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Diffstat (limited to 'block.c')
-rw-r--r--block.c61
1 files changed, 44 insertions, 17 deletions
diff --git a/block.c b/block.c
index f6e7cf4fb9..f06de58a3b 100644
--- a/block.c
+++ b/block.c
@@ -2375,21 +2375,21 @@ typedef struct BdrvReplaceChildState {
BlockDriverState *old_bs;
} BdrvReplaceChildState;
-static void bdrv_replace_child_commit(void *opaque)
+static void GRAPH_WRLOCK bdrv_replace_child_commit(void *opaque)
{
BdrvReplaceChildState *s = opaque;
GLOBAL_STATE_CODE();
- bdrv_unref(s->old_bs);
+ bdrv_schedule_unref(s->old_bs);
}
-static void bdrv_replace_child_abort(void *opaque)
+static void GRAPH_WRLOCK bdrv_replace_child_abort(void *opaque)
{
BdrvReplaceChildState *s = opaque;
BlockDriverState *new_bs = s->child->bs;
GLOBAL_STATE_CODE();
- bdrv_graph_wrlock(s->old_bs);
+ assert_bdrv_graph_writable();
/* old_bs reference is transparently moved from @s to @s->child */
if (!s->child->bs) {
@@ -2408,7 +2408,6 @@ static void bdrv_replace_child_abort(void *opaque)
assert(s->child->quiesced_parent);
bdrv_replace_child_noperm(s->child, s->old_bs);
- bdrv_graph_wrunlock();
bdrv_unref(new_bs);
}
@@ -2426,6 +2425,9 @@ static TransactionActionDrv bdrv_replace_child_drv = {
* Both @child->bs and @new_bs (if non-NULL) must be drained. @new_bs must be
* kept drained until the transaction is completed.
*
+ * After calling this function, the transaction @tran may only be completed
+ * while holding a writer lock for the graph.
+ *
* The function doesn't update permissions, caller is responsible for this.
*/
static void GRAPH_WRLOCK
@@ -2951,16 +2953,15 @@ typedef struct BdrvAttachChildCommonState {
AioContext *old_child_ctx;
} BdrvAttachChildCommonState;
-static void bdrv_attach_child_common_abort(void *opaque)
+static void GRAPH_WRLOCK bdrv_attach_child_common_abort(void *opaque)
{
BdrvAttachChildCommonState *s = opaque;
BlockDriverState *bs = s->child->bs;
GLOBAL_STATE_CODE();
+ assert_bdrv_graph_writable();
- bdrv_graph_wrlock(NULL);
bdrv_replace_child_noperm(s->child, NULL);
- bdrv_graph_wrunlock();
if (bdrv_get_aio_context(bs) != s->old_child_ctx) {
bdrv_try_change_aio_context(bs, s->old_child_ctx, NULL, &error_abort);
@@ -2984,7 +2985,7 @@ static void bdrv_attach_child_common_abort(void *opaque)
tran_commit(tran);
}
- bdrv_unref(bs);
+ bdrv_schedule_unref(bs);
bdrv_child_free(s->child);
}
@@ -2998,6 +2999,9 @@ static TransactionActionDrv bdrv_attach_child_common_drv = {
*
* Function doesn't update permissions, caller is responsible for this.
*
+ * After calling this function, the transaction @tran may only be completed
+ * while holding a writer lock for the graph.
+ *
* Returns new created child.
*
* The caller must hold the AioContext lock for @child_bs. Both @parent_bs and
@@ -3114,6 +3118,9 @@ bdrv_attach_child_common(BlockDriverState *child_bs,
* The caller must hold the AioContext lock for @child_bs. Both @parent_bs and
* @child_bs can move to a different AioContext in this function. Callers must
* make sure that their AioContext locking is still correct after this.
+ *
+ * After calling this function, the transaction @tran may only be completed
+ * while holding a writer lock for the graph.
*/
static BdrvChild * GRAPH_WRLOCK
bdrv_attach_child_noperm(BlockDriverState *parent_bs,
@@ -3180,8 +3187,8 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
ret = bdrv_refresh_perms(child_bs, tran, errp);
out:
- bdrv_graph_wrunlock();
tran_finalize(tran, ret);
+ bdrv_graph_wrunlock();
bdrv_unref(child_bs);
@@ -3227,8 +3234,8 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
}
out:
- bdrv_graph_wrunlock();
tran_finalize(tran, ret);
+ bdrv_graph_wrunlock();
bdrv_unref(child_bs);
@@ -3393,6 +3400,9 @@ static BdrvChildRole bdrv_backing_role(BlockDriverState *bs)
* The caller must hold the AioContext lock for @child_bs. Both @parent_bs and
* @child_bs can move to a different AioContext in this function. Callers must
* make sure that their AioContext locking is still correct after this.
+ *
+ * After calling this function, the transaction @tran may only be completed
+ * while holding a writer lock for the graph.
*/
static int GRAPH_WRLOCK
bdrv_set_file_or_backing_noperm(BlockDriverState *parent_bs,
@@ -3488,6 +3498,9 @@ out:
*
* If a backing child is already present (i.e. we're detaching a node), that
* child node must be drained.
+ *
+ * After calling this function, the transaction @tran may only be completed
+ * while holding a writer lock for the graph.
*/
static int GRAPH_WRLOCK
bdrv_set_backing_noperm(BlockDriverState *bs,
@@ -3519,8 +3532,8 @@ int bdrv_set_backing_hd_drained(BlockDriverState *bs,
ret = bdrv_refresh_perms(bs, tran, errp);
out:
- bdrv_graph_wrunlock();
tran_finalize(tran, ret);
+ bdrv_graph_wrunlock();
return ret;
}
@@ -4594,7 +4607,9 @@ int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp)
aio_context_release(ctx);
}
+ bdrv_graph_wrlock(NULL);
tran_commit(tran);
+ bdrv_graph_wrunlock();
QTAILQ_FOREACH_REVERSE(bs_entry, bs_queue, entry) {
BlockDriverState *bs = bs_entry->state.bs;
@@ -4611,7 +4626,9 @@ int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp)
goto cleanup;
abort:
+ bdrv_graph_wrlock(NULL);
tran_abort(tran);
+ bdrv_graph_wrunlock();
QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
if (bs_entry->prepared) {
@@ -4678,6 +4695,9 @@ int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
* true and reopen_state->new_backing_bs contains a pointer to the new
* backing BlockDriverState (or NULL).
*
+ * After calling this function, the transaction @tran may only be completed
+ * while holding a writer lock for the graph.
+ *
* Return 0 on success, otherwise return < 0 and set @errp.
*
* The caller must hold the AioContext lock of @reopen_state->bs.
@@ -4811,6 +4831,9 @@ static int bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state,
* commit() for any other BDS that have been left in a prepare() state
*
* The caller must hold the AioContext lock of @reopen_state->bs.
+ *
+ * After calling this function, the transaction @change_child_tran may only be
+ * completed while holding a writer lock for the graph.
*/
static int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue,
@@ -5262,6 +5285,9 @@ static TransactionActionDrv bdrv_remove_child_drv = {
* Function doesn't update permissions, caller is responsible for this.
*
* @child->bs (if non-NULL) must be drained.
+ *
+ * After calling this function, the transaction @tran may only be completed
+ * while holding a writer lock for the graph.
*/
static void GRAPH_WRLOCK bdrv_remove_child(BdrvChild *child, Transaction *tran)
{
@@ -5280,6 +5306,9 @@ static void GRAPH_WRLOCK bdrv_remove_child(BdrvChild *child, Transaction *tran)
/*
* Both @from and @to (if non-NULL) must be drained. @to must be kept drained
* until the transaction is completed.
+ *
+ * After calling this function, the transaction @tran may only be completed
+ * while holding a writer lock for the graph.
*/
static int GRAPH_WRLOCK
bdrv_replace_node_noperm(BlockDriverState *from,
@@ -5386,8 +5415,8 @@ static int bdrv_replace_node_common(BlockDriverState *from,
ret = 0;
out:
- bdrv_graph_wrunlock();
tran_finalize(tran, ret);
+ bdrv_graph_wrunlock();
bdrv_drained_end(to);
bdrv_drained_end(from);
@@ -5483,12 +5512,10 @@ int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
ret = bdrv_refresh_perms(bs_new, tran, errp);
out:
- bdrv_graph_wrunlock();
tran_finalize(tran, ret);
- bdrv_graph_rdlock_main_loop();
bdrv_refresh_limits(bs_top, NULL, NULL);
- bdrv_graph_rdunlock_main_loop();
+ bdrv_graph_wrunlock();
bdrv_drained_end(bs_top);
bdrv_drained_end(bs_new);
@@ -5523,10 +5550,10 @@ int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
refresh_list = g_slist_prepend(refresh_list, new_bs);
ret = bdrv_list_refresh_perms(refresh_list, NULL, tran, errp);
- bdrv_graph_wrunlock();
tran_finalize(tran, ret);
+ bdrv_graph_wrunlock();
bdrv_drained_end(old_bs);
bdrv_drained_end(new_bs);
bdrv_unref(old_bs);