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authorKevin Wolf <kwolf@redhat.com>2018-03-22 14:11:20 +0100
committerKevin Wolf <kwolf@redhat.com>2018-06-18 15:03:25 +0200
commit89bd030533e3592ca0a995450dcfc5d53e459e20 (patch)
tree565f35b4251f99f5ea34d1d19f03a979f36c6df8 /block/io.c
parent1cc8e54ada97f7ac479554e15ca9e426c895b158 (diff)
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block: Really pause block jobs on drain
We already requested that block jobs be paused in .bdrv_drained_begin, but no guarantee was made that the job was actually inactive at the point where bdrv_drained_begin() returned. This introduces a new callback BdrvChildRole.bdrv_drained_poll() and uses it to make bdrv_drain_poll() consider block jobs using the node to be drained. For the test case to work as expected, we have to switch from block_job_sleep_ns() to qemu_co_sleep_ns() so that the test job is even considered active and must be waited for when draining the node. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/io.c')
-rw-r--r--block/io.c40
1 files changed, 34 insertions, 6 deletions
diff --git a/block/io.c b/block/io.c
index bc7a2d7..5820e73 100644
--- a/block/io.c
+++ b/block/io.c
@@ -69,6 +69,23 @@ void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore)
}
}
+static bool bdrv_parent_drained_poll(BlockDriverState *bs, BdrvChild *ignore)
+{
+ BdrvChild *c, *next;
+ bool busy = false;
+
+ QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) {
+ if (c == ignore) {
+ continue;
+ }
+ if (c->role->drained_poll) {
+ busy |= c->role->drained_poll(c);
+ }
+ }
+
+ return busy;
+}
+
static void bdrv_merge_limits(BlockLimits *dst, const BlockLimits *src)
{
dst->opt_transfer = MAX(dst->opt_transfer, src->opt_transfer);
@@ -183,21 +200,32 @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)
}
/* Returns true if BDRV_POLL_WHILE() should go into a blocking aio_poll() */
-static bool bdrv_drain_poll(BlockDriverState *bs)
+bool bdrv_drain_poll(BlockDriverState *bs, BdrvChild *ignore_parent)
+{
+ if (bdrv_parent_drained_poll(bs, ignore_parent)) {
+ return true;
+ }
+
+ return atomic_read(&bs->in_flight);
+}
+
+static bool bdrv_drain_poll_top_level(BlockDriverState *bs,
+ BdrvChild *ignore_parent)
{
/* Execute pending BHs first and check everything else only after the BHs
* have executed. */
while (aio_poll(bs->aio_context, false));
- return atomic_read(&bs->in_flight);
+
+ return bdrv_drain_poll(bs, ignore_parent);
}
-static bool bdrv_drain_recurse(BlockDriverState *bs)
+static bool bdrv_drain_recurse(BlockDriverState *bs, BdrvChild *parent)
{
BdrvChild *child, *tmp;
bool waited;
/* Wait for drained requests to finish */
- waited = BDRV_POLL_WHILE(bs, bdrv_drain_poll(bs));
+ waited = BDRV_POLL_WHILE(bs, bdrv_drain_poll_top_level(bs, parent));
QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {
BlockDriverState *bs = child->bs;
@@ -214,7 +242,7 @@ static bool bdrv_drain_recurse(BlockDriverState *bs)
*/
bdrv_ref(bs);
}
- waited |= bdrv_drain_recurse(bs);
+ waited |= bdrv_drain_recurse(bs, child);
if (in_main_loop) {
bdrv_unref(bs);
}
@@ -290,7 +318,7 @@ void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive,
bdrv_parent_drained_begin(bs, parent);
bdrv_drain_invoke(bs, true);
- bdrv_drain_recurse(bs);
+ bdrv_drain_recurse(bs, parent);
if (recursive) {
bs->recursive_quiesce_counter++;