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authorPaolo Bonzini <pbonzini@redhat.com>2012-09-18 13:26:25 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2012-09-19 15:26:28 +0200
commit2c8d9f065538a5a0ef2421e90b6076d05148accf (patch)
treee302eabc6302f61e5a2f1c41f7afe7b06f7cbdab /nbd.c
parentff2b68aa70d10b7eae813b04e9a23723dbd89ebd (diff)
downloadqemu-arm-2c8d9f065538a5a0ef2421e90b6076d05148accf.tar.gz
nbd: add reference counting to NBDExport
We will use a similar two-phase destruction for NBDExport, so we need each NBDClient to add a reference to NBDExport. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'nbd.c')
-rw-r--r--nbd.c37
1 files changed, 31 insertions, 6 deletions
diff --git a/nbd.c b/nbd.c
index eb72f4a6e5..4922d38ea3 100644
--- a/nbd.c
+++ b/nbd.c
@@ -89,6 +89,7 @@ struct NBDRequest {
};
struct NBDExport {
+ int refcount;
BlockDriverState *bs;
off_t dev_offset;
off_t size;
@@ -664,6 +665,7 @@ void nbd_client_put(NBDClient *client)
qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL);
close(client->sock);
client->sock = -1;
+ nbd_export_put(client->exp);
g_free(client);
}
}
@@ -722,6 +724,7 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
{
NBDExport *exp = g_malloc0(sizeof(NBDExport));
QSIMPLEQ_INIT(&exp->requests);
+ exp->refcount = 1;
exp->bs = bs;
exp->dev_offset = dev_offset;
exp->nbdflags = nbdflags;
@@ -731,14 +734,34 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
void nbd_export_close(NBDExport *exp)
{
- while (!QSIMPLEQ_EMPTY(&exp->requests)) {
- NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests);
- QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);
- qemu_vfree(first->data);
- g_free(first);
+ assert(exp->refcount == 1);
+
+ /* stub */
+}
+
+void nbd_export_get(NBDExport *exp)
+{
+ assert(exp->refcount > 0);
+ exp->refcount++;
+}
+
+void nbd_export_put(NBDExport *exp)
+{
+ assert(exp->refcount > 0);
+ if (exp->refcount == 1) {
+ nbd_export_close(exp);
}
- g_free(exp);
+ if (--exp->refcount == 0) {
+ while (!QSIMPLEQ_EMPTY(&exp->requests)) {
+ NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests);
+ QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);
+ qemu_vfree(first->data);
+ g_free(first);
+ }
+
+ g_free(exp);
+ }
}
static int nbd_can_read(void *opaque);
@@ -1011,5 +1034,7 @@ NBDClient *nbd_client_new(NBDExport *exp, int csock,
client->close = close;
qemu_co_mutex_init(&client->send_lock);
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
+
+ nbd_export_get(exp);
return client;
}