15 Feb, 2014

1 commit


08 Jan, 2013

1 commit

  • Keep track of whether a toss list contains any
    shrinkable rsbs. If not, dlm_scand can avoid
    scanning the list for rsbs to shrink. Unnecessary
    scanning can otherwise waste a lot of time because
    the toss lists can contain a large number of rsbs
    that are non-shrinkable (directory records).

    Signed-off-by: David Teigland

    David Teigland
     

17 Nov, 2012

1 commit

  • When a node is removed that held a PW/EX lock, the
    existing master node should invalidate the lvb on the
    resource due to the purged lock.

    Previously, the existing master node was invalidating
    the lvb if it found only NL/CR locks on the resource
    during recovery for the removed node. This could lead
    to cases where it invalidated the lvb and shouldn't
    have, or cases where it should have invalidated and
    didn't.

    When recovery selects a *new* master node for a
    resource, and that new master finds only NL/CR locks
    on the resource after lock recovery, it should
    invalidate the lvb. This case was handled correctly
    (but was incorrectly applied to the existing master
    case also.)

    When a process exits while holding a PW/EX lock,
    the lvb on the resource should be invalidated.
    This was not happening.

    The lvb contents and VALNOTVALID flag should be
    recovered before granting locks in recovery so that
    the recovered lvb state is provided in the callback.
    The lvb was being recovered after the lock was granted.

    Signed-off-by: David Teigland

    David Teigland
     

09 Aug, 2012

1 commit

  • The in_recovery rw_semaphore has always been acquired and
    released by different threads by design. To work around
    the "BUG: bad unlock balance detected!" messages, adjust
    things so the dlm_recoverd thread always does both down_write
    and up_write.

    Signed-off-by: David Teigland

    David Teigland
     

17 Jul, 2012

3 commits

  • It was possible for a remove message on an old
    rsb to be sent after a lookup message on a new
    rsb, where the rsbs were for the same resource
    name. This could lead to a missing directory
    entry for the new rsb.

    It is fixed by keeping a copy of the resource
    name being removed until after the remove has
    been sent. A lookup checks if this in-progress
    remove matches the name it is looking up.

    Signed-off-by: David Teigland

    David Teigland
     
  • When a large number of resources are being recovered,
    a linear search of the recover_list takes a long time.
    Use an idr in place of a list.

    Signed-off-by: David Teigland

    David Teigland
     
  • Remove the dir hash table (dirtbl), and use
    the rsb hash table (rsbtbl) as the resource
    directory. It has always been an unnecessary
    duplication of information.

    This improves efficiency by using a single rsbtbl
    lookup in many cases where both rsbtbl and dirtbl
    lookups were needed previously.

    This eliminates the need to handle cases of rsbtbl
    and dirtbl being out of sync.

    In many cases there will be memory savings because
    the dir hash table no longer exists.

    Signed-off-by: David Teigland

    David Teigland
     

03 May, 2012

1 commit

  • 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: David Teigland

    David Teigland
     

27 Apr, 2012

1 commit


04 Jan, 2012

2 commits

  • 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: David Teigland

    David Teigland
     
  • Slot numbers are assigned to nodes when they join the lockspace.
    The slot number chosen is the minimum unused value starting at 1.
    Once a node is assigned a slot, that slot number will not change
    while the node remains a lockspace member. If the node leaves
    and rejoins it can be assigned a new slot number.

    A new generation number is also added to a lockspace. It is
    set and incremented during each recovery along with the slot
    collection/assignment.

    The slot numbers will be passed to gfs2 which will use them as
    journal id's.

    Signed-off-by: David Teigland

    David Teigland
     

19 Nov, 2011

1 commit

  • Change the linked lists to rb_tree's in the rsb
    hash table to speed up searches. Slow rsb searches
    were having a large impact on gfs2 performance due
    to the large number of dlm locks gfs2 uses.

    Signed-off-by: Bob Peterson
    Signed-off-by: David Teigland

    Bob Peterson
     

16 Jul, 2011

1 commit

  • Instead of creating our own kthread (dlm_astd) to deliver
    callbacks for all lockspaces, use a per-lockspace workqueue
    to deliver the callbacks. This eliminates complications and
    slowdowns from many lockspaces sharing the same thread.

    Signed-off-by: David Teigland

    David Teigland
     

13 Jul, 2011

1 commit

  • By pre-allocating rsb structs before searching the hash
    table, they can be inserted immediately. This avoids
    always having to repeat the search when adding the struct
    to hash list.

    This also adds space to the rsb struct for a max resource
    name, so an rsb allocation can be used by any request.
    The constant size also allows us to finally use a slab
    for the rsb structs.

    Signed-off-by: David Teigland

    David Teigland
     

11 Jul, 2011

1 commit


05 Apr, 2011

1 commit

  • kmalloc a stub message struct during recovery instead of sharing the
    struct in the lockspace. This leaves the lockspace stub_ms only for
    faking downconvert replies, where it is never modified and sharing
    is not a problem.

    Also improve the debug messages in the same recovery function.

    Signed-off-by: David Teigland

    David Teigland
     

02 Apr, 2011

1 commit


11 Mar, 2011

1 commit

  • Change how callbacks are recorded for locks. Previously, information
    about multiple callbacks was combined into a couple of variables that
    indicated what the end result should be. In some situations, we
    could not tell from this combined state what the exact sequence of
    callbacks were, and would end up either delivering the callbacks in
    the wrong order, or suppress redundant callbacks incorrectly. This
    new approach records all the data for each callback, leaving no
    uncertainty about what needs to be delivered.

    Signed-off-by: David Teigland

    David Teigland
     

25 Feb, 2010

1 commit

  • When both blocking and completion callbacks are queued for lock,
    the dlm would always deliver the completion callback (cast) first.
    In some cases the blocking callback (bast) is queued before the
    cast, though, and should be delivered first. This patch keeps
    track of the order in which they were queued and delivers them
    in that order.

    This patch also keeps track of the granted mode in the last cast
    and eliminates the following bast if the bast mode is compatible
    with the preceding cast mode. This happens when a remotely mastered
    lock is demoted, e.g. EX->NL, in which case the local node queues
    a cast immediately after sending the demote message. In this way
    a cast can be queued for a mode, e.g. NL, that makes an in-transit
    bast extraneous.

    Signed-off-by: David Teigland

    David Teigland
     

01 Dec, 2009

1 commit

  • Replace all GFP_KERNEL and ls_allocation with GFP_NOFS.
    ls_allocation would be GFP_KERNEL for userland lockspaces
    and GFP_NOFS for file system lockspaces.

    It was discovered that any lockspaces on the system can
    affect all others by triggering memory reclaim in the
    file system which could in turn call back into the dlm
    to acquire locks, deadlocking dlm threads that were
    shared by all lockspaces, like dlm_recv.

    Signed-off-by: David Teigland

    David Teigland
     

29 Jan, 2009

1 commit


09 Jan, 2009

1 commit


24 Dec, 2008

3 commits

  • The new debugfs entry dumps all rsb and lkb structures, and includes
    a lot more information than has been available before. This includes
    the new timestamps added by a previous patch for debugging callback
    issues.

    Signed-off-by: David Teigland

    David Teigland
     
  • Record the time the latest blocking callback was queued for
    a lock. This will be used for debugging in combination with
    lock queue timestamp changes in the previous patch.

    Signed-off-by: David Teigland

    David Teigland
     
  • Use ktime instead of jiffies for timestamping lkb's. Also stamp the
    time on every lkb whenever it's added to a resource queue, instead of
    just stamping locks subject to timeouts. This will allow us to use
    timestamps more widely for debugging all locks.

    Signed-off-by: David Teigland

    David Teigland
     

29 Aug, 2008

2 commits


23 Apr, 2008

1 commit


22 Apr, 2008

3 commits

  • Add central definitions for max lockspace name length and max resource
    name length. The lack of central definitions has resulted in scattered
    private definitions which we can now clean up, including an unused one
    in dlm_device.h.

    Signed-off-by: David Teigland

    David Teigland
     
  • Move the code that handles cluster posix locks from gfs2 into the dlm
    so that it can be used by both gfs2 and ocfs2.

    Signed-off-by: David Teigland

    David Teigland
     
  • If a node is removed from a lockspace, and then added back before the
    dlm is notified of the removal, the dlm will not detect the removal
    and won't clear the old state from the node. This is fixed by using a
    list of added nodes so the membership recovery can detect when a newly
    added node is already in the member list.

    Signed-off-by: David Teigland

    David Teigland
     

19 Apr, 2008

1 commit


07 Feb, 2008

1 commit


06 Feb, 2008

1 commit


04 Feb, 2008

4 commits


30 Jan, 2008

1 commit


10 Oct, 2007

1 commit

  • Introduce a per-lockspace rwsem that's held in read mode by dlm_recv
    threads while working in the dlm. This allows dlm_recv activity to be
    suspended when the lockspace transitions to, from and between recovery
    cycles.

    The specific bug prompting this change is one where an in-progress
    recovery cycle is aborted by a new recovery cycle. While dlm_recv was
    processing a recovery message, the recovery cycle was aborted and
    dlm_recoverd began cleaning up. dlm_recv decremented recover_locks_count
    on an rsb after dlm_recoverd had reset it to zero. This is fixed by
    suspending dlm_recv (taking write lock on the rwsem) before aborting the
    current recovery.

    The transitions to/from normal and recovery modes are simplified by using
    this new ability to block dlm_recv. The switch from normal to recovery
    mode means dlm_recv goes from processing locking messages, to saving them
    for later, and vice versa. Races are avoided by blocking dlm_recv when
    setting the flag that switches between modes.

    Signed-off-by: David Teigland
    Signed-off-by: Steven Whitehouse

    David Teigland