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[Qemu-devel] [PATCH v19 07/16] block: Add backing_blocker in BlockDriver
From: |
Fam Zheng |
Subject: |
[Qemu-devel] [PATCH v19 07/16] block: Add backing_blocker in BlockDriverState |
Date: |
Mon, 12 May 2014 09:35:46 +0800 |
This makes use of op_blocker and blocks all the operations except for
commit target, on each BlockDriverState->backing_hd.
The asserts for op_blocker in bdrv_swap are removed because with this
change, the target of block commit has at least the backing blocker of
its child, so the assertion is not true. Callers should do their check.
Signed-off-by: Fam Zheng <address@hidden>
---
block.c | 24 ++++++++++++++++++++----
block/mirror.c | 1 +
include/block/block_int.h | 3 +++
3 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/block.c b/block.c
index ec26a2b..8155e68 100644
--- a/block.c
+++ b/block.c
@@ -1097,14 +1097,31 @@ fail:
void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
{
+ if (bs->backing_hd) {
+ assert(error_is_set(&bs->backing_blocker));
+ bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker);
+ } else if (backing_hd) {
+ error_setg(&bs->backing_blocker,
+ "device is used as backing hd of '%s'",
+ bs->device_name);
+ }
+
bs->backing_hd = backing_hd;
if (!backing_hd) {
+ if (error_is_set(&bs->backing_blocker)) {
+ error_free(bs->backing_blocker);
+ }
goto out;
}
bs->open_flags &= ~BDRV_O_NO_BACKING;
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
pstrcpy(bs->backing_format, sizeof(bs->backing_format),
backing_hd->drv ? backing_hd->drv->format_name : "");
+
+ bdrv_op_block_all(bs->backing_hd, bs->backing_blocker);
+ /* Otherwise we won't be able to commit due to check in bdrv_commit */
+ bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT,
+ bs->backing_blocker);
out:
bdrv_refresh_limits(bs);
}
@@ -1758,8 +1775,9 @@ void bdrv_close(BlockDriverState *bs)
if (bs->drv) {
if (bs->backing_hd) {
- bdrv_unref(bs->backing_hd);
- bs->backing_hd = NULL;
+ BlockDriverState *backing_hd = bs->backing_hd;
+ bdrv_set_backing_hd(bs, NULL);
+ bdrv_unref(backing_hd);
}
bs->drv->bdrv_close(bs);
g_free(bs->opaque);
@@ -1961,7 +1979,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState
*bs_old)
assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
assert(bs_new->job == NULL);
assert(bs_new->dev == NULL);
- assert(bdrv_op_blocker_is_empty(bs_new));
assert(bs_new->io_limits_enabled == false);
assert(!throttle_have_timer(&bs_new->throttle_state));
@@ -1980,7 +1997,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState
*bs_old)
/* Check a few fields that should remain attached to the device */
assert(bs_new->dev == NULL);
assert(bs_new->job == NULL);
- assert(bdrv_op_blocker_is_empty(bs_new));
assert(bs_new->io_limits_enabled == false);
assert(!throttle_have_timer(&bs_new->throttle_state));
diff --git a/block/mirror.c b/block/mirror.c
index 1c38aa8..6a53d79 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -499,6 +499,7 @@ immediate_exit:
* trigger the unref from the top one */
BlockDriverState *p = s->base->backing_hd;
s->base->backing_hd = NULL;
+ bdrv_op_unblock_all(p, s->base->backing_blocker);
bdrv_unref(p);
}
}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 3518076..49e5824 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -368,6 +368,9 @@ struct BlockDriverState {
BlockJob *job;
QDict *options;
+
+ /* The error object in use for blocking operations on backing_hd */
+ Error *backing_blocker;
};
int get_tmp_filename(char *filename, int size);
--
1.9.2
[Qemu-devel] [PATCH v19 08/16] block: Parse "backing" option to reference existing BDS, Fam Zheng, 2014/05/11
[Qemu-devel] [PATCH v19 09/16] block: Support dropping active in bdrv_drop_intermediate, Fam Zheng, 2014/05/11
[Qemu-devel] [PATCH v19 10/16] stream: Use bdrv_drop_intermediate and drop close_unused_images, Fam Zheng, 2014/05/11
[Qemu-devel] [PATCH v19 11/16] commit: Use bdrv_drop_intermediate, Fam Zheng, 2014/05/11
[Qemu-devel] [PATCH v19 12/16] qmp: Add command 'blockdev-backup', Fam Zheng, 2014/05/11