- 2.6.17 port work build breaks, but the patch set is relativly stable

[linux-flexiantxendom0-3.2.10.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index a97db0b..e5fd538 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -14,10 +14,6 @@
 #include <linux/swap.h>
 #include <linux/vmalloc.h>
 #include <linux/pagemap.h>
-#ifdef CONFIG_KDB
-#include <linux/kdb.h>
-#include <linux/kdbprivate.h>
-#endif /* CONFIG_KDB */
 #include <linux/namei.h>
 #include <linux/shm.h>
 #include <linux/blkdev.h>
@@ -49,7 +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);
 
@@ -120,7 +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)) {
@@ -401,18 +397,24 @@ void free_swap_and_cache(swp_entry_t entry)
 
        p = swap_info_get(entry);
        if (p) {
-               if (swap_entry_free(p, swp_offset(entry)) == 1)
-                       page = find_trylock_page(&swapper_space, entry.val);
+               if (swap_entry_free(p, swp_offset(entry)) == 1) {
+                       page = find_get_page(&swapper_space, entry.val);
+                       if (page && unlikely(TestSetPageLocked(page))) {
+                               page_cache_release(page);
+                               page = NULL;
+                       }
+               }
                spin_unlock(&swap_lock);
        }
        if (page) {
                int one_user;
 
                BUG_ON(PagePrivate(page));
-               page_cache_get(page);
                one_user = (page_count(page) == 2);
                /* Only cache user (+us), or swap space full? Free it! */
-               if (!PageWriteback(page) && (one_user || vm_swap_full())) {
+               /* Also recheck PageSwapCache after page is locked (above) */
+               if (PageSwapCache(page) && !PageWriteback(page) &&
+                                       (one_user || vm_swap_full())) {
                        delete_from_swap_cache(page);
                        SetPageDirty(page);
                }
@@ -421,6 +423,61 @@ 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
@@ -1640,24 +1697,6 @@ void si_swapinfo(struct sysinfo *val)
        spin_unlock(&swap_lock);
 }
 
-#ifdef CONFIG_KDB
-/* Like si_swapinfo() but without the locks */
-void kdb_si_swapinfo(struct sysinfo *val)
-{
-       unsigned int i;
-       unsigned long nr_to_be_unused = 0;
-
-       for (i = 0; i < nr_swapfiles; i++) {
-               if (!(swap_info[i].flags & SWP_USED) ||
-                    (swap_info[i].flags & SWP_WRITEOK))
-                       continue;
-               nr_to_be_unused += swap_info[i].inuse_pages;
-       }
-       val->freeswap = nr_swap_pages + nr_to_be_unused;
-       val->totalswap = total_swap_pages + nr_to_be_unused;
-}
-#endif /* CONFIG_KDB */
-
 /*
  * Verify that a swap entry is valid and increment its swap map count.
  *