nilfs2: zero fill unused portion of super root block

The super root block is newly-allocated each time it is written back
to disk, so unused portion of the block should be cleared.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 2cc8c08..699170e 100644 (file)
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -596,6 +596,16 @@ void nilfs_write_inode_common(struct inode *inode,
        raw_inode->i_flags = cpu_to_le32(ii->i_flags);
        raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 
+       if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
+               struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
+
+               /* zero-fill unused portion in the case of super root block */
+               raw_inode->i_xattr = 0;
+               raw_inode->i_pad = 0;
+               memset((void *)raw_inode + sizeof(*raw_inode), 0,
+                      nilfs->ns_inode_size - sizeof(*raw_inode));
+       }
+
        if (has_bmap)
                nilfs_bmap_write(ii->i_bmap, raw_inode);
        else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 8006d0c..8a2b428 100644 (file)
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -889,12 +889,14 @@ static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
 {
        struct buffer_head *bh_sr;
        struct nilfs_super_root *raw_sr;
-       unsigned isz = nilfs->ns_inode_size;
+       unsigned isz, srsz;
 
        bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
        raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
+       isz = nilfs->ns_inode_size;
+       srsz = NILFS_SR_BYTES(isz);
 
-       raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES(isz));
+       raw_sr->sr_bytes = cpu_to_le16(srsz);
        raw_sr->sr_nongc_ctime
                = cpu_to_le64(nilfs_doing_gc() ?
                              nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
@@ -906,6 +908,7 @@ static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
                                 NILFS_SR_CPFILE_OFFSET(isz), 1);
        nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
                                 NILFS_SR_SUFILE_OFFSET(isz), 1);
+       memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
 }
 
 static void nilfs_redirty_inodes(struct list_head *head)