glusterfs.git/xlators/mgmt/glusterd/src/glusterd-syncop.c, branch v3.4.2

glusterd: Refresh glusterd-syncop fixes from master

2013-05-17T03:44:44+00:00

Following commits were cherry-picked from master,
044f8ce syncop: Remove task from synclock's waitq before 'wake'
cb6aeed glusterd: Give up big lock before performing any RPC
46572fe Revert "glusterd: Fix spurious wakeups in glusterd syncops"
5021e04 synctask: implement barriers around yield, not the other way
4843937 glusterd: Syncop callbks should take big lock too

Change-Id: I5ae71ab98f9a336dc9bbf0e7b2ec50a6ed42b0f5
BUG: 948686
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/4938
Reviewed-by: Amar Tumballi 
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati 
Reviewed-on: http://review.gluster.org/5021
Reviewed-by: Vijay Bellur

glusterd: Perform NULL check on rsp.op_errstr before using it

2013-05-16T15:28:33+00:00

Change-Id: I2ae30f08965b26a21db541f87de78772cb17135a
BUG: 962362
Signed-off-by: Krutika Dhananjay 
Reviewed-on: http://review.gluster.org/4996
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterd: Fix uuid to hostname conversion for 'volume status'

2013-05-14T11:12:50+00:00

BUG: 927648
Change-Id: Ic016e9d1f090372329a8a2e530dac5fc6ed6c5ae
Signed-off-by: Kaushal M 
Reviewed-on: http://review.gluster.org/4874
Reviewed-by: Krishnan Parthasarathi 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

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: Fixed spurious wakeups in glusterd syncops

2013-04-17T12:46:43+00:00

glusterd syncops perform a barrier_wake whenever rpc_clnt_submit returned -1.
This is based on the wrong assumption that the cbkfn wasn't called.
This would result in one more wakeup than there ought to be.

BUG: 948686
Change-Id: I839fd218a81255fe50c2047d67461d45360e894d
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/4834
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterd: Fixed volume-sync in synctask codepath.

2013-04-12T12:59:05+00:00

Change-Id: I2911d3ac80825310f84c5ba6bd7890e65e1ee219
BUG: 950048
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/4643
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterd: Increasing throughput of synctask based mgmt ops.

2013-03-07T06:06:30+00:00

Change-Id: Ibd963f78707b157fc4c9729aa87206cfd5ecfe81
BUG: 913662
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/4638
Tested-by: Gluster Build System 
Reviewed-by: Jeff Darcy

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

glusterd: do dict unref after sending reply to cli

2013-02-03T20:35:09+00:00

This patch channelizes dict unrefs of dictionaries created from the cli
req during volume ops to one common function - glusterd_to_cli() - which
is guaranteed to be called irrespective of whether the command succeeds
or fails.

This patch also removes extra unrefs at a few places.

Change-Id: Ic8ba7166387b5dfd1f5ae860539e1b7093a94662
BUG: 861044
Signed-off-by: Krutika Dhananjay 
Reviewed-on: http://review.gluster.org/4003
Tested-by: Gluster Build System 
Reviewed-by: Amar Tumballi 
Reviewed-by: Anand Avati

glusterd: Made volume-status use synctask framework

2013-02-03T19:56:18+00:00

Change-Id: Id4062799104e5831467ced65a43bfe377b6163f4
BUG: 852147
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/4297
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati