From 7154cc892688f3c58cbbcdc2055f2635c1d0ef5b Mon Sep 17 00:00:00 2001
From: Karel Zak
Date: Wed, 24 Feb 2016 15:21:38 +0100
Subject: blkdiscard: add --zeroout (BLKZEROOUT ioctl)

Requested-by: Yaniv Kaul <ykaul@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 sys-utils/blkdiscard.c | 59 ++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 47 insertions(+), 12 deletions(-)

(limited to 'sys-utils/blkdiscard.c')

diff --git a/sys-utils/blkdiscard.c b/sys-utils/blkdiscard.c
index f36e50492..ff2cee355 100644
--- a/sys-utils/blkdiscard.c
+++ b/sys-utils/blkdiscard.c
@@ -45,16 +45,37 @@
 #include "monotonic.h"
 
 #ifndef BLKDISCARD
-#define BLKDISCARD	_IO(0x12,119)
+# define BLKDISCARD	_IO(0x12,119)
 #endif
 
 #ifndef BLKSECDISCARD
-#define BLKSECDISCARD	_IO(0x12,125)
+# define BLKSECDISCARD	_IO(0x12,125)
 #endif
 
-#define print_stats(path, stats) \
-	printf(_("%s: Discarded %" PRIu64 " bytes from the " \
-		 "offset %" PRIu64"\n"), path, stats[1], stats[0]);
+#ifndef BLKZEROOUT
+# define BLKZEROOUT	_IO(0x12,127)
+#endif
+
+enum {
+	ACT_DISCARD = 0,	/* default */
+	ACT_ZEROOUT,
+	ACT_SECURE
+};
+
+static void print_stats(int act, char *path, uint64_t stats[])
+{
+	switch (act) {
+	case ACT_ZEROOUT:
+		printf(_("%s: Zero-filled %" PRIu64 " bytes from the offset %" PRIu64"\n"), \
+			path, stats[1], stats[0]);
+		break;
+	case ACT_SECURE:
+	case ACT_DISCARD:
+		printf(_("%s: Discarded %" PRIu64 " bytes from the offset %" PRIu64"\n"), \
+			path, stats[1], stats[0]);
+		break;
+	}
+}
 
 static void __attribute__((__noreturn__)) usage(FILE *out)
 {
@@ -70,6 +91,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 		" -l, --length <num>  length of bytes to discard from the offset\n"
 		" -p, --step <num>    size of the discard iterations within the offset\n"
 		" -s, --secure        perform secure discard\n"
+		" -z, --zeroout       zero-fill rather than discard\n"
 		" -v, --verbose       print aligned length and offset\n"),
 		out);
 	fputs(USAGE_SEPARATOR, out);
@@ -79,13 +101,15 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 }
 
+
 int main(int argc, char **argv)
 {
 	char *path;
-	int c, fd, verbose = 0, secure = 0, secsize;
+	int c, fd, verbose = 0, secsize;
 	uint64_t end, blksize, step, range[2], stats[2];
 	struct stat sb;
 	struct timeval now, last;
+	int act = ACT_DISCARD;
 
 	static const struct option longopts[] = {
 	    { "help",      0, 0, 'h' },
@@ -95,6 +119,7 @@ int main(int argc, char **argv)
 	    { "step",      1, 0, 'p' },
 	    { "secure",    0, 0, 's' },
 	    { "verbose",   0, 0, 'v' },
+	    { "zeroout",   0, 0, 'z' },
 	    { NULL,        0, 0, 0 }
 	};
 
@@ -107,7 +132,7 @@ int main(int argc, char **argv)
 	range[1] = ULLONG_MAX;
 	step = 0;
 
-	while ((c = getopt_long(argc, argv, "hVsvo:l:p:", longopts, NULL)) != -1) {
+	while ((c = getopt_long(argc, argv, "hVsvo:l:p:z", longopts, NULL)) != -1) {
 		switch(c) {
 		case 'h':
 			usage(stdout);
@@ -128,11 +153,14 @@ int main(int argc, char **argv)
 					_("failed to parse step"));
 			break;
 		case 's':
-			secure = 1;
+			act = ACT_SECURE;
 			break;
 		case 'v':
 			verbose = 1;
 			break;
+		case 'z':
+			act = ACT_ZEROOUT;
+			break;
 		default:
 			usage(stderr);
 			break;
@@ -189,12 +217,19 @@ int main(int argc, char **argv)
 		if (range[0] + range[1] > end)
 			range[1] = end - range[0];
 
-		if (secure) {
+		switch (act) {
+		case ACT_ZEROOUT:
+			if (ioctl(fd, BLKZEROOUT, &range))
+				 err(EXIT_FAILURE, _("%s: BLKZEROOUT ioctl failed"), path);
+			break;
+		case ACT_SECURE:
 			if (ioctl(fd, BLKSECDISCARD, &range))
 				err(EXIT_FAILURE, _("%s: BLKSECDISCARD ioctl failed"), path);
-		} else {
+			break;
+		case ACT_DISCARD:
 			if (ioctl(fd, BLKDISCARD, &range))
 				err(EXIT_FAILURE, _("%s: BLKDISCARD ioctl failed"), path);
+			break;
 		}
 
 		stats[1] += range[1];
@@ -204,7 +239,7 @@ int main(int argc, char **argv)
 			gettime_monotonic(&now);
 			if (now.tv_sec > last.tv_sec &&
 			    (now.tv_usec >= last.tv_usec || now.tv_sec > last.tv_sec + 1)) {
-				print_stats(path, stats);
+				print_stats(act, path, stats);
 				stats[0] += stats[1], stats[1] = 0;
 				last = now;
 			}
@@ -212,7 +247,7 @@ int main(int argc, char **argv)
 	}
 
 	if (verbose && stats[1])
-		print_stats(path, stats);
+		print_stats(act, path, stats);
 
 	close(fd);
 	return EXIT_SUCCESS;
-- 
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