Eric Lee / smarc-fsl-linux-kernel

27 Apr, 2018

1 commit

  • b4678df18   errseq: Always report a writeback error once ... Browse Code »

    The errseq_t infrastructure assumes that errors which occurred before
    the file descriptor was opened are of no interest to the application.
    This turns out to be a regression for some applications, notably Postgres.

    Before errseq_t, a writeback error would be reported exactly once (as
    long as the inode remained in memory), so Postgres could open a file,
    call fsync() and find out whether there had been a writeback error on
    that file from another process.

    This patch changes the errseq infrastructure to report errors to all
    file descriptors which are opened after the error occurred, but before
    it was reported to any file descriptor. This restores the user-visible
    behaviour.

    Cc: stable@vger.kernel.org
    Fixes: 5660e13d2fd6 ("fs: new infrastructure for writeback error handling and reporting")
    Signed-off-by: Matthew Wilcox
    Reviewed-by: Jeff Layton
    Signed-off-by: Jeff Layton

    Matthew Wilcox
     

02 Jan, 2018

1 commit

  • 14ebc28e0   errseq: Add to documentation tree ... Browse Code »

    - Move errseq.rst into core-api
    - Add errseq to the core-api index
    - Promote the header to a more prominent header type, otherwise we get three
    entries in the table of contents.
    - Reformat the table to look nicer and be a little more proportional in
    terms of horizontal width per bit (the SF bit is still disproportionately
    large, but there's no way to fix that).
    - Include errseq kernel-doc in the errseq.rst
    - Neaten some kernel-doc markup

    Signed-off-by: Matthew Wilcox
    Reviewed-by: Jeff Layton
    Reviewed-by: Randy Dunlap
    Signed-off-by: Jonathan Corbet

    Matthew Wilcox
     

02 Nov, 2017

1 commit

  • b24413180   License cleanup: add SPDX GPL-2.0 license identifier to files with no license ... Browse Code »

    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
     

27 Jul, 2017

1 commit

06 Jul, 2017

1 commit

  • 84cbadadc   lib: add errseq_t type and infrastructure for handling it ... Browse Code »

    An errseq_t is a way of recording errors in one place, and allowing any
    number of "subscribers" to tell whether an error has been set again
    since a previous time.

    It's implemented as an unsigned 32-bit value that is managed with atomic
    operations. The low order bits are designated to hold an error code
    (max size of MAX_ERRNO). The upper bits are used as a counter.

    The API works with consumers sampling an errseq_t value at a particular
    point in time. Later, that value can be used to tell whether new errors
    have been set since that time.

    Note that there is a 1 in 512k risk of collisions here if new errors
    are being recorded frequently, since we have so few bits to use as a
    counter. To mitigate this, one bit is used as a flag to tell whether the
    value has been sampled since a new value was recorded. That allows
    us to avoid bumping the counter if no one has sampled it since it
    was last bumped.

    Later patches will build on this infrastructure to change how writeback
    errors are tracked in the kernel.

    Signed-off-by: Jeff Layton
    Reviewed-by: NeilBrown
    Reviewed-by: Jan Kara

    Jeff Layton