mempolicy: rework mempolicy Reference Counting [yet again]

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

diff --git a/mm/shmem.c b/mm/shmem.c
index 5326876..0b591c6 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1187,16 +1187,19 @@ static void shmem_show_mpol(struct seq_file *seq, unsigned short policy,
 static struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp,
                        struct shmem_inode_info *info, unsigned long idx)
 {
+       struct mempolicy mpol, *spol;
        struct vm_area_struct pvma;
        struct page *page;
 
+       spol = mpol_cond_copy(&mpol,
+                               mpol_shared_policy_lookup(&info->policy, idx));
+
        /* Create a pseudo vma that just contains the policy */
        pvma.vm_start = 0;
        pvma.vm_pgoff = idx;
        pvma.vm_ops = NULL;
-       pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
+       pvma.vm_policy = spol;
        page = swapin_readahead(entry, gfp, &pvma, 0);
-       mpol_put(pvma.vm_policy);
        return page;
 }
 
@@ -1204,16 +1207,17 @@ static struct page *shmem_alloc_page(gfp_t gfp,
                        struct shmem_inode_info *info, unsigned long idx)
 {
        struct vm_area_struct pvma;
-       struct page *page;
 
        /* Create a pseudo vma that just contains the policy */
        pvma.vm_start = 0;
        pvma.vm_pgoff = idx;
        pvma.vm_ops = NULL;
        pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
-       page = alloc_page_vma(gfp, &pvma, 0);
-       mpol_put(pvma.vm_policy);
-       return page;
+
+       /*
+        * alloc_page_vma() will drop the shared policy reference
+        */
+       return alloc_page_vma(gfp, &pvma, 0);
 }
 #else /* !CONFIG_NUMA */
 #ifdef CONFIG_TMPFS