> Hi! > > On Mon, Oct 03, 2011 at 04:54:29AM +0000, YAMAMOTO Takashi wrote: >> > The new implementation presents the default one-blob for file systems that >> > don't implement it. For NetBSD its currently implemented for UFS and is >> > tested for FFS with/without WAPBL, ext2fs and lfs. It is present in our >> > ZFS import but aparently disabled still and i dont have a ZFS partition to >> > play with. I might be tempted to try it later on my scratch machine :) UDF >> > is next but shouldn't be that difficult. >> >> why is the VOP_FSYNC call necessary? > > The sparse region search code depends on the indirect blocks being correctly > written out as it traverses them. If the file is still `dirty' all the > indirect blocks are present as negative indices so the normal FFS code works > but their indirect blocks, when addressed with their disc addresses, are not > up-to-date. > > The FFS sparse region search code depends on the indirect blocks to see where > actual data is recorded and needs the indirect blocks to be up-to-date. A > range sync with only the negative range might also suffice but since most if > not all of the applications of this code is dealing with backup/processing the > VOP_FSYNC() is normally a NOP. > > I hope this explanation helps :)
what's wrong with just reporting dirty regions as non-hole? YAMAMOTO Takashi > > With regards, > Reinoud
