mtd: Check add_mtd_device() ret code

add_mtd_device() can fail. We should always check its return value
and gracefully handle the failure case. Fix the call sites where this
not done (in mtdpart.c) and add a __must_check attribute to the
prototype to avoid this kind of mistakes.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>

diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index 9887bda..b31c868 100644 (file)
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -7,7 +7,7 @@
 extern struct mutex mtd_table_mutex;
 
 struct mtd_info *__mtd_next_device(int i);
-int add_mtd_device(struct mtd_info *mtd);
+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 *);

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index b6af41b..60104e1 100644 (file)
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -618,10 +618,22 @@ int mtd_add_partition(struct mtd_info *parent, const char *name,
        list_add(&new->list, &mtd_partitions);
        mutex_unlock(&mtd_partitions_mutex);
 
-       add_mtd_device(&new->mtd);
+       ret = add_mtd_device(&new->mtd);
+       if (ret)
+               goto err_remove_part;
 
        mtd_add_partition_attrs(new);
 
+       return 0;
+
+err_remove_part:
+       mutex_lock(&mtd_partitions_mutex);
+       list_del(&new->list);
+       mutex_unlock(&mtd_partitions_mutex);
+
+       free_partition(new);
+       pr_info("%s:%i\n", __func__, __LINE__);
+
        return ret;
 }
 EXPORT_SYMBOL_GPL(mtd_add_partition);
@@ -712,22 +724,31 @@ int add_mtd_partitions(struct mtd_info *master,
 {
        struct mtd_part *slave;
        uint64_t cur_offset = 0;
-       int i;
+       int i, ret;
 
        printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 
        for (i = 0; i < nbparts; i++) {
                slave = allocate_partition(master, parts + i, i, cur_offset);
                if (IS_ERR(slave)) {
-                       del_mtd_partitions(master);
-                       return PTR_ERR(slave);
+                       ret = PTR_ERR(slave);
+                       goto err_del_partitions;
                }
 
                mutex_lock(&mtd_partitions_mutex);
                list_add(&slave->list, &mtd_partitions);
                mutex_unlock(&mtd_partitions_mutex);
 
-               add_mtd_device(&slave->mtd);
+               ret = add_mtd_device(&slave->mtd);
+               if (ret) {
+                       mutex_lock(&mtd_partitions_mutex);
+                       list_del(&slave->list);
+                       mutex_unlock(&mtd_partitions_mutex);
+
+                       free_partition(slave);
+                       goto err_del_partitions;
+               }
+
                mtd_add_partition_attrs(slave);
                /* Look for subpartitions */
                parse_mtd_partitions(&slave->mtd, parts[i].types, NULL);
@@ -736,6 +757,11 @@ int add_mtd_partitions(struct mtd_info *master,
        }
 
        return 0;
+
+err_del_partitions:
+       del_mtd_partitions(master);
+
+       return ret;
 }
 
 static DEFINE_SPINLOCK(part_parser_lock);