08 Aug, 2017

3 commits


20 Oct, 2016

1 commit

  • Historically a lot of these existed because we did not have
    a distinction between what was modular code and what was providing
    support to modules via EXPORT_SYMBOL and friends. That changed
    when we forked out support for the latter into the export.h file.
    This means we should be able to reduce the usage of module.h
    in code that is obj-y Makefile or bool Kconfig.

    In the case of some code where it is modular, we can extend that to
    also include files that are building basic support functionality but
    not related to loading or registering the final module; such files
    also have no need whatsoever for module.h

    The advantage in removing such instances is that module.h itself
    sources about 15 other headers; adding significantly to what we feed
    cpp, and it can obscure what headers we are effectively using.

    Since module.h might have been the implicit source for init.h
    (for __init) and for export.h (for EXPORT_SYMBOL) we consider each
    instance for the presence of either and replace as needed.

    In the dlm case, we remove module.h from a global header and only
    introduce it in the files where it is explicitly required, since
    there is nothing modular in dlm_internal.h itself.

    Signed-off-by: Paul Gortmaker
    Signed-off-by: David Teigland

    Paul Gortmaker
     

27 Aug, 2016

1 commit

  • With the current kernel, `dlm_tool lockdebug` fails as below:

    "dlm_tool lockdebug ED0BD86DCE724393918A1AE8FDBF1EE3
    can't open /sys/kernel/debug/dlm/ED0BD86DCE724393918A1AE8FDBF1EE3:
    Operation not permitted"

    This is because table_open() depends on file->f_op to tell which
    seq_file ops should be passed down. But, the original file ops in
    file->f_op is replaced by "debugfs_full_proxy_file_operations" with
    commit 49d200deaa68 ("debugfs: prevent access to removed files'
    private data").

    Currently, I can think up 2 solutions: 1st, replace
    debugfs_create_file() with debugfs_create_file_unsafe();
    2nd, make different table_open#() accordingly. The 1st one
    is neat, but I don't thoroughly understand its risk. Maybe
    someone has a better one.

    Signed-off-by: Eric Ren
    Signed-off-by: David Teigland

    Eric Ren
     

06 Nov, 2014

2 commits

  • Convert the seq_printf output with constant strings to seq_puts.

    Link: http://lkml.kernel.org/p/b416b016f4a6e49115ba736cad6ea2709a8bc1c4.1412031505.git.joe@perches.com

    Cc: Christine Caulfield
    Cc: David Teigland
    Cc: cluster-devel@redhat.com
    Signed-off-by: Joe Perches
    Signed-off-by: Steven Rostedt

    Joe Perches
     
  • The seq_printf() return is going away soon and users of it should
    check seq_has_overflowed() to see if the buffer is full and will
    not accept any more data.

    Convert functions returning int to void where seq_printf() is used.

    Link: http://lkml.kernel.org/p/43590057bcb83846acbbcc1fe641f792b2fb7773.1412031505.git.joe@perches.com
    Link: http://lkml.kernel.org/r/20141029220107.939492048@goodmis.org

    Acked-by: David Teigland
    Cc: Christine Caulfield
    Cc: cluster-devel@redhat.com
    Signed-off-by: Joe Perches
    Signed-off-by: Steven Rostedt

    Joe Perches
     

09 Aug, 2014

1 commit


07 Jun, 2014

1 commit


17 Jul, 2012

1 commit

  • Remove the dir hash table (dirtbl), and use
    the rsb hash table (rsbtbl) as the resource
    directory. It has always been an unnecessary
    duplication of information.

    This improves efficiency by using a single rsbtbl
    lookup in many cases where both rsbtbl and dirtbl
    lookups were needed previously.

    This eliminates the need to handle cases of rsbtbl
    and dirtbl being out of sync.

    In many cases there will be memory savings because
    the dir hash table no longer exists.

    Signed-off-by: David Teigland

    David Teigland
     

06 Apr, 2012

1 commit

  • Many users of debugfs copy the implementation of default_open() when
    they want to support a custom read/write function op. This leads to a
    proliferation of the default_open() implementation across the entire
    tree.

    Now that the common implementation has been consolidated into libfs we
    can replace all the users of this function with simple_open().

    This replacement was done with the following semantic patch:

    @ open @
    identifier open_f != simple_open;
    identifier i, f;
    @@
    -int open_f(struct inode *i, struct file *f)
    -{
    (
    -if (i->i_private)
    -f->private_data = i->i_private;
    |
    -f->private_data = i->i_private;
    )
    -return 0;
    -}

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

    [akpm@linux-foundation.org: checkpatch fixes]
    Signed-off-by: Stephen Boyd
    Cc: Greg Kroah-Hartman
    Cc: Al Viro
    Cc: Julia Lawall
    Acked-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Stephen Boyd
     

19 Nov, 2011

1 commit

  • Change the linked lists to rb_tree's in the rsb
    hash table to speed up searches. Slow rsb searches
    were having a large impact on gfs2 performance due
    to the large number of dlm locks gfs2 uses.

    Signed-off-by: Bob Peterson
    Signed-off-by: David Teigland

    Bob Peterson
     

11 Mar, 2011

1 commit

  • Change how callbacks are recorded for locks. Previously, information
    about multiple callbacks was combined into a couple of variables that
    indicated what the end result should be. In some situations, we
    could not tell from this combined state what the exact sequence of
    callbacks were, and would end up either delivering the callbacks in
    the wrong order, or suppress redundant callbacks incorrectly. This
    new approach records all the data for each callback, leaving no
    uncertainty about what needs to be delivered.

    Signed-off-by: David Teigland

    David Teigland
     

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
     

30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

27 Feb, 2010

1 commit

  • The bast mode that appears in the debugfs output should be
    useful on both master and process nodes. lkb_highbast is
    currently printed, and is only useful on the master node.
    lkb_bastmode is only useful on the process node. This
    patch sets lkb_bastmode on the master node as well, and
    uses that value in the debugfs print.

    Signed-off-by: David Teigland

    David Teigland
     

01 Dec, 2009

1 commit

  • Replace all GFP_KERNEL and ls_allocation with GFP_NOFS.
    ls_allocation would be GFP_KERNEL for userland lockspaces
    and GFP_NOFS for file system lockspaces.

    It was discovered that any lockspaces on the system can
    affect all others by triggering memory reclaim in the
    file system which could in turn call back into the dlm
    to acquire locks, deadlocking dlm threads that were
    shared by all lockspaces, like dlm_recv.

    Signed-off-by: David Teigland

    David Teigland
     

23 Sep, 2009

1 commit

  • Make all seq_operations structs const, to help mitigate against
    revectoring user-triggerable function pointers.

    This is derived from the grsecurity patch, although generated from scratch
    because it's simpler than extracting the changes from there.

    Signed-off-by: James Morris
    Acked-by: Serge Hallyn
    Acked-by: Casey Schaufler
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    James Morris
     

09 Jan, 2009

2 commits

  • The rwlock is almost always used in write mode, so there's no reason
    to not use a spinlock instead.

    Signed-off-by: David Teigland

    David Teigland
     
  • The old code would leak iterators and leave reference counts on
    rsbs because it was ignoring the "stop" seq callback. The code
    followed an example that used the seq operations differently.
    This new code is based on actually understanding how the seq
    operations work. It also improves things by saving the hash bucket
    in the position to avoid cycling through completed buckets in start.

    Siged-off-by: Davd Teigland

    David Teigland
     

24 Dec, 2008

2 commits

  • The new debugfs entry dumps all rsb and lkb structures, and includes
    a lot more information than has been available before. This includes
    the new timestamps added by a previous patch for debugging callback
    issues.

    Signed-off-by: David Teigland

    David Teigland
     
  • Use ktime instead of jiffies for timestamping lkb's. Also stamp the
    time on every lkb whenever it's added to a resource queue, instead of
    just stamping locks subject to timeouts. This will allow us to use
    timestamps more widely for debugging all locks.

    Signed-off-by: David Teigland

    David Teigland
     

07 Feb, 2008

2 commits


09 Jul, 2007

4 commits

  • Add two more output fields (lkb_flags and rsb nodeid) to the new debugfs
    file that dumps one lock per line. Also, dump all locks instead of just
    mastered locks. Accordingly, use a suffix of _locks instead of _master.

    Signed-off-by: David Teigland
    Signed-off-by: Steven Whitehouse

    David Teigland
     
  • This is a fix for the patch

    021d2ff3a08019260a1dc002793c92d6bf18afb6

    I left off a dlm_hold_rsb which causes the box to panic if you try to use
    debugfs. This patch fixes the problem. Sorry about that,

    Signed-off-by: Josef Bacik
    Signed-off-by: Steven Whitehouse

    Josef Bacik
     
  • Add a new debugfs file that dumps a compact list of mastered locks.
    This will be used by a userland daemon to collect state for deadlock
    detection.

    Also, for the existing function that prints all lock state, lock the rsb
    before going through the lock lists since they can be changing in the
    course of normal dlm activity.

    Signed-off-by: David Teigland
    Signed-off-by: Steven Whitehouse

    David Teigland
     
  • This problem was originally reported against GFS6.1, but the same issue exists
    in upstream DLM. This patch keeps the rsb iterator assigning under the rsbtbl
    list lock. Each time we process an rsb we grab a reference to it to make sure
    it is not freed out from underneath us, and then put it when we get the next rsb
    in the list or move onto another list.

    Signed-off-by: Josef Bacik
    Signed-off-by: Steven Whitehouse

    Josef Bacik
     

13 Feb, 2007

1 commit

  • Many struct file_operations in the kernel can be "const". Marking them const
    moves these to the .rodata section, which avoids false sharing with potential
    dirty data. In addition it'll catch accidental writes at compile time to
    these shared resources.

    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     

28 Sep, 2006

1 commit

  • The following patches reduce the size of the VFS inode structure by 28 bytes
    on a UP x86. (It would be more on an x86_64 system). This is a 10% reduction
    in the inode size on a UP kernel that is configured in a production mode
    (i.e., with no spinlock or other debugging functions enabled; if you want to
    save memory taken up by in-core inodes, the first thing you should do is
    disable the debugging options; they are responsible for a huge amount of bloat
    in the VFS inode structure).

    This patch:

    The filesystem or device-specific pointer in the inode is inside a union,
    which is pretty pointless given that all 30+ users of this field have been
    using the void pointer. Get rid of the union and rename it to i_private, with
    a comment to explain who is allowed to use the void pointer. This is just a
    cleanup, but it allows us to reuse the union 'u' for something something where
    the union will actually be used.

    Signed-off-by: "Theodore Ts'o"
    Cc: Steven Whitehouse
    Signed-off-by: Andrew Morton

    Theodore Ts'o
     

09 Aug, 2006

1 commit


27 Jul, 2006

2 commits

  • > I think you must have an old version of the base kernel as well?
    > i_private no longer exists in struct inode, so you'll have to use
    > something else,

    I have that patch in my stack but didn't send it; for some reason I
    thought it was already changed in your git tree.

    Signed-off-by: David Teigland
    Signed-off-by: Steven Whitehouse

    David Teigland
     
  • On Wed, Jul 26, 2006 at 10:47:14AM +0100, Steven Whitehouse wrote:
    > Hi,
    >
    > I've applied all the patches you sent, but they don't build:

    Argh, sorry about that... when I fixed these a long time ago they somehow
    never got included in the quilt patches. I mistakenly assumed the quilt
    patches matched the source I had in front of me.

    Signed-off-by: David Teigland
    Signed-off-by: Steven Whitehouse

    David Teigland
     

26 Jul, 2006

1 commit


23 Feb, 2006

1 commit


20 Jan, 2006

1 commit


18 Jan, 2006

1 commit

  • This is the core of the distributed lock manager which is required
    to use GFS2 as a cluster filesystem. It is also used by CLVM and
    can be used as a standalone lock manager independantly of either
    of these two projects.

    It implements VAX-style locking modes.

    Signed-off-by: David Teigland
    Signed-off-by: Steve Whitehouse

    David Teigland