From 5cc378e4cdeb957b405e0264a09295eda7d75ff7 Mon Sep 17 00:00:00 2001

From: Scott Moser <smoser@ubuntu.com>

Date: Mon, 13 Jan 2014 15:32:49 -0500

Subject: [PATCH] partx: fix --update ranges and out of order tables

partx --update DEVICE NUMBER

was broken in 2 cases:

 * if NUMBER != 1

 * if the partition table was "out of order".

   Ie, where sda2 came after sda3.

References: https://bugs.launchpad.net/ubuntu/+source/cloud-utils/+bug/1244662

Signed-off-by: Scott Moser <smoser@ubuntu.com>

Signed-off-by: Karel Zak <kzak@redhat.com>

---

 disk-utils/partx.c | 75 ++++++++++++++++++++++++++++++++++++------------------

 1 file changed, 50 insertions(+), 25 deletions(-)

diff --git a/disk-utils/partx.c b/disk-utils/partx.c

index 880d779..df03e59 100644

--- a/disk-utils/partx.c

+++ b/disk-utils/partx.c

@@ -412,10 +412,41 @@ static void upd_parts_warnx(const char *device, int first, int last)

 				device, first, last);

 }

+/**

+ * get_partition_by_partno:

+ * @ls: partitions list

+ * @n: the partition number (e.g. 'N' from sda'N')

+ *

+ * This does not assume any order of the input blkid_partlist.

+ * And correctly handles "out of order" partition tables.

+ * partition N is located after partition N+1 on the disk.

+ *

+ * Returns: partition object or NULL in case or error.

+ */

+blkid_partition get_partition_by_partno(blkid_partlist ls, int n)

+{

+	int i, nparts;

+	blkid_partition par;

+	if (!ls)

+		return NULL;

+

+	nparts = blkid_partlist_numof_partitions(ls);

+	if (nparts < 0)

+		return NULL;

+

+	for (i = 0; i < nparts; i++) {

+		par = blkid_partlist_get_partition(ls, i);

+		if (n == blkid_partition_get_partno(par)) {

+			return par;

+		}

+	}

+	return NULL;

+}

+

 static int upd_parts(int fd, const char *device, dev_t devno,

 		     blkid_partlist ls, int lower, int upper)

 {

-	int i, n, an, nparts, rc = 0, errfirst = 0, errlast = 0, err;

+	int n, nparts, rc = 0, errfirst = 0, errlast = 0, err;

 	blkid_partition par;

 	uintmax_t start, size;

@@ -441,18 +472,16 @@ static int upd_parts(int fd, const char *device, dev_t devno,

 		return -1;

 	}

-	for (i = 0, n = lower; n <= upper; n++) {

-		par = blkid_partlist_get_partition(ls, i);

-		an = blkid_partition_get_partno(par);

-

-		if (lower && n < lower)

-			continue;

-		if (upper && n > upper)

+	for (n = lower; n <= upper; n++) {

+		par = get_partition_by_partno(ls, n);

+		if (!par) {

+			if (verbose)

+				warn(_("%s: no partition #%d"), device, n);

 			continue;

+		}

 		start = blkid_partition_get_start(par);

 		size =  blkid_partition_get_size(par);

-

 		if (blkid_partition_is_extended(par))

 			/*

 			 * Let's follow the Linux kernel and reduce

@@ -463,25 +492,21 @@ static int upd_parts(int fd, const char *device, dev_t devno,

 		err = partx_del_partition(fd, n);

 		if (err == -1 && errno == ENXIO)

 			err = 0; /* good, it already doesn't exist */

-		if (an == n)

+		if (err == -1 && errno == EBUSY)

 		{

-			if (i < nparts)

-				i++;

-			if (err == -1 && errno == EBUSY)

-			{

-				/* try to resize */

-				err = partx_resize_partition(fd, n, start, size);

-				if (verbose)

-					printf(_("%s: partition #%d resized\n"), device, n);

-				if (err == 0)

-					continue;

-			}

-			if (err == 0 && partx_add_partition(fd, n, start, size) == 0) {

-				if (verbose)

-					printf(_("%s: partition #%d added\n"), device, n);

+			/* try to resize */

+			err = partx_resize_partition(fd, n, start, size);

+			if (verbose)

+				printf(_("%s: partition #%d resized\n"), device, n);

+			if (err == 0)

 				continue;

-			}

 		}

+		if (err == 0 && partx_add_partition(fd, n, start, size) == 0) {

+			if (verbose)

+				printf(_("%s: partition #%d added\n"), device, n);

+			continue;

+		}

+

 		if (err == 0)

 			continue;

 		rc = -1;

-- 

1.9.3