[Tarantool-patches] [PATCH v2 2/2] vinyl: clean-up unprocessed read views in *_build_read_views()

[Nikita Pettik <korablev@tarantool.org>]

vy_write_iterator->read_views[i].history objects are allocated on
region (see vy_write_iterator_push_rv()) during building history of the
given key. However, in case of fail of vy_write_iterator_build_history()
region is truncated but pointers to vy_write_history objects are not
nullified. As a result, they may be accessed (for instance while
finalizing write_iterator object in  vy_write_iterator_stop) which in
turn may lead to crash, segfaul or disk formatting. The same may happen
if vy_read_view_merge() fails during processing of read view array.
Let's nullify those objects in case of error takes place.

Closes #4864
---
 src/box/vy_write_iterator.c                   |  23 +++-
 src/errinj.h                                  |   1 +
 test/box/errinj.result                        |   1 +
 .../gh-4864-stmt-alloc-fail-compact.result    | 114 ++++++++++++++++++
 .../gh-4864-stmt-alloc-fail-compact.test.lua  |  48 ++++++++
 5 files changed, 184 insertions(+), 3 deletions(-)

diff --git a/src/box/vy_write_iterator.c b/src/box/vy_write_iterator.c
index 7a6a20627..910e5a062 100644
--- a/src/box/vy_write_iterator.c
+++ b/src/box/vy_write_iterator.c
@@ -790,8 +790,11 @@ next_lsn:
 	 * statement around if this is major compaction, because
 	 * there's no tuple it could overwrite.
 	 */
-	if (rc == 0 && stream->is_last_level &&
-	    stream->deferred_delete_stmt != NULL) {
+	if (rc != 0) {
+		for (int i = 0; i < stream->rv_count; ++i)
+			stream->read_views[i].history = NULL;
+	} else if (stream->is_last_level &&
+		   stream->deferred_delete_stmt != NULL) {
 		vy_stmt_unref_if_possible(stream->deferred_delete_stmt);
 		stream->deferred_delete_stmt = NULL;
 	}
@@ -834,6 +837,15 @@ vy_read_view_merge(struct vy_write_iterator *stream, struct tuple *hint,
 		rv->history = NULL;
 		return 0;
 	}
+#ifndef NDEBUG
+	struct errinj *inj =
+		errinj(ERRINJ_VY_READ_VIEW_MERGE_FAIL, ERRINJ_BOOL);
+	if (inj != NULL && inj->bparam) {
+			inj->bparam = false;
+			diag_set(OutOfMemory, 666, "malloc", "struct vy_stmt");
+			return -1;
+		}
+#endif
 	/*
 	 * Two possible hints to remove the current UPSERT.
 	 * 1. If the stream is working on the last level, we
@@ -983,8 +995,13 @@ vy_write_iterator_build_read_views(struct vy_write_iterator *stream, int *count)
 		if (rv->history == NULL)
 			continue;
 		if (vy_read_view_merge(stream, hint, rv,
-				       is_first_insert) != 0)
+				       is_first_insert) != 0) {
+			while (rv >= &stream->read_views[0]) {
+				rv->history = NULL;
+				rv--;
+			}
 			goto error;
+		}
 		assert(rv->history == NULL);
 		if (rv->tuple == NULL)
 			continue;
diff --git a/src/errinj.h b/src/errinj.h
index 383dafcb5..b7550bb5e 100644
--- a/src/errinj.h
+++ b/src/errinj.h
@@ -128,6 +128,7 @@ struct errinj {
 	_(ERRINJ_DYN_MODULE_COUNT, ERRINJ_INT, {.iparam = 0}) \
 	_(ERRINJ_INDEX_RESERVE, ERRINJ_BOOL, {.bparam = false})\
 	_(ERRINJ_VY_STMT_ALLOC, ERRINJ_INT, {.iparam = -1})\
+	_(ERRINJ_VY_READ_VIEW_MERGE_FAIL, ERRINJ_BOOL, {.bparam = false})\
 
 ENUM0(errinj_id, ERRINJ_LIST);
 extern struct errinj errinjs[];
diff --git a/test/box/errinj.result b/test/box/errinj.result
index efbb4e85e..e1b9fbe2a 100644
--- a/test/box/errinj.result
+++ b/test/box/errinj.result
@@ -68,6 +68,7 @@ evals
   - ERRINJ_VY_READ_PAGE: false
   - ERRINJ_VY_READ_PAGE_DELAY: false
   - ERRINJ_VY_READ_PAGE_TIMEOUT: 0
+  - ERRINJ_VY_READ_VIEW_MERGE_FAIL: false
   - ERRINJ_VY_RUN_DISCARD: false
   - ERRINJ_VY_RUN_FILE_RENAME: false
   - ERRINJ_VY_RUN_WRITE: false
diff --git a/test/vinyl/gh-4864-stmt-alloc-fail-compact.result b/test/vinyl/gh-4864-stmt-alloc-fail-compact.result
index 1afc02bef..403ae2899 100644
--- a/test/vinyl/gh-4864-stmt-alloc-fail-compact.result
+++ b/test/vinyl/gh-4864-stmt-alloc-fail-compact.result
@@ -121,3 +121,117 @@ errinj.set('ERRINJ_VY_STMT_ALLOC', -1)
 s:drop()
  | ---
  | ...
+
+-- All the same except for delayed vy_stmt_alloc() fail.
+-- Re-create space for the sake of test purity.
+--
+s = box.schema.space.create('test', {engine = 'vinyl'})
+ | ---
+ | ...
+_ = s:create_index('pk', {run_count_per_level = 100, page_size = 128, range_size = 1024})
+ | ---
+ | ...
+
+dump(true)
+ | ---
+ | ...
+dump()
+ | ---
+ | ...
+
+compact()
+ | ---
+ | ...
+
+dump()
+ | ---
+ | ...
+
+errinj = box.error.injection
+ | ---
+ | ...
+errinj.set('ERRINJ_VY_STMT_ALLOC', 5)
+ | ---
+ | - ok
+ | ...
+-- Compaction of first range fails, so it is re-scheduled and
+-- then successfully finishes at the second attempt.
+--
+compact()
+ | ---
+ | ...
+assert(s.index.pk:stat().range_count == 2)
+ | ---
+ | - true
+ | ...
+assert(s.index.pk:stat().run_count == 2)
+ | ---
+ | - true
+ | ...
+assert(errinj.get('ERRINJ_VY_STMT_ALLOC') == -1)
+ | ---
+ | - true
+ | ...
+errinj.set('ERRINJ_VY_STMT_ALLOC', -1)
+ | ---
+ | - ok
+ | ...
+
+s:drop()
+ | ---
+ | ...
+
+-- Once again but test that clean-up is made in case
+-- vy_read_view_merge() fails.
+--
+s = box.schema.space.create('test', {engine = 'vinyl'})
+ | ---
+ | ...
+_ = s:create_index('pk', {run_count_per_level = 100, page_size = 128, range_size = 1024})
+ | ---
+ | ...
+
+dump(true)
+ | ---
+ | ...
+dump()
+ | ---
+ | ...
+
+compact()
+ | ---
+ | ...
+
+dump()
+ | ---
+ | ...
+
+errinj = box.error.injection
+ | ---
+ | ...
+errinj.set('ERRINJ_VY_READ_VIEW_MERGE_FAIL', true)
+ | ---
+ | - ok
+ | ...
+compact()
+ | ---
+ | ...
+assert(s.index.pk:stat().range_count == 2)
+ | ---
+ | - true
+ | ...
+assert(s.index.pk:stat().run_count == 2)
+ | ---
+ | - true
+ | ...
+assert(errinj.get('ERRINJ_VY_READ_VIEW_MERGE_FAIL') == false)
+ | ---
+ | - true
+ | ...
+errinj.set('ERRINJ_VY_READ_VIEW_MERGE_FAIL', false)
+ | ---
+ | - ok
+ | ...
+s:drop()
+ | ---
+ | ...
diff --git a/test/vinyl/gh-4864-stmt-alloc-fail-compact.test.lua b/test/vinyl/gh-4864-stmt-alloc-fail-compact.test.lua
index bf70bdf75..f45fd01f3 100644
--- a/test/vinyl/gh-4864-stmt-alloc-fail-compact.test.lua
+++ b/test/vinyl/gh-4864-stmt-alloc-fail-compact.test.lua
@@ -53,3 +53,51 @@ assert(errinj.get('ERRINJ_VY_STMT_ALLOC') == -1)
 errinj.set('ERRINJ_VY_STMT_ALLOC', -1)
 
 s:drop()
+
+-- All the same except for delayed vy_stmt_alloc() fail.
+-- Re-create space for the sake of test purity.
+--
+s = box.schema.space.create('test', {engine = 'vinyl'})
+_ = s:create_index('pk', {run_count_per_level = 100, page_size = 128, range_size = 1024})
+
+dump(true)
+dump()
+
+compact()
+
+dump()
+
+errinj = box.error.injection
+errinj.set('ERRINJ_VY_STMT_ALLOC', 5)
+-- Compaction of first range fails, so it is re-scheduled and
+-- then successfully finishes at the second attempt.
+--
+compact()
+assert(s.index.pk:stat().range_count == 2)
+assert(s.index.pk:stat().run_count == 2)
+assert(errinj.get('ERRINJ_VY_STMT_ALLOC') == -1)
+errinj.set('ERRINJ_VY_STMT_ALLOC', -1)
+
+s:drop()
+
+-- Once again but test that clean-up is made in case
+-- vy_read_view_merge() fails.
+--
+s = box.schema.space.create('test', {engine = 'vinyl'})
+_ = s:create_index('pk', {run_count_per_level = 100, page_size = 128, range_size = 1024})
+
+dump(true)
+dump()
+
+compact()
+
+dump()
+
+errinj = box.error.injection
+errinj.set('ERRINJ_VY_READ_VIEW_MERGE_FAIL', true)
+compact()
+assert(s.index.pk:stat().range_count == 2)
+assert(s.index.pk:stat().run_count == 2)
+assert(errinj.get('ERRINJ_VY_READ_VIEW_MERGE_FAIL') == false)
+errinj.set('ERRINJ_VY_READ_VIEW_MERGE_FAIL', false)
+s:drop()
-- 
2.17.1