Merge PR #679 (fixes branch from @eugeneia) into next

src/core/shm.lua

@@ -103,10 +103,15 @@ end
 -- Make directories needed for a named object.
 -- Given the name "foo/bar/baz" create /var/run/foo and /var/run/foo/bar.
 function mkdir (name)
-   -- Create root with mode "rwxrwxrwt" (R/W for all and sticky)
-   local mask = S.umask(0)
-   S.mkdir(root, "01777")
-   S.umask(mask)
+   -- Create root with mode "rwxrwxrwt" (R/W for all and sticky) if it
+   -- does not exist yet.
+   if not S.stat(root) then
+      local mask = S.umask(0)
+      local status, err = S.mkdir(root, "01777")
+      assert(status, ("Unable to create %s: %s"):format(
+                root, tostring(err or "unspecified error")))
+      S.umask(mask)
+   end
    -- Create sub directories
    local dir = root
    name:gsub("([^/]+)",

src/lib/hardware/pci.lua

@@ -2,6 +2,7 @@ module(...,package.seeall)
 
 local ffi = require("ffi")
 local C = ffi.C
+local S = require("syscall")
 
 local lib = require("core.lib")
 
@@ -34,6 +35,7 @@ end
 function device_info (pciaddress)
    local info = {}
    local p = path(pciaddress)
+   assert(S.stat(p), ("No such device: %s"):format(pciaddress))
    info.pciaddress = canonical(pciaddress)
    info.vendor = lib.firstline(p.."/vendor")
    info.device = lib.firstline(p.."/device")

src/program/packetblaster/packetblaster.lua

@@ -46,6 +46,7 @@ function run (args)
          config.link(c, "tee."..tostring(nics).."->"..name..".input")
       end
    end
+   assert(nics > 0, "<PCI> matches no suitable devices.")
    engine.busywait = true
    intel10g.num_descriptors = 32*1024
    engine.configure(c)

src/program/snabbnfv/traffic/traffic.lua

@@ -78,6 +78,9 @@ function long_usage () return usage end
 function traffic (pciaddr, confpath, sockpath)
    engine.log = true
    local mtime = 0
+   if C.stat_mtime(confpath) == 0 then
+      print(("WARNING: File '%s' does not exist."):format(confpath))
+   end
    while true do
       local mtime2 = C.stat_mtime(confpath)
       if mtime2 ~= mtime then