08 Aug, 2017

3 commits


26 Dec, 2016

2 commits

  • No point in going through loops and hoops instead of just comparing the
    values.

    Signed-off-by: Thomas Gleixner
    Cc: Peter Zijlstra

    Thomas Gleixner
     
  • ktime_set(S,N) was required for the timespec storage type and is still
    useful for situations where a Seconds and Nanoseconds part of a time value
    needs to be converted. For anything where the Seconds argument is 0, this
    is pointless and can be replaced with a simple assignment.

    Signed-off-by: Thomas Gleixner
    Cc: Peter Zijlstra

    Thomas Gleixner
     

20 Nov, 2014

1 commit

  • A process may exit, leaving an orphan lock in the lockspace.
    This adds the capability for another process to acquire the
    orphan lock. Acquiring the orphan just moves the lock from
    the orphan list onto the acquiring process's list of locks.

    An adopting process must specify the resource name and mode
    of the lock it wants to adopt. If a matching lock is found,
    the lock is moved to the caller's 's list of locks, and the
    lkid of the lock is returned like the lkid of a new lock.

    If an orphan with a different mode is found, then -EAGAIN is
    returned. If no orphan lock is found on the resource, then
    -ENOENT is returned. No async completion is used because
    the result is immediately available.

    Also, when orphans are purged, allow a zero nodeid to refer
    to the local nodeid so the caller does not need to look up
    the local nodeid.

    Signed-off-by: David Teigland

    David Teigland
     

15 Feb, 2014

1 commit


13 Feb, 2014

1 commit


27 Jun, 2013

1 commit


28 Feb, 2013

1 commit

  • Convert to the much saner new idr interface. Error return values from
    recover_idr_add() mix -1 and -errno. The conversion doesn't change
    that but it looks iffy.

    Signed-off-by: Tejun Heo
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Tejun Heo
     

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
     

17 Jul, 2012

4 commits

  • I don't know exactly how, but in some cases, a dir
    record is not removed, or a new one is created when
    it shouldn't be. The result is that the dir node
    lookup returns a master node where the rsb does not
    exist. In this case, The master node will repeatedly
    return -EBADR for requests, and the lock requests will
    be stuck.

    Until all possible ways for this to happen can be
    eliminated, a simple and effective way to recover from
    this situation is for the supposed master node to send
    a standard remove message to the dir node when it
    receives a request for a resource it has no rsb for.

    Signed-off-by: David Teigland

    David Teigland
     
  • The process of rebuilding locks on a new master during
    recovery could re-order the locks on the convert queue,
    creating an "in place" conversion deadlock that would
    not be resolved. Fix this by not considering queue
    order when granting conversions after recovery.

    Signed-off-by: David Teigland

    David Teigland
     
  • 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
     
  • 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

3 commits

  • Change some existing error/debug messages to
    collect more useful information, and add
    some new error/debug messages to address
    recently found problems.

    Signed-off-by: David Teigland

    David Teigland
     
  • If the rsb is found in the "keep" tree, but is
    not the right type (i.e. not MASTER), we can
    return immediately with the result. There's
    no point in going on to search the "toss" list
    as if we hadn't found it.

    Signed-off-by: David Teigland

    David Teigland
     
  • An outstanding remote operation (an lkb on the "waiter"
    list) could sometimes miss being resent during recovery.
    The decision was based on the lkb_nodeid field, which
    could have changed during an earlier aborted recovery,
    so it no longer represents the actual remote destination.
    The lkb_wait_nodeid is always the actual remote node,
    so it is the best value to use.

    Signed-off-by: David Teigland

    David Teigland
     

24 Apr, 2012

1 commit


09 Mar, 2012

1 commit


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
     

15 Jul, 2011

1 commit


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

3 commits

  • This is simpler and quicker than the hash table, and
    avoids needing to search the hash list for every new
    lkid to check if it's used.

    Signed-off-by: David Teigland

    David Teigland
     
  • The gfp and size args were switched.

    Signed-off-by: David Teigland

    David Teigland
     
  • In fs/dlm/lock.c in the dlm_scan_waiters() function there are 3 small
    issues:

    1) There's no need to test the return value of the allocation and do a
    memset if is succeedes. Just use kzalloc() to obtain zeroed memory.

    2) Since kfree() handles NULL pointers gracefully, the test of
    'warned' against NULL before the kfree() after the loop is completely
    pointless. Remove it.

    3) The arguments to kmalloc() (now kzalloc()) were swapped. Thanks to
    Dr. David Alan Gilbert for pointing this out.

    Signed-off-by: Jesper Juhl
    Signed-off-by: David Teigland

    Jesper Juhl
     

25 May, 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


31 Mar, 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
     

03 Sep, 2010

1 commit

  • When converting a lock, an lkb is in the granted state and also being used
    to request a new state. In the case that the conversion was a "try 1cb"
    type which has failed, and if the new state was incompatible with the old
    state, a callback was being generated to the requesting node. This is
    incorrect as callbacks should only be sent to all the other nodes holding
    blocking locks. The requesting node should receive the normal (failed)
    response to its "try 1cb" conversion request only.

    This was discovered while debugging a performance problem on GFS2, however
    this fix also speeds up GFS as well. In the GFS2 case the performance gain
    is over 10x for cases of write activity to an inode whose glock is cached
    on another, idle (wrt that glock) node.

    (comment added, dct)

    Signed-off-by: Steven Whitehouse
    Tested-by: Abhijith Das
    Signed-off-by: David Teigland

    Steven Whitehouse
     

01 May, 2010

1 commit

  • Smatch complains because "lkb" is never NULL. Looking at it, the original
    code actually adds the new element to the end of the list fine, so we can
    just get rid of the if condition. This code is four years old and no one
    has complained so it must work.

    Signed-off-by: Dan Carpenter
    Signed-off-by: David Teigland

    Dan Carpenter
     

30 Mar, 2010

1 commit

  • …it 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>

    Tejun Heo
     

27 Feb, 2010

2 commits

  • The bast mode that appears in the debugfs output should be
    useful on both master and process nodes. lkb_highbast is
    currently printed, and is only useful on the master node.
    lkb_bastmode is only useful on the process node. This
    patch sets lkb_bastmode on the master node as well, and
    uses that value in the debugfs print.

    Signed-off-by: David Teigland

    David Teigland
     
  • When the lock master processes a successful operation (request,
    convert, cancel, or unlock), it will process the effects of the
    change before sending the reply for the operation. The "effects"
    of the operation are:

    - blocking callbacks (basts) for any newly granted locks
    - waiting or converting locks that can now be granted

    The cast is queued on the local node when the reply from the lock
    master is received. This means that a lock holder can receive a
    bast for a lock mode that is doesn't yet know has been granted.

    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