qcow2_create2() calls qemu_co_mutex_lock().  Only a coroutine_fn may
call another coroutine_fn.

Rename the function (the block layer API is now called
.bdrv_co_create()) and add coroutine_fn.  It is always called from
coroutine context.

Reported-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/qcow2.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 5279839..b0ae612 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2140,11 +2140,12 @@ static int preallocate(BlockDriverState *bs)
     return 0;
 }
 
-static int qcow2_create2(const char *filename, int64_t total_size,
-                         const char *backing_file, const char *backing_format,
-                         int flags, size_t cluster_size, PreallocMode prealloc,
-                         QemuOpts *opts, int version, int refcount_order,
-                         Error **errp)
+static int coroutine_fn
+qcow2_co_create2(const char *filename, int64_t total_size,
+                 const char *backing_file, const char *backing_format,
+                 int flags, size_t cluster_size, PreallocMode prealloc,
+                 QemuOpts *opts, int version, int refcount_order,
+                 Error **errp)
 {
     int cluster_bits;
     QDict *options;
@@ -2476,9 +2477,9 @@ static int coroutine_fn qcow2_co_create(const char *filename, QemuOpts *opts,
 
     refcount_order = ctz32(refcount_bits);
 
-    ret = qcow2_create2(filename, size, backing_file, backing_fmt, flags,
-                        cluster_size, prealloc, opts, version, refcount_order,
-                        &local_err);
+    ret = qcow2_co_create2(filename, size, backing_file, backing_fmt, flags,
+                           cluster_size, prealloc, opts, version,
+                           refcount_order, &local_err);
     error_propagate(errp, local_err);
 
 finish:
-- 
2.9.4

Am 05.07.2017 um 12:22 hat Stefan Hajnoczi geschrieben:
> qcow2_create2() calls qemu_co_mutex_lock().  Only a coroutine_fn may
> call another coroutine_fn.
> 
> Rename the function (the block layer API is now called
> .bdrv_co_create()) and add coroutine_fn.  It is always called from
> coroutine context.
> 
> Reported-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>