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 14/35] block/copy-before-write: use file child instead of backing
Date: Thu, 10 Jun 2021 14:25:57 +0300 [thread overview]
Message-ID: <20210610112618.127378-15-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20210610112618.127378-1-vsementsov@virtuozzo.com>
We are going to publish copy-before-write filter, and there no public
backing-child-based filter in Qemu. No reason to create a precedent, so
let's refactor copy-before-write filter instead.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
block/copy-before-write.c | 39 ++++++++++++++++++++++-----------------
1 file changed, 22 insertions(+), 17 deletions(-)
diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index 945d9340f4..7a6c15f141 100644
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -43,7 +43,7 @@ static coroutine_fn int cbw_co_preadv(
BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
- return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
+ return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
}
static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs,
@@ -71,7 +71,7 @@ static int coroutine_fn cbw_co_pdiscard(BlockDriverState *bs,
return ret;
}
- return bdrv_co_pdiscard(bs->backing, offset, bytes);
+ return bdrv_co_pdiscard(bs->file, offset, bytes);
}
static int coroutine_fn cbw_co_pwrite_zeroes(BlockDriverState *bs,
@@ -82,7 +82,7 @@ static int coroutine_fn cbw_co_pwrite_zeroes(BlockDriverState *bs,
return ret;
}
- return bdrv_co_pwrite_zeroes(bs->backing, offset, bytes, flags);
+ return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
}
static coroutine_fn int cbw_co_pwritev(BlockDriverState *bs,
@@ -95,29 +95,22 @@ static coroutine_fn int cbw_co_pwritev(BlockDriverState *bs,
return ret;
}
- return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags);
+ return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
}
static int coroutine_fn cbw_co_flush(BlockDriverState *bs)
{
- if (!bs->backing) {
+ if (!bs->file) {
return 0;
}
- return bdrv_co_flush(bs->backing->bs);
+ return bdrv_co_flush(bs->file->bs);
}
static void cbw_refresh_filename(BlockDriverState *bs)
{
- if (bs->backing == NULL) {
- /*
- * we can be here after failed bdrv_attach_child in
- * bdrv_set_backing_hd
- */
- return;
- }
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
- bs->backing->bs->filename);
+ bs->file->bs->filename);
}
static void cbw_child_perm(BlockDriverState *bs, BdrvChild *c,
@@ -186,6 +179,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
top = bdrv_new_open_driver(&bdrv_cbw_filter, filter_node_name,
BDRV_O_RDWR, errp);
if (!top) {
+ error_prepend(errp, "Cannot open driver: ");
return NULL;
}
@@ -201,21 +195,32 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
state->target = bdrv_attach_child(top, target, "target", &child_of_bds,
BDRV_CHILD_DATA, errp);
if (!state->target) {
+ error_prepend(errp, "Cannot attach target child: ");
+ bdrv_unref(top);
+ return NULL;
+ }
+
+ bdrv_ref(source);
+ top->file = bdrv_attach_child(top, source, "file", &child_of_bds,
+ BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
+ errp);
+ if (!top->file) {
+ error_prepend(errp, "Cannot attach file child: ");
bdrv_unref(top);
return NULL;
}
bdrv_drained_begin(source);
- ret = bdrv_append(top, source, errp);
+ 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->backing, state->target,
- false, compress, errp);
+ state->bcs = block_copy_state_new(top->file, state->target, false, compress,
+ errp);
if (!state->bcs) {
error_prepend(errp, "Cannot create block-copy-state: ");
goto fail;
--
2.29.2
next prev parent reply other threads:[~2021-06-10 11:41 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 ` Vladimir Sementsov-Ogievskiy [this message]
2021-06-10 11:25 ` [PATCH v5 15/35] block/copy-before-write: bdrv_cbw_append(): replace child at last Vladimir Sementsov-Ogievskiy
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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