Zram handle util

I want hear your opinions.
Several days ago, i writed zramctl util (on C++) for have useful app for setup zrams..

Code hosted her: https://github.com/Nefelim4ag/zramctl

Examples:
zramctl find # return name of first free device (zram0) zramctl find 1024M lz4 4 # (i not implement -? options now)
# 4 - threads
# setup and return name of device (zram1)
zramctl reset zram0 zram1 ...

I want to port it on C and try include it in util-linux, like losetup. It has a sense? What do you think?

By glance it seems a good utility would be able to integrate with udev and systemd, it should have add, remove, and possibly modify method. I would prefer the command to list what is current status of zram devices when nothing else is instructed. And of course manual page is needed. See util-linux/Documentation/howto-man-page.txt file to get manual done.

Without any investigation I have no idea what should be done with systemd integration. The zramctl might need a systemd service file, and possibly some sort of configuration file to setup the devices at boot desired way. Or something totally different. I am sure there is someone who knows what should be done, and with a bit of luck the mail archive discussion I pointed out has an answer to this already. --
Sami Kerola
http://www.iki.fi/kerolasa/

By glance it seems a good utility would be able to integrate with udev and systemd, it should have add, remove, and possibly modify method. I would prefer the command to list what is current status of zram devices when nothing else is instructed. And of course manual page is needed. See util-linux/Documentation/howto-man-page.txt file to get manual done.

Without any investigation I have no idea what should be done with systemd integration. The zramctl might need a systemd service file, and possibly some sort of configuration file to setup the devices at boot desired way. Or something totally different. I am sure there is someone who knows what should be done, and with a bit of luck the mail archive discussion I pointed out has an answer to this already. --
Sami Kerola
http://www.iki.fi/kerolasa/

Good time of day.
I want hear your opinions.
Several days ago, i writed zramctl util (on C++) for have useful app for setup zrams..
Code hosted her: https://github.com/Nefelim4ag/zramctl

Examples:
zramctl find # return name of first free device (zram0) zramctl find 1024M lz4 4 # (i not implement -? options now)
# 4 - threads
# setup and return name of device (zram1)
zramctl reset zram0 zram1 ...

I want to port it on C and try include it in util-linux, like losetup. It has a sense? What do you think?

Quoted 14 lines · Timofey Titovets

Good time of day.
I want hear your opinions.
Several days ago, i writed zramctl util (on C++) for have useful app for setup zrams..
Code hosted her: https://github.com/Nefelim4ag/zramctl

Examples:
zramctl find # return name of first free device (zram0) zramctl find 1024M lz4 4 # (i not implement -? options now)
# 4 - threads
# setup and return name of device (zram1)
zramctl reset zram0 zram1 ...

Quoted 2 lines

I want to port it on C and try include it in util-linux, like losetup. It has a sense? What do you think?

Minchan, any thoughts in keeping this sort of utility in the kernel tree? Perhaps tools/zram/? No idea if the code is suitable to consider right away, but it kinda makes sense.

Thanks,
Davidlohr

First of all, Thanks for your effor, Timofey!

Adding such userspace tool in kernel src directory doesn't make sense. If we wanted it, there are tons of user tools in kernel src directory so IMHO, util-linux is better place.

Good time of day,
I spend some time and rewrite zramctl for util-linux.

Please review code and man pages, i think what i can do it better. If you have any suggestion, say it out.

Can be pulled from:
https://github.com/Nefelim4ag/util-linux

For detail see man pages zramctl.8

----

 sys-utils/Makemodule.am |   5 +
 sys-utils/zramctl.8     |  92 ++++++++++++++
 sys-utils/zramctl.c     | 319
++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 416 insertions(+)

sys-utils/Makemodule.am +5 -0

index 68fd030..5d70c51 100644
@@ -172,6 +172,11 @@ eject_CFLAGS = $(AM_CFLAGS) -I$(ul_libmount_incdir)
 dist_man_MANS += sys-utils/eject.1
 endif
 
+sbin_PROGRAMS += zramctl
+dist_man_MANS += sys-utils/zramctl.8
+zramctl_SOURCES = sys-utils/zramctl.c
+zramctl_LDADD = $(LDADD) libcommon.la libsmartcols.la
+zramctl_CFLAGS = $(AM_CFLAGS) -I$(ul_libsmartcols_incdir)
 
 if BUILD_LOSETUP
 sbin_PROGRAMS += losetup

sys-utils/zramctl.8 new file +50 -0

new file mode 100644
index 0000000..4da209d
@@ -0,0 +1,92 @@
+.TH ZRAMCTL 8 "July 2014" "util-linux" "System Administration"
+.SH NAME
+zramctl \- set up and control zram devices
+.SH SYNOPSIS
+.ad l
+Get info:
+.sp
+.in +5
+.B zramctl
+.sp
+.in -5
+Reset zram:
+.sp
+.in +5
+.B "zramctl \-r"
+.IR zramdev
+.sp
+.in -5
+Print name of first unused zram device:
+.sp
+.in +5
+.B "zramctl \-f"
+.sp
+.in -5
+Setup zram device:
+.sp
+.in +5
+.B zramctl
+.RB { \-f\ [ \-d\ \fIzramdev\fP] }
+.RB [ \-s
+.IR size ]
+.RB \ [ \-t
+.IR number ]
+.in +8
+.RB [ \-a
+.IR algorithm ]
+.sp
+.in -13
+.ad b
+.SH DESCRIPTION
+.B zramctl
+is used to fast setup zram devices parametrs, to reset zram devices and to
+query the status of a used zram devices.
+If no option is given, all zram devices are shown.
+
+
+.SH OPTIONS
+
+.IP "\fB\-s, \-\-size\fP \fIsize\fP
+force zram driver to reread size of the file associated with the specified

zram device
++The \fIsize\fR arguments may be followed by the multiplicative ++suffixes 128K 512M, 1G.
+.IP "\fB\-r, \-\-reset\fP \fIzramdev\fP"
+Reset options specified zram device(s). Zram device setting can be changed only

sys-utils/zramctl.8 new file +38 -0

+after reset.
+.IP "\fB\-f, \-\-find\fP"
+find the first unused zram device. If a
+.R \-s \fIsize\fR
+argument is present, use this device.
+.IP "\fB\-h, \-\-help\fP"
+print help
+.IP "\fB\-t, \-\-threads \fInumber\fP"
+Set number of maximum compress streams what used for device.
+.IP "\fB\-a, \-\-alg \fI{lzo|lz4}\fP""
+Set compress algorithm used for compress data in zram device.
+
+.SH RETURN VALUE
+.B zramctl
+returns 0 on success, nonzero on failure.
+
+.SH FILES
+.TP
+.I /dev/zram[0..N]
+zram block devices
+
+.SH EXAMPLE
+The following commands can be used as an example of using the zram device.
+.nf
+.IP
+# zramctl --find --size 1024M
+/dev/zram0
+# mkswap /dev/zram0
+# swapon /dev/zram0
+ ...
+# swapoff /dev/zram0
+# zramctl --reset /dev/zram0
+.fi
+.SH AUTHORS
+Timofey Titovets <[email protected]>
+.SH AVAILABILITY
+The zramctl command is part of the util-linux package and is available from
+ftp://ftp.kernel.org/pub/linux/utils/util-linux/.

sys-utils/zramctl.c new file +41 -0

new file mode 100644
index 0000000..6ddee9b
@@ -0,0 +1,319 @@
+/*
+ * zramctl - purpose of it
+ *
+ * Copyright (c) 20nn  Example Commercial, Inc
+ * Written by Timofey Titovets <[email protected]>
+ *
+ * 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.
+ *
+ * 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.  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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "c.h"
+#include "closestream.h"
+#include "nls.h"
+
+static inline int zram_exist(char *name)
+{
+	struct stat info;
+	char path[16] = "/dev/";
+	strncat(path, name, 8);
+	if(stat(path, &info) != 0 )
+		return 0;
+	if (info.st_mode&S_IFBLK)
+		return 1;

sys-utils/zramctl.c new file +17 -0

+	file = fopen(p, "r");
+	if (file == NULL) {
+		fprintf(stderr,_("can't open !%s!\n"), path);
+		return -1;
+	}
+
+	while (1) {
+		ch = fgetc(file);
+		if (ch == EOF || ch == '\n')
+			break;
+		else
+			data[i]=ch;
+		i++;
+	}
+	fclose(file);
+
+	return 0;

sys-utils/zramctl.c new file +4 -0

+
+	if (disksize[0] == '0')
+		return 0;
+

sys-utils/zramctl.c new file +5 -0

+}
+
+static inline int write_file(char *path, char *data)
+{
+	FILE *file;

sys-utils/zramctl.c new file +81 -0

+	for (i=0;;i++) {
+		char name[8] = "zram";
+		char num[4];
+		char *pos;
+		sprintf(num,"%i",i);
+		strncat(name, num, 8);
+		if(!zram_exist(name))
+			break;
+		if(!used(name))
+			continue;
+		get_value(name, disksize, "disksize");
+		get_value(name, orig_data_size, "orig_data_size");
+		get_value(name, compr_data_size, "compr_data_size");
+		get_value(name, comp_algorithm, "comp_algorithm");
+		pos = strstr(comp_algorithm, "[lzo]");
+		if (pos == NULL) {
+			pos = strstr(comp_algorithm, "[lz4]");
+			if (pos == NULL)
+				strncpy(comp_algorithm,"-", 2);
+			else
+				strncpy(comp_algorithm, "lz4", 4);
+		} else
+			strncpy(comp_algorithm, "lzo", 4);
+		get_value(name, max_comp_streams, "max_comp_streams");
+		printf(table,
+			name,
+			disksize,
+			orig_data_size,
+			compr_data_size,
+			comp_algorithm,
+			max_comp_streams
+		      );
+	}
+
+	return 0;
+	goto fail;
+fail:
+	printf("Zram module not loaded");
+	return -1;
+}
+
+static inline char *find(void)
+{
+	char *ret = NULL;
+	for (unsigned i=0;;i++) {
+		char name[8] = "zram";
+		char num[4];
+
+		sprintf(num,"%i",i);
+		strncat(name, num, 4);
+		if (!zram_exist(name))
+			break;
+		else	//if enough one dir founded -> module loaded
+			ret = "USED";
+
+		if (used(name) == 0) {
+			ret = name;
+			break;
+		}
+	}
+
+		return ret;
+}
+
+
+
+static inline void usage(FILE *out)
+{
+	fputs(USAGE_HEADER, out);
+	fprintf(out, _(" %s [-d zramX|-f] -s 64M -a lz4 -t 16\n"), "zramctl");
+	fputs(USAGE_OPTIONS, out);
+	fputs(_(" <no args>             return status of used devices\n"), out);
+	fputs(_(" -f, --find            find free device\n"), out);
+	fputs(_(" -d, --device [name]   specify device: zramX\n"), out);
+	fputs(_(" -r, --reset  [name]   reset specified device\n"), out);
+	fputs(_(" -s, --size [size]     device size: 131072, 1024M...\n"), out);
+	fputs(_(" -a, --alg [lzo|lz4]   compress algorithm\n"), out);
+	fputs(_(" -t, --threads [0<num] number of compress streams\n"), out);
+	fputs(USAGE_SEPARATOR, out);
+	fputs(USAGE_HELP, out);
+	fputs(USAGE_VERSION, out);

sys-utils/zramctl.c new file +20 -0

+	char threads[5] = "1";
+	unsigned f = 0;
+
+	static const struct option longopts[] = {
+		{"find", no_argument, NULL, 'f'},
+		{"device", required_argument, NULL, 'd'},
+		{"size", required_argument, NULL, 's'},
+		{"alg", required_argument, NULL, 'a'},
+		{"threads", required_argument, NULL, 't'},
+		{"reset", required_argument, NULL, 'r'},
+		{"version", no_argument, NULL, 'V'},
+		{"help", no_argument, NULL, 'h'},
+		{NULL, 0, NULL, 0}
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+	atexit(close_stdout);
+

sys-utils/zramctl.c new file +6 -0

+			break;
+		case 'd':
+			if (dev != NULL) {
+				fprintf(stderr,_("-f || -d <name>\n"));
+				return 1;
+			}

sys-utils/zramctl.c new file +49 -1

+				usage(stderr);
+				return 1;
+			}
+			break;
+		case 'r':
+			dev = optarg;
+			if (value2devparm(dev, "1", "reset") < 0)
+				return 1;
+			break;
+		case 'V':
+			printf(UTIL_LINUX_VERSION);
+			return EXIT_SUCCESS;
+		case 'h':
+			usage(stdout);
+		default:
+			usage(stderr);
+		}
+	}
+	if (argc == 1) {
+		status();
+		return EXIT_SUCCESS;
+	}
+
+	if (!strcmp(dev, "USED")) {
+		fprintf(stderr,_("all device already used\n") );
+		return 1;
+	}
+
+	if (dev != NULL && size != NULL) {
+		if (value2devparm(dev, "1", "reset") < 0)
+			return 1;
+		if (atoi(threads) > 1)
+
+			if (value2devparm(dev, threads, "max_comp_streams") < 0)
+				return 1;
+		if (alg != NULL)
+			if (value2devparm(dev, alg, "comp_algorithm") < 0)
+				return 1;
+
+		if (value2devparm(dev, size, "disksize") < 0)
+			return 1;
+	} else {
+	}
+
+	if (dev != NULL && f > 0)
+		fprintf(stdout,_("%s\n"), dev);
+
+	return EXIT_SUCCESS;
+}
\ No newline at end of file
--

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Quoted 11 lines

Good time of day,
I spend some time and rewrite zramctl for util-linux.

Please review code and man pages, i think what i can do it better. If you have any suggestion, say it out.

Can be pulled from:
https://github.com/Nefelim4ag/util-linux

For detail see man pages zramctl.8

I have a general fear of your repeated usage of strcpy-ish functions into fixed size buffers and lack of error reporting...

I've left a few specific comments inline. I'm sure there's other things that need pointing out.

Quoted 170 lines

----

 sys-utils/Makemodule.am |   5 +
 sys-utils/zramctl.8     |  92 ++++++++++++++
 sys-utils/zramctl.c     | 319
++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 416 insertions(+)

sys-utils/Makemodule.am +5 -0

index 68fd030..5d70c51 100644
@@ -172,6 +172,11 @@ eject_CFLAGS = $(AM_CFLAGS) -I$(ul_libmount_incdir)
 dist_man_MANS += sys-utils/eject.1
 endif
 
+sbin_PROGRAMS += zramctl
+dist_man_MANS += sys-utils/zramctl.8
+zramctl_SOURCES = sys-utils/zramctl.c
+zramctl_LDADD = $(LDADD) libcommon.la libsmartcols.la
+zramctl_CFLAGS = $(AM_CFLAGS) -I$(ul_libsmartcols_incdir)
 
 if BUILD_LOSETUP
 sbin_PROGRAMS += losetup

sys-utils/zramctl.8 new file +50 -0

new file mode 100644
index 0000000..4da209d
@@ -0,0 +1,92 @@
+.TH ZRAMCTL 8 "July 2014" "util-linux" "System Administration"
+.SH NAME
+zramctl \- set up and control zram devices
+.SH SYNOPSIS
+.ad l
+Get info:
+.sp
+.in +5
+.B zramctl
+.sp
+.in -5
+Reset zram:
+.sp
+.in +5
+.B "zramctl \-r"
+.IR zramdev
+.sp
+.in -5
+Print name of first unused zram device:
+.sp
+.in +5
+.B "zramctl \-f"
+.sp
+.in -5
+Setup zram device:
+.sp
+.in +5
+.B zramctl
+.RB { \-f\ [ \-d\ \fIzramdev\fP] }
+.RB [ \-s
+.IR size ]
+.RB \ [ \-t
+.IR number ]
+.in +8
+.RB [ \-a
+.IR algorithm ]
+.sp
+.in -13
+.ad b
+.SH DESCRIPTION
+.B zramctl
+is used to fast setup zram devices parametrs, to reset zram devices and to
+query the status of a used zram devices.
+If no option is given, all zram devices are shown.
+
+
+.SH OPTIONS
+
+.IP "\fB\-s, \-\-size\fP \fIsize\fP
+force zram driver to reread size of the file associated with the specified

zram device
++The \fIsize\fR arguments may be followed by the multiplicative ++suffixes 128K 512M, 1G.
+.IP "\fB\-r, \-\-reset\fP \fIzramdev\fP"
+Reset options specified zram device(s). Zram device setting can be changed only

sys-utils/zramctl.8 new file +38 -0

+after reset.
+.IP "\fB\-f, \-\-find\fP"
+find the first unused zram device. If a
+.R \-s \fIsize\fR
+argument is present, use this device.
+.IP "\fB\-h, \-\-help\fP"
+print help
+.IP "\fB\-t, \-\-threads \fInumber\fP"
+Set number of maximum compress streams what used for device.
+.IP "\fB\-a, \-\-alg \fI{lzo|lz4}\fP""
+Set compress algorithm used for compress data in zram device.
+
+.SH RETURN VALUE
+.B zramctl
+returns 0 on success, nonzero on failure.
+
+.SH FILES
+.TP
+.I /dev/zram[0..N]
+zram block devices
+
+.SH EXAMPLE
+The following commands can be used as an example of using the zram device.
+.nf
+.IP
+# zramctl --find --size 1024M
+/dev/zram0
+# mkswap /dev/zram0
+# swapon /dev/zram0
+ ...
+# swapoff /dev/zram0
+# zramctl --reset /dev/zram0
+.fi
+.SH AUTHORS
+Timofey Titovets <[email protected]>
+.SH AVAILABILITY
+The zramctl command is part of the util-linux package and is available from
+ftp://ftp.kernel.org/pub/linux/utils/util-linux/.

sys-utils/zramctl.c new file +41 -0

new file mode 100644
index 0000000..6ddee9b
@@ -0,0 +1,319 @@
+/*
+ * zramctl - purpose of it
+ *
+ * Copyright (c) 20nn  Example Commercial, Inc
+ * Written by Timofey Titovets <[email protected]>
+ *
+ * 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.
+ *
+ * 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.  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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "c.h"
+#include "closestream.h"
+#include "nls.h"
+
+static inline int zram_exist(char *name)
+{
+     struct stat info;
+     char path[16] = "/dev/";
+     strncat(path, name, 8);
+     if(stat(path, &info) != 0 )
+             return 0;
+     if (info.st_mode&S_IFBLK)
+             return 1;

sys-utils/zramctl.c line 51

Quoted 10 lines

sys-utils/zramctl.c new file +10 -0

+     return 0;
+}
+
+static inline int read_file(char *path, char *data)
+{
+     FILE *file;
+     unsigned i = 0;
+     char ch = EOF;
+     char *p;
+     p = path; // hack for work fopen

I don't understand this comment, or code, at all. Your comment should explain as much.

Quoted 17 lines

sys-utils/zramctl.c new file +17 -0

+     file = fopen(p, "r");
+     if (file == NULL) {
+             fprintf(stderr,_("can't open !%s!\n"), path);
+             return -1;
+     }
+
+     while (1) {
+             ch = fgetc(file);
+             if (ch == EOF || ch == '\n')
+                     break;
+             else
+                     data[i]=ch;
+             i++;
+     }
+     fclose(file);
+
+     return 0;

sys-utils/zramctl.c line 78

Quoted 10 lines

sys-utils/zramctl.c new file +10 -0

+}
+
+static inline int used(char *name)
+{
+     char path_to_disksize[32] = "/sys/block/";
+     char disksize[32]="";
+     strncat(path_to_disksize, name, 8);
+     strncat(path_to_disksize, "/disksize", 9);
+     if(read_file(path_to_disksize, disksize) < 0)
+             return -1;

This seems to be poorly reimplementing things in include/sysfs.h.

Quoted 4 lines

sys-utils/zramctl.c new file +4 -0

+
+     if (disksize[0] == '0')
+             return 0;
+

sys-utils/zramctl.c line 92

Quoted 10 lines

sys-utils/zramctl.c new file +10 -0

+     return 1;
+}
+
+static inline int get_value(char *name, char *data, char *filename)
+{
+     char path[48] = "/sys/block/";
+     strncat(path, name, 8);
+     strncat(path,"/", 2);
+     strncat(path, filename, 32);
+     return read_file(path, data);

Same as above...

Quoted 5 lines

sys-utils/zramctl.c new file +5 -0

+}
+
+static inline int write_file(char *path, char *data)
+{
+     FILE *file;

sys-utils/zramctl.c line 107

Quoted 10 lines

sys-utils/zramctl.c new file +10 -0

+     char *p = path;
+     file = fopen(p, "w");
+     if (file == NULL) {
+             fprintf(stderr,_("can't write to %s\n"), path);
+             return -1;
+     }
+     fwrite(data, strlen(data), 1, file);
+     if (fclose(file) != 0)
+             return -1;
+     return 1;

If this fails, it does so silently. There's no explanation of what your synthesized return values mean.

sys-utils/zramctl.c line 117

Quoted 10 lines

sys-utils/zramctl.c new file +10 -0

+}
+
+static inline int value2devparm(char *name, char *data, char *filename)
+{
+     char path[48] = "/sys/block/";
+     strncat(path, name, 8);
+     strncat(path,"/", 2);
+     strncat(path, filename, 32);
+     return write_file(path, data);
+}

Same comment about sysfs.h

sys-utils/zramctl.c line 128

Quoted 11 lines

sys-utils/zramctl.c new file +11 -0

+
+static inline int status(void)
+{
+     char disksize[32]="";
+     char orig_data_size[32]="";
+     char compr_data_size[32]="";
+     char comp_algorithm[6]="";
+     char max_comp_streams[12]="";
+     unsigned i;
+     char *table = "%6s %12s %10s %10s %4s %4s \n";
+     printf(table, "NAME","DISKSIZE","ORIG","COMPRES","ALG","THR");

Not really extensible. You really ought to adopt the style used in utils like lsblk or findmnt to make this dynamic.

Quoted 81 lines

sys-utils/zramctl.c new file +81 -0

+     for (i=0;;i++) {
+             char name[8] = "zram";
+             char num[4];
+             char *pos;
+             sprintf(num,"%i",i);
+             strncat(name, num, 8);
+             if(!zram_exist(name))
+                     break;
+             if(!used(name))
+                     continue;
+             get_value(name, disksize, "disksize");
+             get_value(name, orig_data_size, "orig_data_size");
+             get_value(name, compr_data_size, "compr_data_size");
+             get_value(name, comp_algorithm, "comp_algorithm");
+             pos = strstr(comp_algorithm, "[lzo]");
+             if (pos == NULL) {
+                     pos = strstr(comp_algorithm, "[lz4]");
+                     if (pos == NULL)
+                             strncpy(comp_algorithm,"-", 2);
+                     else
+                             strncpy(comp_algorithm, "lz4", 4);
+             } else
+                     strncpy(comp_algorithm, "lzo", 4);
+             get_value(name, max_comp_streams, "max_comp_streams");
+             printf(table,
+                     name,
+                     disksize,
+                     orig_data_size,
+                     compr_data_size,
+                     comp_algorithm,
+                     max_comp_streams
+                   );
+     }
+
+     return 0;
+     goto fail;
+fail:
+     printf("Zram module not loaded");
+     return -1;
+}
+
+static inline char *find(void)
+{
+     char *ret = NULL;
+     for (unsigned i=0;;i++) {
+             char name[8] = "zram";
+             char num[4];
+
+             sprintf(num,"%i",i);
+             strncat(name, num, 4);
+             if (!zram_exist(name))
+                     break;
+             else    //if enough one dir founded -> module loaded
+                     ret = "USED";
+
+             if (used(name) == 0) {
+                     ret = name;
+                     break;
+             }
+     }
+
+             return ret;
+}
+
+
+
+static inline void usage(FILE *out)
+{
+     fputs(USAGE_HEADER, out);
+     fprintf(out, _(" %s [-d zramX|-f] -s 64M -a lz4 -t 16\n"), "zramctl");
+     fputs(USAGE_OPTIONS, out);
+     fputs(_(" <no args>             return status of used devices\n"), out);
+     fputs(_(" -f, --find            find free device\n"), out);
+     fputs(_(" -d, --device [name]   specify device: zramX\n"), out);
+     fputs(_(" -r, --reset  [name]   reset specified device\n"), out);
+     fputs(_(" -s, --size [size]     device size: 131072, 1024M...\n"), out);
+     fputs(_(" -a, --alg [lzo|lz4]   compress algorithm\n"), out);
+     fputs(_(" -t, --threads [0<num] number of compress streams\n"), out);
+     fputs(USAGE_SEPARATOR, out);
+     fputs(USAGE_HELP, out);
+     fputs(USAGE_VERSION, out);

sys-utils/zramctl.c line 219

Quoted 10 lines

sys-utils/zramctl.c new file +10 -0

+     fprintf(out, USAGE_MAN_TAIL("zramctl(8)"));
+     exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int main(int argc, char **argv)
+{
+     int c = 0;
+     char *dev = NULL;
+     char *size = NULL;
+     char *alg = NULL;

These variable names are pretty nondescript. alg? what is that? a search algorithm? red algae? size? size of what?

Quoted 20 lines

sys-utils/zramctl.c new file +20 -0

+     char threads[5] = "1";
+     unsigned f = 0;
+
+     static const struct option longopts[] = {
+             {"find", no_argument, NULL, 'f'},
+             {"device", required_argument, NULL, 'd'},
+             {"size", required_argument, NULL, 's'},
+             {"alg", required_argument, NULL, 'a'},
+             {"threads", required_argument, NULL, 't'},
+             {"reset", required_argument, NULL, 'r'},
+             {"version", no_argument, NULL, 'V'},
+             {"help", no_argument, NULL, 'h'},
+             {NULL, 0, NULL, 0}
+     };
+
+     setlocale(LC_ALL, "");
+     bindtextdomain(PACKAGE, LOCALEDIR);
+     textdomain(PACKAGE);
+     atexit(close_stdout);
+

sys-utils/zramctl.c line 248

Quoted 10 lines

sys-utils/zramctl.c new file +9 -1

+     while ((c = getopt_long(argc, argv, "fd:s:a:t:r:Vh", longopts, NULL)) !=
-1) {
+             switch (c) {
+             case 'f':
+                     if (dev != NULL) {
+                             fprintf(stderr,_("-f || -d <name>\n"));
+                             return 1;
+                     }
+                     f = 1;
+                     dev = find();

find *what*? The name of this function should be descriptive enough to tell you that.

Quoted 6 lines

sys-utils/zramctl.c new file +6 -0

+                     break;
+             case 'd':
+                     if (dev != NULL) {
+                             fprintf(stderr,_("-f || -d <name>\n"));
+                             return 1;
+                     }

sys-utils/zramctl.c line 264

Quoted 10 lines

sys-utils/zramctl.c new file +10 -0

+                     dev = optarg;
+                     break;
+             case 's':
+                     size = optarg;
+                     break;
+             case 'a':
+                     if (!strcmp(optarg,"lzo") || !strcmp(optarg,"lz4"))
+                             alg = optarg;
+                     else {
+                             fprintf(stderr,_("%s != lzo|lz4\n"),alg );

How would this string be localized? LZO is LZO is LZO, regardless of what language you're speaking.

sys-utils/zramctl.c line 269

Quoted 5 lines

sys-utils/zramctl.c new file +5 -0

+                             return 1;
+                     }
+                     break;
+             case 't':
+                     strncpy(threads, optarg, 5);

Why do you need to copy this? More importantly, if someone passes '100000', you'll be left with { '1', '0', '0', '0', '0' } in your array (no zero byte termination!)

Quoted 1 line

+ if (atoi(threads) < 1) {

Poor UX here -- you're erroring out and dumping a wall of text without explaining why.

Quoted 54 lines

sys-utils/zramctl.c new file +49 -1

+                             usage(stderr);
+                             return 1;
+                     }
+                     break;
+             case 'r':
+                     dev = optarg;
+                     if (value2devparm(dev, "1", "reset") < 0)
+                             return 1;
+                     break;
+             case 'V':
+                     printf(UTIL_LINUX_VERSION);
+                     return EXIT_SUCCESS;
+             case 'h':
+                     usage(stdout);
+             default:
+                     usage(stderr);
+             }
+     }
+     if (argc == 1) {
+             status();
+             return EXIT_SUCCESS;
+     }
+
+     if (!strcmp(dev, "USED")) {
+             fprintf(stderr,_("all device already used\n") );
+             return 1;
+     }
+
+     if (dev != NULL && size != NULL) {
+             if (value2devparm(dev, "1", "reset") < 0)
+                     return 1;
+             if (atoi(threads) > 1)
+
+                     if (value2devparm(dev, threads, "max_comp_streams") < 0)
+                             return 1;
+             if (alg != NULL)
+                     if (value2devparm(dev, alg, "comp_algorithm") < 0)
+                             return 1;
+
+             if (value2devparm(dev, size, "disksize") < 0)
+                     return 1;
+     } else {
+     }
+
+     if (dev != NULL && f > 0)
+             fprintf(stdout,_("%s\n"), dev);
+
+     return EXIT_SUCCESS;
+}
\ No newline at end of file
--

To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

sys-utils/zramctl.c line 128

Quoted 2 lines

sys-utils/zramctl.c new file +2 -0

+	char *table = "%6s %12s %10s %10s %4s %4s \n";
+	printf(table, "NAME","DISKSIZE","ORIG","COMPRES","ALG","THR");

Not really extensible. You really ought to adopt the style used in utils like lsblk or findmnt to make this dynamic.

Good time of day,
I spend some time and rewrite zramctl for util-linux.

Please review code and man pages, i think what i can do it better. If you have any suggestion, say it out.

Can be pulled from:
https://github.com/Nefelim4ag/util-linux

For detail see man pages zramctl.8

----

 sys-utils/Makemodule.am |   5 +
 sys-utils/zramctl.8     |  92 ++++++++++++++
 sys-utils/zramctl.c     | 319
++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 416 insertions(+)

sys-utils/Makemodule.am +5 -0

index 68fd030..5d70c51 100644
@@ -172,6 +172,11 @@ eject_CFLAGS = $(AM_CFLAGS) -I$(ul_libmount_incdir)
 dist_man_MANS += sys-utils/eject.1
 endif
 
+sbin_PROGRAMS += zramctl
+dist_man_MANS += sys-utils/zramctl.8
+zramctl_SOURCES = sys-utils/zramctl.c
+zramctl_LDADD = $(LDADD) libcommon.la libsmartcols.la
+zramctl_CFLAGS = $(AM_CFLAGS) -I$(ul_libsmartcols_incdir)
 
 if BUILD_LOSETUP
 sbin_PROGRAMS += losetup

sys-utils/zramctl.8 new file +50 -0

new file mode 100644
index 0000000..4da209d
@@ -0,0 +1,92 @@
+.TH ZRAMCTL 8 "July 2014" "util-linux" "System Administration"
+.SH NAME
+zramctl \- set up and control zram devices
+.SH SYNOPSIS
+.ad l
+Get info:
+.sp
+.in +5
+.B zramctl
+.sp
+.in -5
+Reset zram:
+.sp
+.in +5
+.B "zramctl \-r"
+.IR zramdev
+.sp
+.in -5
+Print name of first unused zram device:
+.sp
+.in +5
+.B "zramctl \-f"
+.sp
+.in -5
+Setup zram device:
+.sp
+.in +5
+.B zramctl
+.RB { \-f\ [ \-d\ \fIzramdev\fP] }
+.RB [ \-s
+.IR size ]
+.RB \ [ \-t
+.IR number ]
+.in +8
+.RB [ \-a
+.IR algorithm ]
+.sp
+.in -13
+.ad b
+.SH DESCRIPTION
+.B zramctl
+is used to fast setup zram devices parametrs, to reset zram devices and to
+query the status of a used zram devices.
+If no option is given, all zram devices are shown.
+
+
+.SH OPTIONS
+
+.IP "\fB\-s, \-\-size\fP \fIsize\fP
+force zram driver to reread size of the file associated with the specified

zram device
++The \fIsize\fR arguments may be followed by the multiplicative ++suffixes 128K 512M, 1G.
+.IP "\fB\-r, \-\-reset\fP \fIzramdev\fP"
+Reset options specified zram device(s). Zram device setting can be changed only

sys-utils/zramctl.8 new file +38 -0

+after reset.
+.IP "\fB\-f, \-\-find\fP"
+find the first unused zram device. If a
+.R \-s \fIsize\fR
+argument is present, use this device.
+.IP "\fB\-h, \-\-help\fP"
+print help
+.IP "\fB\-t, \-\-threads \fInumber\fP"
+Set number of maximum compress streams what used for device.
+.IP "\fB\-a, \-\-alg \fI{lzo|lz4}\fP""
+Set compress algorithm used for compress data in zram device.
+
+.SH RETURN VALUE
+.B zramctl
+returns 0 on success, nonzero on failure.
+
+.SH FILES
+.TP
+.I /dev/zram[0..N]
+zram block devices
+
+.SH EXAMPLE
+The following commands can be used as an example of using the zram device.
+.nf
+.IP
+# zramctl --find --size 1024M
+/dev/zram0
+# mkswap /dev/zram0
+# swapon /dev/zram0
+ ...
+# swapoff /dev/zram0
+# zramctl --reset /dev/zram0
+.fi
+.SH AUTHORS
+Timofey Titovets <[email protected]>
+.SH AVAILABILITY
+The zramctl command is part of the util-linux package and is available from
+ftp://ftp.kernel.org/pub/linux/utils/util-linux/.

sys-utils/zramctl.c new file +237 -0

new file mode 100644
index 0000000..6ddee9b
@@ -0,0 +1,319 @@
+/*
+ * zramctl - purpose of it
+ *
+ * Copyright (c) 20nn  Example Commercial, Inc
+ * Written by Timofey Titovets <[email protected]>
+ *
+ * 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.
+ *
+ * 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.  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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "c.h"
+#include "closestream.h"
+#include "nls.h"
+
+static inline int zram_exist(char *name)
+{
+	struct stat info;
+	char path[16] = "/dev/";
+	strncat(path, name, 8);
+	if(stat(path, &info) != 0 )
+		return 0;
+	if (info.st_mode&S_IFBLK)
+		return 1;
+	return 0;
+}
+
+static inline int read_file(char *path, char *data)
+{
+	FILE *file;
+	unsigned i = 0;
+	char ch = EOF;
+	char *p;
+	p = path; // hack for work fopen
+	file = fopen(p, "r");
+	if (file == NULL) {
+		fprintf(stderr,_("can't open !%s!\n"), path);
+		return -1;
+	}
+
+	while (1) {
+		ch = fgetc(file);
+		if (ch == EOF || ch == '\n')
+			break;
+		else
+			data[i]=ch;
+		i++;
+	}
+	fclose(file);
+
+	return 0;
+}
+
+static inline int used(char *name)
+{
+	char path_to_disksize[32] = "/sys/block/";
+	char disksize[32]="";
+	strncat(path_to_disksize, name, 8);
+	strncat(path_to_disksize, "/disksize", 9);
+	if(read_file(path_to_disksize, disksize) < 0)
+		return -1;
+
+	if (disksize[0] == '0')
+		return 0;
+
+	return 1;
+}
+
+static inline int get_value(char *name, char *data, char *filename)
+{
+	char path[48] = "/sys/block/";
+	strncat(path, name, 8);
+	strncat(path,"/", 2);
+	strncat(path, filename, 32);
+	return read_file(path, data);
+}
+
+static inline int write_file(char *path, char *data)
+{
+	FILE *file;
+	char *p = path;
+	file = fopen(p, "w");
+	if (file == NULL) {
+		fprintf(stderr,_("can't write to %s\n"), path);
+		return -1;
+	}
+	fwrite(data, strlen(data), 1, file);
+	if (fclose(file) != 0)
+		return -1;
+	return 1;
+}
+
+static inline int value2devparm(char *name, char *data, char *filename)
+{
+	char path[48] = "/sys/block/";
+	strncat(path, name, 8);
+	strncat(path,"/", 2);
+	strncat(path, filename, 32);
+	return write_file(path, data);
+}
+
+static inline int status(void)
+{
+	char disksize[32]="";
+	char orig_data_size[32]="";
+	char compr_data_size[32]="";
+	char comp_algorithm[6]="";
+	char max_comp_streams[12]="";
+	unsigned i;
+	char *table = "%6s %12s %10s %10s %4s %4s \n";
+	printf(table, "NAME","DISKSIZE","ORIG","COMPRES","ALG","THR");
+	for (i=0;;i++) {
+		char name[8] = "zram";
+		char num[4];
+		char *pos;
+		sprintf(num,"%i",i);
+		strncat(name, num, 8);
+		if(!zram_exist(name))
+			break;
+		if(!used(name))
+			continue;
+		get_value(name, disksize, "disksize");
+		get_value(name, orig_data_size, "orig_data_size");
+		get_value(name, compr_data_size, "compr_data_size");
+		get_value(name, comp_algorithm, "comp_algorithm");
+		pos = strstr(comp_algorithm, "[lzo]");
+		if (pos == NULL) {
+			pos = strstr(comp_algorithm, "[lz4]");
+			if (pos == NULL)
+				strncpy(comp_algorithm,"-", 2);
+			else
+				strncpy(comp_algorithm, "lz4", 4);
+		} else
+			strncpy(comp_algorithm, "lzo", 4);
+		get_value(name, max_comp_streams, "max_comp_streams");
+		printf(table,
+			name,
+			disksize,
+			orig_data_size,
+			compr_data_size,
+			comp_algorithm,
+			max_comp_streams
+		      );
+	}
+
+	return 0;
+	goto fail;
+fail:
+	printf("Zram module not loaded");
+	return -1;
+}
+
+static inline char *find(void)
+{
+	char *ret = NULL;
+	for (unsigned i=0;;i++) {
+		char name[8] = "zram";
+		char num[4];
+
+		sprintf(num,"%i",i);
+		strncat(name, num, 4);
+		if (!zram_exist(name))
+			break;
+		else	//if enough one dir founded -> module loaded
+			ret = "USED";
+
+		if (used(name) == 0) {
+			ret = name;
+			break;
+		}
+	}
+
+		return ret;
+}
+
+
+
+static inline void usage(FILE *out)
+{
+	fputs(USAGE_HEADER, out);
+	fprintf(out, _(" %s [-d zramX|-f] -s 64M -a lz4 -t 16\n"), "zramctl");
+	fputs(USAGE_OPTIONS, out);
+	fputs(_(" <no args>             return status of used devices\n"), out);
+	fputs(_(" -f, --find            find free device\n"), out);
+	fputs(_(" -d, --device [name]   specify device: zramX\n"), out);
+	fputs(_(" -r, --reset  [name]   reset specified device\n"), out);
+	fputs(_(" -s, --size [size]     device size: 131072, 1024M...\n"), out);
+	fputs(_(" -a, --alg [lzo|lz4]   compress algorithm\n"), out);
+	fputs(_(" -t, --threads [0<num] number of compress streams\n"), out);
+	fputs(USAGE_SEPARATOR, out);
+	fputs(USAGE_HELP, out);
+	fputs(USAGE_VERSION, out);
+	fprintf(out, USAGE_MAN_TAIL("zramctl(8)"));
+	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int main(int argc, char **argv)
+{
+	int c = 0;
+	char *dev = NULL;
+	char *size = NULL;
+	char *alg = NULL;
+	char threads[5] = "1";
+	unsigned f = 0;
+
+	static const struct option longopts[] = {
+		{"find", no_argument, NULL, 'f'},
+		{"device", required_argument, NULL, 'd'},
+		{"size", required_argument, NULL, 's'},
+		{"alg", required_argument, NULL, 'a'},
+		{"threads", required_argument, NULL, 't'},
+		{"reset", required_argument, NULL, 'r'},
+		{"version", no_argument, NULL, 'V'},
+		{"help", no_argument, NULL, 'h'},
+		{NULL, 0, NULL, 0}
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);

sys-utils/zramctl.c new file +14 -0

+			f = 1;
+			dev = find();
+			break;
+		case 'd':
+			if (dev != NULL) {
+				fprintf(stderr,_("-f || -d <name>\n"));
+				return 1;
+			}
+			dev = optarg;
+			break;
+		case 's':
+			size = optarg;
+			break;
+		case 'a':

+.B zramctl
+.RB { \-f\ [ \-d\ \fIzramdev\fP] }

+.IP "\fB\-s, \-\-size\fP \fIsize\fP
+force zram driver to reread size of the file associated with the specified zram device

++The \fIsize\fR arguments may be followed by the multiplicative ++suffixes 128K 512M, 1G.

+.IP "\fB\-h, \-\-help\fP"
+print help

+.SH EXAMPLE
+The following commands can be used as an example of using the zram device.

+ * Copyright (c) 20nn Example Commercial, Inc
+ * Written by Timofey Titovets <[email protected]>

I spend some time and rewrite zramctl for util-linux.

sysfs.h powerful, but i can't understand how working sysfs.h and how i can implement it(?), and i think what my helper function is easier now, than sysfs.h realization

Quoted 1 line

I spend some time and rewrite zramctl for util-linux.

Thanks! Merged.

Quoted 3 lines

sysfs.h powerful, but i can't understand how working sysfs.h and how i can implement it(?), and i think what my helper function is easier now, than sysfs.h realization

I have modified your code to use sysfs stuff and to use libsmartcols in better way. So now it's more compatible with another ls-like utils we have in util-linux. For example you can specify output columns by --output, it makes it more friendly for scripts etc.

 # /zramctl
 NAME       ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT
 /dev/zram1               100M  44K  876B   44K         /mnt/test
 /dev/zram2               123M   4K   78B    4K         [SWAP]
 /dev/zram3                10M   0B    0B    0B

Note that I have kernel 3.14, so things like number of compression streams and compression algorithm are invisible for me (I going to update and test it with new kernel this afternoon).

Anyway, zRam seems like nice project. I'll try to add support to swapon next week. My idea is something like (in fstab):

/dev/zram0 swap swap x-zram.disksize=100M,x-zram.algorithm=lzo,auto

it means use x-* options (we use this notation for another things) to specify zram setting. The controversial thing is that we have to call mkswap from swapon, but it's already supported for swap reinitialization (after system resume or on page size change etc.)

... or is it over-engineering?

Karel

--
Karel Zak <[email protected]>
http://karelzak.blogspot.com