block: Parse 'detect-zeroes' in bdrv_open_common()
Amongst others, this means that you can now use the 'detect-zeroes'
option for non-top-level nodes in blockdev-add, like the QAPI schema
promises.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
diff --git a/block.c b/block.c
index 493ecf3..1f10457 100644
--- a/block.c
+++ b/block.c
@@ -42,6 +42,7 @@
#include "qapi-event.h"
#include "qemu/cutils.h"
#include "qemu/id.h"
+#include "qapi/util.h"
#ifdef CONFIG_BSD
#include <sys/ioctl.h>
@@ -954,6 +955,11 @@
.type = QEMU_OPT_BOOL,
.help = "Node is opened in read-only mode",
},
+ {
+ .name = "detect-zeroes",
+ .type = QEMU_OPT_STRING,
+ .help = "try to optimize zero writes (off, on, unmap)",
+ },
{ /* end of list */ }
},
};
@@ -970,6 +976,7 @@
const char *filename;
const char *driver_name = NULL;
const char *node_name = NULL;
+ const char *detect_zeroes;
QemuOpts *opts;
BlockDriver *drv;
Error *local_err = NULL;
@@ -1038,6 +1045,32 @@
}
}
+ detect_zeroes = qemu_opt_get(opts, "detect-zeroes");
+ if (detect_zeroes) {
+ BlockdevDetectZeroesOptions value =
+ qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
+ detect_zeroes,
+ BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX,
+ BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
+ &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ ret = -EINVAL;
+ goto fail_opts;
+ }
+
+ if (value == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
+ !(bs->open_flags & BDRV_O_UNMAP))
+ {
+ error_setg(errp, "setting detect-zeroes to unmap is not allowed "
+ "without setting discard operation to unmap");
+ ret = -EINVAL;
+ goto fail_opts;
+ }
+
+ bs->detect_zeroes = value;
+ }
+
if (filename != NULL) {
pstrcpy(bs->filename, sizeof(bs->filename), filename);
} else {
