The attached patch resolves bz 228540.  This adds the capability
for gfs2 to dump gfs2 locks through the debugfs file system.
This used to exist in gfs1 as "gfs_tool lockdump" but it's missing from
gfs2 because all the ioctls were stripped out.  Please see the bugzilla
for more history about the fix.  This patch is also attached to the bugzilla
record.

The patch is against Steve Whitehouse's latest nmw git tree kernel
(2.6.21-rc1) and has been tested on system trin-10.
Signed-off-by: NRobert Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The following removes an incorrect assertion from the GFS2 glops code. This
fixes Red Hat bz 229873. Thanks to Abhijith Das for testing the patch
and confirming the fix.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>

fs/gfs2/glock.c:2198: error: 'THIS_MODULE' undeclared here (not in a function)

Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

The ->go_drop_bh function is never used, so this removes it and the single
caller,
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Remove an unused variable.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The following patch fixes Red Hat bz 229831. Without this patch its
possible for the wrong inode to be returned in certain cases. It is a
pretty unusual event, so that its taken some time to track down. Thanks
and due to Josef Whiter who did a lot of the testing required to thrack
this down and fix it.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The below patch fixes a problem where we were not flushing rgrps
correctly. It only occurred in the specific case that a callback was
received for an rgrp which was dirty and when a journal log flush had
not already resulted in the rgrp being flushed anyway. This fixes Red
Hat bz 230143,
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

ok, the following is the minimum changes to get NFSD going before we
settle down this issue .. would appreciate this in the tree so other NFS
related works can get done in parallel.
Signed-off-by: NS. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This fixes a problem I encountered while running bonnie++.  When you have one
thread that opens a file and starts to write to it, and then another thread that
tries to open and write to the same file, the second thread will loop forever
trying to grab the inode lock for that inode.  Basically we come in through
generic_buffered_file_write, which calls gfs2_prepare_write, which then attempts
to grab the glock.  Because we don't own the lock, gfs2_prepare_write gets
GLR_TRYFAILED, which returns AOP_TRUNCATED_PAGE to generic_buffered_file_write.
At this point generic_buffered_file_write loops around again and immediately
retries the prepare_write.  This means that the second process never gets off of
the processor in order to allow the process that holds the lock to finish its
work and let go of the lock.  This patch makes gfs2_glock_nq schedule() if it
gets back a GLR_TRYFAILED, which resolves this problem.
Signed-off-by: NJosef Whiter <jwhiter@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

File handle checking error found in '07 NFS connectathon. The fh_type
and fh_len are not necessarily identical. Some of the client machines
could fail mount with stale filehandle without this patch.
Signed-off-by: NS. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Patch for the 2.6.20 stable tree that adds a missing newline to one of
the printk messages in fs/gfs2/ops_fstype.c.
Signed-off-by: NRichard Fearn <richardfearn@gmail.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch fixes a locking mistake in the quota code, we do a mutex_lock instead
of a mutex_unlock.
Signed-off-by: NJosef Whiter <jwhiter@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch is inspired by Arjan's "Patch series to mark struct
file_operations and struct inode_operations const".

Compile tested with gcc & sparse.
Signed-off-by: NJosef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many struct inode_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>

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>

Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
corresponding "kmem_cache_zalloc()" call.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Roland McGrath <roland@redhat.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On Mon, Jan 29, 2007 at 08:45:28PM -0800, Andrew Morton wrote:
>...
> Changes since 2.6.20-rc6-mm2:
>...
>  git-gfs2-nmw.patch
>...
>  git trees
>...

This patch makes the needlessly global gfs2_writepages() static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

When the try lock of the glock failed in prepare_write we were
incorrectly exiting this function with the page still locked.
This was resulting in further I/O to this page hanging.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Glock assertion failure found in '07 NFS connectathon. One of the NFSDs
is doing a "readdirplus" procedure call. It passes the logic into
gfs2_readdir() where it obtains its directory inode glock. This is then
followed by filehandle construction that invokes lookup code. It hits
the assertion failure while trying to obtain the inode glock again
inside gfs2_drevalidate().

This patch bypasses the recursive glock call if caller already holds the
lock.
Signed-off-by: NS. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Indent help text as expected.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Move the glock acquisition to outside of the transactions.

Lock odering must be preserved in order to prevent ABBA
deadlocks. The current gfs2_change_nlink code would tries
to grab the glock after having started a transaction and thus is holding
the log lock. This is inconsistent with other code paths in
gfs that grab the resource group glock prior to staring
a tranactions.

One problem with this fix is that the resource group
lock is always grabbed now even if the inode still has
ref count and can not be marked for unlink.
Signed-off-by: NRussell Cattelan <cattelan@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Dave Teigland fixed this bug a while back, but I managed to mistakenly
remove the semaphore during later development. It is required to avoid
the list of inodes changing during an invalidate_inodes call. I have
made it an rwsem since the read side will be taken frequently during
normal filesystem operation. The write site will only happen during
umount of the file system.

Also the bug only triggers when using the DLM lock manager and only then
under certain conditions as its timing related.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
Cc: David Teigland <teigland@redhat.com>

Whoops, quilt user error, missed this one in the previous patch.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

On Sun, Jan 28, 2007 at 11:08:18AM +0100, Jiri Slaby wrote:
> Andrew Morton napsal(a):
> >Temporarily at
> >
> >	http://userweb.kernel.org/~akpm/2.6.20-rc6-mm1/
>
> Unable to select IPV6. Menuconfig doesn't offer it when INET is selected.
> When it's not it appears in the menu, but after state change it gets away.
> The same behaviour in xconfig, gconfig.
>
> $ mkdir ../a/tst
> $ make O=../a/tst menuconfig
>   HOSTCC  scripts/basic/fixdep
> [...]
>   HOSTLD  scripts/kconfig/mconf
> scripts/kconfig/mconf arch/i386/Kconfig
> Warning! Found recursive dependency: INET GFS2_FS_LOCKING_DLM SYSFS
> OCFS2_FS INET
>
> Maybe this is the problem?

Yes, patch below.

> regards,

cu
Adrian

<--  snip  -->

This patch fixes a circular dependency by letting GFS2_FS_LOCKING_DLM
and DLM depend on instead of select SYSFS.

Since SYSFS depends on EMBEDDED this change shouldn't cause any problems
for users.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

With CONFIG_DLM=m, CONFIG_PROC_FS=n, and CONFIG_SYSFS=n, kernel build
fails with:

WARNING: "kernel_subsys" [fs/gfs2/locking/dlm/lock_dlm.ko] undefined!
WARNING: "kernel_subsys" [fs/dlm/dlm.ko] undefined!
WARNING: "kernel_subsys" [fs/configfs/configfs.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

Since fs/dlm/lockspace.c and fs/gfs2/locking/dlm/sysfs.c use
kernel_subsys, they should either DEPEND on it or SELECT it.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

We want to be able to change or disable the default drop_count (number at
which the dlm asks gfs to limit the the number of locks it's holding).
Add it to the collection of sysfs tunables for an fs.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Increase the number of locks at which point the dlm begins asking gfs to
reduce its lock usage.  The default value is largely arbitrary, but the
current value of 50,000 ends up limiting performance unnecessarily for too
many users.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The patch below appears to fix the list corruption that we are seeing on
occasion. Although the transaction structure is private to a single
thread, when the queued structures are dismantled during an in-core
commit, its possible for a different thread to be trying to add the same
structure to another, new, transaction at the same time.

To avoid this, this patch takes the log spinlock during this operation.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

In certain cases, its possible for NFS to call the lookup code while
holding the glock (when doing a readdirplus operation) so we need to
check for that and not try and lock the glock twice. This also fixes a
typo in a previous NFS related GFS2 patch.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This is a one letter typo fix in glock.c, spotted by Rob Kenna.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

I was looking something else up and came across this...

I don't honestly have a good reason to change it other than to make it
like every other Linux filesystem in this regard.  ;-)  It doesn't
functionally change anything, but makes some lines shorter. :)

I'm also curious; why does gfs2 have 64-bits of on-disk timestamps, but
not in timespec_t format, and only stores second resolutions?  Seems like
you're halfway to sub-second resolutions already.

I suppose if that gets implemented then all of the below should
instead be CURRENT_TIME not CURRENT_TIME_SEC.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This one liner got missed from the previous patch.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This function is not longer required since we do not do recursive
locking in the glock layer. As a result all its callers can be
replaceed with list_empty() calls.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch doesn't make any changes to the ordering of the various
operations related to glocking, but it does tidy up the calls to the
glops.c functions to make the structure more obvious.

The two functions: gfs2_glock_xmote_th() and gfs2_glock_drop_th() can be
made static within glock.c since they are called by every set of glock
operations. The xmote_th and drop_th glock operations are then made
conditional upon those two routines existing and called from the
previously mentioned functions in glock.c respectively.

Also it can be seen that the go_sync operation isn't needed since it can
easily be replaced by calls to xmote_bh and drop_bh respectively. This
results in no longer (confusingly) calling back into routines in glock.c
from glops.c and also reducing the glock operations by one member.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Here is a patch for GFS2 to remove the local exclusive flag. In
the places it was used, mutex's are always held earlier in the
call path, so it appears redundant in the LM_ST_SHARED case.

Also, the GFS2 holders were setting local exclusive in any case where
the requested lock was LM_ST_EXCLUSIVE. So the other places in the glock
code where the flag was tested have been replaced with tests for the
lock state being LM_ST_EXCLUSIVE in order to ensure the logic is the
same as before (i.e. LM_ST_EXCLUSIVE is always locally exclusive as well
as globally exclusive).
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This is never used, so we might as well remove it.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

The "greedy" code was an attempt to retain glocks for a minimum length
of time when they relate to mmap()ed files. The current implementation
of this feature is not, however, ideal in that it required allocating
memory in order to do this and its overly complicated.

It also misses the mark by ignoring the other I/O operations which are
just as likely to suffer from the same problem. So the plan is to remove
this now and then add the functionality back as part of the glock state
machine at a later date (and thus take into account all the possible
users of this feature)
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Here is something I spotted (while looking for something entirely
different) the other day.

Rather than using a completion in each and every struct gfs2_holder,
this removes it in favour of hashed wait queues, thus saving a
considerable amount of memory both on the stack (where a number of
gfs2_holder structures are allocated) and in particular in the
gfs2_inode which has 8 gfs2_holder structures embedded within it.

As a result on x86_64 the gfs2_inode shrinks from 2488 bytes to
1912 bytes, a saving of 576 bytes per inode (no thats not a typo!).
In actual practice we get a much better result than that since
now that a gfs2_inode is under the 2048 byte barrier, we get two
per 4k slab page effectively halving the amount of memory required
to store gfs2_inodes.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This removes an unused sysfs tunable parameter.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>