Commit Graph

372 Commits

Author SHA1 Message Date
Benjamin Marzinski
172e045a7f [GFS2] flush the log if a transaction can't allocate space
This is a fix for bz #208514. When GFS2 frees up space, the freed blocks
aren't available for reuse until the resource group is successfully written
to the ondisk journal. So in rare cases, GFS2 operations will fail, saying
that the filesystem is out of space, when in reality, you are just waiting for
a log flush. For instance, on a 1Gig filesystem, if I continually write 10 Mb
to a file, and then truncate it, after a hundred interations, the write will
fail with -ENOSPC, even though the filesystem is just 1% full.

The attached patch calls a log flush in these cases.  I tested this patch
fairly heavily to check if there were any locking issues that I missed, and
it seems to work just fine. Also, this patch only does the log flush if
get_local_rgrp makes a complete loop of resource groups without skipping
any do to locking issues. The code would be slightly simpler if it just always
did the log flush after the first failed pass, and you could only ever have
to go through the loop twice, instead of up to three times. However, I guessed
that failing to find a rg simply do to locking issues would be common enough
to skip the log flush in that case, but I'm not certain that this is the right
way to go. Either way, I don't suppose this code will be hit all that often.

Signed-off-by: Benjamin E. Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:10:52 +01:00
Benjamin Marzinski
6883562588 [GFS2] Fix log entry list corruption
When glock_lo_add and rg_lo_add attempt to add an element to the log, they
check to see if has already been added before locking the log. If another
process adds that element to the log in this window between the check and
locking the log, the element will be added to the list twice. This causes
the log element list to become corrupted in such a way that the log element
can never be successfully removed from the list. This patch pulls the
list_empty() check inside the log lock, to remove this window.

Signed-off-by: Benjamin E. Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:10:50 +01:00
Steven Whitehouse
f35ac346bc [GFS2] Speed up lock_dlm's locking (move sprintf)
The following patch speeds up lock_dlm's locking by moving the sprintf
out from the lock acquisition path and into the lock creation path. This
reduces the amount of CPU time used in acquiring locks by a fair amount.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: David Teigland <teigland@redhat.com>
2007-05-01 09:10:47 +01:00
Steven Whitehouse
420d2a1028 [GFS2] Fix a bug on i386 due to evaluation order
Since gcc didn't evaluate the last two terms of the expression in
glock.c:1881 as a constant expression, it resulted in an error on
i386 due to the lack of a 64bit divide instruction. This adds some
brackets to fix the problem.

This was reported by Andrew Morton.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2007-05-01 09:10:42 +01:00
Steven Whitehouse
3b8249f617 [GFS2] Fix bz 224480 and cleanup glock demotion code
This patch prevents the printing of a warning message in cases where
the fs is functioning normally by handing off responsibility for
unlinked, but still open inodes, to another node for eventual deallocation.
Also, there is now an improved system for ensuring that such requests
to other nodes do not get lost. The callback on the iopen lock is
only ever called when i_nlink == 0 and when a node is unable to deallocate
it due to it still being in use on another node. When a node receives
the callback therefore, it knows that i_nlink must be zero, so we mark
it as such (in gfs2_drop_inode) in order that it will then attempt
deallocation of the inode itself.

As an additional benefit, queuing a demote request no longer requires
a memory allocation. This simplifies the code for dealing with gfs2_holders
as it removes one special case.

There are two new fields in struct gfs2_glock. gl_demote_state is the
state which the remote node has requested and gl_demote_time is the
time when the request came in. Both fields are only valid when the
GLF_DEMOTE flag is set in gl_flags.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:10:39 +01:00
Josef Whiter
1de9139092 [GFS2] Fix bz 231380, unlock page before dequeing glocks in gfs2_commit_write
If we are writing a file, and in the middle of writing the file
another node attempts to get a shared lock on that file (by doing a du for
example) the process doing the writing will hang waiting on lock_page.  The
reason for this is because when we have waiters on a exclusive glock, we will go
through and flush out all dirty pages associated with that inode and release the
lock.  The problem is that when we flush the dirty pages, we could hit a page
that we have locked durring the generic_file_buffered_write part of this
operation.  This patch unlocks the page before we go to dequeue the lock and
locks it immediatly afterwards, since generic_file_buffered_write needs the page
locked when the commit_write is completed.  This patch resolves the problem,
however if somebody sees a better way to do this please don't hesistate to yell.

Signed-off-by: Josef Whiter <jwhiter@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:10:37 +01:00
Josef Whiter
5c7342d894 [GFS2] fix bz 231369, gfs2 will oops if you specify an invalid mount option
If you specify an invalid mount option when trying to mount a gfs2 filesystem,
gfs2 will oops.  The attached patch resolves this problem.

Signed-off-by: Josef Whiter <jwhiter@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:10:32 +01:00
Robert Peterson
7c52b166c5 [GFS2] Add gfs2_tool lockdump support to gfs2 (bz 228540)
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: Robert Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:10:29 +01:00
Steven Whitehouse
c3f49bc209 [GFS2] Fix bz 229873, alternate test: assertion "!ip->i_inode.i_mapping->nrpages" failed
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: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>
2007-03-07 14:03:53 -05:00
akpm@linux-foundation.org
95d97b7dd7 [GFS2] build fix
fs/gfs2/glock.c:2198: error: 'THIS_MODULE' undeclared here (not in a function)

Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-03-07 14:03:25 -05:00
Steven Whitehouse
631c42e170 [GFS2] go_drop_bh is never used, so remove it
The ->go_drop_bh function is never used, so this removes it and the single
caller,

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 14:02:53 -05:00
Steven Whitehouse
04b159b132 [GFS2] Remove unused variable
Remove an unused variable.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 14:02:30 -05:00
Steven Whitehouse
1be3867955 [GFS2] Fix bz 229831, lookup returns wrong inode
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: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 14:01:53 -05:00
Steven Whitehouse
cad5b93927 [GFS2] Fix bz 230143, incorrect flushing of rgrps
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: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 14:00:14 -05:00
Wendy Cheng
fb0d3bce8e [GFS2] pass formal ino in do_filldir_main
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: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 13:58:45 -05:00
Josef Whiter
a13cbe3753 [GFS2] fix hangup when multiple processes are trying to write to the same file
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: Josef Whiter <jwhiter@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 13:58:02 -05:00
Wendy Cheng
a7d2b2bdc9 [GFS2] NFS filehandle check
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: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 13:57:34 -05:00
Richard Fearn
d5a6751b32 [GFS2] add newline to printk message
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: Richard Fearn <richardfearn@gmail.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 13:57:10 -05:00
Josef Whiter
2e95b6653b [GFS2] fix locking mistake
This patch fixes a locking mistake in the quota code, we do a mutex_lock instead
of a mutex_unlock.

Signed-off-by: Josef Whiter <jwhiter@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07 13:56:41 -05:00
Tim Schmielau
cd354f1ae7 [PATCH] remove many unneeded #includes of sched.h
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: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:54 -08:00
Josef 'Jeff' Sipek
ee9b6d61a2 [PATCH] Mark struct super_operations const
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: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:47 -08:00
Arjan van de Ven
92e1d5be91 [PATCH] mark struct inode_operations const 2
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: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:46 -08:00
Arjan van de Ven
00977a59b9 [PATCH] mark struct file_operations const 6
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: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00
Robert P. J. Day
c376222960 [PATCH] Transform kmem_cache_alloc()+memset(0) -> kmem_cache_zalloc().
Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
corresponding "kmem_cache_zalloc()" call.

Signed-off-by: Robert 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: Joel 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:27 -08:00
Adrian Bunk
a2cf822274 [GFS2] make gfs2_writepages() static
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: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-07 10:48:48 -05:00
Steven Whitehouse
2d72e7101c [GFS2] Unlock page on prepare_write try lock failure
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: Steven Whitehouse <swhiteho@redhat.com>
2007-02-07 10:25:59 -05:00
Wendy Cheng
549ae0ac3d [GFS2] nfsd readdirplus assertion failure
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: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-06 11:36:01 -05:00
Randy Dunlap
9beeb9f3c5 [DLM/GFS2] indent help text
Indent help text as expected.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:38:20 -05:00
Russell Cattelan
ddee76089c [GFS2] Fix unlink deadlocks
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: Russell Cattelan <cattelan@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:38:17 -05:00
Steven Whitehouse
61be084efc [GFS2] Put back semaphore to avoid umount problem
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: Steven Whitehouse <swhiteho@redhat.com>
Cc: David Teigland <teigland@redhat.com>
2007-02-05 13:38:14 -05:00
Eric Sandeen
bbb28ab759 [GFS2] more CURRENT_TIME_SEC
Whoops, quilt user error, missed this one in the previous patch.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:38:11 -05:00
Adrian Bunk
0011727785 [GFS2/DLM] fix GFS2 circular dependency
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: Adrian Bunk <bunk@stusta.de>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:38:08 -05:00
Randy Dunlap
67f55897ee [GFS2/DLM] use sysfs
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: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:38:05 -05:00
David Teigland
ee32e4f3d3 [GFS2] make lock_dlm drop_count tunable in sysfs
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: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:38:01 -05:00
David Teigland
2f708649ba [GFS2] increase default lock limit
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: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:59 -05:00
Steven Whitehouse
8bd9572769 [GFS2] Fix list corruption in lops.c
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: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:56 -05:00
Steven Whitehouse
d7c103d0bd [GFS2] Fix recursive locking attempt with NFS
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: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:53 -05:00
Steven Whitehouse
d043e1900c [GFS2] Fix typo in glock.c
This is a one letter typo fix in glock.c, spotted by Rob Kenna.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:41 -05:00
Eric Sandeen
ddfe062783 [GFS2] use CURRENT_TIME_SEC instead of get_seconds in gfs2
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: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:38 -05:00
Steven Whitehouse
90101c3186 [GFS2] Compile fix for glock.c
This one liner got missed from the previous patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:35 -05:00
Steven Whitehouse
12132933c4 [GFS2] Remove queue_empty() function
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: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:32 -05:00
Steven Whitehouse
b5d32bead1 [GFS2] Tidy up glops calls
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: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:26 -05:00
Steven Whitehouse
1c0f4872dc [GFS2] Remove local exclusive glock mode
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: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:20 -05:00
Steven Whitehouse
6bd9c8c2fb [GFS2] Remove unused go_callback operation
This is never used, so we might as well remove it.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:17 -05:00
Steven Whitehouse
e5dab552c8 [GFS2] Remove the "greedy" function from glock.[ch]
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: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:14 -05:00
Steven Whitehouse
fee852e374 [GFS2] Shrink gfs2_inode memory by half
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: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:11 -05:00
Steven Whitehouse
330005c2b2 [GFS2] Remove max_atomic_write tunable
This removes an unused sysfs tunable parameter.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:08 -05:00
Steven Whitehouse
3699e3a44b [GFS2] Clean up/speed up readdir
This removes the extra filldir callback which gfs2 was using to
enclose an attempt at readahead for inodes during readdir. The
code was too complicated and also hurts performance badly in the
case that the getdents64/readdir call isn't being followed by
stat() and it wasn't even getting it right all the time when it
was.

As a result, on my test box an "ls" of a directory containing 250000
files fell from about 7mins (freshly mounted, so nothing cached) to
between about 15 to 25 seconds. When the directory content was cached,
the time taken fell from about 3mins to about 4 or 5 seconds.

Interestingly in the cached case, running "ls -l" once reduced the time
taken for subsequent runs of "ls" to about 6 secs even without this
patch. Now it turns out that there was a special case of glocks being
used for prefetching the metadata, but because of the timeouts for these
locks (set to 10 secs) the metadata was being timed out before it was
being used and this the prefetch code was constantly trying to prefetch
the same data over and over.

Calling "ls -l" meant that the inodes were brought into memory and once
the inodes are cached, the glocks are not disposed of until the inodes
are pushed out of the cache, thus extending the lifetime of the glocks,
and thus bringing down the time for subsequent runs of "ls"
considerably.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:04 -05:00
Steven Whitehouse
a8d638e30e [GFS2] Add writepages for "data=writeback" mounts
It occurred to me that although a gfs2 specific writepages for ordered
writes and journaled data would be tricky, by hooking writepages only
for "data=writeback" mounts we could take advantage of not needing
buffer heads (we don't use them on the read side, nor have we for some
time) and create much larger I/Os for the block layer.

Using blktrace both before and after, its possible to see that for large
I/Os, most of the requests generated through writepages are now 1024
sectors after this patch is applied as opposed to 8 sectors before.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:37:01 -05:00
Adrian Bunk
03dc6a538e [GFS2] make gfs2_change_nlink_i() static
On Thu, Jan 11, 2007 at 10:26:27PM -0800, Andrew Morton wrote:
>...
> Changes since 2.6.20-rc3-mm1:
>...
>  git-gfs2-nmw.patch
>...
>  git trees
>...

This patch makes the needlessly globlal gfs2_change_nlink_i() static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:36:49 -05:00