Currently SCSI low-level drivers are required to manage tags for commands which do not come via the block layer - libata internal commands would be an example of one of these. We want to make blk-mq manage these tags also. There was some work to provide "reserved commands" support in such series as https://lore.kernel.org/linux-scsi/20211125151048.103910-1-hare@xxxxxxx/ This was based on allocating a request for the lifetime of the "internal" command. This series tries to solve that problem by not just allocating the request but also sending it as a request through the block layer. Reasons to do this: - Normal flow of a request and also commonality for regular scsi command lifetime - We don't leave request and scsi_cmnd fields dangling as when we just allocate and free the request for the lifetime of the "internal" command - For poll mode support we can only poll in block layer, so could not send internal commands on poll mode queues if we did not do this, which is a problem - Can get rid of duplicated code like libsas internal command timeout handling Based on v5.19-rc1 Please consider as an PoC for now. I have broken builds, bisectablility, and functionality for a lot of libsas drivers, like pm8001. Indeed, 10/18 onwards need a lot of work... Testing: QEMU with AHCI with disk and cdrom attached and hisi_sas v2 both boot. v1 was sent here: https://lore.kernel.org/linux-scsi/1647945585-197349-1-git-send-email-john.garry@xxxxxxxxxx/ Hannes Reinecke (1): scsi: core: Implement reserved command handling John Garry (17): blk-mq: Add a flag for reserved requests scsi: core: Resurrect scsi_{get,free}_host_dev() scsi: core: Add support to send reserved commands scsi: core: Allocate SCSI host sdev when required libata-scsi: Add ata_scsi_queue_internal() libata-scsi: Add ata_internal_queuecommand() libata: Queue ATA internal commands as requests scsi: ipr: Support reserved commands libata/scsi: libsas: Add sas_queuecommand_internal() scsi: libsas: Don't attempt to find scsi host rphy in slave alloc scsi: libsas drivers: Prepare for reserved commands scsi: libsas: Allocate SCSI commands for tasks scsi: libsas: Queue SMP commands as requests scsi: libsas: Queue TMF commands as requests scsi: core: Add scsi_alloc_request_hwq() scsi: libsas: Queue internal abort commands as requests scsi: libsas drivers: Remove private tag management block/blk-mq.c | 6 + drivers/ata/libata-core.c | 145 +++++++++++++++---------- drivers/ata/libata-sata.c | 5 +- drivers/ata/libata-scsi.c | 61 ++++++++++- drivers/ata/libata.h | 4 - drivers/scsi/hisi_sas/hisi_sas_main.c | 93 ++++------------ drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 6 +- drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 3 +- drivers/scsi/hosts.c | 14 +++ drivers/scsi/ipr.c | 17 ++- drivers/scsi/libsas/sas_ata.c | 22 ++-- drivers/scsi/libsas/sas_expander.c | 24 ++-- drivers/scsi/libsas/sas_init.c | 74 ++++++++----- drivers/scsi/libsas/sas_internal.h | 6 + drivers/scsi/libsas/sas_scsi_host.c | 121 +++++++++++++++------ drivers/scsi/scsi_lib.c | 50 ++++++++- drivers/scsi/scsi_scan.c | 57 ++++++++++ include/linux/blk-mq.h | 6 + include/linux/libata.h | 13 ++- include/scsi/libsas.h | 57 +++++++++- include/scsi/scsi_cmnd.h | 8 ++ include/scsi/scsi_host.h | 34 +++++- 22 files changed, 597 insertions(+), 229 deletions(-) -- 2.26.2
