[PATCH v3] NFS: Implement SEEK

Anna Schumaker
2014-09-26T17:58:52Z

From: Anna Schumaker <Anna.Schumaker@netapp.com>

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>
---
fs/nfs/Makefile | 1 +
fs/nfs/inode.c | 2 +
fs/nfs/nfs42.h | 14 +++++++
fs/nfs/nfs42proc.c | 69 +++++++++++++++++++++++++++++++++
fs/nfs/nfs42xdr.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++
fs/nfs/nfs4_fs.h | 3 ++
fs/nfs/nfs4file.c | 25 ++++++++++++
fs/nfs/nfs4proc.c | 4 +-
fs/nfs/nfs4xdr.c | 7 ++++
include/linux/nfs4.h | 3 ++
include/linux/nfs_fs_sb.h | 1 +
include/linux/nfs_xdr.h | 19 +++++++++
12 files changed, 244 insertions(+), 2 deletions(-)
create mode 100644 fs/nfs/nfs42.h
create mode 100644 fs/nfs/nfs42proc.c
create mode 100644 fs/nfs/nfs42xdr.c

diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index 4782e08..04cb830 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -28,6 +28,7 @@ nfsv4-y := nfs4proc.o nfs4xdr.o nfs4state.o nfs4renewd.o nfs4super.o nfs4file.o
nfsv4-$(CONFIG_NFS_USE_LEGACY_DNS) += cache_lib.o
nfsv4-$(CONFIG_SYSCTL) += nfs4sysctl.o
nfsv4-$(CONFIG_NFS_V4_1) += pnfs.o pnfs_dev.o
+nfsv4-$(CONFIG_NFS_V4_2) += nfs42proc.o

obj-$(CONFIG_PNFS_FILE_LAYOUT) += filelayout/
obj-$(CONFIG_PNFS_OBJLAYOUT) += objlayout/
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 141c9f4..6388a59 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -718,6 +718,7 @@ struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
kfree(new);
return res;
}
+EXPORT_SYMBOL_GPL(nfs_get_lock_context);

void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
{
@@ -730,6 +731,7 @@ void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
spin_unlock(&inode->i_lock);
kfree(l_ctx);
}
+EXPORT_SYMBOL_GPL(nfs_put_lock_context);

/**
* nfs_close_context - Common close_context() routine NFSv2/v3
diff --git a/fs/nfs/nfs42.h b/fs/nfs/nfs42.h
new file mode 100644
index 0000000..d10333a
--- /dev/null
+++ b/fs/nfs/nfs42.h
@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
+ */
+
+#ifndef __LINUX_FS_NFS_NFS4_2_H
+#define __LINUX_FS_NFS_NFS4_2_H
+
+/* nfs4.2proc.c */
+loff_t nfs42_proc_llseek(struct file *, loff_t, int);
+
+/* nfs4.2xdr.h */
+extern struct rpc_procinfo nfs4_2_procedures[];
+
+#endif /* __LINUX_FS_NFS_NFS4_2_H */
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
new file mode 100644
index 0000000..0886f1d
--- /dev/null
+++ b/fs/nfs/nfs42proc.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
+ */
+#include <linux/fs.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/nfs.h>
+#include <linux/nfs3.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_xdr.h>
+#include <linux/nfs_fs.h>
+#include "nfs4_fs.h"
+#include "nfs42.h"
+
+static int nfs42_set_rw_stateid(nfs4_stateid *dst, struct file *file,
+ fmode_t fmode)
+{
+ struct nfs_open_context *open;
+ struct nfs_lock_context *lock;
+ int ret;
+
+ open = get_nfs_open_context(nfs_file_open_context(file));
+ lock = nfs_get_lock_context(open);
+ if (IS_ERR(lock)) {
+ put_nfs_open_context(open);
+ return PTR_ERR(lock);
+ }
+
+ ret = nfs4_set_rw_stateid(dst, open, lock, fmode);
+
+ nfs_put_lock_context(lock);
+ put_nfs_open_context(open);
+ return ret;
+}
+
+loff_t nfs42_proc_llseek(struct file *filep, loff_t offset, int whence)
+{
+ struct inode *inode = file_inode(filep);
+ struct nfs42_seek_args args = {
+ .sa_fh = NFS_FH(inode),
+ .sa_offset = offset,
+ .sa_what = (whence == SEEK_HOLE) ?
+ NFS4_CONTENT_HOLE : NFS4_CONTENT_DATA,
+ };
+ struct nfs42_seek_res res;
+ struct rpc_message msg = {
+ .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SEEK],
+ .rpc_argp = &args,
+ .rpc_resp = &res,
+ };
+ struct nfs_server *server = NFS_SERVER(inode);
+ int status;
+
+ if (!(server->caps & NFS_CAP_SEEK))
+ return -ENOTSUPP;
+
+ status = nfs42_set_rw_stateid(&args.sa_stateid, filep, FMODE_READ);
+ if (status)
+ return status;
+
+ nfs_wb_all(inode);
+ status = nfs4_call_sync(server->client, server, &msg,
+ &args.seq_args, &res.seq_res, 0);
+ if (status == -ENOTSUPP)
+ server->caps &= ~NFS_CAP_SEEK;
+ if (status)
+ return status;
+
+ return vfs_setpos(filep, res.sr_offset, inode->i_sb->s_maxbytes);
+}
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
new file mode 100644
index 0000000..c90469b
--- /dev/null
+++ b/fs/nfs/nfs42xdr.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
+ */
+#ifndef __LINUX_FS_NFS_NFS4_2XDR_H
+#define __LINUX_FS_NFS_NFS4_2XDR_H
+
+#define encode_seek_maxsz (op_encode_hdr_maxsz + \
+ encode_stateid_maxsz + \
+ 2 /* offset */ + \
+ 1 /* whence */)
+#define decode_seek_maxsz (op_decode_hdr_maxsz + \
+ 1 /* eof */ + \
+ 1 /* whence */ + \
+ 2 /* offset */ + \
+ 2 /* length */)
+
+#define NFS4_enc_seek_sz (compound_encode_hdr_maxsz + \
+ encode_putfh_maxsz + \
+ encode_seek_maxsz)
+#define NFS4_dec_seek_sz (compound_decode_hdr_maxsz + \
+ decode_putfh_maxsz + \
+ decode_seek_maxsz)
+
+
+static void encode_seek(struct xdr_stream *xdr,
+ struct nfs42_seek_args *args,
+ struct compound_hdr *hdr)
+{
+ encode_op_hdr(xdr, OP_SEEK, decode_seek_maxsz, hdr);
+ encode_nfs4_stateid(xdr, &args->sa_stateid);
+ encode_uint64(xdr, args->sa_offset);
+ encode_uint32(xdr, args->sa_what);
+}
+
+/*
+ * Encode SEEK request
+ */
+static void nfs4_xdr_enc_seek(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ struct nfs42_seek_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->sa_fh, &hdr);
+ encode_seek(xdr, args, &hdr);
+ encode_nops(&hdr);
+}
+
+static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
+{
+ int status;
+ __be32 *p;
+
+ status = decode_op_hdr(xdr, OP_SEEK);
+ if (status)
+ return status;
+
+ p = xdr_inline_decode(xdr, 4 + 8);
+ if (unlikely(!p))
+ goto out_overflow;
+
+ res->sr_eof = be32_to_cpup(p++);
+ p = xdr_decode_hyper(p, &res->sr_offset);
+ return 0;
+
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+}
+
+/*
+ * Decode SEEK request
+ */
+static int nfs4_xdr_dec_seek(struct rpc_rqst *rqstp,
+ struct xdr_stream *xdr,
+ struct nfs42_seek_res *res)
+{
+ 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_seek(xdr, res);
+out:
+ return status;
+}
+#endif /* __LINUX_FS_NFS_NFS4_2XDR_H */
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index a8b855a..be6cac3 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -226,6 +226,9 @@ int nfs4_replace_transport(struct nfs_server *server,
const struct nfs4_fs_locations *locations);

/* nfs4proc.c */
+extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
+ struct rpc_message *, 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/nfs4file.c b/fs/nfs/nfs4file.c
index a816f06..4dffa3a 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -8,6 +8,10 @@
#include "fscache.h"
#include "pnfs.h"

+#ifdef CONFIG_NFS_V4_2
+#include "nfs42.h"
+#endif
+
#define NFSDBG_FACILITY NFSDBG_FILE

static int
@@ -115,8 +119,29 @@ nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
return ret;
}

+#ifdef CONFIG_NFS_V4_2
+static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
+{
+ loff_t ret;
+
+ switch (whence) {
+ case SEEK_HOLE:
+ case SEEK_DATA:
+ ret = nfs42_proc_llseek(filep, offset, whence);
+ if (ret != -ENOTSUPP)
+ return ret;
+ default:
+ return nfs_file_llseek(filep, offset, whence);
+ }
+}
+#endif /* CONFIG_NFS_V4_2 */
+
const struct file_operations nfs4_file_operations = {
+#ifdef CONFIG_NFS_V4_2
+ .llseek = nfs4_file_llseek,
+#else
.llseek = nfs_file_llseek,
+#endif
.read = new_sync_read,
.write = new_sync_write,
.read_iter = nfs_file_read,
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 549d3b0..ba5eda3 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -885,7 +885,6 @@ static int nfs4_call_sync_sequence(struct rpc_clnt *clnt,
return ret;
}

-static
int nfs4_call_sync(struct rpc_clnt *clnt,
struct nfs_server *server,
struct rpc_message *msg,
@@ -8431,7 +8430,8 @@ static const struct nfs4_minor_version_ops nfs_v4_2_minor_ops = {
| NFS_CAP_CHANGE_ATTR
| NFS_CAP_POSIX_LOCK
| NFS_CAP_STATEID_NFSV41
- | NFS_CAP_ATOMIC_OPEN_V1,
+ | NFS_CAP_ATOMIC_OPEN_V1
+ | NFS_CAP_SEEK,
.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 005d03c..206c08a 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -7321,6 +7321,10 @@ nfs4_stat_to_errno(int stat)
return -stat;
}

+#ifdef CONFIG_NFS_V4_2
+#include "nfs42xdr.c"
+#endif /* CONFIG_NFS_V4_2 */
+
#define PROC(proc, argtype, restype) \
[NFSPROC4_CLNT_##proc] = { \
.p_proc = NFSPROC4_COMPOUND, \
@@ -7388,6 +7392,9 @@ struct rpc_procinfo nfs4_procedures[] = {
enc_bind_conn_to_session, dec_bind_conn_to_session),
PROC(DESTROY_CLIENTID, enc_destroy_clientid, dec_destroy_clientid),
#endif /* CONFIG_NFS_V4_1 */
+#ifdef CONFIG_NFS_V4_2
+ PROC(SEEK, enc_seek, dec_seek),
+#endif /* CONFIG_NFS_V4_2 */
};

const struct rpc_version nfs_version4 = {
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 026b0c0..356acc2 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 922be2e..a32ba0d 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 6951c7d..983876f 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1231,6 +1231,25 @@ 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)
--
2.1.0