void end_swap_bio_read(struct bio *bio, int err)
{
const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct page *page = bio->bi_io_vec[0].bv_page;
if (!uptodate) {
SetPageError(page);
ClearPageUptodate(page);
printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
imajor(bio->bi_bdev->bd_inode),
iminor(bio->bi_bdev->bd_inode),
(unsigned long long)bio->bi_sector);
} else {
/*
* There is no reason to keep both uncompressed data and
* compressed data in memory.
*/
struct swap_info_struct *sis;
SetPageUptodate(page);
sis = page_swap_info(page);
if (sis->flags & SWP_BLKDEV) {
struct gendisk *disk = sis->bdev->bd_disk;
if (disk->fops->swap_slot_free_notify) {
swp_entry_t entry;
unsigned long offset;
entry.val = page_private(page);
offset = swp_offset(entry);
SetPageDirty(page);
disk->fops->swap_slot_free_notify(sis->bdev,
offset);
}
}
}
unlock_page(page);
bio_put(bio);
}
static void swap_slot_free_notify(struct page *page)
{
struct swap_info_struct *sis;
struct gendisk *disk;
/*
* There is no guarantee that the page is in swap cache - the software
* suspend code (at least) uses end_swap_bio_read() against a non-
* swapcache page. So we must check PG_swapcache before proceeding with
* this optimization.
*/
if (unlikely(!PageSwapCache(page)))
return;
sis = page_swap_info(page);
if (!(sis->flags & SWP_BLKDEV))
return;
/*
* The swap subsystem performs lazy swap slot freeing,
* expecting that the page will be swapped out again.
* So we can avoid an unnecessary write if the page
* isn't redirtied.
* This is good for real swap storage because we can
* reduce unnecessary I/O and enhance wear-leveling
* if an SSD is used as the as swap device.
* But if in-memory swap device (eg zram) is used,
* this causes a duplicated copy between uncompressed
* data in VM-owned memory and compressed data in
* zram-owned memory. So let's free zram-owned memory
* and make the VM-owned decompressed page *dirty*,
* so the page should be swapped out somewhere again if
* we again wish to reclaim it.
*/
disk = sis->bdev->bd_disk;
if (disk->fops->swap_slot_free_notify) {
swp_entry_t entry;
unsigned long offset;
<<<<<<< HEAD
int __swap_writepage(struct page *page, struct writeback_control *wbc,
void (*end_write_func)(struct bio *, int))
{
struct bio *bio;
int ret = 0, rw = WRITE;
struct swap_info_struct *sis = page_swap_info(page);
bio = get_swap_bio(GFP_NOIO, page, end_write_func);
if (bio == NULL) {
set_page_dirty(page);
unlock_page(page);
ret = -ENOMEM;
goto out;
}
if (wbc->sync_mode == WB_SYNC_ALL)
rw |= REQ_SYNC;
count_vm_event(PSWPOUT);
set_page_writeback(page);
unlock_page(page);
submit_bio(rw, bio);
out:
return ret;
}
void end_swap_bio_read(struct bio *bio, int err)
{
const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct page *page = bio->bi_io_vec[0].bv_page;
if (!uptodate) {
SetPageError(page);
ClearPageUptodate(page);
printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
imajor(bio->bi_bdev->bd_inode),
iminor(bio->bi_bdev->bd_inode),
(unsigned long long)bio->bi_sector);
goto out;
}
SetPageUptodate(page);
/*
* There is no guarantee that the page is in swap cache - the software
* suspend code (at least) uses end_swap_bio_read() against a non-
* swapcache page. So we must check PG_swapcache before proceeding with
* this optimization.
*/
if (likely(PageSwapCache(page))) {
struct swap_info_struct *sis;
sis = page_swap_info(page);
if (sis->flags & SWP_BLKDEV) {
/*
* The swap subsystem performs lazy swap slot freeing,
* expecting that the page will be swapped out again.
* So we can avoid an unnecessary write if the page
* isn't redirtied.
* This is good for real swap storage because we can
* reduce unnecessary I/O and enhance wear-leveling
* if an SSD is used as the as swap device.
* But if in-memory swap device (eg zram) is used,
* this causes a duplicated copy between uncompressed
* data in VM-owned memory and compressed data in
* zram-owned memory. So let's free zram-owned memory
* and make the VM-owned decompressed page *dirty*,
* so the page should be swapped out somewhere again if
* we again wish to reclaim it.
*/
struct gendisk *disk = sis->bdev->bd_disk;
if (disk->fops->swap_slot_free_notify) {
swp_entry_t entry;
unsigned long offset;
entry.val = page_private(page);
offset = swp_offset(entry);
SetPageDirty(page);
disk->fops->swap_slot_free_notify(sis->bdev,
offset);
}
}
}
out:
unlock_page(page);
bio_put(bio);
}