1. 14 11月, 2012 1 次提交
    • D
      GFS2: skip dlm_unlock calls in unmount · fb6791d1
      David Teigland 提交于
      When unmounting, gfs2 does a full dlm_unlock operation on every
      cached lock.  This can create a very large amount of work and can
      take a long time to complete.  However, the vast majority of these
      dlm unlock operations are unnecessary because after all the unlocks
      are done, gfs2 leaves the dlm lockspace, which automatically clears
      the locks of the leaving node, without unlocking each one individually.
      So, gfs2 can skip explicit dlm unlocks, and use dlm_release_lockspace to
      remove the locks implicitly.  The one exception is when the lock's lvb is
      being used.  In this case, dlm_unlock is called because it may update the
      lvb of the resource.
      Signed-off-by: NDavid Teigland <teigland@redhat.com>
      Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
      fb6791d1
  2. 21 8月, 2012 1 次提交
    • T
      workqueue: deprecate flush[_delayed]_work_sync() · 43829731
      Tejun Heo 提交于
      flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
      and convert all users to flush[_delayed]_work().
      
      If you're cc'd and wondering what's going on: Now all workqueues are
      non-reentrant and the regular flushes guarantee that the work item is
      not pending or running on any CPU on return, so there's no reason to
      use the sync flushes at all and they're going away.
      
      This patch doesn't make any functional difference.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Ian Campbell <ian.campbell@citrix.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Mattia Dongili <malattia@linux.it>
      Cc: Kent Yoder <key@linux.vnet.ibm.com>
      Cc: David Airlie <airlied@linux.ie>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Karsten Keil <isdn@linux-pingi.de>
      Cc: Bryan Wu <bryan.wu@canonical.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Alasdair Kergon <agk@redhat.com>
      Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
      Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: linux-wireless@vger.kernel.org
      Cc: Anton Vorontsov <cbou@mail.ru>
      Cc: Sangbeom Kim <sbkim73@samsung.com>
      Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Eric Van Hensbergen <ericvh@gmail.com>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Petr Vandrovec <petr@vandrovec.name>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Avi Kivity <avi@redhat.com> 
      43829731
  3. 03 5月, 2012 1 次提交
    • D
      dlm: fixes for nodir mode · 4875647a
      David Teigland 提交于
      The "nodir" mode (statically assign master nodes instead
      of using the resource directory) has always been highly
      experimental, and never seriously used.  This commit
      fixes a number of problems, making nodir much more usable.
      
      - Major change to recovery: recover all locks and restart
        all in-progress operations after recovery.  In some
        cases it's not possible to know which in-progess locks
        to recover, so recover all.  (Most require recovery
        in nodir mode anyway since rehashing changes most
        master nodes.)
      
      - Change the way nodir mode is enabled, from a command
        line mount arg passed through gfs2, into a sysfs
        file managed by dlm_controld, consistent with the
        other config settings.
      
      - Allow recovering MSTCPY locks on an rsb that has not
        yet been turned into a master copy.
      
      - Ignore RCOM_LOCK and RCOM_LOCK_REPLY recovery messages
        from a previous, aborted recovery cycle.  Base this
        on the local recovery status not being in the state
        where any nodes should be sending LOCK messages for the
        current recovery cycle.
      
      - Hold rsb lock around dlm_purge_mstcpy_locks() because it
        may run concurrently with dlm_recover_master_copy().
      
      - Maintain highbast on process-copy lkb's (in addition to
        the master as is usual), because the lkb can switch
        back and forth between being a master and being a
        process copy as the master node changes in recovery.
      
      - When recovering MSTCPY locks, flag rsb's that have
        non-empty convert or waiting queues for granting
        at the end of recovery.  (Rename flag from LOCKS_PURGED
        to RECOVER_GRANT and similar for the recovery function,
        because it's not only resources with purged locks
        that need grant a grant attempt.)
      
      - Replace a couple of unnecessary assertion panics with
        error messages.
      Signed-off-by: NDavid Teigland <teigland@redhat.com>
      4875647a
  4. 24 4月, 2012 1 次提交
    • B
      GFS2: Instruct DLM to avoid queue convert slowdown · 4c569a72
      Bob Peterson 提交于
      This patch instructs DLM to prevent an "in place" conversion, where the
      lock just stays on the granted queue, and instead forces the conversion to
      the back of the convert queue. This is done on upward conversions only.
          
      This is useful in cases where, for example, a lock is frequently needed in
      PR on one node, but another node needs it temporarily in EX to update it.
      This may happen, for example, when the rindex is being updated by gfs2_grow.
      The gfs2_grow needs to have the lock in EX, but the other nodes need to
      re-read it to retrieve the updates. The glock is already granted in PR on
      the non-growing nodes, so this prevents them from continually re-granting
      the lock in PR, and forces the EX from gfs2_grow to go through.
      Signed-off-by: NBob Peterson <rpeterso@redhat.com>
      Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
      4c569a72
  5. 29 2月, 2012 1 次提交
    • S
      GFS2: glock statistics gathering · a245769f
      Steven Whitehouse 提交于
      The stats are divided into two sets: those relating to the
      super block and those relating to an individual glock. The
      super block stats are done on a per cpu basis in order to
      try and reduce the overhead of gathering them. They are also
      further divided by glock type.
      
      In the case of both the super block and glock statistics,
      the same information is gathered in each case. The super
      block statistics are used to provide default values for
      most of the glock statistics, so that newly created glocks
      should have, as far as possible, a sensible starting point.
      
      The statistics are divided into three pairs of mean and
      variance, plus two counters. The mean/variance pairs are
      smoothed exponential estimates and the algorithm used is
      one which will be very familiar to those used to calculation
      of round trip times in network code.
      
      The three pairs of mean/variance measure the following
      things:
      
       1. DLM lock time (non-blocking requests)
       2. DLM lock time (blocking requests)
       3. Inter-request time (again to the DLM)
      
      A non-blocking request is one which will complete right
      away, whatever the state of the DLM lock in question. That
      currently means any requests when (a) the current state of
      the lock is exclusive (b) the requested state is either null
      or unlocked or (c) the "try lock" flag is set. A blocking
      request covers all the other lock requests.
      
      There are two counters. The first is there primarily to show
      how many lock requests have been made, and thus how much data
      has gone into the mean/variance calculations. The other counter
      is counting queueing of holders at the top layer of the glock
      code. Hopefully that number will be a lot larger than the number
      of dlm lock requests issued.
      
      So why gather these statistics? There are several reasons
      we'd like to get a better idea of these timings:
      
      1. To be able to better set the glock "min hold time"
      2. To spot performance issues more easily
      3. To improve the algorithm for selecting resource groups for
      allocation (to base it on lock wait time, rather than blindly
      using a "try lock")
      Due to the smoothing action of the updates, a step change in
      some input quantity being sampled will only fully be taken
      into account after 8 samples (or 4 for the variance) and this
      needs to be carefully considered when interpreting the
      results.
      
      Knowing both the time it takes a lock request to complete and
      the average time between lock requests for a glock means we
      can compute the total percentage of the time for which the
      node is able to use a glock vs. time that the rest of the
      cluster has its share. That will be very useful when setting
      the lock min hold time.
      
      The other point to remember is that all times are in
      nanoseconds. Great care has been taken to ensure that we
      measure exactly the quantities that we want, as accurately
      as possible. There are always inaccuracies in any
      measuring system, but I hope this is as accurate as we
      can reasonably make it.
      Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
      a245769f
  6. 11 1月, 2012 1 次提交
  7. 04 1月, 2012 1 次提交
    • D
      dlm: add recovery callbacks · 60f98d18
      David Teigland 提交于
      These new callbacks notify the dlm user about lock recovery.
      GFS2, and possibly others, need to be aware of when the dlm
      will be doing lock recovery for a failed lockspace member.
      
      In the past, this coordination has been done between dlm and
      file system daemons in userspace, which then direct their
      kernel counterparts.  These callbacks allow the same
      coordination directly, and more simply.
      Signed-off-by: NDavid Teigland <teigland@redhat.com>
      60f98d18
  8. 09 3月, 2011 1 次提交
    • S
      GFS2: Fix glock deallocation race · fc0e38da
      Steven Whitehouse 提交于
      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: NSteven Whitehouse <swhiteho@redhat.com>
      fc0e38da
  9. 21 1月, 2011 1 次提交
    • S
      GFS2: Use RCU for glock hash table · bc015cb8
      Steven Whitehouse 提交于
      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: NSteven Whitehouse <swhiteho@redhat.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      bc015cb8
  10. 30 11月, 2010 2 次提交
    • S
      GFS2: Merge glock state fields into a bitfield · 47a25380
      Steven Whitehouse 提交于
      We can only merge the fields into a bitfield if the locking
      rules for them are the same. In this case gl_spin covers all
      of the fields (write side) but a couple of them are used
      with GLF_LOCK as the read side lock, which should be ok
      since we know that the field in question won't be changing
      at the time.
      
      The gl_req setting has to be done earlier (in glock.c) in order
      to place it under gl_spin. The gl_reply setting also has to be
      brought under gl_spin in order to comply with the new rules.
      
      This saves 4*sizeof(unsigned int) per glock.
      Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
      Cc: Bob Peterson <rpeterso@redhat.com>
      47a25380
    • S
      GFS2: Clean up of gdlm_lock function · 921169ca
      Steven Whitehouse 提交于
      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: NSteven Whitehouse <swhiteho@redhat.com>
      921169ca
  11. 20 9月, 2010 1 次提交
  12. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking 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: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  13. 01 3月, 2010 1 次提交
    • S
      GFS2: Metadata address space clean up · 009d8518
      Steven Whitehouse 提交于
      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: NSteven Whitehouse <swhiteho@redhat.com>
      009d8518
  14. 03 2月, 2010 2 次提交
  15. 24 3月, 2009 2 次提交
    • B
      GFS2: Fix locking bug in failed shared to exclusive conversion · 02ffad08
      Benjamin Marzinski 提交于
      After calling out to the dlm, GFS2 sets the new state of a glock to
      gl_target in gdlm_ast().  However, gl_target is not always the lock
      state that was requested. If a conversion from shared to exclusive
      fails, finish_xmote() will call do_xmote() with LM_ST_UNLOCKED, instead
      of gl->gl_target, so that it can reacquire the lock in exlusive the next
      time around.  In this case, setting the lock to gl_target in gdlm_ast()
      will make GFS2 think that it has the glock in exclusive mode, when
      really, it doesn't have the glock locked at all.  This patch adds a new
      field to the gfs2_glock structure, gl_req, to track the mode that was
      requested.
      Signed-off-by: NBenjamin Marzinski <bmarzins@redhat.com>
      Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
      02ffad08
    • S
      GFS2: Merge lock_dlm module into GFS2 · f057f6cd
      Steven Whitehouse 提交于
      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: NSteven Whitehouse <swhiteho@redhat.com>
      f057f6cd