Re: Receive available and used space from JFFS2

[Savin Zlobec <savin at elatec dot si>]

Andrew Lunn wrote:

> > I've noticed that you used a 32 bit value for returning fs space info, 
> > this may
> > not be such an good idea - check an old discussion about this at
> > http://ecos.sourceware.org/ml/ecos-devel/2003-07/msg00031.html .
> > I think a better way would be to return a structure with free/used space
> > in blocks + block size.
> >    
>
> You are assuming a block based storage media. romfs does not have
> blocks. Although jffs2 uses flash blocks, the files themselves are not
> block based. Only ramfs and fat use blocks.
>
> I think i might change the interface to pass a cyg_uint64 instead.
>
>  
On a non block based fs block size could be just set to 1.

> > It would also be nice to put the keys (+ common structures)
> > in a separate file - like it is done with IO config_keys.h.
> >    
>
> Humm. I think Nick put the origional 3 keys in fileio.h. He should
> decide if they should be moved out to a seperate header file.
>  
There is a lot of operations on a fs which can be covered with this 
interface -
some are general like the free/used sizes and the odher are fs dependent 
- like
set/get volume label, reserved blocks access ...

I don't like putting all of the keys and accompanying structures in 
fileio.h.
I would propose a separate file which could hold general keys and specific
fs keys offsets like:

#define FS_INFO_CONF           1
#define FS_INFO_ACCESS      2
#define FS_INFO_GETCWD    3
#define FS_INFO_FREESIZE   4
#define FS_INFO_USEDSIZE  5

#define FS_INFO_ROMFS_KEYS_START 0x100
#define FS_INFO_RAMFS_KEYS_START 0x200
#define FS_INFO_JFFS2_KEYS_START     0x300
#define FS_INFO_FATFS_KEYS_START   0x400

This way all of the fs specific data would go into fs specific header files.


savin