NFSv.2/pnfs Add a LAYOUTSTATS rpc function

Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

8 files changed, 205 insertions, 3 deletions

diff --git a/fs/nfs/nfs42.h b/fs/nfs/nfs42.h
index 7afb8947dfdf..ff66ae700b89 100644
--- a/fs/nfs/nfs42.h
+++ b/fs/nfs/nfs42.h
@@ -5,11 +5,18 @@
 #ifndef __LINUX_FS_NFS_NFS4_2_H
 #define __LINUX_FS_NFS_NFS4_2_H
 
+/*
+ * FIXME:  four LAYOUTSTATS calls per compound at most! Do we need to support
+ * more? Need to consider not to pre-alloc too much for a compound.
+ */
+#define PNFS_LAYOUTSTATS_MAXDEV (4)
+
 /* nfs4.2proc.c */
 int nfs42_proc_allocate(struct file *, loff_t, loff_t);
 int nfs42_proc_deallocate(struct file *, loff_t, loff_t);
 loff_t nfs42_proc_llseek(struct file *, loff_t, int);
-
+int nfs42_proc_layoutstats_generic(struct nfs_server *,
+                                   struct nfs42_layoutstat_data *);
 /* nfs4.2xdr.h */
 extern struct rpc_procinfo nfs4_2_procedures[];
 
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 3a9e75235f30..ac929685350b 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -165,3 +165,30 @@ loff_t nfs42_proc_llseek(struct file *filep, loff_t offset, int whence)
 
         return vfs_setpos(filep, res.sr_offset, inode->i_sb->s_maxbytes);
 }
+
+static const struct rpc_call_ops nfs42_layoutstat_ops = {
+};
+
+int nfs42_proc_layoutstats_generic(struct nfs_server *server,
+                                   struct nfs42_layoutstat_data *data)
+{
+        struct rpc_message msg = {
+                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTSTATS],
+                .rpc_argp = &data->args,
+                .rpc_resp = &data->res,
+        };
+        struct rpc_task_setup task_setup = {
+                .rpc_client = server->client,
+                .rpc_message = &msg,
+                .callback_ops = &nfs42_layoutstat_ops,
+                .callback_data = data,
+                .flags = RPC_TASK_ASYNC,
+        };
+        struct rpc_task *task;
+
+        nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 0);
+        task = rpc_run_task(&task_setup);
+        if (IS_ERR(task))
+                return PTR_ERR(task);
+        return 0;
+}
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 1a25b27248f2..9aae0205ef11 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -4,6 +4,8 @@
 #ifndef __LINUX_FS_NFS_NFS4_2XDR_H
 #define __LINUX_FS_NFS_NFS4_2XDR_H
 
+#include "nfs42.h"
+
 #define encode_fallocate_maxsz          (encode_stateid_maxsz + \
                                          2 /* offset */ + \
                                          2 /* length */)
@@ -22,6 +24,16 @@
                                          1 /* whence */ + \
                                          2 /* offset */ + \
                                          2 /* length */)
+#define encode_io_info_maxsz            4
+#define encode_layoutstats_maxsz        (op_decode_hdr_maxsz + \
+                                        2 /* offset */ + \
+                                        2 /* length */ + \
+                                        encode_stateid_maxsz + \
+                                        encode_io_info_maxsz + \
+                                        encode_io_info_maxsz + \
+                                        1 /* opaque devaddr4 length */ + \
+                                        XDR_QUADLEN(PNFS_LAYOUTSTATS_MAXSIZE))
+#define decode_layoutstats_maxsz        (op_decode_hdr_maxsz)
 
 #define NFS4_enc_allocate_sz            (compound_encode_hdr_maxsz + \
                                          encode_putfh_maxsz + \
@@ -45,6 +57,14 @@
 #define NFS4_dec_seek_sz                (compound_decode_hdr_maxsz + \
                                          decode_putfh_maxsz + \
                                          decode_seek_maxsz)
+#define NFS4_enc_layoutstats_sz         (compound_encode_hdr_maxsz + \
+                                         encode_sequence_maxsz + \
+                                         encode_putfh_maxsz + \
+                                         PNFS_LAYOUTSTATS_MAXDEV * encode_layoutstats_maxsz)
+#define NFS4_dec_layoutstats_sz         (compound_decode_hdr_maxsz + \
+                                         decode_sequence_maxsz + \
+                                         decode_putfh_maxsz + \
+                                         PNFS_LAYOUTSTATS_MAXDEV * decode_layoutstats_maxsz)
 
 
 static void encode_fallocate(struct xdr_stream *xdr,
@@ -81,6 +101,33 @@ static void encode_seek(struct xdr_stream *xdr,
         encode_uint32(xdr, args->sa_what);
 }
 
+static void encode_layoutstats(struct xdr_stream *xdr,
+                               struct nfs42_layoutstat_args *args,
+                               struct nfs42_layoutstat_devinfo *devinfo,
+                               struct compound_hdr *hdr)
+{
+        __be32 *p;
+
+        encode_op_hdr(xdr, OP_LAYOUTSTATS, decode_layoutstats_maxsz, hdr);
+        p = reserve_space(xdr, 8 + 8);
+        p = xdr_encode_hyper(p, devinfo->offset);
+        p = xdr_encode_hyper(p, devinfo->length);
+        encode_nfs4_stateid(xdr, &args->stateid);
+        p = reserve_space(xdr, 4*8 + NFS4_DEVICEID4_SIZE + 4);
+        p = xdr_encode_hyper(p, devinfo->read_count);
+        p = xdr_encode_hyper(p, devinfo->read_bytes);
+        p = xdr_encode_hyper(p, devinfo->write_count);
+        p = xdr_encode_hyper(p, devinfo->write_bytes);
+        p = xdr_encode_opaque_fixed(p, devinfo->dev_id.data,
+                        NFS4_DEVICEID4_SIZE);
+        /* Encode layoutupdate4 */
+        *p++ = cpu_to_be32(devinfo->layout_type);
+        if (devinfo->layoutstats_encode != NULL)
+                devinfo->layoutstats_encode(xdr, args, devinfo);
+        else
+                encode_uint32(xdr, 0);
+}
+
 /*
  * Encode ALLOCATE request
  */
@@ -137,6 +184,28 @@ static void nfs4_xdr_enc_seek(struct rpc_rqst *req,
         encode_nops(&hdr);
 }
 
+/*
+ * Encode LAYOUTSTATS request
+ */
+static void nfs4_xdr_enc_layoutstats(struct rpc_rqst *req,
+                                     struct xdr_stream *xdr,
+                                     struct nfs42_layoutstat_args *args)
+{
+        int i;
+
+        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);
+        WARN_ON(args->num_dev > PNFS_LAYOUTSTATS_MAXDEV);
+        for (i = 0; i < args->num_dev; i++)
+                encode_layoutstats(xdr, args, &args->devinfo[i], &hdr);
+        encode_nops(&hdr);
+}
+
 static int decode_allocate(struct xdr_stream *xdr, struct nfs42_falloc_res *res)
 {
         return decode_op_hdr(xdr, OP_ALLOCATE);
@@ -169,6 +238,28 @@ out_overflow:
         return -EIO;
 }
 
+static int decode_layoutstats(struct xdr_stream *xdr,
+                              struct nfs42_layoutstat_res *res)
+{
+        int status;
+        __be32 *p;
+
+        status = decode_op_hdr(xdr, OP_LAYOUTSTATS);
+        if (status)
+                return status;
+
+        p = xdr_inline_decode(xdr, 4);
+        if (unlikely(!p))
+                goto out_overflow;
+
+        res->rpc_status = be32_to_cpup(p++);
+        return 0;
+
+out_overflow:
+        print_overflow_msg(__func__, xdr);
+        return -EIO;
+}
+
 /*
  * Decode ALLOCATE request
  */
@@ -246,4 +337,35 @@ static int nfs4_xdr_dec_seek(struct rpc_rqst *rqstp,
 out:
         return status;
 }
+
+/*
+ * Decode LAYOUTSTATS request
+ */
+static int nfs4_xdr_dec_layoutstats(struct rpc_rqst *rqstp,
+                                    struct xdr_stream *xdr,
+                                    struct nfs42_layoutstat_res *res)
+{
+        struct compound_hdr hdr;
+        int status, i;
+
+        status = decode_compound_hdr(xdr, &hdr);
+        if (status)
+                goto out;
+        status = decode_sequence(xdr, &res->seq_res, rqstp);
+        if (status)
+                goto out;
+        status = decode_putfh(xdr);
+        if (status)
+                goto out;
+        WARN_ON(res->num_dev > PNFS_LAYOUTSTATS_MAXDEV);
+        for (i = 0; i < res->num_dev; i++) {
+                status = decode_layoutstats(xdr, res);
+                if (status)
+                        goto out;
+        }
+out:
+        res->rpc_status = status;
+        return status;
+}
+
 #endif /* __LINUX_FS_NFS_NFS4_2XDR_H */
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index fdef424b0cd3..ea3bee919a76 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -233,6 +233,7 @@ extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception
 extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
                           struct rpc_message *, struct nfs4_sequence_args *,
                           struct nfs4_sequence_res *, int);
+extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int);
 extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *);
 extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, struct rpc_cred *);
 extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index e9cd45f1d60f..643ce3a91b22 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -476,8 +476,8 @@ struct nfs4_call_sync_data {
         struct nfs4_sequence_res *seq_res;
 };
 
-static void nfs4_init_sequence(struct nfs4_sequence_args *args,
-                               struct nfs4_sequence_res *res, int cache_reply)
+void nfs4_init_sequence(struct nfs4_sequence_args *args,
+                        struct nfs4_sequence_res *res, int cache_reply)
 {
         args->sa_slot = NULL;
         args->sa_cache_this = cache_reply;
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index a07555d6968c..558cd65dbdb7 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -7431,6 +7431,7 @@ struct rpc_procinfo	nfs4_procedures[] = {
         PROC(SEEK,              enc_seek,               dec_seek),
         PROC(ALLOCATE,          enc_allocate,           dec_allocate),
         PROC(DEALLOCATE,        enc_deallocate,         dec_deallocate),
+        PROC(LAYOUTSTATS,       enc_layoutstats,        dec_layoutstats),
 #endif /* CONFIG_NFS_V4_2 */
 };
 
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 32201c269890..b8e72aad919c 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -500,6 +500,7 @@ enum {
         NFSPROC4_CLNT_SEEK,
         NFSPROC4_CLNT_ALLOCATE,
         NFSPROC4_CLNT_DEALLOCATE,
+        NFSPROC4_CLNT_LAYOUTSTATS,
 };
 
 /* nfs41 types */
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index c959e7eb5bd4..7bbe50504211 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -316,6 +316,49 @@ struct nfs4_layoutreturn {
         int rpc_status;
 };
 
+#define PNFS_LAYOUTSTATS_MAXSIZE 256
+
+struct nfs42_layoutstat_args;
+struct nfs42_layoutstat_devinfo;
+typedef void (*layoutstats_encode_t)(struct xdr_stream *,
+                struct nfs42_layoutstat_args *,
+                struct nfs42_layoutstat_devinfo *);
+
+/* Per file per deviceid layoutstats */
+struct nfs42_layoutstat_devinfo {
+        struct nfs4_deviceid dev_id;
+        __u64 offset;
+        __u64 length;
+        __u64 read_count;
+        __u64 read_bytes;
+        __u64 write_count;
+        __u64 write_bytes;
+        __u32 layout_type;
+        layoutstats_encode_t layoutstats_encode;
+        void *layout_private;
+};
+
+struct nfs42_layoutstat_args {
+        struct nfs4_sequence_args seq_args;
+        struct nfs_fh *fh;
+        struct inode *inode;
+        nfs4_stateid stateid;
+        int num_dev;
+        struct nfs42_layoutstat_devinfo *devinfo;
+};
+
+struct nfs42_layoutstat_res {
+        struct nfs4_sequence_res seq_res;
+        int num_dev;
+        int rpc_status;
+};
+
+struct nfs42_layoutstat_data {
+        struct inode *inode;
+        struct nfs42_layoutstat_args args;
+        struct nfs42_layoutstat_res res;
+};
+
 struct stateowner_id {
         __u64   create_time;
         __u32   uniquifier;