From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.fusionio.com ([66.114.96.31]:36894 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751669Ab2IJTxT (ORCPT ); Mon, 10 Sep 2012 15:53:19 -0400 Date: Mon, 10 Sep 2012 15:18:03 -0400 From: Josef Bacik To: Liu Bo CC: "linux-btrfs@vger.kernel.org" , Josef Bacik , "dave@jikos.cz" Subject: Re: [PATCH v2 1/6] Btrfs: fix a bug of per-file nocow Message-ID: <20120910191803.GG2270@localhost.localdomain> References: <1347069690-30223-1-git-send-email-bo.li.liu@oracle.com> <1347069690-30223-2-git-send-email-bo.li.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <1347069690-30223-2-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, Sep 07, 2012 at 08:01:25PM -0600, Liu Bo wrote: > Users report a bug, the reproducer is: > $ mkfs.btrfs /dev/loop0 > $ mount /dev/loop0 /mnt/btrfs/ > $ mkdir /mnt/btrfs/dir > $ chattr +C /mnt/btrfs/dir/ > $ dd if=/dev/zero of=/mnt/btrfs/dir/foo bs=4K count=10; > $ lsattr /mnt/btrfs/dir/foo > ---------------C- /mnt/btrfs/dir/foo > $ filefrag /mnt/btrfs/dir/foo > /mnt/btrfs/dir/foo: 1 extent found ---> an extent > $ dd if=/dev/zero of=/mnt/btrfs/dir/foo bs=4K count=1 seek=5 conv=notrunc,nocreat; sync > $ filefrag /mnt/btrfs/dir/foo > /mnt/btrfs/dir/foo: 3 extents found ---> with nocow, btrfs breaks the extent into three parts > > The new created file should not only inherit the NODATACOW flag, but also > honor NODATASUM flag, because we must do COW on a file extent with checksum. > > Signed-off-by: Liu Bo > --- > v1->v2: add check for only regular file > > fs/btrfs/inode.c | 3 +-- > fs/btrfs/ioctl.c | 7 +++++-- > 2 files changed, 6 insertions(+), 4 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index b2c3514..9bce6e9 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -4720,8 +4720,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, > if (S_ISREG(mode)) { > if (btrfs_test_opt(root, NODATASUM)) > BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; > - if (btrfs_test_opt(root, NODATACOW) || > - (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW)) > + if (btrfs_test_opt(root, NODATACOW)) > BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW; > } > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 00ddf22..2fd5455 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -140,8 +140,11 @@ void btrfs_inherit_iflags(struct inode *inode, struct inode *dir) > BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; > } > > - if (flags & BTRFS_INODE_NODATACOW) > - BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW; > + if (flags & BTRFS_INODE_NODATACOW) { > + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | > + if (S_ISREG(inode->i_mode)) > + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; > + } > This doesn't compile. Thanks, Josef