diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/cache/catcache.c | 9 | ||||
| -rw-r--r-- | src/backend/utils/cache/relcache.c | 6 |
2 files changed, 15 insertions, 0 deletions
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index a8658116283..0b27bc034c0 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -24,6 +24,7 @@ #ifdef CATCACHE_STATS #include "storage/ipc.h" /* for on_proc_exit */ #endif +#include "storage/lmgr.h" #include "utils/builtins.h" #include "utils/fmgroids.h" #include "utils/memutils.h" @@ -1009,8 +1010,16 @@ InitCatCachePhase2(CatCache *cache, bool touch_index) { Relation idesc; + /* + * We must lock the underlying catalog before opening the index to + * avoid deadlock, since index_open could possibly result in reading + * this same catalog, and if anyone else is exclusive-locking this + * catalog and index they'll be doing it in that order. + */ + LockRelationOid(cache->cc_reloid, AccessShareLock); idesc = index_open(cache->cc_indexoid, AccessShareLock); index_close(idesc, AccessShareLock); + UnlockRelationOid(cache->cc_reloid, AccessShareLock); } } diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index f6853899b3c..59648a5ddec 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -1541,6 +1541,12 @@ RelationClose(Relation relation) * We assume that at the time we are called, we have at least AccessShareLock * on the target index. (Note: in the calls from RelationClearRelation, * this is legitimate because we know the rel has positive refcount.) + * + * If the target index is an index on pg_class or pg_index, we'd better have + * previously gotten at least AccessShareLock on its underlying catalog, + * else we are at risk of deadlock against someone trying to exclusive-lock + * the heap and index in that order. This is ensured in current usage by + * only applying this to indexes being opened or having positive refcount. */ static void RelationReloadClassinfo(Relation relation) |