On Thu 14-09-17 11:50:47, Andreas Gruenbacher wrote:
> @@ -3422,9 +3422,38 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
> map.m_lblk = first_block;
> map.m_len = last_block - first_block + 1;
>
> - if (!(flags & IOMAP_WRITE)) {
> + if (flags & IOMAP_REPORT) {
> ret = ext4_map_blocks(NULL, inode, &map, 0);
> - } else {
> + if (ret < 0)
> + return ret;
> +
> + if (ret == 0) {
> + ext4_lblk_t end = map.m_lblk + map.m_len - 1;
> + struct extent_status es;
> +
> + ext4_es_find_delayed_extent_range(inode, map.m_lblk, end, &es);
> +
> + if (!es.es_len || es.es_lblk > end) {
> + /* entire range is a hole */
> + } else if (es.es_lblk > map.m_lblk) {
> + /* range starts with a hole */
> + map.m_len = es.es_lblk - map.m_lblk;
> + } else {
> + ext4_lblk_t offs = 0;
> +
> + if (es.es_lblk < map.m_lblk)
> + offs = map.m_lblk - es.es_lblk;
> + map.m_lblk = es.es_lblk + offs;
> + map.m_pblk = ext4_es_pblock(&es) + offs;
> + map.m_len = es.es_len - offs;
> + if (ext4_es_is_unwritten(&es))
> + map.m_flags |= EXT4_MAP_UNWRITTEN;
This is not possible. If there is unwritten extent at map->m_lblk, then
ext4_map_blocks() could not have possibly returned 0. So just delete this
condition and set map.m_pblk to 0 since delalloc extent has no physical
possition.
> + if (ext4_es_is_delayed(&es))
> + delalloc = true;
Also ext4_es_is_delayed(&es) is guaranteed to be true since you've looked
it up by ext4_es_find_delayed_extent_range(). So just set delalloc = true
unconditionally.
Otherwise the patch looks good so after fixing up these small issues feel
free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
