[PATCH] ceph: Don't do set_layout for file which has been written.

[PATCH] ceph: Don't do set_layout for file which has been written.

[majianpeng]

Cephfs don't change the layout which has been written.So add this check
before do.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
---
 fs/ceph/ioctl.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index e0b4ef3..cbea896 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -72,6 +72,9 @@ static long ceph_ioctl_set_layout(struct file *file, void __user *arg)
 	struct ceph_ioctl_layout nl;
 	int err;
 
+	/*Only for file which has never been written*/
+	if (i_size_read(inode) > 0 || ci->i_truncate_seq > 1)
+		return -ENOTEMPTY;
 	if (copy_from_user(&l, arg, sizeof(l)))
 		return -EFAULT;
 
-- 
1.8.1.2

Re: [PATCH] ceph: Don't do set_layout for file which has been written.

[Sage Weil]

On Thu, 11 Jul 2013, majianpeng wrote:
> Cephfs don't change the layout which has been written.So add this check
> before do.

This could conceivaably change in the future, and I'm not sure there is 
harm is the MDS round trip to get the error code here...?

sage

> 
> Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
> ---
>  fs/ceph/ioctl.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
> index e0b4ef3..cbea896 100644
> --- a/fs/ceph/ioctl.c
> +++ b/fs/ceph/ioctl.c
> @@ -72,6 +72,9 @@ static long ceph_ioctl_set_layout(struct file *file, void __user *arg)
>  	struct ceph_ioctl_layout nl;
>  	int err;
>  
> +	/*Only for file which has never been written*/
> +	if (i_size_read(inode) > 0 || ci->i_truncate_seq > 1)
> +		return -ENOTEMPTY;
>  	if (copy_from_user(&l, arg, sizeof(l)))
>  		return -EFAULT;
>  
> -- 
> 1.8.1.2
> N????y????b?????v?????{.n??????z??ay????????j\a???f????????????????:+v????????\a??zZ+??????"?!?

Re: Re: [PATCH] ceph: Don't do set_layout for file which has been written.

[majianpeng]

>On Thu, 11 Jul 2013, majianpeng wrote:
>> Cephfs don't change the layout which has been written.So add this check
>> before do.
>
>This could conceivaably change in the future, and I'm not sure there is 
>harm is the MDS round trip to get the error code here...?
>
Sorry, i can't understand what's your said. Can you explain in detail?

Thanks
Jianpeng Ma
[snip]

Re: Re: [PATCH] ceph: Don't do set_layout for file which has been written.

[Sage Weil]

On Fri, 12 Jul 2013, majianpeng wrote:
> >On Thu, 11 Jul 2013, majianpeng wrote:
> >> Cephfs don't change the layout which has been written.So add this check
> >> before do.
> >
> >This could conceivaably change in the future, and I'm not sure there is 
> >harm is the MDS round trip to get the error code here...?
> >
> Sorry, i can't understand what's your said. Can you explain in detail?

Sorry.  I mean that someday the MDS might be able to adjust the layout of 
an existing file.  That is probably not something that will happen any 
time soon, though.  It is probably worth merging this (along with the 
GETLAYOUT half) for now.

sage

Re: Re: [PATCH] ceph: Don't do set_layout for file which has been written.

[majianpeng]

>On Fri, 12 Jul 2013, majianpeng wrote:
>> >On Thu, 11 Jul 2013, majianpeng wrote:
>> >> Cephfs don't change the layout which has been written.So add this check
>> >> before do.
>> >
>> >This could conceivaably change in the future, and I'm not sure there is 
>> >harm is the MDS round trip to get the error code here...?
>> >
>> Sorry, i can't understand what's your said. Can you explain in detail?
>
>Sorry.  I mean that someday the MDS might be able to adjust the layout of 
>an existing file.  That is probably not something that will happen any 
>time soon, though.  It is probably worth merging this (along with the 
>GETLAYOUT half) for now.
>
OK, I see. Thanks your time!

Jianpeng
>sage