Merge tag 'mvebu-defconfig-4.6-1' of git://git.infradead.org/linux-mvebu into next...

[deliverable/linux.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bd620b65db52680fc8a6e221fe90189c22dca2f1..71b1c29948dba30aab0a894ddc7c84eb62acde2b 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -46,6 +46,7 @@
 #include <linux/oom.h>
 #include <linux/prefetch.h>
 #include <linux/printk.h>
+#include <linux/dax.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -671,9 +672,15 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
                 * inode reclaim needs to empty out the radix tree or
                 * the nodes are lost.  Don't plant shadows behind its
                 * back.
+                *
+                * We also don't store shadows for DAX mappings because the
+                * only page cache pages found in these are zero pages
+                * covering holes, and because we don't want to mix DAX
+                * exceptional entries and shadow exceptional entries in the
+                * same page_tree.
                 */
                if (reclaimed && page_is_file_cache(page) &&
-                   !mapping_exiting(mapping))
+                   !mapping_exiting(mapping) && !dax_mapping(mapping))
                        shadow = workingset_eviction(mapping, page);
                __delete_from_page_cache(page, shadow, memcg);
                spin_unlock_irqrestore(&mapping->tree_lock, flags);
@@ -1436,7 +1443,7 @@ int isolate_lru_page(struct page *page)
        int ret = -EBUSY;
 
        VM_BUG_ON_PAGE(!page_count(page), page);
-       VM_BUG_ON_PAGE(PageTail(page), page);
+       WARN_RATELIMIT(PageTail(page), "trying to isolate tail page");
 
        if (PageLRU(page)) {
                struct zone *zone = page_zone(page);