[3/9] rbd: refresh features and set the disk to readonly if there is unsupported bit

Commit Message

Dongsheng Yang May 7, 2018, 8:43 a.m. UTC

If there is unsupported feature enabled after rbd map, we will noticed it in
refreshing, then we need to set the disk readonly.

For example, if we enabled the object-map feature after rbd map, as we don't
support object-map in kernel rbd currently,  we should avoid user to write
rbd device. And set dist to read-write when we disable the unsupported features.

Signed-off-by: Dongsheng Yang <[e-mail]>
---
 drivers/block/rbd.c | 44 +++++++++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 19 deletions(-)

Patch

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index a1a4bbe..70ca81d 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -345,6 +345,7 @@  struct rbd_device {
 	unsigned long		flags;		/* possibly lock protected */
 	struct rbd_spec		*spec;
 	struct rbd_options	*opts;
+	bool			read_only_need_restore;
 	char			*config_info;	/* add{,_single_major} string */
 
 	struct ceph_object_id	header_oid;
@@ -4561,17 +4562,6 @@  static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
 	return 0;
 }
 
-static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
-{
-	u64 features = 0;
-	int ret = _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP, features);
-	if (ret)
-		return ret
-
-	rbd_dev->header.features = features
-	return 0;
-}
-
 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
 {
 	struct rbd_spec *parent_spec;
@@ -5036,12 +5026,35 @@  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) {
+			if (!rbd_dev->opts->read_only) {
+				rbd_dev->opts->read_only = true;
+				rbd_dev->read_only_need_restore = true;
+				set_disk_ro(rbd_dev->disk,
+						rbd_dev->opts->read_only);
+			}
+		} else {
+			return ret;
+		}
+	} else {
+		if (rbd_dev->read_only_need_restore) {
+			rbd_dev->opts->read_only = false;
+			rbd_dev->read_only_need_restore = false;
+			set_disk_ro(rbd_dev->disk, rbd_dev->opts->read_only);
+		}
+	}
+	rbd_dev->mapping.features = rbd_dev->header.features = features;
+
 	if (first_time) {
 		ret = rbd_dev_v2_header_onetime(rbd_dev);
 		if (ret)
@@ -5413,14 +5426,6 @@  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) {
@@ -5731,6 +5736,7 @@  static ssize_t do_rbd_add(struct bus_type *bus,
 		goto err_out_rbd_dev;
 	}
 
+	rbd_dev->read_only_need_restore = false;
 	/* If we are mapping a snapshot it must be marked read-only */
 	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
 		rbd_dev->opts->read_only = true;