Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Merge 'net' bug fixes into 'net-next' as we have patches
that will build on top of them.

This merge commit includes a change from Emil Goode
(emilgoode@gmail.com) that fixes a warning that would
have been introduced by this merge.  Specifically it
fixes the pingv6_ops method ipv6_chk_addr() to add a
"const" to the "struct net_device *dev" argument and
likewise update the dummy_ipv6_chk_addr() declaration.

Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 100 insertions, 81 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 03a89a2..362c329 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2325,7 +2325,12 @@ static void collapse_huge_page(struct mm_struct *mm,
 		pte_unmap(pte);
 		spin_lock(&mm->page_table_lock);
 		BUG_ON(!pmd_none(*pmd));
-		set_pmd_at(mm, address, pmd, _pmd);
+		/*
+		 * We can only use set_pmd_at when establishing
+		 * hugepmds and never for establishing regular pmds that
+		 * points to regular pagetables. Use pmd_populate for that
+		 */
+		pmd_populate(mm, pmd, pmd_pgtable(_pmd));
 		spin_unlock(&mm->page_table_lock);
 		anon_vma_unlock_write(vma->anon_vma);
 		goto out;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index cb1c9de..010d6c1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4108,8 +4108,6 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
 	if (mem_cgroup_disabled())
 		return NULL;
 
-	VM_BUG_ON(PageSwapCache(page));
-
 	if (PageTransHuge(page)) {
 		nr_pages <<= compound_order(page);
 		VM_BUG_ON(!PageTransHuge(page));
@@ -4205,6 +4203,18 @@ void mem_cgroup_uncharge_page(struct page *page)
 	if (page_mapped(page))
 		return;
 	VM_BUG_ON(page->mapping && !PageAnon(page));
+	/*
+	 * If the page is in swap cache, uncharge should be deferred
+	 * to the swap path, which also properly accounts swap usage
+	 * and handles memcg lifetime.
+	 *
+	 * Note that this check is not stable and reclaim may add the
+	 * page to swap cache at any time after this.  However, if the
+	 * page is not in swap cache by the time page->mapcount hits
+	 * 0, there won't be any page table references to the swap
+	 * slot, and reclaim will free it and not actually write the
+	 * page to disk.
+	 */
 	if (PageSwapCache(page))
 		return;
 	__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a221fac..1ad92b4 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -720,9 +720,12 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
 	start = phys_start_pfn << PAGE_SHIFT;
 	size = nr_pages * PAGE_SIZE;
 	ret = release_mem_region_adjustable(&iomem_resource, start, size);
-	if (ret)
-		pr_warn("Unable to release resource <%016llx-%016llx> (%d)\n",
-				start, start + size - 1, ret);
+	if (ret) {
+		resource_size_t endres = start + size - 1;
+
+		pr_warn("Unable to release resource <%pa-%pa> (%d)\n",
+				&start, &endres, ret);
+	}
 
 	sections_to_remove = nr_pages / PAGES_PER_SECTION;
 	for (i = 0; i < sections_to_remove; i++) {
diff --git a/mm/migrate.c b/mm/migrate.c
index 27ed225..b1f5750 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -165,7 +165,7 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
 		pte = arch_make_huge_pte(pte, vma, new, 0);
 	}
 #endif
-	flush_cache_page(vma, addr, pte_pfn(pte));
+	flush_dcache_page(new);
 	set_pte_at(mm, addr, ptep, pte);
 
 	if (PageHuge(new)) {
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index be04122..6725ff1 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -40,48 +40,44 @@ void __mmu_notifier_release(struct mm_struct *mm)
 	int id;
 
 	/*
-	 * srcu_read_lock() here will block synchronize_srcu() in
-	 * mmu_notifier_unregister() until all registered
-	 * ->release() callouts this function makes have
-	 * returned.
+	 * SRCU here will block mmu_notifier_unregister until
+	 * ->release returns.
 	 */
 	id = srcu_read_lock(&srcu);
+	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist)
+		/*
+		 * If ->release runs before mmu_notifier_unregister it must be
+		 * handled, as it's the only way for the driver to flush all
+		 * existing sptes and stop the driver from establishing any more
+		 * sptes before all the pages in the mm are freed.
+		 */
+		if (mn->ops->release)
+			mn->ops->release(mn, mm);
+	srcu_read_unlock(&srcu, id);
+
 	spin_lock(&mm->mmu_notifier_mm->lock);
 	while (unlikely(!hlist_empty(&mm->mmu_notifier_mm->list))) {
 		mn = hlist_entry(mm->mmu_notifier_mm->list.first,
 				 struct mmu_notifier,
 				 hlist);
-
 		/*
-		 * Unlink.  This will prevent mmu_notifier_unregister()
-		 * from also making the ->release() callout.
+		 * We arrived before mmu_notifier_unregister so
+		 * mmu_notifier_unregister will do nothing other than to wait
+		 * for ->release to finish and for mmu_notifier_unregister to
+		 * return.
 		 */
 		hlist_del_init_rcu(&mn->hlist);
-		spin_unlock(&mm->mmu_notifier_mm->lock);
-
-		/*
-		 * Clear sptes. (see 'release' description in mmu_notifier.h)
-		 */
-		if (mn->ops->release)
-			mn->ops->release(mn, mm);
-
-		spin_lock(&mm->mmu_notifier_mm->lock);
 	}
 	spin_unlock(&mm->mmu_notifier_mm->lock);
 
 	/*
-	 * All callouts to ->release() which we have done are complete.
-	 * Allow synchronize_srcu() in mmu_notifier_unregister() to complete
-	 */
-	srcu_read_unlock(&srcu, id);
-
-	/*
-	 * mmu_notifier_unregister() may have unlinked a notifier and may
-	 * still be calling out to it.	Additionally, other notifiers
-	 * may have been active via vmtruncate() et. al. Block here
-	 * to ensure that all notifier callouts for this mm have been
-	 * completed and the sptes are really cleaned up before returning
-	 * to exit_mmap().
+	 * synchronize_srcu here prevents mmu_notifier_release from returning to
+	 * exit_mmap (which would proceed with freeing all pages in the mm)
+	 * until the ->release method returns, if it was invoked by
+	 * mmu_notifier_unregister.
+	 *
+	 * The mmu_notifier_mm can't go away from under us because one mm_count
+	 * is held by exit_mmap.
 	 */
 	synchronize_srcu(&srcu);
 }
@@ -292,31 +288,34 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
 {
 	BUG_ON(atomic_read(&mm->mm_count) <= 0);
 
-	spin_lock(&mm->mmu_notifier_mm->lock);
 	if (!hlist_unhashed(&mn->hlist)) {
+		/*
+		 * SRCU here will force exit_mmap to wait for ->release to
+		 * finish before freeing the pages.
+		 */
 		int id;
 
+		id = srcu_read_lock(&srcu);
 		/*
-		 * Ensure we synchronize up with __mmu_notifier_release().
+		 * exit_mmap will block in mmu_notifier_release to guarantee
+		 * that ->release is called before freeing the pages.
 		 */
-		id = srcu_read_lock(&srcu);
-
-		hlist_del_rcu(&mn->hlist);
-		spin_unlock(&mm->mmu_notifier_mm->lock);
-
 		if (mn->ops->release)
 			mn->ops->release(mn, mm);
+		srcu_read_unlock(&srcu, id);
 
+		spin_lock(&mm->mmu_notifier_mm->lock);
 		/*
-		 * Allow __mmu_notifier_release() to complete.
+		 * Can not use list_del_rcu() since __mmu_notifier_release
+		 * can delete it before we hold the lock.
 		 */
-		srcu_read_unlock(&srcu, id);
-	} else
+		hlist_del_init_rcu(&mn->hlist);
 		spin_unlock(&mm->mmu_notifier_mm->lock);
+	}
 
 	/*
-	 * Wait for any running method to finish, including ->release() if it
-	 * was run by __mmu_notifier_release() instead of us.
+	 * Wait for any running method to finish, of course including
+	 * ->release if it was run by mmu_notifier_relase instead of us.
 	 */
 	synchronize_srcu(&srcu);
 
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 35aa294..5da2cbc 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -127,28 +127,7 @@ static int walk_hugetlb_range(struct vm_area_struct *vma,
 	return 0;
 }
 
-static struct vm_area_struct* hugetlb_vma(unsigned long addr, struct mm_walk *walk)
-{
-	struct vm_area_struct *vma;
-
-	/* We don't need vma lookup at all. */
-	if (!walk->hugetlb_entry)
-		return NULL;
-
-	VM_BUG_ON(!rwsem_is_locked(&walk->mm->mmap_sem));
-	vma = find_vma(walk->mm, addr);
-	if (vma && vma->vm_start <= addr && is_vm_hugetlb_page(vma))
-		return vma;
-
-	return NULL;
-}
-
 #else /* CONFIG_HUGETLB_PAGE */
-static struct vm_area_struct* hugetlb_vma(unsigned long addr, struct mm_walk *walk)
-{
-	return NULL;
-}
-
 static int walk_hugetlb_range(struct vm_area_struct *vma,
 			      unsigned long addr, unsigned long end,
 			      struct mm_walk *walk)
@@ -198,30 +177,53 @@ int walk_page_range(unsigned long addr, unsigned long end,
 	if (!walk->mm)
 		return -EINVAL;
 
+	VM_BUG_ON(!rwsem_is_locked(&walk->mm->mmap_sem));
+
 	pgd = pgd_offset(walk->mm, addr);
 	do {
-		struct vm_area_struct *vma;
+		struct vm_area_struct *vma = NULL;
 
 		next = pgd_addr_end(addr, end);
 
 		/*
-		 * handle hugetlb vma individually because pagetable walk for
-		 * the hugetlb page is dependent on the architecture and
-		 * we can't handled it in the same manner as non-huge pages.
+		 * This function was not intended to be vma based.
+		 * But there are vma special cases to be handled:
+		 * - hugetlb vma's
+		 * - VM_PFNMAP vma's
 		 */
-		vma = hugetlb_vma(addr, walk);
+		vma = find_vma(walk->mm, addr);
 		if (vma) {
-			if (vma->vm_end < next)
+			/*
+			 * There are no page structures backing a VM_PFNMAP
+			 * range, so do not allow split_huge_page_pmd().
+			 */
+			if ((vma->vm_start <= addr) &&
+			    (vma->vm_flags & VM_PFNMAP)) {
 				next = vma->vm_end;
+				pgd = pgd_offset(walk->mm, next);
+				continue;
+			}
 			/*
-			 * Hugepage is very tightly coupled with vma, so
-			 * walk through hugetlb entries within a given vma.
+			 * Handle hugetlb vma individually because pagetable
+			 * walk for the hugetlb page is dependent on the
+			 * architecture and we can't handled it in the same
+			 * manner as non-huge pages.
 			 */
-			err = walk_hugetlb_range(vma, addr, next, walk);
-			if (err)
-				break;
-			pgd = pgd_offset(walk->mm, next);
-			continue;
+			if (walk->hugetlb_entry && (vma->vm_start <= addr) &&
+			    is_vm_hugetlb_page(vma)) {
+				if (vma->vm_end < next)
+					next = vma->vm_end;
+				/*
+				 * Hugepage is very tightly coupled with vma,
+				 * so walk through hugetlb entries within a
+				 * given vma.
+				 */
+				err = walk_hugetlb_range(vma, addr, next, walk);
+				if (err)
+					break;
+				pgd = pgd_offset(walk->mm, next);
+				continue;
+			}
 		}
 
 		if (pgd_none_or_clear_bad(pgd)) {