[PATCH] rbd: mark rbd disk to ro if we found feature unsupported enabled after mapping

[Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx>]

If there is unsupported feature enabled after rbd map, we will noticed it in
refreshing, then we need to set the disk readonly. In addition, we need to
set disk to rw if these unsupportted features disabled later.

Signed-off-by: Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx>
---
 drivers/block/rbd.c | 48 ++++++++++++++++++++++++------------------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 8e5140b..e911830 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3695,6 +3695,9 @@ static void rbd_queue_workfn(struct work_struct *work)
 		snapc = rbd_dev->header.snapc;
 		ceph_get_snap_context(snapc);
 	}
+	must_be_locked =
+	    (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
+	    (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);
 	up_read(&rbd_dev->header_rwsem);
 
 	if (offset + length > mapping_size) {
@@ -3704,9 +3707,6 @@ static void rbd_queue_workfn(struct work_struct *work)
 		goto err_rq;
 	}
 
-	must_be_locked =
-	    (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
-	    (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);
 	if (must_be_locked) {
 		down_read(&rbd_dev->lock_rwsem);
 		result = rbd_wait_state_locked(rbd_dev,
@@ -4567,13 +4567,6 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
 	if (ret < sizeof (features_buf))
 		return -ERANGE;
 
-	unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
-	if (unsup) {
-		rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
-			 unsup);
-		return -ENXIO;
-	}
-
 	*snap_features = le64_to_cpu(features_buf.features);
 
 	dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
@@ -4581,13 +4574,14 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
 		(unsigned long long)*snap_features,
 		(unsigned long long)le64_to_cpu(features_buf.incompat));
 
-	return 0;
-}
+	unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
+	if (unsup) {
+		rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
+			 unsup);
+		return -ENXIO;
+	}
 
-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);
+	return 0;
 }
 
 struct parent_image_info {
@@ -5184,12 +5178,26 @@ static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
 {
 	bool first_time = rbd_dev->header.object_prefix == NULL;
+	u64 features = 0;
 	int ret;
 
 	ret = rbd_dev_v2_image_size(rbd_dev);
 	if (ret)
 		return ret;
 
+	ret = _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
+					&features);
+	if (ret) {
+		if (-ENXIO == ret && !first_time)
+			set_disk_ro(rbd_dev->disk, true);
+		else
+			return ret;
+	} else {
+		if (!first_time && !rbd_dev->opts->read_only)
+			set_disk_ro(rbd_dev->disk, false);
+	}
+	rbd_dev->mapping.features = rbd_dev->header.features = features;
+
 	if (first_time) {
 		ret = rbd_dev_v2_header_onetime(rbd_dev);
 		if (ret)
@@ -5560,14 +5568,6 @@ static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
 	if (ret)
 		goto out_err;
 
-	/*
-	 * Get the and check features for the image.  Currently the
-	 * features are assumed to never change.
-	 */
-	ret = rbd_dev_v2_features(rbd_dev);
-	if (ret)
-		goto out_err;
-
 	/* If the image supports fancy striping, get its parameters */
 
 	if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
-- 
1.8.3.1