Record the features values for each rbd image and each of its
snapshots. This is really something that only becomes meaningful
for version 2 images, so this is just putting in place code
that will form common infrastructure.
It may be useful to expand the sysfs entries--and therefore the
information we maintain--for the image and for each snapshot.
But I'm going to hold off doing that until we start making
active use of the feature bits.
Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-rbd | 7 +++++
drivers/block/rbd.c | 43
+++++++++++++++++++++++++++++--
2 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-rbd
b/Documentation/ABI/testing/sysfs-bus-rbd
index 6fe4224..1cf2adf 100644
--- a/Documentation/ABI/testing/sysfs-bus-rbd
+++ b/Documentation/ABI/testing/sysfs-bus-rbd
@@ -25,6 +25,10 @@ client_id
The ceph unique client id that was assigned for this specific session.
+features
+
+ A hexadecimal encoding of the feature bits for this image.
+
major
The block device major number.
@@ -78,4 +82,7 @@ snap_size
The size of the image when this snapshot was taken.
+snap_features
+
+ A hexadecimal encoding of the feature bits for this snapshot.
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 2b048e3..c62d3f4 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -85,6 +85,7 @@
struct rbd_image_header {
/* These four fields never change for a given rbd image */
char *object_prefix;
+ u64 features;
__u8 obj_order;
__u8 crypt_type;
__u8 comp_type;
@@ -148,12 +149,14 @@ struct rbd_snap {
u64 size;
struct list_head node;
u64 id;
+ u64 features;
};
struct rbd_mapping {
char *snap_name;
u64 snap_id;
u64 size;
+ u64 features;
bool snap_exists;
bool read_only;
};
@@ -590,6 +593,7 @@ static int rbd_header_from_disk(struct
rbd_image_header *header,
header->snap_sizes = NULL;
}
+ header->features = 0; /* No features support in v1 images */
header->obj_order = ondisk->options.order;
header->crypt_type = ondisk->options.crypt_type;
header->comp_type = ondisk->options.comp_type;
@@ -632,6 +636,7 @@ static int snap_by_name(struct rbd_device *rbd_dev,
const char *snap_name)
if (!strcmp(snap_name, snap->name)) {
rbd_dev->mapping.snap_id = snap->id;
rbd_dev->mapping.size = snap->size;
+ rbd_dev->mapping.features = snap->features;
return 0;
}
@@ -648,6 +653,7 @@ static int rbd_dev_set_mapping(struct rbd_device
*rbd_dev, char *snap_name)
sizeof (RBD_SNAP_HEAD_NAME))) {
rbd_dev->mapping.snap_id = CEPH_NOSNAP;
rbd_dev->mapping.size = rbd_dev->header.image_size;
+ rbd_dev->mapping.features = rbd_dev->header.features;
rbd_dev->mapping.snap_exists = false;
rbd_dev->mapping.read_only = rbd_dev->rbd_opts.read_only;
ret = 0;
@@ -1835,6 +1841,19 @@ static ssize_t rbd_size_show(struct device *dev,
return sprintf(buf, "%llu\n", (unsigned long long) size * SECTOR_SIZE);
}
+/*
+ * Note this shows the features for whatever's mapped, which is not
+ * necessarily the base image.
+ */
+static ssize_t rbd_features_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "0x%016llx\n",
+ (unsigned long long) rbd_dev->mapping.features);
+}
+
static ssize_t rbd_major_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1884,6 +1903,10 @@ static ssize_t rbd_image_id_show(struct device *dev,
return sprintf(buf, "%s\n", rbd_dev->image_id);
}
+/*
+ * Shows the name of the currently-mapped snapshot (or
+ * RBD_SNAP_HEAD_NAME for the base image).
+ */
static ssize_t rbd_snap_show(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -1907,6 +1930,7 @@ static ssize_t rbd_image_refresh(struct device *dev,
}
static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
+static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
@@ -1918,6 +1942,7 @@ static DEVICE_ATTR(current_snap, S_IRUGO,
rbd_snap_show, NULL);
static struct attribute *rbd_attrs[] = {
&dev_attr_size.attr,
+ &dev_attr_features.attr,
&dev_attr_major.attr,
&dev_attr_client_id.attr,
&dev_attr_pool.attr,
@@ -1971,12 +1996,24 @@ static ssize_t rbd_snap_id_show(struct device *dev,
return sprintf(buf, "%llu\n", (unsigned long long)snap->id);
}
+static ssize_t rbd_snap_features_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev);
+
+ return sprintf(buf, "0x%016llx\n",
+ (unsigned long long) snap->features);
+}
+
static DEVICE_ATTR(snap_size, S_IRUGO, rbd_snap_size_show, NULL);
static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
+static DEVICE_ATTR(snap_features, S_IRUGO, rbd_snap_features_show, NULL);
static struct attribute *rbd_snap_attrs[] = {
&dev_attr_snap_size.attr,
&dev_attr_snap_id.attr,
+ &dev_attr_snap_features.attr,
NULL,
};
@@ -2032,7 +2069,8 @@ static int rbd_register_snap_dev(struct rbd_snap
*snap,
static struct rbd_snap *__rbd_add_snap_dev(struct rbd_device *rbd_dev,
const char *snap_name,
- u64 snap_id, u64 snap_size)
+ u64 snap_id, u64 snap_size,
+ u64 snap_features)
{
struct rbd_snap *snap;
int ret;
@@ -2048,6 +2086,7 @@ static struct rbd_snap *__rbd_add_snap_dev(struct
rbd_device *rbd_dev,
snap->id = snap_id;
snap->size = snap_size;
+ snap->features = snap_features;
return snap;
@@ -2118,7 +2157,7 @@ static int rbd_dev_snaps_update(struct rbd_device
*rbd_dev)
/* We haven't seen this snapshot before */
new_snap = __rbd_add_snap_dev(rbd_dev, snap_name,
- snap_id, header->snap_sizes[index]);
+ snap_id, header->snap_sizes[index], 0);
if (IS_ERR(new_snap)) {
int err = PTR_ERR(new_snap);
