qemu-nbd: move client handling to nbd.c

This patch sets up the fd handler in nbd.c instead of qemu-nbd.c.  It
introduces NBDClient, which wraps the arguments to nbd_trip in a single
structure, so that we can add a notifier to it.  This way, qemu-nbd can
know about disconnections.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2011-09-19 14:33:23 +02:00
parent a61c67828d
commit 1743b51586
3 changed files with 66 additions and 15 deletions

62
nbd.c
View File

@ -600,6 +600,37 @@ struct NBDExport {
QSIMPLEQ_HEAD(, NBDRequest) requests;
};
struct NBDClient {
int refcount;
void (*close)(NBDClient *client);
NBDExport *exp;
int sock;
};
static void nbd_client_get(NBDClient *client)
{
client->refcount++;
}
static void nbd_client_put(NBDClient *client)
{
if (--client->refcount == 0) {
g_free(client);
}
}
static void nbd_client_close(NBDClient *client)
{
qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL);
close(client->sock);
client->sock = -1;
if (client->close) {
client->close(client);
}
nbd_client_put(client);
}
static NBDRequest *nbd_request_get(NBDExport *exp)
{
NBDRequest *req;
@ -712,9 +743,11 @@ out:
return rc;
}
int nbd_trip(NBDExport *exp, int csock)
static int nbd_trip(NBDClient *client)
{
NBDExport *exp = client->exp;
NBDRequest *req = nbd_request_get(exp);
int csock = client->sock;
struct nbd_request request;
struct nbd_reply reply;
int rc = -1;
@ -836,7 +869,30 @@ out:
return rc;
}
int nbd_negotiate(NBDExport *exp, int csock)
static void nbd_read(void *opaque)
{
return nbd_send_negotiate(csock, exp->size, exp->nbdflags);
NBDClient *client = opaque;
nbd_client_get(client);
if (nbd_trip(client) != 0) {
nbd_client_close(client);
}
nbd_client_put(client);
}
NBDClient *nbd_client_new(NBDExport *exp, int csock,
void (*close)(NBDClient *))
{
NBDClient *client;
if (nbd_send_negotiate(csock, exp->size, exp->nbdflags) == -1) {
return NULL;
}
client = g_malloc0(sizeof(NBDClient));
client->refcount = 1;
client->exp = exp;
client->sock = csock;
client->close = close;
qemu_set_fd_handler2(csock, NULL, nbd_read, NULL, client);
return client;
}

5
nbd.h
View File

@ -76,11 +76,12 @@ int nbd_client(int fd);
int nbd_disconnect(int fd);
typedef struct NBDExport NBDExport;
typedef struct NBDClient NBDClient;
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
off_t size, uint32_t nbdflags);
void nbd_export_close(NBDExport *exp);
int nbd_negotiate(NBDExport *exp, int csock);
int nbd_trip(NBDExport *exp, int csock);
NBDClient *nbd_client_new(NBDExport *exp, int csock,
void (*close)(NBDClient *));
#endif

View File

@ -249,15 +249,10 @@ static int nbd_can_accept(void *opaque)
return nb_fds < shared;
}
static void nbd_read(void *opaque)
static void nbd_client_closed(NBDClient *client)
{
int fd = (uintptr_t) opaque;
if (nbd_trip(exp, fd) != 0) {
qemu_set_fd_handler2(fd, NULL, NULL, NULL, NULL);
close(fd);
nb_fds--;
}
qemu_notify_event();
}
static void nbd_accept(void *opaque)
@ -268,8 +263,7 @@ static void nbd_accept(void *opaque)
int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
nbd_started = true;
if (fd != -1 && nbd_negotiate(exp, fd) != -1) {
qemu_set_fd_handler2(fd, NULL, nbd_read, NULL, (void *) (intptr_t) fd);
if (fd != -1 && nbd_client_new(exp, fd, nbd_client_closed)) {
nb_fds++;
}
}