From d7b0e77b56ae10d985652b7f1955e2c98f196b9a Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Thu, 16 Sep 2021 12:09:54 -0500
Subject: [PATCH] os/bluestore: give conventional region of SMR to bluefs

Let bluefs use the conventional region of an SMR HDD.  It won't be able to
use the sequential region if it runs out of space, but it does mean that
bluefs can function on an SMR drive without a dedicated db/wal device.

Signed-off-by: Sage Weil <sage@newdream.net>
---
 src/os/bluestore/BlueStore.cc                 | 52 ++++++++++++++++---
 .../objectstore/run_smr_bluestore_test.sh     |  2 -
 2 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index e13af070afa..a3859480fb4 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -5595,8 +5595,27 @@ int BlueStore::_create_alloc()
     return -EINVAL;
   }
 
-  // BlueFS will share the same allocator
-  shared_alloc.set(alloc);
+#ifdef HAVE_LIBZBD
+  if (freelist_type == "zoned") {
+    Allocator *a = Allocator::create(
+      cct, cct->_conf->bluestore_allocator,
+      bdev->get_conventional_region_size(),
+      alloc_size,
+      0, 0,
+      "zoned_block");
+    if (!a) {
+      lderr(cct) << __func__ << " failed to create " << cct->_conf->bluestore_allocator
+		 << " allocator" << dendl;
+      delete alloc;
+      return -EINVAL;
+    }
+    shared_alloc.set(a);
+  } else
+#endif
+  {
+    // BlueFS will share the same allocator
+    shared_alloc.set(alloc);
+  }
 
   return 0;
 }
@@ -5644,6 +5663,15 @@ int BlueStore::_init_alloc(std::map<uint64_t, uint64_t> *zone_adjustments)
       }
     }
 
+    // start with conventional zone "free" (bluefs may adjust this when it starts up)
+    auto reserved = _get_ondisk_reserved();
+    // for now we require a conventional zone
+    ceph_assert(bdev->get_conventional_region_size());
+    ceph_assert(shared_alloc.a != alloc);  // zoned allocator doesn't use conventional region
+    shared_alloc.a->init_add_free(reserved,
+				  bdev->get_conventional_region_size() - reserved);
+
+    // init sequential zone based on the device's write pointers
     a->init_from_zone_pointers(zones);
     dout(1) << __func__
 	    << " loaded zone pointers: "
@@ -5738,11 +5766,16 @@ void BlueStore::_close_alloc()
   ceph_assert(bdev);
   bdev->discard_drain();
 
-  ceph_assert(shared_alloc.a);
   ceph_assert(alloc);
-  ceph_assert(alloc == shared_alloc.a);
-  shared_alloc.a->shutdown();
-  delete shared_alloc.a;
+  alloc->shutdown();
+  delete alloc;
+
+  ceph_assert(shared_alloc.a);
+  if (alloc != shared_alloc.a) {
+    shared_alloc.a->shutdown();
+    delete shared_alloc.a;
+  }
+
   shared_alloc.reset();
   alloc = nullptr;
 }
@@ -6852,6 +6885,13 @@ int BlueStore::mkfs()
   reserved = _get_ondisk_reserved();
   alloc->init_add_free(reserved,
     p2align(bdev->get_size(), min_alloc_size) - reserved);
+#ifdef HAVE_LIBZBD
+  if (bdev->is_smr() && alloc != shared_alloc.a) {
+    shared_alloc.a->init_add_free(reserved,
+				  p2align(bdev->get_conventional_region_size(),
+					  min_alloc_size) - reserved);
+  }
+#endif
 
   r = _open_db(true);
   if (r < 0)
diff --git a/src/test/objectstore/run_smr_bluestore_test.sh b/src/test/objectstore/run_smr_bluestore_test.sh
index 22017b0c5cb..5fa8544e0a1 100644
--- a/src/test/objectstore/run_smr_bluestore_test.sh
+++ b/src/test/objectstore/run_smr_bluestore_test.sh
@@ -22,6 +22,4 @@ DEV=`lsscsi | grep zbc | awk '{print $7}'`
 sudo ceph_test_objectstore \
     --bluestore-block-path $DEV \
     --gtest_filter=*/2 \
-    --bluestore-block-db-create \
-    --bluestore-block-db-size 1048576000 \
     $*
-- 
2.39.5