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[Qemu-devel] [PATCH v12 06/11] block: Add backing_blocker in BlockDriver
From: |
Fam Zheng |
Subject: |
[Qemu-devel] [PATCH v12 06/11] block: Add backing_blocker in BlockDriverState |
Date: |
Mon, 27 Jan 2014 11:48:12 +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 | 18 ++++++++++++++----
include/block/block_int.h | 3 +++
2 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/block.c b/block.c
index af8922b..4498ce7 100644
--- a/block.c
+++ b/block.c
@@ -1075,13 +1075,22 @@ 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);
bdrv_unref(bs->backing_hd);
+ } 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) {
bs->backing_file[0] = '\0';
bs->backing_format[0] = '\0';
+ if (error_is_set(&bs->backing_blocker)) {
+ error_free(bs->backing_blocker);
+ }
goto out;
}
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
@@ -1089,6 +1098,10 @@ void bdrv_set_backing_hd(BlockDriverState *bs,
BlockDriverState *backing_hd)
backing_hd->drv ? backing_hd->drv->format_name : "");
bdrv_ref(bs->backing_hd);
+ 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);
pstrcpy(bs->backing_file, sizeof(bs->backing_file),
bs->backing_hd->file->filename);
pstrcpy(bs->backing_format, sizeof(bs->backing_format),
@@ -1680,8 +1693,7 @@ void bdrv_close(BlockDriverState *bs)
if (bs->drv) {
if (bs->backing_hd) {
- bdrv_unref(bs->backing_hd);
- bs->backing_hd = NULL;
+ bdrv_set_backing_hd(bs, NULL);
}
bs->drv->bdrv_close(bs);
g_free(bs->opaque);
@@ -1883,7 +1895,6 @@ 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));
@@ -1902,7 +1913,6 @@ 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/include/block/block_int.h b/include/block/block_int.h
index 1d3f76f..1f4f78b 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -369,6 +369,9 @@ 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);
--
1.8.5.3
- [Qemu-devel] [PATCH v12 00/11] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD, Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 01/11] block: Add BlockOpType enum, Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 02/11] block: Introduce op_blockers to BlockDriverState, Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 03/11] block: Replace in_use with operation blocker, Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 04/11] block: Move op_blocker check from block_job_create to its caller, Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 05/11] block: Add bdrv_set_backing_hd(), Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 06/11] block: Add backing_blocker in BlockDriverState,
Fam Zheng <=
- [Qemu-devel] [PATCH v12 07/11] block: Parse "backing" option to reference existing BDS, Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 08/11] block: Support dropping active in bdrv_drop_intermediate, Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 09/11] stream: Use bdrv_drop_intermediate and drop close_unused_images, Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 10/11] qmp: Add command 'blockdev-backup', Fam Zheng, 2014/01/26
- [Qemu-devel] [PATCH v12 11/11] block: Allow backup on referenced named BlockDriverState, Fam Zheng, 2014/01/26
- Re: [Qemu-devel] [PATCH v12 00/11] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD, Stefan Hajnoczi, 2014/01/28
- Re: [Qemu-devel] [PATCH v12 00/11] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD, Fam Zheng, 2014/01/28