user/sven/linux.git/include/target, branch v5.14.9

scsi: target: core: Add configurable IEEE Company ID attribute

2021-05-15T18:14:28Z

Implement an attribute which provides a way to set a company specific WWN in configfs via: target/core/$backstore/$name/wwn/company_id The Open Fabrics Alliance ID 001405h remains the default. Link: https://lore.kernel.org/r/20210420185920.42431-3-s.samoylenko@yadro.com Signed-off-by: Sergey Samoylenko Signed-off-by: Roman Bolshakov Signed-off-by: Martin K. Petersen

scsi: target: core: Make completion affinity configurable

2021-03-04T22:37:03Z

It may not always be best to complete the IO on same CPU as it was submitted on. This commit allows userspace to configure it. This has been useful for vhost-scsi where we have a single thread for submissions and completions. If we force the completion on the submission CPU we may be adding conflicts with what the user has setup in the lower levels with settings like the block layer rq_affinity or the driver's IRQ or softirq (the network's rps_cpus value) settings. We may also want to set it up where the vhost thread runs on CPU N and does its submissions/completions there, and then have LIO do its completion booking on CPU M, but can't configure the lower levels due to issues like using dm-multipath with lots of paths (the path selector can throw commands all over the system because it's only taking into account latency/throughput at its level). The new setting is in: /sys/kernel/config/target/$fabric/$target/param/cmd_completion_affinity Writing: -1 -> Gives the current default behavior of completing on the submission CPU. -2 -> Completes the cmd on the CPU the lower layers sent it to us from. > 0 -> Completes on the CPU userspace has specified. Link: https://lore.kernel.org/r/20210227170006.5077-26-michael.christie@oracle.com Reviewed-by: Himanshu Madhani Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: Fix backend plugging

2021-03-04T22:37:02Z

target_core_iblock is plugging and unplugging on every command and this is causing perf issues for drivers that prefer batched cmds. With recent patches we can now take multiple cmds from a fabric driver queue and then pass them down the backend drivers in a batch. This patch adds this support by adding 2 callouts to the backend for plugging and unplugging the device. Subsequent commits will add support for iblock and tcmu device plugging. Link: https://lore.kernel.org/r/20210227170006.5077-22-michael.christie@oracle.com Reviewed-by: Bodo Stroesser Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: Cleanup cmd flag bits

2021-03-04T22:37:02Z

We have a couple holes in the cmd flags definitions. This cleans up the definitions to fix that and make it easier to read. Link: https://lore.kernel.org/r/20210227170006.5077-21-michael.christie@oracle.com Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Reviewed-by: Himanshu Madhani Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: Add workqueue based cmd submission

2021-03-04T22:37:02Z

loop and vhost/scsi do their target cmd submission from driver workqueues. This allows them to avoid an issue where the backend may block waiting for resources like tags/requests, mem/locks, etc and that ends up blocking their entire submission path and for the case of vhost-scsi both the submission and completion path. This patch adds a helper drivers can use to submit from a LIO workqueue. This code will then be extended in the next patches to fix the plugging of backend devices. We are only converting vhost/loop initially, but the workqueue based submission will work for other drivers and have similar benefits where the main target loops will not end up blocking one some backend resource. Link: https://lore.kernel.org/r/20210227170006.5077-17-michael.christie@oracle.com Tested-by: Laurence Oberman Reviewed-by: Bodo Stroesser Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: Add gfp_t arg to target_cmd_init_cdb()

2021-03-04T22:37:02Z

tcm_loop could be used like a normal block device, so we can't use GFP_KERNEL and should use GFP_NOIO. This adds a gfp_t arg to target_cmd_init_cdb() and converts the users. For every driver but loop GFP_KERNEL is kept. This will also be useful in subsequent patches where loop needs to do target_submit_prep() from interrupt context to get a ref to the se_device, and so it will need to use GFP_ATOMIC. Link: https://lore.kernel.org/r/20210227170006.5077-16-michael.christie@oracle.com Tested-by: Laurence Oberman Reviewed-by: Christoph Hellwig Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: Remove target_submit_cmd_map_sgls()

2021-03-04T22:37:01Z

Convert target_submit_cmd() to do its own calls and then remove target_submit_cmd_map_sgls() since no one uses it. Link: https://lore.kernel.org/r/20210227170006.5077-15-michael.christie@oracle.com Tested-by: Laurence Oberman Reviewed-by: Bodo Stroesser Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: Break up target_submit_cmd_map_sgls()

2021-03-04T22:37:00Z

This breaks up target_submit_cmd_map_sgls() into 3 helpers: - target_init_cmd(): Do the basic general setup and get a refcount to the session to make sure the caller can execute the cmd. - target_submit_prep(): Do the mapping, cdb processing and get a ref to the LUN. - target_submit(): Pass the cmd to LIO core for execution. The above functions must be used by drivers that either: 1. Rely on LIO for session shutdown synchronization by calling target_stop_session(). 2. Need to map sgls. When the next patches are applied then simple drivers that do not need the extra functionality above can use target_submit_cmd() and not worry about failures being returned and how to handle them, since many drivers were getting this wrong and would have hit refcount bugs. Also, by breaking target_submit_cmd_map_sgls() up into these 3 helper functions, we can allow the later patches to do the init/prep from interrupt context and then do the submission from a workqueue. Link: https://lore.kernel.org/r/20210227170006.5077-5-michael.christie@oracle.com Cc: Bart Van Assche Cc: Juergen Gross Cc: Hannes Reinecke Cc: Nilesh Javali Cc: Michael Cyr Cc: Chris Boot Cc: Felipe Balbi Cc: "Michael S. Tsirkin" Cc: Stefan Hajnoczi Tested-by: Laurence Oberman Reviewed-by: Christoph Hellwig Reviewed-by: Himanshu Madhani Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: Rename transport_init_se_cmd()

2021-03-04T22:37:00Z

Rename transport_init_se_cmd() to __target_init_cmd() to reflect that it is more of an internal function that drivers should normally not use and because we are going to add a new init function in the next patches. Link: https://lore.kernel.org/r/20210227170006.5077-4-michael.christie@oracle.com Reviewed-by: Christoph Hellwig Reviewed-by: Himanshu Madhani Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: Add cmd length set before cmd complete

2021-02-23T03:21:29Z

TCM doesn't properly handle underflow case for service actions. One way to prevent it is to always complete command with target_complete_cmd_with_length(), however it requires access to data_sg, which is not always available. This change introduces target_set_cmd_data_length() function which allows to set command data length before completing it. Link: https://lore.kernel.org/r/20210209072202.41154-2-a.miloserdov@yadro.com Reviewed-by: Roman Bolshakov Reviewed-by: Bodo Stroesser Signed-off-by: Aleksandr Miloserdov Signed-off-by: Martin K. Petersen