Specification of the Umsdos file system for LINUX

# Synchronisation problems

[linux/fs/umsdos/namei.c,238]
#Specification: create / file exist in DOS

Here is a situation. Trying to create a file with UMSDOS. The file is unknown to UMSDOS but already exist in the DOS directory.

Here is what we are NOT doing:

We could silently assume that everything is fine and allows the creation to succeed.

It is possible not all files in the partition are mean to be visible from linux. By trying to create those file in some directory, one user may get access to those file without proper permissions. Looks like a security hole to me. Off course sharing a file system with DOS is some kind of security hole :-)

So ?

We return EEXIST in this case. The same is true for directory creation.

[linux/fs/umsdos/namei.c,685]
#Specification: mkdir / Directory already exist in DOS

We do the same thing as for file creation. For all user it is an error.