1 files changed, 97 insertions, 14 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index bec5a50c9890..73ed5f3a862d 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4207,11 +4207,13 @@ static ssize_t rbd_parent_show(struct device *dev,
 
                 count += sprintf(&buf[count], "%s"
                             "pool_id %llu\npool_name %s\n"
+                            "pool_ns %s\n"
                             "image_id %s\nimage_name %s\n"
                             "snap_id %llu\nsnap_name %s\n"
                             "overlap %llu\n",
                             !count ? "" : "\n", /* first? */
                             spec->pool_id, spec->pool_name,
+                            spec->pool_ns ?: "",
                             spec->image_id, spec->image_name ?: "(unknown)",
                             spec->snap_id, spec->snap_name,
                             rbd_dev->parent_overlap);
@@ -4586,15 +4588,92 @@ static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
 
 struct parent_image_info {
         u64             pool_id;
+        const char      *pool_ns;
         const char      *image_id;
         u64             snap_id;
 
+        bool            has_overlap;
         u64             overlap;
 };
 
 /*
  * The caller is responsible for @pii.
  */
+static int decode_parent_image_spec(void **p, void *end,
+                                    struct parent_image_info *pii)
+{
+        u8 struct_v;
+        u32 struct_len;
+        int ret;
+
+        ret = ceph_start_decoding(p, end, 1, "ParentImageSpec",
+                                  &struct_v, &struct_len);
+        if (ret)
+                return ret;
+
+        ceph_decode_64_safe(p, end, pii->pool_id, e_inval);
+        pii->pool_ns = ceph_extract_encoded_string(p, end, NULL, GFP_KERNEL);
+        if (IS_ERR(pii->pool_ns)) {
+                ret = PTR_ERR(pii->pool_ns);
+                pii->pool_ns = NULL;
+                return ret;
+        }
+        pii->image_id = ceph_extract_encoded_string(p, end, NULL, GFP_KERNEL);
+        if (IS_ERR(pii->image_id)) {
+                ret = PTR_ERR(pii->image_id);
+                pii->image_id = NULL;
+                return ret;
+        }
+        ceph_decode_64_safe(p, end, pii->snap_id, e_inval);
+        return 0;
+
+e_inval:
+        return -EINVAL;
+}
+
+static int __get_parent_info(struct rbd_device *rbd_dev,
+                             struct page *req_page,
+                             struct page *reply_page,
+                             struct parent_image_info *pii)
+{
+        struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+        size_t reply_len = PAGE_SIZE;
+        void *p, *end;
+        int ret;
+
+        ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
+                             "rbd", "parent_get", CEPH_OSD_FLAG_READ,
+                             req_page, sizeof(u64), reply_page, &reply_len);
+        if (ret)
+                return ret == -EOPNOTSUPP ? 1 : ret;
+
+        p = page_address(reply_page);
+        end = p + reply_len;
+        ret = decode_parent_image_spec(&p, end, pii);
+        if (ret)
+                return ret;
+
+        ret = ceph_osdc_call(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
+                             "rbd", "parent_overlap_get", CEPH_OSD_FLAG_READ,
+                             req_page, sizeof(u64), reply_page, &reply_len);
+        if (ret)
+                return ret;
+
+        p = page_address(reply_page);
+        end = p + reply_len;
+        ceph_decode_8_safe(&p, end, pii->has_overlap, e_inval);
+        if (pii->has_overlap)
+                ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
+
+        return 0;
+
+e_inval:
+        return -EINVAL;
+}
+
+/*
+ * The caller is responsible for @pii.
+ */
 static int __get_parent_info_legacy(struct rbd_device *rbd_dev,
                                     struct page *req_page,
                                     struct page *reply_page,
@@ -4621,6 +4700,7 @@ static int __get_parent_info_legacy(struct rbd_device *rbd_dev,
                 return ret;
         }
         ceph_decode_64_safe(&p, end, pii->snap_id, e_inval);
+        pii->has_overlap = true;
         ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
 
         return 0;
@@ -4648,7 +4728,10 @@ static int get_parent_info(struct rbd_device *rbd_dev,
 
         p = page_address(req_page);
         ceph_encode_64(&p, rbd_dev->spec->snap_id);
-        ret = __get_parent_info_legacy(rbd_dev, req_page, reply_page, pii);
+        ret = __get_parent_info(rbd_dev, req_page, reply_page, pii);
+        if (ret > 0)
+                ret = __get_parent_info_legacy(rbd_dev, req_page, reply_page,
+                                               pii);
 
         __free_page(req_page);
         __free_page(reply_page);
@@ -4669,10 +4752,11 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
         if (ret)
                 goto out_err;
 
-        dout("%s pool_id %llu image_id %s snap_id %llu overlap %llu\n",
-             __func__, pii.pool_id, pii.image_id, pii.snap_id, pii.overlap);
+        dout("%s pool_id %llu pool_ns %s image_id %s snap_id %llu has_overlap %d overlap %llu\n",
+             __func__, pii.pool_id, pii.pool_ns, pii.image_id, pii.snap_id,
+             pii.has_overlap, pii.overlap);
 
-        if (pii.pool_id == CEPH_NOPOOL) {
+        if (pii.pool_id == CEPH_NOPOOL || !pii.has_overlap) {
                 /*
                  * Either the parent never existed, or we have
                  * record of it but the image got flattened so it no
@@ -4681,6 +4765,10 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
                  * overlap to 0.  The effect of this is that all new
                  * requests will be treated as if the image had no
                  * parent.
+                 *
+                 * If !pii.has_overlap, the parent image spec is not
+                 * applicable.  It's there to avoid duplication in each
+                 * snapshot record.
                  */
                 if (rbd_dev->parent_overlap) {
                         rbd_dev->parent_overlap = 0;
@@ -4708,20 +4796,14 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
          */
         if (!rbd_dev->parent_spec) {
                 parent_spec->pool_id = pii.pool_id;
+                if (pii.pool_ns && *pii.pool_ns) {
+                        parent_spec->pool_ns = pii.pool_ns;
+                        pii.pool_ns = NULL;
+                }
                 parent_spec->image_id = pii.image_id;
                 pii.image_id = NULL;
                 parent_spec->snap_id = pii.snap_id;
 
-                /* TODO: support cloning across namespaces */
-                if (rbd_dev->spec->pool_ns) {
-                        parent_spec->pool_ns = kstrdup(rbd_dev->spec->pool_ns,
-                                                       GFP_KERNEL);
-                        if (!parent_spec->pool_ns) {
-                                ret = -ENOMEM;
-                                goto out_err;
-                        }
-                }
-
                 rbd_dev->parent_spec = parent_spec;
                 parent_spec = NULL;     /* rbd_dev now owns this */
         }
@@ -4746,6 +4828,7 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
 out:
         ret = 0;
 out_err:
+        kfree(pii.pool_ns);
         kfree(pii.image_id);
         rbd_spec_put(parent_spec);
         return ret;