[pnfs] [PATCH 16/37] pnfs: allocate layout driver data in one piece with pnfs_layout_type

[Dean Hildebrand]

>layout driver data comes right after the pnfs_layout_type fields
>and can be accessed with the PNFS_LD_DATA accessor function.


>  
>  /* Free a filelayout layout structure
> @@ -429,17 +418,11 @@ void
>  filelayout_free_layout(struct pnfs_layout_type **layoutidp,
>  		       struct nfs4_pnfs_layout_segment *range)
>  {
> -	struct nfs4_filelayout *nfslay = NULL;
>  	struct pnfs_layout_type *layoutid;
>  
>  	dprintk("NFS_FILELAYOUT: freeing layout\n");
>  
>  	layoutid = *layoutidp;
> -	if (layoutid)
> -		nfslay = (struct nfs4_filelayout *)layoutid->layoutid;
> -	if (nfslay != NULL)
> -		kfree(nfslay);
> -	kfree(layoutid);
>  	*layoutidp = NULL;
>  }
>  
>   
The above code seems to remove some parts of the function but leaves the 
"layoutid = *layoutidp" part for some reason?  Where does the memory get 
freed?

There seems to be a lot more happening in this patch than just a 
conversion to accessor functions as described at the top.  Does it need 
a more expansive comment or is extra code being included?


> @@ -459,9 +442,7 @@ filelayout_set_layout(struct pnfs_layout_type *layoutid,
>  
>  	if (!layoutid)
>  		goto nfserr;
> -	fl = (struct nfs4_filelayout *)layoutid->layoutid;
> -	if (!fl)
> -		goto nfserr;
> +	fl = PNFS_LD_DATA(layoutid);
>  
>  	READ32(fl->dev_id);
>  	READ32(nfl_util);
> @@ -503,7 +484,6 @@ filelayout_commit(struct pnfs_layout_type *layoutid, struct list_head *pages,
>  {
>  	struct inode *ino = PNFS_INODE(layoutid);
>  	struct nfs_write_data   *dsdata = NULL;
> -	struct pnfs_layout_type *laytype;
>  	struct nfs4_filelayout *nfslay;
>  	struct nfs4_pnfs_dev_item *dev;
>  	struct nfs4_pnfs_dev *fdev;
> @@ -514,8 +494,7 @@ filelayout_commit(struct pnfs_layout_type *layoutid, struct list_head *pages,
>  	struct list_head *pos, *tmp;
>  	int i;
>  
> -	laytype = NFS_I(ino)->current_layout;
> -	nfslay = (struct nfs4_filelayout *)layoutid->layoutid;
> +	nfslay = PNFS_LD_DATA(layoutid);
>  
>  	dprintk("%s data %p pnfs_client %p nfslay %p\n",
>  			__FUNCTION__, data, data->pnfs_client, nfslay);
> @@ -599,7 +578,7 @@ out_bad:
>  ssize_t
>  filelayout_get_stripesize(struct pnfs_layout_type *layoutid)
>  {
> -	struct nfs4_filelayout *fl = (struct nfs4_filelayout *)layoutid->layoutid;
> +	struct nfs4_filelayout *fl = PNFS_LD_DATA(layoutid);
>  	ssize_t stripesize = fl->stripe_unit;
>  	return stripesize;
>  }
> diff --git a/include/linux/nfs4_pnfs.h b/include/linux/nfs4_pnfs.h
> index 6a98f59..d862aac 100644
> --- a/include/linux/nfs4_pnfs.h
> +++ b/include/linux/nfs4_pnfs.h
> @@ -37,9 +37,9 @@ struct pnfs_mount_type {
>   * A reference is stored in the nfs_inode structure.
>   */
>  struct pnfs_layout_type {
> -	void *layoutid;
> -	int roc_iomode;	/* iomode to return on close, 0=none */
> +	int roc_iomode;			/* iomode to return on close, 0=none */
>  	struct inode *inode;
> +	u8 ld_data[];			/* layout driver private data */
>  };
>  
>  static inline struct inode *
> @@ -66,6 +66,12 @@ PNFS_MOUNTID(struct pnfs_layout_type *lo)
>  	return NFS_SERVER(PNFS_INODE(lo))->pnfs_mountid;
>  }
>  
> +static inline void *
> +PNFS_LD_DATA(struct pnfs_layout_type *lo)
> +{
> +	return lo->ld_data;
> +}
> +
>  static inline struct pnfs_layoutdriver_type *
>  PNFS_LD(struct pnfs_layout_type *lo)
>  {
>