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>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ed6e91c..fd1ac15 100644 (file)
--- 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;
        }