* Swap reorganised 29.12.95, Stephen Tweedie
*/
-#include <linux/config.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/mman.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <linux/swapops.h>
+#include <linux/vs_base.h>
#include <linux/vs_memory.h>
DEFINE_SPINLOCK(swap_lock);
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);
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_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);
}
}
}
+#ifdef CONFIG_SOFTWARE_SUSPEND
+/*
+ * Find the swap type that corresponds to given device (if any).
+ *
+ * @offset - number of the PAGE_SIZE-sized block of the device, starting
+ * from 0, in which the swap header is expected to be located.
+ *
+ * This is needed for the suspend to disk (aka swsusp).
+ */
+int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p)
+{
+ struct block_device *bdev = NULL;
+ int i;
+
+ if (device)
+ bdev = bdget(device);
+
+ spin_lock(&swap_lock);
+ for (i = 0; i < nr_swapfiles; i++) {
+ struct swap_info_struct *sis = swap_info + i;
+
+ if (!(sis->flags & SWP_WRITEOK))
+ continue;
+
+ if (!bdev) {
+ if (bdev_p)
+ *bdev_p = sis->bdev;
+
+ spin_unlock(&swap_lock);
+ return i;
+ }
+ if (bdev == sis->bdev) {
+ struct swap_extent *se;
+
+ se = list_entry(sis->extent_list.next,
+ struct swap_extent, list);
+ if (se->start_block == offset) {
+ if (bdev_p)
+ *bdev_p = sis->bdev;
+
+ spin_unlock(&swap_lock);
+ bdput(bdev);
+ return i;
+ }
+ }
+ }
+ spin_unlock(&swap_lock);
+ if (bdev)
+ bdput(bdev);
+
+ 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_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;
}
}
+#ifdef CONFIG_SOFTWARE_SUSPEND
+/*
+ * Get the (PAGE_SIZE) block corresponding to given offset on the swapdev
+ * corresponding to given index in swap_info (swap type).
+ */
+sector_t swapdev_block(int swap_type, pgoff_t offset)
+{
+ struct swap_info_struct *sis;
+
+ if (swap_type >= nr_swapfiles)
+ return 0;
+
+ sis = swap_info + swap_type;
+ return (sis->flags & SWP_WRITEOK) ? map_swap_page(sis, offset) : 0;
+}
+#endif /* CONFIG_SOFTWARE_SUSPEND */
+
/*
* Free all of a swapdev's extent information
*/
mutex_lock(&swapon_mutex);
+ if (!l)
+ return SEQ_START_TOKEN;
+
for (i = 0; i < nr_swapfiles; i++, ptr++) {
if (!(ptr->flags & SWP_USED) || !ptr->swap_map)
continue;
- if (!l--)
+ if (!--l)
return ptr;
}
static void *swap_next(struct seq_file *swap, void *v, loff_t *pos)
{
- struct swap_info_struct *ptr = v;
+ struct swap_info_struct *ptr;
struct swap_info_struct *endptr = swap_info + nr_swapfiles;
- for (++ptr; ptr < endptr; ptr++) {
+ if (v == SEQ_START_TOKEN)
+ ptr = swap_info;
+ else {
+ ptr = v;
+ ptr++;
+ }
+
+ for (; ptr < endptr; ptr++) {
if (!(ptr->flags & SWP_USED) || !ptr->swap_map)
continue;
++*pos;
struct file *file;
int len;
- if (v == swap_info)
- seq_puts(swap, "Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
+ if (ptr == SEQ_START_TOKEN) {
+ seq_puts(swap,"Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
+ return 0;
+ }
file = ptr->swap_file;
- len = seq_path(swap, file->f_vfsmnt, file->f_dentry, " \t\n\\");
+ len = seq_path(swap, file->f_path.mnt, file->f_path.dentry, " \t\n\\");
seq_printf(swap, "%*s%s\t%u\t%u\t%d\n",
len < 40 ? 40 - len : 1, " ",
- S_ISBLK(file->f_dentry->d_inode->i_mode) ?
+ S_ISBLK(file->f_path.dentry->d_inode->i_mode) ?
"partition" : "file\t",
ptr->pages << (PAGE_SHIFT - 10),
ptr->inuse_pages << (PAGE_SHIFT - 10),
return 0;
}
-static struct seq_operations swaps_op = {
+static const struct seq_operations swaps_op = {
.start = swap_start,
.next = swap_next,
.stop = swap_stop,
return seq_open(file, &swaps_op);
}
-static struct file_operations proc_swaps_operations = {
+static const struct file_operations proc_swaps_operations = {
.open = swaps_open,
.read = seq_read,
.llseek = seq_lseek,
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;
}
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;
error = -EINVAL;
if (!maxpages)
goto bad_swap;
+ if (swapfilesize && maxpages > swapfilesize) {
+ printk(KERN_WARNING
+ "Swap area shorter than signature indicates\n");
+ goto bad_swap;
+ }
if (swap_header->info.nr_badpages && S_ISREG(inode->i_mode))
goto bad_swap;
if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES)
goto bad_swap;
}
- if (swapfilesize && maxpages > swapfilesize) {
- printk(KERN_WARNING
- "Swap area shorter than signature indicates\n");
- error = -EINVAL;
- goto bad_swap;
- }
if (nr_good_pages) {
p->swap_map[0] = SWAP_MAP_BAD;
p->max = maxpages;
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;
*/
int valid_swaphandles(swp_entry_t entry, unsigned long *offset)
{
- int ret = 0, i = 1 << page_cluster;
+ int our_page_cluster = page_cluster;
+ int ret = 0, i = 1 << our_page_cluster;
unsigned long toff;
struct swap_info_struct *swapdev = swp_type(entry) + swap_info;
- if (!page_cluster) /* no readahead */
+ if (!our_page_cluster) /* no readahead */
return 0;
- toff = (swp_offset(entry) >> page_cluster) << page_cluster;
+ toff = (swp_offset(entry) >> our_page_cluster) << our_page_cluster;
if (!toff) /* first page is swap header */
toff++, i--;
*offset = toff;
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