Bug 13658

Summary:

Unable to resize extended partition in image created with wic

Product:

[Build System, Metadata & Runtime] OE-Core

Reporter:

Preeti Sachan <preetischn>

Component:

Scripts and Tools

Assignee:

Chee Yang <chee.yang.lee>

Status:

RESOLVED FIXED

QA Contact:

Severity:

critical

Priority:

Medium+

CC:

randy.macleod, richard.purdie, ross.burton, tim.orling

Version:

unspecified

Target Milestone:

3.1 M4

Hardware:

All

OS:

Multiple

Whiteboard:

OS type for building Yocto:

---

Type of Regression:

---

Verified:

Documentation change:

No (bug/feature does not impact docs)

Attachments:

Description	Flags
patch file applicable to poky, sumo and thud branch	none

Description Preeti Sachan 2019-11-26 07:43:09 UTC

I have created wic image having extended partitions with below *.wks file content.

wks file:

part /mnt/boot --ondisk mmcblk0 --label edgeos-boot --active --fixed-size=100M --fstype=vfat --align 4096 --source bootimg-partition
part /mnt/krn1 --ondisk mmcblk0 --label edgeos-krn1 --fstype=vfat --align 4096 --fixed-size=64M --source rawcopy --sourceparams="file=kernel.vfat"
part /mnt/krn2 --ondisk mmcblk0 --label edgeos-krn2 --fstype=vfat --align 4096 --fixed-size=64M
part /mnt/rootfs-container --ondisk mmcblk0 --label edgeos-cntnr --fstype=ext3 --align 4096 --fixed-size=512M --source rootfs --rootfs-dir=rootfs-image-dir
part /mnt/conf --ondisk mmcblk0 --label edgeos-conf --fstype=ext3 --align 4096 --fixed-size=16M
part /mnt/data --ondisk mmcblk0 --label edgeos-data --fstype=ext3 --align 4096 --fixed-size=512M

fdisk output:

# fdisk -l /dev/mmcblk0
Disk /dev/mmcblk0: 14.9 GiB, 15987638272 bytes, 31225856 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x6f201fb9

Device         Boot   Start      End  Sectors  Size Id Type
/dev/mmcblk0p1 *       8192   212991   204800  100M  c W95 FAT32 (LBA)
/dev/mmcblk0p2       212992   344063   131072   64M  c W95 FAT32 (LBA)
/dev/mmcblk0p3       344064   475135   131072   64M  c W95 FAT32 (LBA)
/dev/mmcblk0p4       483327  2629631  2146305    1G  f W95 Ext'd (LBA)
/dev/mmcblk0p5       483328  1531903  1048576  512M 83 Linux
/dev/mmcblk0p6      1540096  1572863    32768   16M 83 Linux
/dev/mmcblk0p7      1581056  2629631  1048576  512M 83 Linux


When performing resizing of extended partition using 'parted' tool after booting wic image (or at boot time via systemd service file), it is giving error "Unable to satisfy all constraints on the partition."

command:  "parted /dev/mmcblk0 resizepart 4 -1s"


This error "Unable to satisfy all constraints on the partition." is coming due to invalid created msdos partition table via wic. There are the basic partition rules for msdos partition table and need to be followed while creating wic image for extended partition. Refer link https://gparted.org/h2-fix-msdos-pt.php.

According to rule, atleast 2 unallocated sectors are required in front of a logical partition. This space is required for the Extended Boot Record (EBR).

But the generated wic image having only one sector gap between extended partition (start: 483327) and 1st logical partition (start: 483328).

There is bug in imager file direct.py. (https://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/scripts/lib/wic/plugins/imager/direct.py?h=master) at line 406, 449 and 514.

line 403-406:
                # Reserve a sector for EBR for every logical partition
                # before alignment is performed.
                if part.type == 'logical':
                    self.offset += 1

line 449:
                  self.extended_size_sec += part.size_sec + 1

line 514-516:

self._create_partition(self.path, "extended",
                                       None, part.start - 1,
                                       self.extended_size_sec)

In above mentioned line, it is keeping 1 sector gap between extended partition and 1st logical partition instead of keeping minimum 2 sector gap. Please look into this issue.


Thanks and Regards
Preeti Sachan

Comment 1 Richard Purdie 2019-12-05 15:48:52 UTC

Is this simply a case of changing the += 1 to +=2 ? Could someone send a patch please if so?

Comment 2 Preeti Sachan 2019-12-06 08:42:41 UTC

Created attachment 4594 [details]
patch file applicable to poky, sumo and thud branch

Comment 3 Preeti Sachan 2019-12-06 08:46:09 UTC

I have tested on poky sumo and thud branch and having patch for same.
This patch file is applicable to poky sumo and thud branch.

$ cat fix-parted-unable-to-satisfy-all-constraints.patch
diff --git a/scripts/lib/wic/plugins/imager/direct.py b/scripts/lib/wic/plugins/imager/direct.py
index 1fa6b91..57f6f4a 100644
--- a/scripts/lib/wic/plugins/imager/direct.py
+++ b/scripts/lib/wic/plugins/imager/direct.py
@@ -416,7 +416,7 @@ class PartitionedImage():
                 # Reserve a sector for EBR for every logical partition
                 # before alignment is performed.
                 if self.ptable_format == "msdos":
-                    self.offset += 1
+                    self.offset += 2

             if part.align:
                 # If not first partition and we do have alignment set we need
@@ -517,8 +517,8 @@ class PartitionedImage():
                 # add a sector at the back, so that there is enough
                 # room for all logical partitions.
                 self._create_partition(self.path, "extended",
-                                       None, part.start - 1,
-                                       self.offset - part.start + 1)
+                                       None, part.start - 2,
+                                       self.offset - part.start + 2)

             if part.fstype == "swap":
                 parted_fs_type = "linux-swap"

Comment 4 Chee Yang 2020-03-25 05:00:21 UTC

this should work for master branch
https://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=590555e3b8ccbd94b628aa6778adea7f4538d966