linux-toradex.git/fs/dlm/lock.c, branch v4.0.6

dlm: adopt orphan locks

2014-11-19T20:48:02+00:00

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

dlm: use INFO for recovery messages

2014-02-14T17:54:44+00:00

The log messages relating to the progress of recovery
are minimal and very often useful.  Change these to
the KERN_INFO level so they are always available.

Signed-off-by: David Teigland

dlm: silence a harmless use after free warning

2014-02-12T21:44:03+00:00

We pass the freed "r" pointer back to the caller.  It's harmless but it
upsets the static checkers.

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

dlm: Avoid LVB truncation

2013-06-26T16:38:02+00:00

For lockspaces with an LVB length above 64 bytes, avoid truncating
the LVB while exchanging it with another node in the cluster.

Signed-off-by: Bart Van Assche 
Signed-off-by: David Teigland

dlm: convert to idr_alloc()

2013-02-28T03:10:19+00:00

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

dlm: avoid scanning unchanged toss lists

2013-01-07T18:02:49+00:00

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

dlm: fix lvb invalidation conditions

2012-11-16T17:20:42+00:00

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

dlm: fix missing dir remove

2012-07-16T19:24:43+00:00

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

dlm: fix conversion deadlock from recovery

2012-07-16T19:18:22+00:00

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

dlm: fix race between remove and lookup

2012-07-16T19:18:01+00:00

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