Fix up the rw_swap_page_sync() gorrors by fully decoupling this function
from the VM - it is now just a helper function which reads a page from or
writes a page to swap.
---
25-akpm/mm/page_io.c | 48 +++++++++++++++++++++---------------------------
1 files changed, 21 insertions(+), 27 deletions(-)
diff -puN mm/page_io.c~rw_swap_page_sync-fixes mm/page_io.c
--- 25/mm/page_io.c~rw_swap_page_sync-fixes Fri Apr 9 13:54:29 2004
+++ 25-akpm/mm/page_io.c Fri Apr 9 14:01:56 2004
@@ -19,20 +19,17 @@
#include <linux/writeback.h>
#include <asm/pgtable.h>
-static struct bio *
-get_swap_bio(int gfp_flags, struct page *page, bio_end_io_t end_io)
+static struct bio *get_swap_bio(int gfp_flags, pgoff_t index,
+ struct page *page, bio_end_io_t end_io)
{
struct bio *bio;
bio = bio_alloc(gfp_flags, 1);
if (bio) {
struct swap_info_struct *sis;
- swp_entry_t entry;
+ swp_entry_t entry = { .val = index, };
- BUG_ON(!PageSwapCache(page));
- entry.val = page->private;
sis = get_swap_info_struct(swp_type(entry));
-
bio->bi_sector = map_swap_page(sis, swp_offset(entry)) *
(PAGE_SIZE >> 9);
bio->bi_bdev = sis->bdev;
@@ -94,7 +91,7 @@ int swap_writepage(struct page *page, st
unlock_page(page);
goto out;
}
- bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
+ bio = get_swap_bio(GFP_NOIO, page->private, page, end_swap_bio_write);
if (bio == NULL) {
set_page_dirty(page);
unlock_page(page);
@@ -118,7 +115,7 @@ int swap_readpage(struct file *file, str
BUG_ON(!PageLocked(page));
ClearPageUptodate(page);
- bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
+ bio = get_swap_bio(GFP_KERNEL, page->private, page, end_swap_bio_read);
if (bio == NULL) {
unlock_page(page);
ret = -ENOMEM;
@@ -131,36 +128,33 @@ out:
}
#if defined(CONFIG_SOFTWARE_SUSPEND) || defined(CONFIG_PM_DISK)
-
/*
* A scruffy utility function to read or write an arbitrary swap page
* and wait on the I/O. The caller must have a ref on the page.
+ *
+ * We use end_swap_bio_read() even for writes, because it happens to do what
+ * we want.
*/
int rw_swap_page_sync(int rw, swp_entry_t entry, struct page *page)
{
- int ret;
- unsigned long save_private;
- struct writeback_control swap_wbc = {
- .sync_mode = WB_SYNC_ALL,
- };
+ struct bio *bio;
+ int ret = 0;
lock_page(page);
- SetPageSwapCache(page);
- save_private = page->private;
- page->private = entry.val;
-
- if (rw == READ) {
- ret = swap_readpage(NULL, page);
- wait_on_page_locked(page);
- } else {
- ret = swap_writepage(page, &swap_wbc);
- wait_on_page_writeback(page);
+
+ bio = get_swap_bio(GFP_KERNEL, entry.val, page, end_swap_bio_read);
+ if (bio == NULL) {
+ unlock_page(page);
+ ret = -ENOMEM;
+ goto out;
}
- ClearPageSwapCache(page);
- page->private = save_private;
- if (ret == 0 && (!PageUptodate(page) || PageError(page)))
+ submit_bio(rw | (1 << BIO_RW_SYNC), bio);
+ wait_on_page_locked(page);
+
+ if (!PageUptodate(page) || PageError(page))
ret = -EIO;
+out:
return ret;
}
#endif
_