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/* NBD client library in userspace
* Copyright Red Hat
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <inttypes.h>
#include <errno.h>
#include <assert.h>
#include "internal.h"
/* Internal function which retires and frees a command. */
void
nbd_internal_retire_and_free_command (struct command *cmd)
{
/* Free the callbacks. */
if (cmd->type == NBD_CMD_BLOCK_STATUS) {
if (cmd->cb.wide)
FREE_CALLBACK (cmd->cb.fn.extent64);
else
FREE_CALLBACK (cmd->cb.fn.extent32);
if (cmd->ids) {
uint32_vector_reset (cmd->ids);
free (cmd->ids);
}
}
if (cmd->type == NBD_CMD_READ)
FREE_CALLBACK (cmd->cb.fn.chunk);
FREE_CALLBACK (cmd->cb.completion);
free (cmd);
}
int
nbd_unlocked_aio_get_fd (struct nbd_handle *h)
{
if (!h->sock) {
set_error (EINVAL, "connection is not in a connected state");
return -1;
}
return h->sock->ops->get_fd (h->sock);
}
int
nbd_unlocked_aio_notify_read (struct nbd_handle *h)
{
return nbd_internal_run (h, notify_read);
}
int
nbd_unlocked_aio_notify_write (struct nbd_handle *h)
{
return nbd_internal_run (h, notify_write);
}
int
nbd_unlocked_aio_command_completed (struct nbd_handle *h,
uint64_t cookie)
{
struct command *prev_cmd, *cmd;
uint16_t type;
uint32_t error;
if (cookie < 1) {
set_error (EINVAL, "invalid aio cookie %" PRId64, cookie);
return -1;
}
/* Find the command amongst the completed commands. */
for (cmd = h->cmds_done, prev_cmd = NULL;
cmd != NULL;
prev_cmd = cmd, cmd = cmd->next) {
if (cmd->cookie == cookie)
break;
}
if (!cmd)
return 0;
type = cmd->type;
error = cmd->error;
assert (cmd->type != NBD_CMD_DISC);
/* The spec states that a 0-length read request is unspecified; but
* it is easy enough to treat it as successful as an extension.
* Conversely, make sure a server sending structured replies sent
* enough data chunks to cover the overall count (although we do not
* detect if it duplicated some bytes while omitting others).
*/
if (type == NBD_CMD_READ && cmd->data_seen != cmd->count && !error) {
debug (h, "server sent wrong byte length without error; using EPROTO");
error = EPROTO;
}
/* Retire it from the list and free it. */
if (h->cmds_done_tail == cmd) {
assert (cmd->next == NULL);
h->cmds_done_tail = prev_cmd;
}
if (prev_cmd != NULL)
prev_cmd->next = cmd->next;
else
h->cmds_done = cmd->next;
nbd_internal_retire_and_free_command (cmd);
/* If the command was successful, return true. */
if (error == 0)
return 1;
/* The command failed, set an error indication and return an error. */
set_error (error, "%s: command failed",
nbd_internal_name_of_nbd_cmd (type));
return -1;
}
int64_t
nbd_unlocked_aio_peek_command_completed (struct nbd_handle *h)
{
if (h->cmds_done != NULL) {
assert (h->cmds_done->type != NBD_CMD_DISC);
return h->cmds_done->cookie;
}
if (h->cmds_in_flight != NULL || h->cmds_to_issue != NULL) {
set_error (0, "no in-flight command has completed yet");
return 0;
}
set_error (EINVAL, "no commands are in flight");
return -1;
}
int
nbd_unlocked_aio_in_flight (struct nbd_handle *h)
{
return h->in_flight;
}
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