Taskfs with one-to-many support

As promised the 123f4c23dd has support for one to many task execution. In simple words, it means that if you mount multiple remote resources, any command issued will be executed on all remote resources with input provided to all of those nodes. The stdio, stderr and status files will provide contents from all remote locations in merged format.

At implementation level, once the resources are reserved, any write command on taskfs resource is repeated on corresponding files on all remote nodes. Similarly reads on taskfs files propagated with data from all remote node files.

Following are two scenarios of one to many taskfs usages.

; cd /task/remote
; cat clone
0;
; cd 0
; cat status
cat: read error: No remote reservation done
; mount -A tcp!127.0.0.1!6666 /remote/host1
; echo res 2 > ctl
; cat status
cmd/0 1 Closed /home/pravin/projects/inferno/ericvh//ericvh-brasil/ ''
cmd/1 1 Closed /home/pravin/projects/inferno/ericvh//ericvh-brasil/ ''
; echo exec pwd > ctl
; cat stdio
/home/pravin/projects/inferno/ericvh/ericvh-brasil
/home/pravin/projects/inferno/ericvh/ericvh-brasil

Above is the first scenario of reserving two remote resources when there is only one remote host is available, namely host1. Request for two resources is satisfied by creating two separate sessions on same remote host. As a result of this, output of pwd command is same on both sessions, which can be seen from contents of stdio.

; cd /task/remote
; cat clone
0;
; cd 0
; mount -A tcp!127.0.0.1!6666 /remote/host1
; mount -A tcp!127.0.0.1!6667 /remote/host2
; echo res 2 > ctl
; cat status
cmd/0 1 Closed /usr/share/lxr/source/inferno//ericvh-brasil/ ''
cmd/2 1 Closed /home/pravin/projects/inferno/ericvh//ericvh-brasil/ ''
; echo exec pwd > ctl
; cat stdio
/usr/share/lxr/source/inferno/ericvh-brasil
/home/pravin/projects/inferno/ericvh/ericvh-brasil
;

In this second scenario, there are two remote nodes. Namely host1 and host2. Reserving two remote resources end put reserving one session on each of this remote node. As a result, the output in stdio shows different result for both nodes.