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2020-06-05Merge branch 'gfs2-iopen' into for-nextAndreas Gruenbacher1-0/+7
2020-06-05gfs2: Turn gl_delete into a delayed workAndreas Gruenbacher1-0/+4
This requires flushing delayed work items in gfs2_make_fs_ro (which is called before unmounting a filesystem). When inodes are deleted and then recreated, pending gl_delete work items would have no effect because the inode generations will have changed, so we can cancel any pending gl_delete works before reusing iopen glocks. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05gfs2: Keep track of deleted inode generations in LVBsAndreas Gruenbacher1-0/+3
When deleting an inode, keep track of the generation of the deleted inode in the inode glock Lock Value Block (LVB). When trying to delete an inode remotely, check the last-known inode generation against the deleted inode generation to skip duplicate remote deletes. This avoids taking the resource group glock in order to verify the block type. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05gfs2: introduce new gfs2_glock_assert_withdrawBob Peterson1-0/+9
Before this patch, asserts based on glocks did not print the glock with the error. This patch introduces a new macro, gfs2_glock_assert_withdraw which first prints the glock, then takes the assert. This also changes a few glock asserts to the new macro. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2019-09-04gfs2: Use async glocks for renameBob Peterson1-0/+6
Because s_vfs_rename_mutex is not cluster-wide, multiple nodes can reverse the roles of which directories are "old" and which are "new" for the purposes of rename. This can cause deadlocks where two nodes end up waiting for each other. There can be several layers of directory dependencies across many nodes. This patch fixes the problem by acquiring all gfs2_rename's inode glocks asychronously and waiting for all glocks to be acquired. That way all inodes are locked regardless of the order. The timeout value for multiple asynchronous glocks is calculated to be the total of the individual wait times for each glock times two. Since gfs2_exchange is very similar to gfs2_rename, both functions are patched in the same way. A new async glock wait queue, sd_async_glock_wait, keeps a list of waiters for these events. If gfs2's holder_wake function detects an async holder, it wakes up any waiters for the event. The waiter only tests whether any of its requests are still pending. Since the glocks are sent to dlm asychronously, the wait function needs to check to see which glocks, if any, were granted. If a glock is granted by dlm (and therefore held), its minimum hold time is checked and adjusted as necessary, as other glock grants do. If the event times out, all glocks held thus far must be dequeued to resolve any existing deadlocks. Then, if there are any outstanding locking requests, we need to loop around and wait for dlm to respond to those requests too. After we release all requests, we return -ESTALE to the caller (vfs rename) which loops around and retries the request. Node1 Node2 --------- --------- 1. Enqueue A Enqueue B 2. Enqueue B Enqueue A 3. A granted 6. B granted 7. Wait for B 8. Wait for A 9. A times out (since Node 1 holds A) 10. Dequeue B (since it was granted) 11. Wait for all requests from DLM 12. B Granted (since Node2 released it in step 10) 13. Rename 14. Dequeue A 15. DLM Grants A 16. Dequeue A (due to the timeout and since we no longer have B held for our task). 17. Dequeue B 18. Return -ESTALE to vfs 19. VFS retries the operation, goto step 1. This release-all-locks / acquire-all-locks may slow rename / exchange down as both nodes struggle in the same way and do the same thing. However, this will only happen when there is contention for the same inodes, which ought to be rare. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2019-06-27gfs2: dump fsid when dumping glock problemsBob Peterson1-4/+7
Before this patch, if a glock error was encountered, the glock with the problem was dumped. But sometimes you may have lots of file systems mounted, and that doesn't tell you which file system it was for. This patch adds a new boolean parameter fsid to the dump_glock family of functions. For non-error cases, such as dumping the glocks debugfs file, the fsid is not dumped in order to keep lock dumps and glocktop as clean as possible. For all error cases, such as GLOCK_BUG_ON, the file system id is now printed. This will make it easier to debug. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398Thomas Gleixner1-4/+1
Based on 1 normalized pattern(s): this copyrighted material is made available to anyone wishing to use modify copy or redistribute it subject to the terms and conditions of the gnu general public license version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 44 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081038.653000175@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-23gfs: no need to check return value of debugfs_create functionsGreg Kroah-Hartman1-2/+2
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. There is no need to save the dentries for the debugfs files, so drop those variables to save a bit of space and make the code simpler. Cc: Bob Peterson <rpeterso@redhat.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: cluster-devel@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-12-12gfs2: Dump nrpages for inodes and their glocksBob Peterson1-1/+1
This patch is based on an idea from Steve Whitehouse. The idea is to dump the number of pages for inodes in the glock dumps. The additional locking required me to drop const from quite a few places. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2017-08-10gfs2: gfs2_evict_inode: Put glocks asynchronouslyAndreas Gruenbacher1-0/+2
gfs2_evict_inode is called to free inodes under memory pressure. The function calls into DLM when an inode's last cluster-wide reference goes away (remote unlink) and to release the glock and associated DLM lock before finally destroying the inode. However, if DLM is blocked on memory to become available, calling into DLM again will deadlock. Avoid that by decoupling releasing glocks from destroying inodes in that case: with gfs2_glock_queue_put, glocks will be dequeued asynchronously in work queue context, when the associated inodes have likely already been destroyed. With this change, inodes can end up being unlinked, remote-unlink can be triggered, and then the inode can be reallocated before all remote-unlink callbacks are processed. To detect that, revalidate the link count in gfs2_evict_inode to make sure we're not deleting an allocated, referenced inode. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-07-21GFS2: Introduce helper for clearing gl_objectBob Peterson1-0/+34
This patch introduces a new helper function in glock.h that clears gl_object, with an added integrity check. An additional integrity check has been added to glock_set_object, plus comments. This is step 1 in a series to ensure gl_object integrity. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2017-07-05gfs2: Get rid of flush_delayed_work in gfs2_evict_inodeAndreas Gruenbacher1-0/+7
So far, gfs2_evict_inode clears gl->gl_object and then flushes the glock work queue to make sure that inode glops which dereference gl->gl_object have finished running before the inode is destroyed. However, flushing the work queue may do more work than needed, and in particular, it may call into DLM, which we want to avoid here. Use a bit lock (GIF_GLOP_PENDING) to synchronize between the inode glops and gfs2_evict_inode instead to get rid of the flushing. In addition, flush the work queues of existing glocks before reusing them for new inodes to get those glocks into a known state: the glock state engine currently doesn't handle glock re-appropriation correctly. (We may be able to fix the glock state engine instead later.) Based on a patch by Steven Whitehouse <swhiteho@redhat.com>. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2016-06-27gfs2: Lock holder cleanupAndreas Gruenbacher1-0/+10
Make the code more readable by cleaning up the different ways of initializing lock holders and checking for initialized lock holders: mark lock holders as uninitialized by setting the holder's glock to NULL (gfs2_holder_mark_uninitialized) instead of zeroing out the entire object or using a separate flag. Recognize initialized holders by their non-NULL glock (gfs2_holder_initialized). Don't zero out holder objects which are immeditiately initialized via gfs2_holder_init or gfs2_glock_nq_init. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2015-12-14GFS2: Reduce size of incore inodeBob Peterson1-13/+13
This patch makes no functional changes. Its goal is to reduce the size of the gfs2 inode in memory by rearranging structures and changing the size of some variables within the structure. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2015-10-29gfs2: Remove gl_spin defineAndreas Gruenbacher1-2/+2
Commit e66cf161 replaced the gl_spin spinlock in struct gfs2_glock with a gl_lockref lockref and defined gl_spin as gl_lockref.lock (the spinlock in gl_lockref). Remove that define to make the references to gl_lockref.lock more obvious. Signed-off-by: Andreas Gruenbacher <andreas.gruenbacher@gmail.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2014-01-16GFS2: Don't use ENOBUFS when ENOMEM is the correct error codeSteven Whitehouse1-1/+1
Al Viro has tactfully pointed out that we are using the incorrect error code in some cases. This patch fixes that, and also removes the (unused) return value for glock dumping. > * gfs2_iget() - ENOBUFS instead of ENOMEM. ENOBUFS is > "No buffer space available (POSIX.1 (XSI STREAMS option))" and since > we don't support STREAMS it's probably fair game, but... what the hell? Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
2013-10-15GFS2: Use lockref for glocksSteven Whitehouse1-2/+0
Currently glocks have an atomic reference count and also a spinlock which covers various internal fields, such as the state. This intent of this patch is to replace the spinlock and the atomic reference count with a lockref structure. This contains a spinlock which we can continue to use as before, and a reference counter which is used in conjuction with the spinlock to replace the previous atomic counter. As a result of this there are some new rules for reference counting on glocks. We need to distinguish between reference count changes under gl_spin (which are now just increment or decrement of the new counter, provided the count cannot hit zero) and those which are outside of gl_spin, but which now take gl_spin internally. The conversion is relatively straight forward. There is probably some further clean up which can be done, but the priority at this stage is to make the change in as simple a manner as possible. A consequence of this change is that the reference count is being decoupled from the lru list processing. This should allow future adoption of the lru_list code with glocks in due course. The reason for using the "dead" state and not just relying on 0 being the "invalid state" is so that in due course 0 ref counts can be allowable. The intent is to eventually be able to remove the ref count changes which are currently hidden away in state_change(). Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-04-08GFS2: Remove gfs2_refresh_inode from inode creation pathSteven Whitehouse1-1/+0
The original method for creating inodes used in GFS2 was to fill out a buffer, with all the information, and then to read that buffer into the in-core inode, using gfs2_refresh_inode() The problem with this approach is that all the inode's fields need to be calculated ahead of time, and were stored in various variables making the code rather complicated. The new approach is simply to allocate the in-core inode earlier and fill in as many fields as possible ahead of time. These can then be used to initilise the on disk representation. The code has been working towards the point where it is possible to remove gfs2_refresh_inode() because all the fields are correctly initialised ahead of time. We've now reached that milestone, and have reversed the order of setting up the in core and on disk inodes. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07GFS2: Review bug traps in glops.cSteven Whitehouse1-27/+27
Two of the bug traps here could really be warnings. The others are converted from BUG() to GLOCK_BUG_ON() since we'll most likely need to know the glock state in order to debug any issues which arise. As a result of this, __dump_glock has to be renamed and is no longer static. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-01-11GFS2: dlm based recovery coordinationDavid Teigland1-2/+5
This new method of managing recovery is an alternative to the previous approach of using the userland gfs_controld. - use dlm slot numbers to assign journal id's - use dlm recovery callbacks to initiate journal recovery - use a dlm lock to determine the first node to mount fs - use a dlm lock to track journals that need recovery Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-31treewide: use __printf not __attribute__((format(printf,...)))Joe Perches1-1/+1
Standardize the style for compiler based printf format verification. Standardized the location of __printf too. Done via script and a little typing. $ grep -rPl --include=*.[ch] -w "__attribute__" * | \ grep -vP "^(tools|scripts|include/linux/compiler-gcc.h)" | \ xargs perl -n -i -e 'local $/; while (<>) { s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf\s*,\s*(.+)\s*,\s*(.+)\s*\)\s*\)\s*\)/__printf($1, $2)/g ; print; }' [akpm@linux-foundation.org: revert arch bits] Signed-off-by: Joe Perches <joe@perches.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-15GFS2: Automatically adjust glock min hold timeBob Peterson1-0/+6
This patch is a performance improvement for GFS2 in a clustered environment. It makes the glock hold time self-adjusting. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-04-20GFS2: Alter point of entry to glock lru list for glocks with an address_spaceSteven Whitehouse1-2/+1
Rather than allowing the glocks to be scheduled for possible reclaim as soon as they have exited the journal, this patch delays their entry to the list until the glocks in question are no longer in use. This means that we will rely on the vm for writeback of all dirty data and metadata from now on. When glocks are added to the lru list they should be freeable much faster since all the I/O required to free them should have already been completed. This should lead to much better I/O patterns under low memory conditions. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-09GFS2: Fix glock deallocation raceSteven Whitehouse1-1/+1
This patch fixes a race in deallocating glocks which was introduced in the RCU glock patch. We need to ensure that the glock count is kept correct even in the case that there is a race to add a new glock into the hash table. Also, to avoid having to wait for an RCU grace period, the glock counter can be decremented before call_rcu() is called. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-01-21GFS2: Use RCU for glock hash tableSteven Whitehouse1-21/+18
This has a number of advantages: - Reduces contention on the hash table lock - Makes the code smaller and simpler - Should speed up glock dumps when under load - Removes ref count changing in examine_bucket - No longer need hash chain lock in glock_put() in common case There are some further changes which this enables and which we may do in the future. One is to look at using SLAB_RCU, and another is to look at using a per-cpu counter for the per-sb glock counter, since that is touched twice in the lifetime of each glock (but only used at umount time). Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-30GFS2: Remove duplicate #defines from glock.hSteven Whitehouse1-14/+0
There are a number of duplicated #defines in glock.h plus one which is unused. This removes the extra definitions. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Clean up of gdlm_lock functionSteven Whitehouse1-8/+4
The DLM never returns -EAGAIN in response to dlm_lock(), and even if it did, the test in gdlm_lock() was wrong anyway. Once that test is removed, it is possible to greatly simplify this code by simply using a "normal" error return code (0 for success). We then no longer need the LM_OUT_ASYNC return code which can be removed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: fs/gfs2/glock.h: Add __attribute__((format(printf,2,3)) to gfs2_print_dbgJoe Perches1-0/+2
Functions that use printf formatting, especially those that use %pV, should have their uses of printf format and arguments checked by the compiler. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-10-18GFS2: fixed typoAndrea Gelmini1-1/+1
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-03-01GFS2: Metadata address space clean upSteven Whitehouse1-0/+7
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 <swhiteho@redhat.com>
2010-02-03GFS2: Extend umount wait coverage to full glock lifetimeSteven Whitehouse1-1/+1
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 <swhiteho@redhat.com>
2009-12-03GFS2: Remove obsolete code in quota.cSteven Whitehouse1-9/+0
There is no point in testing for GLF_DEMOTE here, we might as well always release the glock at that point. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-07-30GFS2: remove dcache entries for remote deleted inodesBenjamin Marzinski1-0/+3
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 <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-03-24GFS2: Merge lock_dlm module into GFS2Steven Whitehouse1-4/+123
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>
2009-01-05Revert "GFS2: Fix use-after-free bug on umount"Steven Whitehouse1-1/+1
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 <swhiteho@redhat.com>
2009-01-05GFS2: Fix use-after-free bug on umountSteven Whitehouse1-1/+1
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 <swhiteho@redhat.com>
2009-01-05GFS2: Kill two daemons with one patchSteven Whitehouse1-1/+0
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 <swhiteho@redhat.com>
2009-01-05GFS2: Fix "truncate in progress" hangSteven Whitehouse1-0/+1
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 <swhiteho@redhat.com>
2008-09-18GFS2: high time to take some time over atimeSteven Whitehouse1-1/+0
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>
2008-06-27[GFS2] Remove remote lock dropping codeSteven Whitehouse1-1/+1
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[GFS2] Clean up the glock coreSteven Whitehouse1-5/+4
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>
2008-03-31[GFS2] Fix a page lock / glock deadlockSteven Whitehouse1-7/+6
We've previously been using a "try lock" in readpage on the basis that it would prevent deadlocks due to the inverted lock ordering (our normal lock ordering is glock first and then page lock). Unfortunately tests have shown that this isn't enough. If the glock has a demote request queued such that run_queue() in the glock code tries to do a demote when its called under readpage then it will try and write out all the dirty pages which requires locking them. This then deadlocks with the page locked by readpage. The solution is to always require two calls into readpage. The first unlocks the page, gets the glock and returns AOP_TRUNCATED_PAGE, the second does the actual readpage and unlocks the glock & page as required. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-03-31[GFS2] make gfs2_glock_hold() staticAdrian Bunk1-1/+0
gfs2_glock_hold() can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-02-07gfs2: make gfs2_holder.gh_owner_pid be a struct pid *Pavel Emelyanov1-1/+3
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>
2007-10-10[GFS2] flocks from same process trip kernel BUG at fs/gfs2/glock.c:1118!Abhijith Das1-0/+1
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[GFS2] Reduce number of gfs2_scand processes to oneSteven Whitehouse1-2/+2
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>
2007-07-09[GFS2] Fix deallocation issuesAbhijith Das1-0/+1
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>
2007-05-21Detach sched.h from mm.hAlexey Dobriyan1-0/+1
First thing mm.h does is including sched.h solely for can_do_mlock() inline function which has "current" dereference inside. By dealing with can_do_mlock() mm.h can be detached from sched.h which is good. See below, why. This patch a) removes unconditional inclusion of sched.h from mm.h b) makes can_do_mlock() normal function in mm/mlock.c c) exports can_do_mlock() to not break compilation d) adds sched.h inclusions back to files that were getting it indirectly. e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were getting them indirectly Net result is: a) mm.h users would get less code to open, read, preprocess, parse, ... if they don't need sched.h b) sched.h stops being dependency for significant number of files: on x86_64 allmodconfig touching sched.h results in recompile of 4083 files, after patch it's only 3744 (-8.3%). Cross-compile tested on all arm defconfigs, all mips defconfigs, all powerpc defconfigs, alpha alpha-up arm i386 i386-up i386-defconfig i386-allnoconfig ia64 ia64-up m68k mips parisc parisc-up powerpc powerpc-up s390 s390-up sparc sparc-up sparc64 sparc64-up um-x86_64 x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig as well as my two usual configs. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-01[GFS2] Red Hat bz 228540: owner referencesRobert Peterson1-1/+1
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[GFS2] Fix bz 224480 and cleanup glock demotion codeSteven Whitehouse1-1/+1
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>