On 11/17/21 11:40 AM, Christian Storm via lists.cip-project.org wrote:

From: Quirin Gylstorff <quirin.gylstorff@...>

Backport the following patches to detect the correct partition to
update.
388f1777 util: Add get_root source /proc/self/mountinfo
3914d2b7 util: Extend get_root to find LUKS devices

Why not upgrade to a newer version of SWUpdate instead of backporting
stuff? There's no real advantage to stay on a "release" as SWUpdate
follows rolling releases -- granted, you have to do the qualification
but that applies to "releases" as well...

The build of SWUpdate uses dpkg-gbp to follow the Debian build of SWUpdate with sources from [1].

As Debian only follows fixed release , currently 2021.04, I patched the version.
This patchset is no longer necessary after Debian uses the next Release
SWUpdate version.

[1]: https://salsa.debian.org/debian/swupdate.

Signed-off-by: Quirin Gylstorff <quirin.gylstorff@...>
---
.../0001-add-patches-for-dm-verity.patch | 188 ++++++++++++++++++
.../swupdate/swupdate_2021.04-1+debian-gbp.bb | 5 +
2 files changed, 193 insertions(+)
create mode 100644 recipes-core/swupdate/files/0001-add-patches-for-dm-verity.patch

diff --git a/recipes-core/swupdate/files/0001-add-patches-for-dm-verity.patch b/recipes-core/swupdate/files/0001-add-patches-for-dm-verity.patch
new file mode 100644
index 0000000..f143207
--- /dev/null
+++ b/recipes-core/swupdate/files/0001-add-patches-for-dm-verity.patch
@@ -0,0 +1,188 @@
+From 4650883c2ffc4ed9e479e1eefdce044067c7de0b Mon Sep 17 00:00:00 2001
+From: Quirin Gylstorff <quirin.gylstorff@...>
+Date: Mon, 25 Oct 2021 14:43:07 +0200
+Subject: [PATCH] add patches for dm-verity
+
+Signed-off-by: Quirin Gylstorff <quirin.gylstorff@...>
+---
+ ...d-get_root-source-proc-self-mountinfo.diff | 68 +++++++++++++++
+ ...-Extend-get_root-to-find-LUKS-devices.diff | 83 +++++++++++++++++++
+ debian/patches/series | 2 +
+ 3 files changed, 153 insertions(+)
+ create mode 100644 debian/patches/0001-util-Add-get_root-source-proc-self-mountinfo.diff
+ create mode 100644 debian/patches/0002-util-Extend-get_root-to-find-LUKS-devices.diff
+
+diff --git a/debian/patches/0001-util-Add-get_root-source-proc-self-mountinfo.diff b/debian/patches/0001-util-Add-get_root-source-proc-self-mountinfo.diff
+new file mode 100644
+index 0000000..5db0e61
+--- /dev/null
++++ b/debian/patches/0001-util-Add-get_root-source-proc-self-mountinfo.diff
+@@ -0,0 +1,68 @@
++From 388f1777e3e9e7dfbe41768aa7ce86bc0ee25c37 Mon Sep 17 00:00:00 2001
++From: Christian Storm <christian.storm@...>
++Date: Thu, 10 Jun 2021 00:30:24 +0200
++Subject: [PATCH 1/2] util: Add get_root source /proc/self/mountinfo
++
++Filesystems such as BTRFS report synthetic device major:minor
++numbers in stat(2)'s st_dev value. Hence, such a root filesystem
++won't be found by get_root_from_partitions().
++
++As /proc/self/mountinfo's information is subject to mount-
++namespacing, it complements get_root_from_partitions() rather
++than replacing it.
++
++Signed-off-by: Christian Storm <christian.storm@...>
++Signed-off-by: Quirin Gylstorff <quirin.gylstorff@...>

Hm, why is your sign-off needed here as you've grabbed that directly
from SWUpdate's repo?

I will fix it in a new version.

++---
++ core/util.c | 28 ++++++++++++++++++++++++++++
++ 1 file changed, 28 insertions(+)
++
++diff --git a/core/util.c b/core/util.c
++index 7d7673a..51a16b6 100644
++--- a/core/util.c
+++++ b/core/util.c
++@@ -883,6 +883,32 @@ static char *get_root_from_partitions(void)
++ return NULL;
++ }
++
+++/*
+++ * Return the rootfs's device name from /proc/self/mountinfo.
+++ * Needed for filesystems having synthetic stat(2) st_dev
+++ * values such as BTRFS.
+++ */
+++static char *get_root_from_mountinfo(void)
+++{
+++ char *mnt_point, *device = NULL;
+++ FILE *fp = fopen("/proc/self/mountinfo", "r");
+++ while (fp && !feof(fp)){
+++ /* format: https://www.kernel.org/doc/Documentation/filesystems/proc.txt */
+++ if (fscanf(fp, "%*s %*s %*u:%*u %*s %ms %*s %*[-] %*s %ms %*s",
+++ &mnt_point, &device) == 2) {
+++ if ( (!strcmp(mnt_point, "/")) && (strcmp(device, "none")) ) {
+++ free(mnt_point);
+++ break;
+++ }
+++ free(mnt_point);
+++ free(device);
+++ }
+++ device = NULL;
+++ }
+++ (void)fclose(fp);
+++ return device;
+++}
+++
++ #define MAX_CMDLINE_LENGTH 4096
++ static char *get_root_from_cmdline(void)
++ {
++@@ -936,6 +962,8 @@ char *get_root_device(void)
++ root = get_root_from_partitions();
++ if (!root)
++ root = get_root_from_cmdline();
+++ if (!root)
+++ root = get_root_from_mountinfo();
++
++ return root;
++ }
++--
++2.30.2
++
+diff --git a/debian/patches/0002-util-Extend-get_root-to-find-LUKS-devices.diff b/debian/patches/0002-util-Extend-get_root-to-find-LUKS-devices.diff
+new file mode 100644
+index 0000000..a62d59c
+--- /dev/null
++++ b/debian/patches/0002-util-Extend-get_root-to-find-LUKS-devices.diff
+@@ -0,0 +1,83 @@
++From 3914d2b73bf80b24aba015d9225082c2965c7a02 Mon Sep 17 00:00:00 2001
++From: Stefano Babic <sbabic@...>
++Date: Thu, 10 Jun 2021 16:14:44 +0200
++Subject: [PATCH 2/2] util: Extend get_root to find LUKS devices
++
++This helps in case of encrypted filesystem or device mapper.
++The returned device read from partitions is usually a dm-X device and
++this does not show which is the block device that contains it. Look in
++sysfs and check if the device has "slaves" entries, indicating the
++presence of an underlying device. If found, return this instead of the
++device returned parsing /proc/partitions.
++
++Signed-off-by: Stefano Babic <sbabic@...>
++Signed-off-by: Quirin Gylstorff <quirin.gylstorff@...>

Same question as above applies here.

New version is in work

++---
++ core/util.c | 26 ++++++++++++++++++++++++--
++ 1 file changed, 24 insertions(+), 2 deletions(-)
++
++diff --git a/core/util.c b/core/util.c
++index 51a16b6..3b81c09 100644
++--- a/core/util.c
+++++ b/core/util.c
++@@ -24,6 +24,7 @@
++ #include <libgen.h>
++ #include <regex.h>
++ #include <string.h>
+++#include <dirent.h>
++
++ #if defined(__linux__)
++ #include <sys/statvfs.h>
++@@ -851,6 +852,10 @@ size_t snescape(char *dst, size_t n, const char *src)
++ /*
++ * This returns the device name where rootfs is mounted
++ */
+++
+++static int filter_slave(const struct dirent *ent) {
+++ return (strcmp(ent->d_name, ".") && strcmp(ent->d_name, ".."));
+++}
++ static char *get_root_from_partitions(void)
++ {
++ struct stat info;
++@@ -858,11 +863,28 @@ static char *get_root_from_partitions(void)
++ char *devname = NULL;
++ unsigned long major, minor, nblocks;
++ char buf[256];
++- int ret;
+++ int ret, dev_major, dev_minor, n;
+++ struct dirent **devlist = NULL;
++
++ if (stat("/", &info) < 0)
++ return NULL;
++
+++ dev_major = info.st_dev / 256;
+++ dev_minor = info.st_dev % 256;
+++
+++ /*
+++ * Check if this is just a container, for example in case of LUKS
+++ * Search if the device has slaves pointing to another device
+++ */
+++ snprintf(buf, sizeof(buf) - 1, "/sys/dev/block/%d:%d/slaves", dev_major, dev_minor);
+++ n = scandir(buf, &devlist, filter_slave, NULL);
+++ if (n == 1) {
+++ devname = strdup(devlist[0]->d_name);
+++ free(devlist);
+++ return devname;
+++ }
+++ free(devlist);
+++
++ fp = fopen("/proc/partitions", "r");
++ if (!fp)
++ return NULL;
++@@ -872,7 +894,7 @@ static char *get_root_from_partitions(void)
++ &major, &minor, &nblocks, &devname);
++ if (ret != 4)
++ continue;
++- if ((major == info.st_dev / 256) && (minor == info.st_dev % 256)) {
+++ if ((major == dev_major) && (minor == dev_minor)) {
++ fclose(fp);
++ return devname;
++ }
++--
++2.30.2
++
+diff --git a/debian/patches/series b/debian/patches/series
+index 8c5564a..f3bd00e 100644
+--- a/debian/patches/series
++++ b/debian/patches/series
+@@ -1 +1,3 @@
+ use-gcc-compiler.diff
++0002-util-Extend-get_root-to-find-LUKS-devices.diff
++0001-util-Add-get_root-source-proc-self-mountinfo.diff
+--
+2.30.2
+
diff --git a/recipes-core/swupdate/swupdate_2021.04-1+debian-gbp.bb b/recipes-core/swupdate/swupdate_2021.04-1+debian-gbp.bb
index 7a0fb9b..90854a4 100644
--- a/recipes-core/swupdate/swupdate_2021.04-1+debian-gbp.bb
+++ b/recipes-core/swupdate/swupdate_2021.04-1+debian-gbp.bb
@@ -25,6 +25,11 @@ SRC_URI += "file://0001-debian-Add-option-to-build-with-efibootguard.patch \
file://0007-debian-Make-CONFIG_HW_COMPATIBILTY-optional.patch \
file://0008-debian-rules-Add-Embedded-Lua-handler-option.patch"
+# Patch for dm-verity based images - can be removed with SWUpdate 2021.10
+SRC_URI += "file://0001-add-patches-for-dm-verity.patch"
+
+# end patching for dm-verity based images
+
# deactivate signing and encryption for simple a/b rootfs update
SWUPDATE_BUILD_PROFILES += "pkg.swupdate.nosigning pkg.swupdate.noencryption"
--
2.30.2

Kind regards,
Christian

Quirin