Jiaying Zhang wrote: > On Tue, Sep 29, 2009 at 12:15 PM, Eric Sandeen <sandeen@xxxxxxxxxx> wrote: >> Jiaying Zhang wrote: >>> Sorry for taking so long to finish this. Here is the new patch based on >>> Andreas's suggestions. Now the patch clears the EXT4_EOFBLOCKS_FL >>> flag when we allocate beyond the maximum allocated block. I also >>> made the EOFBLOCKS flag user visible and added the handling >>> in ext4_ioctl as Andrea suggested. >> I was testing this a bit in xfstests, with test 083 (recently I sent a >> patch to the xfs list to let that test run on generic filesystems) which >> runs fsstress on a small-ish 100M fs, and that fsstress does space >> preallocation (on newer kernels, where the older xfs ioctls are hooked >> up to do_fallocate in a generic fashion). > > Does the fsstress use fallocate with KEEP_SIZE? Effectively, yes. It uses the compatible xfs ioctls, which calls do_fallocate with KEEP_SIZE. >> I'm actually seeing more corruption w/ this patch than without it, >> though I don't yet see why. I'll double check that it applied properly, >> since this was against 2.6.30.5.... > > Do you want me to port my changes to the latest ext4 git tree? > I should have done so at the beginning. Sure :) >> Also it strikes me as a little odd to allow clearing of the EOF Flag >> from userspace, and the subsequent discarding of the blocks past EOF. >> >> Doesn't truncating to i_size do exactly the same thing, in a more >> portable way? Why make a new interface unique to ext4? > > As Andreas suggested, I think the main purpose is to allow users > to scan for any files with EOF flag with the getflag ioctl. We may > not allow users to clear it with the setflag ioctl but just rely on > the truncate interface, but supporting the setflag ioctl interface > doesn't seem to do any harm. I like the idea of being able to find them, but adding the clearing interface seems redundant to me. All filesystems would need to implement this, and I don't see that we gain anything. Thanks, -Eric > Jiaying -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
