Mounting cifs drive with snapshot option gives: "cifs: Bad value for 'snapshot'"

robot40q

6/9/23, 7:48 PM

I have File share in Azure and I want to mount one of its snapshots. I am using following command:

sudo /bin/mount -t cifs //storageAccountName.file.core.windows.net/fileShareName /home/userName/mount -o vers=3.0,credentials=/home/userName/cred,dir_mode=0444,file_mode=0444,serverino,snapshot=132888855100000000

and it fails with

mount error(22): Invalid argument
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs) and kernel log messages (dmesg)

I can get slightly more info with sudo tail -f /var/log/kern.log

Feb  9 18:16:58 VmName kernel: [ 3963.812792] cifs: Bad value for 'snapshot'

If I don't use the snapshot option then everythig works as expected (but then I have current File share not snapshot)

sudo /bin/mount -t cifs //storageAccountName.file.core.windows.net/fileShareName /home/userName/mount -o vers=3.0,credentials=/home/userName/cred,dir_mode=0444,file_mode=0444,serverino

I use Ubuntu 20.04* in Azure, the strange thing is that in Ubuntu 18.04** it works just fine! Unfortunately I am forced to use 20.04.

*Ubuntu 20.04:

>hostnamectl
         Icon name: computer-vm
           Chassis: vm
    Virtualization: microsoft
  Operating System: Ubuntu 20.04.3 LTS
            Kernel: Linux 5.11.0-1028-azure
      Architecture: x86-64

>apt list --installed | grep cifs
cifs-utils/focal-updates,now 2:6.9-1ubuntu0.1 amd64 [installed]

**Ubuntu 18.04:

>hostnamectl
         Icon name: computer-vm
           Chassis: vm
    Virtualization: microsoft
  Operating System: Ubuntu 18.04.6 LTS
            Kernel: Linux 5.4.0-1067-azure
      Architecture: x86-64

>apt list --installed | grep cifs
cifs-utils/bionic-updates,now 2:6.8-1ubuntu1.1 amd64 [installed]

I was even able to update cifs-utils in Ubuntu 18.04 to version 6.9 (the same as in 20.04) and it still worked just fine so I don't think cifs-utils is the problem.

Any help appreciated.

0 + 0

mount

cifs

azure

20.04

Score:0

Ubuntu

robot40q

6/11/23, 5:05 PM

It is Linux kernel regression (introduced in v5.11). They added some additional checks (in commit "24e0a1eff9e2b9835a6e7c17039dfb6ecfd81f1f"). One of them is checking that snapshot value is 32 unsigned integer. Trouble is this value is supposed to be 64 unsigned integer. Hence the wrong check resulted in "bad value" error message and fail of mount.

For details see their bugtracker: https://bugzilla.kernel.org/show_bug.cgi?id=215593

0 + 0

robot40q

6/11/23, 5:09 PM

Will accept when the issue in kernel is confirmed.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Mounting cifs drive with snapshot option gives: "cifs: Bad value for 'snapshot'"

TH: การเมานต์ไดรฟ์ cifs พร้อมตัวเลือกสแน็ปช็อตให้: "cifs: ค่าที่ไม่ถูกต้องสำหรับ 'สแน็ปช็อต'"

RO: Montarea unității CIF cu opțiunea de instantaneu oferă: „cifs: Valoare greșită pentru „snapshot””

RU: Монтирование диска cifs с опцией моментального снимка дает: «cifs: неправильное значение для« моментального снимка »»

VI: Gắn ổ đĩa cifs với tùy chọn ảnh chụp nhanh mang lại: "cifs: Giá trị không hợp lệ cho 'ảnh chụp nhanh'"

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