Introduce memory failure notifier, once hardware memory failure
occurs, after the kernel handles the corrupted page successfully,
someone who registered this chain gets noticed of the corrupted PFN.
Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
---
include/linux/mm.h | 2 ++
mm/memory-failure.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9f44254af8ce..665873c2788c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3197,6 +3197,8 @@ extern int sysctl_memory_failure_recovery;
extern void shake_page(struct page *p);
extern atomic_long_t num_poisoned_pages __read_mostly;
extern int soft_offline_page(unsigned long pfn, int flags);
+extern int register_memory_failure_notifier(struct notifier_block *nb);
+extern int unregister_memory_failure_notifier(struct notifier_block *nb);
#ifdef CONFIG_MEMORY_FAILURE
extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags);
#else
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 2d590cba412c..95c218bb0a37 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -68,6 +68,35 @@ int sysctl_memory_failure_recovery __read_mostly = 1;
atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
+static BLOCKING_NOTIFIER_HEAD(mf_notifier_list);
+
+/**
+ * register_memory_failure_notifier - Register function to be called if a
+ * corrupted page gets handled successfully
+ * @nb: Info about notifier function to be called
+ *
+ * Currently always returns zero, as blocking_notifier_chain_register()
+ * always returns zero.
+ */
+int register_memory_failure_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&mf_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_memory_failure_notifier);
+
+/**
+ * unregister_memory_failure_notifier - Unregister previously registered
+ * memory failure notifier
+ * @nb: Hook to be unregistered
+ *
+ * Returns zero on success, or %-ENOENT on failure.
+ */
+int unregister_memory_failure_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&mf_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_memory_failure_notifier);
+
static bool __page_handle_poison(struct page *page)
{
int ret;
@@ -1136,6 +1165,10 @@ static void action_result(unsigned long pfn, enum mf_action_page_type type,
num_poisoned_pages_inc();
pr_err("Memory failure: %#lx: recovery action for %s: %s\n",
pfn, action_page_types[type], action_name[result]);
+
+ /* notify the chain if we handle successfully only */
+ if (result == MF_RECOVERED)
+ blocking_notifier_call_chain(&mf_notifier_list, pfn, NULL);
}
static int page_action(struct page_state *ps, struct page *p,
--
2.20.1
