NFS: Implement SEEK

The SEEK operation is used when an application makes an lseek call with
either the SEEK_HOLE or SEEK_DATA flags set.  I fall back on
nfs_file_llseek() if the server does not have SEEK support.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

3 files changed, 23 insertions, 0 deletions

diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 026b0c042c40..356acc2846fd 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -487,6 +487,9 @@ enum {
         NFSPROC4_CLNT_GETDEVICELIST,
         NFSPROC4_CLNT_BIND_CONN_TO_SESSION,
         NFSPROC4_CLNT_DESTROY_CLIENTID,
+
+        /* nfs42 */
+        NFSPROC4_CLNT_SEEK,
 };
 
 /* nfs41 types */
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 922be2e050f5..a32ba0d7a98f 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -230,5 +230,6 @@ struct nfs_server {
 #define NFS_CAP_STATEID_NFSV41  (1U << 16)
 #define NFS_CAP_ATOMIC_OPEN_V1  (1U << 17)
 #define NFS_CAP_SECURITY_LABEL  (1U << 18)
+#define NFS_CAP_SEEK            (1U << 19)
 
 #endif
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 0040629894df..0051b1ad2b37 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1239,6 +1239,25 @@ struct pnfs_ds_commit_info {
 
 #endif /* CONFIG_NFS_V4_1 */
 
+#ifdef CONFIG_NFS_V4_2
+struct nfs42_seek_args {
+        struct nfs4_sequence_args       seq_args;
+
+        struct nfs_fh                   *sa_fh;
+        nfs4_stateid                    sa_stateid;
+        u64                             sa_offset;
+        u32                             sa_what;
+};
+
+struct nfs42_seek_res {
+        struct nfs4_sequence_res        seq_res;
+        unsigned int                    status;
+
+        u32     sr_eof;
+        u64     sr_offset;
+};
+#endif
+
 struct nfs_page;
 
 #define NFS_PAGEVEC_SIZE        (8U)