Commit 6c26df84 authored by Yosry Ahmed's avatar Yosry Ahmed Committed by Andrew Morton
Browse files

selftests: cgroup: return -errno from cg_read()/cg_write() on failure 

Currently, cg_read()/cg_write() returns 0 on success and -1 on failure.
Modify them to return the -errno on failure.

Link: https://lkml.kernel.org/r/20220425190040.2475377-3-yosryahmed@google.com


Signed-off-by: default avatarYosry Ahmed <yosryahmed@google.com>
Acked-by: default avatarShakeel Butt <shakeelb@google.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Acked-by: default avatarRoman Gushchin <roman.gushchin@linux.dev>
Cc: Chen Wandun <chenwandun@huawei.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Michal Koutn" <mkoutny@suse.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 94968384

tools/testing/selftests/cgroup/cgroup_util.c

+19 −25
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include "cgroup_util.h"

#include "../clone3/clone3_selftests.h"



/* Returns read len on success, or -errno on failure. */

static ssize_t read_text(const char *path, char *buf, size_t max_len)

{

	ssize_t len;
@@ -26,35 +27,29 @@ static ssize_t read_text(const char *path, char *buf, size_t max_len) 


	fd = open(path, O_RDONLY);

	if (fd < 0)

		return fd;

		return -errno;



	len = read(fd, buf, max_len - 1);

	if (len < 0)

		goto out;



	if (len >= 0)

		buf[len] = 0;

out:



	close(fd);

	return len;

	return len < 0 ? -errno : len;

}



/* Returns written len on success, or -errno on failure. */

static ssize_t write_text(const char *path, char *buf, ssize_t len)

{

	int fd;



	fd = open(path, O_WRONLY | O_APPEND);

	if (fd < 0)

		return fd;

		return -errno;



	len = write(fd, buf, len);

	if (len < 0) {

		close(fd);

		return len;

	}



	close(fd);



	return len;

	return len < 0 ? -errno : len;

}



char *cg_name(const char *root, const char *name)
@@ -87,16 +82,16 @@ char *cg_control(const char *cgroup, const char *control) 
	return ret;

}



/* Returns 0 on success, or -errno on failure. */

int cg_read(const char *cgroup, const char *control, char *buf, size_t len)

{

	char path[PATH_MAX];

	ssize_t ret;



	snprintf(path, sizeof(path), "%s/%s", cgroup, control);



	if (read_text(path, buf, len) >= 0)

		return 0;



	return -1;

	ret = read_text(path, buf, len);

	return ret >= 0 ? 0 : ret;

}



int cg_read_strcmp(const char *cgroup, const char *control,
@@ -177,17 +172,15 @@ long cg_read_lc(const char *cgroup, const char *control) 
	return cnt;

}



/* Returns 0 on success, or -errno on failure. */

int cg_write(const char *cgroup, const char *control, char *buf)

{

	char path[PATH_MAX];

	ssize_t len = strlen(buf);

	ssize_t len = strlen(buf), ret;



	snprintf(path, sizeof(path), "%s/%s", cgroup, control);



	if (write_text(path, buf, len) == len)

		return 0;



	return -1;

	ret = write_text(path, buf, len);

	return ret == len ? 0 : ret;

}



int cg_find_unified_root(char *root, size_t len)
@@ -545,7 +538,8 @@ ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t 
	else

		snprintf(path, sizeof(path), "/proc/%d/%s", pid, item);



	return read_text(path, buf, size);

	size = read_text(path, buf, size);

	return size < 0 ? -1 : size;

}



int proc_read_strstr(int pid, bool thread, const char *item, const char *needle)