qemu/block/nbd-client.h
Paolo Bonzini ff82911cd3 nbd: convert to use qio_channel_yield
In the client, read the reply headers from a coroutine, switching the
read side between the "read header" coroutine and the I/O coroutine that
reads the body of the reply.

In the server, if the server can read more requests it will create a new
"read request" coroutine as soon as a request has been read.  Otherwise,
the new coroutine is created in nbd_request_put.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-8-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:14:08 +00:00

61 lines
1.8 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 NBDClientSession {
QIOChannelSocket *sioc; /* The master data channel */
QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
uint16_t nbdflags;
off_t size;
CoMutex send_mutex;
CoQueue free_sema;
Coroutine *read_reply_co;
int in_flight;
Coroutine *recv_coroutine[MAX_NBD_REQUESTS];
NBDReply reply;
bool is_unix;
} 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 count);
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 count, 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 */