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>

1 files changed, 4 insertions, 2 deletions

diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 3a65e5aa2d76..ae33ac2db62d 100644
--- a/include/linux/nilfs2_fs.h
+++ b/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,