[PATCH v3 2/2] NFSD: Implement SEEK

Anna.Schumaker
2014-09-26T17:58:33Z

From: Anna Schumaker <Anna.Schumaker@netapp.com>

This patch adds server support for the NFS v4.2 operation SEEK, which
returns the position of the next hole or data segment in a file.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---
fs/nfsd/nfs4proc.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/nfsd/nfs4xdr.c | 36 ++++++++++++++++++++++++++++++++++--
fs/nfsd/xdr4.h | 14 ++++++++++++++
include/linux/nfs4.h | 5 +++++
4 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 5e0dc52..cdeb3cf 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1013,6 +1013,49 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
return status;
}

+static __be32
+nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+ struct nfsd4_seek *seek)
+{
+ int whence;
+ __be32 status;
+ struct file *file;
+
+ status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
+ &seek->seek_stateid,
+ RD_STATE, &file);
+ if (status) {
+ dprintk("NFSD: nfsd4_seek: couldn't process stateid!\n");
+ return status;
+ }
+
+ switch (seek->seek_whence) {
+ case NFS4_CONTENT_DATA:
+ whence = SEEK_DATA;
+ break;
+ case NFS4_CONTENT_HOLE:
+ whence = SEEK_HOLE;
+ break;
+ default:
+ status = nfserr_union_notsupp;
+ goto out;
+ }
+
+ /*
+ * Note: This call does change file->f_pos, but nothing in NFSD
+ * should ever file->f_pos.
+ */
+ seek->seek_pos = vfs_llseek(file, seek->seek_offset, whence);
+ if (seek->seek_pos < 0)
+ status = nfserrno(seek->seek_pos);
+ else if (seek->seek_pos >= i_size_read(file_inode(file)))
+ seek->seek_eof = true;
+
+out:
+ fput(file);
+ return status;
+}
+
/* This routine never returns NFS_OK! If there are no other errors, it
* will return NFSERR_SAME or NFSERR_NOT_SAME depending on whether the
* attributes matched. VERIFY is implemented by mapping NFSERR_SAME
@@ -1881,6 +1924,12 @@ static struct nfsd4_operation nfsd4_ops[] = {
.op_get_currentstateid = (stateid_getter)nfsd4_get_freestateid,
.op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
},
+
+ /* NFSv4.2 operations */
+ [OP_SEEK] = {
+ .op_func = (nfsd4op_func)nfsd4_seek,
+ .op_name = "OP_SEEK",
+ },
};

int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 94dde7b..d20e0a5 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1521,6 +1521,22 @@ static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, str
}

static __be32
+nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
+{
+ DECODE_HEAD;
+
+ status = nfsd4_decode_stateid(argp, &seek->seek_stateid);
+ if (status)
+ return status;
+
+ READ_BUF(8 + 4);
+ p = xdr_decode_hyper(p, &seek->seek_offset);
+ seek->seek_whence = be32_to_cpup(p);
+
+ DECODE_TAIL;
+}
+
+static __be32
nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
{
return nfs_ok;
@@ -1605,7 +1621,7 @@ static nfsd4_dec nfsd4_dec_ops[] = {
[OP_OFFLOAD_CANCEL] = (nfsd4_dec)nfsd4_decode_notsupp,
[OP_OFFLOAD_STATUS] = (nfsd4_dec)nfsd4_decode_notsupp,
[OP_READ_PLUS] = (nfsd4_dec)nfsd4_decode_notsupp,
- [OP_SEEK] = (nfsd4_dec)nfsd4_decode_notsupp,
+ [OP_SEEK] = (nfsd4_dec)nfsd4_decode_seek,
[OP_WRITE_SAME] = (nfsd4_dec)nfsd4_decode_notsupp,
};

@@ -3765,6 +3781,22 @@ nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
}

static __be32
+nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
+ struct nfsd4_seek *seek)
+{
+ __be32 *p;
+
+ if (nfserr)
+ return nfserr;
+
+ p = xdr_reserve_space(&resp->xdr, 4 + 8);
+ *p++ = cpu_to_be32(seek->seek_eof);
+ p = xdr_encode_hyper(p, seek->seek_pos);
+
+ return nfserr;
+}
+
+static __be32
nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
{
return nfserr;
@@ -3848,7 +3880,7 @@ static nfsd4_enc nfsd4_enc_ops[] = {
[OP_OFFLOAD_CANCEL] = (nfsd4_enc)nfsd4_encode_noop,
[OP_OFFLOAD_STATUS] = (nfsd4_enc)nfsd4_encode_noop,
[OP_READ_PLUS] = (nfsd4_enc)nfsd4_encode_noop,
- [OP_SEEK] = (nfsd4_enc)nfsd4_encode_noop,
+ [OP_SEEK] = (nfsd4_enc)nfsd4_encode_seek,
[OP_WRITE_SAME] = (nfsd4_enc)nfsd4_encode_noop,
};

diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 465e779..5720e94 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -428,6 +428,17 @@ struct nfsd4_reclaim_complete {
u32 rca_one_fs;
};

+struct nfsd4_seek {
+ /* request */
+ stateid_t seek_stateid;
+ loff_t seek_offset;
+ u32 seek_whence;
+
+ /* response */
+ u32 seek_eof;
+ loff_t seek_pos;
+};
+
struct nfsd4_op {
int opnum;
__be32 status;
@@ -473,6 +484,9 @@ struct nfsd4_op {
struct nfsd4_reclaim_complete reclaim_complete;
struct nfsd4_test_stateid test_stateid;
struct nfsd4_free_stateid free_stateid;
+
+ /* NFSv4.2 */
+ struct nfsd4_seek seek;
} u;
struct nfs4_replay * replay;
};
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index cf38224..026b0c0 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -550,4 +550,9 @@ struct nfs4_deviceid {
char data[NFS4_DEVICEID4_SIZE];
};

+enum data_content4 {
+ NFS4_CONTENT_DATA = 0,
+ NFS4_CONTENT_HOLE = 1,
+};
+
#endif
--
2.1.0