02 Nov, 2017

1 commit

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

    Greg Kroah-Hartman
     

31 Mar, 2015

1 commit

  • Linux 3.19 commit 69c953c ("lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n")
    caused blk_stack_limits() to not properly stack queue_limits for stacked
    devices (e.g. DM).

    Fix this regression by establishing lcm_not_zero() and switching
    blk_stack_limits() over to using it.

    DM uses blk_set_stacking_limits() to establish the initial top-level
    queue_limits that are then built up based on underlying devices' limits
    using blk_stack_limits(). In the case of optimal_io_size (io_opt)
    blk_set_stacking_limits() establishes a default value of 0. With commit
    69c953c, lcm(0, n) is no longer n, which compromises proper stacking of
    the underlying devices' io_opt.

    Test:
    $ modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536
    $ cat /sys/block/sde/queue/optimal_io_size
    786432
    $ dmsetup create node --table "0 100 linear /dev/sde 0"

    Before this fix:
    $ cat /sys/block/dm-5/queue/optimal_io_size
    0

    After this fix:
    $ cat /sys/block/dm-5/queue/optimal_io_size
    786432

    Signed-off-by: Mike Snitzer
    Cc: stable@vger.kernel.org # 3.19+
    Acked-by: Martin K. Petersen
    Signed-off-by: Jens Axboe

    Mike Snitzer
     

15 Mar, 2010

1 commit

  • lcm() was defined to take integer-sized arguments. The supplied
    arguments are multiplied, however, causing us to overflow given
    sufficiently large input. That in turn led to incorrect optimal I/O
    size reporting in some cases (RAID over RAID).

    Switch lcm() over to unsigned long similar to gcd() and move the
    function from blk-settings.c to lib.

    Signed-off-by: Martin K. Petersen
    Signed-off-by: Jens Axboe

    Martin K. Petersen