The next libblkid v2.37 is going to support session offsets for
multi-session CD/DVDs. This feature is implemented by "hint offsets".
These offsets are optional and prober specific (e.g., iso, udf, ...).
For this purpose, the library provides a new function
blkid_probe_set_hint(), and blkid(8) provides a new command-line
option --hint <name>=<offset>. For CD/DVD, the offset name is
"session_offset".
The difference between classic --offset and the new --hint is that
--offset is very restrictive and defines the probing area and the rest
of the device is invisible to the library. The new --hint works
like a suggestion, it provides a hint where the user assumes the
filesystem, but the rest of the device is still readable for the
library (for example, to get some additional superblock information
etc.).
If the --hint is without a value then it defaults to zero.
The option --hint implementation in udev-builtin-blkid.c is backwardly
compatible. If compiled against old libblkid, then the option is used in
the same way as --offset.
Addresses: https://github.com/karelzak/util-linux/issues/1161
Addresses: https://github.com/systemd/systemd/pull/17424
Some cards have names consisting only of whitespace characters which
prevents the original rule from matching and assigning ID_SERIAL
properly. With the split rules ID_SERIAL and ID_NAME are assigned
independently and the symlink is created only if both are available the
same way it has worked for partitions.
ATA devices should use the ATA ids like port number and (possibly)
master/slave or multiplier id, not the generic SCSI ID.
Currently only port number is included in the link. With this patch
the link would be able to support more cases, which are a) when the
device is behind a port multiplexer b) the distinction between master
and slave (distinguished by target id).
I tried to verify scenario a) with this patch, but I failed to find a
machine with PMP SATA devices attached. But the link below
https://github.com/systemd/systemd/issues/3943
could show what's the difference. Here is my test for scenario b)
Current version:
linux-ql21:~ # ll /sys/class/block/sd[ab]
lrwxrwxrwx 1 root root 0 May 8 20:46 /sys/class/block/sda ->
../../devices/pci0000:00/0000:00:01.1/ata4/host3/target3:0:0/3:0:0:0/block/sda
lrwxrwxrwx 1 root root 0 May 8 20:46 /sys/class/block/sdb ->
../../devices/pci0000:00/0000:00:01.1/ata4/host3/target3:0:1/3:0:1:0/block/sdb
linux-ql21:~ # ll /dev/disk/by-path/pci-0000\:00\:01.1-ata-1
lrwxrwxrwx 1 root root 9 May 8 20:44
/dev/disk/by-path/pci-0000:00:01.1-ata-1 -> ../../sdb
linux-ql21:~ # udevadm info /sys/class/block/sda |grep by-path
S: disk/by-path/pci-0000:00:01.1-ata-1
E: DEVLINKS=/dev/disk/by-id/ata-VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-id/scsi-0ATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-id/scsi-1ATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-path/pci-0000:00:01.1-ata-1
/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
linux-ql21:~ # udevadm info /sys/class/block/sdb |grep by-path
S: disk/by-path/pci-0000:00:01.1-ata-1
E: DEVLINKS=/dev/disk/by-id/ata-VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-1ATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-0ATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-path/pci-0000:00:01.1-ata-1
After patch applied:
linux-ql21:~ # ll /sys/class/block/sd[ab]
lrwxrwxrwx 1 root root 0 May 8 21:07 /sys/class/block/sda ->
../../devices/pci0000:00/0000:00:01.1/ata4/host3/target3:0:0/3:0:0:0/block/sda
lrwxrwxrwx 1 root root 0 May 8 21:07 /sys/class/block/sdb ->
../../devices/pci0000:00/0000:00:01.1/ata4/host3/target3:0:1/3:0:1:0/block/sdb
linux-ql21:~ # ll /dev/disk/by-path/pci-0000\:00\:01.1-ata-*
lrwxrwxrwx 1 root root 9 May 8 21:07
/dev/disk/by-path/pci-0000:00:01.1-ata-1.0 -> ../../sda
lrwxrwxrwx 1 root root 9 May 8 21:07
/dev/disk/by-path/pci-0000:00:01.1-ata-1.1 -> ../../sdb
linux-ql21:~ # udevadm info /sys/class/block/sda |grep by-path
S: disk/by-path/pci-0000:00:01.1-ata-1.0
E: DEVLINKS=/dev/disk/by-id/scsi-1ATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-id/scsi-0ATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-id/ata-VBOX_HARDDISK_VB3649e885-3e0cdd64
/dev/disk/by-path/pci-0000:00:01.1-ata-1.0
/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VB3649e885-3e0cdd64
linux-ql21:~ # udevadm info /sys/class/block/sdb |grep by-path
S: disk/by-path/pci-0000:00:01.1-ata-1.1
E: DEVLINKS=/dev/disk/by-id/scsi-0ATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/ata-VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-1ATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-id/scsi-SATA_VBOX_HARDDISK_VBc53b2498-d84ae8de
/dev/disk/by-path/pci-0000:00:01.1-ata-1.1
Changelog:
v5: add another parameter compat_link in handle_scsi()
v4: comment for ID_PATH_ATA_COMPAT
get string length with pointer difference
(suggested by Franck Bui<fbui@suse.com>)
v3: creating compatible link from env
variables type change
v2: remove udev rules modification for compatible link
setup a test scenario of master/slave ATA devices
v1: initial patch
When probing partitions, we inherit important information from the parent
disk device such as ID_MODEL, and usage of such properties is seen to
be acceptable and well established.
However, we need to exclude filesystem information from the properties
that get inherited. Information about the device content should not be
passed on in this way.
For example, Linux distro install media commonly uses an ISO filesystem
plus a partition table. The ISO filesystem is detected on the main disk
device, but we should not pass down those details to the partitions,
some or all of which may be pointing at storage areas completely distinct
from the ISO filesystem.
This is particularly problematic when adding new partitions on media
set up in this way (since the new partitions are then reported to contain
the parent device's ISO filesystem), or when dealing with more unusual
hybrid ISO layouts. The inaccuracy of information here inversely affects
users of blkid and udev's persistent storage symlinks.
Exclude ID_FS_* properties from the inheritance chain to avoid these
problems.
Fixes: #14408
This change is only about the source tree. We have tmpfiles.d/, modprobe.d/,
sysctl.d/, and sysusers.d/, but for historical reasons, rules/ didn't fit this
pattern. We also *install* it as rules.d/. Let's rename to be consistent.
2019-10-10 00:53:09 +01:00
Renamed from rules/60-persistent-storage.rules (Browse further)
