rbd: encapsulate code that gets snapshot info
Create a function that encapsulates looking up the name, size and features related to a given snapshot, which is indicated by its index in an rbd device's snapshot context array of snapshot ids. This interface will be used to hide differences between the format 1 and format 2 images. At the moment this (looking up the name anyway) is slightly less efficient than what's done currently, but we may be able to optimize this a bit later on by cacheing the last lookup if it proves to be a problem. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
parent
34b131849f
commit
cd892126c6
|
@ -2102,6 +2102,25 @@ err:
|
|||
return ERR_PTR(ret);
|
||||
}
|
||||
|
||||
static char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev, u32 which,
|
||||
u64 *snap_size, u64 *snap_features)
|
||||
{
|
||||
char *snap_name;
|
||||
|
||||
rbd_assert(which < rbd_dev->header.snapc->num_snaps);
|
||||
|
||||
*snap_size = rbd_dev->header.snap_sizes[which];
|
||||
*snap_features = 0; /* No features for v1 */
|
||||
|
||||
/* Skip over names until we find the one we are looking for */
|
||||
|
||||
snap_name = rbd_dev->header.snap_names;
|
||||
while (which--)
|
||||
snap_name += strlen(snap_name) + 1;
|
||||
|
||||
return snap_name;
|
||||
}
|
||||
|
||||
/*
|
||||
* Scan the rbd device's current snapshot list and compare it to the
|
||||
* newly-received snapshot context. Remove any existing snapshots
|
||||
|
@ -2118,7 +2137,6 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
|
|||
{
|
||||
struct ceph_snap_context *snapc = rbd_dev->header.snapc;
|
||||
const u32 snap_count = snapc->num_snaps;
|
||||
char *snap_name = rbd_dev->header.snap_names;
|
||||
struct list_head *head = &rbd_dev->snaps;
|
||||
struct list_head *links = head->next;
|
||||
u32 index = 0;
|
||||
|
@ -2127,6 +2145,9 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
|
|||
while (index < snap_count || links != head) {
|
||||
u64 snap_id;
|
||||
struct rbd_snap *snap;
|
||||
char *snap_name;
|
||||
u64 snap_size = 0;
|
||||
u64 snap_features = 0;
|
||||
|
||||
snap_id = index < snap_count ? snapc->snaps[index]
|
||||
: CEPH_NOSNAP;
|
||||
|
@ -2153,16 +2174,20 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
|
|||
continue;
|
||||
}
|
||||
|
||||
snap_name = rbd_dev_v1_snap_info(rbd_dev, index,
|
||||
&snap_size, &snap_features);
|
||||
if (IS_ERR(snap_name))
|
||||
return PTR_ERR(snap_name);
|
||||
|
||||
dout("entry %u: snap_id = %llu\n", (unsigned int) snap_count,
|
||||
(unsigned long long) snap_id);
|
||||
if (!snap || (snap_id != CEPH_NOSNAP && snap->id < snap_id)) {
|
||||
struct rbd_image_header *header = &rbd_dev->header;
|
||||
struct rbd_snap *new_snap;
|
||||
|
||||
/* We haven't seen this snapshot before */
|
||||
|
||||
new_snap = __rbd_add_snap_dev(rbd_dev, snap_name,
|
||||
snap_id, header->snap_sizes[index], 0);
|
||||
snap_id, snap_size, snap_features);
|
||||
if (IS_ERR(new_snap)) {
|
||||
int err = PTR_ERR(new_snap);
|
||||
|
||||
|
@ -2183,9 +2208,9 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
|
|||
|
||||
dout(" already present\n");
|
||||
|
||||
rbd_assert(snap->size ==
|
||||
rbd_dev->header.snap_sizes[index]);
|
||||
rbd_assert(snap->size == snap_size);
|
||||
rbd_assert(!strcmp(snap->name, snap_name));
|
||||
rbd_assert(snap->features == snap_features);
|
||||
|
||||
/* Done with this list entry; advance */
|
||||
|
||||
|
@ -2195,7 +2220,6 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
|
|||
/* Advance to the next entry in the snapshot context */
|
||||
|
||||
index++;
|
||||
snap_name += strlen(snap_name) + 1;
|
||||
}
|
||||
dout("%s: done\n", __func__);
|
||||
|
||||
|
|
Loading…
Reference in a new issue