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Date: Thu, 03 Jun 2010 12:32:09 +0400 From: Dmitry Monakhov <dmonakhov@...nvz.org> To: "Aneesh Kumar K. V" <aneesh.kumar@...ux.vnet.ibm.com> Cc: linux-ext4@...r.kernel.org, tytso@....edu Subject: Re: [PATCH] ext4: Do not zeroout uninitialized extents beyond i_size "Aneesh Kumar K. V" <aneesh.kumar@...ux.vnet.ibm.com> writes: > On Wed, 28 Apr 2010 11:38:58 +0400, Dmitry Monakhov <dmonakhov@...nvz.org> wrote: >> "Aneesh Kumar K. V" <aneesh.kumar@...ux.vnet.ibm.com> writes: >> >> > On Fri, 9 Apr 2010 21:22:28 +0400, Dmitry Monakhov <dmonakhov@...nvz.org> wrote: >> >> Zerrout trick allow us to optimize cases where it is more reasonable >> >> to explicitly zeroout extent and mark it as initialized instead of >> >> splitting to several small ones. >> >> But this optimization is not acceptable is extent is beyond i_size >> >> Because it is not possible to have initialized blocks after i_size. >> >> Fsck treat this as incorrect inode size. >> >> >> > >> > With commit c8d46e41bc744c8fa0092112af3942fcd46c8b18 if we set >> > EXT4_EOFBLOCKS_FL we should be able to have blocks beyond i_size. >> > May be the zero out path should set the flag instead of doing all these >> > changes. Zero-out is already complex with all the ENOSPC related >> > consideration. I guess we should try to keep it simple. >> For initialized extent beyond i_size? I've check fsck and seems that >> is truly possible. So this optimization allow us to avoid some >> bad EIO situations. But we have to rework ext_get_blocks( ,create == 1) >> to clear EXT4_EOFBLOCKS_FL if last block of latest_extent is requested. >> I'll handle this. >> > > > > I thought this patch is going to reworked to use EOFBLOCKS_FL. But i see > Ted sent a pull request with the this patch. Did I miss something ? Sorry for a long replay. As far as i can see EXT4_EOFBLOCKS_FL flag is now allowed for uninitialized extents only in e2fslib. So we have to change e2fslib first and then revert the kernel zeroout restriction logic. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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