nilfs2: record used amount of each checkpoint in checkpoint list

This records the number of used blocks per checkpoint in each
checkpoint entry of cpfile.  Even though userland tools can get the
block count via nilfs_get_cpinfo ioctl, it was not updated by the
nilfs2 kernel code.  This fixes the issue and makes it available for
userland tools to calculate used amount per checkpoint.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Jiro SEKIBA <jir@unicus.jp>

fs/nilfs2/bmap.c

@@ -425,17 +425,6 @@ int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
 /*
  * Internal use only
  */
-
-void nilfs_bmap_add_blocks(const struct nilfs_bmap *bmap, int n)
-{
-	inode_add_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
-}
-
-void nilfs_bmap_sub_blocks(const struct nilfs_bmap *bmap, int n)
-{
-	inode_sub_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
-}
-
 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
 			      const struct buffer_head *bh)
 {

fs/nilfs2/bmap.h

@@ -240,9 +240,6 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
 
-void nilfs_bmap_add_blocks(const struct nilfs_bmap *, int);
-void nilfs_bmap_sub_blocks(const struct nilfs_bmap *, int);
-
 
 /* Assume that bmap semaphore is locked. */
 static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)

fs/nilfs2/btree.c

@@ -1174,7 +1174,7 @@ static int nilfs_btree_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr)
 	if (ret < 0)
 		goto out;
 	nilfs_btree_commit_insert(btree, path, level, key, ptr);
-	nilfs_bmap_add_blocks(btree, stats.bs_nblocks);
+	nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
 
  out:
 	nilfs_btree_free_path(path);
@@ -1511,7 +1511,7 @@ static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key)
 	if (ret < 0)
 		goto out;
 	nilfs_btree_commit_delete(btree, path, level, dat);
-	nilfs_bmap_sub_blocks(btree, stats.bs_nblocks);
+	nilfs_inode_sub_blocks(btree->b_inode, stats.bs_nblocks);
 
 out:
 	nilfs_btree_free_path(path);
@@ -1776,7 +1776,7 @@ int nilfs_btree_convert_and_insert(struct nilfs_bmap *btree,
 		return ret;
 	nilfs_btree_commit_convert_and_insert(btree, key, ptr, keys, ptrs, n,
 					      di, ni, bh);
-	nilfs_bmap_add_blocks(btree, stats.bs_nblocks);
+	nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
 	return 0;
 }
 

fs/nilfs2/direct.c

@@ -146,7 +146,7 @@ static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 		if (NILFS_BMAP_USE_VBN(bmap))
 			nilfs_bmap_set_target_v(bmap, key, req.bpr_ptr);
 
-		nilfs_bmap_add_blocks(bmap, 1);
+		nilfs_inode_add_blocks(bmap->b_inode, 1);
 	}
 	return ret;
 }
@@ -168,7 +168,7 @@ static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 	if (!ret) {
 		nilfs_bmap_commit_end_ptr(bmap, &req, dat);
 		nilfs_direct_set_ptr(bmap, key, NILFS_BMAP_INVALID_PTR);
-		nilfs_bmap_sub_blocks(bmap, 1);
+		nilfs_inode_sub_blocks(bmap->b_inode, 1);
 	}
 	return ret;
 }

fs/nilfs2/inode.c

@@ -41,6 +41,24 @@ struct nilfs_iget_args {
 	int for_gc;
 };
 
+void nilfs_inode_add_blocks(struct inode *inode, int n)
+{
+	struct nilfs_root *root = NILFS_I(inode)->i_root;
+
+	inode_add_bytes(inode, (1 << inode->i_blkbits) * n);
+	if (root)
+		atomic_add(n, &root->blocks_count);
+}
+
+void nilfs_inode_sub_blocks(struct inode *inode, int n)
+{
+	struct nilfs_root *root = NILFS_I(inode)->i_root;
+
+	inode_sub_bytes(inode, (1 << inode->i_blkbits) * n);
+	if (root)
+		atomic_sub(n, &root->blocks_count);
+}
+
 /**
  * nilfs_get_block() - get a file block on the filesystem (callback function)
  * @inode - inode struct of the target file

fs/nilfs2/nilfs.h

@@ -251,6 +251,8 @@ int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *, struct nilfs_argv *,
 				       void **);
 
 /* inode.c */
+void nilfs_inode_add_blocks(struct inode *inode, int n);
+void nilfs_inode_sub_blocks(struct inode *inode, int n);
 extern struct inode *nilfs_new_inode(struct inode *, int);
 extern void nilfs_free_inode(struct inode *);
 extern int nilfs_get_block(struct inode *, sector_t, struct buffer_head *, int);

include/linux/nilfs2_fs.h

@@ -216,8 +216,10 @@ struct nilfs_super_block {
  * If there is a bit set in the incompatible feature set that the kernel
  * doesn't know about, it should refuse to mount the filesystem.
  */
+#define NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT	0x00000001ULL
+
 #define NILFS_FEATURE_COMPAT_SUPP	0ULL
-#define NILFS_FEATURE_COMPAT_RO_SUPP	0ULL
+#define NILFS_FEATURE_COMPAT_RO_SUPP	NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT
 #define NILFS_FEATURE_INCOMPAT_SUPP	0ULL
 
 /*
@@ -509,7 +511,7 @@ struct nilfs_checkpoint {
 	__le64 cp_create;
 	__le64 cp_nblk_inc;
 	__le64 cp_inodes_count;
-	__le64 cp_blocks_count;		/* Reserved (might be deleted) */
+	__le64 cp_blocks_count;
 
 	/* Do not change the byte offset of ifile inode.
 	   To keep the compatibility of the disk format,