xemu/block/nbd-client.h
Vladimir Sementsov-Ogievskiy f140e30003 nbd: Minimal structured read for client
Minimal implementation: for structured error only error_report error
message.

Note that test 83 is now more verbose, because the implementation
prints more warnings about unexpected communication errors; perhaps
future patches should tone things down by using trace messages
instead of traces, but the common case of successful communication
is no noisier than before.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171027104037.8319-13-eblake@redhat.com>
2017-10-30 21:48:41 +01:00

65 lines
2.0 KiB
C

#ifndef NBD_CLIENT_H
#define NBD_CLIENT_H
#include "qemu-common.h"
#include "block/nbd.h"
#include "block/block_int.h"
#include "io/channel-socket.h"
/* #define DEBUG_NBD */
#if defined(DEBUG_NBD)
#define logout(fmt, ...) \
fprintf(stderr, "nbd\t%-24s" fmt, __func__, ##__VA_ARGS__)
#else
#define logout(fmt, ...) ((void)0)
#endif
#define MAX_NBD_REQUESTS 16
typedef struct {
Coroutine *coroutine;
uint64_t offset; /* original offset of the request */
bool receiving; /* waiting for read_reply_co? */
} NBDClientRequest;
typedef struct NBDClientSession {
QIOChannelSocket *sioc; /* The master data channel */
QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
NBDExportInfo info;
CoMutex send_mutex;
CoQueue free_sema;
Coroutine *read_reply_co;
int in_flight;
NBDClientRequest requests[MAX_NBD_REQUESTS];
NBDReply reply;
bool quit;
} NBDClientSession;
NBDClientSession *nbd_get_client_session(BlockDriverState *bs);
int nbd_client_init(BlockDriverState *bs,
QIOChannelSocket *sock,
const char *export_name,
QCryptoTLSCreds *tlscreds,
const char *hostname,
Error **errp);
void nbd_client_close(BlockDriverState *bs);
int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes);
int nbd_client_co_flush(BlockDriverState *bs);
int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *qiov, int flags);
int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
int bytes, BdrvRequestFlags flags);
int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *qiov, int flags);
void nbd_client_detach_aio_context(BlockDriverState *bs);
void nbd_client_attach_aio_context(BlockDriverState *bs,
AioContext *new_context);
#endif /* NBD_CLIENT_H */