On 12/21/20 10:49 PM, Naohiro Aota wrote:

Zoned device has its own hardware restrictions e.g. max_zone_append_size
when using REQ_OP_ZONE_APPEND. To follow the restrictions, use
bio_add_zone_append_page() instead of bio_add_page(). We need target device
to use bio_add_zone_append_page(), so this commit reads the chunk
information to memoize the target device to btrfs_io_bio(bio)->device.

Currently, zoned btrfs only supports SINGLE profile. In the feature,
btrfs_io_bio can hold extent_map and check the restrictions for all the
devices the bio will be mapped.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef