this patch add a check for bdi_debug_root and do error handle for it.
we should make sure it was created success, otherwise when add new
block device's bdi folder(eg, 8:0) will be create a debugfs root directory.
Signed-off-by: weiping zhang <zhangweiping@xxxxxxxxxxxxxxx>
---
mm/backing-dev.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 74b52dfd5852..5072be19d9b2 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -36,9 +36,12 @@ struct workqueue_struct *bdi_wq;
static struct dentry *bdi_debug_root;
-static void bdi_debug_init(void)
+static int bdi_debug_init(void)
{
bdi_debug_root = debugfs_create_dir("bdi", NULL);
+ if (!bdi_debug_root)
+ return -ENOMEM;
+ return 0;
}
static int bdi_debug_stats_show(struct seq_file *m, void *v)
@@ -126,8 +129,9 @@ static void bdi_debug_unregister(struct backing_dev_info *bdi)
debugfs_remove(bdi->debug_dir);
}
#else
-static inline void bdi_debug_init(void)
+static inline int bdi_debug_init(void)
{
+ return 0;
}
static inline void bdi_debug_register(struct backing_dev_info *bdi,
const char *name)
@@ -229,12 +233,19 @@ ATTRIBUTE_GROUPS(bdi_dev);
static __init int bdi_class_init(void)
{
+ int ret;
+
bdi_class = class_create(THIS_MODULE, "bdi");
if (IS_ERR(bdi_class))
return PTR_ERR(bdi_class);
bdi_class->dev_groups = bdi_dev_groups;
- bdi_debug_init();
+ ret = bdi_debug_init();
+ if (ret) {
+ class_destroy(bdi_class);
+ bdi_class = NULL;
+ return ret;
+ }
return 0;
}
--
2.14.2
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