disk usage cyg_fs_getinfo()

[Andrew Lunn <andrew at lunn dot ch>]

Hi Folks

Attached are four patches which extend the cyg_fs_getinfo call to
retrieve information about the current filesystem disk usage. Using
the key FS_INFO_BLOCK_USAGE you can get the current total number of
blocks in the filesystem, the number of free blocks and the size of a
block. 

With fatfs this is straight forward since there are blocks of fixed
size. With romfs and ramfs the blocks are 1 byte in size. romfs never
has any free blocks, so all you can find out is how big the disk
is. ramfs can be dynamically sized on the heap. In this case the call
is not implemented. When a fixed pool is used the call is implemented.

jffs2 works in terms of flash blocks. 

I have committed romfs, ramfs and fatfs. 

I know Gary is working in updating the jffs2 port to the latest mtd
release in git, so i've not committed this yet. Gary, should i commit?

        Andrew

Attachment: fatfs.diff
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Attachment: ram.diff
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Attachment: rom.diff
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Attachment: jffs2.diff
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