blkzone: Add --count option

The length option is used to specify the number of zones to
operate on. To be more consistent with other tools, have this
option use a number of sectors and introduce the --count option
to allow users to specify a number of zones.
The --count and --length options cannot be used together on
the command line.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>

2 files changed, 76 insertions, 39 deletions

diff --git a/sys-utils/blkzone.8 b/sys-utils/blkzone.8
index 24b0cc7bd..983b04411 100644
--- a/sys-utils/blkzone.8
+++ b/sys-utils/blkzone.8
@@ -10,7 +10,7 @@ blkzone \- run zone command on a device
 .B blkzone
 is used to run zone command on device that support the Zoned Block Commands
 (ZBC) or Zoned-device ATA Commands (ZAC). The zones to operate on can be
-specified using the offset and length options.
+specified using the offset, count and length options.
 .PP
 The
 .I device
@@ -19,8 +19,8 @@ argument is the pathname of the block device.
 .SS report
 The command \fBblkzone report\fP is used to report device zone information.
 .PP
-By default, the command will report on up to 4k zones from the start of the
-block device.  Options may be used to modify this behavior, changing the
+By default, the command will report all zones from the start of the
+block device. Options may be used to modify this behavior, changing the
 starting zone or the size of the report, as explained below.
 
 .B Report output
@@ -52,34 +52,43 @@ x?:Reserved conditions (should not be reported)
 .TE
 
 .SS reset
-The command \fBblkzone reset\fP is used to reset one or more zones.  Unlike
-.BR sg_reset_wp (8) ,
+The command \fBblkzone reset\fP is used to reset one or more zones. Unlike
+.BR sg_reset_wp (8),
 this command operates from the block layer and can reset a range of zones.
 .PP
-By default, the command will operate from the zone at device logical
+By default, the command will operate from the zone at device 
 sector 0 and reset all zones. Options may be used to modify this behavior
 as well as specify the operation to be performed on the zone, as explained below.
-.PP
-The default number of zones (option \fB\-\-length\fP) is all zones.
 
 .SH OPTIONS
 The
 .I offset
-option argument may be followed by the multiplicative suffixes KiB (=1024),
+and
+.I length
+option arguments may be followed by the multiplicative suffixes KiB (=1024),
 MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is
 optional, e.g., "K" has the same meaning as "KiB") or the suffixes
 KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB.
-Additionally, the 0x prefix can be used to specify \fIoffset\fR in hex.
+Additionally, the 0x prefix can be used to specify \fIoffset\fR and
+\fIlength\fR in hex.
 .TP
 .BR \-o , " \-\-offset "\fIsector\fP
-The starting zone specified as a sector offset.  The provided offset in sector
-units (512 bytes) should match the start of a zone.  The default value is zero.
+The starting zone specified as a sector offset. The provided offset in sector
+units (512 bytes) should match the start of a zone. The default value is zero.
+.TP
+.BR \-l , " \-\-length "\fIsectors\fP
+The maximum number of sectors the command should operate on. The default value
+is the number of sectors remaining after \fIoffset\fR. This option cannot be
+used together with the option \fB\-\-count\fP.
 .TP
-.BR \-l , " \-\-length "\fIcount\fP
-The maximum number of zones to be used for the command.
+.BR \-l , " \-\-count "\fIcount\fP
+The maximum number of zones the command should operate on. The default value
+is the nuber of zones starting from \fIoffset\fR. This option cannot be
+used together with the option \fB\-\-length\fP.
 .TP
 .BR \-v , " \-\-verbose"
-Display the number of zones returned in the report.
+Display the number of zones returned in the report or the range of sectors
+reset..
 .TP
 .BR \-V , " \-\-version"
 Display version information and exit.
diff --git a/sys-utils/blkzone.c b/sys-utils/blkzone.c
index 2d6a76015..b9f1ed752 100644
--- a/sys-utils/blkzone.c
+++ b/sys-utils/blkzone.c
@@ -63,6 +63,7 @@ struct blkzone_control {
 
 	uint64_t offset;
 	uint64_t length;
+	uint32_t count;
 
 	unsigned int verbose : 1;
 };
@@ -137,7 +138,7 @@ static unsigned long blkdev_chunk_sectors(const char *dname)
 /*
  * blkzone report
  */
-#define DEF_REPORT_LEN		(1 << 12) /* 4k zones per report (256k kzalloc) */
+#define DEF_REPORT_LEN		(1U << 12) /* 4k zones per report (256k kzalloc) */
 
 static const char *type_text[] = {
 	"RESERVED",
@@ -162,26 +163,31 @@ static int blkzone_report(struct blkzone_control *ctl)
 {
 	struct blk_zone_report *zi;
 	unsigned long zonesize;
-	uint32_t i;
+	uint32_t i, nr_zones;
 	int fd;
 
 	fd = init_device(ctl, O_RDONLY);
 
 	if (ctl->offset > ctl->total_sectors)
 		errx(EXIT_FAILURE, _("%s: offset is greater than device size"), ctl->devname);
-	if (ctl->length < 1) {
-		zonesize = blkdev_chunk_sectors(ctl->devname);
-		if (!zonesize)
-			errx(EXIT_FAILURE, _("%s: unable to determine zone size"), ctl->devname);
-		ctl->length = 1 + (ctl->total_sectors - ctl->offset) / zonesize;
-	}
+
+	zonesize = blkdev_chunk_sectors(ctl->devname);
+	if (!zonesize)
+		errx(EXIT_FAILURE, _("%s: unable to determine zone size"), ctl->devname);
+
+	if (ctl->count)
+		nr_zones = ctl->count;
+	else if (ctl->length)
+		nr_zones = (ctl->length + zonesize - 1) / zonesize;
+	else
+		nr_zones = 1 + (ctl->total_sectors - ctl->offset) / zonesize;
 
 	zi = xmalloc(sizeof(struct blk_zone_report) +
 		     (DEF_REPORT_LEN * sizeof(struct blk_zone)));
 
-	while (ctl->length && ctl->offset < ctl->total_sectors) {
+	while (nr_zones && ctl->offset < ctl->total_sectors) {
 
-		zi->nr_zones = min(ctl->length, (uint64_t)DEF_REPORT_LEN);
+		zi->nr_zones = min(nr_zones, DEF_REPORT_LEN);
 		zi->sector = ctl->offset;
 
 		if (ioctl(fd, BLKREPORTZONE, zi) == -1)
@@ -192,7 +198,7 @@ static int blkzone_report(struct blkzone_control *ctl)
 				zi->nr_zones, ctl->offset);
 
 		if (!zi->nr_zones) {
-			ctl->length = 0;
+			nr_zones = 0;
 			break;
 		}
 
@@ -205,7 +211,7 @@ static int blkzone_report(struct blkzone_control *ctl)
 			uint64_t len = entry->len;
 
 			if (!len) {
-				ctl->length = 0;
+				nr_zones = 0;
 				break;
 			}
 
@@ -216,7 +222,7 @@ static int blkzone_report(struct blkzone_control *ctl)
 				cond, condition_str[cond & ARRAY_SIZE(condition_str)],
 				type, type_text[type]);
 
-			ctl->length--;
+			nr_zones--;
 			ctl->offset = start + len;
 
 		}
@@ -246,31 +252,39 @@ static int blkzone_reset(struct blkzone_control *ctl)
 	fd = init_device(ctl, O_WRONLY);
 
 	if (ctl->offset & (zonesize - 1))
-		errx(EXIT_FAILURE, _("%s: zone %" PRIu64 " is not aligned "
+		errx(EXIT_FAILURE, _("%s: offset %" PRIu64 " is not aligned "
 			"to zone size %" PRIu64),
 			ctl->devname, ctl->offset, zonesize);
 
 	if (ctl->offset > ctl->total_sectors)
 		errx(EXIT_FAILURE, _("%s: offset is greater than device size"), ctl->devname);
 
-	if (!ctl->length)
-		zlen = ctl->total_sectors;
+	if (ctl->count)
+		zlen = ctl->count * zonesize;
+	else if (ctl->length)
+		zlen = ctl->length;
 	else
-		zlen = ctl->length * zonesize;
+		zlen = ctl->total_sectors;
 	if (ctl->offset + zlen > ctl->total_sectors)
 		zlen = ctl->total_sectors - ctl->offset;
 
+	if (ctl->length &&
+	    (zlen & (zonesize - 1)) &&
+	    ctl->offset + zlen != ctl->total_sectors)
+		errx(EXIT_FAILURE, _("%s: number of sectors %" PRIu64 " is not aligned "
+			"to zone size %" PRIu64),
+			ctl->devname, ctl->length, zonesize);
+
 	za.sector = ctl->offset;
 	za.nr_sectors = zlen;
 
 	if (ioctl(fd, BLKRESETZONE, &za) == -1)
 		err(EXIT_FAILURE, _("%s: BLKRESETZONE ioctl failed"), ctl->devname);
-
 	else if (ctl->verbose)
 		printf(_("%s: successfully reset in range from %" PRIu64 ", to %" PRIu64),
 			ctl->devname,
 			ctl->offset,
-			zlen);
+			ctl->offset + zlen);
 	close(fd);
 	return 0;
 }
@@ -291,7 +305,8 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 
 	fputs(USAGE_OPTIONS, out);
 	fputs(_(" -o, --offset <sector>  start sector of zone to act (in 512-byte sectors)\n"), out);
-	fputs(_(" -l, --length <number>  maximum number of zones\n"), out);
+	fputs(_(" -l, --length <sectors>  maximum sectors to act (in 512-byte sectors)\n"), out);
+	fputs(_(" -c, --count <number>  maximum number of zones\n"), out);
 	fputs(_(" -v, --verbose          display more details\n"), out);
 	fputs(USAGE_SEPARATOR, out);
 	fputs(USAGE_HELP, out);
@@ -304,11 +319,17 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 int main(int argc, char **argv)
 {
 	int c;
-	struct blkzone_control ctl = { .devname = NULL };
+	struct blkzone_control ctl = {
+		.devname = NULL,
+		.offset = 0,
+		.count = 0,
+		.length = 0
+	};
 
 	static const struct option longopts[] = {
 	    { "help",    no_argument,       NULL, 'h' },
-	    { "length",  required_argument, NULL, 'l' }, /* max #of zones (entries) for result */
+	    { "count",  required_argument, NULL, 'c' }, /* max #of zones to operate on */
+	    { "length",  required_argument, NULL, 'l' }, /* max of sectors to operate on */
 	    { "offset",  required_argument, NULL, 'o' }, /* starting LBA */
 	    { "verbose", no_argument,       NULL, 'v' },
 	    { "version", no_argument,       NULL, 'V' },
@@ -328,14 +349,18 @@ int main(int argc, char **argv)
 		argc--;
 	}
 
-	while ((c = getopt_long(argc, argv, "hl:o:vV", longopts, NULL)) != -1) {
+	while ((c = getopt_long(argc, argv, "hc:l:o:vV", longopts, NULL)) != -1) {
 		switch (c) {
 		case 'h':
 			usage(stdout);
 			break;
+		case 'c':
+			ctl.count = strtou32_or_err(optarg,
+					_("failed to parse number of zones"));
+			break;
 		case 'l':
 			ctl.length = strtosize_or_err(optarg,
-					_("failed to parse number of zones"));
+					_("failed to parse number of sectors"));
 			break;
 		case 'o':
 			ctl.offset = strtosize_or_err(optarg,
@@ -355,6 +380,9 @@ int main(int argc, char **argv)
 	if (!ctl.command)
 		errx(EXIT_FAILURE, _("no command specified"));
 
+	if (ctl.count && ctl.length)
+		errx(EXIT_FAILURE, _("zone count and number of sectors cannot be specified together"));
+
 	if (optind == argc)
 		errx(EXIT_FAILURE, _("no device specified"));
 	ctl.devname = argv[optind++];