Re: [PATCH 12/16] SQUASHME pnfs-submit: reference layout across layoutcommit

[Boaz Harrosh <bharrosh@panasas.com>]

On 07/08/2010 01:34 AM, andros@netapp.com wrote:
> From: Andy Adamson <andros@netapp.com>
> 
> Signed-off-by: Andy Adamson <andros@netapp.com>
> ---
>  fs/nfs/nfs4proc.c |    2 ++
>  fs/nfs/pnfs.c     |   13 +++++++++++++
>  fs/nfs/pnfs.h     |    1 +
>  3 files changed, 16 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 6acebc3..f763746 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -5565,6 +5565,8 @@ static void pnfs_layoutcommit_release(void *lcdata)
>  	struct pnfs_layoutcommit_data *data =
>  		(struct pnfs_layoutcommit_data *)lcdata;
>  
> +	/* Matched by get_layout in pnfs_layoutcommit_inode */
> +	put_layout(data->args.inode);
>  	put_rpccred(data->cred);
>  	pnfs_layoutcommit_free(lcdata);
>  }
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index aa16e5d..d42c5da 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -354,6 +354,15 @@ put_layout_locked(struct pnfs_layout_type *lo)
>  }
>  
>  void
> +put_layout(struct inode *inode)
> +{
> +	spin_lock(&inode->i_lock);
> +	put_layout_locked(NFS_I(inode)->layout);
> +	spin_unlock(&inode->i_lock);
> +
> +}
> +
> +void
>  pnfs_layout_release(struct pnfs_layout_type *lo,
>  		    struct nfs4_pnfs_layout_segment *range)
>  {
> @@ -1598,6 +1607,9 @@ pnfs_layoutcommit_inode(struct inode *inode, int sync)
>  	__clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->layout->pnfs_layout_state);
>  	pnfs_get_layout_stateid(&data->args.stateid, nfsi->layout);
>  
> +	/* Reference for layoutcommit matched in pnfs_layoutcommit_release */
> +	get_layout(NFS_I(inode)->layout);
> +

Has of your rules this should be now called get_layout_locked

>  	spin_unlock(&inode->i_lock);
>  
>  	/* Set up layout commit args */
> @@ -1606,6 +1618,7 @@ pnfs_layoutcommit_inode(struct inode *inode, int sync)
>  	if (status) {
>  		/* The layout driver failed to setup the layoutcommit */
>  		put_rpccred(data->cred);
> +		put_layout(inode);

And it is really nice that put_layout takes an inode and get_layout takes an
struct layout_type.

>  		goto out_free;
>  	}
>  	status = pnfs4_proc_layoutcommit(data, sync);
> diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
> index 9b0fed4..e04b9d4 100644
> --- a/fs/nfs/pnfs.h
> +++ b/fs/nfs/pnfs.h
> @@ -64,6 +64,7 @@ void pnfs_layout_release(struct pnfs_layout_type *, struct nfs4_pnfs_layout_segm
>  void pnfs_set_layout_stateid(struct pnfs_layout_type *lo,
>  			     const nfs4_stateid *stateid);
>  void pnfs_destroy_layout(struct nfs_inode *);
> +void put_layout(struct inode *inode);
>  
>  #define PNFS_EXISTS_LDIO_OP(srv, opname) ((srv)->pnfs_curr_ld &&	\
>  				     (srv)->pnfs_curr_ld->ld_io_ops &&	\

I still think they can all go away.
What is the point of a layout without it's nfsi+inode. And who cares if we free the layout_type structure
2 milliseconds before, and in the error case?

Boaz