rbd: add an rbd features field

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@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder 2012-07-13 20:35:12 -05:00
parent c8d184250d
commit 34b131849f
2 changed files with 48 additions and 2 deletions

View File

@ -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.

View File

@ -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,
};
@ -2037,7 +2074,8 @@ 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;
@ -2053,6 +2091,7 @@ 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;
@ -2123,7 +2162,7 @@ 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);