HWPOISON: make semantics of IGNORED/DELAYED clear

Change semantics for
- IGNORED: not handled; it may well be _unsafe_
- DELAYED: to be handled later; it is _safe_

With this change,
- IGNORED/FAILED mean (maybe) Error
- DELAYED/RECOVERED mean Success

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 7 insertions, 15 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ed6e91c87a5..fd1ac1537f0 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -336,16 +336,16 @@ static void collect_procs(struct page *page, struct list_head *tokill)
  */
 
 enum outcome {
-        FAILED,         /* Error handling failed */
+        IGNORED,        /* Error: cannot be handled */
+        FAILED,         /* Error: handling failed */
         DELAYED,        /* Will be handled later */
-        IGNORED,        /* Error safely ignored */
         RECOVERED,      /* Successfully recovered */
 };
 
 static const char *action_name[] = {
+        [IGNORED] = "Ignored",
         [FAILED] = "Failed",
         [DELAYED] = "Delayed",
-        [IGNORED] = "Ignored",
         [RECOVERED] = "Recovered",
 };
 
@@ -380,14 +380,6 @@ static int delete_from_lru_cache(struct page *p)
  */
 static int me_kernel(struct page *p, unsigned long pfn)
 {
-        return DELAYED;
-}
-
-/*
- * Already poisoned page.
- */
-static int me_ignore(struct page *p, unsigned long pfn)
-{
         return IGNORED;
 }
 
@@ -604,7 +596,7 @@ static struct page_state {
         char *msg;
         int (*action)(struct page *p, unsigned long pfn);
 } error_states[] = {
-        { reserved,     reserved,       "reserved kernel",      me_ignore },
+        { reserved,     reserved,       "reserved kernel",      me_kernel },
         /*
          * free pages are specially detected outside this table:
          * PG_buddy pages only make a small fraction of all free pages.
@@ -788,7 +780,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
 
         p = pfn_to_page(pfn);
         if (TestSetPageHWPoison(p)) {
-                action_result(pfn, "already hardware poisoned", IGNORED);
+                printk(KERN_ERR "MCE %#lx: already hardware poisoned\n", pfn);
                 return 0;
         }
 
@@ -843,7 +835,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
          * unpoison always clear PG_hwpoison inside page lock
          */
         if (!PageHWPoison(p)) {
-                action_result(pfn, "unpoisoned", IGNORED);
+                printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
                 res = 0;
                 goto out;
         }
@@ -865,7 +857,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
          */
         if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
                 action_result(pfn, "already truncated LRU", IGNORED);
-                res = 0;
+                res = -EBUSY;
                 goto out;
         }