13 Jan, 2012

1 commit


23 Oct, 2010

1 commit

  • * 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
    vfs: make no_llseek the default
    vfs: don't use BKL in default_llseek
    llseek: automatically add .llseek fop
    libfs: use generic_file_llseek for simple_attr
    mac80211: disallow seeks in minstrel debug code
    lirc: make chardev nonseekable
    viotape: use noop_llseek
    raw: use explicit llseek file operations
    ibmasmfs: use generic_file_llseek
    spufs: use llseek in all file operations
    arm/omap: use generic_file_llseek in iommu_debug
    lkdtm: use generic_file_llseek in debugfs
    net/wireless: use generic_file_llseek in debugfs
    drm: use noop_llseek

    Linus Torvalds
     

15 Oct, 2010

1 commit

  • All file_operations should get a .llseek operation so we can make
    nonseekable_open the default for future file operations without a
    .llseek pointer.

    The three cases that we can automatically detect are no_llseek, seq_lseek
    and default_llseek. For cases where we can we can automatically prove that
    the file offset is always ignored, we use noop_llseek, which maintains
    the current behavior of not returning an error from a seek.

    New drivers should normally not use noop_llseek but instead use no_llseek
    and call nonseekable_open at open time. Existing drivers can be converted
    to do the same when the maintainer knows for certain that no user code
    relies on calling seek on the device file.

    The generated code is often incorrectly indented and right now contains
    comments that clarify for each added line why a specific variant was
    chosen. In the version that gets submitted upstream, the comments will
    be gone and I will manually fix the indentation, because there does not
    seem to be a way to do that using coccinelle.

    Some amount of new code is currently sitting in linux-next that should get
    the same modifications, which I will do at the end of the merge window.

    Many thanks to Julia Lawall for helping me learn to write a semantic
    patch that does all this.

    ===== begin semantic patch =====
    // This adds an llseek= method to all file operations,
    // as a preparation for making no_llseek the default.
    //
    // The rules are
    // - use no_llseek explicitly if we do nonseekable_open
    // - use seq_lseek for sequential files
    // - use default_llseek if we know we access f_pos
    // - use noop_llseek if we know we don't access f_pos,
    // but we still want to allow users to call lseek
    //
    @ open1 exists @
    identifier nested_open;
    @@
    nested_open(...)
    {

    }

    @ open exists@
    identifier open_f;
    identifier i, f;
    identifier open1.nested_open;
    @@
    int open_f(struct inode *i, struct file *f)
    {

    }

    @ read disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {

    }

    @ read_no_fpos disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ write @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {

    }

    @ write_no_fpos @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ fops0 @
    identifier fops;
    @@
    struct file_operations fops = {
    ...
    };

    @ has_llseek depends on fops0 @
    identifier fops0.fops;
    identifier llseek_f;
    @@
    struct file_operations fops = {
    ...
    .llseek = llseek_f,
    ...
    };

    @ has_read depends on fops0 @
    identifier fops0.fops;
    identifier read_f;
    @@
    struct file_operations fops = {
    ...
    .read = read_f,
    ...
    };

    @ has_write depends on fops0 @
    identifier fops0.fops;
    identifier write_f;
    @@
    struct file_operations fops = {
    ...
    .write = write_f,
    ...
    };

    @ has_open depends on fops0 @
    identifier fops0.fops;
    identifier open_f;
    @@
    struct file_operations fops = {
    ...
    .open = open_f,
    ...
    };

    // use no_llseek if we call nonseekable_open
    ////////////////////////////////////////////
    @ nonseekable1 depends on !has_llseek && has_open @
    identifier fops0.fops;
    identifier nso ~= "nonseekable_open";
    @@
    struct file_operations fops = {
    ... .open = nso, ...
    +.llseek = no_llseek, /* nonseekable */
    };

    @ nonseekable2 depends on !has_llseek @
    identifier fops0.fops;
    identifier open.open_f;
    @@
    struct file_operations fops = {
    ... .open = open_f, ...
    +.llseek = no_llseek, /* open uses nonseekable */
    };

    // use seq_lseek for sequential files
    /////////////////////////////////////
    @ seq depends on !has_llseek @
    identifier fops0.fops;
    identifier sr ~= "seq_read";
    @@
    struct file_operations fops = {
    ... .read = sr, ...
    +.llseek = seq_lseek, /* we have seq_read */
    };

    // use default_llseek if there is a readdir
    ///////////////////////////////////////////
    @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier readdir_e;
    @@
    // any other fop is used that changes pos
    struct file_operations fops = {
    ... .readdir = readdir_e, ...
    +.llseek = default_llseek, /* readdir is present */
    };

    // use default_llseek if at least one of read/write touches f_pos
    /////////////////////////////////////////////////////////////////
    @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read.read_f;
    @@
    // read fops use offset
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = default_llseek, /* read accesses f_pos */
    };

    @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ... .write = write_f, ...
    + .llseek = default_llseek, /* write accesses f_pos */
    };

    // Use noop_llseek if neither read nor write accesses f_pos
    ///////////////////////////////////////////////////////////

    @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    identifier write_no_fpos.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ...
    .write = write_f,
    .read = read_f,
    ...
    +.llseek = noop_llseek, /* read and write both use no f_pos */
    };

    @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write_no_fpos.write_f;
    @@
    struct file_operations fops = {
    ... .write = write_f, ...
    +.llseek = noop_llseek, /* write uses no f_pos */
    };

    @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    @@
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = noop_llseek, /* read uses no f_pos */
    };

    @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    @@
    struct file_operations fops = {
    ...
    +.llseek = noop_llseek, /* no read or write fn */
    };
    ===== End semantic patch =====

    Signed-off-by: Arnd Bergmann
    Cc: Julia Lawall
    Cc: Christoph Hellwig

    Arnd Bergmann
     

05 Oct, 2010

1 commit

  • All these files use the big kernel lock in a trivial
    way to serialize their private file operations,
    typically resulting from an earlier semi-automatic
    pushdown from VFS.

    None of these drivers appears to want to lock against
    other code, and they all use the BKL as the top-level
    lock in their file operations, meaning that there
    is no lock-order inversion problem.

    Consequently, we can remove the BKL completely,
    replacing it with a per-file mutex in every case.
    Using a scripted approach means we can avoid
    typos.

    These drivers do not seem to be under active
    maintainance from my brief investigation. Apologies
    to those maintainers that I have missed.

    file=$1
    name=$2
    if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
    sed -i '/include.*/d' ${file}
    else
    sed -i 's/include.*.*$/include /g' ${file}
    fi
    sed -i ${file} \
    -e "/^#include.*linux.mutex.h/,$ {
    1,/^\(static\|int\|long\)/ {
    /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

    } }" \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[ ]*cycle_kernel_lock();/d'
    else
    sed -i -e '/include.*\/d' ${file} \
    -e '/cycle_kernel_lock()/d'
    fi

    Signed-off-by: Arnd Bergmann

    Arnd Bergmann
     

11 Dec, 2009

1 commit


17 Oct, 2008

1 commit


22 Jul, 2008

1 commit


21 Jun, 2008

1 commit


07 Feb, 2008

1 commit


17 Oct, 2007

1 commit


13 Oct, 2007

1 commit


09 May, 2007

3 commits

  • ROUND_UP macro cleanup use DIV_ROUND_UP

    Signed-off-by: Milind Arun Choudhary
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Milind Arun Choudhary
     
  • Remove includes of where it is not used/needed.
    Suggested by Al Viro.

    Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
    sparc64, and arm (all 59 defconfigs).

    Signed-off-by: Randy Dunlap
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Randy Dunlap
     
  • Update some of the layered parport_driver code to use parport->dev:

    - i2c-parport (parent of i2c_adapter)
    - spi_butterfly (parent of spi_master, allowing cruft removal)
    - lp (creating class_device)
    - ppdev (parent of parportN device)
    - tipar (creating class_device)

    There are still drivers that should be updated, like some of the input
    drivers; but they won't be any worse off than they are today.

    Signed-off-by: David Brownell
    Cc: Greg KH
    Cc: Jean Delvare
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Brownell
     

14 Dec, 2006

1 commit

  • Run this:

    #!/bin/sh
    for f in $(grep -Erl "\([^\)]*\) *k[cmz]alloc" *) ; do
    echo "De-casting $f..."
    perl -pi -e "s/ ?= ?\([^\)]*\) *(k[cmz]alloc) *\(/ = \1\(/" $f
    done

    And then go through and reinstate those cases where code is casting pointers
    to non-pointers.

    And then drop a few hunks which conflicted with outstanding work.

    Cc: Russell King , Ian Molton
    Cc: Mikael Starvik
    Cc: Yoshinori Sato
    Cc: Roman Zippel
    Cc: Geert Uytterhoeven
    Cc: Ralf Baechle
    Cc: Paul Mackerras
    Cc: Kyle McMartin
    Cc: Benjamin Herrenschmidt
    Cc: Martin Schwidefsky
    Cc: "David S. Miller"
    Cc: Jeff Dike
    Cc: Greg KH
    Cc: Jens Axboe
    Cc: Paul Fulghum
    Cc: Alan Cox
    Cc: Karsten Keil
    Cc: Mauro Carvalho Chehab
    Cc: Jeff Garzik
    Cc: James Bottomley
    Cc: Ian Kent
    Cc: Steven French
    Cc: David Woodhouse
    Cc: Neil Brown
    Cc: Jaroslav Kysela
    Cc: Takashi Iwai
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Robert P. J. Day
     

09 Dec, 2006

1 commit


30 Sep, 2006

1 commit


04 Jul, 2006

1 commit

  • Mark the static struct file_operations in drivers/char as const. Making
    them const prevents accidental bugs, and moves them to the .rodata section
    so that they no longer do any false sharing; in addition with the proper
    debug option they are then protected against corruption..

    [akpm@osdl.org: build fix]
    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     

01 Jul, 2006

1 commit


27 Jun, 2006

4 commits


29 Oct, 2005

1 commit


11 Sep, 2005

1 commit


21 Jun, 2005

1 commit


17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds