Re: why does fsync() on a tmpfs directory give EINVAL?

[Chris Friesen <cfriesen@nortel.com>]

Andrew Morton wrote:
> Chris Friesen <cfriesen@nortel.com> wrote:

>>Currently tmpfs reuses the simple_dir_operations from libfs.c.
>>
>>Would it make sense to add the empty fsync() function there, and have 
>>all other users pick it up as well?  Is this likely to break stuff?
>  
> Isn't simple_sync_file() suitable?

I think it would be fine.  The issue is that currently for directories 
tmpfs doesn't have it's own set of operations--it reuses the 
simple_dir_operations set of file ops from libfs.

We could make a tmpfs-specific set of operations that is identical to 
simple_dir_operations but with the addition of setting the fsync 
function to simple_sync_file().

Alternately, if it makes sense for all the users of 
simple_dir_operations we could modify it directly and all of the other 
users of simple_dir_operations would get the change for free.  I don't 
know enough about the other filesystems to know if this makes sense or not.

Chris