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: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

2 files changed, 41 insertions, 22 deletions

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index b3b98d1fffc3..67669a76eaf5 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -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 @@ out_unlock:
 
 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);
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index ba53ecca107c..11d8e68d17c0 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -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);