From 08c6d42c8c63c62aeaaf71cd6375baef798c5924 Mon Sep 17 00:00:00 2001 From: Noah Misch Date: Sun, 12 Mar 2017 19:35:31 -0400 Subject: [PATCH] Fix pg_file_write() error handling. Detect fclose() failures; given "ln -s /dev/full $PGDATA/devfull", "pg_file_write('devfull', 'x', true)" now fails as it should. Don't leak a stream when fwrite() fails. Remove a born-ineffective test that aimed to skip zero-length writes. Back-patch to 9.2 (all supported versions). --- contrib/adminpack/adminpack.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/contrib/adminpack/adminpack.c b/contrib/adminpack/adminpack.c index ea781a0a5a..67b4a47f4a 100644 --- a/contrib/adminpack/adminpack.c +++ b/contrib/adminpack/adminpack.c @@ -136,10 +136,10 @@ pg_file_write(PG_FUNCTION_ARGS) (ERRCODE_DUPLICATE_FILE, errmsg("file \"%s\" exists", filename))); - f = fopen(filename, "wb"); + f = AllocateFile(filename, "wb"); } else - f = fopen(filename, "ab"); + f = AllocateFile(filename, "ab"); if (!f) ereport(ERROR, @@ -147,16 +147,11 @@ pg_file_write(PG_FUNCTION_ARGS) errmsg("could not open file \"%s\" for writing: %m", filename))); - if (VARSIZE(data) != 0) - { - count = fwrite(VARDATA(data), 1, VARSIZE(data) - VARHDRSZ, f); - - if (count != VARSIZE(data) - VARHDRSZ) - ereport(ERROR, - (errcode_for_file_access(), - errmsg("could not write file \"%s\": %m", filename))); - } - fclose(f); + count = fwrite(VARDATA(data), 1, VARSIZE(data) - VARHDRSZ, f); + if (count != VARSIZE(data) - VARHDRSZ || FreeFile(f)) + ereport(ERROR, + (errcode_for_file_access(), + errmsg("could not write file \"%s\": %m", filename))); PG_RETURN_INT64(count); }