Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "24 patches, based on 4a09d388f2ab382f217a764e6a152b3f614246f6.

  Subsystems affected by this patch series: mm (thp, vmalloc, hugetlb,
  memory-failure, and pagealloc), nilfs2, kthread, MAINTAINERS, and
  mailmap"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (24 commits)
  mailmap: add Marek's other e-mail address and identity without diacritics
  MAINTAINERS: fix Marek's identity again
  mm/page_alloc: do bulk array bounds check after checking populated elements
  mm/page_alloc: __alloc_pages_bulk(): do bounds check before accessing array
  mm/hwpoison: do not lock page again when me_huge_page() successfully recovers
  mm,hwpoison: return -EHWPOISON to denote that the page has already been poisoned
  mm/memory-failure: use a mutex to avoid memory_failure() races
  mm, futex: fix shared futex pgoff on shmem huge page
  kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync()
  kthread_worker: split code for canceling the delayed work timer
  mm/vmalloc: unbreak kasan vmalloc support
  KVM: s390: prepare for hugepage vmalloc
  mm/vmalloc: add vmalloc_no_huge
  nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
  mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk()
  mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes
  mm: page_vma_mapped_walk(): get vma_address_end() earlier
  mm: page_vma_mapped_walk(): use goto instead of while (1)
  mm: page_vma_mapped_walk(): add a level of indentation
  mm: page_vma_mapped_walk(): crossing page table boundary
  ...

1 files changed, 55 insertions, 28 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 0143d32bc666..6f5f78885ab4 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -658,6 +658,7 @@ static int truncate_error_page(struct page *p, unsigned long pfn,
  */
 static int me_kernel(struct page *p, unsigned long pfn)
 {
+	unlock_page(p);
 	return MF_IGNORED;
 }
 
@@ -667,6 +668,7 @@ static int me_kernel(struct page *p, unsigned long pfn)
 static int me_unknown(struct page *p, unsigned long pfn)
 {
 	pr_err("Memory failure: %#lx: Unknown page state\n", pfn);
+	unlock_page(p);
 	return MF_FAILED;
 }
 
@@ -675,6 +677,7 @@ static int me_unknown(struct page *p, unsigned long pfn)
  */
 static int me_pagecache_clean(struct page *p, unsigned long pfn)
 {
+	int ret;
 	struct address_space *mapping;
 
 	delete_from_lru_cache(p);
@@ -683,8 +686,10 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
 	 * For anonymous pages we're done the only reference left
 	 * should be the one m_f() holds.
 	 */
-	if (PageAnon(p))
-		return MF_RECOVERED;
+	if (PageAnon(p)) {
+		ret = MF_RECOVERED;
+		goto out;
+	}
 
 	/*
 	 * Now truncate the page in the page cache. This is really
@@ -698,7 +703,8 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
 		/*
 		 * Page has been teared down in the meanwhile
 		 */
-		return MF_FAILED;
+		ret = MF_FAILED;
+		goto out;
 	}
 
 	/*
@@ -706,7 +712,10 @@ 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.
 	 */
-	return truncate_error_page(p, pfn, mapping);
+	ret = truncate_error_page(p, pfn, mapping);
+out:
+	unlock_page(p);
+	return ret;
 }
 
 /*
@@ -782,24 +791,26 @@ static int me_pagecache_dirty(struct page *p, unsigned long pfn)
  */
 static int me_swapcache_dirty(struct page *p, unsigned long pfn)
 {
+	int ret;
+
 	ClearPageDirty(p);
 	/* Trigger EIO in shmem: */
 	ClearPageUptodate(p);
 
-	if (!delete_from_lru_cache(p))
-		return MF_DELAYED;
-	else
-		return MF_FAILED;
+	ret = delete_from_lru_cache(p) ? MF_FAILED : MF_DELAYED;
+	unlock_page(p);
+	return ret;
 }
 
 static int me_swapcache_clean(struct page *p, unsigned long pfn)
 {
+	int ret;
+
 	delete_from_swap_cache(p);
 
-	if (!delete_from_lru_cache(p))
-		return MF_RECOVERED;
-	else
-		return MF_FAILED;
+	ret = delete_from_lru_cache(p) ? MF_FAILED : MF_RECOVERED;
+	unlock_page(p);
+	return ret;
 }
 
 /*
@@ -820,6 +831,7 @@ static int me_huge_page(struct page *p, unsigned long pfn)
 	mapping = page_mapping(hpage);
 	if (mapping) {
 		res = truncate_error_page(hpage, pfn, mapping);
+		unlock_page(hpage);
 	} else {
 		res = MF_FAILED;
 		unlock_page(hpage);
@@ -834,7 +846,6 @@ static int me_huge_page(struct page *p, unsigned long pfn)
 			page_ref_inc(p);
 			res = MF_RECOVERED;
 		}
-		lock_page(hpage);
 	}
 
 	return res;
@@ -866,6 +877,8 @@ static struct page_state {
 	unsigned long mask;
 	unsigned long res;
 	enum mf_action_page_type type;
+
+	/* Callback ->action() has to unlock the relevant page inside it. */
 	int (*action)(struct page *p, unsigned long pfn);
 } error_states[] = {
 	{ reserved,	reserved,	MF_MSG_KERNEL,	me_kernel },
@@ -929,6 +942,7 @@ static int page_action(struct page_state *ps, struct page *p,
 	int result;
 	int count;
 
+	/* page p should be unlocked after returning from ps->action().  */
 	result = ps->action(p, pfn);
 
 	count = page_count(p) - 1;
@@ -1253,7 +1267,7 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags)
 	if (TestSetPageHWPoison(head)) {
 		pr_err("Memory failure: %#lx: already hardware poisoned\n",
 		       pfn);
-		return 0;
+		return -EHWPOISON;
 	}
 
 	num_poisoned_pages_inc();
@@ -1313,7 +1327,7 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags)
 		goto out;
 	}
 
-	res = identify_page_state(pfn, p, page_flags);
+	return identify_page_state(pfn, p, page_flags);
 out:
 	unlock_page(head);
 	return res;
@@ -1429,9 +1443,10 @@ int memory_failure(unsigned long pfn, int flags)
 	struct page *hpage;
 	struct page *orig_head;
 	struct dev_pagemap *pgmap;
-	int res;
+	int res = 0;
 	unsigned long page_flags;
 	bool retry = true;
+	static DEFINE_MUTEX(mf_mutex);
 
 	if (!sysctl_memory_failure_recovery)
 		panic("Memory failure on page %lx", pfn);
@@ -1449,13 +1464,19 @@ int memory_failure(unsigned long pfn, int flags)
 		return -ENXIO;
 	}
 
+	mutex_lock(&mf_mutex);
+
 try_again:
-	if (PageHuge(p))
-		return memory_failure_hugetlb(pfn, flags);
+	if (PageHuge(p)) {
+		res = memory_failure_hugetlb(pfn, flags);
+		goto unlock_mutex;
+	}
+
 	if (TestSetPageHWPoison(p)) {
 		pr_err("Memory failure: %#lx: already hardware poisoned\n",
 			pfn);
-		return 0;
+		res = -EHWPOISON;
+		goto unlock_mutex;
 	}
 
 	orig_head = hpage = compound_head(p);
@@ -1488,17 +1509,19 @@ try_again:
 				res = MF_FAILED;
 			}
 			action_result(pfn, MF_MSG_BUDDY, res);
-			return res == MF_RECOVERED ? 0 : -EBUSY;
+			res = res == MF_RECOVERED ? 0 : -EBUSY;
 		} else {
 			action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
-			return -EBUSY;
+			res = -EBUSY;
 		}
+		goto unlock_mutex;
 	}
 
 	if (PageTransHuge(hpage)) {
 		if (try_to_split_thp_page(p, "Memory Failure") < 0) {
 			action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
-			return -EBUSY;
+			res = -EBUSY;
+			goto unlock_mutex;
 		}
 		VM_BUG_ON_PAGE(!page_count(p), p);
 	}
@@ -1522,7 +1545,7 @@ try_again:
 	if (PageCompound(p) && compound_head(p) != orig_head) {
 		action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
 		res = -EBUSY;
-		goto out;
+		goto unlock_page;
 	}
 
 	/*
@@ -1542,14 +1565,14 @@ try_again:
 		num_poisoned_pages_dec();
 		unlock_page(p);
 		put_page(p);
-		return 0;
+		goto unlock_mutex;
 	}
 	if (hwpoison_filter(p)) {
 		if (TestClearPageHWPoison(p))
 			num_poisoned_pages_dec();
 		unlock_page(p);
 		put_page(p);
-		return 0;
+		goto unlock_mutex;
 	}
 
 	/*
@@ -1573,7 +1596,7 @@ try_again:
 	if (!hwpoison_user_mappings(p, pfn, flags, &p)) {
 		action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
 		res = -EBUSY;
-		goto out;
+		goto unlock_page;
 	}
 
 	/*
@@ -1582,13 +1605,17 @@ try_again:
 	if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
 		action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
 		res = -EBUSY;
-		goto out;
+		goto unlock_page;
 	}
 
 identify_page_state:
 	res = identify_page_state(pfn, p, page_flags);
-out:
+	mutex_unlock(&mf_mutex);
+	return res;
+unlock_page:
 	unlock_page(p);
+unlock_mutex:
+	mutex_unlock(&mf_mutex);
 	return res;
 }
 EXPORT_SYMBOL_GPL(memory_failure);