include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit 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: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

With the full ocfs2_locking_protocol hanging off of the
ocfs2_cluster_connection, ast wrappers can get the ast/bast pointers
there.  They don't need to get them from their plugin structure.

The user plugin still needs the maximum locking protocol version,
though.  This changes the plugin structure so that it only holds the max
version, not the entire ocfs2_locking_protocol pointer.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

With the ocfs2_cluster_connection hanging off of the ocfs2_dlm_lksb, we
have access to it in the ast and bast wrapper functions.  Attach the
ocfs2_locking_protocol to the conn.

Now, instead of refering to a static variable for ast/bast pointers, the
wrappers can look at the connection.  This means different connections
can have different ast/bast pointers, and it reduces the need for the
static pointer.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

We're going to want it in the ast functions, so we convert union
ocfs2_dlm_lksb to struct ocfs2_dlm_lksb and let it carry the connection.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

The stackglue ast and bast functions tried to maintain the fiction that
their arguments were void pointers.  In reality, stack_user.c had to
know that the argument was an ocfs2_lock_res in order to get the status
off of the lksb.  That's ugly.

This changes stackglue to always pass the lksb as the argument to ast
and bast functions.  The caller can always use container_of() to get the
ocfs2_lock_res or user_dlm_lock_res.  The net effect to the caller is
zero.  They still get back the lockres in their ast.  stackglue gets
cleaner, and now can use the lksb itself.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

This patch explicitly declares an uninitialized local variable in user_cluster_connect(), to remove a compiling warning.
Signed-off-by: NColy Li <coly.li@suse.de>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

The Lock Value Block (LVB) of a DLM lock can be lost when nodes die and
the DLM cannot reconstruct its state.  Clients of the DLM need to know
this.

ocfs2's internal DLM, o2dlm, explicitly zeroes out the LVB when it loses
track of the state.  This is not a standard behavior, but ocfs2 has
always relied on it.  Thus, an o2dlm LVB is always "valid".

ocfs2 now supports both o2dlm and fs/dlm via the stack glue.  When
fs/dlm loses track of an LVBs state, it sets a flag
(DLM_SBF_VALNOTVALID) on the Lock Status Block (LKSB).  The contents of
the LVB may be garbage or merely stale.

ocfs2 doesn't want to try to guess at the validity of the stale LVB.
Instead, it should be checking the VALNOTVALID flag.  As this is the
'standard' way of treating LVBs, we will promote this behavior.

We add a stack glue API ocfs2_dlm_lvb_valid().  It returns non-zero when
the LVB is valid.  o2dlm will always return valid, while fs/dlm will
check VALNOTVALID.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Acked-by: NMark Fasheh <mfasheh@suse.com>

The locking_state dump, ocfs2_dlm_seq_show, reads the lvb on locks where it
has not yet been initialized by a lock call.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Acked-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This is actually pretty easy since fs/dlm already handles the bulk of the
work. The Ocfs2 userspace cluster stack module already uses fs/dlm as the
underlying lock manager, so I only had to add the right calls.

Cluster-aware POSIX locks ("plocks") can be turned off by the same means at
UNIX locks - mount with 'noflocks', or create a local-only Ocfs2 volume.
Internally, the file system uses two sets of file_operations, depending on
whether cluster aware plocks is required. This turns out to be easier than
implementing local-only versions of ->lock.
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The ->hangup() call was only used to execute ocfs2_hb_ctl.  Now that
the generic stack glue code handles this, the underlying stack drivers
don't need to know about it.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The static structure describing the userspace cluster plugin for ocfs2
was named 'user_stack', which is a real pain when people are grep(1)ing
the tree for the program stack object 'user_stack'.  Change the name to
something distinct and namespaced.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This patch makes the needlessly global struct ocfs2_control_device
static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Add code to use fs/dlm.

[ Modified to be part of the stack_user module -- Joel ]
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The "SETV" message sets the filesystem locking protocol version as
negotiated by the client.  The client negotiates based on the maximum
version advertised in /sys/fs/ocfs2/max_locking_protocol.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This is the second part of the ocfs2_control handshake.  After
negotiating the ocfs2_control protocol, the daemon tells the filesystem
what the local node id is via the SETN message.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

When the control daemon sees a node go down, it sends a DOWN message
through the ocfs2_control device.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

When a control daemon opens the ocfs2_control device, it must perform a
handshake to tell the filesystem it is something capable of monitoring
cluster status.  Only after the handshake is complete will the filesystem
allow mounts.

This is the first part of the handshake.  The daemon reads all supported
ocfs2_control protocols, then writes in the protocol it will use.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

The ocfs2_control misc device is how a userspace control daemon (controld)
talks to the filesystem.  Introduce the bare-bones filesystem ops.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

Add a skeleton for the stack_user module.  It's just the barebones module
code.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>