NFS client updates for Linux 3.18

Highlights include:
 
 Stable fixes:
 - Fix an uninitialised pointer Oops in the writeback error path
 - Fix a bogus warning (and early exit from the loop) in nfs_generic_pgio
 
 Features:
 - Add NFSv4.2 SEEK feature and client support for lseek(SEEK_HOLE/SEEK_DATA)
 
 Other fixes:
 - pnfs: replace broken pnfs_put_lseg_async
 - Remove dead prototype for nfs4_insert_deviceid_node
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Merge tag 'nfs-for-3.18-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - fix an uninitialised pointer Oops in the writeback error path
   - fix a bogus warning (and early exit from the loop) in nfs_generic_pgio()

  Features:
   - Add NFSv4.2 SEEK feature and client support for lseek(SEEK_HOLE/SEEK_DATA)

  Other fixes:
   - pnfs: replace broken pnfs_put_lseg_async
   - Remove dead prototype for nfs4_insert_deviceid_node"

* tag 'nfs-for-3.18-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Fix a bogus warning in nfs_generic_pgio
  NFS: Fix an uninitialised pointer Oops in the writeback error path
  NFSv4.1/pnfs: replace broken pnfs_put_lseg_async
  NFSv4: Remove dead prototype for nfs4_insert_deviceid_node()
  NFS: Implement SEEK

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/

fs/nfs/filelayout/filelayout.c

@@ -1031,7 +1031,7 @@ filelayout_clear_request_commit(struct nfs_page *req,
 	}
 out:
 	nfs_request_remove_commit_list(req, cinfo);
-	pnfs_put_lseg_async(freeme);
+	pnfs_put_lseg_locked(freeme);
 }
 
 static void

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

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 */

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);
+}

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 */

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);

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,

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,
@@ -8409,7 +8408,8 @@ static const struct nfs4_minor_version_ops nfs_v4_1_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,

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 = {

fs/nfs/pagelist.c

@@ -526,7 +526,8 @@ EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
  */
 void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
 {
-	put_nfs_open_context(hdr->args.context);
+	if (hdr->args.context)
+		put_nfs_open_context(hdr->args.context);
 	if (hdr->page_array.pagevec != hdr->page_array.page_array)
 		kfree(hdr->page_array.pagevec);
 }
@@ -751,12 +752,11 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
 		nfs_list_remove_request(req);
 		nfs_list_add_request(req, &hdr->pages);
 
-		if (WARN_ON_ONCE(pageused >= pagecount))
-			return nfs_pgio_error(desc, hdr);
-
 		if (!last_page || last_page != req->wb_page) {
-			*pages++ = last_page = req->wb_page;
 			pageused++;
+			if (pageused > pagecount)
+				break;
+			*pages++ = last_page = req->wb_page;
 		}
 	}
 	if (WARN_ON_ONCE(pageused != pagecount))

fs/nfs/pnfs.c

@@ -361,22 +361,43 @@ pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 }
 EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 
-static void pnfs_put_lseg_async_work(struct work_struct *work)
+static void pnfs_free_lseg_async_work(struct work_struct *work)
 {
 	struct pnfs_layout_segment *lseg;
+	struct pnfs_layout_hdr *lo;
 
 	lseg = container_of(work, struct pnfs_layout_segment, pls_work);
+	lo = lseg->pls_layout;
 
-	pnfs_put_lseg(lseg);
+	pnfs_free_lseg(lseg);
+	pnfs_put_layout_hdr(lo);
+}
+
+static void pnfs_free_lseg_async(struct pnfs_layout_segment *lseg)
+{
+	INIT_WORK(&lseg->pls_work, pnfs_free_lseg_async_work);
+	schedule_work(&lseg->pls_work);
 }
 
 void
-pnfs_put_lseg_async(struct pnfs_layout_segment *lseg)
+pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
 {
-	INIT_WORK(&lseg->pls_work, pnfs_put_lseg_async_work);
+	if (!lseg)
-	schedule_work(&lseg->pls_work);
+		return;
+
+	assert_spin_locked(&lseg->pls_layout->plh_inode->i_lock);
+
+	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
+		atomic_read(&lseg->pls_refcount),
+		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
+	if (atomic_dec_and_test(&lseg->pls_refcount)) {
+		struct pnfs_layout_hdr *lo = lseg->pls_layout;
+		pnfs_get_layout_hdr(lo);
+		pnfs_layout_remove_lseg(lo, lseg);
+		pnfs_free_lseg_async(lseg);
+	}
 }
-EXPORT_SYMBOL_GPL(pnfs_put_lseg_async);
+EXPORT_SYMBOL_GPL(pnfs_put_lseg_locked);
 
 static u64
 end_offset(u64 start, u64 len)

fs/nfs/pnfs.h

@@ -190,7 +190,7 @@ extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);
 /* pnfs.c */
 void pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo);
 void pnfs_put_lseg(struct pnfs_layout_segment *lseg);
-void pnfs_put_lseg_async(struct pnfs_layout_segment *lseg);
+void pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg);
 
 void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32);
 void unset_pnfs_layoutdriver(struct nfs_server *);
@@ -270,7 +270,6 @@ nfs4_find_get_deviceid(struct nfs_server *server,
 void nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
 void nfs4_init_deviceid_node(struct nfs4_deviceid_node *, struct nfs_server *,
 			     const struct nfs4_deviceid *);
-struct nfs4_deviceid_node *nfs4_insert_deviceid_node(struct nfs4_deviceid_node *);
 bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
 void nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node);
 bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
@@ -446,10 +445,6 @@ static inline void pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 {
 }
 
-static inline void pnfs_put_lseg_async(struct pnfs_layout_segment *lseg)
-{
-}
-
 static inline int pnfs_return_layout(struct inode *ino)
 {
 	return 0;

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 */

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

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)