Potential improvements to the handling of shares on mount points

[database64128]

Currently, ksmbd's handling of shares on mount points has some rough edges:

1. If a share path becomes a mount point after the ksmbd service starts, the share exhibits abnormal behavior. The root directory is visible, but files cannot be opened, subdirectories cannot be entered, and while new empty files can be created, they cannot be modified or deleted. Restarting the ksmbd service resolves this.
2. If a share path is a mount point when the service starts, unmounting always returns -EBUSY.

Ideally, in the first scenario, the share should either appear empty or function correctly. The current behavior is misleading, especially if the mount point was temporarily unavailable due to required manual intervention like running fsck.

For the second scenario, it'd be nice if the share can be successfully unmounted.

[namjaejeon]

If a share path becomes a mount point after the ksmbd service starts, the share exhibits abnormal behavior. The root directory is visible, but files cannot be opened, subdirectories cannot be entered, and while new empty files can be created, they cannot be modified or deleted. Restarting the ksmbd service resolves this.

Can you explain how to reproduce ? Shouldn't there be a share directory initially?

If a share path is a mount point when the service starts, unmounting always returns -EBUSY.

Do you want the command for "ksmbd server pause" to umount share directory ? and "ksmbd server resume" command will reopen share directory and restart file sharing.

[database64128]

Apologies for the delay.

Can you explain how to reproduce ? Shouldn't there be a share directory initially?

Yes, the share directory is there when ksmbd is started. It is empty though because nothing is mounted yet. Let's say we start ksmbd with the following share:

[external]
    path = /mnt/external

Then we mount something to /mnt/external:

mount /dev/sdb1 /mnt/external

Now visit the external share. Files and directories in the root directory are visible, but you cannot access them. You can create new empty files, but they cannot be modified or deleted. Restarting ksmbd fixes it.

Do you want the command for "ksmbd server pause" to umount share directory ? and "ksmbd server resume" command will reopen share directory and restart file sharing.

I'm not sure if the commands would help. Because ksmbd does not show up in lsof, it's hard for the user to realize that ksmbd is the cause of -EBUSY.

Ideally, unmounting should just succeed. But this does sound like something difficult or just too messy to be implemented properly.