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
     

20 Jun, 2017

2 commits

  • So I've noticed a number of instances where it was not obvious from the
    code whether ->task_list was for a wait-queue head or a wait-queue entry.

    Furthermore, there's a number of wait-queue users where the lists are
    not for 'tasks' but other entities (poll tables, etc.), in which case
    the 'task_list' name is actively confusing.

    To clear this all up, name the wait-queue head and entry list structure
    fields unambiguously:

    struct wait_queue_head::task_list => ::head
    struct wait_queue_entry::task_list => ::entry

    For example, this code:

    rqw->wait.task_list.next != &wait->task_list

    ... is was pretty unclear (to me) what it's doing, while now it's written this way:

    rqw->wait.head.next != &wait->entry

    ... which makes it pretty clear that we are iterating a list until we see the head.

    Other examples are:

    list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
    list_for_each_entry(wq, &fence->wait.task_list, task_list) {

    ... where it's unclear (to me) what we are iterating, and during review it's
    hard to tell whether it's trying to walk a wait-queue entry (which would be
    a bug), while now it's written as:

    list_for_each_entry_safe(pos, next, &x->head, entry) {
    list_for_each_entry(wq, &fence->wait.head, entry) {

    Cc: Linus Torvalds
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     
  • Rename:

    wait_queue_t => wait_queue_entry_t

    'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
    but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
    which had to carry the name.

    Start sorting this out by renaming it to 'wait_queue_entry_t'.

    This also allows the real structure name 'struct __wait_queue' to
    lose its double underscore and become 'struct wait_queue_entry',
    which is the more canonical nomenclature for such data types.

    Cc: Linus Torvalds
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

10 Apr, 2015

1 commit

  • This is needed to support lazily umounting locked mounts. Because the
    entire unmounted subtree needs to stay together until there are no
    users with references to any part of the subtree.

    To support this guarantee that the fs_pin m_list and s_list nodes
    are initialized by initializing them in init_fs_pin allowing
    for the possibility that pin_insert_group does not touch them.

    Further use hlist_del_init in pin_remove so that there is
    a hlist_unhashed test before the list we attempt to update
    the previous list item.

    Signed-off-by: "Eric W. Biederman"

    Eric W. Biederman
     

26 Jan, 2015

5 commits


08 Aug, 2014

2 commits

  • These externs belong in fs/internal.h. Rename (they are not acct-specific
    anymore) and move them over there.

    Signed-off-by: Al Viro

    Al Viro
     
  • Add a new field to fs_pin - kill(pin). That's what umount and r/o remount
    will be calling for all pins attached to vfsmount and superblock resp.
    Called after bumping the refcount, so it won't go away under us. Dropping
    the refcount is responsibility of the instance. All generic stuff moved to
    fs/fs_pin.c; the next step will rip all the knowledge of kernel/acct.c from
    fs/super.c and fs/namespace.c. After that - death to mnt_pin(); it was
    intended to be usable as generic mechanism for code that wants to attach
    objects to vfsmount, so that they would not make the sucker busy and
    would get killed on umount. Never got it right; it remained acct.c-specific
    all along. Now it's very close to being killable.

    Signed-off-by: Al Viro

    Al Viro