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lightnvm: Support for Open-Channel SSDs Open-channel SSDs are devices that share responsibilities with the host in order to implement and maintain features that typical SSDs keep strictly in firmware. These include (i) the Flash Translation Layer (FTL), (ii) bad block management, and (iii) hardware units such as the flash controller, the interface controller, and large amounts of flash chips. In this way, Open-channels SSDs exposes direct access to their physical flash storage, while keeping a subset of the internal features of SSDs. LightNVM is a specification that gives support to Open-channel SSDs LightNVM allows the host to manage data placement, garbage collection, and parallelism. Device specific responsibilities such as bad block management, FTL extensions to support atomic IOs, or metadata persistence are still handled by the device. The implementation of LightNVM consists of two parts: core and (multiple) targets. The core implements functionality shared across targets. This is initialization, teardown and statistics. The targets implement the interface that exposes physical flash to user-space applications. Examples of such targets include key-value store, object-store, as well as traditional block devices, which can be application-specific. Contributions in this patch from: Javier Gonzalez <jg@lightnvm.io> Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Jesper Madsen <jmad@itu.dk> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com> 2015-10-28 19:54:55 +01:00



lightnvm: expose device geometry through sysfs For a host to access an Open-Channel SSD, it has to know its geometry, so that it writes and reads at the appropriate device bounds. Currently, the geometry information is kept within the kernel, and not exported to user-space for consumption. This patch exposes the configuration through sysfs and enables user-space libraries, such as liblightnvm, to use the sysfs implementation to get the geometry of an Open-Channel SSD. The sysfs entries are stored within the device hierarchy, and can be found using the "lightnvm" device type. An example configuration looks like this: /sys/class/nvme/ └── nvme0n1 ├── capabilities: 3 ├── device_mode: 1 ├── erase_max: 1000000 ├── erase_typ: 1000000 ├── flash_media_type: 0 ├── media_capabilities: 0x00000001 ├── media_type: 0 ├── multiplane: 0x00010101 ├── num_blocks: 1022 ├── num_channels: 1 ├── num_luns: 4 ├── num_pages: 64 ├── num_planes: 1 ├── page_size: 4096 ├── prog_max: 100000 ├── prog_typ: 100000 ├── read_max: 10000 ├── read_typ: 10000 ├── sector_oob_size: 0 ├── sector_size: 4096 ├── media_manager: gennvm ├── ppa_format: 0x380830082808001010102008 ├── vendor_opcode: 0 ├── max_phys_secs: 64 └── version: 1 Signed-off-by: Simon A. F. Lund <slund@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com> 2016-09-16 14:25:08 +02:00
gennvm: Generic NVM manager The implementation for Open-Channel SSDs is divided into media management and targets. This patch implements a generic media manager for open-channel SSDs. After a media manager has been initialized, single or multiple targets can be instantiated with the media managed as the backend. Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com> 2015-10-28 19:54:56 +01:00
rrpc: Round-robin sector target with cost-based gc This target allows an Open-Channel SSD to be exposed asas a block device. It implements a round-robin approach for sector allocation, together with a greedy cost-based garbage collector. Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com> 2015-10-28 19:54:57 +01:00