freebsd stable - Mar 2006 - Inode Usage

I am building a tool to identify the file that has a specific LBA.   
The approach I am using is to search through each inode from number 2  
up.  This approach works well with UFS1 file systems as then  
preinitialize all the inodes.  However, UFS2 does lazy inode  
initialization so there are always some that are basically garbage.   
I have not found any relaiable way to determine from the inode  
contents if it is in use or not.  I suspect that information is in  
the inode bit map.  However, I haven't found any way to access that.   
Nothing in ffs.h seems to fit the need.  Is there a way to tell if  
inode x is initialized or in use?

At 07:11 PM 3/7/2006, Doug Hardie wrote:
>I am building a tool to identify the file that has a specific LBA.
>The approach I am using is to search through each inode from number 2
>up.  This approach works well with UFS1 file systems as then
>preinitialize all the inodes.  However, UFS2 does lazy inode
>initialization so there are always some that are basically garbage.
>I have not found any relaiable way to determine from the inode
>contents if it is in use or not.  I suspect that information is in
>the inode bit map.  However, I haven't found any way to access that.
>Nothing in ffs.h seems to fit the need.  Is there a way to tell if
>inode x is initialized or in use?
I believe there are macros for that in sys/ufs/ffs/fs.h.
Also, the source for dumpfs probably has good examples of how to use them.

-Glenn
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On Tue, Mar 07, 2006 at 07:11:25PM -0800, Doug Hardie
wrote:
> I am building a tool to identify the file that has a specific LBA.   
> The approach I am using is to search through each inode from number 2  
> up.  This approach works well with UFS1 file systems as then  
> preinitialize all the inodes.  However, UFS2 does lazy inode  
> initialization so there are always some that are basically garbage.   
> I have not found any relaiable way to determine from the inode  
> contents if it is in use or not.  I suspect that information is in  
> the inode bit map.  However, I haven't found any way to access that.   
Have a look at the patch I committed to quot last week:

	http://www.freebsd.org/cgi/cvsweb.cgi/src/usr.sbin/quot/quot.c.diff?r1=1.23&r2=1.24

David.