Some filesystems have a synchronous readpage and an asynchronous
readahead. Call the readahead operation if we're trying to do swap
readahead.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
mm/page_io.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/mm/page_io.c b/mm/page_io.c
index e485a6e8a6cd..faf5ccb42946 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -367,6 +367,24 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
return ret;
}
+static int mapping_readpage(struct file *file, struct address_space *mapping,
+ struct page *page, bool synchronous)
+{
+ struct readahead_control ractl = {
+ .file = file,
+ .mapping = mapping,
+ ._index = page->index,
+ ._nr_pages = 1,
+ };
+
+ if (!synchronous && mapping->a_ops->readahead) {
+ mapping->a_ops->readahead(&ractl);
+ return 0;
+ }
+
+ return mapping->a_ops->readpage(file, page);
+}
+
int swap_readpage(struct page *page, bool synchronous)
{
struct bio *bio;
@@ -395,9 +413,9 @@ int swap_readpage(struct page *page, bool synchronous)
if (data_race(sis->flags & SWP_FS)) {
struct file *swap_file = sis->swap_file;
- struct address_space *mapping = swap_file->f_mapping;
- ret = mapping->a_ops->readpage(swap_file, page);
+ ret = mapping_readpage(swap_file, swap_file->f_mapping,
+ page, synchronous);
if (!ret)
count_vm_event(PSWPIN);
goto out;
--
2.28.0
