nilfs2: add omitted comments for different structures in driver implementation

Add omitted comments for different structures in driver implementation.

Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nilfs2/alloc.h

@@ -76,15 +76,23 @@ int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
 #define nilfs_clear_bit_atomic		ext2_clear_bit_atomic
 #define nilfs_find_next_zero_bit	find_next_zero_bit_le
 
-/*
- * persistent object allocator cache
+/**
+ * struct nilfs_bh_assoc - block offset and buffer head association
+ * @blkoff: block offset
+ * @bh: buffer head
  */
-
 struct nilfs_bh_assoc {
 	unsigned long blkoff;
 	struct buffer_head *bh;
 };
 
+/**
+ * struct nilfs_palloc_cache - persistent object allocator cache
+ * @lock: cache protecting lock
+ * @prev_desc: blockgroup descriptors cache
+ * @prev_bitmap: blockgroup bitmap cache
+ * @prev_entry: translation entries cache
+ */
 struct nilfs_palloc_cache {
 	spinlock_t lock;
 	struct nilfs_bh_assoc prev_desc;

fs/nilfs2/bmap.h

@@ -135,6 +135,13 @@ struct nilfs_bmap {
 /* state */
 #define NILFS_BMAP_DIRTY	0x00000001
 
+/**
+ * struct nilfs_bmap_store - shadow copy of bmap state
+ * @data: cached raw block mapping of on-disk inode
+ * @last_allocated_key: cached value of last allocated key for data block
+ * @last_allocated_ptr: cached value of last allocated ptr for data block
+ * @state: cached value of state field of bmap structure
+ */
 struct nilfs_bmap_store {
 	__le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
 	__u64 last_allocated_key;

fs/nilfs2/btnode.h

@@ -29,7 +29,13 @@
 #include <linux/fs.h>
 #include <linux/backing-dev.h>
 
-
+/**
+ * struct nilfs_btnode_chkey_ctxt - change key context
+ * @oldkey: old key of block's moving content
+ * @newkey: new key for block's content
+ * @bh: buffer head of old buffer
+ * @newbh: buffer head of new buffer
+ */
 struct nilfs_btnode_chkey_ctxt {
 	__u64 oldkey;
 	__u64 newkey;

fs/nilfs2/dat.c

@@ -33,6 +33,12 @@
 #define NILFS_CNO_MIN	((__u64)1)
 #define NILFS_CNO_MAX	(~(__u64)0)
 
+/**
+ * struct nilfs_dat_info - on-memory private data of DAT file
+ * @mi: on-memory private data of metadata file
+ * @palloc_cache: persistent object allocator cache of DAT file
+ * @shadow: shadow map of DAT file
+ */
 struct nilfs_dat_info {
 	struct nilfs_mdt_info mi;
 	struct nilfs_palloc_cache palloc_cache;

fs/nilfs2/export.h

@@ -5,6 +5,14 @@
 
 extern const struct export_operations nilfs_export_ops;
 
+/**
+ * struct nilfs_fid - NILFS file id type
+ * @cno: checkpoint number
+ * @ino: inode number
+ * @gen: file generation (version) for NFS
+ * @parent_gen: parent generation (version) for NFS
+ * @parent_ino: parent inode number
+ */
 struct nilfs_fid {
 	u64 cno;
 	u64 ino;

fs/nilfs2/ifile.c

@@ -29,7 +29,11 @@
 #include "alloc.h"
 #include "ifile.h"
 
-
+/**
+ * struct nilfs_ifile_info - on-memory private data of ifile
+ * @mi: on-memory private data of metadata file
+ * @palloc_cache: persistent object allocator cache of ifile
+ */
 struct nilfs_ifile_info {
 	struct nilfs_mdt_info mi;
 	struct nilfs_palloc_cache palloc_cache;

fs/nilfs2/inode.c

@@ -34,6 +34,13 @@
 #include "cpfile.h"
 #include "ifile.h"
 
+/**
+ * struct nilfs_iget_args - arguments used during comparison between inodes
+ * @ino: inode number
+ * @cno: checkpoint number
+ * @root: pointer on NILFS root object (mounted checkpoint)
+ * @for_gc: inode for GC flag
+ */
 struct nilfs_iget_args {
 	u64 ino;
 	__u64 cno;

fs/nilfs2/mdt.h

@@ -28,6 +28,13 @@
 #include "nilfs.h"
 #include "page.h"
 
+/**
+ * struct nilfs_shadow_map - shadow mapping of meta data file
+ * @bmap_store: shadow copy of bmap state
+ * @frozen_data: shadowed dirty data pages
+ * @frozen_btnodes: shadowed dirty b-tree nodes' pages
+ * @frozen_buffers: list of frozen buffers
+ */
 struct nilfs_shadow_map {
 	struct nilfs_bmap_store bmap_store;
 	struct address_space frozen_data;

fs/nilfs2/nilfs.h

@@ -32,8 +32,21 @@
 #include "the_nilfs.h"
 #include "bmap.h"
 
-/*
- * nilfs inode data in memory
+/**
+ * struct nilfs_inode_info - nilfs inode data in memory
+ * @i_flags: inode flags
+ * @i_state: dynamic state flags
+ * @i_bmap: pointer on i_bmap_data
+ * @i_bmap_data: raw block mapping
+ * @i_xattr: <TODO>
+ * @i_dir_start_lookup: page index of last successful search
+ * @i_cno: checkpoint number for GC inode
+ * @i_btnode_cache: cached pages of b-tree nodes
+ * @i_dirty: list for connecting dirty files
+ * @xattr_sem: semaphore for extended attributes processing
+ * @i_bh: buffer contains disk inode
+ * @i_root: root object of the current filesystem tree
+ * @vfs_inode: VFS inode object
  */
 struct nilfs_inode_info {
 	__u32 i_flags;

fs/nilfs2/sufile.c

@@ -30,7 +30,13 @@
 #include "mdt.h"
 #include "sufile.h"
 
-
+/**
+ * struct nilfs_sufile_info - on-memory private data of sufile
+ * @mi: on-memory private data of metadata file
+ * @ncleansegs: number of clean segments
+ * @allocmin: lower limit of allocatable segment range
+ * @allocmax: upper limit of allocatable segment range
+ */
 struct nilfs_sufile_info {
 	struct nilfs_mdt_info mi;
 	unsigned long ncleansegs;/* number of clean segments */

fs/nilfs2/the_nilfs.h

@@ -232,9 +232,8 @@ THE_NILFS_FNS(SB_DIRTY, sb_dirty)
  * @count: refcount of this structure
  * @nilfs: nilfs object
  * @ifile: inode file
- * @root: root inode
  * @inodes_count: number of inodes
- * @blocks_count: number of blocks (Reserved)
+ * @blocks_count: number of blocks
  */
 struct nilfs_root {
 	__u64 cno;