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rbd: probe the parent of an image if present

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Call the probe function for the parent device if one is present.
Since we don't formally support the layering feature we won't
be using this functionality just yet.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder 2012-10-30 19:40:33 -05:00 committed by Sage Weil
parent 6365d33a27
commit 2f82ee54d9
1 changed files with 76 additions and 5 deletions
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81
drivers/block/rbd.c
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@ -289,6 +289,7 @@ struct rbd_device {
struct rbd_spec *parent_spec;
u64 parent_overlap;
struct rbd_device *parent;
/* protects updating the header */
struct rw_semaphore header_rwsem;
@ -335,6 +336,7 @@ static ssize_t rbd_add(struct bus_type *bus, const char *buf,
size_t count);
static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
size_t count);
static int rbd_dev_probe(struct rbd_device *rbd_dev);
static struct bus_attribute rbd_bus_attrs[] = {
__ATTR(add, S_IWUSR, NULL, rbd_add),
@ -497,6 +499,13 @@ static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
return ERR_PTR(ret);
}
static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
{
kref_get(&rbdc->kref);
return rbdc;
}
/*
* Find a ceph client with specific addr and configuration. If
* found, bump its reference count.
@ -512,7 +521,8 @@ static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
spin_lock(&rbd_client_list_lock);
list_for_each_entry(client_node, &rbd_client_list, node) {
if (!ceph_compare_options(ceph_opts, client_node->client)) {
kref_get(&client_node->kref);
__rbd_get_client(client_node);
found = true;
break;
}
@ -2741,8 +2751,6 @@ static struct rbd_spec *rbd_spec_alloc(void)
return NULL;
kref_init(&spec->kref);
rbd_spec_put(rbd_spec_get(spec)); /* TEMPORARY */
return spec;
}
@ -3837,6 +3845,11 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
void *response;
void *p;
/* If we already have it we don't need to look it up */
if (rbd_dev->spec->image_id)
return 0;
/*
* When probing a parent image, the image id is already
* known (and the image name likely is not). There's no
@ -4014,6 +4027,9 @@ static int rbd_dev_v2_probe(struct rbd_device *rbd_dev)
static int rbd_dev_probe_finish(struct rbd_device *rbd_dev)
{
struct rbd_device *parent = NULL;
struct rbd_spec *parent_spec = NULL;
struct rbd_client *rbdc = NULL;
int ret;
/* no need to lock here, as rbd_dev is not registered yet */
@ -4058,6 +4074,31 @@ static int rbd_dev_probe_finish(struct rbd_device *rbd_dev)
* At this point cleanup in the event of an error is the job
* of the sysfs code (initiated by rbd_bus_del_dev()).
*/
/* Probe the parent if there is one */
if (rbd_dev->parent_spec) {
/*
* We need to pass a reference to the client and the
* parent spec when creating the parent rbd_dev.
* Images related by parent/child relationships
* always share both.
*/
parent_spec = rbd_spec_get(rbd_dev->parent_spec);
rbdc = __rbd_get_client(rbd_dev->rbd_client);
parent = rbd_dev_create(rbdc, parent_spec);
if (!parent) {
ret = -ENOMEM;
goto err_out_spec;
}
rbdc = NULL; /* parent now owns reference */
parent_spec = NULL; /* parent now owns reference */
ret = rbd_dev_probe(parent);
if (ret < 0)
goto err_out_parent;
rbd_dev->parent = parent;
}
down_write(&rbd_dev->header_rwsem);
ret = rbd_dev_snaps_register(rbd_dev);
up_write(&rbd_dev->header_rwsem);
@ -4076,6 +4117,12 @@ static int rbd_dev_probe_finish(struct rbd_device *rbd_dev)
(unsigned long long) rbd_dev->mapping.size);
return ret;
err_out_parent:
rbd_dev_destroy(parent);
err_out_spec:
rbd_spec_put(parent_spec);
rbd_put_client(rbdc);
err_out_bus:
/* this will also clean up rest of rbd_dev stuff */
@ -4239,6 +4286,12 @@ static void rbd_dev_release(struct device *dev)
module_put(THIS_MODULE);
}
static void __rbd_remove(struct rbd_device *rbd_dev)
{
rbd_remove_all_snaps(rbd_dev);
rbd_bus_del_dev(rbd_dev);
}
static ssize_t rbd_remove(struct bus_type *bus,
const char *buf,
size_t count)
@ -4274,8 +4327,26 @@ static ssize_t rbd_remove(struct bus_type *bus,
if (ret < 0)
goto done;
rbd_remove_all_snaps(rbd_dev);
rbd_bus_del_dev(rbd_dev);
while (rbd_dev->parent_spec) {
struct rbd_device *first = rbd_dev;
struct rbd_device *second = first->parent;
struct rbd_device *third;
/*
* Follow to the parent with no grandparent and
* remove it.
*/
while (second && (third = second->parent)) {
first = second;
second = third;
}
__rbd_remove(second);
rbd_spec_put(first->parent_spec);
first->parent_spec = NULL;
first->parent_overlap = 0;
first->parent = NULL;
}
__rbd_remove(rbd_dev);
done:
mutex_unlock(&ctl_mutex);