On 3/25/24 05:44, Damien Le Moal wrote:
Given that zone write plugging manages all writes to zones of a zoned block device and track the write pointer position of all zones, emulating zone append operations using regular writes can be implemented generically, without relying on the underlying device driver to implement such emulation. This is needed for devices that do not natively support the zone append command, e.g. SMR hard-disks. A device may request zone append emulation by setting its max_zone_append_sectors queue limit to 0. For such device, the function blk_zone_wplug_prepare_bio() changes zone append BIOs into non-mergeable regular write BIOs. Modified zone append BIOs are flagged with the new BIO flag BIO_EMULATES_ZONE_APPEND. This flag is checked on completion of the BIO in blk_zone_write_plug_bio_endio() to restore the original REQ_OP_ZONE_APPEND operation code of the BIO. The block layer internal inline helper function bio_is_zone_append() is added to test if a BIO is either a native zone append operation (REQ_OP_ZONE_APPEND operation code) or if it is flagged with BIO_EMULATES_ZONE_APPEND. Given that both native and emulated zone append BIO completion handling should be similar, The functions blk_update_request() and blk_zone_complete_request_bio() are modified to use bio_is_zone_append() to execute blk_zone_update_request_bio() for both native and emulated zone append operations. This commit contains contributions from Christoph Hellwig <hch@xxxxxx>. Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx> --- block/blk-mq.c | 2 +- block/blk-zoned.c | 69 +++++++++++++++++++++++++++++++-------- block/blk.h | 14 ++++++-- include/linux/blk_types.h | 1 + 4 files changed, 69 insertions(+), 17 deletions(-)
Reviewed-by: Hannes Reinecke <hare@xxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich
