Signed-off-by: Jody McIntyre <scjody@modernduck.com>

[pandora-kernel.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index f1e69c3..39aa9d1 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -45,7 +45,7 @@ static const char Unused_offset[] = "Unused swap offset entry ";
 
 struct swap_list_t swap_list = {-1, -1};
 
-struct swap_info_struct swap_info[MAX_SWAPFILES];
+static struct swap_info_struct swap_info[MAX_SWAPFILES];
 
 static DEFINE_MUTEX(swapon_mutex);
 
@@ -116,7 +116,7 @@ static inline unsigned long scan_swap_map(struct swap_info_struct *si)
                                last_in_cluster = offset + SWAPFILE_CLUSTER;
                        else if (offset == last_in_cluster) {
                                spin_lock(&swap_lock);
-                               si->cluster_next = offset-SWAPFILE_CLUSTER-1;
+                               si->cluster_next = offset-SWAPFILE_CLUSTER+1;
                                goto cluster;
                        }
                        if (unlikely(--latency_ration < 0)) {
@@ -417,6 +417,61 @@ void free_swap_and_cache(swp_entry_t entry)
        }
 }
 
+#ifdef CONFIG_SOFTWARE_SUSPEND
+/*
+ * Find the swap type that corresponds to given device (if any)
+ *
+ * This is needed for software suspend and is done in such a way that inode
+ * aliasing is allowed.
+ */
+int swap_type_of(dev_t device)
+{
+       int i;
+
+       spin_lock(&swap_lock);
+       for (i = 0; i < nr_swapfiles; i++) {
+               struct inode *inode;
+
+               if (!(swap_info[i].flags & SWP_WRITEOK))
+                       continue;
+               if (!device) {
+                       spin_unlock(&swap_lock);
+                       return i;
+               }
+               inode = swap_info->swap_file->f_dentry->d_inode;
+               if (S_ISBLK(inode->i_mode) &&
+                   device == MKDEV(imajor(inode), iminor(inode))) {
+                       spin_unlock(&swap_lock);
+                       return i;
+               }
+       }
+       spin_unlock(&swap_lock);
+       return -ENODEV;
+}
+
+/*
+ * Return either the total number of swap pages of given type, or the number
+ * of free pages of that type (depending on @free)
+ *
+ * This is needed for software suspend
+ */
+unsigned int count_swap_pages(int type, int free)
+{
+       unsigned int n = 0;
+
+       if (type < nr_swapfiles) {
+               spin_lock(&swap_lock);
+               if (swap_info[type].flags & SWP_WRITEOK) {
+                       n = swap_info[type].pages;
+                       if (free)
+                               n -= swap_info[type].inuse_pages;
+               }
+               spin_unlock(&swap_lock);
+       }
+       return n;
+}
+#endif
+
 /*
  * No need to decide whether this PTE shares the swap entry with others,
  * just let do_wp_page work it out if a write is requested later - to
@@ -554,6 +609,15 @@ static int unuse_mm(struct mm_struct *mm,
        return 0;
 }
 
+#ifdef CONFIG_MIGRATION
+int remove_vma_swap(struct vm_area_struct *vma, struct page *page)
+{
+       swp_entry_t entry = { .val = page_private(page) };
+
+       return unuse_vma(vma, entry, page);
+}
+#endif
+
 /*
  * Scan swap_map from current position to next entry still in use.
  * Recycle to start on reaching the end, returning 0 when empty.
@@ -646,6 +710,7 @@ static int try_to_unuse(unsigned int type)
                 */
                swap_map = &si->swap_map[i];
                entry = swp_entry(type, i);
+again:
                page = read_swap_cache_async(entry, NULL, 0);
                if (!page) {
                        /*
@@ -680,6 +745,12 @@ static int try_to_unuse(unsigned int type)
                wait_on_page_locked(page);
                wait_on_page_writeback(page);
                lock_page(page);
+               if (!PageSwapCache(page)) {
+                       /* Page migration has occured */
+                       unlock_page(page);
+                       page_cache_release(page);
+                       goto again;
+               }
                wait_on_page_writeback(page);
 
                /*