librbd: add create2 to create an image with the new format

This will fail if features are requested that the client or server
does not support. Currently there are no features defined, so
zero is the only valid value.

copy() preserves the format and features of the source image.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>

1 files changed, 56 insertions, 26 deletions

diff --git a/src/librbd.cc b/src/librbd.cc
index 8a5bf855d23..ae9c599e5b1 100644
--- a/src/librbd.cc
+++ b/src/librbd.cc
@@ -563,7 +563,8 @@ namespace librbd {
 
   int snap_set(ImageCtx *ictx, const char *snap_name);
   int list(IoCtx& io_ctx, std::vector<string>& names);
-  int create(IoCtx& io_ctx, const char *imgname, uint64_t size, int *order);
+  int create(IoCtx& io_ctx, const char *imgname, uint64_t size, int *order,
+	     bool old_format);
   int rename(IoCtx& io_ctx, const char *srcname, const char *dstname);
   int info(ImageCtx *ictx, image_info_t& info, size_t image_size);
   int remove(IoCtx& io_ctx, const char *imgname, ProgressContext& prog_ctx);
@@ -668,9 +669,6 @@ void init_rbd_header(struct rbd_obj_header_ondisk& ondisk,
 
   snprintf(ondisk.block_name, sizeof(ondisk.block_name), "rb.%x.%x", hi, lo);
 
-  if (!*order)
-    *order = RBD_DEFAULT_OBJ_ORDER;
-
   ondisk.image_size = size;
   ondisk.options.order = *order;
   ondisk.options.crypt_type = RBD_CRYPT_NONE;
@@ -977,18 +975,25 @@ int snap_remove(ImageCtx *ictx, const char *snap_name)
   return 0;
 }
 
-int create(IoCtx& io_ctx, const char *imgname, uint64_t size, int *order)
+int create(IoCtx& io_ctx, const char *imgname, uint64_t size,
+	   bool old_format, uint64_t features, int *order)
 {
   CephContext *cct = (CephContext *)io_ctx.cct();
-  ldout(cct, 20) << "create " << &io_ctx << " name = " << imgname << " size = " << size << dendl;
+  ldout(cct, 20) << "create " << &io_ctx << " name = " << imgname
+		 << " size = " << size << " old_format = " << old_format
+		 << " features = " << features << " order = " << *order
+		 << dendl;
 
-  string md_oid = imgname;
-  md_oid += RBD_SUFFIX;
 
-  // make sure it doesn't already exist
-  int r = io_ctx.stat(md_oid, NULL, NULL);
-  if (r == 0) {
-    lderr(cct) << "rbd image header " << md_oid << " already exists" << dendl;
+  if (features & ~RBD_FEATURES_ALL) {
+    lderr(cct) << "librbd does not support requested features." << dendl;
+    return -ENOSYS;
+  }
+
+  // make sure it doesn't already exist, in either format
+  int r = detect_format(io_ctx, imgname, NULL, NULL);
+  if (r != -ENOENT) {
+    lderr(cct) << "rbd image " << imgname << " already exists" << dendl;
     return -EEXIST;
   }
 
@@ -1008,23 +1013,33 @@ int create(IoCtx& io_ctx, const char *imgname, uint64_t size, int *order)
     return r;
   }
 
-  struct rbd_obj_header_ondisk header;
-  init_rbd_header(header, size, order, bid);
-
-  bufferlist bl;
-  bl.append((const char *)&header, sizeof(header));
-
   ldout(cct, 2) << "adding rbd image to directory..." << dendl;
   r = tmap_set(io_ctx, imgname);
   if (r < 0) {
-    lderr(cct) << "error adding img to directory: " << cpp_strerror(-r)<< dendl;
+    lderr(cct) << "error adding img to directory: " << cpp_strerror(r)<< dendl;
     return r;
   }
 
+  if (!*order)
+    *order = RBD_DEFAULT_OBJ_ORDER;
+
   ldout(cct, 2) << "creating rbd image..." << dendl;
-  r = io_ctx.write(md_oid, bl, bl.length(), 0);
+  string header_oid = md_oid(imgname, old_format);
+  if (old_format) {
+    struct rbd_obj_header_ondisk header;
+    init_rbd_header(header, size, order, bid);
+
+    bufferlist bl;
+    bl.append((const char *)&header, sizeof(header));
+    r = io_ctx.write(header_oid, bl, bl.length(), 0);
+  } else {
+    ostringstream oss;
+    oss << RBD_DATA_PREFIX << std::hex << bid;
+    r = cls_client::create_image(&io_ctx, header_oid, size, *order, features,
+				 oss.str());
+  }
   if (r < 0) {
-    lderr(cct) << "error writing header: " << cpp_strerror(-r) << dendl;
+    lderr(cct) << "error writing header: " << cpp_strerror(r) << dendl;
     return r;
   }
 
@@ -1541,8 +1556,9 @@ int copy(ImageCtx& ictx, IoCtx& dest_md_ctx, const char *destname,
   uint64_t src_size = ictx.get_image_size();
   int64_t r;
 
-  int order = ictx.header.options.order;
-  r = create(dest_md_ctx, destname, src_size, &order);
+  int order = ictx.order;
+  r = create(dest_md_ctx, destname, src_size, ictx.old_format,
+	     ictx.features, &order);
   if (r < 0) {
     lderr(cct) << "header creation failed" << dendl;
     return r;
@@ -2251,8 +2267,13 @@ int RBD::open(IoCtx& io_ctx, Image& image, const char *name, const char *snapnam
 
 int RBD::create(IoCtx& io_ctx, const char *name, uint64_t size, int *order)
 {
-  int r = librbd::create(io_ctx, name, size, order);
-  return r;
+  return librbd::create(io_ctx, name, size, true, 0, order);
+}
+
+int RBD::create2(IoCtx& io_ctx, const char *name, uint64_t size,
+		 uint64_t features, int *order)
+{
+  return librbd::create(io_ctx, name, size, false, features, order);
 }
 
 int RBD::remove(IoCtx& io_ctx, const char *name)
@@ -2506,7 +2527,16 @@ extern "C" int rbd_create(rados_ioctx_t p, const char *name, uint64_t size, int
 {
   librados::IoCtx io_ctx;
   librados::IoCtx::from_rados_ioctx_t(p, io_ctx);
-  return librbd::create(io_ctx, name, size, order);
+  return librbd::create(io_ctx, name, size, true, 0, order);
+}
+
+extern "C" int rbd_create2(rados_ioctx_t p, const char *name,
+			   uint64_t size, uint64_t features,
+			   int *order)
+{
+  librados::IoCtx io_ctx;
+  librados::IoCtx::from_rados_ioctx_t(p, io_ctx);
+  return librbd::create(io_ctx, name, size, false, features, order);
 }
 
 extern "C" int rbd_remove(rados_ioctx_t p, const char *name)