From: Sam Li <faithilikerun@xxxxxxxxx>
Putting zoned/non-zoned BlockDrivers on top of each other is not
allowed.
Signed-off-by: Sam Li <faithilikerun@xxxxxxxxx>
Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@xxxxxxx>
Acked-by: Kevin Wolf <kwolf@xxxxxxxxxx>
Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Message-id: 20230427172019.3345-6-faithilikerun@xxxxxxxxx
Message-id: 20230324090605.28361-6-faithilikerun@xxxxxxxxx
[Adjust commit message prefix as suggested by Philippe Mathieu-Daudé
<philmd@xxxxxxxxxx> and clarify that the check is about zoned
BlockDrivers.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
---
include/block/block_int-common.h | 5 +++++
block.c | 19 +++++++++++++++++++
block/file-posix.c | 12 ++++++++++++
block/raw-format.c | 1 +
4 files changed, 37 insertions(+)
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 997d539890..3482cfa79e 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -137,6 +137,11 @@ struct BlockDriver {
*/
bool is_format;
+ /*
+ * Set to true if the BlockDriver supports zoned children.
+ */
+ bool supports_zoned_children;
+
/*
* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
* this field set to true, except ones that are defined only by their
diff --git a/block.c b/block.c
index 5ec1a3897e..f67317c2b9 100644
--- a/block.c
+++ b/block.c
@@ -7967,6 +7967,25 @@ void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs,
return;
}
+ /*
+ * Non-zoned block drivers do not follow zoned storage constraints
+ * (i.e. sequential writes to zones). Refuse mixing zoned and non-zoned
+ * drivers in a graph.
+ */
+ if (!parent_bs->drv->supports_zoned_children &&
+ child_bs->bl.zoned == BLK_Z_HM) {
+ /*
+ * The host-aware model allows zoned storage constraints and random
+ * write. Allow mixing host-aware and non-zoned drivers. Using
+ * host-aware device as a regular device.
+ */
+ error_setg(errp, "Cannot add a %s child to a %s parent",
+ child_bs->bl.zoned == BLK_Z_HM ? "zoned" : "non-zoned",
+ parent_bs->drv->supports_zoned_children ?
+ "support zoned children" : "not support zoned children");
+ return;
+ }
+
if (!QLIST_EMPTY(&child_bs->parents)) {
error_setg(errp, "The node %s already has a parent",
child_bs->node_name);
diff --git a/block/file-posix.c b/block/file-posix.c
index 3b6575d771..67d4ec6ac5 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -776,6 +776,18 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
goto fail;
}
}
+#ifdef CONFIG_BLKZONED
+ /*
+ * The kernel page cache does not reliably work for writes to SWR zones
+ * of zoned block device because it can not guarantee the order of writes.
+ */
+ if ((bs->bl.zoned != BLK_Z_NONE) &&
+ (!(s->open_flags & O_DIRECT))) {
+ error_setg(errp, "The driver supports zoned devices, and it requires "
+ "cache.direct=on, which was not specified.");
+ return -EINVAL; /* No host kernel page cache */
+ }
+#endif
if (S_ISBLK(st.st_mode)) {
#ifdef __linux__
diff --git a/block/raw-format.c b/block/raw-format.c
index f167448462..1a1dce8da4 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -623,6 +623,7 @@ static void raw_child_perm(BlockDriverState *bs, BdrvChild *c,
BlockDriver bdrv_raw = {
.format_name = "raw",
.instance_size = sizeof(BDRVRawState),
+ .supports_zoned_children = true,
.bdrv_probe = &raw_probe,
.bdrv_reopen_prepare = &raw_reopen_prepare,
.bdrv_reopen_commit = &raw_reopen_commit,
--
2.40.0
