[LTP] [PATCH v5 3/4] zram/zram03: Convert into new api

[Yang Xu <xuyang2018.jy@fujitsu.com>]

Also add hot_add/hot_remove in setup/cleanup, so this case can adapt the situation that
zram module is being used by zram-generator or zram module is builtin.

zram03 case are adjuested to adapt the situation that CONFIG_ZRAM=y and can
run zram03 simultaneously.

On older kernel that doesn't support hot_remove/hot_add interface, we will use
modprobe and rmmod to detech whether zram is being used or built in kernel.
If so, we can also use zramctl -f(it doesn't depend on hot_add/hot_remove[1]) to find the free
device number.

[1]https://github.com/util-linux/util-linux/commit/0624d8406b8e8e64f7a1c6dcea7af648d99ef08d

Fixes: #888
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
---
 testcases/kernel/device-drivers/zram/zram03.c | 294 +++++++++---------
 1 file changed, 154 insertions(+), 140 deletions(-)

diff --git a/testcases/kernel/device-drivers/zram/zram03.c b/testcases/kernel/device-drivers/zram/zram03.c
index 06995fd56..d500d1c9e 100644
--- a/testcases/kernel/device-drivers/zram/zram03.c
+++ b/testcases/kernel/device-drivers/zram/zram03.c
@@ -1,27 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
- * zram: generic RAM based compressed R/W block devices
- * http://lkml.org/lkml/2010/8/9/227
- *
  * Copyright (C) 2010  Red Hat, Inc.
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/*\
+ * [Description]
  *
- * Further, this software is distributed without any warranty that it
- * is free of the rightful claim of any third person regarding
- * infringement or the like.  Any license provided herein, whether
- * implied or otherwise, applies only to this software file.  Patent
- * licenses, if any, provided herein do not apply to combinations of
- * this program with other software, or any other product whatsoever.
+ * zram: generic RAM based compressed R/W block devices
+ * http://lkml.org/lkml/2010/8/9/227
  *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
+ * This case check whether data read from zram device is consistent with
+ * thoese are written.
  */
 
 #include <sys/types.h>
@@ -29,62 +18,28 @@
 #include <sys/mman.h>
 #include <errno.h>
 #include <fcntl.h>
-#include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <stdlib.h>
+#include "tst_safe_stdio.h"
+#include "tst_test.h"
 
-#include "test.h"
-#include "safe_macros.h"
-
-char *TCID = "zram03";
-int TST_TOTAL = 1;
-
-#define PATH_ZRAM	"/sys/block/zram0"
-#define OBSOLETE_ZRAM_FILE	"/sys/block/zram0/num_reads"
-#define PATH_ZRAM_STAT	"/sys/block/zram0/stat"
-#define PATH_ZRAM_MM_STAT	"/sys/block/zram0/mm_stat"
-#define SIZE		(512 * 1024 * 1024L)
-#define DEVICE		"/dev/zram0"
-
-static int modprobe;
-
-static void set_disksize(void);
-static void write_device(void);
-static void verify_device(void);
-static void reset(void);
-static void setup(void);
-static void cleanup(void);
-static void print(char *string);
-static void dump_info(void);
-
-int main(int argc, char *argv[])
-{
-	int lc;
-
-	tst_parse_opts(argc, argv, NULL, NULL);
+#define ZRAM_CONTROL_PATH	"/sys/class/zram-control"
+#define HOT_ADD_PATH		ZRAM_CONTROL_PATH"/hot_add"
+#define HOT_REMOVE_PATH		ZRAM_CONTROL_PATH"/hot_remove"
+#define SIZE			(512 * 1024 * 1024L)
 
-	setup();
-
-	for (lc = 0; TEST_LOOPING(lc); lc++) {
-		tst_count = 0;
-
-		set_disksize();
-
-		write_device();
-		dump_info();
-		verify_device();
-
-		reset();
-		dump_info();
-	}
-	cleanup();
-	tst_exit();
-}
+static char zram_block_path[100], zram_dev_path[100];
+static int modprobe, dev_num, hot_add_flag;
+static const char *const cmd_rmmod[] = {"rmmod", "zram", NULL};
 
 static void set_disksize(void)
 {
-	tst_resm(TINFO, "create a zram device with %ld bytes in size.", SIZE);
-	SAFE_FILE_PRINTF(cleanup, PATH_ZRAM "/disksize", "%ld", SIZE);
+	char disksize_path[200];
+
+	tst_res(TINFO, "create a zram device with %ld bytes in size", SIZE);
+	sprintf(disksize_path, "%s/disksize", zram_block_path);
+	SAFE_FILE_PRINTF(disksize_path, "%ld", SIZE);
 }
 
 static void write_device(void)
@@ -92,17 +47,16 @@ static void write_device(void)
 	int fd;
 	char *s;
 
-	tst_resm(TINFO, "map this zram device into memory.");
-	fd = SAFE_OPEN(cleanup, DEVICE, O_RDWR);
-	s = SAFE_MMAP(cleanup, NULL, SIZE, PROT_READ | PROT_WRITE,
-		      MAP_SHARED, fd, 0);
+	tst_res(TINFO, "map this zram device into memory");
+	fd = SAFE_OPEN(zram_dev_path, O_RDWR);
+	s = SAFE_MMAP(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 
-	tst_resm(TINFO, "write all the memory.");
+	tst_res(TINFO, "write all the memory");
 	memset(s, 'a', SIZE - 1);
 	s[SIZE - 1] = '\0';
 
-	SAFE_MUNMAP(cleanup, s, SIZE);
-	SAFE_CLOSE(cleanup, fd);
+	SAFE_MUNMAP(s, SIZE);
+	SAFE_CLOSE(fd);
 }
 
 static void verify_device(void)
@@ -111,9 +65,9 @@ static void verify_device(void)
 	long i = 0, fail = 0;
 	char *s;
 
-	tst_resm(TINFO, "verify contents from device.");
-	fd = SAFE_OPEN(cleanup, DEVICE, O_RDONLY);
-	s = SAFE_MMAP(cleanup, NULL, SIZE, PROT_READ, MAP_PRIVATE, fd, 0);
+	tst_res(TINFO, "verify contents from device");
+	fd = SAFE_OPEN(zram_dev_path, O_RDONLY);
+	s = SAFE_MMAP(NULL, SIZE, PROT_READ, MAP_PRIVATE, fd, 0);
 
 	while (s[i] && i < SIZE - 1) {
 		if (s[i] != 'a')
@@ -121,104 +75,73 @@ static void verify_device(void)
 		i++;
 	}
 	if (i != SIZE - 1) {
-		tst_resm(TFAIL, "expect size: %ld, actual size: %ld.",
+		tst_res(TFAIL, "expect size: %ld, actual size: %ld.",
 			 SIZE - 1, i);
 	} else if (s[i] != '\0') {
-		tst_resm(TFAIL, "zram device seems not null terminated");
+		tst_res(TFAIL, "zram device seems not null terminated");
 	} else if (fail) {
-		tst_resm(TFAIL, "%ld failed bytes found.", fail);
+		tst_res(TFAIL, "%ld failed bytes found", fail);
 	} else {
-		tst_resm(TPASS, "data read from zram device is consistent "
-			 "with those are written");
+		tst_res(TPASS, "data read from zram device is consistent with those are written");
 	}
 
-	SAFE_MUNMAP(cleanup, s, SIZE);
-	SAFE_CLOSE(cleanup, fd);
+	SAFE_MUNMAP(s, SIZE);
+	SAFE_CLOSE(fd);
 }
 
 static void reset(void)
 {
-	tst_resm(TINFO, "reset it.");
-	SAFE_FILE_PRINTF(cleanup, PATH_ZRAM "/reset", "1");
-}
-
-static void setup(void)
-{
-	int retried = 0;
-
-	tst_require_root();
-
-retry:
-	if (access(PATH_ZRAM, F_OK) == -1) {
-		if (errno == ENOENT) {
-			if (retried) {
-				tst_brkm(TCONF, NULL,
-					 "system has no zram device.");
-			}
-			if (system("modprobe zram") == -1) {
-				tst_brkm(TBROK | TERRNO, cleanup,
-					 "system(modprobe zram) failed");
-			}
-			modprobe = 1;
-			retried = 1;
-			goto retry;
-		} else
-			tst_brkm(TBROK | TERRNO, NULL, "access");
-	}
-
-	tst_sig(FORK, DEF_HANDLER, cleanup);
-	TEST_PAUSE;
-}
+	char reset_path[200];
 
-static void cleanup(void)
-{
-	if (modprobe == 1 && system("rmmod zram") == -1)
-		tst_resm(TWARN | TERRNO, "system(rmmod zram) failed");
+	tst_res(TINFO, "Reset zram");
+	sprintf(reset_path, "%s/reset", zram_block_path);
+	SAFE_FILE_PRINTF(reset_path, "1");
 }
 
 static void print(char *string)
 {
 	char filename[BUFSIZ], value[BUFSIZ];
 
-	sprintf(filename, "%s/%s", PATH_ZRAM, string);
-	SAFE_FILE_SCANF(cleanup, filename, "%s", value);
-	tst_resm(TINFO, "%s is %s", filename, value);
+	tst_res(TINFO, "%s",  zram_block_path);
+	sprintf(filename, "%s/%s", zram_block_path, string);
+	SAFE_FILE_SCANF(filename, "%s", value);
+	tst_res(TINFO, "%s is %s", filename, value);
 }
 
 static void print_stat(char *nread, char *nwrite)
 {
 	char nread_val[BUFSIZ], nwrite_val[BUFSIZ];
+	char zram_stat_path[100];
 
-	SAFE_FILE_SCANF(cleanup, PATH_ZRAM_STAT, "%s %*s %*s %*s %s",
-			nread_val, nwrite_val);
-	tst_resm(TINFO, "%s from %s is %s", nread, PATH_ZRAM_STAT,
-		 nread_val);
-	tst_resm(TINFO, "%s from %s is %s", nwrite, PATH_ZRAM_STAT,
-		 nwrite_val);
+	sprintf(zram_stat_path, "/sys/block/zram%d/stat", dev_num);
+	SAFE_FILE_SCANF(zram_stat_path, "%s %*s %*s %*s %s", nread_val, nwrite_val);
+	tst_res(TINFO, "%s from %s is %s", nread, zram_stat_path, nread_val);
+	tst_res(TINFO, "%s from %s is %s", nwrite, zram_stat_path, nwrite_val);
 }
 
 static void print_mm_stat(char *orig, char *compr, char *mem, char *zero)
 {
 	char orig_val[BUFSIZ], compr_val[BUFSIZ];
 	char mem_val[BUFSIZ], zero_val[BUFSIZ];
+	char zram_mm_stat_path[100];
 
-	SAFE_FILE_SCANF(cleanup, PATH_ZRAM_MM_STAT, "%s %s %s %*s %*s %s",
+	sprintf(zram_mm_stat_path, "/sys/block/zram%d/mm_stat", dev_num);
+	SAFE_FILE_SCANF(zram_mm_stat_path, "%s %s %s %*s %*s %s",
 			orig_val, compr_val, mem_val, zero_val);
-	tst_resm(TINFO, "%s from %s is %s", orig, PATH_ZRAM_MM_STAT,
-		 orig_val);
-	tst_resm(TINFO, "%s from %s is %s", compr, PATH_ZRAM_MM_STAT,
-		compr_val);
-	tst_resm(TINFO, "%s from %s is %s", mem, PATH_ZRAM_MM_STAT,
-		 mem_val);
-	tst_resm(TINFO, "%s from %s is %s", zero, PATH_ZRAM_MM_STAT,
-		 zero_val);
+	tst_res(TINFO, "%s from %s is %s", orig, zram_mm_stat_path, orig_val);
+	tst_res(TINFO, "%s from %s is %s", compr, zram_mm_stat_path, compr_val);
+	tst_res(TINFO, "%s from %s is %s", mem, zram_mm_stat_path, mem_val);
+	tst_res(TINFO, "%s from %s is %s", zero, zram_mm_stat_path, zero_val);
 }
 
 static void dump_info(void)
 {
+	char zram_obsolete_file_path[100];
+
+	sprintf(zram_obsolete_file_path, "/sys/block/zram%d/num_reads", dev_num);
 	print("initstate");
 	print("disksize");
-	if (!access(OBSOLETE_ZRAM_FILE, F_OK)) {
+	if (!access(zram_obsolete_file_path, F_OK)) {
 		print("orig_data_size");
 		print("compr_data_size");
 		print("mem_used_total");
@@ -231,3 +154,94 @@ static void dump_info(void)
 		print_stat("num_reads", "num_writes");
 	}
 }
+
+static void run(void)
+{
+	set_disksize();
+
+	write_device();
+	dump_info();
+	verify_device();
+
+	reset();
+	dump_info();
+}
+
+static void setup(void)
+{
+	const char *const cmd_modprobe[] = {"modprobe", "zram", NULL};
+	const char *const cmd_zramctl[] = {"zramctl", "-f", NULL};
+	const char *zramctl_log_path = "zramctl.log";
+	FILE *file;
+	char line[PATH_MAX];
+	int fd;
+
+	if (!access(ZRAM_CONTROL_PATH, F_OK)) {
+		SAFE_FILE_SCANF(HOT_ADD_PATH, "%d", &dev_num);
+		hot_add_flag =1;
+		goto fill_path;
+	}
+
+	SAFE_CMD(cmd_modprobe, NULL, NULL);
+	if (access(ZRAM_CONTROL_PATH, F_OK)) {
+		file = SAFE_FOPEN("/proc/modules", "r");
+		while (fgets(line, sizeof(line), file)) {
+			if (strstr(line, "zram")) {
+				modprobe = 1;
+				break;
+			}
+		}
+		SAFE_FCLOSE(file);
+
+		if (modprobe) {
+			tst_res(TINFO, "rmmod zram before test");
+			if (tst_cmd(cmd_rmmod, NULL, NULL, TST_CMD_PASS_RETVAL)) {
+				tst_res(TINFO, "zram module may being used!");
+			} else {
+				SAFE_CMD(cmd_modprobe, NULL, NULL);
+				goto fill_path;
+			}
+		} else {
+			tst_res(TINFO, "zram module is built in kernel");
+		}
+
+		modprobe = 0;
+		tst_res(TINFO, "use zramctl -f to find free zram device");
+		fd = SAFE_OPEN(zramctl_log_path, O_CREAT | O_RDWR, 0644);
+		SAFE_CLOSE(fd);
+		if (tst_cmd(cmd_zramctl, zramctl_log_path, NULL, TST_CMD_PASS_RETVAL))
+			tst_brk(TCONF | TERRNO, "zramctl -f failed");
+		else
+			SAFE_FILE_SCANF(zramctl_log_path, "/dev/zram%d", &dev_num);
+	}
+
+fill_path:
+	sprintf(zram_block_path, "/sys/block/zram%d", dev_num);
+	sprintf(zram_dev_path, "/dev/zram%d", dev_num);
+}
+
+static void cleanup(void)
+{
+	if (hot_add_flag)
+		SAFE_FILE_PRINTF(HOT_REMOVE_PATH, "%d", dev_num);
+
+	if (modprobe)
+		SAFE_CMD(cmd_rmmod, NULL, NULL);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.setup = setup,
+	.cleanup = cleanup,
+	.needs_root = 1,
+	.needs_tmpdir = 1,
+	.needs_drivers = (const char *const []) {
+		"zram",
+		NULL
+	},
+	.needs_cmds = (const char *[]) {
+		"modprobe",
+		"rmmod",
+		NULL
+	}
+};
-- 
2.23.0


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