I discovered that we had a list onto which every lock_dlm
lock was being put. Its only function was to discover whether
we'd got any locks left after umount. Since there was already
a counter for that purpose as well, I removed the list. The
saving is sizeof(struct list_head) per glock - well worth
having.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This looks like a lot of change, but in fact its not. Mostly its
things moving from one file to another. The change is just that
instead of queuing lock completions and callbacks from the DLM
we now pass them directly to GFS2.
This gives us a net loss of two list heads per glock (a fair
saving in memory) plus a reduction in the latency of delivering
the messages to GFS2, plus we now have one thread fewer as well.
There was a bug where callbacks and completions could be delivered
in the wrong order due to this unnecessary queuing which is fixed
by this patch.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
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>
There are several places where GFP_KERNEL allocations happen under a glock,
which will result in hangs if we're under memory pressure and go to re-enter the
fs in order to flush stuff out. This patch changes the culprits to GFS_NOFS to
keep this problem from happening. Thank you,
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
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>
This patch removes the completion (which is rather large) from struct
gdlm_lock in favour of using the wait_on_bit() functions. We don't need
to add any extra fields to the structure to do this, so we save 32 bytes
(on x86_64) per structure. This adds up to quite a lot when we may
potentially have millions of these lock structures,
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: David Teigland <teigland@redhat.com>
We always want to see the details of the error returned to gfs, but
log_debug is often turned off, so use log_error (printk).
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
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>
As requested by Jan Engelhardt, this removes the typedefs in the
locking module interface and replaces them with void *. Also
since we are changing the interface, I've added a few consts
as well.
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This code is no longer used for anything and can be removed
from the locking modules. The sync_lvb function is not required
as this happens automatically with the current locking system.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
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>
Typo causes the error value from the wrong lock to be checked.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
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>
All printk calls now have KERN_ set where required and a couple of
kmalloc(), memset(.., 0, ...) calls changed to kzalloc().
This is in response to comments from:
Pekka Enberg <penberg@cs.helsinki.fi> and
Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This is the second of two patches removing support for range
locks from the DLM
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This brings the lock modules uptodate and removes the stray
.mod.c file which accidently got included in the last check in.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch contains the pluggable locking modules
for GFS2.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
