linux/drivers/lightnvm, branch v4.14

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

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: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

lightnvm: pblk: advance bio according to lba index

2017-07-28T14:06:00Z

When a lba either hits the cache or corresponds to an empty entry in the L2P table, we need to advance the bio according to the position in which the lba is located. Otherwise, we will copy data in the wrong page, thus causing data corruption for the application. In case of a cache hit, we assumed that bio->bi_iter.bi_idx would contain the correct index, but this is no necessarily true. Instead, use the local bio advance counter and iterator. This guarantees that lbas hitting the cache are copied into the right bv_page. In case of an empty L2P entry, we omitted to advance the bio. In the cases when the same I/O also contains a cache hit, data corresponding to this lba will be copied to the wrong bv_page. Fix this by advancing the bio as we do in the case of a cache hit. Fixes: a4bd217b4326 lightnvm: physical block device (pblk) target Signed-off-by: Javier González Signed-off-by: Jens Axboe

lightnvm: pblk: remove unnecessary checks

2017-07-07T19:17:36Z

Remove unnecessary checks when freeing dma memory in the completion path. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: control I/O flow also on tear down

2017-07-07T19:17:34Z

When removing a pblk instance, control the write I/O flow to the controller as we do in the fast path. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: set line bitmap check under debug

2017-06-30T17:08:18Z

Do bitmap checks only when debug mode is enable. The line bitmap used for mapping to physical addresses is fairly large (~512KB) and it is expensive to do this checks on the fast path. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: verify that cache read is still valid

2017-06-30T17:08:18Z

When a read is directed to the cache, we risk that the lba has been updated during the time we made the L2P table lookup and the time we are actually reading form the cache. We intentionally not hold the L2P lock not to block other threads. While strict ordering is not a guarantee at this level (unless REQ_FLUSH has been previously issued), we have experience that some databases that have recently implemented direct I/O support, issue metadata reads very close to the writes, without issuing a fsync in the middle. An easy way to support them while they is to make an extra effort and check the L2P map right before reading the cache. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: add initialization check

2017-06-30T17:08:18Z

Add a sanity check to the pblk initialization sequence in order to ensure that enough LUNs have been allocated to store the line metadata. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: remove target using async. I/Os

2017-06-30T17:08:18Z

When removing a pblk instance, pad the current line using asynchronous I/O. This reduces the removal time from ~1 minute in the worst case to a couple of seconds. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: use vmalloc for GC data buffer

2017-06-30T17:08:18Z

For now, we allocate a per I/O buffer for GC data. Since the potential size of the buffer is 256KB and GC is not in the fast path, do this allocation with vmalloc. This puts lets pressure on the memory allocator at no performance cost. Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe

lightnvm: pblk: use right metadata buffer for recovery

2017-06-30T17:08:18Z

Fix bad metadata buffer assignations introduced when refactoring the medatada write path. Fixes: dd2a43437337 lightnvm: pblk: sched. metadata on write thread Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe