lsdev device name section headers should be printed by dv_print callback.

lsdev command does walk over devsw list, prints list element name and
will use dv_print() callback to print the device list.
Unfortunately this approach will add unneeded noise when there are no
particular devices detected.

To remove "empty" device section headers, the dv_print() callback
should print the header instead.

In addition, fixed dv_print callback for md module.

Reviewed by:	imp
Approved by:	imp (mentor)
Differential Revision:	https://reviews.freebsd.org/D8551

sys/boot/common/commands.c

@@ -497,10 +497,8 @@ command_lsdev(int argc, char *argv[])
     pager_open();
     for (i = 0; devsw[i] != NULL; i++) {
 	if (devsw[i]->dv_print != NULL){
-	    sprintf(line, "%s devices:\n", devsw[i]->dv_name);
-	    if (pager_output(line))
-		    break;
-	    devsw[i]->dv_print(verbose);
+	    if (devsw[i]->dv_print(verbose))
+		break;
 	} else {
 	    sprintf(line, "%s: (unknown)\n", devsw[i]->dv_name);
 	    if (pager_output(line))

sys/boot/common/dev_net.c

@@ -332,11 +332,18 @@ net_print(int verbose)
 	int i, d, cnt;
 	int ret = 0;
 
+	if (netif_drivers[0] == NULL)
+		return (ret);
+
+	printf("%s devices:", netdev.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	cnt = 0;
 	for (d = 0; netif_drivers[d]; d++) {
 		drv = netif_drivers[d];
 		for (i = 0; i < drv->netif_nifs; i++) {
-			printf("\t%s%d:", "net", cnt++);
+			printf("\t%s%d:", netdev.dv_name, cnt++);
 			if (verbose) {
 				printf(" (%s%d)", drv->netif_bname,
 				    drv->netif_ifs[i].dif_unit);

sys/boot/common/md.c

@@ -63,7 +63,7 @@ static int md_init(void);
 static int md_strategy(void *, int, daddr_t, size_t, size_t, char *, size_t *);
 static int md_open(struct open_file *, ...);
 static int md_close(struct open_file *);
-static void md_print(int);
+static int md_print(int);
 
 struct devsw md_dev = {
 	"md",
@@ -143,9 +143,14 @@ md_close(struct open_file *f)
 	return ((dev->d_unit != 0) ? ENXIO : 0);
 }
 
-static void
+static int
 md_print(int verbose)
 {
 
-	printf("MD (%u bytes)\n", MD_IMAGE_SIZE);
+	printf("%s devices:", md_dev.dv_name);
+	if (pager_output("\n") != 0)
+		return (1);
+
+	printf("MD (%u bytes)", MD_IMAGE_SIZE);
+	return (pager_output("\n"));
 }

sys/boot/efi/libefi/efinet.c

@@ -353,6 +353,10 @@ efinet_dev_print(int verbose)
 	EFI_HANDLE h;
 	int unit, ret = 0;
 
+	printf("%s devices:", efinet_dev.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	for (unit = 0, h = efi_find_handle(&efinet_dev, 0);
 	    h != NULL; h = efi_find_handle(&efinet_dev, ++unit)) {
 		printf("    %s%d:", efinet_dev.dv_name, unit);

sys/boot/efi/libefi/efipart.c

@@ -172,6 +172,10 @@ efipart_print(int verbose)
 	u_int unit;
 	int ret = 0;
 
+	printf("%s devices:", efipart_dev.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	for (unit = 0, h = efi_find_handle(&efipart_dev, 0);
 	    h != NULL; h = efi_find_handle(&efipart_dev, ++unit)) {
 		snprintf(line, sizeof(line), "    %s%d:",

sys/boot/i386/libfirewire/firewire.c

@@ -155,6 +155,10 @@ fw_print(int verbose)
 	int i, ret = 0;
 	struct fwohci_softc *sc;
 
+	printf("%s devices:", fwohci.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	for (i = 0; i < MAX_OHCI; i ++) {
 		sc = &fwinfo[i];
 		if (sc->state == FWOHCI_STATE_DEAD)

sys/boot/i386/libi386/bioscd.c

@@ -183,6 +183,13 @@ bc_print(int verbose)
 	char line[80];
 	int i, ret = 0;
 
+	if (nbcinfo == 0)
+		return (0);
+
+	printf("%s devices:", bioscd.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	for (i = 0; i < nbcinfo; i++) {
 		snprintf(line, sizeof(line), "    cd%d: Device 0x%x\n", i,
 		    bcinfo[i].bc_sp.sp_devicespec);

sys/boot/i386/libi386/biosdisk.c

@@ -328,6 +328,13 @@ bd_print(int verbose)
 	struct disk_devdesc dev;
 	int i, ret = 0;
 
+	if (nbdinfo == 0)
+		return (0);
+
+	printf("%s devices:", biosdisk.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	for (i = 0; i < nbdinfo; i++) {
 		snprintf(line, sizeof(line),
 		    "    disk%d:   BIOS drive %c (%ju X %u):\n", i,

sys/boot/i386/libi386/pxe.c

@@ -389,6 +389,9 @@ pxe_print(int verbose)
 	if (pxe_call == NULL)
 		return (0);
 
+	printf("%s devices:", pxedisk.dv_name);
+	if (pager_output("\n") != 0)
+		return (1);
 	if (verbose) {
 		snprintf(line, sizeof(line), "    pxe0:    %s:%s\n",
 		    inet_ntoa(rootip), rootpath);

sys/boot/mips/beri/loader/beri_disk_cfi.c

@@ -119,6 +119,10 @@ beri_cfi_disk_print(int verbose)
 	char line[80];
 	int ret;
 
+	printf("%s devices:", beri_cfi_disk.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	snprintf(line, sizeof(line), "    cfi%d   CFI flash device\n", 0);
 	ret = pager_output(line);
 	if (ret != 0)

sys/boot/mips/beri/loader/beri_disk_sdcard.c

@@ -125,6 +125,10 @@ beri_sdcard_disk_print(int verbose)
 	char line[80];
 	int ret;
 
+	printf("%s devices:", beri_sdcard_disk.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+	
 	snprintf(line, sizeof(line), "    sdcard%d   Altera SD card drive\n", 0);
 	ret = pager_output(line);
 	if (ret != 0)

sys/boot/pc98/libpc98/bioscd.c

@@ -179,6 +179,13 @@ bc_print(int verbose)
 	char line[80];
 	int i, ret = 0;
 
+	if (nbcinfo == 0)
+		return (0);
+
+	printf("%s devices:", bioscd.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	for (i = 0; i < nbcinfo; i++) {
 		sprintf(line, "    cd%d: Device 0x%x\n", i,
 		    bcinfo[i].bc_sp.sp_devicespec);

sys/boot/pc98/libpc98/biosdisk.c

@@ -258,6 +258,13 @@ bd_print(int verbose)
     struct open_disk		*od;
     struct pc98_partition	*dptr;
     
+    if (nbdinfo == 0)
+	return (0);
+
+    printf("%s devices:", biosdisk.dv_name);
+    if ((ret = pager_output("\n")) != 0)
+	return (ret);
+
     for (i = 0; i < nbdinfo; i++) {
 	snprintf(line, sizeof(line), "    disk%d:   BIOS drive %c:\n",
 	    i, 'A' + i);

sys/boot/uboot/lib/disk.c

@@ -245,6 +245,13 @@ stor_print(int verbose)
 	static char line[80];
 	int i, ret = 0;
 
+	if (stor_info_no == 0)
+		return (ret);
+
+	printf("%s devices:", uboot_storage.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	for (i = 0; i < stor_info_no; i++) {
 		dev.d_dev = &uboot_storage;
 		dev.d_unit = i;

sys/boot/usb/storage/umass_loader.c

@@ -175,6 +175,10 @@ umass_disk_print(int verbose)
 {
 	struct disk_devdesc dev;
 
+	printf("%s devices:", umass_disk.dv_name);
+	if (pager_output("\n") != 0)
+		return (1);
+
 	memset(&dev, 0, sizeof(dev));
 
 	ret = pager_output("    umass0   UMASS device\n");

sys/boot/userboot/userboot/host.c

@@ -139,6 +139,10 @@ host_dev_print(int verbose)
 {
 	char line[80];
 
+	printf("%s devices:", host_dev.dv_name);
+	if (pager_output("\n") != 0)
+		return (1);
+
 	snprintf(line, sizeof(line), "    host%d:   Host filesystem\n", 0);
 	return (pager_output(line));
 }

sys/boot/userboot/userboot/userboot_disk.c

@@ -123,6 +123,13 @@ userdisk_print(int verbose)
 	char line[80];
 	int i, ret = 0;
 
+	if (userdisk_maxunit == 0)
+		return (0);
+
+	printf("%s devices:", userboot_disk.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	for (i = 0; i < userdisk_maxunit; i++) {
 		snprintf(line, sizeof(line),
 		    "    disk%d:   Guest drive image\n", i);

sys/boot/zfs/zfs.c

@@ -521,6 +521,13 @@ zfs_dev_print(int verbose)
 	char line[80];
 	int ret = 0;
 
+	if (STAILQ_EMPTY(&zfs_pools))
+		return (0);
+
+	printf("%s devices:", zfs_dev.dv_name);
+	if ((ret = pager_output("\n")) != 0)
+		return (ret);
+
 	if (verbose) {
 		return (spa_all_status());
 	}