On 2013-10-02 14:33, Benoît Canet wrote:
This field is used by blkverify to disable external snapshots creation.
I will also be used by block filters like quorum to disable external snapshots
creation.
Signed-off-by: Benoit Canet <ben...@irqsave.net>
---
block.c | 17 +++++++++++++++++
block/blkverify.c | 2 ++
blockdev.c | 5 +++++
include/block/block.h | 14 ++++++++++++++
include/block/block_int.h | 6 ++++++
5 files changed, 44 insertions(+)
diff --git a/block.c b/block.c
index 93e113a..e891522 100644
--- a/block.c
+++ b/block.c
@@ -4632,3 +4632,20 @@ int bdrv_amend_options(BlockDriverState *bs,
QEMUOptionParameter *options)
}
return bs->drv->bdrv_amend_options(bs, options);
}
+
+ExtSnapshotPerm bdrv_check_ext_snapshot(BlockDriverState *bs)
+{
+ /* external snashots are allowed by defaults */
I don't really know whether it should rather be "by default", but it
certainly should be s/snashots/snapshots/. ;)
Also, I'd move this comment below the if statements and above the return
EXT_SNAPSHOT_ALLOWED.
+ if (bs->drv->bdrv_check_ext_snapshot) {
+ return bs->drv->bdrv_check_ext_snapshot(bs);
+ }
+ if (bs->file && bs->file->drv && bs->file->drv->bdrv_check_ext_snapshot) {
+ return bs->file->drv->bdrv_check_ext_snapshot(bs);
+ }
+ return EXT_SNAPSHOT_ALLOWED;
+}
+
+ExtSnapshotPerm bdrv_check_ext_snapshot_forbidden(BlockDriverState *bs)
+{
+ return EXT_SNAPSHOT_FORBIDDEN;
+}
diff --git a/block/blkverify.c b/block/blkverify.c
index 2077d8a..b64c638 100644
--- a/block/blkverify.c
+++ b/block/blkverify.c
@@ -313,6 +313,8 @@ static BlockDriver bdrv_blkverify = {
.bdrv_aio_readv = blkverify_aio_readv,
.bdrv_aio_writev = blkverify_aio_writev,
.bdrv_aio_flush = blkverify_aio_flush,
+
+ .bdrv_check_ext_snapshot = bdrv_check_ext_snapshot_forbidden,
};
static void bdrv_blkverify_init(void)
diff --git a/blockdev.c b/blockdev.c
index 8aa66a9..92029d8 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1131,6 +1131,11 @@ static void
external_snapshot_prepare(BlkTransactionState *common,
}
}
+ if (bdrv_check_ext_snapshot(state->old_bs) != EXT_SNAPSHOT_ALLOWED) {
+ error_set(errp, QERR_FEATURE_DISABLED, "snapshot");
+ return;
+ }
+
flags = state->old_bs->open_flags;
/* create new image w/backing file */
diff --git a/include/block/block.h b/include/block/block.h
index f808550..2bf0e12 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -244,6 +244,20 @@ int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix);
int bdrv_amend_options(BlockDriverState *bs_new, QEMUOptionParameter *options);
+/* external snapshots */
+
+typedef enum {
+ EXT_SNAPSHOT_ALLOWED,
+ EXT_SNAPSHOT_FORBIDDEN,
+} ExtSnapshotPerm;
+
+/* return EXT_SNAPSHOT_ALLOWED if external snapshot is allowed
+ * return EXT_SNAPSHOT_FORBIDEN if external snapshot is forbiden
s/FORBIDEN/FORBIDDEN/, s/forbiden/forbidden/
+ */
+ExtSnapshotPerm bdrv_check_ext_snapshot(BlockDriverState *bs);
+/* helper used to forbid external snapshots like in blkverify */
+ExtSnapshotPerm bdrv_check_ext_snapshot_forbidden(BlockDriverState *bs);
+
/* async block I/O */
typedef void BlockDriverDirtyHandler(BlockDriverState *bs, int64_t sector,
int sector_num);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 211087a..e6a14ae 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -67,6 +67,12 @@ typedef struct BdrvTrackedRequest {
struct BlockDriver {
const char *format_name;
int instance_size;
+
+ /* if not defined external snapshots are allowed
+ * future block filters will query their children to build the response
+ */
+ ExtSnapshotPerm (*bdrv_check_ext_snapshot)(BlockDriverState *bs);
+
int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
int (*bdrv_probe_device)(const char *filename);
Aside from the misspellings (and regardless of whether you decide to
move the comment or not):
Reviewed-by: Max Reitz <mre...@redhat.com>
