diff mbox

[v2,1/6] Btrfs: fix a bug of per-file nocow

Message ID 1347069690-30223-2-git-send-email-bo.li.liu@oracle.com (mailing list archive)
State New, archived
Headers show

Commit Message

Liu Bo Sept. 8, 2012, 2:01 a.m. UTC
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 <bo.li.liu@oracle.com>
---
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(-)

Comments

Josef Bacik Sept. 10, 2012, 7:18 p.m. UTC | #1
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 <bo.li.liu@oracle.com>
> ---
> 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
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diff mbox

Patch

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;
+	}
 
 	btrfs_update_iflags(inode);
 }