[LTP] [RFC] [PATCH 05/15] lib/tst_fs: Add tst_fill_fs()

[Cyril Hrubis]

Adds a simple helper to fill a filesystem.

All the funciton does is to create and write to files in a given
directory until write() fails with ENOSPC.

This is intended to be used in various filesystem related tests such as
fallocate and stress tests.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 include/tst_fs.h  |  5 +++++
 lib/tst_fill_fs.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 lib/tst_fill_fs.c

diff --git a/include/tst_fs.h b/include/tst_fs.h
index 1f6d2bab5..6fda9ee41 100644
--- a/include/tst_fs.h
+++ b/include/tst_fs.h
@@ -151,6 +151,11 @@ int tst_fill_file(const char *path, char pattern, size_t bs, size_t bcount);
  */
 const char **tst_get_supported_fs_types(void);
 
+/*
+ * Creates and writes to files on given path until write fails with ENOSPC
+ */
+void tst_fill_fs(const char *path);
+
 #ifdef TST_TEST_H__
 static inline long tst_fs_type(const char *path)
 {
diff --git a/lib/tst_fill_fs.c b/lib/tst_fill_fs.c
new file mode 100644
index 000000000..edbf5b94c
--- /dev/null
+++ b/lib/tst_fill_fs.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2017 Cyril Hrubis <chrubis@suse.cz>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TST_NO_DEFAULT_MAIN
+#include "tst_test.h"
+#include "tst_fs.h"
+
+void tst_fill_fs(const char *path)
+{
+	int i = 0;
+	char file[PATH_MAX];
+	char buf[4096];
+	size_t len;
+	ssize_t ret;
+	int fd;
+
+	for (;;) {
+		len = random() % (1024 * 102400);
+
+		snprintf(file, sizeof(file), "%s/file%i", path, i++);
+
+		tst_res(TINFO, "Creating file %s size %zu", file, len);
+
+		fd = SAFE_OPEN(file, O_WRONLY | O_CREAT, 0700);
+
+		while (len) {
+			ret = write(fd, buf, MIN(len, sizeof(buf)));
+
+			if (ret < 0) {
+				SAFE_CLOSE(fd);
+
+				if (errno != ENOSPC)
+					tst_brk(TBROK | TERRNO, "write()");
+
+				tst_res(TINFO | TERRNO, "write()");
+				return;
+			}
+
+			len -= ret;
+		}
+
+		SAFE_CLOSE(fd);
+	}
+}
-- 
2.13.0