BMC/Intel-BMC/linux.git/drivers/nvme/target/loop.c, branch dev-4.10

block: improve handling of the magic discard payload

2016-12-09T15:30:51+00:00

Instead of allocating a single unused biovec for discard requests, send them down without any payload. Instead we allow the driver to add a "special" payload using a biovec embedded into struct request (unioned over other fields never used while in the driver), and overloading the number of segments for this case. This has a couple of advantages: - we don't have to allocate the bio_vec - the amount of special casing for discard requests in the block layer is significantly reduced - using this same scheme for other request types is trivial, which will be important for implementing the new WRITE_ZEROES op on devices where it actually requires a payload (e.g. SCSI) - we can get rid of playing games with the request length, as we'll never touch it and completions will work just fine - it will allow us to support ranged discard operations in the future by merging non-contiguous discard bios into a single request - last but not least it removes a lot of code This patch is the common base for my WIP series for ranges discards and to remove discard_zeroes_data in favor of always using REQ_OP_WRITE_ZEROES, so it would be good to get it in quickly. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

nvme-fabrics: set sqe.command_id in core not transports

2016-12-06T08:17:03+00:00

Currently, core.c sets command_id only on rd/wr commands, leaving it to the transport to set it again to ensure the request had a command id. Move location of set in core so applies to all commands. Remove transport sets. Signed-off-by: James Smart Reviewed-by: Jay Freyensee Signed-off-by: Sagi Grimberg

nvme: untangle 0 and BLK_MQ_RQ_QUEUE_OK

2016-11-15T19:50:11+00:00

Let's not depend on any of the BLK_MQ_RQ_QUEUE_* constants having specific values. No functional change. Signed-off-by: Omar Sandoval Reviewed-by: Keith Busch Signed-off-by: Jens Axboe

nvme: don't pass the full CQE to nvme_complete_async_event

2016-11-10T17:06:26+00:00

We only need the status and result fields, and passing them explicitly makes life a lot easier for the Fibre Channel transport which doesn't have a full CQE for the fast path case. Signed-off-by: Christoph Hellwig Reviewed-by: Keith Busch Signed-off-by: Jens Axboe

nvme: introduce struct nvme_request

2016-11-10T17:06:24+00:00

This adds a shared per-request structure for all NVMe I/O. This structure is embedded as the first member in all NVMe transport drivers request private data and allows to implement common functionality between the drivers. The first use is to replace the current abuse of the SCSI command passthrough fields in struct request for the NVMe command passthrough, but it will grow a field more fields to allow implementing things like common abort handlers in the future. The passthrough commands are handled by having a pointer to the SQE (struct nvme_command) in struct nvme_request, and the union of the possible result fields, which had to be turned from an anonymous into a named union for that purpose. This avoids having to pass a reference to a full CQE around and thus makes checking the result a lot more lightweight. Signed-off-by: Christoph Hellwig Reviewed-by: Keith Busch Signed-off-by: Jens Axboe

blk-mq: remove ->map_queue

2016-09-15T14:42:03+00:00

All drivers use the default, so provide an inline version of it. If we ever need other queue mapping we can add an optional method back, although supporting will also require major changes to the queue setup code. This provides better code generation, and better debugability as well. Signed-off-by: Christoph Hellwig Reviewed-by: Keith Busch Signed-off-by: Jens Axboe

nvme-loop: set sqsize to 0-based value, per spec

2016-08-18T06:58:06+00:00

Signed-off-by: Jay Freyensee Signed-off-by: Sagi Grimberg

nvme-loop: Remove duplicate call to nvme_remove_namespaces

2016-08-03T13:25:19+00:00

nvme_uninit_ctrl already does that for us. Note that we reordered nvme_loop_shutdown_ctrl with nvme_uninit_ctrl but its safe because we want controller uninit to happen before we shutdown the transport resources. Signed-off-by: Sagi Grimberg Reviewed-by: Christoph Hellwig

nvme-loop: add a NVMe loopback host driver

2016-07-05T17:30:36+00:00

This patch implements adds nvme-loop which allows to access local devices exported as NVMe over Fabrics namespaces. This module can be useful for easy evaluation, testing and also feature experimentation. To createa nvme-loop device you need to configure the NVMe target to export a loop port (see the nvmetcli documentaton for that) and then connect to it using nvme connect-all -t loop which requires the very latest nvme-cli version with Fabrics support. Signed-off-by: Jay Freyensee Signed-off-by: Ming Lin Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig Reviewed-by: Steve Wise Signed-off-by: Jens Axboe