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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/mdt.h
parenta8070dd365dd995f6139a2fc3aeee10159bdcc45 (diff)
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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/mdt.h')
-rw-r--r--fs/nilfs2/mdt.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/nilfs2/mdt.h b/fs/nilfs2/mdt.h
index f445602..e7f0d15 100644
--- a/fs/nilfs2/mdt.h
+++ b/fs/nilfs2/mdt.h
@@ -28,6 +28,13 @@
#include "nilfs.h"
#include "page.h"
+struct nilfs_shadow_map {
+ struct nilfs_bmap_store bmap_store;
+ struct address_space frozen_data;
+ struct address_space frozen_btnodes;
+ struct list_head frozen_buffers;
+};
+
/**
* struct nilfs_mdt_info - on-memory private data of meta data files
* @mi_nilfs: back pointer to the_nilfs struct
@@ -37,6 +44,7 @@
* @mi_first_entry_offset: offset to the first entry
* @mi_entries_per_block: number of entries in a block
* @mi_palloc_cache: persistent object allocator cache
+ * @mi_shadow: shadow of bmap and page caches
* @mi_blocks_per_group: number of blocks in a group
* @mi_blocks_per_desc_block: number of blocks per descriptor block
*/
@@ -48,6 +56,7 @@ struct nilfs_mdt_info {
unsigned mi_first_entry_offset;
unsigned long mi_entries_per_block;
struct nilfs_palloc_cache *mi_palloc_cache;
+ struct nilfs_shadow_map *mi_shadow;
unsigned long mi_blocks_per_group;
unsigned long mi_blocks_per_desc_block;
};
@@ -86,6 +95,11 @@ void nilfs_mdt_destroy(struct inode *);
void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
void nilfs_mdt_set_shadow(struct inode *, struct inode *);
+int nilfs_mdt_setup_shadow_map(struct inode *inode,
+ struct nilfs_shadow_map *shadow);
+int nilfs_mdt_save_to_shadow_map(struct inode *inode);
+void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
+void nilfs_mdt_clear_shadow_map(struct inode *inode);
#define nilfs_mdt_mark_buffer_dirty(bh) nilfs_mark_buffer_dirty(bh)