[PATCH 1/2] btrfs: Check if dest_offset is block-size aligned before cloning file

[PATCH 1/2] btrfs: Check if dest_offset is block-size aligned before cloning file

[Li Zefan]

We've done the check for src_offset and src_length, and We should
also check dest_offset, otherwise we'll corrupt the destination
file:

  (After cloning file1 to file2 with unaligned dest_offset)
  # cat /mnt/file2
  cat: /mnt/file2: Input/output error

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 fs/btrfs/ioctl.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 463d91b..81b47bd 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1669,12 +1669,11 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 		olen = len = src->i_size - off;
 	/* if we extend to eof, continue to block boundary */
 	if (off + len == src->i_size)
-		len = ((src->i_size + bs-1) & ~(bs-1))
-			- off;
+		len = ALIGN(src->i_size, bs) - off;
 
 	/* verify the end result is block aligned */
-	if ((off & (bs-1)) ||
-	    ((off + len) & (bs-1)))
+	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
+	    !IS_ALIGNED(destoff, bs))
 		goto out_unlock;
 
 	/* do any pending delalloc/csum calc on src, one way or
-- 
1.6.3

[PATCH 2/2] btrfs: Set file size correctly in file clone

[Li Zefan]

Set src_offset = 0, src_length = 20K, dest_offset = 20K. And the
original filesize of the dest file 'file2' is 30K:

  # ls -l /mnt/file2
  -rw-r--r-- 1 root root 30720 Nov 18 16:42 /mnt/file2

Now clone file1 to file2, the dest file should be 40K, but it
still shows 30K:

  # ls -l /mnt/file2
  -rw-r--r-- 1 root root 30720 Nov 18 16:42 /mnt/file2

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 fs/btrfs/ioctl.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 81b47bd..6b4bfa7 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1873,8 +1873,8 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 			 * but shouldn't round up the file size
 			 */
 			endoff = new_key.offset + datal;
-			if (endoff > off+olen)
-				endoff = off+olen;
+			if (endoff > destoff+olen)
+				endoff = destoff+olen;
 			if (endoff > inode->i_size)
 				btrfs_i_size_write(inode, endoff);
 
-- 
1.6.3

Re: [PATCH 1/2] btrfs: Check if dest_offset is block-size aligned before cloning file

[Sage Weil]

On Fri, 19 Nov 2010, Li Zefan wrote:
> We've done the check for src_offset and src_length, and We should
> also check dest_offset, otherwise we'll corrupt the destination
> file:
> 
>   (After cloning file1 to file2 with unaligned dest_offset)
>   # cat /mnt/file2
>   cat: /mnt/file2: Input/output error
> 
> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> ---
>  fs/btrfs/ioctl.c |    7 +++----
>  1 files changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 463d91b..81b47bd 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -1669,12 +1669,11 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
>  		olen = len = src->i_size - off;
>  	/* if we extend to eof, continue to block boundary */
>  	if (off + len == src->i_size)
> -		len = ((src->i_size + bs-1) & ~(bs-1))
> -			- off;
> +		len = ALIGN(src->i_size, bs) - off;
>  
>  	/* verify the end result is block aligned */
> -	if ((off & (bs-1)) ||
> -	    ((off + len) & (bs-1)))
> +	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
> +	    !IS_ALIGNED(destoff, bs))
>  		goto out_unlock;
>  
>  	/* do any pending delalloc/csum calc on src, one way or

Looks good.

Reviewed-by: Sage Weil <sage@newdream.net>

Re: [PATCH 2/2] btrfs: Set file size correctly in file clone

[Sage Weil]

On Fri, 19 Nov 2010, Li Zefan wrote:
> Set src_offset = 0, src_length = 20K, dest_offset = 20K. And the
> original filesize of the dest file 'file2' is 30K:
> 
>   # ls -l /mnt/file2
>   -rw-r--r-- 1 root root 30720 Nov 18 16:42 /mnt/file2
> 
> Now clone file1 to file2, the dest file should be 40K, but it
> still shows 30K:
> 
>   # ls -l /mnt/file2
>   -rw-r--r-- 1 root root 30720 Nov 18 16:42 /mnt/file2
> 
> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> ---
>  fs/btrfs/ioctl.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 81b47bd..6b4bfa7 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -1873,8 +1873,8 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
>  			 * but shouldn't round up the file size
>  			 */
>  			endoff = new_key.offset + datal;
> -			if (endoff > off+olen)
> -				endoff = off+olen;
> +			if (endoff > destoff+olen)
> +				endoff = destoff+olen;
>  			if (endoff > inode->i_size)
>  				btrfs_i_size_write(inode, endoff);

Reviewed-by: Sage Weil <sage@newdream.net>