Public bug reported: [Impact]
After including the patch from bug 1642903, NVMe devices that include spaces in their model or serial strings result in incorrect symlinks, e.g. if the model string is "XYZ Corp NVMe drive" then instead of creating: /dev/disk/by-id/nvme-XYZ Corp NVMe drive_SERIAL -> ../../nvme0n1 it creates: /dev/disk/by-id/nvme-XYZ -> ../../nvme0n1 /dev/Corp -> nvme0n1 /dev/NVMe -> nvme0n1 /dev/drive_SERIAL -> nvme0n1 This is because of the way udev handles the SYMLINK value strings; by default, it does not do any whitespace replacement. To enable whitespace replacement of a symlink value, the rule must also include OPTIONS+="string_escape=replace". This is done for 'md' and 'dm' devices in their rules. However, there are no rules that actually want to specify multiple symlinks, and defaulting to not replacing whitespace makes no sense; instead, the default should be to replace all whitespace in each symlink value, unless the rule explicitly specifies OPTIONS+="string_escape=none". [Test Case] This assumes using udev with the patch from bug 1642903. Without this patch, when using a NVMe drive that contains spaces in its model and/or serial strings, check the /dev/disk/by-id/ directory. It should contain a partially-correct symlink to the NVMe drive, with the name up to the first space. All following space-separated parts of the mode/serial string should have symlinks in the /dev/ directory. This is the incorrect behavior. With this patch, check the /dev/disk/by-id/ directory. It should contain a fully-correct symlink to the NVMe drive, and no part of the drive's model/serial number string should be a link in the /dev directory. An example of the correct/incorrect naming is in the Impact section. There should be no other changes to any of the symlinks under /dev before and after this patch. Typical locations for symlinks are /dev/, /dev/disk/by-name/, /dev/disk/by-id/, /dev/disk/by-uuid/, /dev/disk/by- label/ [Regression Potential] Errors in udev rules can lead to an unbootable or otherwise completely broken system if they unintentionally break or clobber existing /dev/disks/ symlinks. [Other Info] This is also tracked with upstream systemd (udev) bug 4833: https://github.com/systemd/systemd/issues/4833 Also note, this can be worked around ONLY for NVMe devices by adding OPTIONS+="string_escape=none" to each of the NVMe SYMLINK+="..." rules at the end, e.g.: KERNEL=="nvme*[0-9]n*[0-9]", ENV{DEVTYPE}=="disk", ATTRS{model}=="?*", ENV{ID_SERIAL_SHORT}=="?*", ENV{ID_SERIAL}="$attr{model}_$env{ID_SERIAL_SHORT}", SYMLINK+="disk/by- id/nvme-$env{ID_SERIAL}", OPTIONS+="string_escape=none" ** Affects: systemd (Ubuntu) Importance: Undecided Status: New ** Description changed: [Impact] After including the patch from bug 1642903, NVMe devices that include spaces in their model or serial strings result in incorrect symlinks, e.g. if the model string is "XYZ Corp NVMe drive" then instead of creating: /dev/disk/by-id/nvme-XYZ Corp NVMe drive_SERIAL -> ../../nvme0n1 it creates: /dev/disk/by-id/nvme-XYZ -> ../../nvme0n1 /dev/Corp -> nvme0n1 /dev/NVMe -> nvme0n1 /dev/drive_SERIAL -> nvme0n1 This is because of the way udev handles the SYMLINK value strings; by default, it does not do any whitespace replacement. To enable whitespace replacement of a symlink value, the rule must also include OPTIONS+="string_escape=replace". This is done for 'md' and 'dm' devices in their rules. However, there are no rules that actually want to specify multiple symlinks, and defaulting to not replacing whitespace makes no sense; instead, the default should be to replace all whitespace in each symlink value, unless the rule explicitly specifies OPTIONS+="string_escape=none". [Test Case] This assumes using udev with the patch from bug 1642903. Without this patch, when using a NVMe drive that contains spaces in its model and/or serial strings, check the /dev/disk/by-id/ directory. It should contain a partially-correct symlink to the NVMe drive, with the name up to the first space. All following space-separated parts of the mode/serial string should have symlinks in the /dev/ directory. This is the incorrect behavior. With this patch, check the /dev/disk/by-id/ directory. It should contain a fully-correct symlink to the NVMe drive, and no part of the drive's model/serial number string should be a link in the /dev directory. An example of the correct/incorrect naming is in the Impact section. There should be no other changes to any of the symlinks under /dev before and after this patch. Typical locations for symlinks are /dev/, /dev/disk/by-name/, /dev/disk/by-id/, /dev/disk/by-uuid/, /dev/disk/by- label/ [Regression Potential] Errors in udev rules can lead to an unbootable or otherwise completely broken system if they unintentionally break or clobber existing /dev/disks/ symlinks. [Other Info] This is also tracked with upstream systemd (udev) bug 4833: https://github.com/systemd/systemd/issues/4833 + + Also note, this can be worked around ONLY for NVMe devices by adding + OPTIONS+="string_escape=none" to each of the NVMe SYMLINK+="..." rules + at the end, e.g.: + + KERNEL=="nvme*[0-9]n*[0-9]", ENV{DEVTYPE}=="disk", ATTRS{model}=="?*", + ENV{ID_SERIAL_SHORT}=="?*", + ENV{ID_SERIAL}="$attr{model}_$env{ID_SERIAL_SHORT}", SYMLINK+="disk/by- + id/nvme-$env{ID_SERIAL}", OPTIONS+="string_escape=none" -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1647485 Title: NVMe symlinks broken by devices with spaces in model or serial strings To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1647485/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
