fstrim: add new command

fstrim is used on a mounted filesystem to discard (or "trim") blocks
which are not in use by the filesystem.  This is useful for
solid-state drives (SSDs) and thinly-provisioned storage

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 154 insertions, 0 deletions

diff --git a/sys-utils/fstrim.c b/sys-utils/fstrim.c
new file mode 100644
index 000000000..fd83d3111
--- /dev/null
+++ b/sys-utils/fstrim.c
@@ -0,0 +1,154 @@
+/*
+ * fstrim.c -- discard the part (or whole) of mounted filesystem.
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All rights reserved.
+ * Written by Lukas Czerner <lczerner@redhat.com>
+ *            Karel Zak <kzak@redhat.com>
+ *
+ * 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/>.
+ *
+ *
+ * This program uses FITRIM ioctl to discard parts or the whole filesystem
+ * online (mounted). You can specify range (start and length) to be
+ * discarded, or simply discard while filesystem.
+ */
+
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <getopt.h>
+#include <err.h>
+#include <error.h>
+#include <errno.h>
+
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <linux/fs.h>
+
+#include "nls.h"
+#include "strutils.h"
+
+#ifndef FITRIM
+struct fstrim_range {
+	uint64_t start;
+	uint64_t len;
+	uint64_t minlen;
+};
+#define FITRIM		_IOWR('X', 121, struct fstrim_range)
+#endif
+
+static void __attribute__((__noreturn__)) usage(FILE *out)
+{
+	fprintf(out, _("Usage: %s [options] <mount point>\n\nOptions:\n"),
+			program_invocation_short_name);
+
+	fprintf(out, _(
+		" -h, --help          this help\n"
+		" -o, --offset <num>  offset in bytes to discard from\n"
+		" -l, --length <num>  length of bytes to discard from the offset\n"
+		" -m, --minimum <num> minimum extent length to discard\n"
+		" -v, --verbose       print number of discarded bytes\n"));
+
+	fprintf(out, _("\nFor more information see fstrim(1).\n"));
+
+	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int main(int argc, char **argv)
+{
+	char *path;
+	int c, fd, verbose = 0;
+	struct fstrim_range range;
+	struct stat sb;
+
+	struct option longopts[] = {
+	    { "help",      0, 0, 'h' },
+	    { "offset",    1, 0, 'o' },
+	    { "length",    1, 0, 'l' },
+	    { "minimum",   1, 0, 'm' },
+	    { "verbose",   0, 0, 'v' },
+	    { NULL,        0, 0, 0 }
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+
+	memset(&range, 0, sizeof(range));
+	range.len = ULLONG_MAX;
+
+	while ((c = getopt_long(argc, argv, "ho:l:m:v", longopts, NULL)) != -1) {
+		switch(c) {
+		case 'h':
+			usage(stdout);
+			break;
+		case 'l':
+			if (strtosize(optarg, &range.len))
+				errx(EXIT_FAILURE,
+				     _("failed to parse length: %s"), optarg);
+			break;
+		case 'o':
+			if (strtosize(optarg, &range.start))
+				errx(EXIT_FAILURE,
+				     _("failed to parse offset: %s"), optarg);
+			break;
+		case 'm':
+			if (strtosize(optarg, &range.minlen))
+				errx(EXIT_FAILURE,
+				     _("failed to parse minimal extend length: %s"),
+				     optarg);
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		default:
+			usage(stderr);
+			break;
+		}
+	}
+
+	if (optind == argc)
+		errx(EXIT_FAILURE, _("no mountpoint specified."));
+
+	path = argv[optind++];
+
+	if (optind != argc) {
+		warnx(_("unexpected number of arguments"));
+		usage(stderr);
+	}
+
+	if (stat(path, &sb) == -1)
+		err(EXIT_FAILURE, _("%s: stat failed"), path);
+	if (!S_ISDIR(sb.st_mode))
+		errx(EXIT_FAILURE, _("%s: not a directory"), path);
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		err(EXIT_FAILURE, _("%s: open failed"), path);
+
+	if (ioctl(fd, FITRIM, &range)) {
+		int errsv = errno;
+		close(fd);
+		error(EXIT_FAILURE, errsv, _("%s: FITRIM ioctl failed"), path);
+	}
+	if (verbose)
+		printf(_("%s: %" PRIu64 " bytes was trimmed\n"),
+						path, range.len);
+	close(fd);
+	return EXIT_SUCCESS;
+}