[PATCH 1/4] vinyl: fix EQ check in run iterator
Vladimir Davydov
vdavydov.dev at gmail.com
Tue May 15 17:08:37 MSK 2018
vy_run_iterator_seek() is supposed to check that the resulting statement
matches the search key in case of ITER_EQ, but if the search key lies at
the beginning of the slice, it doesn't. As a result, vy_point_lookup()
may fail to find an existing tuple as demonstrated below.
Suppose we are looking for key {10} in the primary index which consists
of an empty mem and two runs:
run 1: DELETE{15}
run 2: INSERT{10}
vy_run_iterator_next() returns DELETE{15} for run 1 because of the
missing EQ check and vy_point_lookup() stops at run 1 (since the
terminal statement is found) and mistakenly returns NULL.
The issue manifests itself as crash in vinyl_iterator_secondary_next(),
when we fail to find the tuple in the primary index corresponding to a
statement found in a secondary index.
Part of #3393
---
src/box/vy_run.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/src/box/vy_run.c b/src/box/vy_run.c
index 587cb002..8c922895 100644
--- a/src/box/vy_run.c
+++ b/src/box/vy_run.c
@@ -1316,6 +1316,7 @@ vy_run_iterator_seek(struct vy_run_iterator *itr,
{
const struct key_def *cmp_def = itr->cmp_def;
struct vy_slice *slice = itr->slice;
+ const struct tuple *check_eq_key = NULL;
int cmp;
if (slice->begin != NULL &&
@@ -1340,6 +1341,8 @@ vy_run_iterator_seek(struct vy_run_iterator *itr,
return 0;
}
if (cmp < 0 || (cmp == 0 && iterator_type != ITER_GT)) {
+ if (iterator_type == ITER_EQ)
+ check_eq_key = key;
iterator_type = ITER_GE;
key = slice->begin;
}
@@ -1365,7 +1368,15 @@ vy_run_iterator_seek(struct vy_run_iterator *itr,
}
}
- return vy_run_iterator_do_seek(itr, iterator_type, key, ret);
+ if (vy_run_iterator_do_seek(itr, iterator_type, key, ret) != 0)
+ return -1;
+
+ if (check_eq_key != NULL && *ret != NULL &&
+ vy_stmt_compare(check_eq_key, *ret, cmp_def) != 0) {
+ vy_run_iterator_stop(itr);
+ *ret = NULL;
+ }
+ return 0;
}
/* }}} vy_run_iterator vy_run_iterator support functions */
--
2.11.0
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