Commit Graph

119 Commits

Author SHA1 Message Date
Steven Whitehouse 719ee34467 GFS2: high time to take some time over atime
Until now, we've used the same scheme as GFS1 for atime. This has failed
since atime is a per vfsmnt flag, not a per fs flag and as such the
"noatime" flag was not getting passed down to the filesystems. This
patch removes all the "special casing" around atime updates and we
simply use the VFS's atime code.

The net result is that GFS2 will now support all the same atime related
mount options of any other filesystem on a per-vfsmnt basis. We do lose
the "lazy atime" updates, but we gain "relatime". We could add lazy
atime to the VFS at a later date, if there is a requirement for that
variant still - I suspect relatime will be enough.

Also we lose about 100 lines of code after this patch has been applied,
and I have a suspicion that it will speed things up a bit, even when
atime is "on". So it seems like a nice clean up as well.

From a user perspective, everything stays the same except the loss of
the per-fs atime quantum tweekable (ought to be per-vfsmnt at the very
least, and to be honest I don't think anybody ever used it) and that a
number of options which were ignored before now work correctly.

Please let me know if you've got any comments. I'm pushing this out
early so that you can all see what my plans are.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-09-18 13:53:59 +01:00
Steven Whitehouse dff5257473 GFS2: Fix race relating to glock min-hold time
In the case that a request for a glock arrives right after the
grant reply has arrived, it sometimes means that the gl_tstamp
field hasn't been updated recently enough. The net result is that
the min-hold time for the glock is ignored. If this happens
often enough, it leads to poor performance.

This patch adds an additional test, so that if the reply pending
bit is set on a glock, then it will select the maximum length of
time for the min-hold time, rather than looking at gl_tstamp.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-09-05 14:18:02 +01:00
Steven Whitehouse c1e817d03a GFS2: Fix debugfs glock file iterator
Due to an incorrect iterator, some glocks were being missed from the
glock dumps obtained via debugfs. This patch fixes the problem and
ensures that we don't miss any glocks in future.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-08-13 09:59:10 +01:00
Steven Whitehouse 209806aba9 [GFS2] Allow local DF locks when holding a cached EX glock
We already allow local SH locks while we hold a cached EX glock, so here
we allow DF locks as well. This works only because we rely on the VFS's
invalidation for locally cached data, and because if we hold an EX lock,
then we know that no other node can be caching data relating to this
file.

It dramatically speeds up initial writes to O_DIRECT files since we fall
back to buffered I/O for this and would otherwise bounce between DF and
EX modes on each and every write call. The lessons to be learned from
that are to ensure that (for the time being anyway) O_DIRECT files are
preallocated and that they are written to using reasonably large I/O
sizes. Even so this change fixes that corner case nicely

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-07-07 10:07:28 +01:00
Steven Whitehouse 265d529cef [GFS2] Fix delayed demote race
There is a race in the delayed demote code where it does the wrong thing
if a demotion to UN has occurred for other reasons before the delay has
expired. This patch adds an assert to catch that condition as well as
fixing the root cause by adding an additional check for the UN state.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
2008-07-07 10:02:36 +01:00
Steven Whitehouse 1bdad60633 [GFS2] Remove remote lock dropping code
There are several reasons why this is undesirable:

 1. It never happens during normal operation anyway
 2. If it does happen it causes performance to be very, very poor
 3. It isn't likely to solve the original problem (memory shortage
    on remote DLM node) it was supposed to solve
 4. It uses a bunch of arbitrary constants which are unlikely to be
    correct for any particular situation and for which the tuning seems
    to be a black art.
 5. In an N node cluster, only 1/N of the dropped locked will actually
    contribute to solving the problem on average.

So all in all we are better off without it. This also makes merging
the lock_dlm module into GFS2 a bit easier.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-06-27 09:39:44 +01:00
Steven Whitehouse 048bca2237 [GFS2] No lock_nolock
This patch merges the lock_nolock module into GFS2 itself. As well as removing
some of the overhead of the module, it also means that its now impossible to
build GFS2 without a lock module (which would be a pointless thing to do
anyway).

We also plan to merge lock_dlm into GFS2 in the future, but that is a more
tricky task, and will therefore be a separate patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: David Teigland <teigland@redhat.com>
2008-06-27 09:39:28 +01:00
Steven Whitehouse 6802e3400f [GFS2] Clean up the glock core
This patch implements a number of cleanups to the core of the
GFS2 glock code. As a result a lot of code is removed. It looks
like a really big change, but actually a large part of this patch
is either removing or moving existing code.

There are some new bits too though, such as the new run_queue()
function which is considerably streamlined. Highlights of this
patch include:

 o Fixes a cluster coherency bug during SH -> EX lock conversions
 o Removes the "glmutex" code in favour of a single bit lock
 o Removes the ->go_xmote_bh() for inodes since it was duplicating
   ->go_lock()
 o We now only use the ->lm_lock() function for both locks and
   unlocks (i.e. unlock is a lock with target mode LM_ST_UNLOCKED)
 o The fast path is considerably shortly, giving performance gains
   especially with lock_nolock
 o The glock_workqueue is now used for all the callbacks from the DLM
   which allows us to simplify the lock_dlm module (see following patch)
 o The way is now open to make further changes such as eliminating the two
   threads (gfs2_glockd and gfs2_scand) in favour of a more efficient
   scheme.

This patch has undergone extensive testing with various test suites
so it should be pretty stable by now.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
2008-06-27 09:39:22 +01:00
Benjamin Marzinski 58e9fee13e [GFS2] Invalidate cache at correct point
GFS2 wasn't invalidating its cache before it called into the lock manager
with a request that could potentially drop a lock.  This was leaving a
window where the lock could be actually be held by another node, but the
file's page cache would still appear valid, causing coherency problems.
This patch moves the cache invalidation to before the lock manager call
when dropping a lock. It also adds the option to the lock_dlm lock
manager to not use conversion mode deadlock avoidance, which, on a
conversion from shared to exclusive, could internally drop the lock, and
then reacquire in. GFS2 now asks lock_dlm to not do this.  Instead, GFS2
manually drops the lock and reacquires it.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:41:44 +01:00
Steven Whitehouse 840ca0ec70 [GFS2] Fix bug where we called drop_bh incorrectly
As a result of an earlier patch, drop_bh was being called in cases
when it shouldn't have been. Since we never have a gh in the drop
case and we always have a gh in the promote case, we can use that
extra information to tell which case has been seen.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
2008-03-31 10:41:01 +01:00
Bob Peterson cf45b752c9 [GFS2] Remove rgrp and glock version numbers
This patch further reduces GFS2's memory requirements by
eliminating the 64-bit version number fields in lieu of
a couple bits.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:29 +01:00
Steven Whitehouse da755fdb41 [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>
2008-03-31 10:40:26 +01:00
Bob Peterson ab0d756681 [GFS2] Eliminate gl_req_bh
This patch further reduces the memory needs of GFS2 by
eliminating the gl_req_bh variable from struct gfs2_glock.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:23 +01:00
Bob Peterson 29d38cd163 [GFS2] Get rid of gl_waiters2
This patch reduces memory by replacing the int variable
gl_waiters2 by a single bit in the gl_flags.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:13 +01:00
Adrian Bunk 048786f1e6 [GFS2] make gfs2_glock_hold() static
gfs2_glock_hold() can now become static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:02 +01:00
Bob Peterson ef8c441cb7 [GFS2] Only wake the reclaim daemon if we need to
This patch only wakes up the glock reclaim daemon if there is
actually something to be reclaimed.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31 10:40:00 +01:00
Pavel Emelyanov eccba06891 gfs2: make gfs2_glock.gl_owner_pid be a struct pid *
The gl_owner_pid field is used to get the lock owning task by its pid, so make
it in a proper manner, i.e.  by using the struct pid pointer and pid_task()
function.

The pid_task() becomes exported for the gfs2 module.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:06 -08:00
Pavel Emelyanov b1e058da50 gfs2: make gfs2_holder.gh_owner_pid be a struct pid *
The gl_owner_pid field is used to get the holder task by its pid and check
whether the current is a holder, so make it in a proper manner, i.e.  via the
struct pid * manipulations.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:06 -08:00
Bob Peterson 398bbe6832 [GFS2] Reorganize function gfs2_glmutex_lock
This patch optimizes the function gfs2_glmutex_lock.
The basic theory is: Why bother initializing a holder, setting up
wait bits and then waiting on them, if you know the glock can be
yours.  So the holder stuff is placed inside the if checking if the
glock is locked.  This one needs careful scrutiny because changing
anything to do with locking should strike terror into one's heart.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:13:52 +00:00
Fabio Massimo Di Nitto 1a2781cfa5 [GFS2] Fix runtime issue with UP kernels
The issue is indeed UP vs SMP and it is totally random.

spin_is_locked() is a bad assertion because there is no correct answer on UP.
on UP spin_is_locked() has to return either one value or another, always.

This means that in my setup I am lucky enough to trigger the issue and your you
are lucky enough not to.

the patch in attachment removes the bogus calls to BUG_ON and according to David
(in CC and thanks for the long explanation on the problem) we can rely upon
things like lockdep to find problem that might be trying to catch.

Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:06 +00:00
Steven Whitehouse 2bcd610d2f [GFS2] Don't add glocks to the journal
The only reason for adding glocks to the journal was to keep track
of which locks required a log flush prior to release. We add a
flag to the glock to allow this check to be made in a simpler way.

This reduces the size of a glock (by 12 bytes on i386, 24 on x86_64)
and means that we can avoid extra work during the journal flush.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:52 +00:00
Steven Whitehouse e589665eb9 [GFS2] Remove flags no longer required
The HIF_MUTEX and HIF_PROMOTE flags were set on the glock holders
depending upon which of the two waiters lists they were going to
be queued upon. They were then tested when the holders were taken
off the lists to ensure that the right type of holder was being
dequeued.

Since we are already using separate lists, there doesn't seem a
lot of point having these flags as well, and since setting them
and testing them is in the fast path for locking and unlocking
glock, this patch removes them.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:44 +00:00
Steven Whitehouse 3042a2ccd6 [GFS2] Reorder writeback for glock sync
Previously we were doing (write data, wait for data, write metadata, wait
for metadata). After this patch we so (write metadata, write data, wait for
data, wait for metadata) which should be more efficient.

Also I noticed that the drop_bh and xmote_bh functions were almost
identical. In fact the only difference was a single test, and that
test is such that in the drop_bh case, it would always evaluate to
the correct result. As such we can use the xmote_bh functions in
all the places where we were using the drop_bh function and remove
the drop_bh functions.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:42 +00:00
Steven Whitehouse c2932e03db [GFS2] Remove "reclaim limit"
This call to reclaim glocks is not needed, and in particular we don't want it
in the fast path for locking glocks. The limit was entirely arbitrary anyway
and we can't expect users to adjust things like this, the remaining code will
do the right thing on its own.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:37 +00:00
Wendy Cheng cc7e79b168 [GFS2] Handle multiple glock demote requests
Fix a race condition where multiple glock demote requests are sent to
a node back-to-back. This patch does a check inside handle_callback()
to see whether a demote request is in progress. If true, it sets a flag
to make sure run_queue() will loop again to handle the new request,
instead of erronously setting gl_demote_state to a different state.

Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:09 +00:00
Wendy Cheng 49e61f2ef6 [GFS2] Move inode deletion out of blocking_cb
Move inode deletion code out of blocking_cb handle_callback route to
avoid racy conditions that end up blocking lock_dlm1 thread. Fix
bugzilla 286821.

Signed-off-by: Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:56:17 +01:00
Abhijith Das b4c20166dc [GFS2] flocks from same process trip kernel BUG at fs/gfs2/glock.c:1118!
This patch adds a new flag to the gfs2_holder structure GL_FLOCK.
It is set on holders of glocks representing flocks. This flag is
checked in add_to_queue() and a process is permitted to queue more
than one holder onto a glock if it is set. This solves the issue
of a process not being able to do multiple flocks on the same file.
Through a single descriptor, a process can now promote and demote
flocks. Through multiple descriptors a process can now queue
multiple flocks on the same file. There's still the problem of
a process deadlocking itself (because gfs2 blocking locks are not
interruptible) by queueing incompatible deadlock.

Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:56:14 +01:00
Benjamin Marzinski c4f68a130f [GFS2] delay glock demote for a minimum hold time
When a lot of IO, with some distributed mmap IO, is run on a GFS2 filesystem in
a cluster, it will deadlock. The reason is that do_no_page() will repeatedly
call gfs2_sharewrite_nopage(), because each node keeps giving up the glock
too early, and is forced to call unmap_mapping_range(). This bumps the
mapping->truncate_count sequence count, forcing do_no_page() to retry. This
patch institutes a minimum glock hold time a tenth a second.  This insures
that even in heavy contention cases, the node has enough time to get some
useful work done before it gives up the glock.

A second issue is that when gfs2_glock_dq() is called from within a page fault
to demote a lock, and the associated page needs to be written out, it will
try to acqire a lock on it, but it has already been locked at a higher level.
This patch puts makes gfs2_glock_dq() use the work queue as well, to avoid this
issue. This is the same patch as Steve Whitehouse originally proposed to fix
this issue, execpt that gfs2_glock_dq() now grabs a reference to the glock
before it queues up the work on it.

Signed-off-by: Benjamin E. Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:55:48 +01:00
Abhijith Das a947e03356 [GFS2] Wendy's dump lockname in hex & fix glock dump
With this patch, gfs2 glockdump through the debugfs filesystem will only
dump glocks for the specified filesystem instead of all glocks. Also, to
aid debugging, the glock number is dumped in hex instead of decimal.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Abhijith Das <adas@redhat.com>
2007-10-10 08:55:41 +01:00
Steven Whitehouse 8fbbfd214c [GFS2] Reduce number of gfs2_scand processes to one
We only need a single gfs2_scand process rather than the one
per filesystem which we had previously. As a result the parameter
determining the frequency of gfs2_scand runs becomes a module
parameter rather than a mount parameter as it was before.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:55:08 +01:00
Denis Cheng 4ef290025c [GFS2] mark struct *_operations const
these struct *_operations are all method tables, thus should be const.

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:55:03 +01:00
Steven Whitehouse 7b08fc6201 [GFS2] Fix an oops in glock dumping
This fixes an oops which was occurring during glock dumping due to the
seq file code not taking a reference to the glock. Also this fixes a
memory leak which occurred in certain cases, in turn preventing the
filesystem from unmounting.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:54:49 +01:00
Jesper Juhl aa0481e58a [GFS2] Clean up duplicate includes in fs/gfs2/
This patch cleans up duplicate includes in
	fs/gfs2/

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:54:44 +01:00
Josef Whiter 26caee5bc6 [GFS2] Fix calculation of demote state
If a glock is in the exclusive state and a request for demote to
deferred has been received, then further requests for demote to
shared are being ignored. This patch fixes that by ensuring that
we demote to unlocked in that case.

Signed-off-by: Josef Whiter <jwhiter@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:54:42 +01:00
Steven Whitehouse 87124e581b [GFS2] Fix two races relating to glock callbacks
One of the races relates to referencing a variable while not holding
its protecting spinlock. The patch simply moves the test inside the
spin lock. The other races occurs when a demote to unlocked request
occurs during the time a demote to shared request is already running.
This of course only happens in the case that the lock was in the
exclusive mode to start with. The patch adds a check to see if another
demote request has occurred in the mean time and if it has, then it
performs a second demote.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:54:39 +01:00
Steven Whitehouse eaf5bd3cac [GFS2] Simplify multiple glock aquisition
There is a bug in the code which acquires multiple glocks where if the
initial out-of-order attempt fails part way though we can land up trying
to acquire the wrong number of glocks. This is part of the fix for red
hat bz #239737. The other part of the bz doesn't apply to upstream
kernels since it was fixed by:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=d3717bdf8f08a0e1039158c8bab2c24d20f492b6

Since the out-of-order code doesn't appear to add anything to the
performance of GFS2, this patch just removed it rather than trying to
fix it. It should be much easier to see whats going on here now. In
addition, we don't allocate any memory unless we are using a lot of
glocks (which is a relatively uncommon case).

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09 08:23:50 +01:00
Abhijith Das d93cfa9884 [GFS2] Fix deallocation issues
There were two issues during deallocation of unlinked inodes. The
first was relating to the use of a "try" lock which in the case of
the inode lock wasn't trying hard enough to deallocate in all
circumstances (now changed to a normal glock) and in the case of
the iopen lock didn't wait for the demotion of the shared lock before
attempting to get the exclusive lock, and thereby sometimes (timing dependent)
not completing the deallocation when it should have done.

The second issue related to the lack of a way to invalidate dcache entries
on remote nodes (now fixed by this patch) which meant that unlinks were
taking a long time to return disk space to the fs. By adding some code to
invalidate the dcache entries across the cluster for unlinked inodes, that
is now fixed.

This patch was written jointly by Abhijith Das and Steven Whitehouse.

Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09 08:23:36 +01:00
Steven Whitehouse dbb7cae2a3 [GFS2] Clean up inode number handling
This patch cleans up the inode number handling code. The main difference
is that instead of looking up the inodes using a struct gfs2_inum_host
we now use just the no_addr member of this structure. The tests relating
to no_formal_ino can then be done by the calling code. This has
advantages in that we want to do different things in different code
paths if the no_formal_ino doesn't match. In the NFS patch we want to
return -ESTALE, but in the ->lookup() path, its a bug in the fs if the
no_formal_ino doesn't match and thus we can withdraw in this case.

In order to later fix bz #201012, we need to be able to look up an inode
without knowing no_formal_ino, as the only information that is known to
us is the on-disk location of the inode in question.

This patch will also help us to fix bz #236099 at a later date by
cleaning up a lot of the code in that area.

There are no user visible changes as a result of this patch and there
are no changes to the on-disk format either.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09 08:22:24 +01:00
Robert Peterson cd81a4bac6 [GFS2] Addendum patch 2 for gfs2_grow
This addendum patch 2 corrects three things:

1. It fixes a stupid mistake in the previous addendum that broke gfs2.
   Ref: https://www.redhat.com/archives/cluster-devel/2007-May/msg00162.html
2. It fixes a problem that Dave Teigland pointed out regarding the
   external declarations in ops_address.h being in the wrong place.
3. It recasts a couple more %llu printks to (unsigned long long)
   as requested by Steve Whitehouse.

I would have loved to put this all in one revised patch, but there was
a rush to get some patches for RHEL5.	Therefore, the previous patches
were applied to the git tree "as is" and therefore, I'm posting another
addendum.  Sorry.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09 08:22:19 +01:00
Steven Whitehouse 37fde8ca6c [GFS2] Uncomment sprintf_symbol calling code
Now that the patch from -mm has gone upstream, we can uncomment the code
in GFS2 which uses sprintf_symbol.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Robert Peterson <rpeterso@redhat.com>
2007-05-01 09:51:39 +01:00
Robert Peterson 5f8820960c [GFS2] lockdump improvements
The patch below consists of the following changes (in code order):

1. I fixed a minor compiler warning regarding the printing of
   a kernel symbol address.
2. I implemented a suggestion from Dave Teigland that moves
   the debugfs information for gfs2 into a subdirectory so
   we can easily expand our use of debugfs in the future.
   The current code keeps the glock information in:
   /debug/gfs2/<fs>
   With the patch, the new code keeps the glock information in:
   /debug/gfs2/<fs>/glock
   That will allow us to create more debugfs files in the future.
3. This fixes a bug whereby a failed mount attempt causes the
   debugfs file to not be deleted.  Failed mount attempts should
   always clean up after themselves, including deleting the
   debugfs file and/or directory.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:11:33 +01:00
Robert Peterson 7a0079d9e3 [GFS2] bz 236008: Kernel gpf doing cat /debugfs/gfs2/xxx (lock dump)
This is for Bugzilla Bug 236008: Kernel gpf doing cat /debugfs/gfs2/xxx
(lock dump) seen at the "gfs2 summit".  This also fixes the bug that caused
garbage to be printed by the "initialized at" field.  I apologize for the
kludge, but that code will all be ripped out anyway when the official
sprint_symbol function becomes available in the Linux kernel.  I also
changed some formatting so that spaces are replaced by proper tabs.

Signed-off-by: Robert Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:11:28 +01:00
Robert Peterson 04b933f27b [GFS2] Red Hat bz 228540: owner references
In Testing the previously posted and accepted patch for
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=228540
I uncovered some gfs2 badness.  It turns out that the current
gfs2 code saves off a process pointer when glocks is taken
in both the glock and glock holder structures.  Those
structures will persist in memory long after the process has
ended; pointers to poisoned memory.

This problem isn't caused by the 228540 fix; the new capability
introduced by the fix just uncovered the problem.

I wrote this patch that avoids saving process pointers
and instead saves off the process pid.  Rather than
referencing the bad pointers, it now does process lookups.
There is special code that makes the output nicer for
printing holder information for processes that have ended.

This patch also adds a stub for the new "sprint_symbol"
function that exists in Andrew Morton's -mm patch set, but
won't go into the base kernel until 2.6.22, since it adds
functionality but doesn't fix a bug.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01 09:10:55 +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 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
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 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