librbd/cache/pwl: Fix dead lock issue when pwl initialization failed

when pwl initialization failed, 'AbstractWriteLog' will release itself
in callback, it hold guard lock and want to get lock to delete data,
which causes dead lock. This PR works by release image_cache outside
the callback function.

Signed-off-by: Yin Congmin <congmin.yin@intel.com>
(cherry picked from commit 937af36e204791554708632245b4bca1d52f49a6)

diff --git a/src/librbd/cache/pwl/AbstractWriteLog.cc b/src/librbd/cache/pwl/AbstractWriteLog.cc
index 388f1dcee649472f8011c4a29b9147332948b8b3..7b8aa43025047bed2b9b08f3e3903f10913e40f3 100644 (file)
--- a/src/librbd/cache/pwl/AbstractWriteLog.cc
+++ b/src/librbd/cache/pwl/AbstractWriteLog.cc
@@ -529,7 +529,10 @@ void AbstractWriteLog<I>::pwl_init(Context *on_finish, DeferredContexts &later)
     return;
   }
 
-  initialize_pool(on_finish, later);
+  bool succeeded = initialize_pool(on_finish, later);
+  if (!succeeded) {
+    return ;
+  }
 
   ldout(cct,1) << "pool " << m_log_pool_name << " has " << m_total_log_entries
                << " log entries, " << m_free_log_entries << " of which are free."

diff --git a/src/librbd/cache/pwl/AbstractWriteLog.h b/src/librbd/cache/pwl/AbstractWriteLog.h
index fb6a07992b9e41a4242a2683fd5f0a1c58d33751..c982d2631fe3f407e6cd009c10f9f71811e039a0 100644 (file)
--- a/src/librbd/cache/pwl/AbstractWriteLog.h
+++ b/src/librbd/cache/pwl/AbstractWriteLog.h
@@ -364,7 +364,7 @@ protected:
   virtual void append_scheduled_ops(void) = 0;
   virtual void schedule_append_ops(pwl::GenericLogOperations &ops, C_BlockIORequestT *req) = 0;
   virtual void remove_pool_file() = 0;
-  virtual void initialize_pool(Context *on_finish,
+  virtual bool initialize_pool(Context *on_finish,
                                pwl::DeferredContexts &later) = 0;
   virtual void collect_read_extents(
       uint64_t read_buffer_offset, LogMapEntry<GenericWriteLogEntry> map_entry,

diff --git a/src/librbd/cache/pwl/InitRequest.cc b/src/librbd/cache/pwl/InitRequest.cc
index ea00d4fbc7664410a19b0f276c90a24d9030cd52..a6d0fb44a1de1b138da5a9a80ac11172ff72a3da 100644 (file)
--- a/src/librbd/cache/pwl/InitRequest.cc
+++ b/src/librbd/cache/pwl/InitRequest.cc
@@ -122,8 +122,8 @@ void InitRequest<I>::init_image_cache() {
   ldout(cct, 10) << dendl;
 
   using klass = InitRequest<I>;
-  Context *ctx = create_context_callback<
-    klass, &klass::handle_init_image_cache>(this);
+  Context *ctx = create_async_context_callback(m_image_ctx,
+    create_context_callback<klass, &klass::handle_init_image_cache>(this));
   m_image_cache->init(ctx);
 }
 

diff --git a/src/librbd/cache/pwl/rwl/WriteLog.cc b/src/librbd/cache/pwl/rwl/WriteLog.cc
index 38d0e9131f8c399e758e6a265b8ed380f95e2718..80a83510c3163dd077705f08cf32b189946343a9 100644 (file)
--- a/src/librbd/cache/pwl/rwl/WriteLog.cc
+++ b/src/librbd/cache/pwl/rwl/WriteLog.cc
@@ -258,7 +258,7 @@ void WriteLog<I>::remove_pool_file() {
 }
 
 template <typename I>
-void WriteLog<I>::initialize_pool(Context *on_finish, pwl::DeferredContexts &later) {
+bool WriteLog<I>::initialize_pool(Context *on_finish, pwl::DeferredContexts &later) {
   CephContext *cct = m_image_ctx.cct;
   TOID(struct WriteLogPoolRoot) pool_root;
   ceph_assert(ceph_mutex_is_locked_by_me(m_lock));
@@ -275,7 +275,7 @@ void WriteLog<I>::initialize_pool(Context *on_finish, pwl::DeferredContexts &lat
       m_cache_state->empty = true;
       /* TODO: filter/replace errnos that are meaningless to the caller */
       on_finish->complete(-errno);
-      return;
+      return false;
     }
     m_cache_state->present = true;
     m_cache_state->clean = true;
@@ -292,7 +292,7 @@ void WriteLog<I>::initialize_pool(Context *on_finish, pwl::DeferredContexts &lat
     if (num_small_writes <= 2) {
       lderr(cct) << "num_small_writes needs to > 2" << dendl;
       on_finish->complete(-EINVAL);
-      return;
+      return false;
     }
     this->m_bytes_allocated_cap = effective_pool_size;
     /* Log ring empty */
@@ -318,7 +318,7 @@ void WriteLog<I>::initialize_pool(Context *on_finish, pwl::DeferredContexts &lat
       this->m_free_log_entries = 0;
       lderr(cct) << "failed to initialize pool (" << this->m_log_pool_name << ")" << dendl;
       on_finish->complete(-pmemobj_tx_errno());
-      return;
+      return false;
     } TX_FINALLY {
     } TX_END;
   } else {
@@ -330,7 +330,7 @@ void WriteLog<I>::initialize_pool(Context *on_finish, pwl::DeferredContexts &lat
       lderr(cct) << "failed to open pool (" << this->m_log_pool_name << "): "
                  << pmemobj_errormsg() << dendl;
       on_finish->complete(-errno);
-      return;
+      return false;
     }
     pool_root = POBJ_ROOT(m_log_pool, struct WriteLogPoolRoot);
     if (D_RO(pool_root)->header.layout_version != RWL_POOL_VERSION) {
@@ -339,13 +339,13 @@ void WriteLog<I>::initialize_pool(Context *on_finish, pwl::DeferredContexts &lat
                  << D_RO(pool_root)->header.layout_version
                  << " expected " << RWL_POOL_VERSION << dendl;
       on_finish->complete(-EINVAL);
-      return;
+      return false;
     }
     if (D_RO(pool_root)->block_size != MIN_WRITE_ALLOC_SIZE) {
       lderr(cct) << "Pool block size is " << D_RO(pool_root)->block_size
                  << " expected " << MIN_WRITE_ALLOC_SIZE << dendl;
       on_finish->complete(-EINVAL);
-      return;
+      return false;
     }
     this->m_log_pool_size = D_RO(pool_root)->pool_size;
     this->m_flushed_sync_gen = D_RO(pool_root)->flushed_sync_gen;
@@ -369,6 +369,7 @@ void WriteLog<I>::initialize_pool(Context *on_finish, pwl::DeferredContexts &lat
     m_cache_state->clean = this->m_dirty_log_entries.empty();
     m_cache_state->empty = m_log_entries.empty();
   }
+  return true;
 }
 
 /*

diff --git a/src/librbd/cache/pwl/rwl/WriteLog.h b/src/librbd/cache/pwl/rwl/WriteLog.h
index 1d1deb2c1fcb5c85816c07665144008bbf91bfbd..dabee07d742aa1cf5f7afd6d2e8f3483aa7dda24 100644 (file)
--- a/src/librbd/cache/pwl/rwl/WriteLog.h
+++ b/src/librbd/cache/pwl/rwl/WriteLog.h
@@ -104,7 +104,7 @@ protected:
       C_BlockIORequestT *req) override;
   Context *construct_flush_entry_ctx(
         const std::shared_ptr<pwl::GenericLogEntry> log_entry) override;
-  void initialize_pool(Context *on_finish, pwl::DeferredContexts &later) override;
+  bool initialize_pool(Context *on_finish, pwl::DeferredContexts &later) override;
   void write_data_to_buffer(
       std::shared_ptr<pwl::WriteLogEntry> ws_entry,
       pwl::WriteLogCacheEntry *pmem_entry) override;

diff --git a/src/librbd/cache/pwl/ssd/WriteLog.cc b/src/librbd/cache/pwl/ssd/WriteLog.cc
index 68619fa6b3c98eaf6f549cfa88ec39b3f7f76057..e669dd6ce0020531a7f1eb2f7f0addd14f80d6e7 100644 (file)
--- a/src/librbd/cache/pwl/ssd/WriteLog.cc
+++ b/src/librbd/cache/pwl/ssd/WriteLog.cc
@@ -106,7 +106,8 @@ void WriteLog<I>::complete_read(
 }
 
 template <typename I>
-int WriteLog<I>::create_and_open_bdev() {
+bool WriteLog<I>::initialize_pool(Context *on_finish,
+                                  pwl::DeferredContexts &later) {
   CephContext *cct = m_image_ctx.cct;
 
   bdev = BlockDevice::create(cct, this->m_log_pool_name, aio_cache_cb,
@@ -155,7 +156,7 @@ bool WriteLog<I>::initialize_pool(Context *on_finish,
       m_cache_state->empty = true;
       /* TODO: filter/replace errnos that are meaningless to the caller */
       on_finish->complete(-errno);
-      return;
+      return false;
     }
 
     r = create_and_open_bdev();
@@ -204,6 +205,7 @@ bool WriteLog<I>::initialize_pool(Context *on_finish,
     m_cache_state->clean = this->m_dirty_log_entries.empty();
     m_cache_state->empty = m_log_entries.empty();
   }
+  return true;
 }
 
 template <typename I>

diff --git a/src/librbd/cache/pwl/ssd/WriteLog.h b/src/librbd/cache/pwl/ssd/WriteLog.h
index 62e1db9f35acfc0980cedc392ed0132c86ea4d2b..d96436c988510bac9f0dc3bcdcb0dad043afed39 100644 (file)
--- a/src/librbd/cache/pwl/ssd/WriteLog.h
+++ b/src/librbd/cache/pwl/ssd/WriteLog.h
@@ -63,7 +63,7 @@ protected:
   using AbstractWriteLog<ImageCtxT>::m_first_valid_entry;
   using AbstractWriteLog<ImageCtxT>::m_bytes_allocated;
 
-  void initialize_pool(Context *on_finish,
+  bool initialize_pool(Context *on_finish,
                        pwl::DeferredContexts &later) override;
   void process_work() override;
   void append_scheduled_ops(void) override;