[Ocfs2-tools-devel] [PATCH 05/10] libocfs2: read/write now know inline data.

[Joel Becker]

On Fri, Jul 11, 2008 at 02:20:58PM +0800, Tao Ma wrote:
> +static errcode_t ocfs2_convert_inline_data_to_extents(ocfs2_cached_inode *ci)
> +{
> +	errcode_t ret;
> +	uint32_t bytes;
> +	char *inline_data = NULL;
> +	struct ocfs2_dinode *di = ci->ci_inode;
> +	ocfs2_filesys *fs = ci->ci_fs;
> +
> +	if (di->i_size) {
> +		ret = ocfs2_malloc_block(fs->fs_io, &inline_data);
> +		if (ret)
> +			goto out;
> +
> +		ret = ocfs2_inline_data_read(di, inline_data,
> +					     fs->fs_blocksize,
> +					     0, &bytes);
> +		if (ret)
> +			goto out;
> +
> +		ocfs2_dinode_new_extent_list(fs, di);
> +		di->i_dyn_features &= ~OCFS2_INLINE_DATA_FL;
> +		ret = ocfs2_write_cached_inode(fs, ci);
> +		if (ret)
> +			goto out;
> +
> +		ret = ocfs2_file_block_write(ci, inline_data,
> +					     fs->fs_blocksize,
> +					     0, &bytes);
> +		if (ret)
> +			goto out;
> +	}
> +
> +out:
> +	if (inline_data)
> +		ocfs2_free(&inline_data);
> +	return ret;
> +}

	Actually, Tao, can we do this differently?  While it's pretty
creative to use file_block_write to add the extents, it has the same
problem as the directory code.  It wipes the data, writes out the inode,
then tries to add the extents - a crash is a problem, and so is ENOSPC
in this case.
	Can you instead write ocfs2_cached_inode_insert_extent() to make
the extent insertion safe?  Then write a public function
ocfs2_inline_data_to_extents() that allocates the extent, writes the
data to the extent, and uses ocfs2_cached_inode_insert_extent() to
insert it?  This makes it safe (ocfs2_write_cached_inode() is the last
step).  At the bottom of ocfs2_inline_data_to_extents() can check
S_ISDIR() and fixup the dirent.  Plus, we can use that for tunefs
--fsfeatures noinline.

Joel

-- 

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Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127