1 files changed, 52 insertions, 0 deletions

diff --git a/mm/page_io.c b/mm/page_io.c
index 34f02923744c..307a3e795290 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -17,6 +17,7 @@
 #include <linux/swap.h>
 #include <linux/bio.h>
 #include <linux/swapops.h>
+#include <linux/buffer_head.h>
 #include <linux/writeback.h>
 #include <linux/frontswap.h>
 #include <asm/pgtable.h>
@@ -94,6 +95,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
 {
         struct bio *bio;
         int ret = 0, rw = WRITE;
+        struct swap_info_struct *sis = page_swap_info(page);
 
         if (try_to_free_swap(page)) {
                 unlock_page(page);
@@ -105,6 +107,32 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
                 end_page_writeback(page);
                 goto out;
         }
+
+        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 = page_address(page),
+                        .iov_len  = 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;
+
+                unlock_page(page);
+                ret = mapping->a_ops->direct_IO(KERNEL_WRITE,
+                                                &kiocb, &iov,
+                                                kiocb.ki_pos, 1);
+                if (ret == PAGE_SIZE) {
+                        count_vm_event(PSWPOUT);
+                        ret = 0;
+                }
+                return ret;
+        }
+
         bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
         if (bio == NULL) {
                 set_page_dirty(page);
@@ -126,6 +154,7 @@ int swap_readpage(struct page *page)
 {
         struct bio *bio;
         int ret = 0;
+        struct swap_info_struct *sis = page_swap_info(page);
 
         VM_BUG_ON(!PageLocked(page));
         VM_BUG_ON(PageUptodate(page));
@@ -134,6 +163,17 @@ int swap_readpage(struct page *page)
                 unlock_page(page);
                 goto out;
         }
+
+        if (sis->flags & SWP_FILE) {
+                struct file *swap_file = sis->swap_file;
+                struct address_space *mapping = swap_file->f_mapping;
+
+                ret = mapping->a_ops->readpage(swap_file, page);
+                if (!ret)
+                        count_vm_event(PSWPIN);
+                return ret;
+        }
+
         bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
         if (bio == NULL) {
                 unlock_page(page);
@@ -145,3 +185,15 @@ int swap_readpage(struct page *page)
 out:
         return ret;
 }
+
+int swap_set_page_dirty(struct page *page)
+{
+        struct swap_info_struct *sis = page_swap_info(page);
+
+        if (sis->flags & SWP_FILE) {
+                struct address_space *mapping = sis->swap_file->f_mapping;
+                return mapping->a_ops->set_page_dirty(page);
+        } else {
+                return __set_page_dirty_no_writeback(page);
+        }
+}