Re: [PATCH 2/3] nfsd: Add ALLOCATE support

["J. Bruce Fields" <bfields@fieldses.org>]

On Tue, Sep 09, 2014 at 10:49:41AM -0400, Anna.Schumaker@netapp.com wrote:
> From: Anna Schumaker <Anna.Schumaker@Netapp.com>
> 
> The ALLOCATE operation is used to preallocate space in a file.  I use
> vfs_fallocate() to do the actual preallocation.
> 
> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
> ---
>  fs/nfsd/nfs4proc.c | 29 +++++++++++++++++++++++++++++
>  fs/nfsd/nfs4xdr.c  | 19 ++++++++++++++++++-
>  fs/nfsd/vfs.c      |  9 +++++++++
>  fs/nfsd/vfs.h      |  1 +
>  fs/nfsd/xdr4.h     |  8 ++++++++
>  5 files changed, 65 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 9fd2b78..f9d8fac 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -1014,6 +1014,28 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  }
>  
>  static __be32
> +nfsd4_allocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> +		struct nfsd4_allocate *allocate)
> +{
> +	__be32 status = nfserr_notsupp;
> +	struct file *file;
> +
> +	status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
> +					    &allocate->alloc_stateid,
> +					    WR_STATE, &file);

This checks that the stateid's openmode is write but not that the caller
has permission to write.  I think you want an nfsd_permission() check in
nfsd4_vfs_allocate.

(Incidentally, the spec doesn't say anything about checking either, I
wonder if it should?)

> +	if (status != nfs_ok) {
> +		dprintk("NFSD: nfsd4_allocate: couldn't process stateid!\n");
> +		return status;
> +	}
> +
> +	status = nfsd4_vfs_fallocate(&cstate->current_fh, file,
> +				     allocate->alloc_offset,
> +				     allocate->alloc_length);
> +	fput(file);
> +	return status;
> +}
> +
> +static __be32
>  nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  		struct nfsd4_seek *seek)
>  {
> @@ -1920,6 +1942,13 @@ static struct nfsd4_operation nfsd4_ops[] = {
>  	},
>  
>  	/* NFSv4.2 operations */
> +	[OP_ALLOCATE] = {
> +		.op_func = (nfsd4op_func)nfsd4_allocate,
> +		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
> +		.op_name = "OP_ALLOCATE",
> +		.op_rsize_bop = (nfsd4op_rsize)nfsd4_write_rsize,
> +		.op_get_currentstateid = (stateid_getter)nfsd4_get_writestateid,
> +	},
>  	[OP_SEEK] = {
>  		.op_func = (nfsd4op_func)nfsd4_seek,
>  		.op_name = "OP_SEEK",
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 57b3973..a55aa3b 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -1521,6 +1521,23 @@ static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, str
>  }
>  
>  static __be32
> +nfsd4_decode_allocate(struct nfsd4_compoundargs *argp,
> +		      struct nfsd4_allocate *allocate)
> +{
> +	DECODE_HEAD;
> +
> +	status = nfsd4_decode_stateid(argp, &allocate->alloc_stateid);
> +	if (status)
> +		return status;
> +
> +	READ_BUF(16);
> +	p = xdr_decode_hyper(p, &allocate->alloc_offset);
> +	xdr_decode_hyper(p, &allocate->alloc_length);
> +
> +	DECODE_TAIL;
> +}
> +
> +static __be32
>  nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
>  {
>  	DECODE_HEAD;
> @@ -1611,7 +1628,7 @@ static nfsd4_dec nfsd4_dec_ops[] = {
>  	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
>  
>  	/* new operations for NFSv4.2 */
> -	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_notsupp,
> +	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_allocate,
>  	[OP_COPY]		= (nfsd4_dec)nfsd4_decode_notsupp,
>  	[OP_COPY_NOTIFY]	= (nfsd4_dec)nfsd4_decode_notsupp,
>  	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_notsupp,
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index f501a9b..4b1dba0 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -16,6 +16,7 @@
>  #include <linux/fs.h>
>  #include <linux/file.h>
>  #include <linux/splice.h>
> +#include <linux/falloc.h>
>  #include <linux/fcntl.h>
>  #include <linux/namei.h>
>  #include <linux/delay.h>
> @@ -523,6 +524,14 @@ __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
>  }
>  #endif
>  
> +__be32 nfsd4_vfs_fallocate(struct svc_fh *fhp, struct file *file,
> +			   loff_t offset, loff_t len)
> +{
> +	int error = vfs_fallocate(file, 0, offset, len);
> +	if (error < 0)
> +		return nfserrno(error);
> +	return nfserrno(commit_metadata(fhp));
> +}
>  #endif /* defined(CONFIG_NFSD_V4) */
>  
>  #ifdef CONFIG_NFSD_V3
> diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
> index c2ff3f1..9d88c88 100644
> --- a/fs/nfsd/vfs.h
> +++ b/fs/nfsd/vfs.h
> @@ -54,6 +54,7 @@ int nfsd_mountpoint(struct dentry *, struct svc_export *);
>  #ifdef CONFIG_NFSD_V4
>  __be32          nfsd4_set_nfs4_label(struct svc_rqst *, struct svc_fh *,
>  		    struct xdr_netobj *);
> +__be32		nfsd4_vfs_fallocate(struct svc_fh *, struct file *, loff_t, loff_t);
>  #endif /* CONFIG_NFSD_V4 */
>  __be32		nfsd_create(struct svc_rqst *, struct svc_fh *,
>  				char *name, int len, struct iattr *attrs,
> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> index 5720e94..4a01fa8 100644
> --- a/fs/nfsd/xdr4.h
> +++ b/fs/nfsd/xdr4.h
> @@ -428,6 +428,13 @@ struct nfsd4_reclaim_complete {
>  	u32 rca_one_fs;
>  };
>  
> +struct nfsd4_allocate {
> +	/* request */
> +	stateid_t	alloc_stateid;
> +	loff_t		alloc_offset;
> +	u64		alloc_length;
> +};
> +
>  struct nfsd4_seek {
>  	/* request */
>  	stateid_t	seek_stateid;
> @@ -486,6 +493,7 @@ struct nfsd4_op {
>  		struct nfsd4_free_stateid	free_stateid;
>  
>  		/* NFSv4.2 */
> +		struct nfsd4_allocate		allocate;
>  		struct nfsd4_seek		seek;
>  	} u;
>  	struct nfs4_replay *			replay;
> -- 
> 2.1.0
>