Ocfs2 devel - Jun 2010 - [PATCH] ocfs2: Remove the deprecated inode_setattr.

Nick has changed the turncate sequence and now inode_setattr
is deprecated. ocfs2 has done the most work of i_size change
before calling inode_setattr, so we are safe to just call
simple_setsize to update the i_size in vfs inode and then
generic_setattr.

As for dlmfs, we don't allow inode size change, so it is safe
for us to just call generic_setattr.

Cc: Nick Piggin <npiggin at suse.de>
Signed-off-by: Tao Ma <tao.ma at oracle.com>
---
 fs/ocfs2/dlmfs/dlmfs.c |    2 +-
 fs/ocfs2/file.c        |   18 +++++++++---------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index b83d610..e959b88 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -215,7 +215,7 @@ static int dlmfs_file_setattr(struct dentry *dentry, struct
iattr *attr)
 	attr->ia_valid &= ~ATTR_SIZE;
 	error = inode_change_ok(inode, attr);
 	if (!error)
-		error = inode_setattr(inode, attr);
+		generic_setattr(inode, attr);
 
 	return error;
 }
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 6a13ea6..06fd85c 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1052,17 +1052,17 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr
*attr)
 	}
 
 	/*
-	 * This will intentionally not wind up calling simple_setsize(),
-	 * since all the work for a size change has been done above.
-	 * Otherwise, we could get into problems with truncate as
-	 * ip_alloc_sem is used there to protect against i_size
-	 * changes.
+	 * Since all the work for a size change has been done above,
+	 * we only need to call simple_setsize to update i_size.
 	 */
-	status = inode_setattr(inode, attr);
-	if (status < 0) {
-		mlog_errno(status);
-		goto bail_commit;
+	if (attr->ia_valid & ATTR_SIZE) {
+		status = simple_setsize(inode, attr->ia_size);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail_commit;
+		}
 	}
+	generic_setattr(inode, attr);
 
 	status = ocfs2_mark_inode_dirty(handle, inode, bh);
 	if (status < 0)
-- 
1.5.5

On Wed, Jun 09, 2010 at 04:48:20PM +0800, Tao Ma wrote:
> Nick has changed the turncate sequence and now inode_setattr
> is deprecated. ocfs2 has done the most work of i_size change
> before calling inode_setattr, so we are safe to just call
> simple_setsize to update the i_size in vfs inode and then
> generic_setattr.
> 
> As for dlmfs, we don't allow inode size change, so it is safe
> for us to just call generic_setattr.
> 
> Cc: Nick Piggin <npiggin at suse.de>
> Signed-off-by: Tao Ma <tao.ma at oracle.com>
> ---
>  fs/ocfs2/dlmfs/dlmfs.c |    2 +-
>  fs/ocfs2/file.c        |   18 +++++++++---------
>  2 files changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
> index b83d610..e959b88 100644
> --- a/fs/ocfs2/dlmfs/dlmfs.c
> +++ b/fs/ocfs2/dlmfs/dlmfs.c
> @@ -215,7 +215,7 @@ static int dlmfs_file_setattr(struct dentry *dentry,
struct iattr *attr)
>  	attr->ia_valid &= ~ATTR_SIZE;
>  	error = inode_change_ok(inode, attr);
>  	if (!error)
> -		error = inode_setattr(inode, attr);
> +		generic_setattr(inode, attr);
This brings up my question again about simply _ignoring_ ATTR_SIZE changes.
One problem is that truncate calls which send down ATTR_SIZE might also
be sending down ATTR_MODE or ATTR_?TIME which should not be applied if
the ATTR_SIZE fails, one would think.

The other thing is that shouldn't we return -EINVAL or somesuch rather
than silently ignoring?

Anyway, several other pseudo filesystems do other stuff like tihs so
it's not something to bother with in this patch.

>  
>  	return error;
>  }
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 6a13ea6..06fd85c 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1052,17 +1052,17 @@ int ocfs2_setattr(struct dentry *dentry, struct
iattr *attr)
>  	}
>  
>  	/*
> -	 * This will intentionally not wind up calling simple_setsize(),
> -	 * since all the work for a size change has been done above.
> -	 * Otherwise, we could get into problems with truncate as
> -	 * ip_alloc_sem is used there to protect against i_size
> -	 * changes.
> +	 * Since all the work for a size change has been done above,
> +	 * we only need to call simple_setsize to update i_size.
>  	 */
> -	status = inode_setattr(inode, attr);
> -	if (status < 0) {
> -		mlog_errno(status);
> -		goto bail_commit;
> +	if (attr->ia_valid & ATTR_SIZE) {
> +		status = simple_setsize(inode, attr->ia_size);
> +		if (status < 0) {
> +			mlog_errno(status);
> +			goto bail_commit;
> +		}
>  	}
> +	generic_setattr(inode, attr);
>  
>  	status = ocfs2_mark_inode_dirty(handle, inode, bh);
>  	if (status < 0)
simple_setsize of course calls inode_newsize_ok, which may fail. If
you're committing your on-disk truncates at this point, you will
prefer to hoist that check as early as possible so you cannot fail
here.

Just open code the truncate part of simple_setsize for now.

Hi Nick,
	Thanks for the quick response.
On 06/09/2010 05:16 PM, Nick Piggin wrote:
> On Wed, Jun 09, 2010 at 04:48:20PM +0800, Tao Ma wrote:
>> Nick has changed the turncate sequence and now inode_setattr
>> is deprecated. ocfs2 has done the most work of i_size change
>> before calling inode_setattr, so we are safe to just call
>> simple_setsize to update the i_size in vfs inode and then
>> generic_setattr.
>>
>> As for dlmfs, we don't allow inode size change, so it is safe
>> for us to just call generic_setattr.
>>
>> Cc: Nick Piggin<npiggin at suse.de>
>> Signed-off-by: Tao Ma<tao.ma at oracle.com>
>> ---
>>   fs/ocfs2/dlmfs/dlmfs.c |    2 +-
>>   fs/ocfs2/file.c        |   18 +++++++++---------
>>   2 files changed, 10 insertions(+), 10 deletions(-)
>>
>> diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
>> index b83d610..e959b88 100644
>> --- a/fs/ocfs2/dlmfs/dlmfs.c
>> +++ b/fs/ocfs2/dlmfs/dlmfs.c
>> @@ -215,7 +215,7 @@ static int dlmfs_file_setattr(struct dentry
*dentry, struct iattr *attr)
>>   	attr->ia_valid&= ~ATTR_SIZE;
>>   	error = inode_change_ok(inode, attr);
>>   	if (!error)
>> -		error = inode_setattr(inode, attr);
>> +		generic_setattr(inode, attr);
>
> This brings up my question again about simply _ignoring_ ATTR_SIZE changes.
> One problem is that truncate calls which send down ATTR_SIZE might also
> be sending down ATTR_MODE or ATTR_?TIME which should not be applied if
> the ATTR_SIZE fails, one would think.
>
> The other thing is that shouldn't we return -EINVAL or somesuch rather
> than silently ignoring?
>
> Anyway, several other pseudo filesystems do other stuff like tihs so
> it's not something to bother with in this patch.
yeah, it looks that we have a little chance to fail out
here.
>
>
>>
>>   	return error;
>>   }
>> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
>> index 6a13ea6..06fd85c 100644
>> --- a/fs/ocfs2/file.c
>> +++ b/fs/ocfs2/file.c
>> @@ -1052,17 +1052,17 @@ int ocfs2_setattr(struct dentry *dentry, struct
iattr *attr)
>>   	}
>>
>>   	/*
>> -	 * This will intentionally not wind up calling simple_setsize(),
>> -	 * since all the work for a size change has been done above.
>> -	 * Otherwise, we could get into problems with truncate as
>> -	 * ip_alloc_sem is used there to protect against i_size
>> -	 * changes.
>> +	 * Since all the work for a size change has been done above,
>> +	 * we only need to call simple_setsize to update i_size.
>>   	 */
>> -	status = inode_setattr(inode, attr);
>> -	if (status<  0) {
>> -		mlog_errno(status);
>> -		goto bail_commit;
>> +	if (attr->ia_valid&  ATTR_SIZE) {
>> +		status = simple_setsize(inode, attr->ia_size);
>> +		if (status<  0) {
>> +			mlog_errno(status);
>> +			goto bail_commit;
>> +		}
>>   	}
>> +	generic_setattr(inode, attr);
>>
>>   	status = ocfs2_mark_inode_dirty(handle, inode, bh);
>>   	if (status<  0)
>
> simple_setsize of course calls inode_newsize_ok, which may fail. If
> you're committing your on-disk truncates at this point, you will
> prefer to hoist that check as early as possible so you cannot fail
> here.
>
We have a inode_newsize_ok check at the top of ocfs2_setattr when we do 
the real work of truncate(it is far above, so the patch can't have it. 
;) ). So we don't need to worry about that actually.
> Just open code the truncate part of simple_setsize for now.
Regards,
Tao

Tao, can you rebase this in Al's vfs.git for-next queue (or just
linux-next which includes it)

There's lots of changes to the calling sequences in that area in there
and having all conversions based ontop of that would make life a lot
simpler for everyone.

On Wed, Jun 09, 2010 at 04:48:20PM +0800, Tao Ma wrote:
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 6a13ea6..06fd85c 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1052,17 +1052,17 @@ int ocfs2_setattr(struct dentry *dentry, struct
iattr *attr)
>  	}
>  
>  	/*
> -	 * This will intentionally not wind up calling simple_setsize(),
> -	 * since all the work for a size change has been done above.
> -	 * Otherwise, we could get into problems with truncate as
> -	 * ip_alloc_sem is used there to protect against i_size
> -	 * changes.
> +	 * Since all the work for a size change has been done above,
> +	 * we only need to call simple_setsize to update i_size.
>  	 */
> -	status = inode_setattr(inode, attr);
> -	if (status < 0) {
> -		mlog_errno(status);
> -		goto bail_commit;
> +	if (attr->ia_valid & ATTR_SIZE) {
> +		status = simple_setsize(inode, attr->ia_size);
> +		if (status < 0) {
> +			mlog_errno(status);
> +			goto bail_commit;
> +		}
	Boy, this is a bit to think about.  The old code deliberately
used vmtruncate() to update i_size and trim the pagecace, but because we
didn't implement ->truncate() we knew that we wouldn't modify the
(already adjusted) allocation.  Not buggy, Christoph, just a roundabout
way to get the job done.
	The new simple_setsize() does nothing but update i_size and trim
the pagecache, right Nick?  If that's so, that's all we need.

Joel

-- 

"Also, all of life's big problems include the words
'indictment' or
	'inoperable.' Everything else is small stuff."
	- Alton Brown

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127