[PATCH] Direct Migration V9: Avoid writeback / page_migrate() method

Migrate a page with buffers without requiring writeback

This introduces a new address space operation migratepage() that may be used
by a filesystem to implement its own version of page migration.

A version is provided that migrates buffers attached to pages.  Some
filesystems (ext2, ext3, xfs) are modified to utilize this feature.

The swapper address space operation are modified so that a regular
migrate_page() will occur for anonymous pages without writeback (migrate_pages
forces every anonymous page to have a swap entry).

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 8824e84f8a56..3fc4238e9703 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1559,6 +1559,7 @@ static struct address_space_operations ext3_ordered_aops = {
         .invalidatepage = ext3_invalidatepage,
         .releasepage    = ext3_releasepage,
         .direct_IO      = ext3_direct_IO,
+        .migratepage    = buffer_migrate_page,
 };
 
 static struct address_space_operations ext3_writeback_aops = {
@@ -1572,6 +1573,7 @@ static struct address_space_operations ext3_writeback_aops = {
         .invalidatepage = ext3_invalidatepage,
         .releasepage    = ext3_releasepage,
         .direct_IO      = ext3_direct_IO,
+        .migratepage    = buffer_migrate_page,
 };
 
 static struct address_space_operations ext3_journalled_aops = {