Create function get_pg_version() to read PG_VERSION

With the recovery configuration changes in PostgreSQL 12, there will
be situations where we'll need to determine the version number from
a dormant data directory in order to determine whether to write
recovery.conf or not.
This commit is contained in:
Ian Barwick
2018-11-27 09:38:01 +09:00
parent 793d83b22c
commit 5ff3744895
2 changed files with 60 additions and 36 deletions

View File

@@ -36,6 +36,53 @@
static ControlFileInfo *get_controlfile(const char *DataDir);
int
get_pg_version(const char *data_directory, char *version_string)
{
char PgVersionPath[MAXPGPATH] = "";
FILE *fp = NULL;
char *endptr = NULL;
char file_version_string[MAX_VERSION_STRING] = "";
long file_major, file_minor;
int ret;
snprintf(PgVersionPath, MAXPGPATH, "%s/PG_VERSION", data_directory);
fp = fopen(PgVersionPath, "r");
if (fp == NULL)
{
log_warning(_("could not open file \"%s\" for reading"),
PgVersionPath);
log_detail("%s", strerror(errno));
return UNKNOWN_SERVER_VERSION_NUM;
}
file_version_string[0] = '\0';
ret = fscanf(fp, "%23s", file_version_string);
fclose(fp);
if (ret != 1 || endptr == file_version_string)
{
log_warning(_("unable to determine major version number from PG_VERSION"));
return UNKNOWN_SERVER_VERSION_NUM;
}
file_major = strtol(file_version_string, &endptr, 10);
file_minor = 0;
if (*endptr == '.')
file_minor = strtol(endptr + 1, NULL, 10);
if (version_string != NULL)
strncpy(version_string, file_version_string, MAX_VERSION_STRING);
return ((int) file_major * 10000) + ((int) file_minor * 100);
}
uint64
get_system_identifier(const char *data_directory)
{
@@ -50,6 +97,7 @@ get_system_identifier(const char *data_directory)
return system_identifier;
}
DBState
get_db_state(const char *data_directory)
{
@@ -130,14 +178,10 @@ describe_db_state(DBState state)
static ControlFileInfo *
get_controlfile(const char *DataDir)
{
char file_version_string[MAX_VERSION_STRING] = "";
ControlFileInfo *control_file_info;
FILE *fp = NULL;
int fd, ret, version_num;
char PgVersionPath[MAXPGPATH] = "";
int fd, version_num;
char ControlFilePath[MAXPGPATH] = "";
char file_version_string[64] = "";
long file_major, file_minor;
char *endptr = NULL;
void *ControlFileDataPtr = NULL;
int expected_size = 0;
@@ -154,45 +198,24 @@ get_controlfile(const char *DataDir)
* Read PG_VERSION, as we'll need to determine which struct to read
* the control file contents into
*/
snprintf(PgVersionPath, MAXPGPATH, "%s/PG_VERSION", DataDir);
fp = fopen(PgVersionPath, "r");
version_num = get_pg_version(DataDir, file_version_string);
if (fp == NULL)
if (version_num == UNKNOWN_SERVER_VERSION_NUM)
{
log_warning(_("could not open file \"%s\" for reading"),
PgVersionPath);
log_detail("%s", strerror(errno));
log_warning(_("unable to determine server version number from PG_VERSION"));
return control_file_info;
}
file_version_string[0] = '\0';
ret = fscanf(fp, "%63s", file_version_string);
fclose(fp);
if (ret != 1 || endptr == file_version_string)
if (version_num < MIN_SUPPORTED_VERSION_NUM)
{
log_warning(_("unable to determine major version number from PG_VERSION"));
log_warning(_("data directory appears to be initialised for %s"),
file_version_string);
log_detail(_("minimum supported PostgreSQL version is %s"),
MIN_SUPPORTED_VERSION);
return control_file_info;
}
file_major = strtol(file_version_string, &endptr, 10);
file_minor = 0;
if (*endptr == '.')
file_minor = strtol(endptr + 1, NULL, 10);
version_num = ((int) file_major * 10000) + ((int) file_minor * 100);
if (version_num < 90300)
{
log_warning(_("Data directory appears to be initialised for %s"), file_version_string);
return control_file_info;
}
snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
if ((fd = open(ControlFilePath, O_RDONLY | PG_BINARY, 0)) == -1)

View File

@@ -12,6 +12,7 @@
#include "postgres_fe.h"
#include "catalog/pg_control.h"
#define MAX_VERSION_STRING 24
/*
* A simplified representation of pg_control containing only those fields
* required by repmgr.
@@ -329,7 +330,7 @@ typedef struct ControlFileData11
} ControlFileData11;
extern int get_pg_version(const char *data_directory, char *version_string);
extern DBState get_db_state(const char *data_directory);
extern const char *describe_db_state(DBState state);
extern int get_data_checksum_version(const char *data_directory);