From 29ce50091d128faaabd0a4044e91a7d0da11bb8e Mon Sep 17 00:00:00 2001 From: Magnus Hagander Date: Fri, 18 May 2018 17:53:12 +0200 Subject: [PATCH] Fix error message on short read of pg_control Instead of saying "error: success", indicate that we got a working read but it was too short. --- src/backend/access/transam/xlog.c | 16 ++++++++++---- src/common/controldata_utils.c | 35 +++++++++++++++++++++++-------- 2 files changed, 38 insertions(+), 13 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 742e0e7115..0cb1e9981a 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -4475,6 +4475,7 @@ ReadControlFile(void) { pg_crc32c crc; int fd; + int r; /* * Read data... @@ -4489,10 +4490,17 @@ ReadControlFile(void) XLOG_CONTROL_FILE))); pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_READ); - if (read(fd, ControlFile, sizeof(ControlFileData)) != sizeof(ControlFileData)) - ereport(PANIC, - (errcode_for_file_access(), - errmsg("could not read from control file: %m"))); + r = read(fd, ControlFile, sizeof(ControlFileData)); + if (r != sizeof(ControlFileData)) + { + if (r < 0) + ereport(PANIC, + (errcode_for_file_access(), + errmsg("could not read from control file: %m"))); + else + ereport(PANIC, + (errmsg("could not read from control file: read %d bytes, expected %d", r, (int) sizeof(ControlFileData)))); + } pgstat_report_wait_end(); close(fd); diff --git a/src/common/controldata_utils.c b/src/common/controldata_utils.c index f1a097a974..0aabb0d864 100644 --- a/src/common/controldata_utils.c +++ b/src/common/controldata_utils.c @@ -44,6 +44,7 @@ get_controlfile(const char *DataDir, const char *progname, bool *crc_ok_p) int fd; char ControlFilePath[MAXPGPATH]; pg_crc32c crc; + int r; AssertArg(crc_ok_p); @@ -64,18 +65,34 @@ get_controlfile(const char *DataDir, const char *progname, bool *crc_ok_p) } #endif - if (read(fd, ControlFile, sizeof(ControlFileData)) != sizeof(ControlFileData)) + r = read(fd, ControlFile, sizeof(ControlFileData)); + if (r != sizeof(ControlFileData)) + { + if (r < 0) #ifndef FRONTEND - ereport(ERROR, - (errcode_for_file_access(), - errmsg("could not read file \"%s\": %m", ControlFilePath))); + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not read file \"%s\": %m", ControlFilePath))); #else - { - fprintf(stderr, _("%s: could not read file \"%s\": %s\n"), - progname, ControlFilePath, strerror(errno)); - exit(EXIT_FAILURE); - } + { + fprintf(stderr, _("%s: could not read file \"%s\": %s\n"), + progname, ControlFilePath, strerror(errno)); + exit(EXIT_FAILURE); + } #endif + else +#ifndef FRONTEND + ereport(ERROR, + (errmsg("could not read file \"%s\": read %d bytes, expected %d", + ControlFilePath, r, (int) sizeof(ControlFileData)))); +#else + { + fprintf(stderr, _("%s: could not read file \"%s\": read %d bytes, expected %d\n"), + progname, ControlFilePath, r, (int) sizeof(ControlFileData)); + exit(EXIT_FAILURE); + } +#endif + } close(fd); -- 2.40.0