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-rw-r--r--block/export/export.c14
-rw-r--r--blockdev-nbd.c2
-rw-r--r--include/block/export.h15
-rw-r--r--include/block/nbd.h2
-rw-r--r--nbd/server.c72
5 files changed, 63 insertions, 42 deletions
diff --git a/block/export/export.c b/block/export/export.c
index 05bc5e3744..baba4e94ff 100644
--- a/block/export/export.c
+++ b/block/export/export.c
@@ -49,6 +49,20 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
return drv->create(export, errp);
}
+void blk_exp_ref(BlockExport *exp)
+{
+ assert(exp->refcount > 0);
+ exp->refcount++;
+}
+
+void blk_exp_unref(BlockExport *exp)
+{
+ assert(exp->refcount > 0);
+ if (--exp->refcount == 0) {
+ exp->drv->delete(exp);
+ }
+}
+
void qmp_block_export_add(BlockExportOptions *export, Error **errp)
{
blk_exp_add(export, errp);
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 7bb0b09697..e208324d42 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -236,7 +236,7 @@ BlockExport *nbd_export_create(BlockExportOptions *exp_args, Error **errp)
/* The list of named exports has a strong reference to this export now and
* our only way of accessing it is through nbd_export_find(), so we can drop
* the strong reference that is @exp. */
- nbd_export_put(exp);
+ blk_exp_unref((BlockExport*) exp);
out:
aio_context_release(aio_context);
diff --git a/include/block/export.h b/include/block/export.h
index e7af2c7687..5236a35e12 100644
--- a/include/block/export.h
+++ b/include/block/export.h
@@ -24,12 +24,27 @@ typedef struct BlockExportDriver {
/* Creates and starts a new block export */
BlockExport *(*create)(BlockExportOptions *, Error **);
+
+ /*
+ * Frees a removed block export. This function is only called after all
+ * references have been dropped.
+ */
+ void (*delete)(BlockExport *);
} BlockExportDriver;
struct BlockExport {
const BlockExportDriver *drv;
+
+ /*
+ * Reference count for this block export. This includes strong references
+ * both from the owner (qemu-nbd or the monitor) and clients connected to
+ * the export.
+ */
+ int refcount;
};
BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp);
+void blk_exp_ref(BlockExport *exp);
+void blk_exp_unref(BlockExport *exp);
#endif
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 1dafe70615..e3bd112227 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -338,8 +338,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs,
void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk);
void nbd_export_close(NBDExport *exp);
void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp);
-void nbd_export_get(NBDExport *exp);
-void nbd_export_put(NBDExport *exp);
AioContext *nbd_export_aio_context(NBDExport *exp);
NBDExport *nbd_export_find(const char *name);
diff --git a/nbd/server.c b/nbd/server.c
index fb70374df5..7be81c7bda 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -83,7 +83,6 @@ struct NBDRequestData {
struct NBDExport {
BlockExport common;
- int refcount;
BlockBackend *blk;
char *name;
@@ -499,7 +498,7 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, bool no_zeroes,
}
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
- nbd_export_get(client->exp);
+ blk_exp_ref(&client->exp->common);
nbd_check_meta_export(client);
return 0;
@@ -707,7 +706,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, Error **errp)
client->exp = exp;
client->check_align = check_align;
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
- nbd_export_get(client->exp);
+ blk_exp_ref(&client->exp->common);
nbd_check_meta_export(client);
rc = 1;
}
@@ -1406,7 +1405,7 @@ void nbd_client_put(NBDClient *client)
g_free(client->tlsauthz);
if (client->exp) {
QTAILQ_REMOVE(&client->exp->clients, client, next);
- nbd_export_put(client->exp);
+ blk_exp_unref(&client->exp->common);
}
g_free(client);
}
@@ -1538,7 +1537,8 @@ NBDExport *nbd_export_new(BlockDriverState *bs,
exp = g_new0(NBDExport, 1);
exp->common = (BlockExport) {
- .drv = &blk_exp_nbd,
+ .drv = &blk_exp_nbd,
+ .refcount = 1,
};
/*
@@ -1567,7 +1567,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs,
blk_set_enable_write_cache(blk, !writethrough);
blk_set_allow_aio_context_change(blk, true);
- exp->refcount = 1;
QTAILQ_INIT(&exp->clients);
exp->blk = blk;
exp->name = g_strdup(name);
@@ -1626,8 +1625,9 @@ NBDExport *nbd_export_new(BlockDriverState *bs,
exp->ctx = ctx;
blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp);
+ blk_exp_ref(&exp->common);
QTAILQ_INSERT_TAIL(&exports, exp, next);
- nbd_export_get(exp);
+
return exp;
fail:
@@ -1660,7 +1660,7 @@ void nbd_export_close(NBDExport *exp)
{
NBDClient *client, *next;
- nbd_export_get(exp);
+ blk_exp_ref(&exp->common);
/*
* TODO: Should we expand QMP NbdServerRemoveNode enum to allow a
* close mode that stops advertising the export to new clients but
@@ -1672,13 +1672,13 @@ void nbd_export_close(NBDExport *exp)
client_close(client, true);
}
if (exp->name) {
- nbd_export_put(exp);
+ blk_exp_unref(&exp->common);
g_free(exp->name);
exp->name = NULL;
QTAILQ_REMOVE(&exports, exp, next);
QTAILQ_INSERT_TAIL(&closed_exports, exp, next);
}
- nbd_export_put(exp);
+ blk_exp_unref(&exp->common);
}
void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp)
@@ -1695,47 +1695,41 @@ void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp)
error_append_hint(errp, "Use mode='hard' to force client disconnect\n");
}
-void nbd_export_get(NBDExport *exp)
-{
- assert(exp->refcount > 0);
- exp->refcount++;
-}
-
-void nbd_export_put(NBDExport *exp)
+static void nbd_export_delete(BlockExport *blk_exp)
{
- assert(exp->refcount > 0);
- if (--exp->refcount == 0) {
- assert(exp->name == NULL);
- assert(QTAILQ_EMPTY(&exp->clients));
+ NBDExport *exp = container_of(blk_exp, NBDExport, common);
- g_free(exp->description);
- exp->description = NULL;
+ assert(exp->name == NULL);
+ assert(QTAILQ_EMPTY(&exp->clients));
- if (exp->blk) {
- if (exp->eject_notifier_blk) {
- notifier_remove(&exp->eject_notifier);
- blk_unref(exp->eject_notifier_blk);
- }
- blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
- blk_aio_detach, exp);
- blk_unref(exp->blk);
- exp->blk = NULL;
- }
+ g_free(exp->description);
+ exp->description = NULL;
- if (exp->export_bitmap) {
- bdrv_dirty_bitmap_set_busy(exp->export_bitmap, false);
- g_free(exp->export_bitmap_context);
+ if (exp->blk) {
+ if (exp->eject_notifier_blk) {
+ notifier_remove(&exp->eject_notifier);
+ blk_unref(exp->eject_notifier_blk);
}
+ blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
+ blk_aio_detach, exp);
+ blk_unref(exp->blk);
+ exp->blk = NULL;
+ }
- QTAILQ_REMOVE(&closed_exports, exp, next);
- g_free(exp);
- aio_wait_kick();
+ if (exp->export_bitmap) {
+ bdrv_dirty_bitmap_set_busy(exp->export_bitmap, false);
+ g_free(exp->export_bitmap_context);
}
+
+ QTAILQ_REMOVE(&closed_exports, exp, next);
+ g_free(exp);
+ aio_wait_kick();
}
const BlockExportDriver blk_exp_nbd = {
.type = BLOCK_EXPORT_TYPE_NBD,
.create = nbd_export_create,
+ .delete = nbd_export_delete,
};
void nbd_export_close_all(void)
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-12-18 10:59:03 +0100