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| author | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2010-09-06 12:05:43 +0900 |
|---|---|---|
| committer | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2010-10-23 09:24:37 +0900 |
| commit | ebdfed4dc59d177cf26013a0c9b8ee9652e9a140 (patch) | |
| tree | 6ef90f068ae41c55234181c93d8e30a303126c43 /fs/nilfs2/mdt.h | |
| parent | a8070dd365dd995f6139a2fc3aeee10159bdcc45 (diff) | |
| download | linux-ebdfed4dc59d177cf26013a0c9b8ee9652e9a140.tar.bz2 | |
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.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/nilfs2/mdt.h b/fs/nilfs2/mdt.h index f44560224bd1..e7f0d158c527 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) |