#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/frontswap.h>
-#include <linux/aio.h>
+#include <linux/blkdev.h>
+#include <linux/uio.h>
#include <asm/pgtable.h>
static struct bio *get_swap_bio(gfp_t gfp_flags,
bio = bio_alloc(gfp_flags, 1);
if (bio) {
- bio->bi_sector = map_swap_page(page, &bio->bi_bdev);
- bio->bi_sector <<= PAGE_SHIFT - 9;
- bio->bi_io_vec[0].bv_page = page;
- bio->bi_io_vec[0].bv_len = PAGE_SIZE;
- bio->bi_io_vec[0].bv_offset = 0;
- bio->bi_vcnt = 1;
- bio->bi_size = PAGE_SIZE;
+ bio->bi_iter.bi_sector = map_swap_page(page, &bio->bi_bdev);
+ bio->bi_iter.bi_sector <<= PAGE_SHIFT - 9;
bio->bi_end_io = end_io;
+
+ bio_add_page(bio, page, PAGE_SIZE, 0);
+ BUG_ON(bio->bi_iter.bi_size != PAGE_SIZE);
}
return bio;
}
-void end_swap_bio_write(struct bio *bio, int err)
+void end_swap_bio_write(struct bio *bio)
{
- const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct page *page = bio->bi_io_vec[0].bv_page;
- if (!uptodate) {
+ if (bio->bi_error) {
SetPageError(page);
/*
* We failed to write the page out to swap-space.
printk(KERN_ALERT "Write-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);
+ (unsigned long long)bio->bi_iter.bi_sector);
ClearPageReclaim(page);
}
end_page_writeback(page);
bio_put(bio);
}
-void end_swap_bio_read(struct bio *bio, int err)
+static void end_swap_bio_read(struct bio *bio)
{
- const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
struct page *page = bio->bi_io_vec[0].bv_page;
- if (!uptodate) {
+ if (bio->bi_error) {
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 {
- SetPageUptodate(page);
+ (unsigned long long)bio->bi_iter.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);
}
return ret;
}
+static sector_t swap_page_sector(struct page *page)
+{
+ return (sector_t)__page_file_index(page) << (PAGE_CACHE_SHIFT - 9);
+}
+
int __swap_writepage(struct page *page, struct writeback_control *wbc,
- void (*end_write_func)(struct bio *, int))
+ bio_end_io_t end_write_func)
{
struct bio *bio;
- int ret = 0, rw = WRITE;
+ int ret, rw = WRITE;
struct swap_info_struct *sis = page_swap_info(page);
if (sis->flags & SWP_FILE) {
struct kiocb kiocb;
struct file *swap_file = sis->swap_file;
struct address_space *mapping = swap_file->f_mapping;
- struct iovec iov = {
- .iov_base = kmap(page),
- .iov_len = PAGE_SIZE,
+ struct bio_vec bv = {
+ .bv_page = page,
+ .bv_len = PAGE_SIZE,
+ .bv_offset = 0
};
+ struct iov_iter from;
+ iov_iter_bvec(&from, ITER_BVEC | WRITE, &bv, 1, PAGE_SIZE);
init_sync_kiocb(&kiocb, swap_file);
kiocb.ki_pos = page_file_offset(page);
- kiocb.ki_left = PAGE_SIZE;
- kiocb.ki_nbytes = PAGE_SIZE;
set_page_writeback(page);
unlock_page(page);
- ret = mapping->a_ops->direct_IO(KERNEL_WRITE,
- &kiocb, &iov,
- kiocb.ki_pos, 1);
- kunmap(page);
+ ret = mapping->a_ops->direct_IO(&kiocb, &from, kiocb.ki_pos);
if (ret == PAGE_SIZE) {
count_vm_event(PSWPOUT);
ret = 0;
return ret;
}
+ ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, wbc);
+ if (!ret) {
+ count_vm_event(PSWPOUT);
+ return 0;
+ }
+
+ ret = 0;
bio = get_swap_bio(GFP_NOIO, page, end_write_func);
if (bio == NULL) {
set_page_dirty(page);
int ret = 0;
struct swap_info_struct *sis = page_swap_info(page);
- VM_BUG_ON(!PageLocked(page));
- VM_BUG_ON(PageUptodate(page));
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
+ VM_BUG_ON_PAGE(PageUptodate(page), page);
if (frontswap_load(page) == 0) {
SetPageUptodate(page);
unlock_page(page);
return ret;
}
+ ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
+ if (!ret) {
+ count_vm_event(PSWPIN);
+ return 0;
+ }
+
+ ret = 0;
bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
if (bio == NULL) {
unlock_page(page);
projects / firefly-linux-kernel-4.4.55.git / blobdiff