path: root/fs/gfs2/glock.c
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2010-03-01GFS2: print glock numbers in hexBob Peterson
This patch changes glock numbers from printing in decimal to hex. Since DLM prints corresponding resource IDs in hex, it makes debugging easier. Signed-off-by: Bob Peterson <> Signed-off-by: Steven Whitehouse <>
2010-03-01GFS2: Remove loopy umount codeSteven Whitehouse
As a consequence of the previous patch, we can now remove the loop which used to be required due to the circular dependency between the inodes and glocks. Instead we can just invalidate the inodes, and then clear up any glocks which are left. Also we no longer need the rwsem since there is no longer any danger of the inode invalidation calling back into the glock code (and from there back into the inode code). Signed-off-by: Steven Whitehouse <>
2010-03-01GFS2: Metadata address space clean upSteven Whitehouse
Since the start of GFS2, an "extra" inode has been used to store the metadata belonging to each inode. The only reason for using this inode was to have an extra address space, the other fields were unused. This means that the memory usage was rather inefficient. The reason for keeping each inode's metadata in a separate address space is that when glocks are requested on remote nodes, we need to be able to efficiently locate the data and metadata which relating to that glock (inode) in order to sync or sync and invalidate it (depending on the remotely requested lock mode). This patch adds a new type of glock, which has in addition to its normal fields, has an address space. This applies to all inode and rgrp glocks (but to no other glock types which remain as before). As a result, we no longer need to have the second inode. This results in three major improvements: 1. A saving of approx 25% of memory used in caching inodes 2. A removal of the circular dependency between inodes and glocks 3. No confusion between "normal" and "metadata" inodes in super.c Although the first of these is the more immediately apparent, the second is just as important as it now enables a number of clean ups at umount time. Those will be the subject of future patches. Signed-off-by: Steven Whitehouse <>
2010-02-03GFS2: Extend umount wait coverage to full glock lifetimeSteven Whitehouse
Although all glocks are, by the time of the umount glock wait, scheduled for demotion, some of them haven't made it far enough through the process for the original set of waiting code to wait for them. This extends the ref count to the whole glock lifetime in order to ensure that the waiting does catch all glocks. It does make it a bit more invasive, but it seems the only sensible solution at the moment. Signed-off-by: Steven Whitehouse <>
2009-12-03GFS2: Fix glock refcount issuesSteven Whitehouse
This patch fixes some ref counting issues. Firstly by moving the point at which we drop the ref count after a dlm lock operation has completed we ensure that we never call gfs2_glock_hold() on a lock with a zero ref count. Secondly, by using atomic_dec_and_lock() in gfs2_glock_put() we ensure that at no time will a glock with zero ref count appear on the lru_list. That means that we can remove the check for this in our shrinker (which was racy). Signed-off-by: Steven Whitehouse <>
2009-12-03GFS2: Fix potential race in glock codeSteven Whitehouse
We need to be careful of the ordering between clearing the GLF_LOCK bit and scheduling the workqueue. Signed-off-by: Steven Whitehouse <>
2009-07-30GFS2: remove dcache entries for remote deleted inodesBenjamin Marzinski
When a file is deleted from a gfs2 filesystem on one node, a dcache entry for it may still exist on other nodes in the cluster. If this happens, gfs2 will be unable to free this file on disk. Because of this, it's possible to have a gfs2 filesystem with no files on it and no free space. With this patch, when a node receives a callback notifying it that the file is being deleted on another node, it schedules a new workqueue thread to remove the file's dcache entry. Signed-off-by: Benjamin Marzinski <> Signed-off-by: Steven Whitehouse <>
2009-07-30GFS2: Don't put unlikely reclaim candidates on the reclaim list.Benjamin Marzinski
GFS2 was placing far too many glocks on the reclaim list that were not good candidates for freeing up from cache. These locks would sit there and repeatedly get scanned to see if they could be reclaimed, wasting a lot of time when there was memory pressure. This fix does more checks on the locks to see if they are actually likely to be removable from cache. Signed-off-by: Benjamin Marzinski <> Signed-off-by: Steven Whitehouse <>
2009-07-30GFS2: Fix panic in glock memory shrinkerBenjamin Marzinski
It is possible for gfs2_shrink_glock_memory() to check a glock for demotion that's in the process of being freed by gfs2_glock_put(). In this case, gfs2_shrink_glock_memory() will acquire a new reference to this glock, and then try to free the glock itself when it drops the refernce. To solve this, gfs2_shrink_glock_memory() just needs to check if the glock is in the process of being freed, and if so skip it without ever unlocking the lru_lock. Signed-off-by: Benjamin Marzinski <> Acked-by: Bob Peterson <> Signed-off-by: Steven Whitehouse <>
2009-07-30GFS2: Shrink the shrinkerSteven Whitehouse
This patch removes some of the special cases that the shrinker was trying to deal with. As a result we leave fewer items on the list and none at all which cannot be demoted. This makes the list scanning more efficient and solves some issues seen with large numbers of inodes. Signed-off-by: Steven Whitehouse <>
2009-06-12GFS2: Add tracepointsSteven Whitehouse
This patch adds the ability to trace various aspects of the GFS2 filesystem. The trace points are divided into three groups, glocks, logging and bmap. These points have been chosen because they allow inspection of the major internal functions of GFS2 and they are also generic enough that they are unlikely to need any major changes as the filesystem evolves. Signed-off-by: Steven Whitehouse <>
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 <>
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 <>
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 <>
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 <>
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 <> Signed-off-by: Steven Whitehouse <>
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 <>
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 <>
2009-01-05GFS2: Use DEFINE_SPINLOCKJulia Lawall
SPIN_LOCK_UNLOCKED is deprecated. The following makes the change suggested in Documentation/spinlocks.txt The semantic patch that makes this change is as follows: ( // <smpl> @@ declarer name DEFINE_SPINLOCK; identifier xxx_lock; @@ - spinlock_t xxx_lock = SPIN_LOCK_UNLOCKED; + DEFINE_SPINLOCK(xxx_lock); // </smpl> Signed-off-by: Julia Lawall <> Signed-off-by: Steven Whitehouse <>
2009-01-05Revert "GFS2: Fix use-after-free bug on umount"Steven Whitehouse
This reverts commit 78802499912f1ba31ce83a94c55b5a980f250a43. The original patch is causing problems in relation to order of operations at umount in relation to jdata files. I need to fix this a different way. Signed-off-by: Steven Whitehouse <>
2009-01-05GFS2: Fix use-after-free bug on umountSteven Whitehouse
There was a use-after-free with the GFS2 super block during umount. This patch moves almost all of the umount code from ->put_super into ->kill_sb, the only bit that cannot be moved being the glock hash clearing which has to remain as ->put_super due to umount ordering requirements. As a result its now obvious that the kfree is the final operation, whereas before it was hidden in ->put_super. Also gfs2_jindex_free is then only referenced from a single file so thats moved and marked static too. Signed-off-by: Steven Whitehouse <>
2009-01-05GFS2: Move four functions from super.cSteven Whitehouse
The functions which are being moved can all be marked static in their new locations, since they only have a single caller each. Their new locations are more logical than before and some of the functions are small enough that the compiler might well inline them. Signed-off-by: Steven Whitehouse <>
2009-01-05GFS2: Kill two daemons with one patchSteven Whitehouse
This patch removes the two daemons, gfs2_scand and gfs2_glockd and replaces them with a shrinker which is called from the VM. The net result is that GFS2 responds better when there is memory pressure, since it shrinks the glock cache at the same rate as the VFS shrinks the dcache and icache. There are no longer any time based criteria for shrinking glocks, they are kept until such time as the VM asks for more memory and then we demote just as many glocks as required. There are potential future changes to this code, including the possibility of sorting the glocks which are to be written back into inode number order, to get a better I/O ordering. It would be very useful to have an elevator based workqueue implementation for this, as that would automatically deal with the read I/O cases at the same time. This patch is my answer to Andrew Morton's remark, made during the initial review of GFS2, asking why GFS2 needs so many kernel threads, the answer being that it doesn't :-) This patch is a net loss of about 200 lines of code. Signed-off-by: Steven Whitehouse <>
2009-01-05GFS2: Fix "truncate in progress" hangSteven Whitehouse
Following on from the recent clean up of gfs2_quotad, this patch moves the processing of "truncate in progress" inodes from the glock workqueue into gfs2_quotad. This fixes a hang due to the "truncate in progress" processing requiring glocks in order to complete. It might seem odd to use gfs2_quotad for this particular item, but we have to use a pre-existing thread since creating a thread implies a GFP_KERNEL memory allocation which is not allowed from the glock workqueue context. Of the existing threads, gfs2_logd and gfs2_recoverd may deadlock if used for this operation. gfs2_scand and gfs2_glockd are both scheduled for removal at some (hopefully not too distant) future point. That leaves only gfs2_quotad whose workload is generally fairly light and is easily adapted for this extra task. Also, as a result of this change, it opens the way for a future patch to make the reading of the inode's information asynchronous with respect to the glock workqueue, which is another improvement that has been on the list for some time now. Signed-off-by: Steven Whitehouse <>
2009-01-05GFS2: sparse annotation of gl->gl_spinHarvey Harrison
fs/gfs2/glock.c:308:5: warning: context problem in 'do_promote': '_spin_unlock' expected different context fs/gfs2/glock.c:308:5: context '*gl+28': wanted >= 1, got 0 fs/gfs2/glock.c:529:2: warning: context problem in 'do_xmote': '_spin_unlock' expected different context fs/gfs2/glock.c:529:2: context '*gl+28': wanted >= 1, got 0 fs/gfs2/glock.c:925:3: warning: context problem in 'add_to_queue': '_spin_unlock' expected different context fs/gfs2/glock.c:925:3: context '*gl+28': wanted >= 1, got 0 Signed-off-by: Harvey Harrison <> Signed-off-by: Steven Whitehouse <>
2008-09-18GFS2: high time to take some time over atimeSteven Whitehouse
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 <>
2008-09-05GFS2: Fix race relating to glock min-hold timeSteven Whitehouse
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 <>
2008-08-13GFS2: Fix debugfs glock file iteratorSteven Whitehouse
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 <>
2008-07-07[GFS2] Allow local DF locks when holding a cached EX glockSteven Whitehouse
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 <>
2008-07-07[GFS2] Fix delayed demote raceSteven Whitehouse
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 <> Cc: Bob Peterson <>
2008-06-27[GFS2] Remove remote lock dropping codeSteven Whitehouse
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 <>
2008-06-27[GFS2] No lock_nolockSteven Whitehouse
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 <> Cc: David Teigland <>
2008-06-27[GFS2] Clean up the glock coreSteven Whitehouse
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 <> Cc: Bob Peterson <>
2008-03-31[GFS2] Invalidate cache at correct pointBenjamin Marzinski
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 <> Signed-off-by: Steven Whitehouse <>
2008-03-31[GFS2] Fix bug where we called drop_bh incorrectlySteven Whitehouse
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 <> Cc: Bob Peterson <>
2008-03-31[GFS2] Remove rgrp and glock version numbersBob Peterson
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 <> Signed-off-by: Steven Whitehouse <>
2008-03-31[GFS2] Remove lm.[ch] and distribute contentSteven Whitehouse
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 <>
2008-03-31[GFS2] Eliminate gl_req_bhBob Peterson
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 <> Signed-off-by: Steven Whitehouse <>
2008-03-31[GFS2] Get rid of gl_waiters2Bob Peterson
This patch reduces memory by replacing the int variable gl_waiters2 by a single bit in the gl_flags. Signed-off-by: Bob Peterson <> Signed-off-by: Steven Whitehouse <>
2008-03-31[GFS2] make gfs2_glock_hold() staticAdrian Bunk
gfs2_glock_hold() can now become static. Signed-off-by: Adrian Bunk <> Signed-off-by: Steven Whitehouse <>
2008-03-31[GFS2] Only wake the reclaim daemon if we need toBob Peterson
This patch only wakes up the glock reclaim daemon if there is actually something to be reclaimed. Signed-off-by: Bob Peterson <> Signed-off-by: Steven Whitehouse <>
2008-02-07gfs2: make gfs2_glock.gl_owner_pid be a struct pid *Pavel Emelyanov
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 <> Cc: "Eric W. Biederman" <> Acked-by: Steven Whitehouse <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2008-02-07gfs2: make gfs2_holder.gh_owner_pid be a struct pid *Pavel Emelyanov
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 <> Cc: "Eric W. Biederman" <> Acked-by: Steven Whitehouse <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2008-01-25[GFS2] Reorganize function gfs2_glmutex_lockBob Peterson
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 <> Signed-off-by: Steven Whitehouse <>
2008-01-25[GFS2] Fix runtime issue with UP kernelsFabio Massimo Di Nitto
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 <> Cc: David S. Miller <> Signed-off-by: Steven Whitehouse <>
2008-01-25[GFS2] Don't add glocks to the journalSteven Whitehouse
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 <>
2008-01-25[GFS2] Remove flags no longer requiredSteven Whitehouse
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 <>
2008-01-25[GFS2] Reorder writeback for glock syncSteven Whitehouse
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 <>
2008-01-25[GFS2] Remove "reclaim limit"Steven Whitehouse
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 <>
2008-01-25[GFS2] Handle multiple glock demote requestsWendy Cheng
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 <> Signed-off-by: Steven Whitehouse <>