From: Matthew N. Heler <matthew.heler@hotmail.com>
Date: Fri, 5 Dec 2025 16:52:55 +0000 (-0600)
Subject: rgw/cloud-transition: check bucket existence before create
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=08060dea5990491174d9b9fe2fd21828256459be;p=ceph-ci.git

rgw/cloud-transition: check bucket existence before create

Add HEAD request to check if target bucket exists before attempting
to create it. This avoids unnecessary PUT requests when the bucket
already exists on the remote endpoint.

Signed-off-by: Matthew N. Heler <matthew.heler@hotmail.com>
---

diff --git a/src/rgw/driver/rados/rgw_lc_tier.cc b/src/rgw/driver/rados/rgw_lc_tier.cc
index 046072e5651..7e68a598fad 100644
--- a/src/rgw/driver/rados/rgw_lc_tier.cc
+++ b/src/rgw/driver/rados/rgw_lc_tier.cc
@@ -1448,6 +1448,24 @@ static int cloud_tier_check_object(RGWLCCloudTierCtx& tier_ctx, bool& already_ti
   return ret;
 }
 
+static int cloud_tier_bucket_exists(RGWLCCloudTierCtx& tier_ctx)
+{
+  bufferlist out_bl;
+  string resource = tier_ctx.target_bucket_name;
+
+  int ret = tier_ctx.conn.send_resource(tier_ctx.dpp, "HEAD", resource,
+                                        nullptr, nullptr, out_bl, nullptr,
+                                        nullptr, null_yield);
+  if (ret == -ERR_NO_SUCH_BUCKET || ret == -ENOENT) {
+    return -ENOENT;
+  }
+  if (ret < 0) {
+    ldpp_dout(tier_ctx.dpp, 0) << "HEAD target bucket " << resource
+                               << " returned ret=" << ret << dendl;
+  }
+  return ret;
+}
+
 static int cloud_tier_create_bucket(RGWLCCloudTierCtx& tier_ctx) {
   bufferlist out_bl;
   int ret = 0;
@@ -1527,18 +1545,21 @@ static int cloud_tier_create_bucket(RGWLCCloudTierCtx& tier_ctx) {
 int rgw_cloud_tier_transfer_object(RGWLCCloudTierCtx& tier_ctx, std::set<std::string>& cloud_targets) {
   int ret = 0;
 
-  // check if target_path is already created
-  std::set<std::string>::iterator it;
-
-  it = cloud_targets.find(tier_ctx.target_bucket_name);
+  // check if target bucket is in local cache
+  auto it = cloud_targets.find(tier_ctx.target_bucket_name);
   tier_ctx.target_bucket_created = (it != cloud_targets.end());
 
-  /* If run first time attempt to create the target bucket */
   if (!tier_ctx.target_bucket_created) {
-    ret = cloud_tier_create_bucket(tier_ctx);
-
-    if (ret < 0) {
-      ldpp_dout(tier_ctx.dpp, 0) << "ERROR: failed to create target bucket on the cloud endpoint ret=" << ret << dendl;
+    // not in cache; check if bucket exists on remote
+    ret = cloud_tier_bucket_exists(tier_ctx);
+    if (ret == -ENOENT) {
+      ret = cloud_tier_create_bucket(tier_ctx);
+      if (ret < 0) {
+        ldpp_dout(tier_ctx.dpp, 0) << "ERROR: failed to create target bucket on the cloud endpoint ret=" << ret << dendl;
+        return ret;
+      }
+    } else if (ret < 0) {
+      ldpp_dout(tier_ctx.dpp, 0) << "ERROR: failed to check target bucket on the cloud endpoint ret=" << ret << dendl;
       return ret;
     }
     tier_ctx.target_bucket_created = true;