1. 05 Jan, 2018 1 commit
  2. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  3. 16 Apr, 2017 1 commit
    • Javier González's avatar
      lightnvm: physical block device (pblk) target · a4bd217b
      Javier González authored
      This patch introduces pblk, a host-side translation layer for
      Open-Channel SSDs to expose them like block devices. The translation
      layer allows data placement decisions, and I/O scheduling to be
      managed by the host, enabling users to optimize the SSD for their
      specific workloads.
      
      An open-channel SSD has a set of LUNs (parallel units) and a
      collection of blocks. Each block can be read in any order, but
      writes must be sequential. Writes may also fail, and if a block
      requires it, must also be reset before new writes can be
      applied.
      
      To manage the constraints, pblk maintains a logical to
      physical address (L2P) table,  write cache, garbage
      collection logic, recovery scheme, and logic to rate-limit
      user I/Os versus garbage collection I/Os.
      
      The L2P table is fully-associative and manages sectors at a
      4KB granularity. Pblk stores the L2P table in two places, in
      the out-of-band area of the media and on the last page of a
      line. In the cause of a power failure, pblk will perform a
      scan to recover the L2P table.
      
      The user data is organized into lines. A line is data
      striped across blocks and LUNs. The lines enable the host to
      reduce the amount of metadata to maintain besides the user
      data and makes it easier to implement RAID or erasure coding
      in the future.
      
      pblk implements multi-tenant support and can be instantiated
      multiple times on the same drive. Each instance owns a
      portion of the SSD - both regarding I/O bandwidth and
      capacity - providing I/O isolation for each case.
      
      Finally, pblk also exposes a sysfs interface that allows
      user-space to peek into the internals of pblk. The interface
      is available at /dev/block/*/pblk/ where * is the block
      device name exposed.
      
      This work also contains contributions from:
        Matias Bjørling <matias@cnexlabs.com>
        Simon A. F. Lund <slund@cnexlabs.com>
        Young Tack Jin <youngtack.jin@gmail.com>
        Huaicheng Li <huaicheng@cs.uchicago.edu>
      Signed-off-by: default avatarJavier González <javier@cnexlabs.com>
      Signed-off-by: default avatarMatias Bjørling <matias@cnexlabs.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      a4bd217b
  4. 31 Jan, 2017 1 commit
    • Matias Bjørling's avatar
      lightnvm: merge gennvm with core · ade69e24
      Matias Bjørling authored
      For the first iteration of Open-Channel SSDs, it was anticipated that
      there could be various media managers on top of an open-channel SSD,
      such to allow vendors to plug in their own host-side FTLs, without the
      media manager in between.
      
      Now that an Open-Channel SSD is exposed as a traditional block device,
      there is no longer a need for this. Therefore lets merge the gennvm code
      with core and simplify the stack.
      Signed-off-by: default avatarMatias Bjørling <matias@cnexlabs.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      ade69e24
  5. 29 Nov, 2016 1 commit
  6. 21 Sep, 2016 1 commit
    • Simon A. F. Lund's avatar
      lightnvm: expose device geometry through sysfs · 40267efd
      Simon A. F. Lund authored
      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: default avatarSimon A. F. Lund <slund@cnexlabs.com>
      Signed-off-by: default avatarMatias Bjørling <m@bjorling.me>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      40267efd
  7. 12 Jan, 2016 1 commit
    • Matias Bjørling's avatar
      lightnvm: core on-disk initialization · e3eb3799
      Matias Bjørling authored
      An Open-Channel SSD shall be initialized before use. To initialize, we
      define an on-disk format, that keeps a small set of metadata to bring up
      the media manager on top of the device.
      
      The initial step is introduced to allow a user to format the disks for a
      given media manager. During format, a system block is stored on one to
      three separate luns on the device. Each lun has the system block
      duplicated. During initialization, the system block can be retrieved and
      the appropriate media manager can initialized.
      
      The on-disk format currently covers (struct nvm_system_block):
      
       - Magic value "NVMS".
       - Monotonic increasing sequence number.
       - The physical block erase count.
       - Version of the system block format.
       - Media manager type.
       - Media manager superblock physical address.
      
      The interface provides three functions to manage the system block:
      
       int nvm_init_sysblock(struct nvm_dev *, struct nvm_sb_info *)
       int nvm_get_sysblock(struct nvm *dev, struct nvm_sb_info *)
       int nvm_update_sysblock(struct nvm *dev, struct nvm_sb_info *)
      
      Each implement a part of the logic to manage the system block. The
      initialization creates the first system blocks and mark them on the
      device. Get retrieves the latest system block by scanning all pages in
      the associated system blocks. The update sysblock writes new metadata
      and allocates new block if necessary.
      Signed-off-by: default avatarMatias Bjørling <m@bjorling.me>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      e3eb3799
  8. 29 Oct, 2015 3 commits
    • Matias Bjørling's avatar
      rrpc: Round-robin sector target with cost-based gc · ae1519ec
      Matias Bjørling authored
      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: default avatarMatias Bjørling <m@bjorling.me>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      ae1519ec
    • Matias Bjørling's avatar
      gennvm: Generic NVM manager · 48add0f5
      Matias Bjørling authored
      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: default avatarMatias Bjørling <m@bjorling.me>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      48add0f5
    • Matias Bjørling's avatar
      lightnvm: Support for Open-Channel SSDs · cd9e9808
      Matias Bjørling authored
      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: default avatarMatias Bjørling <m@bjorling.me>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      cd9e9808