Merge remote-tracking branch 'stefanha/block' into staging

# By Stefan Hajnoczi (14) and others
# Via Stefan Hajnoczi
* stefanha/block: (28 commits)
  blockdev: Fix up copyright and permission notice
  qemu-iotests: use -nographic in test case 007
  qemu-iotests: add tests for rebasing zero clusters
  dataplane: fix hang introduced by AioContext transition
  coroutine: use AioContext for CoQueue BH
  threadpool: drop global thread pool
  block: add bdrv_get_aio_context()
  aio: add a ThreadPool instance to AioContext
  threadpool: add thread_pool_new() and thread_pool_free()
  threadpool: move globals into struct ThreadPool
  main-loop: add qemu_get_aio_context()
  sheepdog: set io_flush handler in do_co_req
  sheepdog: use non-blocking fd in coroutine context
  qcow2: make is_allocated return true for zero clusters
  qcow2: drop unnecessary flush in qcow2_update_snapshot_refcount()
  qcow2: drop flush in update_cluster_refcount()
  qcow2: flush in qcow2_update_snapshot_refcount()
  qcow2: set L2 cache dependency in qcow2_alloc_bytes()
  qcow2: flush refcount cache correctly in qcow2_write_snapshots()
  qcow2: flush refcount cache correctly in alloc_refcount_block()
  ...

1 files changed, 13 insertions, 6 deletions

diff --git a/block/sheepdog.c b/block/sheepdog.c
index c711c28..4245328 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -468,6 +468,8 @@ static int connect_to_sdog(BDRVSheepdogState *s)
     if (err != NULL) {
         qerror_report_err(err);
         error_free(err);
+    } else {
+        socket_set_nonblock(fd);
     }
 
     return fd;
@@ -499,6 +501,13 @@ static void restart_co_req(void *opaque)
     qemu_coroutine_enter(co, NULL);
 }
 
+static int have_co_req(void *opaque)
+{
+    /* this handler is set only when there is a pending request, so
+     * always returns 1. */
+    return 1;
+}
+
 typedef struct SheepdogReqCo {
     int sockfd;
     SheepdogReq *hdr;
@@ -521,15 +530,14 @@ static coroutine_fn void do_co_req(void *opaque)
     unsigned int *rlen = srco->rlen;
 
     co = qemu_coroutine_self();
-    qemu_aio_set_fd_handler(sockfd, NULL, restart_co_req, NULL, co);
+    qemu_aio_set_fd_handler(sockfd, NULL, restart_co_req, have_co_req, co);
 
-    socket_set_block(sockfd);
     ret = send_co_req(sockfd, hdr, data, wlen);
     if (ret < 0) {
         goto out;
     }
 
-    qemu_aio_set_fd_handler(sockfd, restart_co_req, NULL, NULL, co);
+    qemu_aio_set_fd_handler(sockfd, restart_co_req, NULL, have_co_req, co);
 
     ret = qemu_co_recv(sockfd, hdr, sizeof(*hdr));
     if (ret < sizeof(*hdr)) {
@@ -552,8 +560,9 @@ static coroutine_fn void do_co_req(void *opaque)
     }
     ret = 0;
 out:
+    /* there is at most one request for this sockfd, so it is safe to
+     * set each handler to NULL. */
     qemu_aio_set_fd_handler(sockfd, NULL, NULL, NULL, NULL);
-    socket_set_nonblock(sockfd);
 
     srco->ret = ret;
     srco->finished = true;
@@ -776,8 +785,6 @@ static int get_sheep_fd(BDRVSheepdogState *s)
         return fd;
     }
 
-    socket_set_nonblock(fd);
-
     qemu_aio_set_fd_handler(fd, co_read_response, NULL, aio_flush_request, s);
     return fd;
 }