ksm: stable_node point to page and back

[safe/jmp/linux-2.6] / mm / shmem.c

diff --git a/mm/shmem.c b/mm/shmem.c
index ccf446a..4fb41c8 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -218,7 +218,7 @@ static const struct file_operations shmem_file_operations;
 static const struct inode_operations shmem_inode_operations;
 static const struct inode_operations shmem_dir_inode_operations;
 static const struct inode_operations shmem_special_inode_operations;
-static struct vm_operations_struct shmem_vm_ops;
+static const struct vm_operations_struct shmem_vm_ops;
 
 static struct backing_dev_info shmem_backing_dev_info  __read_mostly = {
        .ra_pages       = 0,    /* No readahead */
@@ -1017,7 +1017,14 @@ int shmem_unuse(swp_entry_t entry, struct page *page)
                        goto out;
        }
        mutex_unlock(&shmem_swaplist_mutex);
-out:   return found;   /* 0 or 1 or -ENOMEM */
+       /*
+        * Can some race bring us here?  We've been holding page lock,
+        * so I think not; but would rather try again later than BUG()
+        */
+       unlock_page(page);
+       page_cache_release(page);
+out:
+       return (found < 0) ? found : 0;
 }
 
 /*
@@ -1080,7 +1087,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
                else
                        inode = NULL;
                spin_unlock(&info->lock);
-               swap_duplicate(swap);
+               swap_shmem_alloc(swap);
                BUG_ON(page_mapped(page));
                page_cache_release(page);       /* pagecache ref */
                swap_writepage(page, wbc);
@@ -2498,7 +2505,7 @@ static const struct super_operations shmem_ops = {
        .put_super      = shmem_put_super,
 };
 
-static struct vm_operations_struct shmem_vm_ops = {
+static const struct vm_operations_struct shmem_vm_ops = {
        .fault          = shmem_fault,
 #ifdef CONFIG_NUMA
        .set_policy     = shmem_set_policy,