Re: [code] Unlimited partitions, a try

[Alexander E. Patrakov]

Alan Cox wrote:
> This was proposed ages ago. Al Viro vetoed sparse minors and it has been
> stuck this way ever since. If you have > 15 partitions use device mapper
> for it. I'd prefer it fixed but its arguable that device mapper is the
> right way to punt all our partitioning to userspace.
>   

Then please fix support for extended partitions in kpartx (part of 
multipath-tools). Debian has an incomplete patch that does the right 
thing on activation, but not on deactivation of partitions, and has an 
obvious off-by-one in the "kpartx -l /dev/sda" output.

Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
Edited by Alexander E. Patrakov to fix incorrect output of "kpartx -l"
Signed-off-by: Alexander E. Patrakov <patrakov@xxxxxxxxxx>

--- a/kpartx/kpartx.c
+++ b/kpartx/kpartx.c
@@ -387,10 +387,10 @@ main(int argc, char **argv){
					slices[j].minor = m++;

					start = slices[j].start - slices[k].start;
-					printf("%s%s%d : 0 %lu /dev/dm-%d %lu\n",
+					printf("%s%s%d : 0 %lu %s%s%d %lu\n",
					       mapname, delim, j+1,
					       (unsigned long) slices[j].size,
-					       slices[k].minor, start);
+					       mapname, delim, k+1, start);
					c--;
				}
				/* Terminate loop if nothing more to resolve */
@@ -431,7 +431,7 @@ main(int argc, char **argv){
			break;

		case ADD:
-			for (j=0, c = 0; j<n; j++) {
+			for (j = 0, c = 0; j < n; j++) {
				if (slices[j].size == 0)
					continue;

@@ -477,6 +477,7 @@ main(int argc, char **argv){
			d = c;
			while (c) {
				for (j = 0; j < n; j++) {
+					unsigned long start;
					int k = slices[j].container - 1;

					if (slices[j].size == 0)
@@ -487,7 +488,7 @@ main(int argc, char **argv){
						continue;

					/* Skip all simple slices */
-					if (k < 0)
+					if (slices[j].container == 0)
						continue;

					/* Check container slice */
@@ -502,10 +503,11 @@ main(int argc, char **argv){
					}
					strip_slash(partname);

+					start = slices[j].start - slices[k].start;
					if (safe_sprintf(params, "%d:%d %lu",
							 slices[k].major,
							 slices[k].minor,
-							 (unsigned long)slices[j].start)) {
+							 start)) {
						fprintf(stderr, "params too small\n");
						exit(1);
					}
@@ -524,9 +526,12 @@ main(int argc, char **argv){
						&slices[j].minor);

					if (verbose)
-						printf("add map %s : 0 %lu %s %s\n",
-						       partname, slices[j].size,
-						       DM_TARGET, params);
+						printf("add map %s (%d:%d): 0 %lu %s\n",
+						       partname, 
+						       slices[j].major,
+						       slices[j].minor,
+						       slices[j].size,
+						       params);
					c--;
				}
				/* Terminate loop */


--
Alexander E. Patrakov
-
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