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).
19 s1 [ shape=plaintext, label = "VAllocVnode",
21 s2 [ shape=plaintext, label = "VGetVnode",
23 s3 [ shape=plaintext, label = "VPutVnode",
25 s4 [ shape=plaintext, label = "Error States",
27 s5 [ shape=plaintext, label = "VVnodeWriteToRead",
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" ];
33 s6->s7->s8->s1->s2->s3->s5->s4 [style="invis"];
37 node [ peripheries = "2" ] \
38 RELEASING ALLOC LOADING EXCLUSIVE STORE ;
39 node [ shape = "ellipse", peripheries = "1" ];
40 node [ color = "red" ] ERROR ;
42 node [ color = "black" ]; // default back to black
46 INVALID [ label = "Vn_state(vnp) == VN_STATE_INVALID\n(vnode cache entry is invalid)" ];
47 RELEASING [ label = "Vn_state(vnp) == VN_STATE_RELEASING\n(vnode is busy releasing its inode handle ref)" ];
48 ALLOC [ label = "Vn_state(vnp) == VN_STATE_ALLOC\n(vnode is busy allocating disk entry)" ];
49 ALLOC_read [ label = "reading stale vnode from disk\nto verify inactive state" ];
50 ALLOC_extend [ label = "extending vnode index file" ];
51 ONLINE [ label = "Vn_state(vnp) == VN_STATE_ONLINE\n(vnode is a valid cache entry)" ];
52 LOADING [ label = "Vn_state(vnp) == VN_STATE_LOAD\n(vnode is busy loading from disk)" ];
53 EXCLUSIVE [ label = "Vn_state(vnp) == VN_STATE_EXCLUSIVE\n(vnode is owned exclusively by an external caller)" ];
54 STORE [ label = "Vn_state(vnp) == VN_STATE_STORE\n(vnode is busy writing to disk)" ];
55 READ [ label = "Vn_state(vnp) == VN_STATE_READ\n(vnode is shared by several external callers)" ];
56 ERROR [ label = "Vn_state(vnp) == VN_STATE_ERROR\n(vnode hard error state)" ];
59 ONLINE->RELEASING [ label = "VGetFreeVnode_r()" ];
60 RELEASING->INVALID [ label = "VGetFreeVnode_r()" ];
62 INVALID->ALLOC [ color="brown", label="vnode not in cache; allocating" ];
63 ONLINE->EXCLUSIVE [ color="brown", label="vnode in cache" ];
64 ALLOC->ALLOC_read [ color="brown", label="vnode index is within present file size" ];
65 ALLOC->ALLOC_extend [ color="brown", label="vnode index is beyond end of file" ];
66 ALLOC_read->EXCLUSIVE [ color="brown" ];
67 ALLOC_extend->EXCLUSIVE [ color="brown" ];
68 ALLOC_read->INVALID [ color="red", label="I/O error; invalidating vnode\nand scheduling salvage" ];
69 ALLOC_extend->INVALID [ color="red", label="I/O error; invalidating vnode\nand scheduling salvage" ];
71 INVALID->LOADING [ color="blue", label="vnode not cached" ];
72 LOADING->INVALID [ color="red", label="I/O error; invalidating vnode\nand scheduling salvage" ];
73 LOADING->ONLINE [ color="blue" ];
74 ONLINE->READ [ color="blue", label="caller requested read lock" ];
75 ONLINE->EXCLUSIVE [ color="blue", label="caller requested write lock" ];
77 EXCLUSIVE->READ [ color="green", label="vnode not changed" ];
78 EXCLUSIVE->STORE [ color="green", label="vnode changed" ];
79 EXCLUSIVE->ONLINE [ color="purple", label="vnode not changed" ];
80 EXCLUSIVE->STORE [ color="purple", label="vnode changed" ];
82 STORE->READ [ color="green" ];
83 STORE->ONLINE [ color="purple" ];
84 STORE->ERROR [ color="red", label="I/O error; scheduling salvage" ];
86 READ->READ [ color="blue", label="Vn_readers(vnp) > 0" ];
87 READ->READ [ color="purple", label="Vn_readers(vnp) > 1" ];
88 READ->ONLINE [ color="purple", label="Vn_readers(vnp) == 1" ];