[LTP] [PATCH] tst_device: Scan /sys/block/* for stat file

[Cyril Hrubis]

The current tst_dev_bytes_written() function works only for simple cases
where the block device is not divided into partitions. This patch fixes
that scannning the sysfiles for pattern /sys/block/*/devname/stat.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
CC: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
CC: Sumit Garg <sumit.garg@linaro.org>
---
 lib/tst_device.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/lib/tst_device.c b/lib/tst_device.c
index 10f71901d..aca769559 100644
--- a/lib/tst_device.c
+++ b/lib/tst_device.c
@@ -373,16 +373,39 @@ int tst_umount(const char *path)
 	return -1;
 }
 
+int find_stat_file(const char *dev, char *path, size_t path_len)
+{
+	const char *devname = strrchr(dev, '/') + 1;
+
+	snprintf(path, path_len, "/sys/block/%s/stat", devname);
+
+	if (!access(path, F_OK))
+		return 1;
+
+	DIR *dir = SAFE_OPENDIR(NULL, "/sys/block/");
+	struct dirent *ent;
+
+	while ((ent = readdir(dir))) {
+		snprintf(path, path_len, "/sys/block/%s/%s/stat", ent->d_name, devname);
+
+		fprintf(stderr, "%s\n", path);
+
+		if (!access(path, F_OK)) {
+			SAFE_CLOSEDIR(NULL, dir);
+			return 1;
+		}
+	}
+
+	SAFE_CLOSEDIR(NULL, dir);
+	return 0;
+}
+
 unsigned long tst_dev_bytes_written(const char *dev)
 {
-	struct stat st;
 	unsigned long dev_sec_write = 0, dev_bytes_written, io_ticks = 0;
 	char dev_stat_path[1024];
 
-	snprintf(dev_stat_path, sizeof(dev_stat_path), "/sys/block/%s/stat",
-		 strrchr(dev, '/') + 1);
-
-	if (stat(dev_stat_path, &st) != 0)
+	if (!find_stat_file(dev, dev_stat_path, sizeof(dev_stat_path)))
 		tst_brkm(TCONF, NULL, "Test device stat file: %s not found",
 			 dev_stat_path);
 
-- 
2.23.0