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From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, vsementsov@virtuozzo.com,
	jsnow@redhat.com, mreitz@redhat.com, kwolf@redhat.com
Subject: [PATCH v5 15/35] block/copy-before-write: bdrv_cbw_append(): replace child at last
Date: Thu, 10 Jun 2021 14:25:58 +0300	[thread overview]
Message-ID: <20210610112618.127378-16-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20210610112618.127378-1-vsementsov@virtuozzo.com>

Refactor the function to replace child at last. Thus we don't need to
revert it and code is simplified.

block-copy state initialization being done before replacing the child
doesn't need any drained section.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block/copy-before-write.c | 33 +++++++++++----------------------
 1 file changed, 11 insertions(+), 22 deletions(-)

diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index 7a6c15f141..adbbc64aa9 100644
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -172,7 +172,6 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
     int ret;
     BDRVCopyBeforeWriteState *state;
     BlockDriverState *top;
-    bool appended = false;
 
     assert(source->total_sectors == target->total_sectors);
 
@@ -196,8 +195,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
                                       BDRV_CHILD_DATA, errp);
     if (!state->target) {
         error_prepend(errp, "Cannot attach target child: ");
-        bdrv_unref(top);
-        return NULL;
+        goto fail;
     }
 
     bdrv_ref(source);
@@ -206,18 +204,8 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
                                   errp);
     if (!top->file) {
         error_prepend(errp, "Cannot attach file child: ");
-        bdrv_unref(top);
-        return NULL;
-    }
-
-    bdrv_drained_begin(source);
-
-    ret = bdrv_replace_node(source, top, errp);
-    if (ret < 0) {
-        error_prepend(errp, "Cannot append copy-before-write filter: ");
         goto fail;
     }
-    appended = true;
 
     state->bcs = block_copy_state_new(top->file, state->target, false, compress,
                                       errp);
@@ -225,21 +213,22 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
         error_prepend(errp, "Cannot create block-copy-state: ");
         goto fail;
     }
-    *bcs = state->bcs;
 
+    bdrv_drained_begin(source);
+    ret = bdrv_replace_node(source, top, errp);
     bdrv_drained_end(source);
+    if (ret < 0) {
+        error_prepend(errp, "Cannot append copy-before-write filter: ");
+        goto fail;
+    }
+
+    *bcs = state->bcs;
 
     return top;
 
 fail:
-    if (appended) {
-        bdrv_cbw_drop(top);
-    } else {
-        bdrv_unref(top);
-    }
-
-    bdrv_drained_end(source);
-
+    block_copy_state_free(state->bcs);
+    bdrv_unref(top);
     return NULL;
 }
 
-- 
2.29.2



  parent reply	other threads:[~2021-06-10 11:42 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-10 11:25 [PATCH v5 00/35] block: publish backup-top filter Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 01/35] block: rename bdrv_replace_child to bdrv_replace_child_tran Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 02/35] block: comment graph-modifying function not updating permissions Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 03/35] block: introduce bdrv_replace_child_bs() Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 04/35] block: introduce blk_replace_bs Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 05/35] qdev-properties: PropertyInfo: add realized_set_allowed field Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 06/35] qdev: allow setting drive property for realized device Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 07/35] block: rename backup-top to copy-before-write Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 08/35] block-copy: always set BDRV_REQ_SERIALISING flag Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 09/35] block/block-copy: introduce block_copy_set_copy_opts() Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 10/35] block/backup: set copy_range and compress after filter insertion Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 11/35] block/backup: move cluster size calculation to block-copy Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 12/35] block/copy-before-write: relax permission requirements when no parents Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 13/35] block/copy-before-write: drop extra bdrv_unref on failure path Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` [PATCH v5 14/35] block/copy-before-write: use file child instead of backing Vladimir Sementsov-Ogievskiy
2021-06-10 11:25 ` Vladimir Sementsov-Ogievskiy [this message]
2021-06-10 11:25 ` [PATCH v5 16/35] block/copy-before-write: introduce cbw_init() Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 17/35] block/copy-before-write: cbw_init(): rename variables Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 18/35] block/copy-before-write: cbw_init(): use file child after attaching Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 19/35] block/copy-before-write: bdrv_cbw_append(): drop unused compress arg Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 20/35] block/copy-before-write: cbw_init(): use options Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 21/35] block/copy-before-write: initialize block-copy bitmap Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 22/35] block/block-copy: make setting progress optional Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 23/35] block/copy-before-write: make public block driver Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 24/35] qapi: publish copy-before-write filter Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 25/35] python/qemu/machine.py: refactor _qemu_args() Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 26/35] python/qemu/machine: QEMUMachine: improve qmp() method Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 27/35] iotests.py: VM: add own __enter__ method Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 28/35] iotests/222: fix pylint and mypy complains Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 29/35] iotests/222: constantly use single quotes for strings Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 30/35] iotests: move 222 to tests/image-fleecing Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 31/35] iotests.py: hmp_qemu_io: support qdev Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 32/35] iotests/image-fleecing: proper source device Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 33/35] iotests/image-fleecing: rename tgt_node Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 34/35] iotests/image-fleecing: prepare for adding new test-case Vladimir Sementsov-Ogievskiy
2021-06-10 11:26 ` [PATCH v5 35/35] iotests/image-fleecing: add test-case for copy-before-write filter Vladimir Sementsov-Ogievskiy

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