[PULL 11/13] block.c: adding bdrv_co_delete_file

[Kevin Wolf]

From: Daniel Henrique Barboza <address@hidden>

Using the new 'bdrv_co_delete_file' interface, a pure co_routine function
'bdrv_co_delete_file' inside block.c can can be used in a way similar of
the existing bdrv_create_file to to clean up a created file.

We're creating a pure co_routine because the only caller of
'bdrv_co_delete_file' will be already in co_routine context, thus there
is no need to add all the machinery to check for qemu_in_coroutine() and
create a separated co_routine to do the job.

Suggested-by: Daniel P. Berrangé <address@hidden>
Signed-off-by: Daniel Henrique Barboza <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
 include/block/block.h |  1 +
 block.c               | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/include/block/block.h b/include/block/block.h
index cd6b5b95aa..e569a4d747 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -363,6 +363,7 @@ bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, 
BlockDriverState *base,
 int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
                               Error **errp);
 void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
+int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp);
 
 
 typedef struct BdrvCheckResult {
diff --git a/block.c b/block.c
index 8fc7b56937..a2542c977b 100644
--- a/block.c
+++ b/block.c
@@ -668,6 +668,32 @@ int bdrv_create_file(const char *filename, QemuOpts *opts, 
Error **errp)
     }
 }
 
+int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp)
+{
+    Error *local_err = NULL;
+    int ret;
+
+    assert(bs != NULL);
+
+    if (!bs->drv) {
+        error_setg(errp, "Block node '%s' is not opened", bs->filename);
+        return -ENOMEDIUM;
+    }
+
+    if (!bs->drv->bdrv_co_delete_file) {
+        error_setg(errp, "Driver '%s' does not support image deletion",
+                   bs->drv->format_name);
+        return -ENOTSUP;
+    }
+
+    ret = bs->drv->bdrv_co_delete_file(bs, &local_err);
+    if (ret < 0) {
+        error_propagate(errp, local_err);
+    }
+
+    return ret;
+}
+
 /**
  * Try to get @bs's logical and physical block size.
  * On success, store them in @bsz struct and return 0.
-- 
2.20.1