Due to newly-introduced 'coherency=full' O_DIRECT writes also takes the EX
rw_lock like buffered writes did(rw_level == 1), it turns out messing the
usage of 'level' in ocfs2_dio_end_io() up, which caused i_alloc_sem being
failed to get up_read'd correctly.

This patch tries to teach ocfs2_dio_end_io to understand well on all locking
stuffs by explicitly introducing a new bit for i_alloc_sem in iocb's private
data, just like what we did for rw_lock.
Signed-off-by: NTristan Ye <tristan.ye@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

o2dlm was not migrating resources with zero locks because it assumed that that
resource would get purged by dlm_thread. However, some usage patterns involve
creating and dropping locks at a high rate leading to the migrate thread seeing
zero locks but the purge thread seeing an active reference. When this happens,
the dlm_thread cannot purge the resource and the migrate thread sees no reason
to migrate that resource. The spell is broken when the migrate thread catches
the resource with a lock.

The fix is to make the migrate thread also consider the reference map.

This usage pattern can be triggered by userspace on userdlm locks and flocks.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 83fd9c7f changes l_level, l_requested and l_blocking of
ocfs2_lock_res from int to unsigned char. But actually it is
initially as -1(ocfs2_lock_res_init_common) which
correspoding to 255 for unsigned char. So the whole dlm lock
mechanism doesn't work now which means a disaster to ocfs2.

Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

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

... and switch of the obvious get_sb_bdev() users to ->mount()
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves.  For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Clones an existing reference to inode; caller must already hold one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

__block_write_begin and block_prepare_write are identical except for slightly
different calling conventions.  Convert all callers to the __block_write_begin
calling conventions and drop block_prepare_write.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit dd3932ed ("block: remove BLKDEV_IFL_WAIT") had removed the
flag argument to blkdev_issue_flush(), but the ocfs2 merge brought in a
new one.  It didn't cause a merge conflict, so the merges silently
worked out fine, but the result didn't actually compile.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It was evaludated to indexed before, check it is ok i think.
Signed-off-by: NJeff Liu <jeff.liu@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

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>

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(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ 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)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *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)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *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: NArnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>

Currently, the default behavior of O_DIRECT writes was allowing
concurrent writing among nodes to the same file, with no cluster
coherency guaranteed (no EX lock held).  This can leave stale data in
the cache for buffered reads on other nodes.

The new mount option introduce a chance to choose two different
behaviors for O_DIRECT writes:

    * coherency=full, as the default value, will disallow
                      concurrent O_DIRECT writes by taking
                      EX locks.

    * coherency=buffered, allow concurrent O_DIRECT writes
                          without EX lock among nodes, which
                          gains high performance at risk of
                          getting stale data on other nodes.
Signed-off-by: NTristan Ye <tristan.ye@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Functions such as ocfs2_recovery_init() make use of osb->max_slots.
Initialize osb->max_slots early so the functions may use the correct
value.
Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

fs/ocfs2/slot_map.c: In function ‘ocfs2_init_slot_info’:
fs/ocfs2/slot_map.c:360: warning: ‘bytes’ may be used uninitialized in this function
fs/ocfs2/slot_map.c:360: note: ‘bytes’ was declared here
Compiler: gcc version 4.4.3 (GCC) on Mandriva
I'm not sure why this warning occurs, I think compiler don't know that variable
"bytes" is initialized when it is sent by reference to
ocfs2_slot_map_physical_size and it throws that ugly warning.
However, a simple initialization of "bytes" variable with 0 will fix it.
Signed-off-by: NIonut Gabriel Popescu <poyo_vl@yahoo.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

This patch adds a safe check to ensure bg_free_bits_count doesn't exceed
bg_bits in a group descriptor. This is to avoid on disk corruption that was
seen recently.

debugfs: group <52803072>
       Group Chain: 179   Parent Inode: 11  Generation: 2959379682
       CRC32: 00000000   ECC: 0000
       ##   Block#            Total    Used     Free     Contig   Size
       0    52803072          32256    4294965350   34202    18207    4032
       ......
Signed-off-by: NSrinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@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>

Prints messages when the user adds or removes nodes.
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/dlm: Add message DLM_QUERY_NODEINFO

Adds new dlm message DLM_QUERY_NODEINFO that sends the attributes of all
registered nodes. This message is sent if the negotiated dlm protocol is
1.1 or higher. If the information of the joining node does not match
that of any existing nodes, the join domain request is rejected.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2: Print message if user mounts without starting global heartbeat

In global heartbeat mode, the heartbeat is started by the user. This patch
prints an error if the user attempts to mount a volume without starting the
heartbeat.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2/dlm: Add message DLM_QUERY_REGION

Adds new dlm message DLM_QUERY_REGION that sends the names of all active
heartbeat regions. This message is only sent in the global heartbeat
mode. If the regions in the joining node do not fully match the ones in
the active nodes, the join domain request is rejected.
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/dlm: Expose dlm_protocol in dlm_state

Add dlm_protocol to the list of info shown by the debugfs file, dlm_state.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2: Add support for heartbeat=global mount option

Adds support for heartbeat=global mount option. It ensures that the heartbeat
mode passed matches the one enabled on disk.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

ocfs2: Add an incompat feature flag OCFS2_FEATURE_INCOMPAT_CLUSTERINFO

OCFS2_FEATURE_INCOMPAT_CLUSTERINFO allows us to use sb->s_cluster_info for
both userspace and o2cb cluster stacks. It also allows us to extend cluster
info to include stack flags.

This patch also adds stackflags to sb->s_clusterinfo. It also introduces a
clusterinfo flag OCFS2_CLUSTER_O2CB_GLOBAL_HEARTBEAT to denote the enabled
global heartbeat mode.

This incompat flag can be set/cleared using tunefs.ocfs2 --fs-features. The
clusterinfo flag is set/cleared using tunefs.ocfs2 --update-cluster-stack.
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>

The BKL in ocfs2/dlmfs is used in put_super, fill_super and remount_fs
that are all three protected by the superblocks s_umount rw_semaphore.

The use in ocfs2_control_open is evidently unrelated and the function
is protected by ocfs2_control_lock.

Therefore it is safe to remove the BKL entirely.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>