On 4/14/19 6:02 PM, NeilBrown wrote:
> On Sun, Apr 14 2019, Jes Sorensen wrote:
>
>> On 3/25/19 7:24 PM, NeilBrown wrote:
>>> On Mon, Mar 25 2019, Liwei Song wrote:
>>>
>>>> On 03/25/2019 07:43 AM, NeilBrown wrote:
>>>>> On Tue, Mar 19 2019, Liwei Song wrote:
>>>>>
>>>>>> This rules will create link under /dev/disk/by-partuuid/ for
>>>>>> MD devices partition, with which will support specify
>>>>>> root=PARTUUID=XXX to boot rootfs.
>>>>>>
>>>>>> Signed-off-by: Liwei Song <liwei.song@xxxxxxxxxxxxx>
>>>>>> ---
>>>>>> udev-md-raid-arrays.rules | 1 +
>>>>>> 1 file changed, 1 insertion(+)
>>>>>>
>>>>>> diff --git a/udev-md-raid-arrays.rules b/udev-md-raid-arrays.rules
>>>>>> index c95ec7b1e4a9..5b99d5873ade 100644
>>>>>> --- a/udev-md-raid-arrays.rules
>>>>>> +++ b/udev-md-raid-arrays.rules
>>>>>> @@ -30,6 +30,7 @@ IMPORT{builtin}="blkid"
>>>>>> OPTIONS+="link_priority=100"
>>>>>> OPTIONS+="watch"
>>>>>> ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{ID_FS_UUID_ENC}=="?*", SYMLINK+="disk/by-uuid/$env{ID_FS_UUID_ENC}"
>>>>>> +ENV{ID_FS_USAGE}=="filesystem|other", ENV{ID_PART_ENTRY_UUID}=="?*", SYMLINK+="disk/by-partuuid/$env{ID_PART_ENTRY_UUID}"
>>>>>> ENV{ID_FS_USAGE}=="filesystem|other", ENV{ID_FS_LABEL_ENC}=="?*", SYMLINK+="disk/by-label/$env{ID_FS_LABEL_ENC}"
>>>>>>
>>>>>> ENV{MD_LEVEL}=="raid[1-9]*", ENV{SYSTEMD_WANTS}+="mdmonitor.service"
>>>>>> --
>>>>>> 2.7.4
>>>>>
>>>>> This doesn't make any sense to me.
>>>>> Presumably you want the by-partuuid link to point to a partition in the
>>>>> array?
>>>>
>>>> Yes, That is what I want.
>>>>
>>>>> But this code will create a link pointing to the array.
>>>>
>>>> Because there is no ID_PART_ENTRY_UUID for the array, only partition in the array have
>>>> such attribute，So in my case it will only create by-partuuid for a partition.
>>>>
>>>> For example, there is an md126 raid array,
>>>>
>>>> Disk /dev/md126: 44.2 GiB, 47501541376 bytes, 92776448 sectors
>>>> Units: sectors of 1 * 512 = 512 bytes
>>>> Sector size (logical/physical): 512 bytes / 512 bytes
>>>> I/O size (minimum/optimal): 512 bytes / 512 bytes
>>>> Disklabel type: gpt
>>>> Disk identifier: 622CA1DE-A938-4704-98B0-5EAB0D3A7AAC
>>>>
>>>> Device Start End Sectors Size Type
>>>> /dev/md126p1 2048 2000895 1998848 976M EFI System
>>>> /dev/md126p2 2000896 88138671 86137776 41.1G Linux filesystem
>>>> /dev/md126p3 88138672 92776414 4637743 2.2G Linux swap
>>>>
>>>>
>>>>
>>>> # udevadm info /dev/md126 |grep ID_PART_ENTRY_UUID
>>>> this will get nothing since array do not have ID_PART_ENTRY_UUID.
>>>>
>>>> # udevadm info /dev/md126p1 |grep ID_PART_ENTRY_UUID
>>>> E: ID_PART_ENTRY_UUID=018496b3-84e1-4c9f-864e-81650b21402f
>>>> # udevadm info /dev/md126p2 |grep ID_PART_ENTRY_UUID
>>>> E: ID_PART_ENTRY_UUID=2c1df1c5-41c8-42b4-a874-95dbf07820d5
>>>> # udevadm info /dev/md126p3 |grep ID_PART_ENTRY_UUID
>>>> E: ID_PART_ENTRY_UUID=bccde74f-efee-4b99-860c-998493d549a9
>>>>
>>>> it will create by-partuuid under /dev/disk/ for the partition in array
>>>>
>>>> # ls /dev/disk/by-partuuid/ -all
>>>> lrwxrwxrwx 1 root root 13 Mar 22 03:33 018496b3-84e1-4c9f-864e-81650b21402f -> ../../md126p1
>>>> lrwxrwxrwx 1 root root 13 Mar 22 03:33 2c1df1c5-41c8-42b4-a874-95dbf07820d5 -> ../../md126p2
>>>> lrwxrwxrwx 1 root root 13 Mar 22 03:33 bccde74f-efee-4b99-860c-998493d549a9 -> ../../md126p3
>>>>
>>>> if my rootfs store in /dev/md126p2, then I can specify root=PARTUUID=2c1df1c5-41c8-42b4-a874-95dbf07820d5
>>>> through command line to boot it.
>>>>
>>>
>>> Thanks.
>>> I was thinking that udev-md-raid-arrays.rule only dealt with the whole
>>> array and that other files like 60-persistent-storage.rules dealt
>>> with parititons, but I was wrong.
>>> 60-persistent-storage.rules has
>>> KERNEL!="loop*|mmcblk*[0-9]|msblk*[0-9]|mspblk*[0-9]|nvme*|sd*|sr*|vd*|xvd*|bcache*|cciss*|dasd*|ubd*|scm*|pmem*|nb>
>>>
>>> so it doesn't touch md array. And udev-md-raid-arrays.rules already has
>>>
>>> ENV{DEVTYPE}=="partition", ENV{MD_NAME}=="?*", SYMLINK+="disk/by-id/md-name-$env{MD_NAME}-part%n", OPTIONS+="string_escape=replace"
>>> ENV{DEVTYPE}=="partition", ENV{MD_UUID}=="?*", SYMLINK+="disk/by-id/md-uuid-$env{MD_UUID}-part%n"
>>> ENV{DEVTYPE}=="partition", ENV{MD_DEVNAME}=="*[^0-9]", SYMLINK+="md/$env{MD_DEVNAME}%n"
>>> ENV{DEVTYPE}=="partition", ENV{MD_DEVNAME}=="*[0-9]", SYMLINK+="md/$env{MD_DEVNAME}p%n"
>>>
>>> so it does handle partitions of md array.
>>>
>>> So yes, your patch does make sense.
>>>
>>> Reviewed-by: NeilBrown <neilb@xxxxxxxx>
>>
>> Trying to catch up here, so the conclusion was the original patch was
>> good, correct?
>
> Correct!
Great, applied!
Thanks,
Jes
