doc/txt/dafs-fsa.dot

   1 #
   2 # This is a dot (http://www.graphviz.org) description of the various
   3 # states volumes can be in for DAFS (Demand Attach File Server).
   4 #
   5 # Author: Steven Jenkins
   6 # Date: 2007-05-24
   7 #
   8
   9 digraph VolumeStates {
  10         size="11,17"
  11         graph [
  12                 rankdir = "TB"
  13         ];
  14
  15         subgraph clusterKey {
  16                 rankdir="LR";
  17                 shape = "rectangle";
  18
  19         s1 [ shape=plaintext, label = "VPut after VDetach in brown",
  20                         fontcolor="brown" ];
  21         s2 [ shape=plaintext, label = "VAttach in blue",
  22                         fontcolor="blue" ];
  23         s3 [ shape=plaintext, label = "VGet/VHold in purple",
  24                         fontcolor="purple" ];
  25         s4 [ shape=plaintext, label = "Error States in red",
  26                         fontcolor="red" ];
  27         s5 [ shape=plaintext, label = "VPut after VOffline in green",
  28                         fontcolor="green" ];
  29         s6 [ shape=ellipse, label = "re-entrant" ];
  30         s7 [ shape=ellipse, peripheries=2, label="non re-entrant" ];
  31         s8 [ shape=ellipse, color="red", label="Error States" ];
  32
  33         s6->s7->s8->s1->s2->s3->s4->s5 [style="invis"];
  34
  35         }
  36
  37         node [ peripheries = "2" ] ATTACHING \
  38                 LOADING_VNODE_BITMAPS HDR_LOADING_FROM_DISK \
  39                 HDR_ATTACHING_LRU_PULL \
  40                 "UPDATING\nSYNCING_VOL_HDR_TO_DISK" \
  41                 OFFLINING DETACHING;
  42         node [ shape = "ellipse", peripheries = "1" ];
  43         node [ color = "red" ] HARD_ERROR SALVAGE_REQUESTED SALVAGING;
  44
  45         node [ color = "black" ]; // default back to black
  46
  47         UNATTACHED->Exclusive_vol_op_executing [label = "controlled by FSSYNC" ];
  48         Exclusive_vol_op_executing->UNATTACHED  [label = "controlled by FSSYNC" ];
  49         UNATTACHED->FREED [ label = "VCancelReservation_r() after a\nVDetach() or FreeVolume() will\ncause CheckDetach() or CheckFree() to fire" ];
  50         OFFLINING->UNATTACHED;
  51         UNATTACHED->PREATTACHED [ color = "orange", label = "PreAttach()" ];
  52         PREATTACHED->UNATTACHED [ color = "orange", label = "VOffline()"];
  53         HARD_ERROR->PREATTACHED [ color = "orange", label = "operator intervention via FSSYNC" ];
  54
  55         PREATTACHED->Exclusive_vol_op_executing [color = "orange", label = "controlled by FSSYNC" ];
  56         Exclusive_vol_op_executing->PREATTACHED [color = "orange", label = "controlled by FSSYNC" ];
  57         PREATTACHED->FREED [ color = "orange", label = "VCancelReservation_r() after a\nVDetach() or FreeVolume() will\ncause CheckDetach() or CheckFree() to fire" ];
  58         PREATTACHED->ATTACHING [ color = "blue", weight = "8" ];
  59         SALVAGING->PREATTACHED [ label = "controlled via FSSYNC" ];
  60
  61         DETACHING->FREED ;
  62         SHUTTING_DOWN->DETACHING [ color = "brown" ];
  63         ATTACHED_nUsers_GT_0->SHUTTING_DOWN [ color = "orange", label = "VDetach()" ];
  64
  65         DETACHING->"UPDATING\nSYNCING_VOL_HDR_TO_DISK" [ color = "brown" ];
  66         "UPDATING\nSYNCING_VOL_HDR_TO_DISK"->DETACHING [ color = "brown" ];
  67         OFFLINING->"UPDATING\nSYNCING_VOL_HDR_TO_DISK" [ color = "green" ];
  68         "UPDATING\nSYNCING_VOL_HDR_TO_DISK"->OFFLINING [ color = "green" ];
  69         GOING_OFFLINE->OFFLINING [ color = "green" ];
  70
  71         "UPDATING\nSYNCING_VOL_HDR_TO_DISK"->SALVAGE_REQUESTED [ color = "red" ];
  72         "UPDATING\nSYNCING_VOL_HDR_TO_DISK"->ATTACHING [ color = "blue" ];
  73         ATTACHING->"UPDATING\nSYNCING_VOL_HDR_TO_DISK" [ color = "blue" ];
  74
  75         ATTACHED_nUsers_GT_0->GOING_OFFLINE [ color = "orange", label = "VOffline" ];
  76         ATTACHED_nUsers_GT_0->ATTACHED_nUsers_EQ_0 [ color = "orange", label = "VPut" ];
  77
  78         ATTACHED_nUsers_GT_0->SALVAGE_REQUESTED [ color = "red" ];
  79
  80         LOADING_VNODE_BITMAPS->ATTACHING [ color = "blue" ];
  81         ATTACHING->LOADING_VNODE_BITMAPS [ color = "blue" ] ;
  82         LOADING_VNODE_BITMAPS->SALVAGE_REQUESTED [ color = "red" ];
  83         HDR_LOADING_FROM_DISK->SALVAGE_REQUESTED [ color = "red" ];
  84         HDR_LOADING_FROM_DISK->ATTACHING [ color = "blue" ] ;
  85         HDR_LOADING_FROM_DISK->ATTACHED_nUsers_GT_0 [ color = "purple" ];
  86
  87         SALVAGE_REQUESTED->SALVAGING [ label = "controlled via FSSYNC" ];
  88         SALVAGE_REQUESTED->HARD_ERROR [ color = "red",
  89                 label = "After hard salvage limit reached,\n hard error state is in effect\nuntil there is operator intervention" ];
  90
  91         HDR_ATTACHING_LRU_PULL->HDR_LOADING_FROM_DISK [ color = "blue" ];
  92         HDR_ATTACHING_LRU_PULL->HDR_LOADING_FROM_DISK [ color = "purple" ];
  93         HDR_ATTACHING_LRU_PULL->ATTACHED_nUsers_GT_0 [ color = "purple", label = "header can be in LRU\nand not have been reclaimed\nthus skipping disk I/O" ];
  94
  95         ATTACHING->HDR_ATTACHING_LRU_PULL [ color = "blue" ];
  96         ATTACHING->ATTACHED_nUsers_EQ_0 [ color = "blue" ];
  97
  98         ATTACHING->SALVAGE_REQUESTED [ color = "red" ];
  99         ATTACHED_nUsers_EQ_0->HDR_ATTACHING_LRU_PULL [ color = "purple" ];
 100
 101         ATTACHED_nUsers_EQ_0->SALVAGE_REQUESTED [ color = "red" ];
 102
 103         // Various loopback transitions
 104         GOING_OFFLINE->GOING_OFFLINE [ label = "VPut when (nUsers > 1)" ];
 105         SHUTTING_DOWN->SHUTTING_DOWN
 106                 [ label = "VPut when ((nUsers > 1) ||\n((nUsers == 1) && (nWaiters > 0)))" ];
 107         SHUTTING_DOWN->SHUTTING_DOWN
 108                 [ label = "VCancelReservation_r when ((nWaiters > 1)\n|| ((nWaiters == 1) && (nUsers > 0)))"];
 109 }