comment #1:
Thank you for your reply.

> * the file name must be meaningfull for humans (what mount is this cache directory for?)

Don't understand why cache files should be "meaningful for humans"? Do you expect the user to go to the cache folder to examine files?

And all other points could be reached with a short hash from this long folder name.

> This results in concatenating resource name, name of the mountpoint and name of the mounting user. If one of these components is missing then duplicates are possible.
> Why don't you use /home/jleman/ plus a hash code of 5 characters?

As mounting folder is accessible by the user and the user is using it to work with files it should be meaningful, as opposed to the cache folder, where only davfs goes.
 

> If the name of your mountpoint really requires to include
> * two times the user name (jleman)
> * three instances of "webdav"

You are right, it's not ideal, just an example. In general, it could be a very long mounting url.

Could you clarify what is the mounting url length limit for davfs on Ubuntu?

In order to mount a webdav recourse a davfs2 trying to create a cache folder for it in a very strange way.

For ex. we mounting:

https://gofast.ceo-vision.com:443/TICKET_XXXREMOVEDFORDEBUGXXXe/alfresco/webdav/Sites/_jlemangarin/

Mounting folder:

/home/jleman/.tmp/webdav/webdavhttps:__gofast.ceo-vision.com:443_TICKET_XXXREMOVEDFORDEBUGXXXe_alfresco_webdav_Sites__jlemangarin_

With this cmd:

pkexec mount -t davfs -o uid=$USER,username=nologin https://gofast.ceo-vision.com:443/TICKET_XXXREMOVEDFORDEBUGXXXe/alfresco/webdav/Sites/_jlemangarin/ /home/jleman/.tmp/webdav/webdavhttps:__gofast.ceo-vision.com:443_TICKET_XXXREMOVEDFORDEBUGXXXe_alfresco_webdav_Sites__jlemangarin_

And got an error:

/sbin/mount.davfs: can't create cache directory /var/cache/davfs2/gofast.ceo-vision.com-TICKET_XXXREMOVEDFORDEBUGXXXe-alfresco-webdav-Sites-_jlemangarin+home-jleman-.tmp-webdav-webdavhttps:__gofast.ceo-vision.com:443_TICKET_XXXREMOVEDFORDEBUGXXXe_alfresco_webdav_Sites__jlemangarin_+jleman

As you could see, davfs creates a very long cache folder name, which exceedes a file system max file name limit 255 chars.

Could you change the way a cache folder name creates by changing it to hash code from this long path? I think 5 chars hash code will be enough.