diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index e00b12aa5ec9..6dbd596a1129 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -93,10 +93,33 @@ static void mtd_release(struct device *dev) struct mtd_info *mtd = dev_get_drvdata(dev); dev_t index = MTD_DEVT(mtd->index); + if (mtd_is_partition(mtd)) + release_mtd_partition(mtd); + /* remove /dev/mtdXro node */ device_destroy(&mtd_class, index + 1); } +static void mtd_device_release(struct kref *kref) +{ + struct mtd_info *mtd = container_of(kref, struct mtd_info, refcnt); + + debugfs_remove_recursive(mtd->dbg.dfs_dir); + + /* Try to remove the NVMEM provider */ + nvmem_unregister(mtd->nvmem); + + device_unregister(&mtd->dev); + + /* Clear dev so mtd can be safely re-registered later if desired */ + memset(&mtd->dev, 0, sizeof(mtd->dev)); + + idr_remove(&mtd_idr, mtd->index); + of_node_put(mtd_get_of_node(mtd)); + + module_put(THIS_MODULE); +} + #define MTD_DEVICE_ATTR_RO(name) \ static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL) @@ -666,7 +689,7 @@ int add_mtd_device(struct mtd_info *mtd) } mtd->index = i; - mtd->usecount = 0; + kref_init(&mtd->refcnt); /* default value if not set by driver */ if (mtd->bitflip_threshold == 0) @@ -779,7 +802,6 @@ int del_mtd_device(struct mtd_info *mtd) { int ret; struct mtd_notifier *not; - struct device_node *mtd_of_node; mutex_lock(&mtd_table_mutex); @@ -793,28 +815,8 @@ int del_mtd_device(struct mtd_info *mtd) list_for_each_entry(not, &mtd_notifiers, list) not->remove(mtd); - if (mtd->usecount) { - printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n", - mtd->index, mtd->name, mtd->usecount); - ret = -EBUSY; - } else { - mtd_of_node = mtd_get_of_node(mtd); - debugfs_remove_recursive(mtd->dbg.dfs_dir); - - /* Try to remove the NVMEM provider */ - nvmem_unregister(mtd->nvmem); - - device_unregister(&mtd->dev); - - /* Clear dev so mtd can be safely re-registered later if desired */ - memset(&mtd->dev, 0, sizeof(mtd->dev)); - - idr_remove(&mtd_idr, mtd->index); - of_node_put(mtd_of_node); - - module_put(THIS_MODULE); - ret = 0; - } + kref_put(&mtd->refcnt, mtd_device_release); + ret = 0; out_error: mutex_unlock(&mtd_table_mutex); @@ -1230,19 +1232,21 @@ int __get_mtd_device(struct mtd_info *mtd) if (!try_module_get(master->owner)) return -ENODEV; + kref_get(&mtd->refcnt); + if (master->_get_device) { err = master->_get_device(mtd); if (err) { + kref_put(&mtd->refcnt, mtd_device_release); module_put(master->owner); return err; } } - master->usecount++; - while (mtd->parent) { - mtd->usecount++; + if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd->parent != master) + kref_get(&mtd->parent->refcnt); mtd = mtd->parent; } @@ -1329,18 +1333,20 @@ void __put_mtd_device(struct mtd_info *mtd) { struct mtd_info *master = mtd_get_master(mtd); - while (mtd->parent) { - --mtd->usecount; - BUG_ON(mtd->usecount < 0); - mtd = mtd->parent; - } + while (mtd != master) { + struct mtd_info *parent = mtd->parent; - master->usecount--; + kref_put(&mtd->refcnt, mtd_device_release); + mtd = parent; + } if (master->_put_device) master->_put_device(master); module_put(master->owner); + + if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) + kref_put(&master->refcnt, mtd_device_release); } EXPORT_SYMBOL_GPL(__put_mtd_device); diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h index b5eefeabf310..b014861a06a6 100644 --- a/drivers/mtd/mtdcore.h +++ b/drivers/mtd/mtdcore.h @@ -12,6 +12,7 @@ int __must_check add_mtd_device(struct mtd_info *mtd); int del_mtd_device(struct mtd_info *mtd); int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int); int del_mtd_partitions(struct mtd_info *); +void release_mtd_partition(struct mtd_info *mtd); struct mtd_partitions; diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index a46affbb037d..23483db8f30c 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -32,6 +32,12 @@ static inline void free_partition(struct mtd_info *mtd) kfree(mtd); } +void release_mtd_partition(struct mtd_info *mtd) +{ + WARN_ON(!list_empty(&mtd->part.node)); + free_partition(mtd); +} + static struct mtd_info *allocate_partition(struct mtd_info *parent, const struct mtd_partition *part, int partno, uint64_t cur_offset) @@ -309,13 +315,11 @@ static int __mtd_del_partition(struct mtd_info *mtd) sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs); + list_del_init(&mtd->part.node); err = del_mtd_device(mtd); if (err) return err; - list_del(&mtd->part.node); - free_partition(mtd); - return 0; } @@ -333,6 +337,7 @@ static int __del_mtd_partitions(struct mtd_info *mtd) __del_mtd_partitions(child); pr_info("Deleting %s MTD partition\n", child->name); + list_del_init(&child->part.node); ret = del_mtd_device(child); if (ret < 0) { pr_err("Error when deleting partition \"%s\" (%d)\n", @@ -340,9 +345,6 @@ static int __del_mtd_partitions(struct mtd_info *mtd) err = ret; continue; } - - list_del(&child->part.node); - free_partition(child); } return err; diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 7c58c44662b8..914a9f974baa 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -379,7 +379,7 @@ struct mtd_info { struct module *owner; struct device dev; - int usecount; + struct kref refcnt; struct mtd_debug_info dbg; struct nvmem_device *nvmem; struct nvmem_device *otp_user_nvmem;