Subject: Re: RFC: VOP_LOOKUP() speedup
To: None <>
From: YAMAMOTO Takashi <>
List: tech-kern
Date: 05/12/2004 07:03:52

> Problem with UDF is that i can't use the device's block cache for CDs/DVDs
> unless i could get it to use it only as a kind of read-`cache' that *never*
> just writes back at its own will if i tell it so. To implement CD-RW and
> DVD-RW, UDFs has to write with a fixed packet length; with CD-R and
> DVD+R/DVD-R its obvious that i can only write in one `direction' i.e.  
> ordered; what happeneds with write-errors i dont even want to know ;) How 
> does the rest of the filingsystems deal with this situation?

i think pinnig buffers (B_LOCKED) is what you want to do.
although you might need to generalize it.  currently it's
very tied to lfs.  i wonder how wasabi people did it for their
journaling filesystem.

depending on how your udf is implemented, it might be easier just to
put a simple hack into VOP_BWRITE.