block: add bdrv_co_delete_file_noerr

This function wraps bdrv_co_delete_file for the common case of removing a file,
which was just created by format driver, on an error condition.

It hides the -ENOTSUPP error, and reports all other errors otherwise.

Use it in luks driver

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20201217170904.946013-3-mlevitsk@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

@@ -706,6 +706,28 @@ int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp)
     return ret;
 }
 
+void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs)
+{
+    Error *local_err = NULL;
+    int ret;
+
+    if (!bs) {
+        return;
+    }
+
+    ret = bdrv_co_delete_file(bs, &local_err);
+    /*
+     * ENOTSUP will happen if the block driver doesn't support
+     * the 'bdrv_co_delete_file' interface. This is a predictable
+     * scenario and shouldn't be reported back to the user.
+     */
+    if (ret == -ENOTSUP) {
+        error_free(local_err);
+    } else if (ret < 0) {
+        error_report_err(local_err);
+    }
+}
+
 /**
  * Try to get @bs's logical and physical block size.
  * On success, store them in @bsz struct and return 0.

block/crypto.c

@@ -725,19 +725,8 @@ fail:
      * If an error occurred, delete 'filename'. Even if the file existed
      * beforehand, it has been truncated and corrupted in the process.
      */
-    if (ret && bs) {
+    if (ret) {
-        Error *local_delete_err = NULL;
+        bdrv_co_delete_file_noerr(bs);
-        int r_del = bdrv_co_delete_file(bs, &local_delete_err);
-        /*
-         * ENOTSUP will happen if the block driver doesn't support
-         * the 'bdrv_co_delete_file' interface. This is a predictable
-         * scenario and shouldn't be reported back to the user.
-         */
-        if ((r_del < 0) && (r_del != -ENOTSUP)) {
-            error_report_err(local_delete_err);
-        } else {
-            error_free(local_delete_err);
-        }
     }
 
     bdrv_unref(bs);

include/block/block.h

@@ -441,6 +441,7 @@ 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);
+void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs);
 
 
 typedef struct BdrvCheckResult {