Merge ../linus

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

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 39aa9d1..f1f5ec7 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -5,7 +5,6 @@
  *  Swap reorganised 29.12.95, Stephen Tweedie
  */
 
-#include <linux/config.h>
 #include <linux/mm.h>
 #include <linux/hugetlb.h>
 #include <linux/mman.h>
@@ -395,20 +394,29 @@ void free_swap_and_cache(swp_entry_t entry)
        struct swap_info_struct * p;
        struct page *page = NULL;
 
+       if (is_migration_entry(entry))
+               return;
+
        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);
                }
@@ -434,11 +442,12 @@ int swap_type_of(dev_t device)
 
                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;
+               inode = swap_info[i].swap_file->f_dentry->d_inode;
                if (S_ISBLK(inode->i_mode) &&
                    device == MKDEV(imajor(inode), iminor(inode))) {
                        spin_unlock(&swap_lock);
@@ -609,15 +618,6 @@ 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.
@@ -710,7 +710,6 @@ 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) {
                        /*
@@ -745,12 +744,6 @@ again:
                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);
 
                /*
@@ -779,10 +772,8 @@ again:
                        while (*swap_map > 1 && !retval &&
                                        (p = p->next) != &start_mm->mmlist) {
                                mm = list_entry(p, struct mm_struct, mmlist);
-                               if (atomic_inc_return(&mm->mm_users) == 1) {
-                                       atomic_dec(&mm->mm_users);
+                               if (!atomic_inc_not_zero(&mm->mm_users))
                                        continue;
-                               }
                                spin_unlock(&mmlist_lock);
                                mmput(prev_mm);
                                prev_mm = mm;
@@ -1401,19 +1392,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                if (!(p->flags & SWP_USED))
                        break;
        error = -EPERM;
-       /*
-        * Test if adding another swap device is possible. There are
-        * two limiting factors: 1) the number of bits for the swap
-        * type swp_entry_t definition and 2) the number of bits for
-        * the swap type in the swap ptes as defined by the different
-        * architectures. To honor both limitations a swap entry
-        * with swap offset 0 and swap type ~0UL is created, encoded
-        * to a swap pte, decoded to a swp_entry_t again and finally
-        * the swap type part is extracted. This will mask all bits
-        * from the initial ~0UL that can't be encoded in either the
-        * swp_entry_t or the architecture definition of a swap pte.
-        */
-       if (type > swp_type(pte_to_swp_entry(swp_entry_to_pte(swp_entry(~0UL,0))))) {
+       if (type >= MAX_SWAPFILES) {
                spin_unlock(&swap_lock);
                goto out;
        }
@@ -1498,8 +1477,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                error = -EINVAL;
                goto bad_swap;
        }
-       page = read_cache_page(mapping, 0,
-                       (filler_t *)mapping->a_ops->readpage, swap_file);
+       page = read_mapping_page(mapping, 0, swap_file);
        if (IS_ERR(page)) {
                error = PTR_ERR(page);
                goto bad_swap;
@@ -1703,6 +1681,9 @@ int swap_duplicate(swp_entry_t entry)
        unsigned long offset, type;
        int result = 0;
 
+       if (is_migration_entry(entry))
+               return 1;
+
        type = swp_type(entry);
        if (type >= nr_swapfiles)
                goto bad_file;