glusterfs.git/xlators/mgmt/glusterd/src/glusterd-handler.c, branch v3.4.6beta1

glusterd: release big locks while doing mount

2013-09-10T08:21:14+00:00

Else things can deadlock in getspec v/s glusterd_do_mount()

Change-Id: Ie70b43916e495c1c8f93e4ed0836c2fb7b0e1f1d
BUG: 997576
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/5881
Reviewed-by: Krishnan Parthasarathi 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterd: Disable transport before cleaning up rpc object

2013-06-19T04:53:27+00:00

        Backport of http://review.gluster.org/5000

Problem:
rpc_transport object, which is part of rpc_clnt, is destroyed
prematurely. This is because, rpc_transport object is ref'd by socket
layer and rpc layer. These ref's, until the synctask'izing of
operations, were unref'd sequentially in the epoll thread.
With more threads at play, the sequential unref guarantee is off.

Fix:
Shutting down the transport before proceeding with cleaning up of
rpc_clnt object would serialize the unref's on the rpc_transport object
and thus eliminating the race.

Also, we don't store the address of brickinfo in brick's rpc notify
function, to avoid the possibility of referring a freed brickinfo.
Instead we use a string based id to 'reach' the corresponding brickinfo.

Change-Id: If2739e2eeaee1e8b071ab2b6754b7ea0f81cfceb
BUG: 962619
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/5214
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterd: Add a cmd for getting uuid of local node

2013-06-19T03:28:22+00:00

        Backport of http://review.gluster.org/5175 (upstream)
Usage: gluster system:: uuid get

This is needed since we generate uuid of a node in a lazy manner. ie, we
generate a uuid for the node only on the first volume or peer operation,
when the node needs an external identity.  With this command, we can
force[1] the uuid generation, without a volume or peer operation performed.

[1]: Querying for uuid (or uuid get), forces uuid to come into
existence.

Change-Id: I62c8b6754117756aa4d773dd48af4ddeb1a1d878
BUG: 971661
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/5204
Reviewed-by: Jeff Darcy 
Tested-by: Gluster Build System

glusterd: big lock - a coarse-grained locking to prevent races

2013-04-17T12:48:50+00:00

There are primarily three lists that are part of glusterd process,
that are concurrently accessed. Namely, priv->volumes, priv->peers
and volinfo->bricks_list.

Big-lock approach
-----------------
WHAT IS IT?
Big lock is a coarse-grained lock which protects all three
lists, mentioned above, from racy access.

HOW DOES IT WORK?
At any given point in time, glusterd's thread(s) are in execution
_iff_ there is a preceding, inbound network event. Of course, the
sigwaiter thread and timer thread are exceptions.
A network event is an external trigger to glusterd, via the epoll
thread, in the form of POLLIN and POLLERR.
As long as we take the big-lock at all such entry points and yield
it when we are done, we are guaranteed that all the network events,
accessing the global lists, are serialised.

This amounts to holding the big lock at
- all the handlers of all the actors in glusterd. (POLLIN)
- all the cbks in glusterd. (POLLIN)
- rpc_notify (DISCONNECT event), if we access/modify
  one of the three lists. (POLLERR)

In the case of synctask'ized volume operations, we must remember that,
if we held the big lock for the entire duration of the handler,
we may block other non-synctask rpc actors from executing.
For eg, volume-start would block in PMAP SIGNIN, if done incorrectly.
To prevent this, we need to yield the big lock, when we yield the
synctask, and reacquire on waking up of the synctask.

BUG: 948686
Change-Id: I429832f1fed67bcac0813403d58346558a403ce9
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/4835
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterd: allow multiple instances of glusterd on one machine

2013-04-16T11:48:58+00:00

This is needed to support automated testing of cluster-communication
features such as probing and quorum.  In order to use this, you need to
do the following preparatory steps.

* Copy /var/lib/glusterd to another directory for each virtual host

* Ensure that each virtual host has a different UUID in its glusterd.info

Now you can start each copy of glusterd with the following xlator-options.

* management.transport.socket.bind-address=$ip_address

* management.working-directory=$unique_working_directory

You can use 127.x.y.z addresses for binding without needing to assign
them to interfaces explicitly.  Note that you must use addresses, not
names, because of some stuff in the socket code that's not worth fixing
just for this usage, but after that you can use names in /etc/hosts
instead.

At this point you can issue CLI commands to a specific glusterd using
the --remote-host option.  So far probe, volume create/start/stop,
mount, and basic I/O all seem to work as expected with multiple
instances.

Change-Id: I1beabb44cff8763d2774bc208b2ffcda27c1a550
BUG: 913555
Original-author: Jeff Darcy 
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/4838
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

Do not call xdr_string() with a NULL error message

2013-03-06T05:04:09+00:00

It is illegal to call xdr_string() with a NULL string. Linux
just retruns false, NetBSD gets a SIGSEGV when xdr_string()
calls strlen(NULL)

BUG: 916439
Change-Id: Ia958470ada6e8e55a86d439922ec942d038f5f13
Original-author: Emmanuel Dreyfus 
Signed-off-by: Emmanuel Dreyfus 
Signed-off-by: Jeff Darcy 
Reviewed-on: http://review.gluster.org/4629

glusterd: Making volume-reset use synctask framework

2013-02-09T03:05:50+00:00

Signed-off-by: Avra Sengupta 
Change-Id: Ib25c8fa69d84b8132505ae3f1e67cf88d3f6f9ec
BUG: 852147
Reviewed-on: http://review.gluster.org/4474
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

glusterd : Made volume-set use synctask framework.

2013-02-09T03:04:33+00:00

Change-Id: I1aa08ca843b87839180f9097bca370270a856e6d
BUG: 852147
Signed-off-by: Avra Sengupta 
Reviewed-on: http://review.gluster.org/4488
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

glusterd: Made volume-sync use synctask framework.

2013-02-08T22:21:13+00:00

Change-Id: I048aac2af4d9da9ed541d3756fefefbb2a29198e
BUG: 852147
Signed-off-by: Avra Sengupta 
Reviewed-on: http://review.gluster.org/4489
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

glusterd : Made volume clear-locks use synctask framework.

2013-02-08T22:08:22+00:00

Change-Id: Ia1fe3d0500d999c1f95b43c9e53947834e39d680
BUG: 852147
Signed-off-by: Avra Sengupta 
Reviewed-on: http://review.gluster.org/4490
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati