Signed-off-by: Fam Zheng <f...@redhat.com>
---
block.c | 9 +++++++++
include/block/block.h | 2 ++
include/block/block_int.h | 1 +
3 files changed, 12 insertions(+)
diff --git a/block.c b/block.c
index 1e668fb..f5c4e97 100644
--- a/block.c
+++ b/block.c
@@ -763,6 +763,7 @@ static void bdrv_inherited_options(int *child_flags, QDict
*child_options,
* the parent. */
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
+ qdict_copy_default(child_options, parent_options,
BDRV_OPT_FORCE_SHARED_WRITE);
/* Inherit the read-only option from the parent if it's not set */
qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
@@ -871,6 +872,7 @@ static void bdrv_backing_options(int *child_flags, QDict
*child_options,
* which is only applied on the top level (BlockBackend) */
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
+ qdict_copy_default(child_options, parent_options,
BDRV_OPT_FORCE_SHARED_WRITE);
/* backing files always opened read-only */
qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on");
@@ -1115,6 +1117,11 @@ QemuOptsList bdrv_runtime_opts = {
.type = QEMU_OPT_STRING,
.help = "discard operation (ignore/off, unmap/on)",
},
+ {
+ .name = BDRV_OPT_FORCE_SHARED_WRITE,
+ .type = QEMU_OPT_BOOL,
+ .help = "always accept other writers (default: off)",
+ },
{ /* end of list */ }
},
};
@@ -1154,6 +1161,8 @@ static int bdrv_open_common(BlockDriverState *bs,
BlockBackend *file,
drv = bdrv_find_format(driver_name);
assert(drv != NULL);
+ bs->force_shared_write = qemu_opt_get_bool(opts,
BDRV_OPT_FORCE_SHARED_WRITE, false);
+
if (file != NULL) {
filename = blk_bs(file)->filename;
} else {
diff --git a/include/block/block.h b/include/block/block.h
index 5ddc0cf..d3afb75 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -109,6 +109,8 @@ typedef struct HDGeometry {
#define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
#define BDRV_OPT_READ_ONLY "read-only"
#define BDRV_OPT_DISCARD "discard"
+#define BDRV_OPT_FORCE_SHARED_WRITE \
+ "force-shared-write"
#define BDRV_SECTOR_BITS 9
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 59400bd..fb81692 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -518,6 +518,7 @@ struct BlockDriverState {
bool valid_key; /* if true, a valid encryption key has been set */
bool sg; /* if true, the device is a /dev/sg* */
bool probed; /* if true, format was probed rather than specified */
+ bool force_shared_write; /* if true, always allow shared write perm. */
BlockDriver *drv; /* NULL means no media */
void *opaque;
--
2.9.3
