pg_upgrade: Report full disk better

Previously, pg_upgrade would abort copy_file() on a short write without
setting errno, which the caller would report as an error with the
message "Success".  We assume ENOSPC in that case, as we do elsewhere in
the code.  Also set errno in some other error cases in copy_file() to
avoid bogus "Success" error messages.

This was broken in 6b711cf37c228749b6a8cef50e16e3c587d18dd4, so 9.2 and
before are OK.

diff --git a/contrib/pg_upgrade/file.c b/contrib/pg_upgrade/file.c
index dfeb79f255d9524af7bd6b06961746b1dd67fcb8..c198e91ce15dd61fdd852454bbeb6a1d390f7e56 100644 (file)
--- a/contrib/pg_upgrade/file.c
+++ b/contrib/pg_upgrade/file.c
@@ -136,16 +136,22 @@ copy_file(const char *srcfile, const char *dstfile, bool force)
        int                     save_errno = 0;
 
        if ((srcfile == NULL) || (dstfile == NULL))
+       {
+               errno = EINVAL;
                return -1;
+       }
 
        if ((src_fd = open(srcfile, O_RDONLY, 0)) < 0)
                return -1;
 
        if ((dest_fd = open(dstfile, O_RDWR | O_CREAT | (force ? 0 : O_EXCL), S_IRUSR | S_IWUSR)) < 0)
        {
+               save_errno = errno;
+
                if (src_fd != 0)
                        close(src_fd);
 
+               errno = save_errno;
                return -1;
        }
 
@@ -170,6 +176,9 @@ copy_file(const char *srcfile, const char *dstfile, bool force)
 
                if (write(dest_fd, buffer, nbytes) != nbytes)
                {
+                       /* if write didn't set errno, assume problem is no disk space */
+                       if (errno == 0)
+                               errno = ENOSPC;
                        save_errno = errno;
                        ret = -1;
                        break;