diff options
| -rw-r--r-- | drivers/mtd/mtdcore.c | 37 | ||||
| -rw-r--r-- | include/linux/mtd/mtd.h | 7 |
2 files changed, 37 insertions, 7 deletions
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 06ec9f836ae..f11f55f0241 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -214,12 +214,23 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) ret = NULL; } - if (ret && !try_module_get(ret->owner)) + if (!ret) + goto out_unlock; + + if (!try_module_get(ret->owner)) { + ret = NULL; + goto out_unlock; + } + + if (ret->get_device && ret->get_device(ret)) { + module_put(ret->owner); ret = NULL; + goto out_unlock; + } - if (ret) - ret->usecount++; + ret->usecount++; +out_unlock: mutex_unlock(&mtd_table_mutex); return ret; } @@ -235,8 +246,8 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) struct mtd_info *get_mtd_device_nm(const char *name) { - int i; - struct mtd_info *mtd = ERR_PTR(-ENODEV); + int i, err = -ENODEV; + struct mtd_info *mtd = NULL; mutex_lock(&mtd_table_mutex); @@ -247,17 +258,27 @@ struct mtd_info *get_mtd_device_nm(const char *name) } } - if (i == MAX_MTD_DEVICES) + if (!mtd) goto out_unlock; if (!try_module_get(mtd->owner)) goto out_unlock; + if (mtd->get_device) { + err = mtd->get_device(mtd); + if (err) + goto out_put; + } + mtd->usecount++; + mutex_unlock(&mtd_table_mutex); + return mtd; +out_put: + module_put(mtd->owner); out_unlock: mutex_unlock(&mtd_table_mutex); - return mtd; + return ERR_PTR(err); } void put_mtd_device(struct mtd_info *mtd) @@ -266,6 +287,8 @@ void put_mtd_device(struct mtd_info *mtd) mutex_lock(&mtd_table_mutex); c = --mtd->usecount; + if (mtd->put_device) + mtd->put_device(mtd); mutex_unlock(&mtd_table_mutex); BUG_ON(c < 0); diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 89e937dfef5..d644e57703a 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -207,6 +207,13 @@ struct mtd_info { struct module *owner; int usecount; + + /* If the driver is something smart, like UBI, it may need to maintain + * its own reference counting. The below functions are only for driver. + * The driver may register its callbacks. These callbacks are not + * supposed to be called by MTD users */ + int (*get_device) (struct mtd_info *mtd); + void (*put_device) (struct mtd_info *mtd); }; |