 February 2014, 11:26:07 UTC 
Merge tag 'asoc-v3.14-rc3' into asoc-linus
 
ASoC: Fixes for v3.14

A few fixes, all driver speccific ones.  The DaVinci ones aren't as
clear as they should be from the subject lines on the commits but they
fix issues which will prevent correct operation in some use cases and
only affect that particular driver so are reasonably safe.

# gpg: Signature made Wed 19 Feb 2014 13:23:13 KST using RSA key ID 7EA229BD
# gpg: Good signature from "Mark Brown <broonie@sirena.org.uk>"
# gpg:                 aka "Mark Brown <broonie@debian.org>"
# gpg:                 aka "Mark Brown <broonie@kernel.org>"
# gpg:                 aka "Mark Brown <broonie@tardis.ed.ac.uk>"
# gpg:                 aka "Mark Brown <broonie@linaro.org>"
# gpg:                 aka "Mark Brown <Mark.Brown@linaro.org>"
2 parent s 6d0abec + 895be5b
Raw File
dm-target.c 
/*
 * Copyright (C) 2001 Sistina Software (UK) Limited
 *
 * This file is released under the GPL.
 */

#include "dm.h"

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/bio.h>

#define DM_MSG_PREFIX "target"

static LIST_HEAD(_targets);
static DECLARE_RWSEM(_lock);

#define DM_MOD_NAME_SIZE 32

static inline struct target_type *__find_target_type(const char *name)
{
	struct target_type *tt;

	list_for_each_entry(tt, &_targets, list)
		if (!strcmp(name, tt->name))
			return tt;

	return NULL;
}

static struct target_type *get_target_type(const char *name)
{
	struct target_type *tt;

	down_read(&_lock);

	tt = __find_target_type(name);
	if (tt && !try_module_get(tt->module))
		tt = NULL;

	up_read(&_lock);
	return tt;
}

static void load_module(const char *name)
{
	request_module("dm-%s", name);
}

struct target_type *dm_get_target_type(const char *name)
{
	struct target_type *tt = get_target_type(name);

	if (!tt) {
		load_module(name);
		tt = get_target_type(name);
	}

	return tt;
}

void dm_put_target_type(struct target_type *tt)
{
	down_read(&_lock);
	module_put(tt->module);
	up_read(&_lock);
}

int dm_target_iterate(void (*iter_func)(struct target_type *tt,
					void *param), void *param)
{
	struct target_type *tt;

	down_read(&_lock);
	list_for_each_entry(tt, &_targets, list)
		iter_func(tt, param);
	up_read(&_lock);

	return 0;
}

int dm_register_target(struct target_type *tt)
{
	int rv = 0;

	down_write(&_lock);
	if (__find_target_type(tt->name))
		rv = -EEXIST;
	else
		list_add(&tt->list, &_targets);

	up_write(&_lock);
	return rv;
}

void dm_unregister_target(struct target_type *tt)
{
	down_write(&_lock);
	if (!__find_target_type(tt->name)) {
		DMCRIT("Unregistering unrecognised target: %s", tt->name);
		BUG();
	}

	list_del(&tt->list);

	up_write(&_lock);
}

/*
 * io-err: always fails an io, useful for bringing
 * up LVs that have holes in them.
 */
static int io_err_ctr(struct dm_target *tt, unsigned int argc, char **args)
{
	/*
	 * Return error for discards instead of -EOPNOTSUPP
	 */
	tt->num_discard_bios = 1;

	return 0;
}

static void io_err_dtr(struct dm_target *tt)
{
	/* empty */
}

static int io_err_map(struct dm_target *tt, struct bio *bio)
{
	return -EIO;
}

static int io_err_map_rq(struct dm_target *ti, struct request *clone,
			 union map_info *map_context)
{
	return -EIO;
}

static struct target_type error_target = {
	.name = "error",
	.version = {1, 2, 0},
	.ctr  = io_err_ctr,
	.dtr  = io_err_dtr,
	.map  = io_err_map,
	.map_rq = io_err_map_rq,
};

int __init dm_target_init(void)
{
	return dm_register_target(&error_target);
}

void dm_target_exit(void)
{
	dm_unregister_target(&error_target);
}

EXPORT_SYMBOL(dm_register_target);
EXPORT_SYMBOL(dm_unregister_target);
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