5 OST_STATFS is an RPC that queries data about the underlying file
6 system for a given OST.
8 The OST_STATFS request message is a so-called "empty" message in that
9 it only has a buffer for the 'ptlrpc_body' with the 'pb_opc' value
12 The reply message conveys 'statfs' data when it succeeds, and an error
15 .OST_STATFS Generic Packet Structure
16 image::ost-statfs-generic.png["OST_STATFS Generic Packet Structure",height=100]
18 //////////////////////////////////////////////////////////////////////
19 The ost-statfs-generic.png diagram resembles this text art:
25 --reply---------------------
26 | ptlrpc_body | obd_statfs |
27 ----------------------------
28 //////////////////////////////////////////////////////////////////////
30 'ptlrpc_body':: RPC descriptor. Only the 'pb_opc' value (OST_STATFS =
31 41) is directly relevant to the OST_STATFS request message. The rest
32 of the 'ptlrpc_body' fields handle generic information about the
33 RPC, as discussed in <<struct-ptlrpc-body>>, including generic error
34 conditions. In a normal reply ('pb_type' = PTL_RPC_MSG_REPLY) the
35 'pb_status' field is 0. The one error that can be returned in
36 'pb_status' that is speficially from OST_STATFS' handling is -ENOMEM,
37 which occurs if there is not enough memory to allocate a temporary
38 buffer for the 'statfs' data.
40 include::struct_obd_statfs.txt[]