From: Samuel Just <sjust@redhat.com>
Date: Wed, 9 Oct 2019 22:06:55 +0000 (-0700)
Subject: crimson/osd/pg_backend: factor out load_object_state/snapset
X-Git-Tag: v15.1.0~687^2~2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=fd803498dffc5e2defdce17659df5a59aed80f8d;p=ceph.git

crimson/osd/pg_backend: factor out load_object_state/snapset

Signed-off-by: Samuel Just <sjust@redhat.com>
---

diff --git a/src/crimson/os/cyanstore/cyan_store.cc b/src/crimson/os/cyanstore/cyan_store.cc
index 6bc620430df5..0cd89953743d 100644
--- a/src/crimson/os/cyanstore/cyan_store.cc
+++ b/src/crimson/os/cyanstore/cyan_store.cc
@@ -217,17 +217,18 @@ CyanStore::get_attr_errorator::future<ceph::bufferptr> CyanStore::get_attr(
   }
 }
 
-seastar::future<CyanStore::attrs_t> CyanStore::get_attrs(CollectionRef ch,
-                                                         const ghobject_t& oid)
+CyanStore::get_attrs_ertr::future<CyanStore::attrs_t> CyanStore::get_attrs(
+  CollectionRef ch,
+  const ghobject_t& oid)
 {
   auto c = static_cast<Collection*>(ch.get());
   logger().debug("{} {} {}",
-                __func__, c->get_cid(), oid);
+		 __func__, c->get_cid(), oid);
   auto o = c->get_object(oid);
   if (!o) {
-    throw std::runtime_error(fmt::format("object does not exist: {}", oid));
+    return crimson::ct_error::enoent::make();
   }
-  return seastar::make_ready_future<attrs_t>(o->xattr);
+  return get_attrs_ertr::make_ready_future<attrs_t>(o->xattr);
 }
 
 seastar::future<CyanStore::omap_values_t>
diff --git a/src/crimson/os/cyanstore/cyan_store.h b/src/crimson/os/cyanstore/cyan_store.h
index 7fab6d643eb0..977cf2ff9293 100644
--- a/src/crimson/os/cyanstore/cyan_store.h
+++ b/src/crimson/os/cyanstore/cyan_store.h
@@ -54,8 +54,9 @@ public:
     CollectionRef c,
     const ghobject_t& oid,
     std::string_view name) const final;
-  seastar::future<attrs_t> get_attrs(CollectionRef c,
-                                     const ghobject_t& oid) final;
+  get_attrs_ertr::future<attrs_t> get_attrs(
+    CollectionRef c,
+    const ghobject_t& oid);
 
   seastar::future<omap_values_t> omap_get_values(
     CollectionRef c,
diff --git a/src/crimson/os/futurized_store.h b/src/crimson/os/futurized_store.h
index b7ac7d7dff7a..388b965148ee 100644
--- a/src/crimson/os/futurized_store.h
+++ b/src/crimson/os/futurized_store.h
@@ -58,9 +58,13 @@ public:
     const ghobject_t& oid,
     std::string_view name) const = 0;
 
+  using get_attrs_ertr = crimson::errorator<
+    crimson::ct_error::enoent>;
   using attrs_t = std::map<std::string, ceph::bufferptr, std::less<>>;
-  virtual seastar::future<attrs_t> get_attrs(CollectionRef c,
-                                             const ghobject_t& oid) = 0;
+  virtual get_attrs_ertr::future<attrs_t> get_attrs(
+    CollectionRef c,
+    const ghobject_t& oid) = 0;
+
   using omap_values_t = std::map<std::string, bufferlist, std::less<>>;
   using omap_keys_t = std::set<std::string>;
   virtual seastar::future<omap_values_t> omap_get_values(
diff --git a/src/crimson/osd/pg_backend.cc b/src/crimson/osd/pg_backend.cc
index ae81708ad2fb..a0a59b466dd8 100644
--- a/src/crimson/osd/pg_backend.cc
+++ b/src/crimson/osd/pg_backend.cc
@@ -17,6 +17,7 @@
 #include "crimson/os/cyanstore/cyan_object.h"
 #include "crimson/os/futurized_collection.h"
 #include "crimson/os/futurized_store.h"
+#include "crimson/osd/osd_operation.h"
 #include "replicated_backend.h"
 #include "ec_backend.h"
 #include "exceptions.h"
@@ -107,29 +108,57 @@ PGBackend::get_object_state(const hobject_t& oid)
   }
 }
 
+PGBackend::load_metadata_ertr::future<PGBackend::loaded_object_md_t>
+PGBackend::load_metadata(const hobject_t& oid)
+{
+  return store->get_attrs(
+    coll,
+    ghobject_t{oid, ghobject_t::NO_GEN, shard}).safe_then(
+      [oid, this](auto &&attrs) -> load_metadata_ertr::future<loaded_object_md_t>{
+	loaded_object_md_t ret;
+	if (auto oiiter = attrs.find(OI_ATTR); oiiter != attrs.end()) {
+	  bufferlist bl;
+	  bl.push_back(oiiter->second);
+	  ret.os = ObjectState(
+	    object_info_t(bl),
+	    true);
+	} else {
+	  return crimson::ct_error::object_corrupted::make();
+	}
+	
+	if (oid.is_head()) {
+	  if (auto ssiter = attrs.find(SS_ATTR); ssiter != attrs.end()) {
+	    bufferlist bl;
+	    bl.push_back(ssiter->second);
+	    ret.ss = SnapSet(bl);
+	  } else {
+	    return crimson::ct_error::object_corrupted::make();
+	  }
+	}
+
+	return load_metadata_ertr::make_ready_future<loaded_object_md_t>(
+	  std::move(ret));
+      }, crimson::ct_error::enoent::handle([oid, this] {
+	return load_metadata_ertr::make_ready_future<loaded_object_md_t>(
+	  loaded_object_md_t{
+	    ObjectState(),
+	    std::nullopt
+	  });
+      }));
+}
+
 PGBackend::get_os_errorator::future<PGBackend::cached_os_t>
 PGBackend::_load_os(const hobject_t& oid)
 {
   if (auto found = os_cache.find(oid); found) {
     return get_os_errorator::make_ready_future<cached_os_t>(std::move(found));
   }
-  return store->get_attr(coll,
-                         ghobject_t{oid, ghobject_t::NO_GEN, shard},
-                         OI_ATTR)
-  .safe_then(
-    [oid, this] (ceph::bufferptr&& bp) {
-      // decode existing OI_ATTR's value
-      ceph::bufferlist bl;
-      bl.push_back(std::move(bp));
-      return get_os_errorator::make_ready_future<cached_os_t>(
-        os_cache.insert(oid,
-          std::make_unique<ObjectState>(object_info_t{bl}, true /* exists */)));
-    }, crimson::errorator<crimson::ct_error::enoent,
-                          crimson::ct_error::enodata>::all_same_way([oid, this] {
-      return get_os_errorator::make_ready_future<cached_os_t>(
-        os_cache.insert(oid,
-          std::make_unique<ObjectState>(object_info_t{oid}, false)));
-    }));
+  return load_metadata(oid).safe_then([oid, this](auto &&md) {
+    return get_os_errorator::make_ready_future<cached_os_t>(
+      os_cache.insert(
+	oid,
+	std::make_unique<ObjectState>(std::move(md.os))));
+  });
 }
 
 PGBackend::get_os_errorator::future<PGBackend::cached_ss_t>
@@ -138,25 +167,15 @@ PGBackend::_load_ss(const hobject_t& oid)
   if (auto found = ss_cache.find(oid); found) {
     return get_os_errorator::make_ready_future<cached_ss_t>(std::move(found));
   }
-  return store->get_attr(coll,
-                         ghobject_t{oid, ghobject_t::NO_GEN, shard},
-                         SS_ATTR)
-  .safe_then(
-    [oid, this] (ceph::bufferptr&& bp) {
-      // decode existing SS_ATTR's value
-      ceph::bufferlist bl;
-      bl.push_back(std::move(bp));
+  return load_metadata(oid).safe_then([oid, this](auto &&md) {
+    if (!md.ss) {
       return get_os_errorator::make_ready_future<cached_ss_t>(
-        ss_cache.insert(oid, std::make_unique<SnapSet>(bl)));
-    }, crimson::errorator<crimson::ct_error::enoent,
-                          crimson::ct_error::enodata>::all_same_way([oid, this] {
-      // NOTE: the errors could have been handled by writing just:
-      //   `get_attr_errorator::all_same_way(...)`.
-      // however, this way is more explicit and resilient to unexpected
-      // changes in the alias definition.
+	std::make_unique<SnapSet>());
+    } else {
       return get_os_errorator::make_ready_future<cached_ss_t>(
-        ss_cache.insert(oid, std::make_unique<SnapSet>()));
-    }));
+	ss_cache.insert(oid, std::make_unique<SnapSet>(std::move(*(md.ss)))));
+    }
+  });
 }
 
 seastar::future<crimson::osd::acked_peers_t>
diff --git a/src/crimson/osd/pg_backend.h b/src/crimson/osd/pg_backend.h
index d355ab02598e..b2ba4fd2c7b4 100644
--- a/src/crimson/osd/pg_backend.h
+++ b/src/crimson/osd/pg_backend.h
@@ -123,17 +123,30 @@ protected:
   CollectionRef coll;
   crimson::os::FuturizedStore* store;
 
+public:
+  using load_metadata_ertr = crimson::errorator<
+    crimson::ct_error::object_corrupted>;
+  struct loaded_object_md_t {
+    ObjectState os;
+    std::optional<SnapSet> ss;
+  };
+  load_metadata_ertr::future<loaded_object_md_t> load_metadata(
+    const hobject_t &oid);
+
 private:
   using cached_ss_t = boost::local_shared_ptr<SnapSet>;
   SharedLRU<hobject_t, SnapSet> ss_cache;
   get_os_errorator::future<cached_ss_t> _load_ss(const hobject_t& oid);
+
   SharedLRU<hobject_t, ObjectState> os_cache;
   get_os_errorator::future<cached_os_t> _load_os(const hobject_t& oid);
+
   virtual ll_read_errorator::future<ceph::bufferlist> _read(
     const hobject_t& hoid,
     size_t offset,
     size_t length,
     uint32_t flags) = 0;
+
   bool maybe_create_new_object(ObjectState& os, ceph::os::Transaction& txn);
   virtual seastar::future<crimson::osd::acked_peers_t>
   _submit_transaction(std::set<pg_shard_t>&& pg_shards,