This adds specific functions to manage NAT pages, a cache for NAT entries, free
nids, direct/indirect node blocks for indexing data, and address space for node
pages.
- The key information of an NAT entry consists of a node id and a block address.
- An NAT page is composed of block addresses covered by a certain range of NAT
entries, which is maintained by the address space of meta_inode.
- A radix tree structure is used to cache NAT entries. The index for the tree
is a node id.
- When there is no free nid, F2FS should scan NAT entries to find new one. In
order to avoid scanning frequently, F2FS manages a list containing a number of
free nids in memory. Only when free nids in the list are exhausted, scanning
process, build_free_nids(), is triggered.
- F2FS has direct and indirect node blocks for indexing data. This patch adds
fuctions related to the node block management such as getting, allocating, and
truncating node blocks to index data.
- In order to cache node blocks in memory, F2FS has a node_inode with an address
space for node pages. This patch also adds the address space operations for
node_inode.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This adds functions required by the checkpoint operations.
Basically, f2fs adopts a roll-back model with checkpoint blocks written in the
CP area. The checkpoint procedure includes as follows.
- write_checkpoint()
1. block_operations() freezes VFS calls.
2. submit cached bios.
3. flush_nat_entries() writes NAT pages updated by dirty NAT entries.
4. flush_sit_entries() writes SIT pages updated by dirty SIT entries.
5. do_checkpoint() writes,
- checkpoint block (#0)
- orphan inode blocks
- summary blocks made by active logs
- checkpoint block (copy of #0)
6. unblock_opeations()
In order to provide an address space for meta pages, f2fs_sb_info has a special
inode, namely meta_inode. This patch also adds the address space operations for
meta_inode.
Signed-off-by: Chul Lee <chur.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This adds the implementation of superblock operations for f2fs, which includes
- init_f2fs_fs/exit_f2fs_fs
- f2fs_mount
- super_operations of f2fs
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This adds the following major in-memory structures in f2fs.
- f2fs_sb_info:
contains f2fs-specific information, two special inode pointers for node and
meta address spaces, and orphan inode management.
- f2fs_inode_info:
contains vfs_inode and other fs-specific information.
- f2fs_nm_info:
contains node manager information such as NAT entry cache, free nid list,
and NAT page management.
- f2fs_node_info:
represents a node as node id, inode number, block address, and its version.
- f2fs_sm_info:
contains segment manager information such as SIT entry cache, free segment
map, current active logs, dirty segment management, and segment utilization.
The specific structures are sit_info, free_segmap_info, dirty_seglist_info,
curseg_info.
In addition, add F2FS_SUPER_MAGIC in magic.h.
Signed-off-by: Chul Lee <chur.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
