Merge remote-tracking branch 'remotes/hreitz/tags/pull-block-2021-09-01' into staging

Block patches:
- Make the backup-top filter driver available for user-created block
  nodes (i.e. via blockdev-add)
- Allow running iotests with gdb or valgrind being attached to qemu
  instances
- Fix the raw format driver's permissions: There is no metadata, so we
  only need WRITE or RESIZE when the parent needs it
- Basic reopen implementation for win32 files (file-win32.c) so that
  qemu-img commit can work
- uclibc/musl build fix for the FUSE export code
- Some iotests delinting
- block-hmp-cmds.c refactoring

# gpg: Signature made Wed 01 Sep 2021 16:01:54 BST
# gpg:                using RSA key CB62D7A0EE3829E45F004D34A1FA40D098019CDF
# gpg:                issuer "hreitz@redhat.com"
# gpg: Good signature from "Hanna Reitz <hreitz@redhat.com>" [marginal]
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: CB62 D7A0 EE38 29E4 5F00  4D34 A1FA 40D0 9801 9CDF

* remotes/hreitz/tags/pull-block-2021-09-01: (56 commits)
  block/file-win32: add reopen handlers
  block/export/fuse.c: fix fuse-lseek on uclibc or musl
  block/block-copy: block_copy_state_new(): drop extra arguments
  iotests/image-fleecing: add test-case for copy-before-write filter
  iotests/image-fleecing: prepare for adding new test-case
  iotests/image-fleecing: rename tgt_node
  iotests/image-fleecing: proper source device
  iotests.py: hmp_qemu_io: support qdev
  iotests: move 222 to tests/image-fleecing
  iotests/222: constantly use single quotes for strings
  iotests/222: fix pylint and mypy complains
  python:QEMUMachine: template typing for self returning methods
  python/qemu/machine: QEMUMachine: improve qmp() method
  python/qemu/machine.py: refactor _qemu_args()
  qapi: publish copy-before-write filter
  block/copy-before-write: make public block driver
  block/block-copy: make setting progress optional
  block/copy-before-write: initialize block-copy bitmap
  block/copy-before-write: cbw_init(): use options
  block/copy-before-write: bdrv_cbw_append(): drop unused compress arg
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 31 insertions, 12 deletions

diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index 2760c21f11..e71f5d64d1 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -36,11 +36,11 @@
 
 static bool check_prop_still_unset(Object *obj, const char *name,
                                    const void *old_val, const char *new_val,
-                                   Error **errp)
+                                   bool allow_override, Error **errp)
 {
     const GlobalProperty *prop = qdev_find_global_prop(obj, name);
 
-    if (!old_val) {
+    if (!old_val || (!prop && allow_override)) {
         return true;
     }
 
@@ -93,16 +93,34 @@ static void set_drive_helper(Object *obj, Visitor *v, const char *name,
     BlockBackend *blk;
     bool blk_created = false;
     int ret;
+    BlockDriverState *bs;
+    AioContext *ctx;
 
     if (!visit_type_str(v, name, &str, errp)) {
         return;
     }
 
-    /*
-     * TODO Should this really be an error?  If no, the old value
-     * needs to be released before we store the new one.
-     */
-    if (!check_prop_still_unset(obj, name, *ptr, str, errp)) {
+    if (!check_prop_still_unset(obj, name, *ptr, str, true, errp)) {
+        return;
+    }
+
+    if (*ptr) {
+        /* BlockBackend alread exists. So, we want to change attached node */
+        blk = *ptr;
+        ctx = blk_get_aio_context(blk);
+        bs = bdrv_lookup_bs(NULL, str, errp);
+        if (!bs) {
+            return;
+        }
+
+        if (ctx != bdrv_get_aio_context(bs)) {
+            error_setg(errp, "Different aio context is not supported for new "
+                       "node");
+        }
+
+        aio_context_acquire(ctx);
+        blk_replace_bs(blk, bs, errp);
+        aio_context_release(ctx);
         return;
     }
 
@@ -114,7 +132,7 @@ static void set_drive_helper(Object *obj, Visitor *v, const char *name,
 
     blk = blk_by_name(str);
     if (!blk) {
-        BlockDriverState *bs = bdrv_lookup_bs(NULL, str, NULL);
+        bs = bdrv_lookup_bs(NULL, str, NULL);
         if (bs) {
             /*
              * If the device supports iothreads, it will make sure to move the
@@ -123,8 +141,7 @@ static void set_drive_helper(Object *obj, Visitor *v, const char *name,
              * aware of iothreads require their BlockBackends to be in the main
              * AioContext.
              */
-            AioContext *ctx = iothread ? bdrv_get_aio_context(bs) :
-                                         qemu_get_aio_context();
+            ctx = iothread ? bdrv_get_aio_context(bs) : qemu_get_aio_context();
             blk = blk_new(ctx, 0, BLK_PERM_ALL);
             blk_created = true;
 
@@ -196,6 +213,7 @@ static void release_drive(Object *obj, const char *name, void *opaque)
 const PropertyInfo qdev_prop_drive = {
     .name  = "str",
     .description = "Node name or ID of a block device to use as a backend",
+    .realized_set_allowed = true,
     .get   = get_drive,
     .set   = set_drive,
     .release = release_drive,
@@ -204,6 +222,7 @@ const PropertyInfo qdev_prop_drive = {
 const PropertyInfo qdev_prop_drive_iothread = {
     .name  = "str",
     .description = "Node name or ID of a block device to use as a backend",
+    .realized_set_allowed = true,
     .get   = get_drive,
     .set   = set_drive_iothread,
     .release = release_drive,
@@ -238,7 +257,7 @@ static void set_chr(Object *obj, Visitor *v, const char *name, void *opaque,
      * TODO Should this really be an error?  If no, the old value
      * needs to be released before we store the new one.
      */
-    if (!check_prop_still_unset(obj, name, be->chr, str, errp)) {
+    if (!check_prop_still_unset(obj, name, be->chr, str, false, errp)) {
         return;
     }
 
@@ -408,7 +427,7 @@ static void set_netdev(Object *obj, Visitor *v, const char *name,
          * TODO Should this really be an error?  If no, the old value
          * needs to be released before we store the new one.
          */
-        if (!check_prop_still_unset(obj, name, ncs[i], str, errp)) {
+        if (!check_prop_still_unset(obj, name, ncs[i], str, false, errp)) {
             goto out;
         }