* Both sets of permissions can be changed later using blk_set_perm().
*
* Return the new BlockBackend on success, null on failure.
+ *
+ * Callers must hold the AioContext lock of @bs.
*/
BlockBackend *blk_new_with_bs(BlockDriverState *bs, uint64_t perm,
uint64_t shared_perm, Error **errp)
/*
* Creates a new BlockBackend, opens a new BlockDriverState, and connects both.
- * The new BlockBackend is in the main AioContext.
+ * By default, the new BlockBackend is in the main AioContext, but if the
+ * parameters connect it with any existing node in a different AioContext, it
+ * may end up there instead.
*
* Just as with bdrv_open(), after having called this function the reference to
* @options belongs to the block layer (even on failure).
*
+ * Called without holding an AioContext lock.
+ *
* TODO: Remove @filename and @flags; it should be possible to specify a whole
* BDS tree just by specifying the @options QDict (or @reference,
* alternatively). At the time of adding this function, this is not possible,
{
BlockBackend *blk;
BlockDriverState *bs;
+ AioContext *ctx;
uint64_t perm = 0;
uint64_t shared = BLK_PERM_ALL;
shared = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED;
}
- blk = blk_new(qemu_get_aio_context(), perm, shared);
+ aio_context_acquire(qemu_get_aio_context());
bs = bdrv_open(filename, reference, options, flags, errp);
+ aio_context_release(qemu_get_aio_context());
if (!bs) {
- blk_unref(blk);
return NULL;
}
- blk->root = bdrv_root_attach_child(bs, "root", &child_root,
- BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
- perm, shared, blk, errp);
+ /* bdrv_open() could have moved bs to a different AioContext */
+ ctx = bdrv_get_aio_context(bs);
+ blk = blk_new(bdrv_get_aio_context(bs), perm, shared);
+ blk->perm = perm;
+ blk->shared_perm = shared;
+
+ aio_context_acquire(ctx);
+ blk_insert_bs(blk, bs, errp);
+ bdrv_unref(bs);
+ aio_context_release(ctx);
+
if (!blk->root) {
blk_unref(blk);
return NULL;
/*
* Associates a new BlockDriverState with @blk.
+ *
+ * Callers must hold the AioContext lock of @bs.
*/
int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp)
{
return 0;
}
+/* Are we currently in a drained section? */
+bool blk_in_drain(BlockBackend *blk)
+{
+ GLOBAL_STATE_CODE(); /* change to IO_OR_GS_CODE(), if necessary */
+ return qatomic_read(&blk->quiesce_counter);
+}
+
/* To be called between exactly one pair of blk_inc/dec_in_flight() */
static void coroutine_fn blk_wait_while_drained(BlockBackend *blk)
{
AioContext *blk_get_aio_context(BlockBackend *blk)
{
- BlockDriverState *bs = blk_bs(blk);
+ BlockDriverState *bs;
IO_CODE();
+ if (!blk) {
+ return qemu_get_aio_context();
+ }
+
+ bs = blk_bs(blk);
if (bs) {
AioContext *ctx = bdrv_get_aio_context(blk_bs(blk));
assert(ctx == blk->ctx);
return blk_get_aio_context(blk_acb->blk);
}
-static int blk_do_set_aio_context(BlockBackend *blk, AioContext *new_context,
- bool update_root_node, Error **errp)
+int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
+ Error **errp)
{
+ bool old_allow_change;
BlockDriverState *bs = blk_bs(blk);
- ThrottleGroupMember *tgm = &blk->public.throttle_group_member;
int ret;
- if (bs) {
- bdrv_ref(bs);
-
- if (update_root_node) {
- /*
- * update_root_node MUST be false for blk_root_set_aio_ctx_commit(),
- * as we are already in the commit function of a transaction.
- */
- ret = bdrv_try_change_aio_context(bs, new_context, blk->root, errp);
- if (ret < 0) {
- bdrv_unref(bs);
- return ret;
- }
- }
- /*
- * Make blk->ctx consistent with the root node before we invoke any
- * other operations like drain that might inquire blk->ctx
- */
- blk->ctx = new_context;
- if (tgm->throttle_state) {
- bdrv_drained_begin(bs);
- throttle_group_detach_aio_context(tgm);
- throttle_group_attach_aio_context(tgm, new_context);
- bdrv_drained_end(bs);
- }
+ GLOBAL_STATE_CODE();
- bdrv_unref(bs);
- } else {
+ if (!bs) {
blk->ctx = new_context;
+ return 0;
}
- return 0;
-}
+ bdrv_ref(bs);
-int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
- Error **errp)
-{
- GLOBAL_STATE_CODE();
- return blk_do_set_aio_context(blk, new_context, true, errp);
+ old_allow_change = blk->allow_aio_context_change;
+ blk->allow_aio_context_change = true;
+
+ ret = bdrv_try_change_aio_context(bs, new_context, NULL, errp);
+
+ blk->allow_aio_context_change = old_allow_change;
+
+ bdrv_unref(bs);
+ return ret;
}
typedef struct BdrvStateBlkRootContext {
{
BdrvStateBlkRootContext *s = opaque;
BlockBackend *blk = s->blk;
+ AioContext *new_context = s->new_ctx;
+ ThrottleGroupMember *tgm = &blk->public.throttle_group_member;
- blk_do_set_aio_context(blk, s->new_ctx, false, &error_abort);
+ blk->ctx = new_context;
+ if (tgm->throttle_state) {
+ throttle_group_detach_aio_context(tgm);
+ throttle_group_attach_aio_context(tgm, new_context);
+ }
}
static TransactionActionDrv set_blk_root_context = {
notifier_list_add(&blk->insert_bs_notifiers, notify);
}
-void coroutine_fn blk_co_io_plug(BlockBackend *blk)
-{
- BlockDriverState *bs = blk_bs(blk);
- IO_CODE();
- GRAPH_RDLOCK_GUARD();
-
- if (bs) {
- bdrv_co_io_plug(bs);
- }
-}
-
-void coroutine_fn blk_co_io_unplug(BlockBackend *blk)
-{
- BlockDriverState *bs = blk_bs(blk);
- IO_CODE();
- GRAPH_RDLOCK_GUARD();
-
- if (bs) {
- bdrv_co_io_unplug(bs);
- }
-}
-
BlockAcctStats *blk_get_stats(BlockBackend *blk)
{
IO_CODE();
projects / mirror_qemu.git / blobdiff