Hello,
our testing team has noticed apparently wrong backup/restore error messages
like this:
pg_restore: [compress_io] could not read from input file: success
pg_dump: [directory archiver] could not write to output file: success
Such "success" messages are caused by calling strerror() after
gzread()/gzwrite() failures.
In order to properly decode errors, there should be used gzerror() instead of
strerror():
http://refspecs.linuxbase.org/LSB_2.1.0/LSB-generic/LSB-generic/zlib-gzerror-1.html
Errors should be like this:
pg_restore: [compress_io] could not read from input file: d3/2811.dat.gz:
invalid distance too far back
Attached small fix for this issue.
You can view that patch online on our github:
https://github.com/Infotecs/postgres/commit/1578f5011ad22d78ae059a4ef0924426fd6db762
--
Best regards,
Vladimir Kunschikov
Lead software developer
IDS project
InfoTeCS JSC
<http://portal.infotecs.int/company/structure/Pages/detailsDepartment.aspx?idDepartment=235&idCompany=17>
commit 1578f5011ad22d78ae059a4ef0924426fd6db762
Author: Kunshchikov Vladimir <kunshchikov....@infotecs.ru>
Date: Wed Jun 21 11:33:47 2017 +0300
fixed gz_error/strerror mishap
diff --git a/src/bin/pg_dump/compress_io.c b/src/bin/pg_dump/compress_io.c
index 631fa337e6..6e48d9d765 100644
--- a/src/bin/pg_dump/compress_io.c
+++ b/src/bin/pg_dump/compress_io.c
@@ -422,23 +422,6 @@ WriteDataToArchiveNone(ArchiveHandle *AH, CompressorState *cs,
}
-/*----------------------
- * Compressed stream API
- *----------------------
- */
-
-/*
- * cfp represents an open stream, wrapping the underlying FILE or gzFile
- * pointer. This is opaque to the callers.
- */
-struct cfp
-{
- FILE *uncompressedfp;
-#ifdef HAVE_LIBZ
- gzFile compressedfp;
-#endif
-};
-
#ifdef HAVE_LIBZ
static int hasSuffix(const char *filename, const char *suffix);
#endif
@@ -593,7 +576,7 @@ cfread(void *ptr, int size, cfp *fp)
ret = gzread(fp->compressedfp, ptr, size);
if (ret != size && !gzeof(fp->compressedfp))
exit_horribly(modulename,
- "could not read from input file: %s\n", strerror(errno));
+ "could not read from input file: %s\n", get_gz_error(fp->compressedfp));
}
else
#endif
@@ -629,7 +612,7 @@ cfgetc(cfp *fp)
{
if (!gzeof(fp->compressedfp))
exit_horribly(modulename,
- "could not read from input file: %s\n", strerror(errno));
+ "could not read from input file: %s\n", get_gz_error(fp->compressedfp));
else
exit_horribly(modulename,
"could not read from input file: end of file\n");
@@ -710,4 +693,16 @@ hasSuffix(const char *filename, const char *suffix)
suffixlen) == 0;
}
+const char *
+get_gz_error(gzFile gzf)
+{
+ int errnum;
+ static const char fallback[] = "Zlib error";
+ const int maxlen = 255;
+ const char *errmsg = gzerror(gzf, &errnum);
+ if(!errmsg || !memchr(errmsg, 0, maxlen))
+ errmsg = fallback;
+
+ return errnum == Z_ERRNO ? strerror(errno) : errmsg;
+}
#endif
diff --git a/src/bin/pg_dump/compress_io.h b/src/bin/pg_dump/compress_io.h
index 8f2e752cba..91007b042b 100644
--- a/src/bin/pg_dump/compress_io.h
+++ b/src/bin/pg_dump/compress_io.h
@@ -27,6 +27,24 @@ typedef enum
COMPR_ALG_LIBZ
} CompressionAlgorithm;
+/*----------------------
+ * Compressed stream API
+ *----------------------
+ */
+
+/*
+ * cfp represents an open stream, wrapping the underlying FILE or gzFile
+ * pointer. This is opaque to the callers.
+ */
+typedef struct
+{
+ FILE *uncompressedfp;
+#ifdef HAVE_LIBZ
+ gzFile compressedfp;
+#endif
+} cfp;
+
+
/* Prototype for callback function to WriteDataToArchive() */
typedef void (*WriteFunc) (ArchiveHandle *AH, const char *buf, size_t len);
@@ -52,10 +70,6 @@ extern void ReadDataFromArchive(ArchiveHandle *AH, int compression,
extern void WriteDataToArchive(ArchiveHandle *AH, CompressorState *cs,
const void *data, size_t dLen);
extern void EndCompressor(ArchiveHandle *AH, CompressorState *cs);
-
-
-typedef struct cfp cfp;
-
extern cfp *cfopen(const char *path, const char *mode, int compression);
extern cfp *cfopen_read(const char *path, const char *mode);
extern cfp *cfopen_write(const char *path, const char *mode, int compression);
@@ -65,5 +79,6 @@ extern int cfgetc(cfp *fp);
extern char *cfgets(cfp *fp, char *buf, int len);
extern int cfclose(cfp *fp);
extern int cfeof(cfp *fp);
+extern const char * get_gz_error(gzFile gzf);
#endif
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 79922da8ba..6196227a04 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -42,6 +42,15 @@
#include <dirent.h>
#include <sys/stat.h>
+#ifdef WRITE_ERROR_EXIT
+#undef WRITE_ERROR_EXIT
+#endif
+#define WRITE_ERROR_EXIT \
+ do { \
+ exit_horribly(modulename, "could not write to output file: %s\n", \
+ ctx && ctx->dataFH && ctx->dataFH->compressedfp? get_gz_error(ctx->dataFH->compressedfp) : strerror(errno)); \
+ } while (0)
+
typedef struct
{
/*
diff --git a/src/bin/pg_dump/pg_backup_tar.c b/src/bin/pg_dump/pg_backup_tar.c
index a2b320f371..0b7f651537 100644
--- a/src/bin/pg_dump/pg_backup_tar.c
+++ b/src/bin/pg_dump/pg_backup_tar.c
@@ -35,6 +35,7 @@
#include "pgtar.h"
#include "common/file_utils.h"
#include "fe_utils/string_utils.h"
+#include "compress_io.h"
#include <sys/stat.h>
#include <ctype.h>
@@ -556,7 +557,7 @@ _tarReadRaw(ArchiveHandle *AH, void *buf, size_t len, TAR_MEMBER *th, FILE *fh)
res = GZREAD(&((char *) buf)[used], 1, len, th->zFH);
if (res != len && !GZEOF(th->zFH))
exit_horribly(modulename,
- "could not read from input file: %s\n", strerror(errno));
+ "could not read from input file: %s\n", get_gz_error(th->zFH));
}
else
{
--
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