5 files changed, 203 insertions, 0 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index efa6ae822ca8..af32d3df0544 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5834,6 +5834,54 @@ int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp)
         return status;
 }
 
+/*
+ * Retrieve the list of Data Server devices from the MDS.
+ */
+static int _nfs4_getdevicelist(struct nfs_server *server,
+                                    const struct nfs_fh *fh,
+                                    struct pnfs_devicelist *devlist)
+{
+        struct nfs4_getdevicelist_args args = {
+                .fh = fh,
+                .layoutclass = server->pnfs_curr_ld->id,
+        };
+        struct nfs4_getdevicelist_res res = {
+                .devlist = devlist,
+        };
+        struct rpc_message msg = {
+                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETDEVICELIST],
+                .rpc_argp = &args,
+                .rpc_resp = &res,
+        };
+        int status;
+
+        dprintk("--> %s\n", __func__);
+        status = nfs4_call_sync(server->client, server, &msg, &args.seq_args,
+                                &res.seq_res, 0);
+        dprintk("<-- %s status=%d\n", __func__, status);
+        return status;
+}
+
+int nfs4_proc_getdevicelist(struct nfs_server *server,
+                            const struct nfs_fh *fh,
+                            struct pnfs_devicelist *devlist)
+{
+        struct nfs4_exception exception = { };
+        int err;
+
+        do {
+                err = nfs4_handle_exception(server,
+                                _nfs4_getdevicelist(server, fh, devlist),
+                                &exception);
+        } while (exception.retry);
+
+        dprintk("%s: err=%d, num_devs=%u\n", __func__,
+                err, devlist->num_devs);
+
+        return err;
+}
+EXPORT_SYMBOL_GPL(nfs4_proc_getdevicelist);
+
 static int
 _nfs4_proc_getdeviceinfo(struct nfs_server *server, struct pnfs_device *pdev)
 {
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index b851b560a6f8..5f769f8d05b0 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -314,6 +314,17 @@ static int nfs4_stat_to_errno(int);
                                 XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5)
 #define encode_reclaim_complete_maxsz   (op_encode_hdr_maxsz + 4)
 #define decode_reclaim_complete_maxsz   (op_decode_hdr_maxsz + 4)
+#define encode_getdevicelist_maxsz (op_encode_hdr_maxsz + 4 + \
+                                encode_verifier_maxsz)
+#define decode_getdevicelist_maxsz (op_decode_hdr_maxsz + \
+                                2 /* nfs_cookie4 gdlr_cookie */ + \
+                                decode_verifier_maxsz \
+                                  /* verifier4 gdlr_verifier */ + \
+                                1 /* gdlr_deviceid_list count */ + \
+                                XDR_QUADLEN(NFS4_PNFS_GETDEVLIST_MAXNUM * \
+                                            NFS4_DEVICEID4_SIZE) \
+                                  /* gdlr_deviceid_list */ + \
+                                1 /* bool gdlr_eof */)
 #define encode_getdeviceinfo_maxsz (op_encode_hdr_maxsz + 4 + \
                                 XDR_QUADLEN(NFS4_DEVICEID4_SIZE))
 #define decode_getdeviceinfo_maxsz (op_decode_hdr_maxsz + \
@@ -748,6 +759,14 @@ static int nfs4_stat_to_errno(int);
 #define NFS4_dec_reclaim_complete_sz    (compound_decode_hdr_maxsz + \
                                          decode_sequence_maxsz + \
                                          decode_reclaim_complete_maxsz)
+#define NFS4_enc_getdevicelist_sz (compound_encode_hdr_maxsz + \
+                                encode_sequence_maxsz + \
+                                encode_putfh_maxsz + \
+                                encode_getdevicelist_maxsz)
+#define NFS4_dec_getdevicelist_sz (compound_decode_hdr_maxsz + \
+                                decode_sequence_maxsz + \
+                                decode_putfh_maxsz + \
+                                decode_getdevicelist_maxsz)
 #define NFS4_enc_getdeviceinfo_sz (compound_encode_hdr_maxsz +    \
                                 encode_sequence_maxsz +\
                                 encode_getdeviceinfo_maxsz)
@@ -1855,6 +1874,26 @@ static void encode_sequence(struct xdr_stream *xdr,
 
 #ifdef CONFIG_NFS_V4_1
 static void
+encode_getdevicelist(struct xdr_stream *xdr,
+                     const struct nfs4_getdevicelist_args *args,
+                     struct compound_hdr *hdr)
+{
+        __be32 *p;
+        nfs4_verifier dummy = {
+                .data = "dummmmmy",
+        };
+
+        p = reserve_space(xdr, 20);
+        *p++ = cpu_to_be32(OP_GETDEVICELIST);
+        *p++ = cpu_to_be32(args->layoutclass);
+        *p++ = cpu_to_be32(NFS4_PNFS_GETDEVLIST_MAXNUM);
+        xdr_encode_hyper(p, 0ULL);                          /* cookie */
+        encode_nfs4_verifier(xdr, &dummy);
+        hdr->nops++;
+        hdr->replen += decode_getdevicelist_maxsz;
+}
+
+static void
 encode_getdeviceinfo(struct xdr_stream *xdr,
                      const struct nfs4_getdeviceinfo_args *args,
                      struct compound_hdr *hdr)
@@ -2775,6 +2814,24 @@ static void nfs4_xdr_enc_reclaim_complete(struct rpc_rqst *req,
 }
 
 /*
+ * Encode GETDEVICELIST request
+ */
+static void nfs4_xdr_enc_getdevicelist(struct rpc_rqst *req,
+                                       struct xdr_stream *xdr,
+                                       struct nfs4_getdevicelist_args *args)
+{
+        struct compound_hdr hdr = {
+                .minorversion = nfs4_xdr_minorversion(&args->seq_args),
+        };
+
+        encode_compound_hdr(xdr, req, &hdr);
+        encode_sequence(xdr, &args->seq_args, &hdr);
+        encode_putfh(xdr, args->fh, &hdr);
+        encode_getdevicelist(xdr, args, &hdr);
+        encode_nops(&hdr);
+}
+
+/*
  * Encode GETDEVICEINFO request
  */
 static void nfs4_xdr_enc_getdeviceinfo(struct rpc_rqst *req,
@@ -5268,6 +5325,53 @@ out_overflow:
 }
 
 #if defined(CONFIG_NFS_V4_1)
+/*
+ * TODO: Need to handle case when EOF != true;
+ */
+static int decode_getdevicelist(struct xdr_stream *xdr,
+                                struct pnfs_devicelist *res)
+{
+        __be32 *p;
+        int status, i;
+        struct nfs_writeverf verftemp;
+
+        status = decode_op_hdr(xdr, OP_GETDEVICELIST);
+        if (status)
+                return status;
+
+        p = xdr_inline_decode(xdr, 8 + 8 + 4);
+        if (unlikely(!p))
+                goto out_overflow;
+
+        /* TODO: Skip cookie for now */
+        p += 2;
+
+        /* Read verifier */
+        p = xdr_decode_opaque_fixed(p, verftemp.verifier, 8);
+
+        res->num_devs = be32_to_cpup(p);
+
+        dprintk("%s: num_dev %d\n", __func__, res->num_devs);
+
+        if (res->num_devs > NFS4_PNFS_GETDEVLIST_MAXNUM) {
+                printk(KERN_ERR "%s too many result dev_num %u\n",
+                                __func__, res->num_devs);
+                return -EIO;
+        }
+
+        p = xdr_inline_decode(xdr,
+                              res->num_devs * NFS4_DEVICEID4_SIZE + 4);
+        if (unlikely(!p))
+                goto out_overflow;
+        for (i = 0; i < res->num_devs; i++)
+                p = xdr_decode_opaque_fixed(p, res->dev_id[i].data,
+                                            NFS4_DEVICEID4_SIZE);
+        res->eof = be32_to_cpup(p);
+        return 0;
+out_overflow:
+        print_overflow_msg(__func__, xdr);
+        return -EIO;
+}
 
 static int decode_getdeviceinfo(struct xdr_stream *xdr,
                                 struct pnfs_device *pdev)
@@ -6542,6 +6646,32 @@ static int nfs4_xdr_dec_reclaim_complete(struct rpc_rqst *rqstp,
 }
 
 /*
+ * Decode GETDEVICELIST response
+ */
+static int nfs4_xdr_dec_getdevicelist(struct rpc_rqst *rqstp,
+                                      struct xdr_stream *xdr,
+                                      struct nfs4_getdevicelist_res *res)
+{
+        struct compound_hdr hdr;
+        int status;
+
+        dprintk("encoding getdevicelist!\n");
+
+        status = decode_compound_hdr(xdr, &hdr);
+        if (status != 0)
+                goto out;
+        status = decode_sequence(xdr, &res->seq_res, rqstp);
+        if (status != 0)
+                goto out;
+        status = decode_putfh(xdr);
+        if (status != 0)
+                goto out;
+        status = decode_getdevicelist(xdr, res->devlist);
+out:
+        return status;
+}
+
+/*
  * Decode GETDEVINFO response
  */
 static int nfs4_xdr_dec_getdeviceinfo(struct rpc_rqst *rqstp,
@@ -6908,6 +7038,7 @@ struct rpc_procinfo	nfs4_procedures[] = {
         PROC(SECINFO_NO_NAME,   enc_secinfo_no_name,    dec_secinfo_no_name),
         PROC(TEST_STATEID,      enc_test_stateid,       dec_test_stateid),
         PROC(FREE_STATEID,      enc_free_stateid,       dec_free_stateid),
+        PROC(GETDEVICELIST,     enc_getdevicelist,      dec_getdevicelist),
 #endif /* CONFIG_NFS_V4_1 */
 };
 
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index b94f874886ca..7074394944a9 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -135,14 +135,26 @@ struct pnfs_device {
         unsigned int  layout_type;
         unsigned int  mincount;
         struct page **pages;
+        void          *area;
         unsigned int  pgbase;
         unsigned int  pglen;
 };
 
+#define NFS4_PNFS_GETDEVLIST_MAXNUM 16
+
+struct pnfs_devicelist {
+        unsigned int            eof;
+        unsigned int            num_devs;
+        struct nfs4_deviceid    dev_id[NFS4_PNFS_GETDEVLIST_MAXNUM];
+};
+
 extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
 extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
 
 /* nfs4proc.c */
+extern int nfs4_proc_getdevicelist(struct nfs_server *server,
+                                   const struct nfs_fh *fh,
+                                   struct pnfs_devicelist *devlist);
 extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
                                    struct pnfs_device *dev);
 extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index a3c4bc800dce..76f99e8714f3 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -566,6 +566,7 @@ enum {
         NFSPROC4_CLNT_SECINFO_NO_NAME,
         NFSPROC4_CLNT_TEST_STATEID,
         NFSPROC4_CLNT_FREE_STATEID,
+        NFSPROC4_CLNT_GETDEVICELIST,
 };
 
 /* nfs41 types */
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index feb312716c07..21f333eae3c8 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -235,6 +235,17 @@ struct nfs4_layoutget {
         gfp_t gfp_flags;
 };
 
+struct nfs4_getdevicelist_args {
+        const struct nfs_fh *fh;
+        u32 layoutclass;
+        struct nfs4_sequence_args seq_args;
+};
+
+struct nfs4_getdevicelist_res {
+        struct pnfs_devicelist *devlist;
+        struct nfs4_sequence_res seq_res;
+};
+
 struct nfs4_getdeviceinfo_args {
         struct pnfs_device *pdev;
         struct nfs4_sequence_args seq_args;