gfs2: No longer use 'extern' in function declarations

For non-static function declarations, external linkage is implied and
the 'extern' keyword isn't needed. Some static checkers complain about
the overuse of 'extern', so clean up all the function declarations.

In addition, remove 'extern' from the definition of
free_local_statfs_inodes(); it isn't needed there, either.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: move gfs2_xattr_handlers_max to .rodata

This makes it harder for accidental or malicious changes to
gfs2_xattr_handlers_max at runtime.

Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: cluster-devel@redhat.com
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230930050033.41174-13-wedsonaf@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

gfs2: Fix asynchronous thread destruction

The kernel threads are currently stopped and destroyed synchronously by
gfs2_make_fs_ro() and gfs2_put_super(), and asynchronously by
signal_our_withdraw(), with no synchronization, so the synchronous and
asynchronous contexts can race with each other.

First, when creating the kernel threads, take an extra task struct
reference so that the task struct won't go away immediately when they
terminate. This allows those kthreads to terminate immediately when
they're done rather than hanging around as zombies until they are reaped
by kthread_stop(). When kthread_stop() is called on a terminated
kthread, it will return immediately.

Second, in signal_our_withdraw(), once the SDF_JOURNAL_LIVE flag has
been cleared, wake up the logd and quotad wait queues instead of
stopping the logd and quotad kthreads. The kthreads are then expected
to terminate automatically within short time, but if they cannot, they
will not block the withdraw.

For example, if a user process and one of the kthread decide to withdraw
at the same time, only one of them will perform the actual withdraw and
the other will wait for it to be done. If the kthread ends up being the
one to wait, the withdrawing user process won't be able to stop it.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Rework freeze / thaw logic

So far, at mount time, gfs2 would take the freeze glock in shared mode
and then immediately drop it again, turning it into a cached glock that
can be reclaimed at any time. To freeze the filesystem cluster-wide,
the node initiating the freeze would take the freeze glock in exclusive
mode, which would cause the freeze glock's freeze_go_sync() callback to
run on each node. There, gfs2 would freeze the filesystem and schedule
gfs2_freeze_func() to run. gfs2_freeze_func() would re-acquire the
freeze glock in shared mode, thaw the filesystem, and drop the freeze
glock again. The initiating node would keep the freeze glock held in
exclusive mode. To thaw the filesystem, the initiating node would drop
the freeze glock again, which would allow gfs2_freeze_func() to resume
on all nodes, leaving the filesystem in the thawed state.

It turns out that in freeze_go_sync(), we cannot reliably and safely
freeze the filesystem. This is primarily because the final unmount of a
filesystem takes a write lock on the s_umount rw semaphore before
calling into gfs2_put_super(), and freeze_go_sync() needs to call
freeze_super() which also takes a write lock on the same semaphore,
causing a deadlock. We could work around this by trying to take an
active reference on the super block first, which would prevent unmount
from running at the same time. But that can fail, and freeze_go_sync()
isn't actually allowed to fail.

To get around this, this patch changes the freeze glock locking scheme
as follows:

At mount time, each node takes the freeze glock in shared mode. To
freeze a filesystem, the initiating node first freezes the filesystem
locally and then drops and re-acquires the freeze glock in exclusive
mode. All other nodes notice that there is contention on the freeze
glock in their go_callback callbacks, and they schedule
gfs2_freeze_func() to run. There, they freeze the filesystem locally
and drop and re-acquire the freeze glock before re-thawing the
filesystem. This is happening outside of the glock state engine, so
there, we are allowed to fail.

From a cluster point of view, taking and immediately dropping a glock is
indistinguishable from taking the glock and only dropping it upon
contention, so this new scheme is compatible with the old one.

Thanks to Li Dong <lidong@vivo.com> for reporting a locking bug in
gfs2_freeze_func() in a previous version of this commit.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Don't release and reacquire local statfs bh

Before this patch, several functions in gfs2 related to the updating
of the statfs file used a newly acquired/read buffer_head for the
local statfs file. This is completely unnecessary, because other nodes
should never update it. Recreating the buffer is a waste of time.

This patch allows gfs2 to read in the local statefs buffer_head at
mount time and keep it around until unmount time.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: make function gfs2_make_fs_ro() to void type

It fixes the following warning detected by coccinelle:
./fs/gfs2/super.c:592:5-10: Unneeded variable: "error". Return "0" on
line 628

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Add trusted xattr support

Add support for an additional filesystem version (sb_fs_format = 1802).
When a filesystem with the new version is mounted, the filesystem
supports "trusted.*" xattrs.

In addition, version 1802 filesystems implement a form of forward
compatibility for xattrs: when xattrs with an unknown prefix (ea_type)
are found on a version 1802 filesystem, those attributes are not shown
by listxattr, and they are not accessible by getxattr, setxattr, or
removexattr.

This mechanism might turn out to be what we need in the future, but if
not, we can always bump the filesystem version and break compatibility
instead.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Andrew Price <anprice@redhat.com>

gfs2: Enable rgrplvb for sb_fs_format 1802

Turn on rgrplvb by default for sb_fs_format > 1801.

Mount options still have to override this so a new args field to
differentiate between 'off' and 'not specified' is added, and the new
default is applied only when it's not specified.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: lookup local statfs inodes prior to journal recovery

We need to lookup the master statfs inode and the local statfs
inodes earlier in the mount process (in init_journal) so journal
recovery can use them when it attempts to recover the statfs info.
We lookup all the local statfs inodes and store them in a linked
list to allow a node to recover statfs info for other nodes in the
cluster.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Add fields for statfs info in struct gfs2_log_header_host

And read these in __get_log_header() from the log header.
Also make gfs2_statfs_change_out() non-static so it can be used
outside of super.c

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Force withdraw to replay journals and wait for it to finish

When a node withdraws from a file system, it often leaves its journal
in an incomplete state. This is especially true when the withdraw is
caused by io errors writing to the journal. Before this patch, a
withdraw would try to write a "shutdown" record to the journal, tell
dlm it's done with the file system, and none of the other nodes
know about the problem. Later, when the problem is fixed and the
withdrawn node is rebooted, it would then discover that its own
journal was incomplete, and replay it. However, replaying it at this
point is almost guaranteed to introduce corruption because the other
nodes are likely to have used affected resource groups that appeared
in the journal since the time of the withdraw. Replaying the journal
later will overwrite any changes made, and not through any fault of
dlm, which was instructed during the withdraw to release those
resources.

This patch makes file system withdraws seen by the entire cluster.
Withdrawing nodes dequeue their journal glock to allow recovery.

The remaining nodes check all the journals to see if they are
clean or in need of replay. They try to replay dirty journals, but
only the journals of withdrawn nodes will be "not busy" and
therefore available for replay.

Until the journal replay is complete, no i/o related glocks may be
given out, to ensure that the replay does not cause the
aforementioned corruption: We cannot allow any journal replay to
overwrite blocks associated with a glock once it is held.

The "live" glock which is now used to signal when a withdraw
occurs. When a withdraw occurs, the node signals its withdraw by
dequeueing the "live" glock and trying to enqueue it in EX mode,
thus forcing the other nodes to all see a demote request, by way
of a "1CB" (one callback) try lock. The "live" glock is not
granted in EX; the callback is only just used to indicate a
withdraw has occurred.

Note that all nodes in the cluster must wait for the recovering
node to finish replaying the withdrawing node's journal before
continuing. To this end, it checks that the journals are clean
multiple times in a retry loop.

Also note that the withdraw function may be called from a wide
variety of situations, and therefore, we need to take extra
precautions to make sure pointers are valid before using them in
many circumstances.

We also need to take care when glocks decide to withdraw, since
the withdraw code now uses glocks.

Also, before this patch, if a process encountered an error and
decided to withdraw, if another process was already withdrawing,
the second withdraw would be silently ignored, which set it free
to unlock its glocks. That's correct behavior if the original
withdrawer encounters further errors down the road. But if
secondary waiters don't wait for the journal replay, unlocking
glocks will allow other nodes to use them, despite the fact that
the journal containing those blocks is being replayed. The
replay needs to finish before our glocks are released to other
nodes. IOW, secondary withdraws need to wait for the first
withdraw to finish.

For example, if an rgrp glock is unlocked by a process that didn't
wait for the first withdraw, a journal replay could introduce file
system corruption by replaying a rgrp block that has already been
granted to a different cluster node.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Convert gfs2 to fs_context

Convert gfs2 and gfs2meta to fs_context. Removes the duplicated vfs code
from gfs2_mount and instead uses the new vfs_get_block_super() before
switching the ->root to the appropriate dentry.

The mount option parsing has been converted to the new API and error
reporting for invalid options has been made more precise at the same
time.

All of the mount/remount code has been moved into ops_fstype.c

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: cluster-devel@redhat.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

gfs2: Clean up freeing struct gfs2_sbd

Add a free_sbd function for freeing a struct gfs2_sbd. Use that for
freeing a super-block descriptor, either directly or via kobject_put.
Free sd_lkstats inside the kobject release function: that way,
gfs2_put_super will no longer leak sd_lkstats.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398

Based on 1 normalized pattern(s):

this copyrighted material is made available to anyone wishing to use
modify copy or redistribute it subject to the terms and conditions
of the gnu general public license version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 44 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.653000175@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

GFS2: update freeze code to use freeze/thaw_super on all nodes

The current gfs2 freezing code is considerably more complicated than it
should be because it doesn't use the vfs freezing code on any node except
the one that begins the freeze. This is because it needs to acquire a
cluster glock before calling the vfs code to prevent a deadlock, and
without the new freeze_super and thaw_super hooks, that was impossible. To
deal with the issue, gfs2 had to do some hacky locking tricks to make sure
that a frozen node couldn't be holding on a lock it needed to do the
unfreeze ioctl.

This patch makes use of the new hooks to simply the gfs2 locking code. Now,
all the nodes in the cluster freeze and thaw in exactly the same way. Every
node in the cluster caches the freeze glock in the shared state. The new
freeze_super hook allows the freezing node to grab this freeze glock in
the exclusive state without first calling the vfs freeze_super function.
All the nodes in the cluster see this lock change, and call the vfs
freeze_super function. The vfs locking code guarantees that the nodes can't
get stuck holding the glocks necessary to unfreeze the system. To
unfreeze, the freezing node uses the new thaw_super hook to drop the freeze
glock. Again, all the nodes notice this, reacquire the glock in shared mode
and call the vfs thaw_super function.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Clean up freeze code

The freeze code has not been looked at a lot recently. Upstream has
moved on, and this is an attempt to catch us back up again. There
is a vfs level interface for the freeze code which can be called
from our (obsolete, but kept for backward compatibility purposes)
sysfs freeze interface. This means freezing this way vs. doing it
from the ioctl should now work in identical fashion.

As a result of this, the freeze function is only called once
and we can drop our own special purpose code for counting the
number of freezes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

gfs: constify xattr_handler

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

GFS2: Alter arguments of gfs2_quota/statfs_sync

These two functions are altered so that gfs2_quota_sync may
in future be called directly from the VFS. The GFS2 superblock
changes to a VFS super block and there is an addition of an int
argument which is currently ignored.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix -o meta mounts for subsequent mounts (i.e. all but the first one)

We have a long term plan to use the "-o meta" flag to GFS2 mounts to
access the alternate root which is used to store metadata for a GFS2
filesystem. This will allow us to eventually remove support for the
gfs2meta filesystem type (which is in any case just a "front end" to
the gfs2 filesystem type with the meta/master root).

Currently the "-o meta" option is only taken into account on the
initial mount of the filesystem. Subsequent mounts of the same
filesystem (i.e. on the same device) result in basically the same
as bind mounting the root of the original mount.

This patch changes that by using what is more or less a copy
of get_sb_bdev() and extending it so that it will take into
account the alternate root in all cases. The main difference
is that we have to parse the mount options a bit earlier. We can
then use them to select the appropriate root towards the end of
the function.

In addition this also fixes a bug where it was possible (but certainly
not desirable) to set different ro/rw options for the meta root
when mounted via the gfs2meta fs compared with the original mount.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>

GFS2: Clean up of extended attribute support

This has been on my list for some time. We need to change the way
in which we handle extended attributes to allow faster file creation
times (by reducing the number of transactions required) and the
extended attribute code is the main obstacle to this.

In addition to that, the VFS provides a way to demultiplex the xattr
calls which we ought to be using, rather than rolling our own. This
patch changes the GFS2 code to use that VFS feature and as a result
the code shrinks by a couple of hundred lines or so, and becomes
easier to read.

I'm planning on doing further clean up work in this area, but this
patch is a good start. The cleaned up code also uses the more usual
"xattr" shorthand, I plan to eliminate the use of "eattr" eventually
and in the mean time it serves as a flag as to which bits of the code
have been updated.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add online uevent to GFS2

We already have an offline uevent (used when a withdraw occurs)
but no online uevent. This adds an online uevent so that userspace
will be able to detect a successful mount by means other than
not receiving a remove event after the add & recovery (change)
uevents.

It has also been added to the remount path as well - we can't use
a change uevent there as older GFS2 userspace acts on change uevents
according to the state that it thinks the fs is in, so we can't
easily add any new ones.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: keep statfs info in sync on grows

GFS2 wasn't syncing its statfs info on grows. This causes a problem
when you grow the filesystem on multiple nodes. GFS2 would calculate
the new space based on the resource groups (which are always current),
and then assume that the filesystem had grown the from the existing
statfs size. If you grew the filesystem on two different nodes in a
short time, the second node wouldn't see the statfs size change from the
first node, and would assume that it was grown by a larger amount than
it was. When all these changes were synced out, the total fileystem
size would be incorrect (the first grow would be counted twice).

This patch syncs makes GFS2 read in the statfs changes from disk before
a grow, and write them out after the grow, while the master statfs inode
is locked.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

constify dentry_operations: GFS2

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

GFS2: Fix remount argument parsing

The following patch fixes an issue relating to remount and argument
parsing. After this fix is applied, remount becomes atomic in that
it either succeeds changing the mount to the new state, or it fails
and leaves it in the old state. Previously it was possible for the
parsing of options to fail part way though and for the fs to be left
in a state where some of the new arguments had been applied, but some
had not.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

Revert "GFS2: Fix use-after-free bug on umount"

This reverts commit 78802499912f1ba31ce83a94c55b5a980f250a43.

The original patch is causing problems in relation to order of
operations at umount in relation to jdata files. I need to fix
this a different way.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix use-after-free bug on umount

There was a use-after-free with the GFS2 super block during
umount. This patch moves almost all of the umount code from
->put_super into ->kill_sb, the only bit that cannot be moved
being the glock hash clearing which has to remain as ->put_super
due to umount ordering requirements. As a result its now obvious
that the kfree is the final operation, whereas before it was
hidden in ->put_super.

Also gfs2_jindex_free is then only referenced from a single file
so thats moved and marked static too.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Move four functions from super.c

The functions which are being moved can all be marked
static in their new locations, since they only have
a single caller each. Their new locations are more
logical than before and some of the functions are
small enough that the compiler might well inline them.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix bug in gfs2_lock_fs_check_clean()

gfs2_lock_fs_check_clean() should not be calling gfs2_jindex_hold()
since it doesn't work like rindex hold, despite the comment. That
allows gfs2_jindex_hold() to be moved into ops_fstype.c where it
can be made static.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Rationalise header files

Move the contents of some headers which contained very
little into more sensible places, and remove the original
header files. This should make it easier to find things.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix metafs mounts

This patch is intended to fix the issues reported in bz #457798. Instead
of having the metafs as a separate filesystem, it becomes a second root
of gfs2. As a result it will appear as type gfs2 in /proc/mounts, but it
is still possible (for backwards compatibility purposes) to mount it as
type gfs2meta. A new mount flag "meta" is introduced so that its possible
to tell the two cases apart in /proc/mounts.

As a result it becomes possible to mount type gfs2 with -o meta and
get the same result as mounting type gfs2meta. So it is possible to
mount just the metafs on its own. Currently if you do this, its then
impossible to mount the "normal" root of the gfs2 filesystem without
first unmounting the metafs root. I'm not sure if thats a feature or
a bug :-)

Either way, this is a great improvement on the previous scheme and I've
verified that it works ok with bind mounts on both the "normal" root
and the metafs root in various combinations.

There were also a bunch of functions in super.c which didn't belong there,
so this moves them into ops_fstype.c where they can be static. Hopefully
the mount/umount sequence is now more obvious as a result.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>

[GFS2] Remove lm.[ch] and distribute content

The functions in lm.c were just wrappers which were mostly
only used in one other file. By moving the functions to
the files where they are being used, they can be marked
static and also this will usually result in them being inlined
since they are often only used from one point in the code.

A couple of really trivial functions have been inlined by hand
into the function which called them as it makes the code clearer
to do that.

We also gain from one fewer function call in the glock lock and
unlock paths.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Fix sign problem in quota/statfs and cleanup _host structures

This patch fixes some sign issues which were accidentally introduced
into the quota & statfs code during the endianess annotation process.
Also included is a general clean up which moves all of the _host
structures out of gfs2_ondisk.h (where they should not have been to
start with) and into the places where they are actually used (often only
one place). Also those _host structures which are not required any more
are removed entirely (which is the eventual plan for all of them).

The conversion routines from ondisk.c are also moved into the places
where they are actually used, which for almost every one, was just one
single place, so all those are now static functions. This also cleans up
the end of gfs2_ondisk.h which no longer needs the #ifdef __KERNEL__.

The net result is a reduction of about 100 lines of code, many functions
now marked static plus the bug fixes as mentioned above. For good
measure I ran the code through sparse after making these changes to
check that there are no warnings generated.

This fixes Red Hat bz #239686

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] split and annotate gfs2_statfs_change

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] split gfs2_sb

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Remove duplicate sb reading code

For some reason we had two different sets of code for reading in the
superblock. This removes one of them in favour of the other. Also we
don't need the temporary buffer for the sb since we already have one
in the gfs2 sb itself.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Make headers compile on their own

As per Jan Engelhardt's comments, this should make all the headers
compile on their own by including and/or declaring structures
early.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Change all types to uX style

This makes all fixed size types have consistent names.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Update copyright, tidy up incore.h

As per comments from Jan Engelhardt <jengelh@linux01.gwdg.de> this
updates the copyright message to say "version" in full rather than
"v.2". Also incore.h has been updated to remove forward structure
declarations which are not required.

The gfs2_quota_lvb structure has now had endianess annotations added
to it. Also quota.c has been updated so that we now store the
lvb data locally in endian independant format to avoid needing
a structure in host endianess too. As a result the endianess
conversions are done as required at various points and thus the
conversion routines in lvb.[ch] are no longer required. I've
moved the one remaining constant in lvb.h thats used into lm.h
and removed the unused lvb.[ch].

I have not changed the HIF_ constants. That is left to a later patch
which I hope will unify the gh_flags and gh_iflags fields of the
struct gfs2_holder.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Update copyright date to 2006

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] [-mm patch] fs/gfs2/: possible cleanups

This patch contains the following possible cleanups:
- make needlessly global code static
- #if 0 unused functions
- remove the following global function that was both unused and
unimplemented:
- super.c: gfs2_do_upgrade()

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Tidy up mount code.

We no longer lookup ".gfs2_admin" in the root directory in order to
find it, but instead use the inode number given in the superblock.
Both the root directory and the admin directory are now looked up using
the same routine, so the redundant code is removed.

Also, there is no longer a reference to the root inode in the
GFS2 super block. When required this can be retreived via
sb->s_root->d_inode instead.

Assuming that we introduce a metadata filesystem type for GFS, then
this is a first step towards that goal.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] The core of GFS2

This patch contains all the core files for GFS2.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>