Reviewed-by: Josh Durgin <[email protected]>
On 09/07/2012 12:25 PM, Alex Elder wrote:
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 <[email protected]> --- drivers/block/rbd.c | 36 ++++++++++++++++++++++++++++++------ 1 file changed, 30 insertions(+), 6 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index c62d3f4..e6b8fa6 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2097,6 +2097,25 @@ 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 @@ -2113,7 +2132,6 @@ 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; @@ -2122,6 +2140,9 @@ 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; @@ -2148,16 +2169,20 @@ 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); @@ -2178,9 +2203,9 @@ 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 */ @@ -2190,7 +2215,6 @@ 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__);
-- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
