nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 84 insertions, 28 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 8d01243d956..2624edcfb42 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -553,7 +553,7 @@ void putback_lru_page(struct page *page)
 redo:
 	ClearPageUnevictable(page);
 
-	if (page_evictable(page, NULL)) {
+	if (page_evictable(page)) {
 		/*
 		 * For evictable pages, we can use the cache.
 		 * In event of a race, worst case is we end up with an
@@ -587,7 +587,7 @@ redo:
 	 * page is on unevictable list, it never be freed. To avoid that,
 	 * check after we added it to the list, again.
 	 */
-	if (lru == LRU_UNEVICTABLE && page_evictable(page, NULL)) {
+	if (lru == LRU_UNEVICTABLE && page_evictable(page)) {
 		if (!isolate_lru_page(page)) {
 			put_page(page);
 			goto redo;
@@ -674,8 +674,10 @@ static enum page_references page_check_references(struct page *page,
 static unsigned long shrink_page_list(struct list_head *page_list,
 				      struct zone *zone,
 				      struct scan_control *sc,
+				      enum ttu_flags ttu_flags,
 				      unsigned long *ret_nr_dirty,
-				      unsigned long *ret_nr_writeback)
+				      unsigned long *ret_nr_writeback,
+				      bool force_reclaim)
 {
 	LIST_HEAD(ret_pages);
 	LIST_HEAD(free_pages);
@@ -689,10 +691,10 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 
 	mem_cgroup_uncharge_start();
 	while (!list_empty(page_list)) {
-		enum page_references references;
 		struct address_space *mapping;
 		struct page *page;
 		int may_enter_fs;
+		enum page_references references = PAGEREF_RECLAIM_CLEAN;
 
 		cond_resched();
 
@@ -707,7 +709,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 
 		sc->nr_scanned++;
 
-		if (unlikely(!page_evictable(page, NULL)))
+		if (unlikely(!page_evictable(page)))
 			goto cull_mlocked;
 
 		if (!sc->may_unmap && page_mapped(page))
@@ -758,7 +760,9 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			wait_on_page_writeback(page);
 		}
 
-		references = page_check_references(page, sc);
+		if (!force_reclaim)
+			references = page_check_references(page, sc);
+
 		switch (references) {
 		case PAGEREF_ACTIVATE:
 			goto activate_locked;
@@ -788,7 +792,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 		 * processes. Try to unmap it here.
 		 */
 		if (page_mapped(page) && mapping) {
-			switch (try_to_unmap(page, TTU_UNMAP)) {
+			switch (try_to_unmap(page, ttu_flags)) {
 			case SWAP_FAIL:
 				goto activate_locked;
 			case SWAP_AGAIN:
@@ -960,6 +964,33 @@ keep:
 	return nr_reclaimed;
 }
 
+unsigned long reclaim_clean_pages_from_list(struct zone *zone,
+					    struct list_head *page_list)
+{
+	struct scan_control sc = {
+		.gfp_mask = GFP_KERNEL,
+		.priority = DEF_PRIORITY,
+		.may_unmap = 1,
+	};
+	unsigned long ret, dummy1, dummy2;
+	struct page *page, *next;
+	LIST_HEAD(clean_pages);
+
+	list_for_each_entry_safe(page, next, page_list, lru) {
+		if (page_is_file_cache(page) && !PageDirty(page)) {
+			ClearPageActive(page);
+			list_move(&page->lru, &clean_pages);
+		}
+	}
+
+	ret = shrink_page_list(&clean_pages, zone, &sc,
+				TTU_UNMAP|TTU_IGNORE_ACCESS,
+				&dummy1, &dummy2, true);
+	list_splice(&clean_pages, page_list);
+	__mod_zone_page_state(zone, NR_ISOLATED_FILE, -ret);
+	return ret;
+}
+
 /*
  * Attempt to remove the specified page from its LRU.  Only take this page
  * if it is of the appropriate PageActive status.  Pages which are being
@@ -978,8 +1009,8 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode)
 	if (!PageLRU(page))
 		return ret;
 
-	/* Do not give back unevictable pages for compaction */
-	if (PageUnevictable(page))
+	/* Compaction should not handle unevictable pages but CMA can do so */
+	if (PageUnevictable(page) && !(mode & ISOLATE_UNEVICTABLE))
 		return ret;
 
 	ret = -EBUSY;
@@ -1186,7 +1217,7 @@ putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list)
 
 		VM_BUG_ON(PageLRU(page));
 		list_del(&page->lru);
-		if (unlikely(!page_evictable(page, NULL))) {
+		if (unlikely(!page_evictable(page))) {
 			spin_unlock_irq(&zone->lru_lock);
 			putback_lru_page(page);
 			spin_lock_irq(&zone->lru_lock);
@@ -1278,8 +1309,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
 	if (nr_taken == 0)
 		return 0;
 
-	nr_reclaimed = shrink_page_list(&page_list, zone, sc,
-						&nr_dirty, &nr_writeback);
+	nr_reclaimed = shrink_page_list(&page_list, zone, sc, TTU_UNMAP,
+					&nr_dirty, &nr_writeback, false);
 
 	spin_lock_irq(&zone->lru_lock);
 
@@ -1439,7 +1470,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
 		page = lru_to_page(&l_hold);
 		list_del(&page->lru);
 
-		if (unlikely(!page_evictable(page, NULL))) {
+		if (unlikely(!page_evictable(page))) {
 			putback_lru_page(page);
 			continue;
 		}
@@ -1729,6 +1760,28 @@ static bool in_reclaim_compaction(struct scan_control *sc)
 	return false;
 }
 
+#ifdef CONFIG_COMPACTION
+/*
+ * If compaction is deferred for sc->order then scale the number of pages
+ * reclaimed based on the number of consecutive allocation failures
+ */
+static unsigned long scale_for_compaction(unsigned long pages_for_compaction,
+			struct lruvec *lruvec, struct scan_control *sc)
+{
+	struct zone *zone = lruvec_zone(lruvec);
+
+	if (zone->compact_order_failed <= sc->order)
+		pages_for_compaction <<= zone->compact_defer_shift;
+	return pages_for_compaction;
+}
+#else
+static unsigned long scale_for_compaction(unsigned long pages_for_compaction,
+			struct lruvec *lruvec, struct scan_control *sc)
+{
+	return pages_for_compaction;
+}
+#endif
+
 /*
  * Reclaim/compaction is used for high-order allocation requests. It reclaims
  * order-0 pages before compacting the zone. should_continue_reclaim() returns
@@ -1776,6 +1829,9 @@ static inline bool should_continue_reclaim(struct lruvec *lruvec,
 	 * inactive lists are large enough, continue reclaiming
 	 */
 	pages_for_compaction = (2UL << sc->order);
+
+	pages_for_compaction = scale_for_compaction(pages_for_compaction,
+						    lruvec, sc);
 	inactive_lru_pages = get_lru_size(lruvec, LRU_INACTIVE_FILE);
 	if (nr_swap_pages > 0)
 		inactive_lru_pages += get_lru_size(lruvec, LRU_INACTIVE_ANON);
@@ -2839,6 +2895,14 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order, int classzone_idx)
 		 */
 		set_pgdat_percpu_threshold(pgdat, calculate_normal_threshold);
 
+		/*
+		 * Compaction records what page blocks it recently failed to
+		 * isolate pages from and skips them in the future scanning.
+		 * When kswapd is going to sleep, it is reasonable to assume
+		 * that pages and compaction may succeed so reset the cache.
+		 */
+		reset_isolation_suitable(pgdat);
+
 		if (!kthread_should_stop())
 			schedule();
 
@@ -3101,8 +3165,9 @@ int kswapd_run(int nid)
 	if (IS_ERR(pgdat->kswapd)) {
 		/* failure at boot is fatal */
 		BUG_ON(system_state == SYSTEM_BOOTING);
-		printk("Failed to start kswapd on node %d\n",nid);
-		ret = -1;
+		pgdat->kswapd = NULL;
+		pr_err("Failed to start kswapd on node %d\n", nid);
+		ret = PTR_ERR(pgdat->kswapd);
 	}
 	return ret;
 }
@@ -3349,27 +3414,18 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 /*
  * page_evictable - test whether a page is evictable
  * @page: the page to test
- * @vma: the VMA in which the page is or will be mapped, may be NULL
  *
  * Test whether page is evictable--i.e., should be placed on active/inactive
- * lists vs unevictable list.  The vma argument is !NULL when called from the
- * fault path to determine how to instantate a new page.
+ * lists vs unevictable list.
  *
  * Reasons page might not be evictable:
  * (1) page's mapping marked unevictable
  * (2) page is part of an mlocked VMA
  *
  */
-int page_evictable(struct page *page, struct vm_area_struct *vma)
+int page_evictable(struct page *page)
 {
-
-	if (mapping_unevictable(page_mapping(page)))
-		return 0;
-
-	if (PageMlocked(page) || (vma && mlocked_vma_newpage(vma, page)))
-		return 0;
-
-	return 1;
+	return !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
 }
 
 #ifdef CONFIG_SHMEM
@@ -3407,7 +3463,7 @@ void check_move_unevictable_pages(struct page **pages, int nr_pages)
 		if (!PageLRU(page) || !PageUnevictable(page))
 			continue;
 
-		if (page_evictable(page, NULL)) {
+		if (page_evictable(page)) {
 			enum lru_list lru = page_lru_base_type(page);
 
 			VM_BUG_ON(PageActive(page));