Commit 3bd45657 authored by Maxim Levitsky's avatar Maxim Levitsky Committed by David Woodhouse
Browse files

mtd: create unlocked versions of {get,put}_mtd_device 



Use these only if you know that you already hold mtd_table_mutex

Signed-off-by: default avatarMaxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent bb315f74

drivers/mtd/mtdcore.c

+39 −21
Original line number Diff line number Diff line
@@ -463,27 +463,38 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) 
			ret = NULL;

	}



	if (!ret)

		goto out_unlock;



	if (!try_module_get(ret->owner))

		goto out_unlock;



	if (ret->get_device) {

		err = ret->get_device(ret);

		if (err)

			goto out_put;

	if (!ret) {

		ret = ERR_PTR(err);

		goto out;

	}



	ret->usecount++;

	err = __get_mtd_device(ret);

	if (err)

		ret = ERR_PTR(err);

out:

	mutex_unlock(&mtd_table_mutex);

	return ret;

}



out_put:

	module_put(ret->owner);

out_unlock:

	mutex_unlock(&mtd_table_mutex);

	return ERR_PTR(err);



int __get_mtd_device(struct mtd_info *mtd)

{

	int err;



	if (!try_module_get(mtd->owner))

		return -ENODEV;



	if (mtd->get_device) {



		err = mtd->get_device(mtd);



		if (err) {

			module_put(mtd->owner);

			return err;

		}

	}

	mtd->usecount++;

	return 0;

}



/**
@@ -534,14 +545,19 @@ struct mtd_info *get_mtd_device_nm(const char *name) 


void put_mtd_device(struct mtd_info *mtd)

{

	int c;



	mutex_lock(&mtd_table_mutex);

	c = --mtd->usecount;

	__put_mtd_device(mtd);

	mutex_unlock(&mtd_table_mutex);



}



void __put_mtd_device(struct mtd_info *mtd)

{

	--mtd->usecount;

	BUG_ON(mtd->usecount < 0);



	if (mtd->put_device)

		mtd->put_device(mtd);

	mutex_unlock(&mtd_table_mutex);

	BUG_ON(c < 0);



	module_put(mtd->owner);

}
@@ -579,7 +595,9 @@ EXPORT_SYMBOL_GPL(add_mtd_device); 
EXPORT_SYMBOL_GPL(del_mtd_device);

EXPORT_SYMBOL_GPL(get_mtd_device);

EXPORT_SYMBOL_GPL(get_mtd_device_nm);

EXPORT_SYMBOL_GPL(__get_mtd_device);

EXPORT_SYMBOL_GPL(put_mtd_device);

EXPORT_SYMBOL_GPL(__put_mtd_device);

EXPORT_SYMBOL_GPL(register_mtd_user);

EXPORT_SYMBOL_GPL(unregister_mtd_user);

EXPORT_SYMBOL_GPL(default_mtd_writev);

include/linux/mtd/mtd.h

+2 −1
Original line number Diff line number Diff line
@@ -289,8 +289,9 @@ extern int add_mtd_device(struct mtd_info *mtd); 
extern int del_mtd_device (struct mtd_info *mtd);



extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);

extern int __get_mtd_device(struct mtd_info *mtd);

extern void __put_mtd_device(struct mtd_info *mtd);

extern struct mtd_info *get_mtd_device_nm(const char *name);



extern void put_mtd_device(struct mtd_info *mtd);