On 11/18/2019 09:38 PM, Ilya Dryomov wrote:
For a read-only mapping, ask for a set of features that make the image
only unreadable, rather than both unreadable and unwritable by a client
that doesn't understand them. As of today, the difference between them
for krbd is journaling (JOURNALING) and live migration (MIGRATING).
get_features method supports read_only parameter since hammer, ceph.git
commit 6176ec5fde2a ("librbd: differentiate between R/O vs R/W RBD
features").
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Reviewed-by: Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx>
---
drivers/block/rbd.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 935b66808e40..b3167247c90a 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -5652,9 +5652,12 @@ static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
}
static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
- u64 *snap_features)
+ bool read_only, u64 *snap_features)
{
- __le64 snapid = cpu_to_le64(snap_id);
+ struct {
+ __le64 snap_id;
+ u8 read_only;
+ } features_in;
struct {
__le64 features;
__le64 incompat;
@@ -5662,9 +5665,12 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
u64 unsup;
int ret;
+ features_in.snap_id = cpu_to_le64(snap_id);
+ features_in.read_only = read_only;
+
ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
&rbd_dev->header_oloc, "get_features",
- &snapid, sizeof(snapid),
+ &features_in, sizeof(features_in),
&features_buf, sizeof(features_buf));
dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
if (ret < 0)
@@ -5692,7 +5698,8 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
{
return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
- &rbd_dev->header.features);
+ rbd_is_ro(rbd_dev),
+ &rbd_dev->header.features);
}
/*
