[v1,4/8] btrfs: Add mountpoint checking during btrfs_copy_file_range
diff mbox

Message ID 1441397823-1203-5-git-send-email-Anna.Schumaker@Netapp.com
State New
Headers show

Commit Message

Schumaker, Anna Sept. 4, 2015, 8:16 p.m. UTC
We need to verify that both the source and the destination files are
part of the same filesystem, otherwise we can't create a reflink.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---
 fs/btrfs/ioctl.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

David Sterba Sept. 9, 2015, 9:18 a.m. UTC | #1
On Fri, Sep 04, 2015 at 04:16:58PM -0400, Anna Schumaker wrote:
> We need to verify that both the source and the destination files are
> part of the same filesystem, otherwise we can't create a reflink.
> 
> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
> ---
>  fs/btrfs/ioctl.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 62ae286..9c0c955 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3856,6 +3856,10 @@ ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
>  {
>  	ssize_t ret;
>  
> +	if (inode_in->i_sb != inode_out->i_sb ||
> +	    file_in->f_path.mnt != file_out->f_path.mnt)
> +		return -EXDEV;

The same check exists in btrfs_clone_files (added in the previous
patch), what's the reason to add it here again?

> +
>  	ret = btrfs_clone_files(file_out, file_in, pos_in, len, pos_out);
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Schumaker, Anna Sept. 9, 2015, 3:56 p.m. UTC | #2
On 09/09/2015 05:18 AM, David Sterba wrote:
> On Fri, Sep 04, 2015 at 04:16:58PM -0400, Anna Schumaker wrote:
>> We need to verify that both the source and the destination files are
>> part of the same filesystem, otherwise we can't create a reflink.
>>
>> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
>> ---
>>  fs/btrfs/ioctl.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
>> index 62ae286..9c0c955 100644
>> --- a/fs/btrfs/ioctl.c
>> +++ b/fs/btrfs/ioctl.c
>> @@ -3856,6 +3856,10 @@ ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
>>  {
>>  	ssize_t ret;
>>  
>> +	if (inode_in->i_sb != inode_out->i_sb ||
>> +	    file_in->f_path.mnt != file_out->f_path.mnt)
>> +		return -EXDEV;
> 
> The same check exists in btrfs_clone_files (added in the previous
> patch), what's the reason to add it here again?

To be really, really sure that it's not a cross-device copy?  :)

In reality, it was an oversight and I'll drop the patch.  Thanks for letting me know!

Anna

> 
>> +
>>  	ret = btrfs_clone_files(file_out, file_in, pos_in, len, pos_out);

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Patch
diff mbox

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 62ae286..9c0c955 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3856,6 +3856,10 @@  ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
 {
 	ssize_t ret;
 
+	if (inode_in->i_sb != inode_out->i_sb ||
+	    file_in->f_path.mnt != file_out->f_path.mnt)
+		return -EXDEV;
+
 	ret = btrfs_clone_files(file_out, file_in, pos_in, len, pos_out);
 	if (ret == 0)
 		ret = len;