string: factorize skip_spaces and export it to be generally available

[safe/jmp/linux-2.6] / mm / page_io.c

diff --git a/mm/page_io.c b/mm/page_io.c
index 667c76d..a19af95 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -19,20 +19,15 @@
 #include <linux/writeback.h>
 #include <asm/pgtable.h>
 
-static struct bio *get_swap_bio(unsigned int __nocast gfp_flags, pgoff_t index,
+static struct bio *get_swap_bio(gfp_t gfp_flags,
                                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 = { .val = index, };
-
-               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;
+               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;
@@ -44,38 +39,49 @@ static struct bio *get_swap_bio(unsigned int __nocast gfp_flags, pgoff_t index,
        return bio;
 }
 
-static int end_swap_bio_write(struct bio *bio, unsigned int bytes_done, int err)
+static void end_swap_bio_write(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 (bio->bi_size)
-               return 1;
-
-       if (!uptodate)
+       if (!uptodate) {
                SetPageError(page);
+               /*
+                * We failed to write the page out to swap-space.
+                * Re-dirty the page in order to avoid it being reclaimed.
+                * Also print a dire warning that things will go BAD (tm)
+                * very quickly.
+                *
+                * Also clear PG_reclaim to avoid rotate_reclaimable_page()
+                */
+               set_page_dirty(page);
+               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);
+               ClearPageReclaim(page);
+       }
        end_page_writeback(page);
        bio_put(bio);
-       return 0;
 }
 
-static int end_swap_bio_read(struct bio *bio, unsigned int bytes_done, int err)
+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 (bio->bi_size)
-               return 1;
-
        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 {
                SetPageUptodate(page);
        }
        unlock_page(page);
        bio_put(bio);
-       return 0;
 }
 
 /*
@@ -87,11 +93,11 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
        struct bio *bio;
        int ret = 0, rw = WRITE;
 
-       if (remove_exclusive_swap_page(page)) {
+       if (try_to_free_swap(page)) {
                unlock_page(page);
                goto out;
        }
-       bio = get_swap_bio(GFP_NOIO, page->private, page, end_swap_bio_write);
+       bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
        if (bio == NULL) {
                set_page_dirty(page);
                unlock_page(page);
@@ -99,8 +105,8 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
                goto out;
        }
        if (wbc->sync_mode == WB_SYNC_ALL)
-               rw |= (1 << BIO_RW_SYNC);
-       inc_page_state(pswpout);
+               rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
+       count_vm_event(PSWPOUT);
        set_page_writeback(page);
        unlock_page(page);
        submit_bio(rw, bio);
@@ -108,53 +114,21 @@ out:
        return ret;
 }
 
-int swap_readpage(struct file *file, struct page *page)
+int swap_readpage(struct page *page)
 {
        struct bio *bio;
        int ret = 0;
 
-       BUG_ON(!PageLocked(page));
-       ClearPageUptodate(page);
-       bio = get_swap_bio(GFP_KERNEL, page->private, page, end_swap_bio_read);
+       VM_BUG_ON(!PageLocked(page));
+       VM_BUG_ON(PageUptodate(page));
+       bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
        if (bio == NULL) {
                unlock_page(page);
                ret = -ENOMEM;
                goto out;
        }
-       inc_page_state(pswpin);
+       count_vm_event(PSWPIN);
        submit_bio(READ, bio);
 out:
        return ret;
 }
-
-#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)
-{
-       struct bio *bio;
-       int ret = 0;
-
-       lock_page(page);
-
-       bio = get_swap_bio(GFP_KERNEL, entry.val, page, end_swap_bio_read);
-       if (bio == NULL) {
-               unlock_page(page);
-               ret = -ENOMEM;
-               goto out;
-       }
-
-       submit_bio(rw | (1 << BIO_RW_SYNC), bio);
-       wait_on_page_locked(page);
-
-       if (!PageUptodate(page) || PageError(page))
-               ret = -EIO;
-out:
-       return ret;
-}
-#endif