NFSD: Implement SEEK

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>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 5e0dc528a0e8c7e654867adfefe48ed4a0c3c678..cdeb3cfd6f32b2d412c8478283c8ffc732d6dc06 100644 (file)
--- 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 0311baebd7d39f834f7b8fb892e215f1c6f71c97..7ec646380005a1383cf1b1f1e97dfd3e21f6605b 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1513,6 +1513,22 @@ static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, str
        DECODE_TAIL;
 }
 
+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)
 {
@@ -1598,7 +1614,7 @@ 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,
        return 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)
 {
@@ -3849,7 +3881,7 @@ 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 465e7799742a399fe07878af06db0b3f35bc35df..5720e9457f3324a29dbdd68551a8a129a6e3db6e 100644 (file)
--- 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 cf38224c4fa0e326e1e7c51679bba5a0eed07aa3..026b0c042c4090fb7b903d10d9ad8a165d19695a 100644 (file)
--- 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