* Swap reorganised 29.12.95, Stephen Tweedie
*/
+#include <linux/config.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/mman.h>
struct swap_list_t swap_list = {-1, -1};
-static struct swap_info_struct swap_info[MAX_SWAPFILES];
+struct swap_info_struct swap_info[MAX_SWAPFILES];
static DEFINE_MUTEX(swapon_mutex);
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)) {
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_get_page(&swapper_space, entry.val);
- if (page && unlikely(TestSetPageLocked(page))) {
- page_cache_release(page);
- page = NULL;
- }
- }
+ if (swap_entry_free(p, swp_offset(entry)) == 1)
+ page = find_trylock_page(&swapper_space, entry.val);
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! */
- /* Also recheck PageSwapCache after page is locked (above) */
- if (PageSwapCache(page) && !PageWriteback(page) &&
- (one_user || vm_swap_full())) {
+ if (!PageWriteback(page) && (one_user || vm_swap_full())) {
delete_from_swap_cache(page);
SetPageDirty(page);
}
}
}
-#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[i].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
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.
*/
swap_map = &si->swap_map[i];
entry = swp_entry(type, i);
+again:
page = read_swap_cache_async(entry, NULL, 0);
if (!page) {
/*
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);
/*
while (*swap_map > 1 && !retval &&
(p = p->next) != &start_mm->mmlist) {
mm = list_entry(p, struct mm_struct, mmlist);
- if (!atomic_inc_not_zero(&mm->mm_users))
+ if (atomic_inc_return(&mm->mm_users) == 1) {
+ atomic_dec(&mm->mm_users);
continue;
+ }
spin_unlock(&mmlist_lock);
mmput(prev_mm);
prev_mm = mm;
if (!(p->flags & SWP_USED))
break;
error = -EPERM;
- if (type >= MAX_SWAPFILES) {
+ /*
+ * 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))))) {
spin_unlock(&swap_lock);
goto out;
}
error = -EINVAL;
goto bad_swap;
}
- page = read_mapping_page(mapping, 0, swap_file);
+ page = read_cache_page(mapping, 0,
+ (filler_t *)mapping->a_ops->readpage, swap_file);
if (IS_ERR(page)) {
error = PTR_ERR(page);
goto bad_swap;
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;
git://git.onelab.eu / linux-2.6.git / blobdiff