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: NDavid Teigland <teigland@redhat.com>

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: NDavid Teigland <teigland@redhat.com>

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: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The rwlock is almost always used in write mode, so there's no reason
to not use a spinlock instead.
Signed-off-by: NDavid Teigland <teigland@redhat.com>

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: NDavd Teigland <teigland@redhat.com>

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: NDavid Teigland <teigland@redhat.com>

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: NDavid Teigland <teigland@redhat.com>

it moves 365 bytes from .text to .init.text, and 30 bytes from .text to
.exit.text, saves memory.
Signed-off-by: NDenis Cheng <crquan@gmail.com>
Signed-off-by: NDavid Teigland <teigland@redhat.com>

Put lkb_astparam in a union with a dlm_user_args pointer to
eliminate a lot of type casting.
Signed-off-by: NDavid Teigland <teigland@redhat.com>

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: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

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: NJosef Bacik <jwhiter@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

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: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

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: NJosef Bacik <jwhiter@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

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: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

When the debug buffer has filled up, break from the loop and return the
correct number of bytes that have been written.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

> 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: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

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: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Display more information from debugfs, particularly locks waiting for
a master lookup or operations waiting for a remote reply.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch removes support for range locking from the DLM
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteve Whitehouse <swhiteho@redhat.com>

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: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteve Whitehouse <swhiteho@redhat.com>