Data Structures

The io bulk client design includes data structures like

m0_io_fop An in-memory definition of io fop which binds the io fop with its network buffer.

Subroutines

Constructors and Destructors

m0_io_fop_init() - Initializes the m0_io_fop structure.
m0_io_fop_fini() - Finalizes a m0_io_fop structure.

Accessors and Invariants

m0_fop_to_rpcbulk() - Retrieves struct m0_rpc_bulk from given m0_fop.

Operational Interfaces

Command Usage

Not Applicable.

Recipes

Using bulk APIs on client side.

IO bulk client allocates memory for a m0_io_fop and invokes m0_io_fop_init() by providing fop type.
IO bulk client invokes m0_rpc_bulk_buf_databuf_add() till all pages or user buffers are added to m0_rpc_bulk structure and then invokes
Bulk client invokes m0_rpc_bulk_store() to store the network buffer memory descriptor/s to io fop wire format. The network buffer memory descriptor is retrieved after adding the network buffer to transfer machine belonging to m0_rpc_machine.
Bulk client invokes m0_rpc_post() to submit the fop to rpc layer.
The network buffers added by bulk client to m0_rpc_bulk structure are removed and deallocated by network buffer completion callbacks. Bulk client user need not remove or deallocate these network buffers by itself. The m0_io_fop structure can be populated and used like this.

m0_io_fop_init(iofop, ftype);
do {
     m0_rpc_bulk_buf_add(&iofop->if_rbulk, rbuf);
     ..
     m0_rpc_bulk_buf_databuf_add(rbuf, buf, count, index);
     ..
} while (not_empty);
..
m0_rpc_bulk_buf_store(rbuf, rpcitem, net_buf_desc);
..
m0_rpc_post(rpc_item);
m0_rpc_reply_timedwait(rpc_item);
m0_io_fop_fini(iofop);

Using bulk APIs on server side.

Motr io server program (ioservice) creates a m0_rpc_bulk structure and invokes m0_rpc_bulk_init().
Ioservice invokes m0_rpc_bulk_buf_add() to attach buffers to the m0_rpc_bulk structure.
Typically, ioservice uses a pre-allocated and pre-registered pool of network buffers which are supposed to be used while doing bulk transfer. These buffers are provided while invoking m0_rpc_bulk_buf_add() API.
Ioservice invokes m0_rpc_bulk_load() to start the zero copy of data from sender. Since server side sends the reply fop, it does not need m0_io_fop structures since it deals with request IO fops.

See also: m0_rpc_bulk
m0_rpc_bulk_init(rbulk);
do {
m0_rpc_bulk_buf_add(rbulk->rbuf, segs_nr, length, netdom, nb, &out);
..
..
} while(request_io_fop->io_buf_desc_list is not finished);
m0_clink_init(&clink, NULL);
m0_clink_add_lock(&rbulk->rb_chan, &clink);
m0_rpc_bulk_buf_load(rbulk, conn, &request_io_fop->desc_list);
..
m0_chan_wait(&clink);
..
send_reply_fop();
m0_rpc_bulk_fini(rbulk);; Bulk IO client Detailed Functional Specification