@@ -66,6 +66,8 @@
#define RBD_SNAP_HEAD_NAME "-"
+#define BAD_SNAP_INDEX U32_MAX /* invalid index into snap array */
+
/* This allows a single page to hold an image name sent by OSD */
#define RBD_IMAGE_NAME_LEN_MAX (PAGE_SIZE - sizeof (__le32) - 1)
#define RBD_IMAGE_ID_LEN_MAX 64
@@ -809,6 +811,33 @@ out_err:
return -ENOMEM;
}
+static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
u32 which)
+{
+ const char *snap_name;
+
+ rbd_assert(which < rbd_dev->header.snapc->num_snaps);
+
+ /* 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 kstrdup(snap_name, GFP_KERNEL);
+}
+
+static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
+{
+ struct ceph_snap_context *snapc = rbd_dev->header.snapc;
+ u32 which;
+
+ for (which = 0; which < snapc->num_snaps; which++)
+ if (snapc->snaps[which] == snap_id)
+ return which;
+
+ return BAD_SNAP_INDEX;
+}
+
static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
{
Rather than scanning the list of snapshot structures for it, scan the snapshot context buffer containing snapshot names in order to determine for a format 1 image the name associated with a given snapshot id. Pull out the part of rbd_dev_v1_snap_info() that does this scan into a new function, _rbd_dev_v1_snap_name(). Have that function return a dynamically-allocated copy of the name, and don't duplicate it in rbd_dev_v1_snap_info(). Signed-off-by: Alex Elder <elder@inktank.com> --- drivers/block/rbd.c | 40 ++++++++++++++++++++++++++++++---------- 1 file changed, 30 insertions(+), 10 deletions(-) struct rbd_snap *snap; @@ -3421,17 +3450,8 @@ static const char *rbd_dev_v1_snap_info(struct rbd_device *rbd_dev, u32 which, u64 *snap_size, u64 *snap_features) { const char *snap_name; - int i; - - rbd_assert(which < rbd_dev->header.snapc->num_snaps); - - /* Skip over names until we find the one we are looking for */ - snap_name = rbd_dev->header.snap_names; - for (i = 0; i < which; i++) - snap_name += strlen(snap_name) + 1; - - snap_name = kstrdup(snap_name, GFP_KERNEL); + snap_name = _rbd_dev_v1_snap_name(rbd_dev, which); if (!snap_name) return ERR_PTR(-ENOMEM);