nfsd4: use local variable in nfs4svc_encode_compoundres

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

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 6c0585b..84374d8 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -840,7 +840,8 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
                goto out;
        }
 
-       inc_mm_counter(vma->vm_mm, anon_rss);
+       dec_mm_counter(vma->vm_mm, MM_SWAPENTS);
+       inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
        get_page(page);
        set_pte_at(vma->vm_mm, addr, pte,
                   pte_mkold(mk_pte(page, vma->vm_page_prot)));
@@ -1759,11 +1760,11 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
        unsigned int type;
        int i, prev;
        int error;
-       union swap_header *swap_header = NULL;
-       unsigned int nr_good_pages = 0;
+       union swap_header *swap_header;
+       unsigned int nr_good_pages;
        int nr_extents = 0;
        sector_t span;
-       unsigned long maxpages = 1;
+       unsigned long maxpages;
        unsigned long swapfilepages;
        unsigned char *swap_map = NULL;
        struct page *page = NULL;
@@ -1922,9 +1923,13 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
         * swap pte.
         */
        maxpages = swp_offset(pte_to_swp_entry(
-                       swp_entry_to_pte(swp_entry(0, ~0UL)))) - 1;
-       if (maxpages > swap_header->info.last_page)
-               maxpages = swap_header->info.last_page;
+                       swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1;
+       if (maxpages > swap_header->info.last_page) {
+               maxpages = swap_header->info.last_page + 1;
+               /* p->max is an unsigned int: don't overflow it */
+               if ((unsigned int)maxpages == 0)
+                       maxpages = UINT_MAX;
+       }
        p->highest_bit = maxpages - 1;
 
        error = -EINVAL;
@@ -1948,23 +1953,24 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
        }
 
        memset(swap_map, 0, maxpages);
+       nr_good_pages = maxpages - 1;   /* omit header page */
+
        for (i = 0; i < swap_header->info.nr_badpages; i++) {
-               int page_nr = swap_header->info.badpages[i];
-               if (page_nr <= 0 || page_nr >= swap_header->info.last_page) {
+               unsigned int page_nr = swap_header->info.badpages[i];
+               if (page_nr == 0 || page_nr > swap_header->info.last_page) {
                        error = -EINVAL;
                        goto bad_swap;
                }
-               swap_map[page_nr] = SWAP_MAP_BAD;
+               if (page_nr < maxpages) {
+                       swap_map[page_nr] = SWAP_MAP_BAD;
+                       nr_good_pages--;
+               }
        }
 
        error = swap_cgroup_swapon(type, maxpages);
        if (error)
                goto bad_swap;
 
-       nr_good_pages = swap_header->info.last_page -
-                       swap_header->info.nr_badpages -
-                       1 /* header page */;
-
        if (nr_good_pages) {
                swap_map[0] = SWAP_MAP_BAD;
                p->max = maxpages;
@@ -2155,7 +2161,11 @@ void swap_shmem_alloc(swp_entry_t entry)
 }
 
 /*
- * increase reference count of swap entry by 1.
+ * Increase reference count of swap entry by 1.
+ * Returns 0 for success, or -ENOMEM if a swap_count_continuation is required
+ * but could not be atomically allocated.  Returns 0, just as if it succeeded,
+ * if __swap_duplicate() fails for another reason (-EINVAL or -ENOENT), which
+ * might occur if a page table entry has got corrupted.
  */
 int swap_duplicate(swp_entry_t entry)
 {