[dm-devel] [PATCH] kpartx: Add -P option for partition scanning

[Ritika Srivastava]

Add -P, partition scanning option to kpartx which would set
LO_FLAGS_PARTSCAN flag during loop device creation.
This option is same as losetup -P option.

Signed-off-by: Ritika Srivastava <ritika.srivastava at oracle.com>
---
 kpartx/kpartx.c | 17 +++++++++++++----
 kpartx/lopart.c |  5 ++++-
 kpartx/lopart.h |  2 +-
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/kpartx/kpartx.c b/kpartx/kpartx.c
index 3c49999..a26d0a2 100644
--- a/kpartx/kpartx.c
+++ b/kpartx/kpartx.c
@@ -87,7 +87,7 @@ initpts(void)
 	addpts("ps3", read_ps3_pt);
 }
 
-static char short_opts[] = "rladfgvp:t:snu";
+static char short_opts[] = "rladfPgvp:t:snu";
 
 /* Used in gpt.c */
 int force_gpt=0;
@@ -98,7 +98,7 @@ static int
 usage(void) {
 	printf(VERSION_STRING);
 	printf("Usage:\n");
-	printf("  kpartx [-a|-d|-u|-l] [-r] [-p] [-f] [-g] [-s|-n] [-v] wholedisk\n");
+	printf("  kpartx [-a|-d|-u|-l] [-r] [-p] [-f] [-g] [-s|-n] [-v] [-P] wholedisk\n");
 	printf("\t-a add partition devmappings\n");
 	printf("\t-r devmappings will be readonly\n");
 	printf("\t-d del partition devmappings\n");
@@ -110,6 +110,7 @@ usage(void) {
 	printf("\t-v verbose\n");
 	printf("\t-n nosync mode. Return before the partitions are created\n");
 	printf("\t-s sync mode (Default). Don't return until the partitions are created\n");
+	printf("\t-P create partitioned loop device\n");
 	return 1;
 }
 
@@ -228,7 +229,7 @@ xmalloc (size_t size) {
 
 int
 main(int argc, char **argv){
-	int i, j, m, n, op, off, arg, c, d, ro=0;
+	int i, j, m, n, op, off, arg, c, d, ro=0, partscan = 0;
 	int fd = -1;
 	struct slice all;
 	struct pt *ptp;
@@ -311,6 +312,9 @@ main(int argc, char **argv){
 		case 'u':
 			what = UPDATE;
 			break;
+		case 'P':
+			partscan = 1;
+			break;
 		default:
 			usage();
 			exit(1);
@@ -328,6 +332,11 @@ main(int argc, char **argv){
 		exit(1);
 	}
 
+	if (what != ADD && partscan == 1)       {
+		printf("-P option is allowed only during loop device setup\n");
+		exit(1);
+	}
+
 	if (hotplug) {
 		/* already got [disk]device */
 	} else if (optind == argc-2) {
@@ -359,7 +368,7 @@ main(int argc, char **argv){
 			exit (0);
 
 		if (!loopdev) {
-			if (set_loop(&loopdev, rpath, 0, &ro)) {
+			if (set_loop(&loopdev, rpath, 0, &ro, partscan)) {
 				fprintf(stderr, "can't set up loop\n");
 				exit (1);
 			}
diff --git a/kpartx/lopart.c b/kpartx/lopart.c
index 512a59f..9a1ce48 100644
--- a/kpartx/lopart.c
+++ b/kpartx/lopart.c
@@ -233,7 +233,8 @@ no_loop_fd:
 	return NULL;
 }
 
-int set_loop(char **device, const char *file, int offset, int *loopro)
+int set_loop(char **device, const char *file, int offset, int *loopro,
+	     int partscan)
 {
 	struct loop_info loopinfo;
 	int fd = -1, ret = 1, ffd, mode;
@@ -264,6 +265,8 @@ int set_loop(char **device, const char *file, int offset, int *loopro)
 	loopinfo.lo_offset = offset;
 	loopinfo.lo_encrypt_type = LO_CRYPT_NONE;
 	loopinfo.lo_encrypt_key_size = 0;
+	if (partscan == 1)
+		loopinfo.lo_flags |= LO_FLAGS_PARTSCAN;
 
 	if (ioctl(fd, LOOP_SET_FD, (void*)(uintptr_t)(ffd)) < 0) {
 		perror ("ioctl: LOOP_SET_FD");
diff --git a/kpartx/lopart.h b/kpartx/lopart.h
index c73ab23..81534e2 100644
--- a/kpartx/lopart.h
+++ b/kpartx/lopart.h
@@ -1,4 +1,4 @@
 extern int verbose;
-extern int set_loop (char **, const char *, int, int *);
+extern int set_loop (char **, const char *, int, int *, int);
 extern int del_loop (const char *);
 extern char * find_loop_by_file (const char *);
-- 
2.27.0