Merge tag 'v4.13-rc1' into fixes

The fixes branch is based off a random pre-rc1 commit, because we had
some fixes that needed to go in before rc1 was released.

However we now need to fix some code that went in after that point, but
before rc1, so merge rc1 to get that code into fixes so we can fix it!

1 files changed, 153 insertions, 179 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index dbe3e50c9aa5..1cd3b3569af8 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -49,7 +49,6 @@
 #include <linux/swap.h>
 #include <linux/backing-dev.h>
 #include <linux/migrate.h>
-#include <linux/page-isolation.h>
 #include <linux/suspend.h>
 #include <linux/slab.h>
 #include <linux/swapops.h>
@@ -555,6 +554,39 @@ static int delete_from_lru_cache(struct page *p)
 	return -EIO;
 }
 
+static int truncate_error_page(struct page *p, unsigned long pfn,
+				struct address_space *mapping)
+{
+	int ret = MF_FAILED;
+
+	if (mapping->a_ops->error_remove_page) {
+		int err = mapping->a_ops->error_remove_page(mapping, p);
+
+		if (err != 0) {
+			pr_info("Memory failure: %#lx: Failed to punch page: %d\n",
+				pfn, err);
+		} else if (page_has_private(p) &&
+			   !try_to_release_page(p, GFP_NOIO)) {
+			pr_info("Memory failure: %#lx: failed to release buffers\n",
+				pfn);
+		} else {
+			ret = MF_RECOVERED;
+		}
+	} else {
+		/*
+		 * If the file system doesn't support it just invalidate
+		 * This fails on dirty or anything with private pages
+		 */
+		if (invalidate_inode_page(p))
+			ret = MF_RECOVERED;
+		else
+			pr_info("Memory failure: %#lx: Failed to invalidate\n",
+				pfn);
+	}
+
+	return ret;
+}
+
 /*
  * Error hit kernel page.
  * Do nothing, try to be lucky and not touch this instead. For a few cases we
@@ -579,8 +611,6 @@ static int me_unknown(struct page *p, unsigned long pfn)
  */
 static int me_pagecache_clean(struct page *p, unsigned long pfn)
 {
-	int err;
-	int ret = MF_FAILED;
 	struct address_space *mapping;
 
 	delete_from_lru_cache(p);
@@ -612,30 +642,7 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
 	 *
 	 * Open: to take i_mutex or not for this? Right now we don't.
 	 */
-	if (mapping->a_ops->error_remove_page) {
-		err = mapping->a_ops->error_remove_page(mapping, p);
-		if (err != 0) {
-			pr_info("Memory failure: %#lx: Failed to punch page: %d\n",
-				pfn, err);
-		} else if (page_has_private(p) &&
-				!try_to_release_page(p, GFP_NOIO)) {
-			pr_info("Memory failure: %#lx: failed to release buffers\n",
-				pfn);
-		} else {
-			ret = MF_RECOVERED;
-		}
-	} else {
-		/*
-		 * If the file system doesn't support it just invalidate
-		 * This fails on dirty or anything with private pages
-		 */
-		if (invalidate_inode_page(p))
-			ret = MF_RECOVERED;
-		else
-			pr_info("Memory failure: %#lx: Failed to invalidate\n",
-				pfn);
-	}
-	return ret;
+	return truncate_error_page(p, pfn, mapping);
 }
 
 /*
@@ -741,24 +748,29 @@ static int me_huge_page(struct page *p, unsigned long pfn)
 {
 	int res = 0;
 	struct page *hpage = compound_head(p);
+	struct address_space *mapping;
 
 	if (!PageHuge(hpage))
 		return MF_DELAYED;
 
-	/*
-	 * We can safely recover from error on free or reserved (i.e.
-	 * not in-use) hugepage by dequeuing it from freelist.
-	 * To check whether a hugepage is in-use or not, we can't use
-	 * page->lru because it can be used in other hugepage operations,
-	 * such as __unmap_hugepage_range() and gather_surplus_pages().
-	 * So instead we use page_mapping() and PageAnon().
-	 */
-	if (!(page_mapping(hpage) || PageAnon(hpage))) {
-		res = dequeue_hwpoisoned_huge_page(hpage);
-		if (!res)
-			return MF_RECOVERED;
+	mapping = page_mapping(hpage);
+	if (mapping) {
+		res = truncate_error_page(hpage, pfn, mapping);
+	} else {
+		unlock_page(hpage);
+		/*
+		 * migration entry prevents later access on error anonymous
+		 * hugepage, so we can free and dissolve it into buddy to
+		 * save healthy subpages.
+		 */
+		if (PageAnon(hpage))
+			put_page(hpage);
+		dissolve_free_huge_page(p);
+		res = MF_RECOVERED;
+		lock_page(hpage);
 	}
-	return MF_DELAYED;
+
+	return res;
 }
 
 /*
@@ -857,7 +869,7 @@ static int page_action(struct page_state *ps, struct page *p,
 	count = page_count(p) - 1;
 	if (ps->action == me_swapcache_dirty && result == MF_DELAYED)
 		count--;
-	if (count != 0) {
+	if (count > 0) {
 		pr_err("Memory failure: %#lx: %s still referenced by %d users\n",
 		       pfn, action_page_types[ps->type], count);
 		result = MF_FAILED;
@@ -1010,20 +1022,84 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
 	return unmap_success;
 }
 
-static void set_page_hwpoison_huge_page(struct page *hpage)
+static int identify_page_state(unsigned long pfn, struct page *p,
+				unsigned long page_flags)
 {
-	int i;
-	int nr_pages = 1 << compound_order(hpage);
-	for (i = 0; i < nr_pages; i++)
-		SetPageHWPoison(hpage + i);
+	struct page_state *ps;
+
+	/*
+	 * The first check uses the current page flags which may not have any
+	 * relevant information. The second check with the saved page flags is
+	 * carried out only if the first check can't determine the page status.
+	 */
+	for (ps = error_states;; ps++)
+		if ((p->flags & ps->mask) == ps->res)
+			break;
+
+	page_flags |= (p->flags & (1UL << PG_dirty));
+
+	if (!ps->mask)
+		for (ps = error_states;; ps++)
+			if ((page_flags & ps->mask) == ps->res)
+				break;
+	return page_action(ps, p, pfn);
 }
 
-static void clear_page_hwpoison_huge_page(struct page *hpage)
+static int memory_failure_hugetlb(unsigned long pfn, int trapno, int flags)
 {
-	int i;
-	int nr_pages = 1 << compound_order(hpage);
-	for (i = 0; i < nr_pages; i++)
-		ClearPageHWPoison(hpage + i);
+	struct page *p = pfn_to_page(pfn);
+	struct page *head = compound_head(p);
+	int res;
+	unsigned long page_flags;
+
+	if (TestSetPageHWPoison(head)) {
+		pr_err("Memory failure: %#lx: already hardware poisoned\n",
+		       pfn);
+		return 0;
+	}
+
+	num_poisoned_pages_inc();
+
+	if (!(flags & MF_COUNT_INCREASED) && !get_hwpoison_page(p)) {
+		/*
+		 * Check "filter hit" and "race with other subpage."
+		 */
+		lock_page(head);
+		if (PageHWPoison(head)) {
+			if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
+			    || (p != head && TestSetPageHWPoison(head))) {
+				num_poisoned_pages_dec();
+				unlock_page(head);
+				return 0;
+			}
+		}
+		unlock_page(head);
+		dissolve_free_huge_page(p);
+		action_result(pfn, MF_MSG_FREE_HUGE, MF_DELAYED);
+		return 0;
+	}
+
+	lock_page(head);
+	page_flags = head->flags;
+
+	if (!PageHWPoison(head)) {
+		pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
+		num_poisoned_pages_dec();
+		unlock_page(head);
+		put_hwpoison_page(head);
+		return 0;
+	}
+
+	if (!hwpoison_user_mappings(p, pfn, trapno, flags, &head)) {
+		action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
+		res = -EBUSY;
+		goto out;
+	}
+
+	res = identify_page_state(pfn, p, page_flags);
+out:
+	unlock_page(head);
+	return res;
 }
 
 /**
@@ -1046,12 +1122,10 @@ static void clear_page_hwpoison_huge_page(struct page *hpage)
  */
 int memory_failure(unsigned long pfn, int trapno, int flags)
 {
-	struct page_state *ps;
 	struct page *p;
 	struct page *hpage;
 	struct page *orig_head;
 	int res;
-	unsigned int nr_pages;
 	unsigned long page_flags;
 
 	if (!sysctl_memory_failure_recovery)
@@ -1064,34 +1138,22 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 	}
 
 	p = pfn_to_page(pfn);
-	orig_head = hpage = compound_head(p);
+	if (PageHuge(p))
+		return memory_failure_hugetlb(pfn, trapno, flags);
 	if (TestSetPageHWPoison(p)) {
 		pr_err("Memory failure: %#lx: already hardware poisoned\n",
 			pfn);
 		return 0;
 	}
 
-	/*
-	 * Currently errors on hugetlbfs pages are measured in hugepage units,
-	 * so nr_pages should be 1 << compound_order.  OTOH when errors are on
-	 * transparent hugepages, they are supposed to be split and error
-	 * measurement is done in normal page units.  So nr_pages should be one
-	 * in this case.
-	 */
-	if (PageHuge(p))
-		nr_pages = 1 << compound_order(hpage);
-	else /* normal page or thp */
-		nr_pages = 1;
-	num_poisoned_pages_add(nr_pages);
+	orig_head = hpage = compound_head(p);
+	num_poisoned_pages_inc();
 
 	/*
 	 * We need/can do nothing about count=0 pages.
 	 * 1) it's a free page, and therefore in safe hand:
 	 *    prep_new_page() will be the gate keeper.
-	 * 2) it's a free hugepage, which is also safe:
-	 *    an affected hugepage will be dequeued from hugepage freelist,
-	 *    so there's no concern about reusing it ever after.
-	 * 3) it's part of a non-compound high order page.
+	 * 2) it's part of a non-compound high order page.
 	 *    Implies some kernel user: cannot stop them from
 	 *    R/W the page; let's pray that the page has been
 	 *    used and will be freed some time later.
@@ -1102,32 +1164,13 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 		if (is_free_buddy_page(p)) {
 			action_result(pfn, MF_MSG_BUDDY, MF_DELAYED);
 			return 0;
-		} else if (PageHuge(hpage)) {
-			/*
-			 * Check "filter hit" and "race with other subpage."
-			 */
-			lock_page(hpage);
-			if (PageHWPoison(hpage)) {
-				if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
-				    || (p != hpage && TestSetPageHWPoison(hpage))) {
-					num_poisoned_pages_sub(nr_pages);
-					unlock_page(hpage);
-					return 0;
-				}
-			}
-			set_page_hwpoison_huge_page(hpage);
-			res = dequeue_hwpoisoned_huge_page(hpage);
-			action_result(pfn, MF_MSG_FREE_HUGE,
-				      res ? MF_IGNORED : MF_DELAYED);
-			unlock_page(hpage);
-			return res;
 		} else {
 			action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
 			return -EBUSY;
 		}
 	}
 
-	if (!PageHuge(p) && PageTransHuge(hpage)) {
+	if (PageTransHuge(hpage)) {
 		lock_page(p);
 		if (!PageAnon(p) || unlikely(split_huge_page(p))) {
 			unlock_page(p);
@@ -1138,7 +1181,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 				pr_err("Memory failure: %#lx: thp split failed\n",
 					pfn);
 			if (TestClearPageHWPoison(p))
-				num_poisoned_pages_sub(nr_pages);
+				num_poisoned_pages_dec();
 			put_hwpoison_page(p);
 			return -EBUSY;
 		}
@@ -1165,7 +1208,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 		return 0;
 	}
 
-	lock_page(hpage);
+	lock_page(p);
 
 	/*
 	 * The page could have changed compound pages during the locking.
@@ -1194,42 +1237,23 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 	 */
 	if (!PageHWPoison(p)) {
 		pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
-		num_poisoned_pages_sub(nr_pages);
-		unlock_page(hpage);
-		put_hwpoison_page(hpage);
+		num_poisoned_pages_dec();
+		unlock_page(p);
+		put_hwpoison_page(p);
 		return 0;
 	}
 	if (hwpoison_filter(p)) {
 		if (TestClearPageHWPoison(p))
-			num_poisoned_pages_sub(nr_pages);
-		unlock_page(hpage);
-		put_hwpoison_page(hpage);
+			num_poisoned_pages_dec();
+		unlock_page(p);
+		put_hwpoison_page(p);
 		return 0;
 	}
 
-	if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p))
+	if (!PageTransTail(p) && !PageLRU(p))
 		goto identify_page_state;
 
 	/*
-	 * For error on the tail page, we should set PG_hwpoison
-	 * on the head page to show that the hugepage is hwpoisoned
-	 */
-	if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
-		action_result(pfn, MF_MSG_POISONED_HUGE, MF_IGNORED);
-		unlock_page(hpage);
-		put_hwpoison_page(hpage);
-		return 0;
-	}
-	/*
-	 * Set PG_hwpoison on all pages in an error hugepage,
-	 * because containment is done in hugepage unit for now.
-	 * Since we have done TestSetPageHWPoison() for the head page with
-	 * page lock held, we can safely set PG_hwpoison bits on tail pages.
-	 */
-	if (PageHuge(p))
-		set_page_hwpoison_huge_page(hpage);
-
-	/*
 	 * It's very difficult to mess with pages currently under IO
 	 * and in many cases impossible, so we just avoid it here.
 	 */
@@ -1258,25 +1282,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 	}
 
 identify_page_state:
-	res = -EBUSY;
-	/*
-	 * The first check uses the current page flags which may not have any
-	 * relevant information. The second check with the saved page flagss is
-	 * carried out only if the first check can't determine the page status.
-	 */
-	for (ps = error_states;; ps++)
-		if ((p->flags & ps->mask) == ps->res)
-			break;
-
-	page_flags |= (p->flags & (1UL << PG_dirty));
-
-	if (!ps->mask)
-		for (ps = error_states;; ps++)
-			if ((page_flags & ps->mask) == ps->res)
-				break;
-	res = page_action(ps, p, pfn);
+	res = identify_page_state(pfn, p, page_flags);
 out:
-	unlock_page(hpage);
+	unlock_page(p);
 	return res;
 }
 EXPORT_SYMBOL_GPL(memory_failure);
@@ -1398,7 +1406,6 @@ int unpoison_memory(unsigned long pfn)
 	struct page *page;
 	struct page *p;
 	int freeit = 0;
-	unsigned int nr_pages;
 	static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
 					DEFAULT_RATELIMIT_BURST);
 
@@ -1443,20 +1450,7 @@ int unpoison_memory(unsigned long pfn)
 		return 0;
 	}
 
-	nr_pages = 1 << compound_order(page);
-
 	if (!get_hwpoison_page(p)) {
-		/*
-		 * Since HWPoisoned hugepage should have non-zero refcount,
-		 * race between memory failure and unpoison seems to happen.
-		 * In such case unpoison fails and memory failure runs
-		 * to the end.
-		 */
-		if (PageHuge(page)) {
-			unpoison_pr_info("Unpoison: Memory failure is now running on free hugepage %#lx\n",
-					 pfn, &unpoison_rs);
-			return 0;
-		}
 		if (TestClearPageHWPoison(p))
 			num_poisoned_pages_dec();
 		unpoison_pr_info("Unpoison: Software-unpoisoned free page %#lx\n",
@@ -1474,10 +1468,8 @@ int unpoison_memory(unsigned long pfn)
 	if (TestClearPageHWPoison(page)) {
 		unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
 				 pfn, &unpoison_rs);
-		num_poisoned_pages_sub(nr_pages);
+		num_poisoned_pages_dec();
 		freeit = 1;
-		if (PageHuge(page))
-			clear_page_hwpoison_huge_page(page);
 	}
 	unlock_page(page);
 
@@ -1492,16 +1484,8 @@ EXPORT_SYMBOL(unpoison_memory);
 static struct page *new_page(struct page *p, unsigned long private, int **x)
 {
 	int nid = page_to_nid(p);
-	if (PageHuge(p)) {
-		struct hstate *hstate = page_hstate(compound_head(p));
-
-		if (hstate_is_gigantic(hstate))
-			return alloc_huge_page_node(hstate, NUMA_NO_NODE);
 
-		return alloc_huge_page_node(hstate, nid);
-	} else {
-		return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0);
-	}
+	return new_page_nodemask(p, nid, &node_states[N_MEMORY]);
 }
 
 /*
@@ -1608,15 +1592,8 @@ static int soft_offline_huge_page(struct page *page, int flags)
 		if (ret > 0)
 			ret = -EIO;
 	} else {
-		/* overcommit hugetlb page will be freed to buddy */
-		if (PageHuge(page)) {
-			set_page_hwpoison_huge_page(hpage);
-			dequeue_hwpoisoned_huge_page(hpage);
-			num_poisoned_pages_add(1 << compound_order(hpage));
-		} else {
-			SetPageHWPoison(page);
-			num_poisoned_pages_inc();
-		}
+		if (PageHuge(page))
+			dissolve_free_huge_page(page);
 	}
 	return ret;
 }
@@ -1732,15 +1709,12 @@ static int soft_offline_in_use_page(struct page *page, int flags)
 
 static void soft_offline_free_page(struct page *page)
 {
-	if (PageHuge(page)) {
-		struct page *hpage = compound_head(page);
+	struct page *head = compound_head(page);
 
-		set_page_hwpoison_huge_page(hpage);
-		if (!dequeue_hwpoisoned_huge_page(hpage))
-			num_poisoned_pages_add(1 << compound_order(hpage));
-	} else {
-		if (!TestSetPageHWPoison(page))
-			num_poisoned_pages_inc();
+	if (!TestSetPageHWPoison(head)) {
+		num_poisoned_pages_inc();
+		if (PageHuge(head))
+			dissolve_free_huge_page(page);
 	}
 }