2020-08-17 16:55:45

by Anna Schumaker

[permalink] [raw]
Subject: [PATCH v4 04/10] NFS: Add READ_PLUS data segment support

From: Anna Schumaker <[email protected]>

This patch adds client support for decoding a single NFS4_CONTENT_DATA
segment returned by the server. This is the simplest implementation
possible, since it does not account for any hole segments in the reply.

Signed-off-by: Anna Schumaker <[email protected]>
---
fs/nfs/nfs42xdr.c | 141 ++++++++++++++++++++++++++++++++++++++
fs/nfs/nfs4proc.c | 43 +++++++++++-
fs/nfs/nfs4xdr.c | 1 +
include/linux/nfs4.h | 2 +-
include/linux/nfs_fs_sb.h | 1 +
include/linux/nfs_xdr.h | 2 +-
6 files changed, 185 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index c03f3246d6c5..055a944d043d 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -45,6 +45,15 @@
#define encode_deallocate_maxsz (op_encode_hdr_maxsz + \
encode_fallocate_maxsz)
#define decode_deallocate_maxsz (op_decode_hdr_maxsz)
+#define encode_read_plus_maxsz (op_encode_hdr_maxsz + \
+ encode_stateid_maxsz + 3)
+#define NFS42_READ_PLUS_SEGMENT_SIZE (1 /* data_content4 */ + \
+ 2 /* data_info4.di_offset */ + \
+ 2 /* data_info4.di_length */)
+#define decode_read_plus_maxsz (op_decode_hdr_maxsz + \
+ 1 /* rpr_eof */ + \
+ 1 /* rpr_contents count */ + \
+ NFS42_READ_PLUS_SEGMENT_SIZE)
#define encode_seek_maxsz (op_encode_hdr_maxsz + \
encode_stateid_maxsz + \
2 /* offset */ + \
@@ -128,6 +137,14 @@
decode_putfh_maxsz + \
decode_deallocate_maxsz + \
decode_getattr_maxsz)
+#define NFS4_enc_read_plus_sz (compound_encode_hdr_maxsz + \
+ encode_sequence_maxsz + \
+ encode_putfh_maxsz + \
+ encode_read_plus_maxsz)
+#define NFS4_dec_read_plus_sz (compound_decode_hdr_maxsz + \
+ decode_sequence_maxsz + \
+ decode_putfh_maxsz + \
+ decode_read_plus_maxsz)
#define NFS4_enc_seek_sz (compound_encode_hdr_maxsz + \
encode_sequence_maxsz + \
encode_putfh_maxsz + \
@@ -252,6 +269,16 @@ static void encode_deallocate(struct xdr_stream *xdr,
encode_fallocate(xdr, args);
}

+static void encode_read_plus(struct xdr_stream *xdr,
+ const struct nfs_pgio_args *args,
+ struct compound_hdr *hdr)
+{
+ encode_op_hdr(xdr, OP_READ_PLUS, decode_read_plus_maxsz, hdr);
+ encode_nfs4_stateid(xdr, &args->stateid);
+ encode_uint64(xdr, args->offset);
+ encode_uint32(xdr, args->count);
+}
+
static void encode_seek(struct xdr_stream *xdr,
const struct nfs42_seek_args *args,
struct compound_hdr *hdr)
@@ -446,6 +473,28 @@ static void nfs4_xdr_enc_deallocate(struct rpc_rqst *req,
encode_nops(&hdr);
}

+/*
+ * Encode READ_PLUS request
+ */
+static void nfs4_xdr_enc_read_plus(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ const void *data)
+{
+ const struct nfs_pgio_args *args = data;
+ 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_read_plus(xdr, args, &hdr);
+
+ rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+ args->count, hdr.replen);
+ encode_nops(&hdr);
+}
+
/*
* Encode SEEK request
*/
@@ -694,6 +743,71 @@ static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *re
return decode_op_hdr(xdr, OP_DEALLOCATE);
}

+static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *res,
+ uint32_t *eof)
+{
+ uint32_t count, recvd;
+ uint64_t offset;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 8 + 4);
+ if (unlikely(!p))
+ return -EIO;
+
+ p = xdr_decode_hyper(p, &offset);
+ count = be32_to_cpup(p);
+ recvd = xdr_read_pages(xdr, count);
+ res->count += recvd;
+
+ if (count > recvd) {
+ dprintk("NFS: server cheating in read reply: "
+ "count %u > recvd %u\n", count, recvd);
+ *eof = 0;
+ return 1;
+ }
+
+ return 0;
+}
+
+static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
+{
+ uint32_t eof, segments, type;
+ int status;
+ __be32 *p;
+
+ status = decode_op_hdr(xdr, OP_READ_PLUS);
+ if (status)
+ return status;
+
+ p = xdr_inline_decode(xdr, 4 + 4);
+ if (unlikely(!p))
+ return -EIO;
+
+ eof = be32_to_cpup(p++);
+ segments = be32_to_cpup(p++);
+ if (segments == 0)
+ goto out;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ return -EIO;
+
+ type = be32_to_cpup(p++);
+ if (type == NFS4_CONTENT_DATA)
+ status = decode_read_plus_data(xdr, res, &eof);
+ else
+ return -EINVAL;
+
+ if (status)
+ return status;
+ if (segments > 1)
+ eof = 0;
+
+out:
+ res->eof = eof;
+ return 0;
+}
+
static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
{
int status;
@@ -870,6 +984,33 @@ static int nfs4_xdr_dec_deallocate(struct rpc_rqst *rqstp,
return status;
}

+/*
+ * Decode READ_PLUS request
+ */
+static int nfs4_xdr_dec_read_plus(struct rpc_rqst *rqstp,
+ struct xdr_stream *xdr,
+ void *data)
+{
+ struct nfs_pgio_res *res = data;
+ struct compound_hdr hdr;
+ int status;
+
+ 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;
+ status = decode_read_plus(xdr, res);
+ if (!status)
+ status = res->count;
+out:
+ return status;
+}
+
/*
* Decode SEEK request
*/
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2e2dac29a9e9..509198eb968e 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -69,6 +69,10 @@

#include "nfs4trace.h"

+#ifdef CONFIG_NFS_V4_2
+#include "nfs42.h"
+#endif /* CONFIG_NFS_V4_2 */
+
#define NFSDBG_FACILITY NFSDBG_PROC

#define NFS4_BITMASK_SZ 3
@@ -5226,28 +5230,60 @@ static bool nfs4_read_stateid_changed(struct rpc_task *task,
return true;
}

+static bool nfs4_read_plus_not_supported(struct rpc_task *task,
+ struct nfs_pgio_header *hdr)
+{
+ struct nfs_server *server = NFS_SERVER(hdr->inode);
+ struct rpc_message *msg = &task->tk_msg;
+
+ if (msg->rpc_proc == &nfs4_procedures[NFSPROC4_CLNT_READ_PLUS] &&
+ server->caps & NFS_CAP_READ_PLUS && task->tk_status == -ENOTSUPP) {
+ server->caps &= ~NFS_CAP_READ_PLUS;
+ msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+ rpc_restart_call_prepare(task);
+ return true;
+ }
+ return false;
+}
+
static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
{
-
dprintk("--> %s\n", __func__);

if (!nfs4_sequence_done(task, &hdr->res.seq_res))
return -EAGAIN;
if (nfs4_read_stateid_changed(task, &hdr->args))
return -EAGAIN;
+ if (nfs4_read_plus_not_supported(task, hdr))
+ return -EAGAIN;
if (task->tk_status > 0)
nfs_invalidate_atime(hdr->inode);
return hdr->pgio_done_cb ? hdr->pgio_done_cb(task, hdr) :
nfs4_read_done_cb(task, hdr);
}

+#ifdef CONFIG_NFS_V4_2
+static void nfs42_read_plus_support(struct nfs_server *server, struct rpc_message *msg)
+{
+ if (server->caps & NFS_CAP_READ_PLUS)
+ msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ_PLUS];
+ else
+ msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+}
+#else
+static void nfs42_read_plus_support(struct nfs_server *server, struct rpc_message *msg)
+{
+ msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+}
+#endif /* CONFIG_NFS_V4_2 */
+
static void nfs4_proc_read_setup(struct nfs_pgio_header *hdr,
struct rpc_message *msg)
{
hdr->timestamp = jiffies;
if (!hdr->pgio_done_cb)
hdr->pgio_done_cb = nfs4_read_done_cb;
- msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+ nfs42_read_plus_support(NFS_SERVER(hdr->inode), msg);
nfs4_init_sequence(&hdr->args.seq_args, &hdr->res.seq_res, 0, 0);
}

@@ -10006,7 +10042,8 @@ static const struct nfs4_minor_version_ops nfs_v4_2_minor_ops = {
| NFS_CAP_SEEK
| NFS_CAP_LAYOUTSTATS
| NFS_CAP_CLONE
- | NFS_CAP_LAYOUTERROR,
+ | NFS_CAP_LAYOUTERROR
+ | NFS_CAP_READ_PLUS,
.init_client = nfs41_init_client,
.shutdown_client = nfs41_shutdown_client,
.match_stateid = nfs41_match_stateid,
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 6742646d4feb..80d9d55a48c2 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -7580,6 +7580,7 @@ const struct rpc_procinfo nfs4_procedures[] = {
PROC42(COPY_NOTIFY, enc_copy_notify, dec_copy_notify),
PROC(LOOKUPP, enc_lookupp, dec_lookupp),
PROC42(LAYOUTERROR, enc_layouterror, dec_layouterror),
+ PROC42(READ_PLUS, enc_read_plus, dec_read_plus),
};

static unsigned int nfs_version4_counts[ARRAY_SIZE(nfs4_procedures)];
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 4dba3c948932..4bf75b56758c 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -540,8 +540,8 @@ enum {

NFSPROC4_CLNT_LOOKUPP,
NFSPROC4_CLNT_LAYOUTERROR,
-
NFSPROC4_CLNT_COPY_NOTIFY,
+ NFSPROC4_CLNT_READ_PLUS,
};

/* nfs41 types */
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 465fa98258a3..11248c5a7b24 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -281,5 +281,6 @@ struct nfs_server {
#define NFS_CAP_OFFLOAD_CANCEL (1U << 25)
#define NFS_CAP_LAYOUTERROR (1U << 26)
#define NFS_CAP_COPY_NOTIFY (1U << 27)
+#define NFS_CAP_READ_PLUS (1U << 28)

#endif
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 5fd0a9ef425f..6da54d010421 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -656,7 +656,7 @@ struct nfs_pgio_args {
struct nfs_pgio_res {
struct nfs4_sequence_res seq_res;
struct nfs_fattr * fattr;
- __u32 count;
+ __u64 count;
__u32 op_status;
union {
struct {
--
2.28.0