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* Merge tag 'gfs2-merge-window' of ↵Linus Torvalds2014-06-041-19/+32
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw into next Pull gfs2 updates from Steven Whitehouse: "This must be about the smallest merge window patch set ever for GFS2. It is probably also the first one without a single patch from me. That is down to a combination of factors, and I have some things in the works that are not quite ready yet, that I hope to put in next time around. Returning to what is here this time... we have 3 patches which fix various warnings. Two are bug fixes (for quotas and also a rare recovery race condition). The final patch, from Ben Marzinski, is an important change in the freeze code which has been in progress for some time. This removes the need to take and drop the transaction lock for every single transaction, when the only time it was used, was at file system freeze time. Ben's patch integrates the freeze operation into the journal flush code as an alternative with lower overheads and also lands up resolving some difficult to fix races at the same time" * tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw: GFS2: Prevent recovery before the local journal is set GFS2: fs/gfs2/file.c: kernel-doc warning fixes GFS2: fs/gfs2/bmap.c: kernel-doc warning fixes GFS2: remove transaction glock GFS2: lops.c: replace 0 by NULL for pointers GFS2: quotas not being refreshed in gfs2_adjust_quota
| * GFS2: remove transaction glockBenjamin Marzinski2014-05-141-19/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GFS2 has a transaction glock, which must be grabbed for every transaction, whose purpose is to deal with freezing the filesystem. Aside from this involving a large amount of locking, it is very easy to make the current fsfreeze code hang on unfreezing. This patch rewrites how gfs2 handles freezing the filesystem. The transaction glock is removed. In it's place is a freeze glock, which is cached (but not held) in a shared state by every node in the cluster when the filesystem is mounted. This lock only needs to be grabbed on freezing, and actions which need to be safe from freezing, like recovery. When a node wants to freeze the filesystem, it grabs this glock exclusively. When the freeze glock state changes on the nodes (either from shared to unlocked, or shared to exclusive), the filesystem does a special log flush. gfs2_log_flush() does all the work for flushing out the and shutting down the incore log, and then it tries to grab the freeze glock in a shared state again. Since the filesystem is stuck in gfs2_log_flush, no new transaction can start, and nothing can be written to disk. Unfreezing the filesytem simply involes dropping the freeze glock, allowing gfs2_log_flush() to grab and then release the shared lock, so it is cached for next time. However, in order for the unfreezing ioctl to occur, gfs2 needs to get a shared lock on the filesystem root directory inode to check permissions. If that glock has already been grabbed exclusively, fsfreeze will be unable to get the shared lock and unfreeze the filesystem. In order to allow the unfreeze, this patch makes gfs2 grab a shared lock on the filesystem root directory during the freeze, and hold it until it unfreezes the filesystem. The functions which need to grab a shared lock in order to allow the unfreeze ioctl to be issued now use the lock grabbed by the freeze code instead. The freeze and unfreeze code take care to make sure that this shared lock will not be dropped while another process is using it. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* | arch: Mass conversion of smp_mb__*()Peter Zijlstra2014-04-181-1/+1
|/ | | | | | | | | | | Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* GFS2: Move log buffer lists into transactionSteven Whitehouse2014-02-241-0/+2
| | | | | | | | | | | | | | | Over time, we hope to be able to improve the concurrency available in the log code. This is one small step towards that, by moving the buffer lists from the super block, and into the transaction structure, so that each transaction builds its own buffer lists. At transaction commit time, the buffer lists are merged into the currently accumulating transaction. That transaction then is passed into the before and after commit functions at journal flush time. Thus there should be no change in overall behaviour yet. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Don't use ENOBUFS when ENOMEM is the correct error codeSteven Whitehouse2014-01-161-4/+2
| | | | | | | | | | | | | 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>
* GFS2: Use only a single address space for rgrpsSteven Whitehouse2014-01-031-8/+10
| | | | | | | | | | | | | | | | | Prior to this patch, GFS2 had one address space for each rgrp, stored in the glock. This patch changes them to use a single address space in the super block. This therefore saves (sizeof(struct address_space) * nr_of_rgrps) bytes of memory and for large filesystems, that can be significant. It would be nice to be able to do something similar and merge the inode metadata address space into the same global address space. However, that is rather more complicated as the on-disk location doesn't have a 1:1 mapping with the inodes in general. So while it could be done, it will be a more complicated operation as it requires changing a lot more code paths. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Use range based functions for rgrp sync/invalidationSteven Whitehouse2014-01-031-3/+3
| | | | | | | | | | | | | | | | | | | | Each rgrp header is represented as a single extent on disk, so we can calculate the position within the address space, since we are using address spaces mapped 1:1 to the disk. This means that it is possible to use the range based versions of filemap_fdatawrite/wait and for invalidating the page cache. Our eventual intent is to then be able to merge the address spaces used for rgrps into a single address space, rather than to have one for each glock, saving memory and reducing complexity. Since during umount, the rgrp structures are disposed of before the glocks, we need to store the extent information in the glock so that is is available for a final invalidation. This patch uses a field which is otherwise unused in rgrp glocks to do that, so that we do not have to expand the size of a glock. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Wait for async DIO in glock state changesSteven Whitehouse2013-12-201-2/+8
| | | | | | | | | | | | | | | | | | We need to wait for any outstanding DIO to complete in a couple of situations. Firstly, in case we are changing out of deferred mode (in inode_go_sync) where GLF_DIRTY will not be set. That call could be prefixed with a test for gl_state == LM_ST_DEFERRED but it doesn't seem worth it bearing in mind that the test for outstanding DIO is very quick anyway, in the usual case that there is none. The second case is in inode_go_lock which will catch the cases where we have a cached EX lock, but where we grant deferred locks against it so that there is no glock state transistion. We only need to wait if the state is not deferred, since DIO is valid anyway in that state. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Use lockref for glocksSteven Whitehouse2013-10-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* GFS2: don't overrun reserved revokesBenjamin Marzinski2013-08-191-5/+13
| | | | | | | | | | | | | | | | | | | When run during fsync, a gfs2_log_flush could happen between the time when gfs2_ail_flush checked the number of blocks to revoke, and when it actually started the transaction to do those revokes. This occassionally caused it to need more revokes than it reserved, causing gfs2 to crash. Instead of just reserving enough revokes to handle the blocks that currently need them, this patch makes gfs2_ail_flush reserve the maximum number of revokes it can, without increasing the total number of reserved log blocks. This patch also passes the number of reserved revokes to __gfs2_ail_flush() so that it doesn't go over its limit and cause a crash like we're seeing. Non-fsync calls to __gfs2_ail_flush will still cause a BUG() necessary revokes are skipped. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: aggressively issue revokes in gfs2_log_flushBenjamin Marzinski2013-06-191-8/+0
| | | | | | | | | | | | | | | | | | | | This patch looks at all the outstanding blocks in all the transactions on the log, and moves the completed ones to the ail2 list. Then it issues revokes for these blocks. This will hopefully speed things up in situations where there is a lot of contention for glocks, especially if they are acquired serially. revoke_lo_before_commit will issue at most one log block's full of these preemptive revokes. The amount of reserved log space that gfs2_log_reserve() ignores has been incremented to allow for this extra block. This patch also consolidates the common revoke instructions into one function, gfs2_add_revoke(). Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Add origin indicator to glock callbacksSteven Whitehouse2013-04-101-2/+2
| | | | | | | | | | | | | | | This patch adds a bool indicating whether the demote request was originated locally or remotely. This is then used by the iopen ->go_callback() to make 100% sure that it will only respond to remote callbacks. Since ->evict_inode() uses GL_NOCACHE when it attempts to get an exclusive lock on the iopen lock, this may result in extra scheduling of the workqueue in case that the exclusive promotion request failed. This patch prevents that from happening. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* gfs2: Convert uids and gids between dinodes and vfs inodes.Eric W. Biederman2013-02-131-2/+2
| | | | | | | | | | | | | | When reading dinodes from the disk convert uids and gids into kuids and kgids to store in vfs data structures. When writing to dinodes to the disk convert kuids and kgids in the in memory structures into plain uids and gids. For now all on disk data structures are assumed to be stored in the initial user namespace. Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* GFS2: only use lvb on glocks that need itDavid Teigland2012-11-151-1/+2
| | | | | | | | | Save the effort of allocating, reading and writing the lvb for most glocks that do not use it. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Rename glops go_xmote_th to go_syncBob Peterson2012-11-071-3/+3
| | | | | | | | | | [Editorial: This is a nit, but has been a minor irritation for a long time:] This patch renames glops structure item for go_xmote_th to go_sync. The functionality is unchanged; it's just for readability. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Review bug traps in glops.cSteven Whitehouse2012-11-071-5/+5
| | | | | | | | | | 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>
* GFS2: fix s_writers.counter imbalance in gfs2_ail_empty_glEric Sandeen2012-09-241-0/+1
| | | | | | | | | | | | gfs2_ail_empty_gl() contains an "inline version" of gfs2_trans_begin(), so it needs an explicit sb_start_intwrite() as well, to balance the sb_end_intwrite() which will be called by gfs2_trans_end(). With this, xfstest 068 passes on lock_nolock local gfs2. Without it, we reach a writer count of -1 and get stuck. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Remove redundant metadata block type checkBob Peterson2012-05-081-5/+0
| | | | | | | | This patch removes a redundant metadata block check. See description below. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Remove bd_list_trSteven Whitehouse2012-04-241-1/+0
| | | | | | | | | | | | | | | This is another clean up in the logging code. This per-transaction list was largely unused. Its main function was to ensure that the number of buffers in a transaction was correct, however that counter was only used to check the number of buffers in the bd_list_tr, plus an assert at the end of each transaction. With the assert now changed to use the calculated buffer counts, we can remove both bd_list_tr and its associated counter. This should make the code easier to understand as well as shrinking a couple of structures. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* filesystems: add set_nlink()Miklos Szeredi2011-11-021-1/+1
| | | | | | | | | Replace remaining direct i_nlink updates with a new set_nlink() updater function. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* GFS2: Fix AIL flush issue during fsyncSteven Whitehouse2011-10-211-16/+16
| | | | | | | | | | | | | | Unfortunately, it is not enough to just ignore locked buffers during the AIL flush from fsync. We need to be able to ignore all buffers which are locked, dirty or pinned at this stage as they might have been added subsequent to the log flush earlier in the fsync function. In addition, this means that we no longer need to rely on i_mutex to keep out writes during fsync, so we can, as a side-effect, remove that protection too. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Tested-By: Abhijith Das <adas@redhat.com>
* GFS2: Make resource groups "append only" during life of fsSteven Whitehouse2011-10-211-10/+6
| | | | | | | | | | | | | | | | | | | | | Since we have ruled out supporting online filesystem shrink, it is possible to make the resource group list append only during the life of a super block. This gives several benefits: Firstly, we only need to read new rindex elements as they are added rather than needing to reread the whole rindex file each time one element is added. Secondly, the rindex glock can be held for much shorter periods of time, and is completely removed from the fast path for allocations. The lock is taken in shared mode only when updating the resource groups when the first allocation occurs, and after a grow has taken place. Thirdly, this results in a reduction in code size, and everything gets a lot simpler to understand in this area. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count schemeBob Peterson2011-10-211-29/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here is an update of Bob's original rbtree patch which, in addition, also resolves the rather strange ref counting that was being done relating to the bitmap blocks. Originally we had a dual system for journaling resource groups. The metadata blocks were journaled and also the rgrp itself was added to a list. The reason for adding the rgrp to the list in the journal was so that the "repolish clones" code could be run to update the free space, and potentially send any discard requests when the log was flushed. This was done by comparing the "cloned" bitmap with what had been written back on disk during the transaction commit. Due to this, there was a requirement to hang on to the rgrps' bitmap buffers until the journal had been flushed. For that reason, there was a rather complicated set up in the ->go_lock ->go_unlock functions for rgrps involving both a mutex and a spinlock (the ->sd_rindex_spin) to maintain a reference count on the buffers. However, the journal maintains a reference count on the buffers anyway, since they are being journaled as metadata buffers. So by moving the code which deals with the post-journal accounting for bitmap blocks to the metadata journaling code, we can entirely dispense with the rather strange buffer ref counting scheme and also the requirement to journal the rgrps. The net result of all this is that the ->sd_rindex_spin is left to do exactly one job, and that is to look after the rbtree or rgrps. This patch is designed to be a stepping stone towards using RCU for the rbtree of resource groups, however the reduction in the number of uses of the ->sd_rindex_spin is likely to have benefits for multi-threaded workloads, anyway. The patch retains ->go_lock and ->go_unlock for rgrps, however these maybe also be removed in future in favour of calling the functions directly where required in the code. That will allow locking of resource groups without needing to actually read them in - something that could be useful in speeding up statfs. In the mean time though it is valid to dereference ->bi_bh only when the rgrp is locked. This is basically the same rule as before, modulo the references not being valid until the following journal flush. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Cc: Benjamin Marzinski <bmarzins@redhat.com>
* GFS2: Fix bug trap and journaled data fsyncSteven Whitehouse2011-10-211-4/+4
| | | | | | | | | | | | | | | Journaled data requires that a complete flush of all dirty data for the file is done, in order that the ail flush which comes after will succeed. Also the recently enhanced bug trap can trigger falsely in case an ail flush from fsync races with a page read. This updates the bug trap such that it will ignore buffers which are locked and only trigger on dirty and/or pinned buffers when the ail flush is run from fsync. The original bug trap is retained when ail flush is run from ->go_sync() Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Fix bug-trap in ail flush codeSteven Whitehouse2011-10-211-4/+19
| | | | | | | | | | | | The assert was being tested under the wrong lock, a legacy of the original code. Also, if it does trigger, the resulting information was not always a lot of help. This moves the patch under the correct lock and also prints out more useful information in tacking down the source of the problem. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Add S_NOSEC supportSteven Whitehouse2011-07-151-1/+2
| | | | | | | | | | | This adds S_NOSEC support to GFS2. We set/reset the flag either when a user calls setattr or when we have just regained the glock from another node. The flag is only set if there are no xattrs on the inode and there is no suid bit set. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
* GFS2: Automatically adjust glock min hold timeBob Peterson2011-07-151-2/+0
| | | | | | | | 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>
* GFS2: Cache dir hash table in a contiguous bufferSteven Whitehouse2011-07-151-0/+2
| | | | | | | | | | | | | | | | | | This patch adds a cache for the hash table to the directory code in order to help simplify the way in which the hash table is accessed. This is intended to be a first step towards introducing some performance improvements in the directory code. There are two follow ups that I'm hoping to see fairly shortly. One is to simplify the hash table reading code now that we always read the complete hash table, whether we want one entry or all of them. The other is to introduce readahead on the heads of the hash chains which are referred to from the table. The hash table is a maximum of 128k in size, so it is not worth trying to read it in small chunks. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Resolve inode eviction and ail list interaction bugSteven Whitehouse2011-07-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch contains a few misc fixes which resolve a recently reported issue. This patch has been a real team effort and has received a lot of testing. The first issue is that the ail lock needs to be held over a few more operations. The lock thats added into gfs2_releasepage() may possibly be a candidate for replacing with RCU at some future point, but at this stage we've gone for the obvious fix. The second issue is that gfs2_write_inode() can end up calling a glock recursively when called from gfs2_evict_inode() via the syncing code, so it needs a guard added. The third issue is that we either need to not truncate the metadata pages of inodes which have zero link count, but which we cannot deallocate due to them still being in use by other nodes, or we need to ensure that those pages have all made it through the journal and ail lists first. This patch takes the former approach, but the latter has also been tested and there is nothing to choose between them performance-wise. So again, we could revise that decision in the future. Also, the inode eviction process is now better documented. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Tested-by: Bob Peterson <rpeterso@redhat.com> Tested-by: Abhijith Das <adas@redhat.com> Reported-by: Barry J. Marson <bmarson@redhat.com> Reported-by: David Teigland <teigland@redhat.com>
* GFS2: force a log flush when invalidating the rindex glockBenjamin Marzinski2011-07-121-1/+3
| | | | | | | | | | | | | | | | | | Right now, there is nothing that forces the log to get flushed when a node drops its rindex glock so that another node can grow the filesystem. If the log doesn't get flushed, GFS2 can corrupt the sd_log_le_rg list in the following way. A node puts an rgd on the list in rg_lo_add(), and then the rindex glock is dropped so the other node can grow the filesystem. When the node reacquires the rindex glock, that rgd gets deleted in clear_rgrpdi() before ever being removed from the list by gfs2_log_flush(). This code simply forces a log flush when the rindex glock is invalidated, solving the problem. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Move gfs2_refresh_inode() and friends into glops.cSteven Whitehouse2011-05-091-0/+113
| | | | | | | Eventually there will only be a single caller of this code, so lets move it where it can be made static at some future date. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Clean up fsync()Steven Whitehouse2011-04-201-17/+42
| | | | | | | | | | | This patch is designed to clean up GFS2's fsync implementation and ensure that it really does get everything on disk. Since ->write_inode() has been updated, we can call that via the vfs library function sync_inode_metadata() and the only remaining thing that has to be done is to ensure that we get any revoke records in the log after the inode has been written back. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Don't try to deallocate unlinked inodes when mounted roSteven Whitehouse2011-04-181-0/+4
| | | | | | | | This adds a couple of missing tests to avoid read-only nodes from attempting to deallocate unlinked inodes. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Reported-by: Michel Andre de la Porte <madelaporte@ubi.com>
* GFS2: introduce AIL lockDave Chinner2011-03-111-2/+8
| | | | | | | | | | | | | | | | | | | The log lock is currently used to protect the AIL lists and the movements of buffers into and out of them. The lists are self contained and no log specific items outside the lists are accessed when starting or emptying the AIL lists. Hence the operation of the AIL does not require the protection of the log lock so split them out into a new AIL specific lock to reduce the amount of traffic on the log lock. This will also reduce the amount of serialisation that occurs when the gfs2_logd pushes on the AIL to move it forward. This reduces the impact of log pushing on sequential write throughput. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Use RCU for glock hash tableSteven Whitehouse2011-01-211-14/+9
| | | | | | | | | | | | | | | | | | | 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>
* GFS2: Don't flush delete workqueue when releasing the transaction lockSteven Whitehouse2010-12-161-1/+0
| | | | | | | | | | | | | | | | There is no requirement to flush the delete workqueue before a gfs2 filesystem is suspended. The workqueue's work will just be suspended along with the rest of the tasks on the filesystem. The resolves a deadlock situation where the transaction lock's demotion code was trying to flush the delete workqueue while at the same time, the workqueue was waiting for the transaction lock. The delete workqueue is flushed by gfs2_make_fs_ro() already, so that umount/remount are correctly protected anyway. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Fix type mapping for demote_rq interfaceSteven Whitehouse2010-10-061-1/+0
| | | | | | | | | Mostly the glock operations follow the type of the glock. The one exception is the transaction glock, so we need to check for that directly. Reported-by: Dr. David Alan Gilbert <linux@treblig.org> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Remove i_disksizeSteven Whitehouse2010-09-201-3/+2
| | | | | | | | | With the update of the truncate code, ip->i_disksize and inode->i_size are merely copies of each other. This means we can remove ip->i_disksize and use inode->i_size exclusively reducing the size of a GFS2 inode by 8 bytes. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* GFS2: Metadata address space clean upSteven Whitehouse2010-03-011-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* GFS2: Use forget_all_cached_acls()Steven Whitehouse2009-12-031-1/+4
| | | | | | Invalidate all the cached ACLs when we drop the glock. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: remove dcache entries for remote deleted inodesBenjamin Marzinski2009-07-301-0/+21
| | | | | | | | | | | | | 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>
* GFS2: Improve resource group error handlingSteven Whitehouse2009-05-201-19/+1
| | | | | | | | | | | | | | | 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>
* GFS2: Clear dirty bit at end of inode glock syncSteven Whitehouse2009-04-201-0/+6
| | | | | | | | 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>
* GFS2: Clean up of glops.cSteven Whitehouse2009-03-241-63/+52
| | | | | | | | | | | | | | | | 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>
* GFS2: Add a "demote a glock" interface to sysfsSteven Whitehouse2009-03-241-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* GFS2: Fix deadlock on journal flushSteven Whitehouse2009-03-241-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* GFS2: Merge lock_dlm module into GFS2Steven Whitehouse2009-03-241-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* GFS2: Kill two daemons with one patchSteven Whitehouse2009-01-051-13/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* GFS2: Fix "truncate in progress" hangSteven Whitehouse2009-01-051-2/+9
| | | | | | | | | | | | | | | | | | | | | | | 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>
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