mm/shmem: add __rcu annotations and properly deref radix entry

[linux-2.6-microblaze.git] / mm / shmem.c

diff --git a/mm/shmem.c b/mm/shmem.c
index 9d6c7e5..54bec60 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -327,7 +327,7 @@ static int shmem_radix_tree_replace(struct address_space *mapping,
                        pgoff_t index, void *expected, void *replacement)
 {
        struct radix_tree_node *node;
-       void **pslot;
+       void __rcu **pslot;
        void *item;
 
        VM_BUG_ON(!expected);
@@ -395,7 +395,7 @@ static bool shmem_confirm_swap(struct address_space *mapping,
 #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
 /* ifdef here to avoid bloating shmem.o when not necessary */
 
-int shmem_huge __read_mostly;
+static int shmem_huge __read_mostly;
 
 #if defined(CONFIG_SYSFS) || defined(CONFIG_TMPFS)
 static int shmem_parse_huge(const char *str)
@@ -682,7 +682,7 @@ unsigned long shmem_partial_swap_usage(struct address_space *mapping,
                                                pgoff_t start, pgoff_t end)
 {
        struct radix_tree_iter iter;
-       void **slot;
+       void __rcu **slot;
        struct page *page;
        unsigned long swapped = 0;
 
@@ -1098,13 +1098,19 @@ static void shmem_evict_inode(struct inode *inode)
 static unsigned long find_swap_entry(struct radix_tree_root *root, void *item)
 {
        struct radix_tree_iter iter;
-       void **slot;
+       void __rcu **slot;
        unsigned long found = -1;
        unsigned int checked = 0;
 
        rcu_read_lock();
        radix_tree_for_each_slot(slot, root, &iter, 0) {
-               if (*slot == item) {
+               void *entry = radix_tree_deref_slot(slot);
+
+               if (radix_tree_deref_retry(entry)) {
+                       slot = radix_tree_iter_retry(&iter);
+                       continue;
+               }
+               if (entry == item) {
                        found = iter.index;
                        break;
                }
@@ -1322,9 +1328,6 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
        if (!swap.val)
                goto redirty;
 
-       if (mem_cgroup_try_charge_swap(page, swap))
-               goto free_swap;
-
        /*
         * Add inode to shmem_unuse()'s list of swapped-out inodes,
         * if it's not already there.  Do it now before the page is
@@ -1353,7 +1356,6 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
        }
 
        mutex_unlock(&shmem_swaplist_mutex);
-free_swap:
        put_swap_page(page, swap);
 redirty:
        set_page_dirty(page);
@@ -2626,7 +2628,7 @@ static loff_t shmem_file_llseek(struct file *file, loff_t offset, int whence)
 static void shmem_tag_pins(struct address_space *mapping)
 {
        struct radix_tree_iter iter;
-       void **slot;
+       void __rcu **slot;
        pgoff_t start;
        struct page *page;
 
@@ -2668,7 +2670,7 @@ static void shmem_tag_pins(struct address_space *mapping)
 static int shmem_wait_for_pins(struct address_space *mapping)
 {
        struct radix_tree_iter iter;
-       void **slot;
+       void __rcu **slot;
        pgoff_t start;
        struct page *page;
        int error, scan;