There may exist NULL pointer dereference in config_item_name() when one
volume (say Volume A) unmounts while another (say Volume B) mounting.

     Volume A                          Volume B

  already Mounted.
  Unmounting, call
  o2hb_heartbeat_group_drop_item()
    -> config_item_put(item)
    set reg(A)->item.ci_name to NULL
    in function config_item_cleanup().

                                    begin mounting, call
                                    o2hb_region_pin() and tranverse all
                                    regions. When reading
                                    reg(A)->item.ci_name, it causes
                                    NULL pointer dereference.

  call o2hb_region_release() and
  del reg(A) from list.

So we should skip accessing regions that is going to release when
tranverse o2hb_all_regions.
Signed-off-by: NYiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: Njoyce <xuejiufei@huawei.com>
Acked-by: NJoel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

s/o2hb_global_hearbeat_mode_set/o2hb_global_heartbeat_mode_set/ to make
the signature of those routines in a consistent manner with others for
heartbeating.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Acked-by: NSunil Mushran <sunil.mushran@gmail.com>
Cc: Gurudas Pai <gurudas.pai@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
Cc: Srinivas Eeeda <srinivas.eeda@oracle.com>
Cc: Tao Ma <tm@tao.ma>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Under heavy I/O load, writing the disk heartbeat can be forced to wait for
minutes, and this causes the node to be fenced.

This patch tries to use WRITE_SYNC in submitting the heartbeat bio, so
that writing the heartbeat will have a priority over other requests.
Signed-off-by: NNoboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
Acked-by: NTao Ma <tm@tao.ma>
Acked-by: NSunil Mushran <sunil.mushran@gmail.com>
Cc: Srinivas Eeeda <srinivas.eeda@oracle.com>
Reviewed-by: NJie Liu <jeff.liu@oracle.com>
Tested-by: NGurudas Pai <gurudas.pai@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

smatch analysis indicates a number of redundant NULL checks before
calling kfree(), eg:

  fs/ocfs2/alloc.c:6138 ocfs2_begin_truncate_log_recovery() info:
   redundant null check on *tl_copy calling kfree()

  fs/ocfs2/alloc.c:6755 ocfs2_zero_range_for_truncate() info:
   redundant null check on pages calling kfree()

etc....

[akpm@linux-foundation.org: revert dubious change in ocfs2_begin_truncate_log_recovery()]
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: NJoel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The o2hb debugfs file, elapsed_time_in_ms, should return values only after the
timer is armed atleast once.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

Currently if the heartbeat device is hard-ro, the o2hb thread keeps chugging
along and dumping errors along the way. The user needs to manually stop the
heartbeat.

The patch addresses this shortcoming by adding a limit to the number of times
the hb thread will iterate in an unsteady state. If the hb thread does not
ready steady state in that many interation, the start is aborted.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

If o2hb finds unexpected values in the heartbeat slot, it prints a message
"ERROR: Device "dm-6": another node is heartbeating in our slot!"

This message could be misleading. This patch adds two more messages to
help users better diagnose the problem.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Acked-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

We have seen isolated cases (very few, I might add) of o2hb not detecting all
live nodes on startup. One plausible reasoning for it is that other node had
a hb io delay at the same time. The live threshold set at 2 (as low as it can
be) could be increased to ameliorate the situation.

But increasing the threshold directly affects mount time. Currently it takes
around 5 secs to mount a volume in o2cb cluster with local heartbeat. Increasing
the threshold will make mounts even slower. As the issue itself is rare, we have
left things as they are for the local heartbeat mode.

However we can improve the situation for global heartbeat mode as in that mode,
we start the heartbeat much before the mount.

This patch doubles the live threshold for the start of the first region in
global heartbeat mode.

Addresses internal Oracle bug#10635585.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Acked-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

mlog_exit is used to record the exit status of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.

This patch just try to remove it or change it. So:
1. if all the error paths already use mlog_errno, it is just removed.
   Otherwise, it will be replaced by mlog_errno.
2. if it is used to print some return value, it is replaced with
   mlog(0,...).
mlog_exit_ptr is changed to mlog(0.
All those mlog(0,...) will be replaced with trace events later.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>

ENTRY is used to record the entry of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.

So for mlog_entry_void, we just remove it.
for mlog_entry(...), we replace it with mlog(0,...), and they
will be replace by trace event later.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>

flush_scheduled_work() is deprecated and scheduled to be removed.

* cancel_delayed_work() + flush_schedule_work() ->
  cancel_delayed_work_sync().

* flush qs->qs_work directly on exit instead.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NJoel Becker <joel.becker@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>

The patch pins the node item of the local node when the o2hb thread
starts and unpins on stop.

An earlier patch pinned the node item of the remote node on o2net
connect and unpinned on disconnect.

Signed-off-by Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

This patch adds a per o2hb region debugfs file that shows whether that region
is pinned or not.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

This patch adds support for pinning o2hb regions in configfs. Pinning disallows
a region to be cleanly stopped as long as it has an active dependent user
(read o2dlm).

In local heartbeat mode, the region uuid matching the domain name is pinned as
long as the o2dlm domain is active.

In global heartbeat mode, all regions are pinned as long as there is atleast
one dependent user and the region count is 3 or less. All regions are unpinned
if the number of dependent users is zero or region count is greater than 3.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Patch removes a dropped region from the quorum region bitmap maintained by o2hb.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Stanse found that o2hb_heartbeat_group_make_item leaks some memory on
fail paths. Fix the paths by adding a new label and jump there.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: ocfs2-devel@oss.oracle.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.

* blkdev_get/put() are the primary open and close functions.

* bd_claim/release() deal with exclusive open.

* open/close_bdev_exclusive() are combination of open and claim and
  the other way around, respectively.

* bd_link/unlink_disk_holder() to create and remove holder/slave
  symlinks.

* open_by_devnum() wraps bdget() + blkdev_get().

The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access.  Reorganize the interface such that,

* blkdev_get() is extended to include exclusive access management.
  @holder argument is added and, if is @FMODE_EXCL specified, it will
  gain exclusive access atomically w.r.t. other exclusive accesses.

* blkdev_put() is similarly extended.  It now takes @mode argument and
  if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
  the last exclusive claim is released, the holder/slave symlinks are
  removed automatically.

* bd_claim/release() and close_bdev_exclusive() are no longer
  necessary and either made static or removed.

* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
  is no longer necessary and removed.

* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
  and blkdev_get().  It also has an unexpected extra bdev_read_only()
  test which probably should be moved into blkdev_get().

* open_by_devnum() is modified to take @holder argument and pass it to
  blkdev_get().

Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should).  This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.

open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features.  Well, let's leave them for another day.

Most conversions are straight-forward.  drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NNeil Brown <neilb@suse.de>
Acked-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: NMike Snitzer <snitzer@redhat.com>
Acked-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>

ocfs2/cluster: Release debugfs file elapsed_time_in_ms

An earlier commit forgot to remove a debugfs file, elapsed_time_in_ms.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

dlm protocol 1.1. activates messages DLM_QUERY_REGION and DLM_QUERY_NODEINFO
that are a must for global heartbeat.

It also activates o2hb_global_heartbeat_active().
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Show per region heartbeat elapsed time

This patch adds a per region debugfs file that shows the elapsed time
since the time the o2hb timer was last armed.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Add mlogs for heartbeat up/down events

This patch adds mlogs for o2hb up and down events.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Create debugfs dir/files for each region

This patch creates debugfs directory for each o2hb region and creates
files to expose the region number and the per region live node bitmap.
This information will be useful in debugging cluster issues.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Create debugfs files for live, quorum and failed region bitmaps

This patch prints the bitmaps of live, quorum and failed regions. This
information will be useful in debugging cluster issues.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Maintain bitmap of failed regions

In global heartbeat mode, we track the bitmap of regions that have seen
heartbeat timeouts. We fence if the number of such regions is greater than
or equal to half the number of quorum regions.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Maintain bitmap of quorum regions

o2hb allows online adding of regions. However, a newly added region is not
used in quorum calculations unless it has been added on all nodes. This patch
tracks a bitmap of such quorum regions.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Track bitmap of live heartbeat regions

A heartbeat region becomes live (or active) after a fixed number of (steady)
iterations.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Track number of global heartbeat regions

In global heartbeat mode, we have a upper limit for the number of active regions.
This patch adds the facility to track the number of active global heartbeat
regions and fails to start heartbeat if the number exceeds the maximum.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Maintain live node bitmap per heartbeat region

Currently we track a global livenode bitmap that keeps track of all nodes
that are heartbeating in all regions.

This patch adds the ability to track the livenode bitmap on a per region basis.
We will use this facility in a later patch to allow us to withstand the loss of
a minority number of regions.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Reorganize o2hb debugfs init

o2hb debugfs handling is reorganized to allow for easy expansion.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Check slots for unconfigured live nodes

o2hb currently checks slots for configured nodes only. This patch makes
it check the slots for the live nodes too to take care of a race in which
a node is removed from the configuration but not from the live map.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Print messages when adding/removing heartbeat regions

Prints messages when the user adds or removes heartbeat regions in global
heartbeat mode. These messages are useful when debugging cluster related issues.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Get all heartbeat regions

Export function in o2hb to get a list of heartbeat regions. It also adds an
upper limit to the length of the heartbeat region name.

o2hb_global_heartbeat_active() currently disables global heartbeat. It will
be enabled in a later patch after all the code is added.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/cluster: Add heartbeat mode configfs parameter

Add heartbeat mode parameter to the configfs tree. This will be used
to set/show the heartbeat mode. The user is free to toggle the mode
between local and global as long as there is no active heartbeat region.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

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>

Patch removes trailing whitespaces.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

I just noticed today that there are 2 places of "mlog(0,...)"
in  fs/ocfs2/cluster/heartbeat.c, but actually have no default
mask prefix in that file.
So change them to mlog(ML_HEARTBEAT,...).
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>