Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / mm / filemap.c

diff --git a/kernel/mm/filemap.c b/kernel/mm/filemap.c
index 4430136..91dc614 100644 (file)
--- a/kernel/mm/filemap.c
+++ b/kernel/mm/filemap.c
@@ -109,6 +109,51 @@
  *   ->tasklist_lock            (memory_failure, collect_procs_ao)
  */
 
+static int page_cache_tree_insert(struct address_space *mapping,
+                                 struct page *page, void **shadowp)
+{
+       struct radix_tree_node *node;
+       void **slot;
+       int error;
+
+       error = __radix_tree_create(&mapping->page_tree, page->index,
+                                   &node, &slot);
+       if (error)
+               return error;
+       if (*slot) {
+               void *p;
+
+               p = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
+               if (!radix_tree_exceptional_entry(p))
+                       return -EEXIST;
+               if (shadowp)
+                       *shadowp = p;
+               mapping->nrshadows--;
+               if (node)
+                       workingset_node_shadows_dec(node);
+       }
+       radix_tree_replace_slot(slot, page);
+       mapping->nrpages++;
+       if (node) {
+               workingset_node_pages_inc(node);
+               /*
+                * Don't track node that contains actual pages.
+                *
+                * Avoid acquiring the list_lru lock if already
+                * untracked.  The list_empty() test is safe as
+                * node->private_list is protected by
+                * mapping->tree_lock.
+                */
+               if (!list_empty(&node->private_list)) {
+                       local_lock(workingset_shadow_lock);
+                       list_lru_del(&__workingset_shadow_nodes,
+                                    &node->private_list);
+                       local_unlock(workingset_shadow_lock);
+               }
+       }
+       return 0;
+}
+
 static void page_cache_tree_delete(struct address_space *mapping,
                                   struct page *page, void *shadow)
 {
@@ -122,6 +167,14 @@ static void page_cache_tree_delete(struct address_space *mapping,
 
        __radix_tree_lookup(&mapping->page_tree, page->index, &node, &slot);
 
+       if (!node) {
+               /*
+                * We need a node to properly account shadow
+                * entries. Don't plant any without. XXX
+                */
+               shadow = NULL;
+       }
+
        if (shadow) {
                mapping->nrshadows++;
                /*
@@ -540,9 +593,8 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
                memcg = mem_cgroup_begin_page_stat(old);
                spin_lock_irqsave(&mapping->tree_lock, flags);
                __delete_from_page_cache(old, NULL, memcg);
-               error = radix_tree_insert(&mapping->page_tree, offset, new);
+               error = page_cache_tree_insert(mapping, new, NULL);
                BUG_ON(error);
-               mapping->nrpages++;
 
                /*
                 * hugetlb pages do not participate in page cache accounting.
@@ -564,51 +616,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL_GPL(replace_page_cache_page);
 
-static int page_cache_tree_insert(struct address_space *mapping,
-                                 struct page *page, void **shadowp)
-{
-       struct radix_tree_node *node;
-       void **slot;
-       int error;
-
-       error = __radix_tree_create(&mapping->page_tree, page->index,
-                                   &node, &slot);
-       if (error)
-               return error;
-       if (*slot) {
-               void *p;
-
-               p = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
-               if (!radix_tree_exceptional_entry(p))
-                       return -EEXIST;
-               if (shadowp)
-                       *shadowp = p;
-               mapping->nrshadows--;
-               if (node)
-                       workingset_node_shadows_dec(node);
-       }
-       radix_tree_replace_slot(slot, page);
-       mapping->nrpages++;
-       if (node) {
-               workingset_node_pages_inc(node);
-               /*
-                * Don't track node that contains actual pages.
-                *
-                * Avoid acquiring the list_lru lock if already
-                * untracked.  The list_empty() test is safe as
-                * node->private_list is protected by
-                * mapping->tree_lock.
-                */
-               if (!list_empty(&node->private_list)) {
-                       local_lock(workingset_shadow_lock);
-                       list_lru_del(&__workingset_shadow_nodes,
-                                    &node->private_list);
-                       local_unlock(workingset_shadow_lock);
-               }
-       }
-       return 0;
-}
-
 static int __add_to_page_cache_locked(struct page *page,
                                      struct address_space *mapping,
                                      pgoff_t offset, gfp_t gfp_mask,
@@ -1557,6 +1564,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
 
                cond_resched();
 find_page:
+               if (fatal_signal_pending(current)) {
+                       error = -EINTR;
+                       goto out;
+               }
+
                page = find_get_page(mapping, index);
                if (!page) {
                        page_cache_sync_readahead(mapping,