path: root/fs/nilfs2/page.c
diff options
authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2010-09-06 12:05:43 +0900
committerRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2010-10-23 09:24:37 +0900
commitebdfed4dc59d177cf26013a0c9b8ee9652e9a140 (patch)
tree6ef90f068ae41c55234181c93d8e30a303126c43 /fs/nilfs2/page.c
parenta8070dd365dd995f6139a2fc3aeee10159bdcc45 (diff)
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 <konishi.ryusuke@lab.ntt.co.jp>
Diffstat (limited to 'fs/nilfs2/page.c')
1 files changed, 25 insertions, 0 deletions
diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index aab11db2cb0..6384ac14c0c 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: