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* GFS2: high time to take some time over atimeSteven Whitehouse2008-09-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [GFS2] Remove remote lock dropping codeSteven Whitehouse2008-06-27
| | | | | | | | | | | | | | | | | | | 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>
* [GFS2] Clean up the glock coreSteven Whitehouse2008-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [GFS2] Fix a page lock / glock deadlockSteven Whitehouse2008-03-31
| | | | | | | | | | | | | | | | | | 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>
* [GFS2] make gfs2_glock_hold() staticAdrian Bunk2008-03-31
| | | | | | | gfs2_glock_hold() can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* gfs2: make gfs2_holder.gh_owner_pid be a struct pid *Pavel Emelyanov2008-02-07
| | | | | | | | | | | | 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>
* [GFS2] flocks from same process trip kernel BUG at fs/gfs2/glock.c:1118!Abhijith Das2007-10-10
| | | | | | | | | | | | | | | | 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>
* [GFS2] Reduce number of gfs2_scand processes to oneSteven Whitehouse2007-10-10
| | | | | | | | | 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>
* [GFS2] Fix deallocation issuesAbhijith Das2007-07-09
| | | | | | | | | | | | | | | | | | | | | 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>
* Detach sched.h from mm.hAlexey Dobriyan2007-05-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [GFS2] Red Hat bz 228540: owner referencesRobert Peterson2007-05-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [GFS2] Fix bz 224480 and cleanup glock demotion codeSteven Whitehouse2007-05-01
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* [GFS2] Add gfs2_tool lockdump support to gfs2 (bz 228540)Robert Peterson2007-05-01
| | | | | | | | | | | | | | | The attached patch resolves bz 228540. This adds the capability for gfs2 to dump gfs2 locks through the debugfs file system. This used to exist in gfs1 as "gfs_tool lockdump" but it's missing from gfs2 because all the ioctls were stripped out. Please see the bugzilla for more history about the fix. This patch is also attached to the bugzilla record. The patch is against Steve Whitehouse's latest nmw git tree kernel (2.6.21-rc1) and has been tested on system trin-10. Signed-off-by: Robert Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Tidy up glops callsSteven Whitehouse2007-02-05
| | | | | | | | | | | | | | | | | | | This patch doesn't make any changes to the ordering of the various operations related to glocking, but it does tidy up the calls to the glops.c functions to make the structure more obvious. The two functions: gfs2_glock_xmote_th() and gfs2_glock_drop_th() can be made static within glock.c since they are called by every set of glock operations. The xmote_th and drop_th glock operations are then made conditional upon those two routines existing and called from the previously mentioned functions in glock.c respectively. Also it can be seen that the go_sync operation isn't needed since it can easily be replaced by calls to xmote_bh and drop_bh respectively. This results in no longer (confusingly) calling back into routines in glock.c from glops.c and also reducing the glock operations by one member. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Remove local exclusive glock modeSteven Whitehouse2007-02-05
| | | | | | | | | | | | | | | Here is a patch for GFS2 to remove the local exclusive flag. In the places it was used, mutex's are always held earlier in the call path, so it appears redundant in the LM_ST_SHARED case. Also, the GFS2 holders were setting local exclusive in any case where the requested lock was LM_ST_EXCLUSIVE. So the other places in the glock code where the flag was tested have been replaced with tests for the lock state being LM_ST_EXCLUSIVE in order to ensure the logic is the same as before (i.e. LM_ST_EXCLUSIVE is always locally exclusive as well as globally exclusive). Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Remove the "greedy" function from glock.[ch]Steven Whitehouse2007-02-05
| | | | | | | | | | | | | | | The "greedy" code was an attempt to retain glocks for a minimum length of time when they relate to mmap()ed files. The current implementation of this feature is not, however, ideal in that it required allocating memory in order to do this and its overly complicated. It also misses the mark by ignoring the other I/O operations which are just as likely to suffer from the same problem. So the plan is to remove this now and then add the functionality back as part of the glock state machine at a later date (and thus take into account all the possible users of this feature) Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Clean up/speed up readdirSteven Whitehouse2007-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This removes the extra filldir callback which gfs2 was using to enclose an attempt at readahead for inodes during readdir. The code was too complicated and also hurts performance badly in the case that the getdents64/readdir call isn't being followed by stat() and it wasn't even getting it right all the time when it was. As a result, on my test box an "ls" of a directory containing 250000 files fell from about 7mins (freshly mounted, so nothing cached) to between about 15 to 25 seconds. When the directory content was cached, the time taken fell from about 3mins to about 4 or 5 seconds. Interestingly in the cached case, running "ls -l" once reduced the time taken for subsequent runs of "ls" to about 6 secs even without this patch. Now it turns out that there was a special case of glocks being used for prefetching the metadata, but because of the timeouts for these locks (set to 10 secs) the metadata was being timed out before it was being used and this the prefetch code was constantly trying to prefetch the same data over and over. Calling "ls -l" meant that the inodes were brought into memory and once the inodes are cached, the glocks are not disposed of until the inodes are pushed out of the cache, thus extending the lifetime of the glocks, and thus bringing down the time for subsequent runs of "ls" considerably. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Fix journal flush problemSteven Whitehouse2006-11-30
| | | | | | | | | | | | | | | | | | | | This fixes a bug which resulted in poor performance due to flushing the journal too often. The code path in question was via the inode_go_sync() function in glops.c. The solution is not to flush the journal immediately when inodes are ejected from memory, but batch up the work for glockd to deal with later on. This means that glocks may now live on beyond the end of the lifetime of their inodes (but not very much longer in the normal case). Also fixed in this patch is a bug (which was hidden by the bug mentioned above) in calculation of the number of free journal blocks. The gfs2_logd process has been altered to be more responsive to the journal filling up. We now wake it up when the number of uncommitted journal blocks has reached the threshold level rather than trying to flush directly at the end of each transaction. This again means doing fewer, but larger, log flushes in general. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Fix page lock/glock deadlockSteven Whitehouse2006-11-30
| | | | | | | | | | | | This fixes a race between the glock and the page lock encountered during truncate in gfs2_readpage and gfs2_prepare_write. The gfs2_readpages function doesn't need the same fix since it only uses a try lock anyway, so it will fail back to gfs2_readpage in the case of a potential deadlock. This bug was spotted by Russell Cattelan. Cc: Russell Cattelan <cattelan@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Remove unused GL_DUMP flagSteven Whitehouse2006-11-30
| | | | | | | | There is no way to set the GL_DUMP flag, and in any case the same thing can be done with systemtap if required for debugging, so this removes it. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Remove unused function from glock.cSteven Whitehouse2006-09-09
| | | | | | | The callback for iopen locks is unused, so this removes it. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Use void * instead of typedef for locking module interfaceSteven Whitehouse2006-09-08
| | | | | | | | | | | As requested by Jan Engelhardt, this removes the typedefs in the locking module interface and replaces them with void *. Also since we are changing the interface, I've added a few consts as well. Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Cc: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Remove one typedefSteven Whitehouse2006-09-07
| | | | | | | | | | | This removes one of the typedefs from the locking interface. It is replaced by a forward declaration of the gfs2 superblock. The other two are not so easy to solve since in their case, they can refer to one of two possible structures. Cc: David Teigland <teigland@redhat.com> Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Move glock hash table out of superblockSteven Whitehouse2006-09-07
| | | | | | | | | | | | | | There are several reasons why we want to do this: - Firstly its large and thus we'll scale better with multiple GFS2 fs mounted at the same time - Secondly its easier to scale its size as required (thats a plan for later patches) - Thirdly, we can use kzalloc rather than vmalloc when allocating the superblock (its now only 4888 bytes) - Fourth its all part of my plan to eventually be able to use RCU with the glock hash. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Make headers compile on their ownSteven Whitehouse2006-09-05
| | | | | | | | | As per Jan Engelhardt's comments, this should make all the headers compile on their own by including and/or declaring structures early. Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Change all types to uX styleSteven Whitehouse2006-09-04
| | | | | | | This makes all fixed size types have consistent names. Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Tidy up locking codeSteven Whitehouse2006-09-04
| | | | | | | | As per Jan Engelhardt's second email, this removes some unused code, and fixes up indenting in various places. Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Update copyright, tidy up incore.hSteven Whitehouse2006-09-01
| | | | | | | | | | | | | | | | | | | | | | | As per comments from Jan Engelhardt <jengelh@linux01.gwdg.de> this updates the copyright message to say "version" in full rather than "v.2". Also incore.h has been updated to remove forward structure declarations which are not required. The gfs2_quota_lvb structure has now had endianess annotations added to it. Also quota.c has been updated so that we now store the lvb data locally in endian independant format to avoid needing a structure in host endianess too. As a result the endianess conversions are done as required at various points and thus the conversion routines in lvb.[ch] are no longer required. I've moved the one remaining constant in lvb.h thats used into lm.h and removed the unused lvb.[ch]. I have not changed the HIF_ constants. That is left to a later patch which I hope will unify the gh_flags and gh_iflags fields of the struct gfs2_holder. Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Remove unused code from glock layerSteven Whitehouse2006-08-30
| | | | | | | | Remove the unused sync feature from glocks. This is currently done by calling the required functions to sync pages/blocks directly so this code isn't needed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Make glock operations constSteven Whitehouse2006-08-30
| | | | | | | For all the usual reasons of enforcing correctness and potentially reducing code size, this patch makes the glock operations const. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Fix unlinked file handlingSteven Whitehouse2006-06-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the way we have been dealing with unlinked, but still open files. It removes all limits (other than memory for inodes, as per every other filesystem) on numbers of these which we can support on GFS2. It also means that (like other fs) its the responsibility of the last process to close the file to deallocate the storage, rather than the person who did the unlinking. Note that with GFS2, those two events might take place on different nodes. Also there are a number of other changes: o We use the Linux inode subsystem as it was intended to be used, wrt allocating GFS2 inodes o The Linux inode cache is now the point which we use for local enforcement of only holding one copy of the inode in core at once (previous to this we used the glock layer). o We no longer use the unlinked "special" file. We just ignore it completely. This makes unlinking more efficient. o We now use the 4th block allocation state. The previously unused state is used to track unlinked but still open inodes. o gfs2_inoded is no longer needed o Several fields are now no longer needed (and removed) from the in core struct gfs2_inode o Several fields are no longer needed (and removed) from the in core superblock There are a number of future possible optimisations and clean ups which have been made possible by this patch. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] glock debugging and inode cache changesSteven Whitehouse2006-05-18
| | | | | | | | | | | | | | | This adds some extra debugging to glock.c and changes inode.c's deallocation code to call the debugging code at a suitable moment. I'm chasing down a particular bug to do with deallocation at the moment and the code can go again once the bug is fixed. Also this includes the first part of some changes to unify the Linux struct inode and GFS2's struct gfs2_inode. This transformation will happen in small parts over the next short period. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Update copyright date to 2006Steven Whitehouse2006-05-18
| | | | Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] [-mm patch] fs/gfs2/: possible cleanupsAdrian Bunk2006-04-28
| | | | | | | | | | | | This patch contains the following possible cleanups: - make needlessly global code static - #if 0 unused functions - remove the following global function that was both unused and unimplemented: - super.c: gfs2_do_upgrade() Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Remove GL_NEVER_RECURSE flagSteven Whitehouse2006-04-26
| | | | | | | There is no point in keeping this flag since recursion is not now allowed for any glock. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Fix a bug: scheduling under a spinlockSteven Whitehouse2006-04-20
| | | | | | | | | At some stage, a mutex was added to gfs2_glock_put() without checking all its call sites. Two of them were called from under a spinlock causing random delays at various points and crashes. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Use vmalloc() in dir codeSteven Whitehouse2006-04-18
| | | | | | | | | | | | When allocating memory to sort directory entries, use vmalloc() rather than kmalloc() since for larger directories, the required size can easily be graeter than the 128k maximum of kmalloc(). Also adding the first steps towards getting the AOP_TRUNCATED_PAGE return code get in the glock code by flagging all places where we request a glock and we are holding a page lock. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] Update debugging codeSteven Whitehouse2006-03-29
| | | | | | | | | | | | Update the debugging code in trans.c and at the same time improve the debugging code for gfs2_holders. The new code should be pretty fast during the normal case and provide just as much information in case of errors (or more). One small function from glock.c has moved to glock.h as a static inline so that its return address won't get in the way of the debugging. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* [GFS2] The core of GFS2David Teigland2006-01-16
This patch contains all the core files for GFS2. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>