Eric Lee / smarc-fsl-linux-kernel

17 Mar, 2016

1 commit

07 Dec, 2015

3 commits

01 Jul, 2015

1 commit

  • ede1bf0dc   fs: use seq_open_private() for proc_mounts ... Browse Code »

    A patchset to remove support for passing pre-allocated struct seq_file to
    seq_open(). Such feature is undocumented and prone to error.

    In particular, if seq_release() is used in release handler, it will
    kfree() a pointer which was not allocated by seq_open().

    So this patchset drops support for pre-allocated struct seq_file: it's
    only of use in proc_namespace.c and can be easily replaced by using
    seq_open_private()/seq_release_private().

    Additionally, it documents the use of file->private_data to hold pointer
    to struct seq_file by seq_open().

    This patch (of 3):

    Since patch described below, from v2.6.15-rc1, seq_open() could use a
    struct seq_file already allocated by the caller if the pointer to the
    structure is stored in file->private_data before calling the function.

    Commit 1abe77b0fc4b485927f1f798ae81a752677e1d05
    Author: Al Viro
    Date: Mon Nov 7 17:15:34 2005 -0500

    [PATCH] allow callers of seq_open do allocation themselves

    Allow caller of seq_open() to kmalloc() seq_file + whatever else they
    want and set ->private_data to it. seq_open() will then abstain from
    doing allocation itself.

    Such behavior is only used by mounts_open_common().

    In order to drop support for such uncommon feature, proc_mounts is
    converted to use seq_open_private(), which take care of allocating the
    proc_mounts structure, making it available through ->private in struct
    seq_file.

    Conversely, proc_mounts is converted to use seq_release_private(), in
    order to release the private structure allocated by seq_open_private().

    Then, ->private is used directly instead of proc_mounts() macro to access
    to the proc_mounts structure.

    Link: http://lkml.kernel.org/r/cover.1433193673.git.ydroneaud@opteya.com
    Signed-off-by: Yann Droneaud
    Cc: Al Viro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Yann Droneaud
     

05 Feb, 2015

1 commit

  • 0ae45f63d   vfs: add support for a lazytime mount option ... Browse Code »

    Add a new mount option which enables a new "lazytime" mode. This mode
    causes atime, mtime, and ctime updates to only be made to the
    in-memory version of the inode. The on-disk times will only get
    updated when (a) if the inode needs to be updated for some non-time
    related change, (b) if userspace calls fsync(), syncfs() or sync(), or
    (c) just before an undeleted inode is evicted from memory.

    This is OK according to POSIX because there are no guarantees after a
    crash unless userspace explicitly requests via a fsync(2) call.

    For workloads which feature a large number of random write to a
    preallocated file, the lazytime mount option significantly reduces
    writes to the inode table. The repeated 4k writes to a single block
    will result in undesirable stress on flash devices and SMR disk
    drives. Even on conventional HDD's, the repeated writes to the inode
    table block will trigger Adjacent Track Interference (ATI) remediation
    latencies, which very negatively impact long tail latencies --- which
    is a very big deal for web serving tiers (for example).

    Google-Bug-Id: 18297052

    Signed-off-by: Theodore Ts'o
    Signed-off-by: Al Viro

    Theodore Ts'o
     

17 Dec, 2014

2 commits

  • 9d4d65748   vfs: make mounts and mountstats honor root dir like mountinfo does ... Browse Code »

    As we already show mountpoints relative to the root directory, thanks
    to the change made back in 2000, change show_vfsmnt() and show_vfsstat()
    to skip out-of-root mountpoints the same way as show_mountinfo() does.

    Signed-off-by: Dmitry V. Levin
    Signed-off-by: Al Viro

    Dmitry V. Levin
     
  • 9ad4dc4f7   vfs: cleanup show_mountinfo ... Browse Code »

    Starting with commit v3.2-rc4-1-g02125a8, seq_path_root() no longer
    changes the value of its "struct path *root" argument.
    Starting with commit v3.2-rc7-104-g8c9379e, the "struct path *root"
    argument of seq_path_root() is const.
    As result, the temporary variable "root" in show_mountinfo() that
    holds a copy of struct path root is no longer needed.

    Signed-off-by: Dmitry V. Levin
    Signed-off-by: Al Viro

    Dmitry V. Levin
     

30 Jul, 2014

1 commit

  • 728dba3a3   namespaces: Use task_lock and not rcu to protect nsproxy ... Browse Code »

    The synchronous syncrhonize_rcu in switch_task_namespaces makes setns
    a sufficiently expensive system call that people have complained.

    Upon inspect nsproxy no longer needs rcu protection for remote reads.
    remote reads are rare. So optimize for same process reads and write
    by switching using rask_lock instead.

    This yields a simpler to understand lock, and a faster setns system call.

    In particular this fixes a performance regression observed
    by Rafael David Tinoco .

    This is effectively a revert of Pavel Emelyanov's commit
    cf7b708c8d1d7a27736771bcf4c457b332b0f818 Make access to task's nsproxy lighter
    from 2007. The race this originialy fixed no longer exists as
    do_notify_parent uses task_active_pid_ns(parent) instead of
    parent->nsproxy.

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

    Eric W. Biederman
     

02 Apr, 2014

1 commit

24 Jan, 2014

1 commit

25 Oct, 2013

1 commit

14 Jul, 2012

1 commit

30 May, 2012

1 commit

  • 962830df3   brlocks/lglocks: API cleanups ... Browse Code »

    lglocks and brlocks are currently generated with some complicated macros
    in lglock.h. But there's no reason to not just use common utility
    functions and put all the data into a common data structure.

    In preparation, this patch changes the API to look more like normal
    function calls with pointers, not magic macros.

    The patch is rather large because I move over all users in one go to keep
    it bisectable. This impacts the VFS somewhat in terms of lines changed.
    But no actual behaviour change.

    [akpm@linux-foundation.org: checkpatch fixes]
    Signed-off-by: Andi Kleen
    Cc: Al Viro
    Cc: Rusty Russell
    Signed-off-by: Andrew Morton
    Signed-off-by: Rusty Russell
    Signed-off-by: Al Viro

    Andi Kleen
     

07 Jan, 2012

4 commits

04 Jan, 2012

1 commit