Umount the device first during mount_usb_storage() (#1587) (BugFix)

[Jefferyyen]

Description

To prevent the inserted storage from failing to mount twice, first ensure it is unmounted.

Because the OS will auto-mount the inserted storage, the existing subprocess.call(["mount", device_to_mount, FOLDER_TO_MOUNT]) command will cause an error if the format of inserted storage is NTFS.

Perform an umount on device_to_mount (e.g., for the media card in #1587, it would be umount /dev/mmcblk0p1) before attempting to mount it again to avoid this issue.

Resolved issues

Fix (#1587)

Documentation

Tests

1. Run checkbox-cli run com.canonical.certification::mediacard/sdhc-storage-manual
2. Insert mediacard as prompt:

--------- Testing insertion ---------


INSERT NOW


Timeout: 30 seconds

3. After detectd the card, checkbox will do the read/write test.

With the above change, it shows:

--------- Testing insertion --------

INSERT NOW


Timeout: 30 seconds
INFO: usable partition: mmcblk0p1
INFO: Device: ultra high speed SDR104 SDHC
INFO: Address: 59b4
INFO: Mediacard insertion test passed.

------- Insertion test passed -------

--------- Testing read/write --------
DEBUG:generating a random file
DEBUG:try to mount usb storage for testing
DEBUG:mount /dev/mmcblk0p1 on /tmp/tmpp76jsgp1 successfully.
DEBUG:===================
DEBUG:writing test begins
DEBUG:===================
DEBUG:Apply command: ['dd', 'if=/tmp/tmphkvvfmg9', 'of=/tmp/tmpp76jsgp1/tmphkvvfmg90', 'bs=1M', 'oflag=sync']
DEBUG:['100+1 records in', '100+1 records out', '104858730 bytes (105 MB, 100 MiB) copied, 7.43403 s, 14.1 MB/s', '']
DEBUG:No I/O errors found in dmesg

Without the change, it shows:

--------- Testing insertion --------

INSERT NOW


Timeout: 30 seconds
INFO: usable partition: mmcblk0p1
INFO: Device: ultra high speed SDR104 SDHC
INFO: Address: 59b4
INFO: Mediacard insertion test passed.

------- Insertion test passed -------

--------- Testing read/write --------
DEBUG:generating a random file
DEBUG:try to mount usb storage for testing
Mount is denied because the NTFS volume is already exclusively opened.
The volume may be already mounted, or another software may use it which
could be identified for example by the help of the 'fuser' command.
ERROR:mount /dev/mmcblk0p1 on /tmp/tmph37fxtlq failed.
INFO:context manager exit: unmount USB storage
umount: /tmp/tmph37fxtlq: not mounted.
WARNING:umount /tmp/tmph37fxtlq failed.
INFO:Remove temporary folders and files.

[fernando79513]

Thanks for the PR. I've just left a small comment there.

[Jefferyyen]

Thanks for making the comments more readable.

[Jefferyyen]

Update the comment.

[Jefferyyen]

@fernando79513 Thank you for the suggestion. Please check if it is okay.

[fernando79513]

I've just seen that the first commit is not signed properly. Please sign the first commit and rebase this branch so all the comments are signed.

[Jefferyyen]

Hi @fernando79513 ,
I have finished signing the 4 commits and push them to the branch. The commits are now signed and verified. Could you please help to review and check if it is fine for merging? Thank you so much once again.