From ebdfed4dc59d177cf26013a0c9b8ee9652e9a140 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Mon, 6 Sep 2010 12:05:43 +0900 Subject: nilfs2: add routines to roll back state of DAT file This adds optional function to metadata files which makes a copy of bmap, page caches, and b-tree node cache, and rolls back to the copy as needed. This enhancement is intended to displace gcdat inode that provides a similar function in a different way. In this patch, nilfs_shadow_map structure is added to store a copy of the foregoing states. nilfs_mdt_setup_shadow_map relates this structure to a metadata file. And, nilfs_mdt_save_to_shadow_map() and nilfs_mdt_restore_from_shadow_map() provides save and restore functions respectively. Finally, nilfs_mdt_clear_shadow_map() clears states of nilfs_shadow_map. The copy of b-tree node cache and page cache is made by duplicating only dirty pages into corresponding caches in nilfs_shadow_map. Their restoration is done by clearing dirty pages from original caches and by copying dirty pages back from nilfs_shadow_map. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/page.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'fs/nilfs2/page.c') diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index aab11db2cb08..6384ac14c0c8 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -513,6 +513,31 @@ unsigned nilfs_page_count_clean_buffers(struct page *page, } return nc; } + +void nilfs_mapping_init_once(struct address_space *mapping) +{ + memset(mapping, 0, sizeof(*mapping)); + INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC); + spin_lock_init(&mapping->tree_lock); + INIT_LIST_HEAD(&mapping->private_list); + spin_lock_init(&mapping->private_lock); + + spin_lock_init(&mapping->i_mmap_lock); + INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap); + INIT_LIST_HEAD(&mapping->i_mmap_nonlinear); +} + +void nilfs_mapping_init(struct address_space *mapping, + struct backing_dev_info *bdi, + const struct address_space_operations *aops) +{ + mapping->host = NULL; + mapping->flags = 0; + mapping_set_gfp_mask(mapping, GFP_NOFS); + mapping->assoc_mapping = NULL; + mapping->backing_dev_info = bdi; + mapping->a_ops = aops; +} /* * NILFS2 needs clear_page_dirty() in the following two cases: -- cgit v1.2.3