Re: [ECOS] JFFS2 fseek

[Andrew Lunn <andrew at lunn dot ch>]

> There looks to be a logic bug...
> 
>     Cyg_ErrNo err;
>     off_t newpos=pos;
>  
>     err = cyg_stdio_lseek( my_device, &newpos, whence );
>  
>     if( err == ENOERR )
>     {
>         // Clean out the buffer. Flush output if any present,
>         // and clear any input out of input buffer and any ungot
>         // chars from unread buffer.
>                                                                                                              
>         err = flush_output_unlocked();
>         io_buf.drain_buffer();
> 
> It appears to be working out where the new position is and then
> seeking the file descriptor to the new position. It then flushed the
> stream write buffer and resets the input buffer. 
> 
> To me, this seems to be in the wrong order. It should flush the
> buffers before moving the file pointer. Attached is a totally untested
> patch. It might work. Please give it a try and let me know.
> 
>        Andrew

I've tested this patch now and it appears to work OK for the simple
case i've tested. I've added a new test to the ramfs code which
exercises fseek and ftell a little.

          Andrew

Attachment: fseek.patch
Description: Text document