[PATCH 1/4] bdi: add check for bdi_debug_root
From: weiping zhang <hidden>
Date: 2017-10-26 17:35:36
Also in:
linux-mm
Subsystem:
memory management, memory management - misc, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
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 <redacted> --- 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