block: Introduce bdrv_co_change_backing_file()
bdrv_change_backing_file() is called both inside and outside coroutine
context. This makes it difficult for it to take the graph lock
internally. It also means that driver implementations need to be able to
run outside of coroutines, too. Switch it to the usual model with a
coroutine based implementation and a co_wrapper instead. The new
function is marked GRAPH_RDLOCK.
As the co_wrapper now runs the function in the AioContext of the node
(as it should always have done), this is not GLOBAL_STATE_CODE() any
more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-20-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index ed0afdf..4910b95 100644
--- a/block.c
+++ b/block.c
@@ -5764,13 +5764,14 @@
* image file header
* -ENOTSUP - format driver doesn't support changing the backing file
*/
-int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
- const char *backing_fmt, bool require)
+int coroutine_fn
+bdrv_co_change_backing_file(BlockDriverState *bs, const char *backing_file,
+ const char *backing_fmt, bool require)
{
BlockDriver *drv = bs->drv;
int ret;
- GLOBAL_STATE_CODE();
+ IO_CODE();
if (!drv) {
return -ENOMEDIUM;
@@ -5785,8 +5786,8 @@
return -EINVAL;
}
- if (drv->bdrv_change_backing_file != NULL) {
- ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
+ if (drv->bdrv_co_change_backing_file != NULL) {
+ ret = drv->bdrv_co_change_backing_file(bs, backing_file, backing_fmt);
} else {
ret = -ENOTSUP;
}
diff --git a/block/qcow2.c b/block/qcow2.c
index a1443a3..875e613 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3155,8 +3155,9 @@
return ret;
}
-static int qcow2_change_backing_file(BlockDriverState *bs,
- const char *backing_file, const char *backing_fmt)
+static int coroutine_fn GRAPH_RDLOCK
+qcow2_co_change_backing_file(BlockDriverState *bs, const char *backing_file,
+ const char *backing_fmt)
{
BDRVQcow2State *s = bs->opaque;
@@ -3816,8 +3817,11 @@
backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt);
}
- ret = bdrv_change_backing_file(blk_bs(blk), qcow2_opts->backing_file,
- backing_format, false);
+ bdrv_graph_co_rdlock();
+ ret = bdrv_co_change_backing_file(blk_bs(blk), qcow2_opts->backing_file,
+ backing_format, false);
+ bdrv_graph_co_rdunlock();
+
if (ret < 0) {
error_setg_errno(errp, -ret, "Could not assign backing file '%s' "
"with format '%s'", qcow2_opts->backing_file,
@@ -6115,64 +6119,64 @@
};
BlockDriver bdrv_qcow2 = {
- .format_name = "qcow2",
- .instance_size = sizeof(BDRVQcow2State),
- .bdrv_probe = qcow2_probe,
- .bdrv_open = qcow2_open,
- .bdrv_close = qcow2_close,
- .bdrv_reopen_prepare = qcow2_reopen_prepare,
- .bdrv_reopen_commit = qcow2_reopen_commit,
- .bdrv_reopen_commit_post = qcow2_reopen_commit_post,
- .bdrv_reopen_abort = qcow2_reopen_abort,
- .bdrv_join_options = qcow2_join_options,
- .bdrv_child_perm = bdrv_default_perms,
- .bdrv_co_create_opts = qcow2_co_create_opts,
- .bdrv_co_create = qcow2_co_create,
- .bdrv_has_zero_init = qcow2_has_zero_init,
- .bdrv_co_block_status = qcow2_co_block_status,
+ .format_name = "qcow2",
+ .instance_size = sizeof(BDRVQcow2State),
+ .bdrv_probe = qcow2_probe,
+ .bdrv_open = qcow2_open,
+ .bdrv_close = qcow2_close,
+ .bdrv_reopen_prepare = qcow2_reopen_prepare,
+ .bdrv_reopen_commit = qcow2_reopen_commit,
+ .bdrv_reopen_commit_post = qcow2_reopen_commit_post,
+ .bdrv_reopen_abort = qcow2_reopen_abort,
+ .bdrv_join_options = qcow2_join_options,
+ .bdrv_child_perm = bdrv_default_perms,
+ .bdrv_co_create_opts = qcow2_co_create_opts,
+ .bdrv_co_create = qcow2_co_create,
+ .bdrv_has_zero_init = qcow2_has_zero_init,
+ .bdrv_co_block_status = qcow2_co_block_status,
- .bdrv_co_preadv_part = qcow2_co_preadv_part,
- .bdrv_co_pwritev_part = qcow2_co_pwritev_part,
- .bdrv_co_flush_to_os = qcow2_co_flush_to_os,
+ .bdrv_co_preadv_part = qcow2_co_preadv_part,
+ .bdrv_co_pwritev_part = qcow2_co_pwritev_part,
+ .bdrv_co_flush_to_os = qcow2_co_flush_to_os,
- .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
- .bdrv_co_pdiscard = qcow2_co_pdiscard,
- .bdrv_co_copy_range_from = qcow2_co_copy_range_from,
- .bdrv_co_copy_range_to = qcow2_co_copy_range_to,
- .bdrv_co_truncate = qcow2_co_truncate,
- .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part,
- .bdrv_make_empty = qcow2_make_empty,
+ .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
+ .bdrv_co_pdiscard = qcow2_co_pdiscard,
+ .bdrv_co_copy_range_from = qcow2_co_copy_range_from,
+ .bdrv_co_copy_range_to = qcow2_co_copy_range_to,
+ .bdrv_co_truncate = qcow2_co_truncate,
+ .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part,
+ .bdrv_make_empty = qcow2_make_empty,
- .bdrv_snapshot_create = qcow2_snapshot_create,
- .bdrv_snapshot_goto = qcow2_snapshot_goto,
- .bdrv_snapshot_delete = qcow2_snapshot_delete,
- .bdrv_snapshot_list = qcow2_snapshot_list,
- .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
- .bdrv_measure = qcow2_measure,
- .bdrv_co_get_info = qcow2_co_get_info,
- .bdrv_get_specific_info = qcow2_get_specific_info,
+ .bdrv_snapshot_create = qcow2_snapshot_create,
+ .bdrv_snapshot_goto = qcow2_snapshot_goto,
+ .bdrv_snapshot_delete = qcow2_snapshot_delete,
+ .bdrv_snapshot_list = qcow2_snapshot_list,
+ .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
+ .bdrv_measure = qcow2_measure,
+ .bdrv_co_get_info = qcow2_co_get_info,
+ .bdrv_get_specific_info = qcow2_get_specific_info,
- .bdrv_co_save_vmstate = qcow2_co_save_vmstate,
- .bdrv_co_load_vmstate = qcow2_co_load_vmstate,
+ .bdrv_co_save_vmstate = qcow2_co_save_vmstate,
+ .bdrv_co_load_vmstate = qcow2_co_load_vmstate,
- .is_format = true,
- .supports_backing = true,
- .bdrv_change_backing_file = qcow2_change_backing_file,
+ .is_format = true,
+ .supports_backing = true,
+ .bdrv_co_change_backing_file = qcow2_co_change_backing_file,
- .bdrv_refresh_limits = qcow2_refresh_limits,
- .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache,
- .bdrv_inactivate = qcow2_inactivate,
+ .bdrv_refresh_limits = qcow2_refresh_limits,
+ .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache,
+ .bdrv_inactivate = qcow2_inactivate,
- .create_opts = &qcow2_create_opts,
- .amend_opts = &qcow2_amend_opts,
- .strong_runtime_opts = qcow2_strong_runtime_opts,
- .mutable_opts = mutable_opts,
- .bdrv_co_check = qcow2_co_check,
- .bdrv_amend_options = qcow2_amend_options,
- .bdrv_co_amend = qcow2_co_amend,
+ .create_opts = &qcow2_create_opts,
+ .amend_opts = &qcow2_amend_opts,
+ .strong_runtime_opts = qcow2_strong_runtime_opts,
+ .mutable_opts = mutable_opts,
+ .bdrv_co_check = qcow2_co_check,
+ .bdrv_amend_options = qcow2_amend_options,
+ .bdrv_co_amend = qcow2_co_amend,
- .bdrv_detach_aio_context = qcow2_detach_aio_context,
- .bdrv_attach_aio_context = qcow2_attach_aio_context,
+ .bdrv_detach_aio_context = qcow2_detach_aio_context,
+ .bdrv_attach_aio_context = qcow2_attach_aio_context,
.bdrv_supports_persistent_dirty_bitmap =
qcow2_supports_persistent_dirty_bitmap,
diff --git a/block/qed.c b/block/qed.c
index 686ad71..996aa38 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1498,9 +1498,9 @@
return 0;
}
-static int bdrv_qed_change_backing_file(BlockDriverState *bs,
- const char *backing_file,
- const char *backing_fmt)
+static int coroutine_fn GRAPH_RDLOCK
+bdrv_qed_co_change_backing_file(BlockDriverState *bs, const char *backing_file,
+ const char *backing_fmt)
{
BDRVQEDState *s = bs->opaque;
QEDHeader new_header, le_header;
@@ -1562,7 +1562,7 @@
}
/* Write new header */
- ret = bdrv_pwrite_sync(bs->file, 0, buffer_len, buffer, 0);
+ ret = bdrv_co_pwrite_sync(bs->file, 0, buffer_len, buffer, 0);
g_free(buffer);
if (ret == 0) {
memcpy(&s->header, &new_header, sizeof(new_header));
@@ -1636,34 +1636,34 @@
};
static BlockDriver bdrv_qed = {
- .format_name = "qed",
- .instance_size = sizeof(BDRVQEDState),
- .create_opts = &qed_create_opts,
- .is_format = true,
- .supports_backing = true,
+ .format_name = "qed",
+ .instance_size = sizeof(BDRVQEDState),
+ .create_opts = &qed_create_opts,
+ .is_format = true,
+ .supports_backing = true,
- .bdrv_probe = bdrv_qed_probe,
- .bdrv_open = bdrv_qed_open,
- .bdrv_close = bdrv_qed_close,
- .bdrv_reopen_prepare = bdrv_qed_reopen_prepare,
- .bdrv_child_perm = bdrv_default_perms,
- .bdrv_co_create = bdrv_qed_co_create,
- .bdrv_co_create_opts = bdrv_qed_co_create_opts,
- .bdrv_has_zero_init = bdrv_has_zero_init_1,
- .bdrv_co_block_status = bdrv_qed_co_block_status,
- .bdrv_co_readv = bdrv_qed_co_readv,
- .bdrv_co_writev = bdrv_qed_co_writev,
- .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes,
- .bdrv_co_truncate = bdrv_qed_co_truncate,
- .bdrv_co_getlength = bdrv_qed_co_getlength,
- .bdrv_co_get_info = bdrv_qed_co_get_info,
- .bdrv_refresh_limits = bdrv_qed_refresh_limits,
- .bdrv_change_backing_file = bdrv_qed_change_backing_file,
- .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache,
- .bdrv_co_check = bdrv_qed_co_check,
- .bdrv_detach_aio_context = bdrv_qed_detach_aio_context,
- .bdrv_attach_aio_context = bdrv_qed_attach_aio_context,
- .bdrv_drain_begin = bdrv_qed_drain_begin,
+ .bdrv_probe = bdrv_qed_probe,
+ .bdrv_open = bdrv_qed_open,
+ .bdrv_close = bdrv_qed_close,
+ .bdrv_reopen_prepare = bdrv_qed_reopen_prepare,
+ .bdrv_child_perm = bdrv_default_perms,
+ .bdrv_co_create = bdrv_qed_co_create,
+ .bdrv_co_create_opts = bdrv_qed_co_create_opts,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
+ .bdrv_co_block_status = bdrv_qed_co_block_status,
+ .bdrv_co_readv = bdrv_qed_co_readv,
+ .bdrv_co_writev = bdrv_qed_co_writev,
+ .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes,
+ .bdrv_co_truncate = bdrv_qed_co_truncate,
+ .bdrv_co_getlength = bdrv_qed_co_getlength,
+ .bdrv_co_get_info = bdrv_qed_co_get_info,
+ .bdrv_refresh_limits = bdrv_qed_refresh_limits,
+ .bdrv_co_change_backing_file = bdrv_qed_co_change_backing_file,
+ .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache,
+ .bdrv_co_check = bdrv_qed_co_check,
+ .bdrv_detach_aio_context = bdrv_qed_detach_aio_context,
+ .bdrv_attach_aio_context = bdrv_qed_attach_aio_context,
+ .bdrv_drain_begin = bdrv_qed_drain_begin,
};
static void bdrv_qed_init(void)
diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h
index 9e0ccc1..6b21fbc 100644
--- a/include/block/block-global-state.h
+++ b/include/block/block-global-state.h
@@ -142,8 +142,7 @@
int bdrv_commit(BlockDriverState *bs);
int GRAPH_RDLOCK bdrv_make_empty(BdrvChild *c, Error **errp);
-int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
- const char *backing_fmt, bool warn);
+
void bdrv_register(BlockDriver *bdrv);
int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
const char *backing_file_str);
diff --git a/include/block/block-io.h b/include/block/block-io.h
index 58c4cf5..f8729cc 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -210,6 +210,14 @@
void bdrv_get_backing_filename(BlockDriverState *bs,
char *filename, int filename_size);
+int coroutine_fn GRAPH_RDLOCK
+bdrv_co_change_backing_file(BlockDriverState *bs, const char *backing_file,
+ const char *backing_fmt, bool warn);
+
+int co_wrapper_bdrv_rdlock
+bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
+ const char *backing_fmt, bool warn);
+
int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
int64_t pos, int size);
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index ed60669..59f6d7f 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -331,8 +331,9 @@
const char *name,
Error **errp);
- int (*bdrv_change_backing_file)(BlockDriverState *bs,
- const char *backing_file, const char *backing_fmt);
+ int coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_change_backing_file)(
+ BlockDriverState *bs, const char *backing_file,
+ const char *backing_fmt);
/* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
diff --git a/tests/unit/test-bdrv-drain.c b/tests/unit/test-bdrv-drain.c
index ba4e42b..8d05538 100644
--- a/tests/unit/test-bdrv-drain.c
+++ b/tests/unit/test-bdrv-drain.c
@@ -96,9 +96,9 @@
return 0;
}
-static int bdrv_test_change_backing_file(BlockDriverState *bs,
- const char *backing_file,
- const char *backing_fmt)
+static int bdrv_test_co_change_backing_file(BlockDriverState *bs,
+ const char *backing_file,
+ const char *backing_fmt)
{
return 0;
}
@@ -116,7 +116,7 @@
.bdrv_child_perm = bdrv_default_perms,
- .bdrv_change_backing_file = bdrv_test_change_backing_file,
+ .bdrv_co_change_backing_file = bdrv_test_co_change_backing_file,
};
static void aio_ret_cb(void *opaque, int ret)
