linux-ext4 - [PATCH] mke2fs: Inform user about ongoing discard

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1287670982-32348-1-git-send-email-lczerner@redhat.com>
Date:	Thu, 21 Oct 2010 16:23:02 +0200
From:	Lukas Czerner <lczerner@...hat.com>
To:	linux-ext4@...r.kernel.org
Cc:	tytso@....edu, sandeen@...hat.com, adilger@...ger.ca,
	lczerner@...hat.com
Subject: [PATCH] mke2fs: Inform user about ongoing discard

Since there are some slow SSD's out there and big thinly provisioned
storages on which it takes quite long to issue discard through whole
device, it would be nice to provide user the information about what is
going on and how long it will take (approximately).

Signed-off-by: Lukas Czerner <lczerner@...hat.com>
---
 misc/mke2fs.c |   56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 56 insertions(+), 0 deletions(-)

diff --git a/misc/mke2fs.c b/misc/mke2fs.c
index 0980045..560df31 100644
--- a/misc/mke2fs.c
+++ b/misc/mke2fs.c
@@ -1907,6 +1907,56 @@ static int mke2fs_setup_tdb(const char *name, io_manager *io_ptr)
 #define BLKDISCARDZEROES _IO(0x12,124)
 #endif
 
+
+/* On how big chunk of disk do we test discard (in percentage) */
+#define DISCARD_TEST_RANGE_PERC		1
+#define DISCARD_TEST_RANGE(x, y)	\
+	((((x) / 100) *			\
+	DISCARD_TEST_RANGE_PERC +	\
+	(y)-1 / (y)) * (y))
+#define DISCARD_TEST_COUNT		5
+
+static int check_discard_support(int fd, int blocksize, __u64 blocks,
+				 double *time)
+{
+	int ret = 0, i;
+	double tmp_time = 0;
+	__uint64_t range[2];
+	struct timeval tv_start, tv_stop;
+
+	range[0] = 0;
+	range[1] = DISCARD_TEST_RANGE(blocks, blocksize);
+
+	for (i = 0; i < DISCARD_TEST_COUNT; i++) {
+
+		if (gettimeofday(&tv_start, (struct timezone *) NULL) == -1)
+			perror("gettimeofday");
+
+		ret = ioctl(fd, BLKDISCARD, &range);
+		if (ret)
+			return ret;
+
+		if (gettimeofday(&tv_stop, (struct timezone *) NULL) == -1) {
+			perror("gettimeofday");
+			return ret;
+		}
+
+		if (0 == i)
+			printf(_("Discarding all blocks on device "));
+
+		/* time diff */
+		tmp_time += ((double) tv_stop.tv_sec +
+			(((double) tv_stop.tv_usec) * 0.000001)) -
+			((double) tv_start.tv_sec +
+			(((double) tv_start.tv_usec) * 0.000001));
+	}
+
+	*time = (tmp_time / DISCARD_TEST_COUNT) *
+		(100 / DISCARD_TEST_RANGE_PERC);
+
+	return ret;
+}
+
 /*
  * Return zero if the discard succeeds, and -1 if the discard fails.
  */
@@ -1917,6 +1967,7 @@ static int mke2fs_discard_blocks(ext2_filsys fs)
 	int blocksize;
 	__u64 blocks;
 	__uint64_t range[2];
+	double time = 0;
 
 	blocks = ext2fs_blocks_count(fs->super);
 	blocksize = EXT2_BLOCK_SIZE(fs->super);
@@ -1926,6 +1977,11 @@ static int mke2fs_discard_blocks(ext2_filsys fs)
 	fd = open64(fs->device_name, O_RDWR);
 
 	if (fd > 0) {
+		ret = check_discard_support(fd, blocksize, blocks, &time);
+		if (ret)
+			return;
+		printf(_("(Estimated time: %.2lfs).\n"), time);
+
 		ret = ioctl(fd, BLKDISCARD, &range);
 		if (verbose) {
 			printf(_("Calling BLKDISCARD from %llu to %llu "),
-- 
1.7.2.3

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html