[Ocfs2-tools-devel] [PATCH 18/22] tunefs rework: Add feature_sparse_files.c

[Tao Ma]

Joel Becker wrote:
> Enable and disable the sparse file feature.
> 
> This is the 'sparse' key to the tunefs option '--fs-features'.
> 
> Signed-off-by: Joel Becker <joel.becker at oracle.com>
> ---

> +static errcode_t get_total_free_clusters(ocfs2_filesys *fs,
> +					 uint32_t *clusters)
This function and "empty_clusters" shows up in patch 17. So could you 
please abstract them out to be non-static?
> +{
> +	errcode_t ret;
> +	uint64_t blkno;
> +	char *buf = NULL;
> +	struct ocfs2_dinode *di = NULL;
> +
> +	ret = ocfs2_malloc_block(fs->fs_io, &buf);
> +	if (ret)
> +		goto bail;
> +
> +	ret = ocfs2_lookup_system_inode(fs, GLOBAL_BITMAP_SYSTEM_INODE,
> +					0, &blkno);
> +	if (ret)
> +		goto bail;
> +
> +	ret = ocfs2_read_inode(fs, blkno, buf);
> +	if (ret)
> +		goto bail;
> +
> +	di = (struct ocfs2_dinode *)buf;
> +	if (clusters)
> +		*clusters = di->id1.bitmap1.i_total - di->id1.bitmap1.i_used;
> +bail:
> +	if (buf)
> +		ocfs2_free(&buf);
> +	return ret;
> +}
> +
> +static int disable_sparse_files(ocfs2_filesys *fs, int flags)
> +{
> +	errcode_t ret = 0;
> +	struct ocfs2_super_block *super = OCFS2_RAW_SB(fs->fs_super);
> +	struct fill_hole_context ctxt;
> +
> +	if (!ocfs2_sparse_alloc(super)) {
> +		verbosef(VL_APP,
> +			 "Sparse file feature is not enabled; "
> +			 "nothing to disable\n");
> +		goto out;
> +	}
> +
> +	if (ocfs2_writes_unwritten_extents(super)) {
> +		errorf("Unwritten extents are enabled on device \"%s\"; "
> +		       "sparse files cannot be disabled\n",
> +		       fs->fs_devname);
> +		ret = TUNEFS_ET_UNWRITTEN_PRESENT;
> +		goto out;
> +	}
I remembered that if the user want to remove "sparse", unwritten is 
removed automatically by you now, right? So if we hit here, we may meet 
with a bug in tunefs. So should we say something loudly other than this?

Regards,
Tao