diff mbox series

[PULL,v3,04/35] block: Call .drain_begin only once in bdrv_drain_all_begin()

Message ID 20171222151846.28110-5-kwolf@redhat.com
State New
Headers show
Series [PULL,v3,01/35] block: Formats don't need CONSISTENT_READ with NO_IO | expand

Commit Message

Kevin Wolf Dec. 22, 2017, 3:18 p.m. UTC 
bdrv_drain_all_begin() used to call the .bdrv_co_drain_begin() driver
callback inside its polling loop. This means that how many times it got
called for each node depended on long it had to poll the event loop.

This is obviously not right and results in nodes that stay drained even
after bdrv_drain_all_end(), which calls .bdrv_co_drain_begin() once per
node.

Fix bdrv_drain_all_begin() to call the callback only once, too.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/block/io.c b/block/io.c
index 096468b761..603f5b059e 100644
--- a/block/io.c
+++ b/block/io.c
@@ -355,6 +355,7 @@  void bdrv_drain_all_begin(void)
         aio_context_acquire(aio_context);
         bdrv_parent_drained_begin(bs);
         aio_disable_external(aio_context);
+        bdrv_drain_invoke(bs, true);
         aio_context_release(aio_context);
 
         if (!g_slist_find(aio_ctxs, aio_context)) {
@@ -377,8 +378,6 @@  void bdrv_drain_all_begin(void)
             aio_context_acquire(aio_context);
             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
                 if (aio_context == bdrv_get_aio_context(bs)) {
-                    /* FIXME Calling this multiple times is wrong */
-                    bdrv_drain_invoke(bs, true);
                     waited |= bdrv_drain_recurse(bs, true);
                 }
             }