Re: [PATCH 1/4] vfs: vfs-level fiemap interface

[Theodore Tso <tytso@mit.edu>]

On Mon, Oct 06, 2008 at 02:15:08PM -0400, jim owens wrote:
>> +
>> +Currently, there are three flags which can be set in fm_flags:
>
> Current flags which can be set in fm_flags:
>

Good catch, thanks.

> And a documentation issue with this new change:
>
>> +
>> +* FIEMAP_EXTENT_NO_MOUNTED_IO
>
> Did you really intend to name it FIEMAP_EXTENT_NO_MOUNTED_IO
> or did you intend it to be FIEMAP_EXTENT_NO_UNMOUNTED_IO ?

The latter; thanks for catching that 

> FIEMAP interface is never guaranteed to be consistent and should
> not be attempted by user applications.
>
> [ IMO - it is confusing to say "undefined" when the flag is ]
> [       set and also say "undefined" when the flag is clear ]
>

Yeah.  Is this better?

+* FIEMAP_EXTENT_NO_UNMOUNTED_IO
+Accessing the data in this extent via I/O to the block device while the
+filesystem is unmounted is illegal or will have undefined results.  This
+may be because the data is somehow encrypted or compressed by the filesystem.
+Note that accessing the data using the information returned by the
+FIEMAP interface while the filesystem is mounted is *always* undefined
+should not be attempted by user applications. 

							- Ted