From 35807e8f634ce86bc77b3461cb0deb466c08a9d2 Mon Sep 17 00:00:00 2001 From: Trevor Woerner Date: Mon, 14 Apr 2025 22:04:05 -0400 Subject: [PATCH] wic: do not ignore ROOTFS_SIZE if the rootfs is modified If the *.wks file contains a "--source rootfs" then lib/wic/plugins/source/rootfs.py will be invoked to generate (what is assumed to be) the rootfs partition. If the rootfs partition needs to be tweaked or modified, the "rootfs.py" plugin will make a copy of the filesystem and then perform the changes on that copy. In other words, if the "--source rootfs" line of the *.wks file also contains any of: --exclude-path --include-path --change-directory --use-label (i.e. modify etc/fstab) then the rootfs will be copied first, then the copy is modified. If, for example, the unmodified IMAGE_ROOTFS is: .../tmp/work/qemuarm64_secureboot-oe-linux/core-image-base/1.0/rootfs then the copy would be made at: .../tmp/work/qemuarm64_secureboot-oe-linux/core-image-base/1.0/tmp-wic/rootfs${LINENO} where ${LINENO} is the line number where this "--source rootfs" line appears in the *wks file. When it comes time to make an actual partition of a specific filesystem type, lib/wic/partition.py::prepare_rootfs() is called. It is in this function that wic figures out if any extra size needs to be added. The bitbake variable used to specify the ultimate rootfs size is ROOTFS_SIZE, and since this variable is only valid for the rootfs (and not any other partitions), the code also verifies that the partition being created is ${IMAGE_ROOTFS}: rsize_bb = get_bitbake_var('ROOTFS_SIZE') rdir = get_bitbake_var('IMAGE_ROOTFS') if rsize_bb and rdir == rootfs_dir: else: As noted above, if lib/wic/plugins/source/rootfs.py has made a copy, then the "rdir == rootfs_dir" clause will fail and the code will assume this partition is not a rootfs since the strings do not compare equal. Therefore, in order to determine if this is a rootfs, retain the existing "rdir == rootfs_dir" comparison, but also add another one to check whether or not this is a wic-generated copy of the rootfs. STEPS TO REPRODUCE: - start with the following *wks file: bootloader --ptable gpt part /boot --size=100M --active --fstype=ext4 --label boot part / --source rootfs --fstype=ext4 --label root - and the following extra variable in conf/local.conf: IMAGE_ROOTFS_EXTRA_SPACE = "500000" - build an image - run it in qemu $ runqemu slirp nographic serial - verify the root partition has extra space: root@qemuarm64-secureboot:~# df -h Filesystem Size Used Available Use% Mounted on /dev/root 721.5M 67.4M 600.6M 10% / devtmpfs 477.7M 0 477.7M 0% /dev tmpfs 40.0K 0 40.0K 0% /mnt tmpfs 489.3M 92.0K 489.2M 0% /run tmpfs 489.3M 68.0K 489.2M 0% /var/volatile /dev/vda1 120.4M 19.9M 91.4M 18% /boot - modify the "/" line of the *wks file to be: part / --source rootfs --fstype=ext4 --label root --exclude-path boot/ - build image when it fails: root@qemuarm64-secureboot:~# df -h Filesystem Size Used Available Use% Mounted on /dev/root 73.4M 41.9M 25.8M 62% / devtmpfs 477.7M 0 477.7M 0% /dev tmpfs 40.0K 0 40.0K 0% /mnt tmpfs 489.3M 92.0K 489.2M 0% /run tmpfs 489.3M 68.0K 489.2M 0% /var/volatile /dev/vda1 120.4M 19.9M 91.4M 18% /boot after this fix: root@qemuarm64-secureboot:~# df -h Filesystem Size Used Available Use% Mounted on /dev/root 721.5M 47.4M 620.6M 7% / devtmpfs 477.7M 0 477.7M 0% /dev tmpfs 40.0K 0 40.0K 0% /mnt tmpfs 489.3M 92.0K 489.2M 0% /run tmpfs 489.3M 68.0K 489.2M 0% /var/volatile /dev/vda1 120.4M 19.9M 91.4M 18% /boot Doing the math we see that the /boot partition is ~20MB and in the first image the / partition contains this ~20MB in addition to the rest of the rootfs. This ~20MB is completely wasted since it is used in the / partition, but then the /boot partition is mounted on top of it, making the /boot directory of / inaccessible. After the fix the / partition has an additional ~20MB since the /boot portion is excluded. Fixes [YOCTO #15555] (From OE-Core rev: 1c690aa046ebca13d7b29de50d42b5d8a4a8486c) Signed-off-by: Trevor Woerner Signed-off-by: Richard Purdie --- meta/lib/oeqa/selftest/cases/wic.py | 33 +++++++++++++++++++++++++++++ scripts/lib/wic/partition.py | 2 +- 2 files changed, 34 insertions(+), 1 deletion(-) diff --git a/meta/lib/oeqa/selftest/cases/wic.py b/meta/lib/oeqa/selftest/cases/wic.py index 59fd99a788..d98af8713a 100644 --- a/meta/lib/oeqa/selftest/cases/wic.py +++ b/meta/lib/oeqa/selftest/cases/wic.py @@ -535,6 +535,39 @@ part /mnt --source rootfs --ondisk mmcblk0 --fstype=ext4 --exclude-path bin/whoa finally: os.environ['PATH'] = oldpath + def test_exclude_path_with_extra_space(self): + """Test having --exclude-path with IMAGE_ROOTFS_EXTRA_SPACE. [Yocto #15555]""" + + with NamedTemporaryFile("w", suffix=".wks") as wks: + wks.writelines( + ['bootloader --ptable gpt\n', + 'part /boot --size=100M --active --fstype=ext4 --label boot\n', + 'part / --source rootfs --fstype=ext4 --label root --exclude-path boot/\n']) + wks.flush() + config = 'IMAGE_ROOTFS_EXTRA_SPACE = "500000"\n'\ + 'DEPENDS:pn-core-image-minimal += "wic-tools"\n'\ + 'IMAGE_FSTYPES += "wic"\n'\ + 'WKS_FILE = "%s"\n' % wks.name + self.append_config(config) + bitbake('core-image-minimal') + + """ + the output of "wic ls .wic" will look something like: + Num Start End Size Fstype + 1 17408 136332287 136314880 ext4 + 2 136332288 171464703 35132416 ext4 + we are looking for the size of partition 2 + i.e. in this case the number 35,132,416 + without the fix the size will be around 85,403,648 + with the fix the size should be around 799,960,064 + """ + bb_vars = get_bb_vars(['DEPLOY_DIR_IMAGE', 'MACHINE'], 'core-image-minimal') + deploy_dir = bb_vars['DEPLOY_DIR_IMAGE'] + machine = bb_vars['MACHINE'] + wicout = glob(os.path.join(deploy_dir, "core-image-minimal-%s.rootfs-*.wic" % machine))[0] + size_of_root_partition = int(runCmd("wic ls %s" % wicout).output.split('\n')[2].split()[3]) + self.assertGreater(size_of_root_partition, 500000000) + def test_include_path(self): """Test --include-path wks option.""" diff --git a/scripts/lib/wic/partition.py b/scripts/lib/wic/partition.py index bf2c34d594..b18431d8fb 100644 --- a/scripts/lib/wic/partition.py +++ b/scripts/lib/wic/partition.py @@ -244,7 +244,7 @@ class Partition(): # from bitbake variable rsize_bb = get_bitbake_var('ROOTFS_SIZE') rdir = get_bitbake_var('IMAGE_ROOTFS') - if rsize_bb and rdir == rootfs_dir: + if rsize_bb and (rdir == rootfs_dir or (rootfs_dir.split('/')[-2] == "tmp-wic" and rootfs_dir.split('/')[-1][:6] == "rootfs")): # Bitbake variable ROOTFS_SIZE is calculated in # Image._get_rootfs_size method from meta/lib/oe/image.py # using IMAGE_ROOTFS_SIZE, IMAGE_ROOTFS_ALIGNMENT,