ncpfs quirks

PWF Linux uses a modified version of the Linux NCP file system (ncpfs) for mounting home directories. This version of ncpfs is set up to provide something closer to Unix file-system semantics than the standard one, but it still differs in the following ways:

File Names

File names are encoded in UTF-8, but may only use characters in IBM code page 850. In addition, the following characters are not usable in file names. and will be converted to "_" (U+005F) when an object is created:

All other characters should work correctly.

Long file names

File names longer than 127 characters cannot be created. System calls which attempt to create them will return ENAMETOOLONG.

Hard Links

Hard links are faked on the client side. They only exist in the memory of an individual client, and are never created on the server. Renaming through hard links does work, however.

Ownership

All objects appear to be owned by the logged-in user. chown(2) returns EPERM.

Permissions

Unix permissions set by chmod(2) appear correctly to stat(2), but only execute permissions are honoured by the kernel. All other permission checking is handled by NetWare. Files with none of the "write" bits set get flagged as NetWare "read-only".

Unlinked files

Once a file has been unlinked, read(2) and write(2) operations on it fail with EPERM.

Device nodes

While it's possible to create device nodes, they don't retain major and minor number information, so they're of little use. Users can't create them anyway.

Quotas

Exceeding quota generates EIO rather than EDQUOT. There is no easy way to find out a user's remaining quota.

File time stamps

When summer time is in effect, file time stamps referring to times not in summer time will be incorrect by one hour, and vice versa.

File attributes

The NetWare read-only flag on a file or directory is presented as the "immutable" flag through lsattr(1), and can be changed using chattr(1). Changing this flag will cause the delete-inhibit and rename-inhibit flags to be changed to match.