From a4e0846e34ed4c8255a6bab1ca675c73535466fd Mon Sep 17 00:00:00 2001 From: Ayush Tiwari Date: Sat, 12 Sep 2026 13:10:18 +0530 Subject: [PATCH v1 2/2] Avoid core dumps for WAL disk-full failures Use errnocoredump_on_errno(ENOSPC) for selected WAL and control-file I/O errors that report or may be promoted to PANIC. They retain existing PANIC handling, while ENOSPC terminates without asking the operating system for a core file. Other errno values, corruption failures, and internal-invariant PANICs still use abort(). Cover WAL segment initialization, copies, writes, syncs, opens and closes, control-file creation and updates, and WAL reads during recovery. Control-file I/O can run in the postmaster. postgresql.conf has already been read before its initial control-file read, so the override is available there. During crash reinitialization, the postmaster reaches the control-file read only after all child processes have exited. --- src/backend/access/transam/xlog.c | 21 +++++++++++++++++++++ src/backend/access/transam/xlogrecovery.c | 2 ++ src/common/controldata_utils.c | 4 ++++ 3 files changed, 27 insertions(+) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index c7a8d64c1f7..5c8dae6deaa 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -2477,6 +2477,7 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible) errno = save_errno; ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not write to log file \"%s\" at offset %u, length %zu: %m", xlogfname, startoffset, nleft))); } @@ -3273,6 +3274,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli, if (errno != ENOENT) ereport(ERROR, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not open file \"%s\": %m", path))); } else @@ -3298,6 +3300,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli, if (fd < 0) ereport(ERROR, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not create file \"%s\": %m", tmppath))); /* Measure I/O timing when initializing segment */ @@ -3351,6 +3354,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli, ereport(ERROR, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not write to file \"%s\": %m", tmppath))); } @@ -3373,6 +3377,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli, errno = save_errno; ereport(ERROR, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not fsync file \"%s\": %m", tmppath))); } pgstat_report_wait_end(); @@ -3383,6 +3388,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli, if (close(fd) != 0) ereport(ERROR, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not close file \"%s\": %m", tmppath))); /* @@ -3453,6 +3459,7 @@ XLogFileInit(XLogSegNo logsegno, TimeLineID logtli) if (fd < 0) ereport(ERROR, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not open file \"%s\": %m", path))); return fd; } @@ -3571,6 +3578,7 @@ XLogFileCopy(TimeLineID destTLI, XLogSegNo destsegno, if (pg_fsync(fd) != 0) ereport(data_sync_elevel(ERROR), (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not fsync file \"%s\": %m", tmppath))); pgstat_report_wait_end(); @@ -3685,6 +3693,7 @@ XLogFileOpen(XLogSegNo segno, TimeLineID tli) if (fd < 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not open file \"%s\": %m", path))); return fd; @@ -3718,6 +3727,7 @@ XLogFileClose(void) errno = save_errno; ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not close file \"%s\": %m", xlogfname))); } @@ -4378,6 +4388,7 @@ WriteControlFile(void) if (fd < 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not create file \"%s\": %m", XLOG_CONTROL_FILE))); @@ -4390,6 +4401,7 @@ WriteControlFile(void) errno = ENOSPC; ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not write to file \"%s\": %m", XLOG_CONTROL_FILE))); } @@ -4399,6 +4411,7 @@ WriteControlFile(void) if (pg_fsync(fd) != 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not fsync file \"%s\": %m", XLOG_CONTROL_FILE))); pgstat_report_wait_end(); @@ -4406,6 +4419,7 @@ WriteControlFile(void) if (close(fd) != 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not close file \"%s\": %m", XLOG_CONTROL_FILE))); } @@ -4426,6 +4440,7 @@ ReadControlFile(void) if (fd < 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not open file \"%s\": %m", XLOG_CONTROL_FILE))); @@ -4436,6 +4451,7 @@ ReadControlFile(void) if (r < 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not read file \"%s\": %m", XLOG_CONTROL_FILE))); else @@ -5602,6 +5618,7 @@ BootStrapXLOG(uint32 data_checksum_version) errno = ENOSPC; ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not write bootstrap write-ahead log file: %m"))); } pgstat_report_wait_end(); @@ -5610,12 +5627,14 @@ BootStrapXLOG(uint32 data_checksum_version) if (pg_fsync(openLogFile) != 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not fsync bootstrap write-ahead log file: %m"))); pgstat_report_wait_end(); if (close(openLogFile) != 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not close bootstrap write-ahead log file: %m"))); openLogFile = -1; @@ -9407,6 +9426,7 @@ assign_wal_sync_method(int new_wal_sync_method, void *extra) errno = save_errno; ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not fsync file \"%s\": %m", xlogfname))); } @@ -9485,6 +9505,7 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli) errno = save_errno; ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg(msg, xlogfname))); } diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c index fff8d57ac61..3e80cea942a 100644 --- a/src/backend/access/transam/xlogrecovery.c +++ b/src/backend/access/transam/xlogrecovery.c @@ -3415,6 +3415,7 @@ retry: errno = save_errno; ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen), (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not read from WAL segment %s, LSN %X/%08X, offset %u: %m", fname, LSN_FORMAT_ARGS(targetPagePtr), readOff))); @@ -4287,6 +4288,7 @@ XLogFileRead(XLogSegNo segno, TimeLineID tli, if (errno != ENOENT || !notfoundOk) /* unexpected failure? */ ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not open file \"%s\": %m", path))); return -1; } diff --git a/src/common/controldata_utils.c b/src/common/controldata_utils.c index 0e8e03c566c..4c566b46b88 100644 --- a/src/common/controldata_utils.c +++ b/src/common/controldata_utils.c @@ -223,6 +223,7 @@ update_controlfile(const char *DataDir, if ((fd = BasicOpenFile(ControlFilePath, O_RDWR | PG_BINARY)) < 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not open file \"%s\": %m", ControlFilePath))); #else @@ -244,6 +245,7 @@ update_controlfile(const char *DataDir, #ifndef FRONTEND ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not write file \"%s\": %m", ControlFilePath))); #else @@ -261,6 +263,7 @@ update_controlfile(const char *DataDir, if (pg_fsync(fd) != 0) ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not fsync file \"%s\": %m", ControlFilePath))); pgstat_report_wait_end(); @@ -275,6 +278,7 @@ update_controlfile(const char *DataDir, #ifndef FRONTEND ereport(PANIC, (errcode_for_file_access(), + errnocoredump_on_errno(ENOSPC), errmsg("could not close file \"%s\": %m", ControlFilePath))); #else -- 2.34.1