@@ -800,6 +800,7 @@ 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_SHARE);
/* Inherit the read-only option from the parent if it's not set */
qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
@@ -908,6 +909,7 @@ 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_SHARE);
/* backing files always opened read-only */
qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on");
@@ -1152,6 +1154,11 @@ QemuOptsList bdrv_runtime_opts = {
.type = QEMU_OPT_STRING,
.help = "discard operation (ignore/off, unmap/on)",
},
+ {
+ .name = BDRV_OPT_FORCE_SHARE,
+ .type = QEMU_OPT_BOOL,
+ .help = "always accept other writers (default: off)",
+ },
{ /* end of list */ }
},
};
@@ -1191,6 +1198,16 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
drv = bdrv_find_format(driver_name);
assert(drv != NULL);
+ bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false);
+
+ if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) {
+ error_setg(errp,
+ BDRV_OPT_FORCE_SHARE
+ "=on can only be used with read-only images");
+ ret = -EINVAL;
+ goto fail_opts;
+ }
+
if (file != NULL) {
filename = blk_bs(file)->filename;
} else {
@@ -109,6 +109,7 @@ 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_SHARE "force-share"
#define BDRV_SECTOR_BITS 9
@@ -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_share; /* if true, always allow all shared permissions */
BlockDriver *drv; /* NULL means no media */
void *opaque;
@@ -2898,6 +2898,8 @@
# (default: false)
# @detect-zeroes: detect and optimize zero writes (Since 2.1)
# (default: off)
+# @force-share: force share all permission on added nodes.
+# Requires read-only=true. (Since 2.10)
#
# Remaining options are determined by the block driver.
#
@@ -2909,6 +2911,7 @@
'*discard': 'BlockdevDiscardOptions',
'*cache': 'BlockdevCacheOptions',
'*read-only': 'bool',
+ '*force-share': 'bool',
'*detect-zeroes': 'BlockdevDetectZeroesOptions' },
'discriminator': 'driver',
'data': {
Signed-off-by: Fam Zheng <famz@redhat.com> --- block.c | 17 +++++++++++++++++ include/block/block.h | 1 + include/block/block_int.h | 1 + qapi/block-core.json | 3 +++ 4 files changed, 22 insertions(+)