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2009-05-22GFS2: Move gfs2_rmdiri into ops_inode.cSteven Whitehouse
Move gfs2_rmdiri() into ops_inode.c and make it static. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-22GFS2: Merge mount.c and ops_super.c into super.cSteven Whitehouse
mount.c only contained a single function, so is not really worth retaining on its own. All of the super related code is now either in super.c or ops_fstype.c Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-22GFS2: Clean up some file namesSteven Whitehouse
This patch renames the ops_*.c files which have no counterpart without the ops_ prefix in order to shorten the name and make it more readable. In addition, ops_address.h (which was very small) is moved into inode.h and inode.h is cleaned up by adding extern where required. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-21GFS2: Be more aggressive in reclaiming unlinked inodesSteven Whitehouse
This patch increases the frequency with which gfs2 looks for unlinked, but still allocated inodes. Its the equivalent operation to ext3's orphan list, but done with bitmaps in the resource groups. This also fixes a bug where a field in the rgrp was too small. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-21GFS2: Add a rgrp bitmap full flagSteven Whitehouse
During block allocation, it is useful to know if sections of disk are full on a finer grained basis than a single resource group. This can make a performance difference when resource groups have larger numbers of bitmap blocks, since we no longer have to search them all block by block in each individual bitmap. The full flag is set on a per-bitmap basis when it has been searched and found to have no free space. It is then skipped in subsequent searches until the flag is reset. The resetting occurs if we have to drop the glock on the resource group for any reason, or if we deallocate some blocks within that resource group and thus free up some space. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-20GFS2: Improve resource group error handlingSteven Whitehouse
This patch improves the error handling in the case where we discover that the summary information in the resource group doesn't match the bitmap information while in the process of allocating blocks. Originally this resulted in a kernel bug, but this patch changes that so that we return -EIO and print some messages explaining what went wrong, and how to fix it. We also remember locally not to try and allocate from the same rgrp again, so that a subsequent allocation in a different rgrp should succeed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-19GFS2: Don't warn when delete inode fails on ro filesystemSteven Whitehouse
If the filesystem is read-only, then we expect that delete inode will fail, so there is no need to warn about it. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-19GFS2: Umount recovery race fixSteven Whitehouse
This patch fixes a race condition where we can receive recovery requests part way through processing a umount. This was causing problems since the recovery thread had already gone away. Looking in more detail at the recovery code, it was really trying to implement a slight variation on a work queue, and that happens to align nicely with the recently introduced slow-work subsystem. As a result I've updated the code to use slow-work, rather than its own home grown variety of work queue. When using the wait_on_bit() function, I noticed that the wait function that was supplied as an argument was appearing in the WCHAN field, so I've updated the function names in order to produce more meaningful output. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-13GFS2: Remove a couple of unused sysfs entriesSteven Whitehouse
These two tunables are pointless and would never need to be changed anyway. There is also a race between them and umount as the deamons which they refer to might have gone away. The easiest way to fix the race is to remove the interface. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-13GFS2: Add commit= mount optionSteven Whitehouse
It has always been possible to adjust the gfs2 log commit interval, but only from the sysfs interface. This adds a mount option, commit=<nn>, which will be familar to ext3 users. The sysfs interface continues to be available as well, although this might be removed in the future. Also this patch cleans up some duplicated structures in the GFS2 sysfs code. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-13GFS2: Move journal live test at transaction startSteven Whitehouse
There seems little point grabbing the transaction glock only to have to release it again if the journal isn't live. This moves the test earlier to avoid grabbing the lock when we don't need it in the first place. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-12GFS2: Fix timestamps on writeAbhijith Das
This patch copies the timestamps from the vfs inode into gfs2 and syncs it to the disk inode during writes. Signed-off-by: Abhijith Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-11GFS2: Something nonlinear this way comes!Steven Whitehouse
For some reason GFS2 has been missing support for non-linear mappings. This patch fixes that, and also avoids taking any locks for mmap in the O_NOATIME case. In fact we don't actually need to take the lock here at all - just doing file_accessed() would be enough, but we have to take the lock eventually and this helps it hit disk (and thus be seen by other nodes) faster. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-11GFS2: Optimise writepage for metadataSteven Whitehouse
This adds a GFS2 specific writepage for metadata, rather than continuing to use the VFS function. As a result we now tag all our metadata I/O with the correct flag so that blktraces will now be less confusing. Also, the generic function was checking for a number of corner cases which cannot happen on the metadata address spaces so that this should be faster too. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-11GFS2: Update the rw flagsSteven Whitehouse
After Jens recent updates: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=a1f242524c3c1f5d40f1c9c343427e34d1aadd6e et al. this is a patch to bring gfs2 uptodate with the core code. Also I've managed to squash another call to ll_rw_block() along the way. There is still one part of the GFS2 I/O paths which are not correctly annotated and that is due to the sharing of the writeback code between the data and metadata address spaces. I would like to change that too, but this patch is still worth doing on its own, I think. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-05-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (22 commits) Fix the race between capifs remount and node creation Fix races around the access to ->s_options switch ufs directories to ufs_sync_file() Switch open_exec() and sys_uselib() to do_open_filp() Make open_exec() and sys_uselib() use may_open(), instead of duplicating its parts Reduce path_lookup() abuses Make checkpatch.pl shut up on fs/inode.c NULL noise in fs/super.c:kill_bdev_super() romfs: cleanup romfs_fs.h ROMFS: romfs_dev_read() error ignored fs: dcache fix LRU ordering ocfs2: Use nd_set_link(). Fix deadlock in ipathfs ->get_sb() Fix a leak in failure exit in 9p ->get_sb() Convert obvious places to deactivate_locked_super() New helper: deactivate_locked_super() reiserfs: remove privroot hiding in lookup reiserfs: dont associate security.* with xattr files reiserfs: fixup xattr_root caching Always lookup priv_root on reiserfs mount and keep it ...
2009-05-09Reduce path_lookup() abusesAl Viro
... use kern_path() where possible [folded a fix from rdd] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09GFS2: Fix glock ref counting bugSteven Whitehouse
Depending on the ordering of events as we go around the glock shrinker loop, it is possible to drop the ref count of a glock incorrectly. It doesn't happen very often. This patch corrects the got_ref variable, fixing the problem. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-23GFS2: Ensure that the inode goal block settings are updatedSteven Whitehouse
GFS2 has a goal block associated with each inode indicating the search start position for future block allocations (in fact there are two, but thats for backward compatibility with GFS1 as they are set to identical locations in GFS2). In some circumstances, depending on the ordering of updates to the inode it was possible for the goal block settings to not be updated on disk. This patch ensures that the goal block will always get updated, thus reducing the potential for searching the same (already allocated) blocks again when looking for free space during block allocation. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-23GFS2: Fix bug in block allocationSteven Whitehouse
The new bitfit algorithm was counting from the wrong end of 64 bit words in the bitfield. This fixes it by using __ffs64 instead of fls64 Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-20GFS2: Fix page_mkwrite() return codeSteven Whitehouse
This allows for the possibility of returning VM_FAULT_OOM as well as VM_FAULT_SIGBUS. This ensures that the correct action is taken. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-20GFS2: Clear dirty bit at end of inode glock syncSteven Whitehouse
The dirty bit can get set during the inode glock sync. Its too complicated to change that at the moment, so this is the quick fix - to clear the bit again at the end of the function. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixesLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes: GFS2: Use DEFINE_SPINLOCK GFS2: cleanup file_operations mess GFS2: Move umount flush rwsem GFS2: Fix symlink creation race GFS2: Make quotad's waiting interruptible
2009-04-15gfs2: Remove code handling bio_alloc failure with __GFP_WAITNikanth Karthikesan
Remove code handling bio_alloc failure with __GFP_WAIT. GFP_NOFS implies __GFP_WAIT. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15GFS2: Use DEFINE_SPINLOCKXu Gang
SPIN_LOCK_UNLOCKED is deprecated, use DEFINE_SPINLOCK instead. (as suggested in Documentation/spinlocks.txt) Signed-off-by: Xu Gang <xug@cn.fujitsu.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15GFS2: cleanup file_operations messChristoph Hellwig
Remove the weird pointer to file_operations mess and replace it with straight-forward defining of the lockinginstance names to the _nolock variants. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15GFS2: Move umount flush rwsemSteven Whitehouse
The rwsem, used only on umount, is in the wrong place in glock.c. This patch moves it up a bit so that it does not get called under a spinlock. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15GFS2: Fix symlink creation raceSteven Whitehouse
In certain cases symlinks can appear to have zero size if a lookup on the inode occurs within a certain (very short) time after the symlink has been created. The symlink is correctly created on disk but appears to have zero size when stat()ed. This patch closes the race and prevents incorrect sizes appearing. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-15GFS2: Make quotad's waiting interruptibleSteven Whitehouse
So we don't count its D state in the loadavg. Reported-by: Nathan Straz <nstraz@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-04-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: Remove two unneeded exports and make two symbols static in fs/mpage.c Cleanup after commit 585d3bc06f4ca57f975a5a1f698f65a45ea66225 Trim includes of fdtable.h Don't crap into descriptor table in binfmt_som Trim includes in binfmt_elf Don't mess with descriptor table in load_elf_binary() Get rid of indirect include of fs_struct.h New helper - current_umask() check_unsafe_exec() doesn't care about signal handlers sharing New locking/refcounting for fs_struct Take fs_struct handling to new file (fs/fs_struct.c) Get rid of bumping fs_struct refcount in pivot_root(2) Kill unsharing fs_struct in __set_personality()
2009-04-01mm: page_mkwrite change prototype to match faultNick Piggin
Change the page_mkwrite prototype to take a struct vm_fault, and return VM_FAULT_xxx flags. There should be no functional change. This makes it possible to return much more detailed error information to the VM (and also can provide more information eg. virtual_address to the driver, which might be important in some special cases). This is required for a subsequent fix. And will also make it easier to merge page_mkwrite() with fault() in future. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Cc: Felix Blyakher <felixb@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31New helper - current_umask()Al Viro
current->fs->umask is what most of fs_struct users are doing. Put that into a helper function. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits) fs: avoid I_NEW inodes Merge code for single and multiple-instance mounts Remove get_init_pts_sb() Move common mknod_ptmx() calls into caller Parse mount options just once and copy them to super block Unroll essentials of do_remount_sb() into devpts vfs: simple_set_mnt() should return void fs: move bdev code out of buffer.c constify dentry_operations: rest constify dentry_operations: configfs constify dentry_operations: sysfs constify dentry_operations: JFS constify dentry_operations: OCFS2 constify dentry_operations: GFS2 constify dentry_operations: FAT constify dentry_operations: FUSE constify dentry_operations: procfs constify dentry_operations: ecryptfs constify dentry_operations: CIFS constify dentry_operations: AFS ...
2009-03-27constify dentry_operations: GFS2Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-24GFS2: Fix freeze issueSteven Whitehouse
This removes some old code that was causing issues during filesystem freeze. Reported-by: Andrew Price <andy@andrewprice.me.uk> Tested-by: Andrew Price <andy@andrewprice.me.uk> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24Fix a minor bug in the previous patchSteven Whitehouse
The logic requires that we mark the glock dirty in page_mkwrite otherwise we might not flush correctly in the case that no allocation was required in the process of dirying the page. Also we need to set the shared write flag early for the same reason. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Clean up of glops.cSteven Whitehouse
This cleans up a number of bits of code mostly based in glops.c. A couple of simple functions have been merged into the callers to make it more obvious what is going on, the mysterious raising of i_writecount around the truncate_inode_pages() call has been removed. The meta_go_* operations have been renamed rgrp_go_* since that is the only lock type that they are used with. The unused argument of gfs2_read_sb has been removed. Also a bug has been fixed where a check for the rindex inode was in the wrong callback. More comments are added, and the debugging code is improved too. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Fix locking bug in failed shared to exclusive conversionBenjamin Marzinski
After calling out to the dlm, GFS2 sets the new state of a glock to gl_target in gdlm_ast(). However, gl_target is not always the lock state that was requested. If a conversion from shared to exclusive fails, finish_xmote() will call do_xmote() with LM_ST_UNLOCKED, instead of gl->gl_target, so that it can reacquire the lock in exlusive the next time around. In this case, setting the lock to gl_target in gdlm_ast() will make GFS2 think that it has the glock in exclusive mode, when really, it doesn't have the glock locked at all. This patch adds a new field to the gfs2_glock structure, gl_req, to track the mode that was requested. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Pagecache usage optimization on GFS2Hisashi Hifumi
I introduced "is_partially_uptodate" aops for GFS2. A page can have multiple buffers and even if a page is not uptodate, some buffers can be uptodate on pagesize != blocksize environment. This aops checks that all buffers which correspond to a part of a file that we want to read are uptodate. If so, we do not have to issue actual read IO to HDD even if a page is not uptodate because the portion we want to read are uptodate. "block_is_partially_uptodate" function is already used by ext2/3/4. With the following patch random read/write mixed workloads or random read after random write workloads can be optimized and we can get performance improvement. I did a performance test using the sysbench. #sysbench --num-threads=16 --max-requests=200000 --test=fileio --file-num=1 --file-block-size=8K --file-total-size=2G --file-test-mode=rndrw --file-fsync-freq=0 --file-rw-ratio=1 run -2.6.29-rc6 Test execution summary: total time: 202.6389s total number of events: 200000 total time taken by event execution: 2580.0480 per-request statistics: min: 0.0000s avg: 0.0129s max: 49.5852s approx. 95 percentile: 0.0462s -2.6.29-rc6-patched Test execution summary: total time: 177.8639s total number of events: 200000 total time taken by event execution: 2419.0199 per-request statistics: min: 0.0000s avg: 0.0121s max: 52.4306s approx. 95 percentile: 0.0444s arch: ia64 pagesize: 16k blocksize: 4k Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: fix sparse warning: Should it be static?Hannes Eder
Impact: Make symbol static. Fix this sparse warning: fs/gfs2/rgrp.c:188:5: warning: symbol 'gfs2_bitfit' was not declared. Should it be static? Signed-off-by: Hannes Eder <hannes@hanneseder.net> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: fix sparse warnings: constant is so big it is ...Hannes Eder
Fix this sparse warnings: fs/gfs2/rgrp.c:156:23: warning: constant 0xffffffffffffffff is so big it is unsigned long long fs/gfs2/rgrp.c:157:23: warning: constant 0xaaaaaaaaaaaaaaaa is so big it is unsigned long long fs/gfs2/rgrp.c:158:23: warning: constant 0x5555555555555555 is so big it is long long fs/gfs2/rgrp.c:194:20: warning: constant 0x5555555555555555 is so big it is long long fs/gfs2/rgrp.c:204:44: warning: constant 0x5555555555555555 is so big it is long long Signed-off-by: Hannes Eder <hannes@hanneseder.net> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Support quota/noquota mount argumentsSteven Whitehouse
This adds support for "quota" and "noquota" mount options in addition to the existing "quota=on/off/account" so that we are compatible with the names by which these options are more generally known. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Fix alignment issue and tidy gfs2_bitfitSteven Whitehouse
An alignment issue with the existing bitfit algorithm was reported on IA64. This patch attempts to fix that, and also to tidy up the code a bit. There is now more documentation about how this works and it has survived a number of different tests. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Add a "demote a glock" interface to sysfsSteven Whitehouse
This adds a sysfs file called demote_rq to GFS2's per filesystem directory. Its possible to use this file to demote arbitrary glocks in exactly the same way as if a request had come in from a remote node. This is intended for testing issues relating to caching of data under glocks. Despite that, the interface is generic enough to send requests to any type of glock, but be careful as its not always safe to send an arbitrary message to an arbitrary glock. For that reason and to prevent DoS, this interface is restricted to root only. The messages look like this: <type>:<glocknumber> <mode> Example: echo -n "2:13324 EX" >/sys/fs/gfs2/unity:myfs/demote_rq Which means "please demote inode glock (type 2) number 13324 so that I can get an EX (exclusive) lock". The lock modes are those which would normally be sent by a remote node in its callback so if you want to unlock a glock, you use EX, to demote to shared, use SH or PR (depending on whether you like GFS2 or DLM lock modes better!). If the glock doesn't exist, you'll get -ENOENT returned. If the arguments don't make sense, you'll get -EINVAL returned. The plan is that this interface will be used in combination with the blktrace patch which I recently posted for comments although it is, of course, still useful in its own right. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Expose UUID via sysfs/ueventSteven Whitehouse
Since we have a UUID, we ought to expose it to the user via sysfs and uevents. We already have the fs name in both of these places (a combination of the lock proto and lock table name) so if we add the UUID as well, we have a full set. For older filesystems (i.e. those created before mkfs.gfs2 was writing UUIDs by default) the sysfs file will appear zero length, and no UUID env var will be added to the uevents. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Support generation of discard requestsSteven Whitehouse
This patch allows GFS2 to generate discard requests for blocks which are no longer useful to the filesystem (i.e. those which have been freed as the result of an unlink operation). The requests are generated at the time which those blocks become available for reuse in the filesystem. In order to use this new feature, you have to specify the "discard" mount option. The code coalesces adjacent blocks into a single extent when generating the discard requests, thus generating the minimum number. If an error occurs when the request has been sent to the block device, then it will print a message and turn off the requests for that filesystem. If the problem is temporary, then you can use remount to turn the option back on again. There is also a nodiscard mount option so that you can use remount to turn discard requests off, if required. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Fix deadlock on journal flushSteven Whitehouse
This patch fixes a deadlock when the journal is flushed and there are dirty inodes other than the one which caused the journal flush. Originally the journal flushing code was trying to obtain the transaction glock while running the flush code for an inode glock. We no longer require the transaction glock at this point in time since we know that any attempt to get the transaction glock from another node will result in a journal flush. So if we are flushing the journal, we can be sure that the transaction lock is still cached from when the transaction was started. By inlining a version of gfs2_trans_begin() (minus the bit which gets the transaction glock) we can avoid the deadlock problems caused if there is a demote request queued up on the transaction glock. In addition I've also moved the umount rwsem so that it covers the glock workqueue, since it all demotions are done by this workqueue now. That fixes a bug on umount which I came across while fixing the original problem. Reported-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Fix error path ref counting for root inodeSteven Whitehouse
We were keeping hold of an extra ref to the root inode in one of the error paths, that resulted in a hang. Reported-by: Nate Straz <nstraz@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Tested-by: Robert Peterson <rpeterso@redhat.com>
2009-03-24GFS2: Remove unused field from glockSteven Whitehouse
The time stamp field is unused in the glock now that we are using a shrinker, so that we can remove it and save sizeof(unsigned long) bytes in each glock. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Merge lock_dlm module into GFS2Steven Whitehouse
This is the big patch that I've been working on for some time now. There are many reasons for wanting to make this change such as: o Reducing overhead by eliminating duplicated fields between structures o Simplifcation of the code (reduces the code size by a fair bit) o The locking interface is now the DLM interface itself as proposed some time ago. o Fewer lookups of glocks when processing replies from the DLM o Fewer memory allocations/deallocations for each glock o Scope to do further optimisations in the future (but this patch is more than big enough for now!) Please note that (a) this patch relates to the lock_dlm module and not the DLM itself, that is still a separate module; and (b) that we retain the ability to build GFS2 as a standalone single node filesystem with out requiring the DLM. This patch needs a lot of testing, hence my keeping it I restarted my -git tree after the last merge window. That way, this has the maximum exposure before its merged. This is (modulo a few minor bug fixes) the same patch that I've been posting on and off the the last three months and its passed a number of different tests so far. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>