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authorThomas Munro2023-10-15 21:43:47 +0000
committerThomas Munro2023-10-15 21:47:01 +0000
commita56fe5cf07fea61f8d79570633298951697a3f72 (patch)
tree935d8157a68ca19dfe94ef4642e2777cb8930cd8
parent0834df90942d229ecc8bc36bfe5fe5f3ce26a4c9 (diff)
Acquire ControlFileLock in relevant SQL functions.
Commit dc7d70ea added functions that read the control file, but didn't acquire ControlFileLock. With unlucky timing, file systems that have weak interlocking like ext4 and ntfs could expose partially overwritten contents, and the checksum would fail. Back-patch to all supported releases. Reviewed-by: David Steele <david@pgmasters.net> Reviewed-by: Anton A. Melnikov <aamelnikov@inbox.ru> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/20221123014224.xisi44byq3cf5psi%40awork3.anarazel.de
-rw-r--r--src/backend/utils/misc/pg_controldata.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/src/backend/utils/misc/pg_controldata.c b/src/backend/utils/misc/pg_controldata.c
index 209a20a8827..d84606bc9e9 100644
--- a/src/backend/utils/misc/pg_controldata.c
+++ b/src/backend/utils/misc/pg_controldata.c
@@ -24,6 +24,7 @@
#include "common/controldata_utils.h"
#include "funcapi.h"
#include "miscadmin.h"
+#include "storage/lwlock.h"
#include "utils/builtins.h"
#include "utils/pg_lsn.h"
#include "utils/timestamp.h"
@@ -54,7 +55,9 @@ pg_control_system(PG_FUNCTION_ARGS)
tupdesc = BlessTupleDesc(tupdesc);
/* read the control file */
+ LWLockAcquire(ControlFileLock, LW_SHARED);
ControlFile = get_controlfile(DataDir, &crc_ok);
+ LWLockRelease(ControlFileLock);
if (!crc_ok)
ereport(ERROR,
(errmsg("calculated CRC checksum does not match value stored in file")));
@@ -132,7 +135,9 @@ pg_control_checkpoint(PG_FUNCTION_ARGS)
tupdesc = BlessTupleDesc(tupdesc);
/* Read the control file. */
+ LWLockAcquire(ControlFileLock, LW_SHARED);
ControlFile = get_controlfile(DataDir, &crc_ok);
+ LWLockRelease(ControlFileLock);
if (!crc_ok)
ereport(ERROR,
(errmsg("calculated CRC checksum does not match value stored in file")));
@@ -235,7 +240,9 @@ pg_control_recovery(PG_FUNCTION_ARGS)
tupdesc = BlessTupleDesc(tupdesc);
/* read the control file */
+ LWLockAcquire(ControlFileLock, LW_SHARED);
ControlFile = get_controlfile(DataDir, &crc_ok);
+ LWLockRelease(ControlFileLock);
if (!crc_ok)
ereport(ERROR,
(errmsg("calculated CRC checksum does not match value stored in file")));
@@ -300,7 +307,9 @@ pg_control_init(PG_FUNCTION_ARGS)
tupdesc = BlessTupleDesc(tupdesc);
/* read the control file */
+ LWLockAcquire(ControlFileLock, LW_SHARED);
ControlFile = get_controlfile(DataDir, &crc_ok);
+ LWLockRelease(ControlFileLock);
if (!crc_ok)
ereport(ERROR,
(errmsg("calculated CRC checksum does not match value stored in file")));