[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden |
Date: |
Mon, 5 Feb 2018 16:18:12 +0100 |
If the backing file is overridden, this most probably does change the
guest-visible data of a BDS. Therefore, we will need to consider this in
bdrv_refresh_filename().
Adding a new field to the BDS is not nice, but it is very simple and
exactly keeps track of whether the backing file has been overridden.
This commit adds a FIXME which will be remedied by a follow-up commit.
Until then, the respective piece of code will not result in any behavior
that is worse than what we currently have.
Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Reviewed-by: Alberto Garcia <address@hidden>
---
include/block/block_int.h | 1 +
block.c | 13 +++++++++++++
block/mirror.c | 4 ++++
blockdev.c | 16 ++++++++++++++++
4 files changed, 34 insertions(+)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 29cafa4236..b5c124fcbd 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -619,6 +619,7 @@ struct BlockDriverState {
char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
this file image */
char backing_format[16]; /* if non-zero and backing_file exists */
+ bool backing_overridden; /* backing file has been specified by the user */
QDict *full_open_options;
char exact_filename[PATH_MAX];
diff --git a/block.c b/block.c
index b84aba2d95..66e37219b9 100644
--- a/block.c
+++ b/block.c
@@ -2268,6 +2268,11 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict
*parent_options,
reference = qdict_get_try_str(parent_options, bdref_key);
if (reference || qdict_haskey(options, "file.filename")) {
backing_filename[0] = '\0';
+
+ /* FIXME: Should also be set to true if @options contains other runtime
+ * options which control the data that is read from the backing
+ * BDS */
+ bs->backing_overridden = true;
} else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
QDECREF(options);
goto free_exit;
@@ -2469,6 +2474,9 @@ static BlockDriverState
*bdrv_append_temp_snapshot(BlockDriverState *bs,
goto out;
}
+ bs_snapshot->backing_overridden = true;
+ bdrv_refresh_filename(bs_snapshot);
+
out:
QDECREF(snapshot_options);
g_free(tmp_filename);
@@ -2599,6 +2607,7 @@ static BlockDriverState *bdrv_open_inherit(const char
*filename,
backing = qdict_get_try_str(options, "backing");
if (backing && *backing == '\0') {
flags |= BDRV_O_NO_BACKING;
+ bs->backing_overridden = true;
qdict_del(options, "backing");
}
@@ -5031,6 +5040,10 @@ void bdrv_refresh_filename(BlockDriverState *bs)
* refresh those first */
QLIST_FOREACH(child, &bs->children, next) {
bdrv_refresh_filename(child->bs);
+
+ if (child->role == &child_backing && child->bs->backing_overridden) {
+ bs->backing_overridden = true;
+ }
}
if (drv->bdrv_refresh_filename) {
diff --git a/block/mirror.c b/block/mirror.c
index 5a627ba589..aa68531352 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -530,6 +530,10 @@ static void mirror_exit(BlockJob *job, void *opaque)
error_report_err(local_err);
data->ret = -EPERM;
}
+
+ /* The target image's file already has been created with the backing
+ * file we just set, so there is no need to set backing_overridden or
+ * call bdrv_refresh_filename(). */
}
if (s->to_replace) {
diff --git a/blockdev.c b/blockdev.c
index 8e977eef11..bbe264c3c0 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1795,6 +1795,8 @@ static void external_snapshot_commit(BlkActionState
*common)
{
ExternalSnapshotState *state =
DO_UPCAST(ExternalSnapshotState, common, common);
+ TransactionAction *action = common->action;
+ bool image_was_existing = false;
AioContext *aio_context;
aio_context = bdrv_get_aio_context(state->old_bs);
@@ -1808,6 +1810,20 @@ static void external_snapshot_commit(BlkActionState
*common)
NULL);
}
+ if (action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) {
+ BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
+ if (s->has_mode && s->mode == NEW_IMAGE_MODE_EXISTING) {
+ image_was_existing = true;
+ }
+ } else {
+ image_was_existing = true;
+ }
+
+ if (image_was_existing) {
+ state->new_bs->backing_overridden = true;
+ bdrv_refresh_filename(state->new_bs);
+ }
+
aio_context_release(aio_context);
}
--
2.14.3
- [Qemu-devel] [PATCH v8 00/26] block: Fix some filename generation issues, Max Reitz, 2018/02/05
- [Qemu-devel] [PATCH v8 01/26] block/mirror: Small absolute-paths simplification, Max Reitz, 2018/02/05
- [Qemu-devel] [PATCH v8 02/26] block: Use children list in bdrv_refresh_filename, Max Reitz, 2018/02/05
- [Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden,
Max Reitz <=
- Re: [Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden, Kevin Wolf, 2018/02/22
- Re: [Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden, Max Reitz, 2018/02/22
- Re: [Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden, Kevin Wolf, 2018/02/22
- Re: [Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden, Max Reitz, 2018/02/22
- Re: [Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden, Kevin Wolf, 2018/02/22
- Re: [Qemu-devel] [PATCH v8 03/26] block: Add BDS.backing_overridden, Max Reitz, 2018/02/22
[Qemu-devel] [PATCH v8 04/26] iotests: Drop explicit base blockdev in 191, Max Reitz, 2018/02/05