Merge ~rafaeldtinoco/ubuntu/+source/bcache-tools:lp1861941-focal into ubuntu/+source/bcache-tools:ubuntu/focal-devel

[Rafael David Tinoco]

SUMMARY:

BUG: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1861941
TESTCASE: https://paste.ubuntu.com/p/37KGy2Smnp/
PPA: https://launchpad.net/~rafaeldtinoco/+archive/ubuntu/lp1861941

BCACHE-TOOLS:

GROOVY: https://tinyurl.com/yxonp5hz (needs-review for an upload)
FOCAL: https://tinyurl.com/y3tbd3un (needs-review for SRU)
BIONIC: Will be done after Groovy and Focal are reviewed.

SYSTEMD-UDEV:

GROOVY: https://tinyurl.com/y4w22s57 (merged patch rewording, will wait next upload)
FOCAL: https://tinyurl.com/y2uqbyll (merged patch, will ask for an upload - SRU)
BIONIC: Will be done after Groovy and Focal are reviewed.

KERNEL:

After Groovy, Focal and Bionic are fixed (bcache-tools and systemd-udev), I'll send a SRU request for 3 kernels to remove bcache patches created for old bcache/udev rules bug (not needed after this bcache-tools fix).

----

This is basically the same change proposed to Debian and Upstream:

https://github.com/koverstreet/bcache-tools/pull/6/
https://salsa.debian.org/debian/bcache-tools/-/merge_requests/2

Being applied to Groovy to resolve LP: #1861941.

Reviewer: don't worry too much on the functionality but rather the "merge protocol". The MAAS team is doing all the tests in the PPA I'm providing to them:

https://launchpad.net/~rafaeldtinoco/+archive/ubuntu/lp1861941

And, for this merge, being SRU'ed to Focal.

----

Good summary of the issue:

https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1861941/comments/27
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1861941/comments/47
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1861941/comments/56
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1861941/comments/62

And this MR is the bcache-tools fix.

Note: Upstream isn't merging our requests for sometime now, but we are doing all tests at our side to make sure that, even if we have to carry this as a delta (from upstream) it works smoothly.

[Rafael David Tinoco (rafaeldtinoco)]

Positive feedback for focal pkgs from PPA from QA team (testing with MAAS and JuJu):

https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1861941/comments/73

[Rafael David Tinoco (rafaeldtinoco)]

The changes for systemd-udev were pushed into:

https://code.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/+git/systemd/+ref/ubuntu-focal already (after discussion with @ddstreet)

[Christian Ehrhardt  (paelzer)]

waiting for the groovy MP to conclude - only Focal SRU specific feedback is here on this MP:

1. version 1.0.8-3ubuntu1 => 1.0.8-3ubuntu0.1

There could be someone with an ubuntu1 in an interim PPA, versioning rules imply 0.1 being better here.

2. (LP #1861941) => (LP: #1861941)

In the Focal case there wasn't even a former mention of the bug, so make it actively trigger.
Especially important for SRU handling BTW for the tools to find the bug to update.

review: Needs Fixing

[Rafael David Tinoco (rafaeldtinoco)]

Made the same changes as the groovy version.

Based on my answer to:

https://code.launchpad.net/~rafaeldtinoco/ubuntu/+source/bcache-tools/+git/bcache-tools/+merge/387908/comments/1020349

Please let me know if you are +1 for me on uploading this as well, together with the groovy one.

Thank you for reviewing this.

[Christian Ehrhardt  (paelzer)]

Yeah, like on groovy MP +1 now.

review: Approve

[Rafael David Tinoco (rafaeldtinoco)]

c)rafaeldtinoco@focal:~/.../sources/ubuntu/bcache-tools$ git ubuntu tag --upload

(c)rafaeldtinoco@focal:~/.../sources/ubuntu/bcache-tools$ git describe --tags
upload/1.0.8-3ubuntu0.1

$ git push pkg upload/1.0.8-3ubuntu0.1
Enumerating objects: 22, done.
Counting objects: 100% (22/22), done.
Delta compression using up to 8 threads
Compressing objects: 100% (16/16), done.
Writing objects: 100% (16/16), 3.48 KiB | 1.74 MiB/s, done.
Total 16 (delta 11), reused 0 (delta 0)
To ssh://git.launchpad.net/ubuntu/+source/bcache-tools
 * [new tag] upload/1.0.8-3ubuntu0.1 -> upload/1.0.8-3ubuntu0.1

$ debdiff bcache-tools_1.0.8-3.dsc bcache-tools_1.0.8-3ubuntu0.1.dsc | diffstat
 changelog | 7 +++
 control | 5 +-
 patches/0003-Add-bcache-export-cached-helper.patch | 104 +++++++++++++++++++++++++++++++++++++++++++++
 patches/series | 1
 4 files changed, 115 insertions(+), 2 deletions(-)

$ dput ubuntu bcache-tools_1.0.8-3ubuntu0.1_source.changes
Checking signature on .changes
gpg: /home/rafaeldtinoco/work/sources/ubuntu/bcache-tools_1.0.8-3ubuntu0.1_source.changes: Valid signature from A93E0E0AD83C0D0F
Checking signature on .dsc
gpg: /home/rafaeldtinoco/work/sources/ubuntu/bcache-tools_1.0.8-3ubuntu0.1.dsc: Valid signature from A93E0E0AD83C0D0F
Uploading to ubuntu (via ftp to upload.ubuntu.com):
  Uploading bcache-tools_1.0.8-3ubuntu0.1.dsc: done.
  Uploading bcache-tools_1.0.8-3ubuntu0.1.debian.tar.xz: done.
  Uploading bcache-tools_1.0.8-3ubuntu0.1_source.buildinfo: done.
  Uploading bcache-tools_1.0.8-3ubuntu0.1_source.changes: done.
Successfully uploaded packages.

review: Approve

diff --git a/debian/changelog b/debian/changelog
index 7149915..14617c1 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+bcache-tools (1.0.8-3ubuntu0.1) focal; urgency=medium
+
+  [ Ryan Harper ]
+  * Add helper script to read bcache devs superblock (LP: #1861941)
+
+ -- Rafael David Tinoco <[e-mail]>  Thu, 23 Jul 2020 00:33:50 +0000
+
 bcache-tools (1.0.8-3) unstable; urgency=medium
 
   * d/bcache-tools.preinst: fail on unexpected error (Closes: #866250).
diff --git a/debian/control b/debian/control
index 2cedcac..6437f35 100644
--- a/debian/control
+++ b/debian/control
@@ -1,5 +1,6 @@
 Source: bcache-tools
-Maintainer: David Mohr <[e-mail]>
+Maintainer: Ubuntu Developers <[e-mail]>
+XSBC-Original-Maintainer: David Mohr <[e-mail]>
 Uploaders: Robie Basak <[e-mail]>
 Section: utils
 Priority: optional
@@ -11,7 +12,7 @@ Homepage: https://bcache.evilpiepirate.org/
 
 Package: bcache-tools
 Architecture: linux-any
-Depends: ${misc:Depends}, ${shlibs:Depends}
+Depends: ${misc:Depends}, ${shlibs:Depends}, gawk
 Recommends: initramfs-tools | linux-initramfs-tool
 Description: bcache userspace tools
  Bcache allows the use of SSDs to cache other block devices.
diff --git a/debian/patches/0003-Add-bcache-export-cached-helper.patch b/debian/patches/0003-Add-bcache-export-cached-helper.patch
new file mode 100644
index 0000000..ffc6ff1
--- /dev/null
+++ b/debian/patches/0003-Add-bcache-export-cached-helper.patch
@@ -0,0 +1,104 @@
+Description: Add bcache-export-cached helper to export CACHED_UUID and
+ CACHED_LABEL always
+
+Linux kernel bcache driver does not always emit a uevent[1] for when a backing
+device is bound to a bcacheN device.  When this happens, the udev rule for
+creating /dev/bcache/by-uuid or /dev/bcache/by-label symlinks does not fire and
+removes any persistent symlink to a specific backing device since the bcache
+minor numbers (bcache0, 1, 2) are not guaranteed across reboots.
+
+This script reads the superblock of the bcache device slaves, ensuring the
+slave is a backing device via sb.version check, extracts the dev.uuid and
+dev.label values and exports them to udev for triggering the symlink rules in
+the existing rules file.
+
+1. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1729145
+
+Author: Ryan Harper <[e-mail]>
+Bug: https://bugs.debian.org/890446
+Bug-Ubuntu: https://launchpad.net/bugs/1861941
+Forwarded: https://github.com/koverstreet/bcache-tools/pull/6/
+Reviewed-By: Rafael David Tinoco <[e-mail]>
+Last-Update: 2020-07-22
+
+--- bcache-tools-1.0.8.orig/69-bcache.rules
++++ bcache-tools-1.0.8/69-bcache.rules
+@@ -23,10 +23,9 @@ RUN+="bcache-register $tempnode"
+ LABEL="bcache_backing_end"
+ 
+ # Cached devices: symlink
+-DRIVER=="bcache", ENV{CACHED_UUID}=="?*", \
+-        SYMLINK+="bcache/by-uuid/$env{CACHED_UUID}"
+-DRIVER=="bcache", ENV{CACHED_LABEL}=="?*", \
+-        SYMLINK+="bcache/by-label/$env{CACHED_LABEL}"
++IMPORT{program}="bcache-export-cached $tempnode"
++ENV{CACHED_UUID}=="?*", SYMLINK+="bcache/by-uuid/$env{CACHED_UUID}"
++ENV{CACHED_LABEL}=="?*", SYMLINK+="bcache/by-label/$env{CACHED_LABEL}"
+ 
+ LABEL="bcache_end"
+ 
+--- bcache-tools-1.0.8.orig/Makefile
++++ bcache-tools-1.0.8/Makefile
+@@ -9,7 +9,7 @@ all: make-bcache probe-bcache bcache-sup
+ 
+ install: make-bcache probe-bcache bcache-super-show
+ 	$(INSTALL) -m0755 make-bcache bcache-super-show	$(DESTDIR)${PREFIX}/sbin/
+-	$(INSTALL) -m0755 probe-bcache bcache-register		$(DESTDIR)$(UDEVLIBDIR)/
++	$(INSTALL) -m0755 probe-bcache bcache-register bcache-export-cached $(DESTDIR)$(UDEVLIBDIR)/
+ 	$(INSTALL) -m0644 69-bcache.rules	$(DESTDIR)$(UDEVLIBDIR)/rules.d/
+ 	$(INSTALL) -m0644 -- *.8 $(DESTDIR)${PREFIX}/share/man/man8/
+ 	$(INSTALL) -D -m0755 initramfs/hook	$(DESTDIR)/usr/share/initramfs-tools/hooks/bcache
+--- /dev/null
++++ bcache-tools-1.0.8/bcache-export-cached
+@@ -0,0 +1,31 @@
++#!/bin/sh
++#
++# This program reads the bcache superblock on bcacheX slaves to extract the
++# dev.uuid and dev.label which refer to a specific backing device.
++#
++# It integrates with udev 'import' by writing CACHED_UUID=X and optionally
++# CACHED_LABEL=X for the backing device of the provided bcache device.
++# Ignore caching devices by skipping unless sb.version=1
++#
++# There is 1 and only 1 backing device (slaves/*) for a bcache device.
++
++TEMPNODE=${1}               # /dev/bcacheN
++DEVNAME=${TEMPNODE##*/}     # /dev/bcacheN -> bcacheN
++
++for slave in "/sys/class/block/$DEVNAME/slaves"/*; do
++    [ -d "$slave" ] || continue
++    /usr/sbin/bcache-super-show "/dev/${slave##*/}" |
++       awk '$1 == "sb.version" { sbver=$2; }
++            $1 == "dev.uuid" { uuid=$2; }
++            $1 == "dev.label" && $2 != "(empty)" { label=$2; }
++            END {
++                if (sbver == 1 && uuid) {
++                    print("CACHED_UUID=" uuid)
++                    if (label) print("CACHED_LABEL=" label)
++                    exit(0)
++                }
++                exit(1);
++            }'
++    # awk exits 0 if it found a backing device.
++    [ $? -eq 0 ] && exit 0
++done
+--- bcache-tools-1.0.8.orig/initcpio/install
++++ bcache-tools-1.0.8/initcpio/install
+@@ -1,6 +1,7 @@
+ #!/bin/bash
+ build() {
+     add_module bcache
++    add_binary /usr/lib/udev/bcache-export-cached
+     add_binary /usr/lib/udev/bcache-register
+     add_binary /usr/lib/udev/probe-bcache
+     add_file /usr/lib/udev/rules.d/69-bcache.rules
+--- bcache-tools-1.0.8.orig/initramfs/hook
++++ bcache-tools-1.0.8/initramfs/hook
+@@ -22,6 +22,7 @@ elif [ -e /lib/udev/rules.d/69-bcache.ru
+     cp -pt "${DESTDIR}/lib/udev/rules.d" /lib/udev/rules.d/69-bcache.rules
+ fi
+ 
++copy_exec /lib/udev/bcache-export-cached
+ copy_exec /lib/udev/bcache-register
+ copy_exec /lib/udev/probe-bcache
+ manual_add_modules bcache
diff --git a/debian/patches/series b/debian/patches/series
index 209d512..2db46fa 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -1,2 +1,3 @@
 0001-Clean-should-remove-bcache-register.patch
 0002-Don-t-inline-crc64-for-gcc-5-compatibility.patch
+0003-Add-bcache-export-cached-helper.patch