提交 3bd45657 编写于 作者: M Maxim Levitsky 提交者: David Woodhouse

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: NMaxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
上级 bb315f74
...@@ -463,27 +463,38 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) ...@@ -463,27 +463,38 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
ret = NULL; ret = NULL;
} }
if (!ret) if (!ret) {
goto out_unlock; ret = ERR_PTR(err);
goto out;
if (!try_module_get(ret->owner))
goto out_unlock;
if (ret->get_device) {
err = ret->get_device(ret);
if (err)
goto out_put;
} }
ret->usecount++; err = __get_mtd_device(ret);
if (err)
ret = ERR_PTR(err);
out:
mutex_unlock(&mtd_table_mutex); mutex_unlock(&mtd_table_mutex);
return ret; return ret;
}
out_put:
module_put(ret->owner); int __get_mtd_device(struct mtd_info *mtd)
out_unlock: {
mutex_unlock(&mtd_table_mutex); int err;
return ERR_PTR(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) ...@@ -534,14 +545,19 @@ struct mtd_info *get_mtd_device_nm(const char *name)
void put_mtd_device(struct mtd_info *mtd) void put_mtd_device(struct mtd_info *mtd)
{ {
int c;
mutex_lock(&mtd_table_mutex); 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) if (mtd->put_device)
mtd->put_device(mtd); mtd->put_device(mtd);
mutex_unlock(&mtd_table_mutex);
BUG_ON(c < 0);
module_put(mtd->owner); module_put(mtd->owner);
} }
...@@ -579,7 +595,9 @@ EXPORT_SYMBOL_GPL(add_mtd_device); ...@@ -579,7 +595,9 @@ EXPORT_SYMBOL_GPL(add_mtd_device);
EXPORT_SYMBOL_GPL(del_mtd_device); EXPORT_SYMBOL_GPL(del_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device); EXPORT_SYMBOL_GPL(get_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device_nm); 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(__put_mtd_device);
EXPORT_SYMBOL_GPL(register_mtd_user); EXPORT_SYMBOL_GPL(register_mtd_user);
EXPORT_SYMBOL_GPL(unregister_mtd_user); EXPORT_SYMBOL_GPL(unregister_mtd_user);
EXPORT_SYMBOL_GPL(default_mtd_writev); EXPORT_SYMBOL_GPL(default_mtd_writev);
......
...@@ -289,8 +289,9 @@ extern int add_mtd_device(struct mtd_info *mtd); ...@@ -289,8 +289,9 @@ extern int add_mtd_device(struct mtd_info *mtd);
extern int del_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 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 struct mtd_info *get_mtd_device_nm(const char *name);
extern void put_mtd_device(struct mtd_info *mtd); extern void put_mtd_device(struct mtd_info *mtd);
......
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