[PATCH v11 13/20] nfs: add "localio" support

Mike Snitzer
2024-07-02T16:28:50Z

From: Weston Andros Adamson <dros@primarydata.com>

Add client support for bypassing NFS for localhost reads, writes, and
commits. This is only useful when the client and the server are
running on the same host.

nfs_local_probe() is stubbed out, later commits will enable client and
server handshake via a Linux-only LOCALIO auxiliary RPC protocol.

This has dynamic binding with the nfsd module (via nfs_localio module
which is part of nfs_common). Localio will only work if nfsd is
already loaded.

The "localio_enabled" nfs kernel module parameter can be used to
disable and enable the ability to use localio support.

CONFIG_NFS_LOCALIO controls the client enablement.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
fs/nfs/Kconfig | 14 +
fs/nfs/Makefile | 1 +
fs/nfs/client.c | 3 +
fs/nfs/inode.c | 4 +
fs/nfs/internal.h | 51 +++
fs/nfs/localio.c | 661 ++++++++++++++++++++++++++++++++++++++
fs/nfs/nfstrace.h | 61 ++++
fs/nfs/pagelist.c | 3 +
fs/nfs/write.c | 3 +
include/linux/nfs.h | 2 +
include/linux/nfs_fs.h | 2 +
include/linux/nfs_fs_sb.h | 1 +
12 files changed, 806 insertions(+)
create mode 100644 fs/nfs/localio.c

diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index 57249f040dfc..311ae8bc587f 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -86,6 +86,20 @@ config NFS_V4

If unsure, say Y.

+config NFS_LOCALIO
+ tristate "NFS client support for the LOCALIO auxiliary protocol"
+ depends on NFS_V3 || NFS_V4
+ select NFS_COMMON_LOCALIO_SUPPORT
+ help
+ Some NFS servers support an auxiliary NFS LOCALIO protocol
+ that is not an official part of the NFS version 3 or 4 protocol.
+
+ This option enables support for the LOCALIO protocol in the
+ kernel's NFS client. Enable this to bypass using the NFS
+ protocol when issuing reads, writes and commits to the server.
+
+ If unsure, say N.
+
config NFS_SWAP
bool "Provide swap over NFS support"
default n
diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index 5f6db37f461e..9fb2f2cac87e 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -13,6 +13,7 @@ nfs-y := client.o dir.o file.o getroot.o inode.o super.o \
nfs-$(CONFIG_ROOT_NFS) += nfsroot.o
nfs-$(CONFIG_SYSCTL) += sysctl.o
nfs-$(CONFIG_NFS_FSCACHE) += fscache.o
+nfs-$(CONFIG_NFS_LOCALIO) += localio.o

obj-$(CONFIG_NFS_V2) += nfsv2.o
nfsv2-y := nfs2super.o proc.o nfs2xdr.o
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index bcdf8d42cbc7..1300c388f971 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -241,6 +241,8 @@ static void pnfs_init_server(struct nfs_server *server)
*/
void nfs_free_client(struct nfs_client *clp)
{
+ nfs_local_disable(clp);
+
/* -EIO all pending I/O */
if (!IS_ERR(clp->cl_rpcclient))
rpc_shutdown_client(clp->cl_rpcclient);
@@ -432,6 +434,7 @@ struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
list_add_tail(&new->cl_share_link,
&nn->nfs_client_list);
spin_unlock(&nn->nfs_client_lock);
+ nfs_local_probe(new);
return rpc_ops->init_client(new, cl_init);
}

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index acef52ecb1bb..f9923cbf6058 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -39,6 +39,7 @@
#include <linux/slab.h>
#include <linux/compat.h>
#include <linux/freezer.h>
+#include <linux/file.h>
#include <linux/uaccess.h>
#include <linux/iversion.h>

@@ -1053,6 +1054,7 @@ struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
ctx->lock_context.open_context = ctx;
INIT_LIST_HEAD(&ctx->list);
ctx->mdsthreshold = NULL;
+ ctx->local_filp = NULL;
return ctx;
}
EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
@@ -1084,6 +1086,8 @@ static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
nfs_sb_deactive(sb);
put_rpccred(rcu_dereference_protected(ctx->ll_cred, 1));
kfree(ctx->mdsthreshold);
+ if (!IS_ERR_OR_NULL(ctx->local_filp))
+ fput(ctx->local_filp);
kfree_rcu(ctx, rcu_head);
}

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 958c8de072e2..d352040e3232 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -451,6 +451,57 @@ extern void nfs_set_cache_invalid(struct inode *inode, unsigned long flags);
extern bool nfs_check_cache_invalid(struct inode *, unsigned long);
extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode);

+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+/* localio.c */
+extern void nfs_local_disable(struct nfs_client *);
+extern void nfs_local_probe(struct nfs_client *);
+extern struct file *nfs_local_open_fh(struct nfs_client *, const struct cred *,
+ struct nfs_fh *, const fmode_t);
+extern struct file *nfs_local_file_open(struct nfs_client *clp,
+ const struct cred *cred,
+ struct nfs_fh *fh,
+ struct nfs_open_context *ctx);
+extern int nfs_local_doio(struct nfs_client *, struct file *,
+ struct nfs_pgio_header *,
+ const struct rpc_call_ops *);
+extern int nfs_local_commit(struct file *, struct nfs_commit_data *,
+ const struct rpc_call_ops *, int);
+extern bool nfs_server_is_local(const struct nfs_client *clp);
+
+#else
+static inline void nfs_local_disable(struct nfs_client *clp) {}
+static inline void nfs_local_probe(struct nfs_client *clp) {}
+static inline struct file *nfs_local_open_fh(struct nfs_client *clp,
+ const struct cred *cred,
+ struct nfs_fh *fh,
+ const fmode_t mode)
+{
+ return ERR_PTR(-EINVAL);
+}
+static inline struct file *nfs_local_file_open(struct nfs_client *clp,
+ const struct cred *cred,
+ struct nfs_fh *fh,
+ struct nfs_open_context *ctx)
+{
+ return NULL;
+}
+static inline int nfs_local_doio(struct nfs_client *clp, struct file *filep,
+ struct nfs_pgio_header *hdr,
+ const struct rpc_call_ops *call_ops)
+{
+ return -EINVAL;
+}
+static inline int nfs_local_commit(struct file *filep, struct nfs_commit_data *data,
+ const struct rpc_call_ops *call_ops, int how)
+{
+ return -EINVAL;
+}
+static inline bool nfs_server_is_local(const struct nfs_client *clp)
+{
+ return false;
+}
+#endif /* CONFIG_NFS_LOCALIO */
+
/* super.c */
extern const struct super_operations nfs_sops;
bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
new file mode 100644
index 000000000000..5fd286e92df4
--- /dev/null
+++ b/fs/nfs/localio.c
@@ -0,0 +1,661 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * NFS client support for local clients to bypass network stack
+ *
+ * Copyright (C) 2014 Weston Andros Adamson <dros@primarydata.com>
+ * Copyright (C) 2019 Trond Myklebust <trond.myklebust@hammerspace.com>
+ * Copyright (C) 2024 Mike Snitzer <snitzer@hammerspace.com>
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/vfs.h>
+#include <linux/file.h>
+#include <linux/inet.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/inetdevice.h>
+#include <net/addrconf.h>
+#include <linux/module.h>
+#include <linux/bvec.h>
+
+#include <linux/nfs.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_xdr.h>
+
+#include "internal.h"
+#include "pnfs.h"
+#include "nfstrace.h"
+
+#define NFSDBG_FACILITY NFSDBG_VFS
+
+struct nfs_local_kiocb {
+ struct kiocb kiocb;
+ struct bio_vec *bvec;
+ struct nfs_pgio_header *hdr;
+ struct work_struct work;
+};
+
+struct nfs_local_fsync_ctx {
+ struct file *filp;
+ struct nfs_commit_data *data;
+ struct work_struct work;
+ struct kref kref;
+ struct completion *done;
+};
+static void nfs_local_fsync_work(struct work_struct *work);
+
+/*
+ * We need to translate between nfs status return values and
+ * the local errno values which may not be the same.
+ */
+static struct {
+ __u32 stat;
+ int errno;
+} nfs_errtbl[] = {
+ { NFS4_OK, 0 },
+ { NFS4ERR_PERM, -EPERM },
+ { NFS4ERR_NOENT, -ENOENT },
+ { NFS4ERR_IO, -EIO },
+ { NFS4ERR_NXIO, -ENXIO },
+ { NFS4ERR_FBIG, -E2BIG },
+ { NFS4ERR_STALE, -EBADF },
+ { NFS4ERR_ACCESS, -EACCES },
+ { NFS4ERR_EXIST, -EEXIST },
+ { NFS4ERR_XDEV, -EXDEV },
+ { NFS4ERR_MLINK, -EMLINK },
+ { NFS4ERR_NOTDIR, -ENOTDIR },
+ { NFS4ERR_ISDIR, -EISDIR },
+ { NFS4ERR_INVAL, -EINVAL },
+ { NFS4ERR_FBIG, -EFBIG },
+ { NFS4ERR_NOSPC, -ENOSPC },
+ { NFS4ERR_ROFS, -EROFS },
+ { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG },
+ { NFS4ERR_NOTEMPTY, -ENOTEMPTY },
+ { NFS4ERR_DQUOT, -EDQUOT },
+ { NFS4ERR_STALE, -ESTALE },
+ { NFS4ERR_STALE, -EOPENSTALE },
+ { NFS4ERR_DELAY, -ETIMEDOUT },
+ { NFS4ERR_DELAY, -ERESTARTSYS },
+ { NFS4ERR_DELAY, -EAGAIN },
+ { NFS4ERR_DELAY, -ENOMEM },
+ { NFS4ERR_IO, -ETXTBSY },
+ { NFS4ERR_IO, -EBUSY },
+ { NFS4ERR_BADHANDLE, -EBADHANDLE },
+ { NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
+ { NFS4ERR_NOTSUPP, -EOPNOTSUPP },
+ { NFS4ERR_TOOSMALL, -ETOOSMALL },
+ { NFS4ERR_SERVERFAULT, -ESERVERFAULT },
+ { NFS4ERR_SERVERFAULT, -ENFILE },
+ { NFS4ERR_IO, -EREMOTEIO },
+ { NFS4ERR_IO, -EUCLEAN },
+ { NFS4ERR_PERM, -ENOKEY },
+ { NFS4ERR_BADTYPE, -EBADTYPE },
+ { NFS4ERR_SYMLINK, -ELOOP },
+ { NFS4ERR_DEADLOCK, -EDEADLK },
+};
+
+/*
+ * Convert an NFS error code to a local one.
+ * This one is used jointly by NFSv2 and NFSv3.
+ */
+static __u32
+nfs4errno(int errno)
+{
+ unsigned int i;
+ for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
+ if (nfs_errtbl[i].errno == errno)
+ return nfs_errtbl[i].stat;
+ }
+ /* If we cannot translate the error, the recovery routines should
+ * handle it.
+ * Note: remaining NFSv4 error codes have values > 10000, so should
+ * not conflict with native Linux error codes.
+ */
+ return NFS4ERR_SERVERFAULT;
+}
+
+static bool localio_enabled __read_mostly = true;
+module_param(localio_enabled, bool, 0644);
+
+bool nfs_server_is_local(const struct nfs_client *clp)
+{
+ return test_bit(NFS_CS_LOCAL_IO, &clp->cl_flags) != 0 &&
+ localio_enabled;
+}
+EXPORT_SYMBOL_GPL(nfs_server_is_local);
+
+/*
+ * nfs_local_enable - enable local i/o for an nfs_client
+ */
+static __maybe_unused void nfs_local_enable(struct nfs_client *clp,
+ struct net *net)
+{
+ if (READ_ONCE(clp->nfsd_open_local_fh)) {
+ set_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
+ clp->cl_nfssvc_net = net;
+ trace_nfs_local_enable(clp);
+ }
+}
+
+/*
+ * nfs_local_disable - disable local i/o for an nfs_client
+ */
+void nfs_local_disable(struct nfs_client *clp)
+{
+ if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
+ trace_nfs_local_disable(clp);
+ clp->cl_nfssvc_net = NULL;
+ }
+}
+
+/*
+ * nfs_local_probe - probe local i/o support for an nfs_server and nfs_client
+ */
+void nfs_local_probe(struct nfs_client *clp)
+{
+}
+EXPORT_SYMBOL_GPL(nfs_local_probe);
+
+/*
+ * nfs_local_open_fh - open a local filehandle
+ *
+ * Returns a pointer to a struct file or an ERR_PTR
+ */
+struct file *
+nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
+ struct nfs_fh *fh, const fmode_t mode)
+{
+ struct file *filp;
+ int status;
+
+ if (mode & ~(FMODE_READ | FMODE_WRITE))
+ return ERR_PTR(-EINVAL);
+
+ status = clp->nfsd_open_local_fh(clp->cl_nfssvc_net, clp->cl_rpcclient,
+ cred, fh, mode, &filp);
+ if (status < 0) {
+ trace_nfs_local_open_fh(fh, mode, status);
+ switch (status) {
+ case -ENXIO:
+ nfs_local_disable(clp);
+ fallthrough;
+ case -ETIMEDOUT:
+ status = -EAGAIN;
+ }
+ filp = ERR_PTR(status);
+ }
+ return filp;
+}
+EXPORT_SYMBOL_GPL(nfs_local_open_fh);
+
+static struct bio_vec *
+nfs_bvec_alloc_and_import_pagevec(struct page **pagevec,
+ unsigned int npages, gfp_t flags)
+{
+ struct bio_vec *bvec, *p;
+
+ bvec = kmalloc_array(npages, sizeof(*bvec), flags);
+ if (bvec != NULL) {
+ for (p = bvec; npages > 0; p++, pagevec++, npages--) {
+ p->bv_page = *pagevec;
+ p->bv_len = PAGE_SIZE;
+ p->bv_offset = 0;
+ }
+ }
+ return bvec;
+}
+
+static void
+nfs_local_iocb_free(struct nfs_local_kiocb *iocb)
+{
+ kfree(iocb->bvec);
+ kfree(iocb);
+}
+
+static struct nfs_local_kiocb *
+nfs_local_iocb_alloc(struct nfs_pgio_header *hdr, struct file *filp,
+ gfp_t flags)
+{
+ struct nfs_local_kiocb *iocb;
+
+ iocb = kmalloc(sizeof(*iocb), flags);
+ if (iocb == NULL)
+ return NULL;
+ iocb->bvec = nfs_bvec_alloc_and_import_pagevec(hdr->page_array.pagevec,
+ hdr->page_array.npages, flags);
+ if (iocb->bvec == NULL) {
+ kfree(iocb);
+ return NULL;
+ }
+ init_sync_kiocb(&iocb->kiocb, filp);
+ iocb->kiocb.ki_pos = hdr->args.offset;
+ iocb->hdr = hdr;
+ iocb->kiocb.ki_flags &= ~IOCB_APPEND;
+ return iocb;
+}
+
+static void
+nfs_local_iter_init(struct iov_iter *i, struct nfs_local_kiocb *iocb, int dir)
+{
+ struct nfs_pgio_header *hdr = iocb->hdr;
+
+ iov_iter_bvec(i, dir, iocb->bvec, hdr->page_array.npages,
+ hdr->args.count + hdr->args.pgbase);
+ if (hdr->args.pgbase != 0)
+ iov_iter_advance(i, hdr->args.pgbase);
+}
+
+static void
+nfs_local_hdr_release(struct nfs_pgio_header *hdr,
+ const struct rpc_call_ops *call_ops)
+{
+ call_ops->rpc_call_done(&hdr->task, hdr);
+ call_ops->rpc_release(hdr);
+}
+
+static void
+nfs_local_pgio_init(struct nfs_pgio_header *hdr,
+ const struct rpc_call_ops *call_ops)
+{
+ hdr->task.tk_ops = call_ops;
+ if (!hdr->task.tk_start)
+ hdr->task.tk_start = ktime_get();
+}
+
+static void
+nfs_local_pgio_done(struct nfs_pgio_header *hdr, long status)
+{
+ if (status >= 0) {
+ hdr->res.count = status;
+ hdr->res.op_status = NFS4_OK;
+ hdr->task.tk_status = 0;
+ } else {
+ hdr->res.op_status = nfs4errno(status);
+ hdr->task.tk_status = status;
+ }
+}
+
+static void
+nfs_local_pgio_release(struct nfs_local_kiocb *iocb)
+{
+ struct nfs_pgio_header *hdr = iocb->hdr;
+
+ fput(iocb->kiocb.ki_filp);
+ nfs_local_iocb_free(iocb);
+ nfs_local_hdr_release(hdr, hdr->task.tk_ops);
+}
+
+static void
+nfs_local_read_done(struct nfs_local_kiocb *iocb, long status)
+{
+ struct nfs_pgio_header *hdr = iocb->hdr;
+ struct file *filp = iocb->kiocb.ki_filp;
+
+ nfs_local_pgio_done(hdr, status);
+
+ if (hdr->res.count != hdr->args.count ||
+ hdr->args.offset + hdr->res.count >= i_size_read(file_inode(filp)))
+ hdr->res.eof = true;
+
+ dprintk("%s: read %ld bytes eof %d.\n", __func__,
+ status > 0 ? status : 0, hdr->res.eof);
+}
+
+static int
+nfs_do_local_read(struct nfs_pgio_header *hdr, struct file *filp,
+ const struct rpc_call_ops *call_ops)
+{
+ struct nfs_local_kiocb *iocb;
+ struct iov_iter iter;
+ ssize_t status;
+
+ dprintk("%s: vfs_read count=%u pos=%llu\n",
+ __func__, hdr->args.count, hdr->args.offset);
+
+ iocb = nfs_local_iocb_alloc(hdr, filp, GFP_KERNEL);
+ if (iocb == NULL)
+ return -ENOMEM;
+ nfs_local_iter_init(&iter, iocb, READ);
+
+ nfs_local_pgio_init(hdr, call_ops);
+ hdr->res.eof = false;
+
+ status = filp->f_op->read_iter(&iocb->kiocb, &iter);
+ WARN_ON_ONCE(status == -EIOCBQUEUED);
+
+ nfs_local_read_done(iocb, status);
+ nfs_local_pgio_release(iocb);
+
+ return 0;
+}
+
+static void
+nfs_copy_boot_verifier(struct nfs_write_verifier *verifier, struct inode *inode)
+{
+ struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+ u32 *verf = (u32 *)verifier->data;
+ int seq = 0;
+
+ do {
+ read_seqbegin_or_lock(&clp->cl_boot_lock, &seq);
+ verf[0] = (u32)clp->cl_nfssvc_boot.tv_sec;
+ verf[1] = (u32)clp->cl_nfssvc_boot.tv_nsec;
+ } while (need_seqretry(&clp->cl_boot_lock, seq));
+ done_seqretry(&clp->cl_boot_lock, seq);
+}
+
+static void
+nfs_reset_boot_verifier(struct inode *inode)
+{
+ struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+
+ write_seqlock(&clp->cl_boot_lock);
+ ktime_get_real_ts64(&clp->cl_nfssvc_boot);
+ write_sequnlock(&clp->cl_boot_lock);
+}
+
+static void
+nfs_set_local_verifier(struct inode *inode,
+ struct nfs_writeverf *verf,
+ enum nfs3_stable_how how)
+{
+
+ nfs_copy_boot_verifier(&verf->verifier, inode);
+ verf->committed = how;
+}
+
+static void nfs_local_vfs_getattr(struct nfs_local_kiocb *iocb)
+{
+ struct kstat stat;
+ struct file *filp = iocb->kiocb.ki_filp;
+ struct nfs_pgio_header *hdr = iocb->hdr;
+ struct nfs_fattr *fattr = hdr->res.fattr;
+
+ if (unlikely(!fattr) || vfs_getattr(&filp->f_path, &stat,
+ STATX_INO |
+ STATX_ATIME |
+ STATX_MTIME |
+ STATX_CTIME |
+ STATX_SIZE |
+ STATX_BLOCKS,
+ AT_STATX_SYNC_AS_STAT))
+ return;
+
+ fattr->valid = (NFS_ATTR_FATTR_FILEID |
+ NFS_ATTR_FATTR_CHANGE |
+ NFS_ATTR_FATTR_SIZE |
+ NFS_ATTR_FATTR_ATIME |
+ NFS_ATTR_FATTR_MTIME |
+ NFS_ATTR_FATTR_CTIME |
+ NFS_ATTR_FATTR_SPACE_USED);
+
+ fattr->fileid = stat.ino;
+ fattr->size = stat.size;
+ fattr->atime = stat.atime;
+ fattr->mtime = stat.mtime;
+ fattr->ctime = stat.ctime;
+ fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
+ fattr->du.nfs3.used = stat.blocks << 9;
+}
+
+static void
+nfs_local_write_done(struct nfs_local_kiocb *iocb, long status)
+{
+ struct nfs_pgio_header *hdr = iocb->hdr;
+ struct inode *inode = hdr->inode;
+
+ dprintk("%s: wrote %ld bytes.\n", __func__, status > 0 ? status : 0);
+
+ /* Handle short writes as if they are ENOSPC */
+ if (status > 0 && status < hdr->args.count) {
+ hdr->mds_offset += status;
+ hdr->args.offset += status;
+ hdr->args.pgbase += status;
+ hdr->args.count -= status;
+ nfs_set_pgio_error(hdr, -ENOSPC, hdr->args.offset);
+ status = -ENOSPC;
+ }
+ if (status < 0)
+ nfs_reset_boot_verifier(inode);
+ else if (nfs_should_remove_suid(inode)) {
+ /* Deal with the suid/sgid bit corner case */
+ spin_lock(&inode->i_lock);
+ nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
+ spin_unlock(&inode->i_lock);
+ }
+ nfs_local_pgio_done(hdr, status);
+}
+
+static int
+nfs_do_local_write(struct nfs_pgio_header *hdr, struct file *filp,
+ const struct rpc_call_ops *call_ops)
+{
+ struct nfs_local_kiocb *iocb;
+ struct iov_iter iter;
+ ssize_t status;
+
+ dprintk("%s: vfs_write count=%u pos=%llu %s\n",
+ __func__, hdr->args.count, hdr->args.offset,
+ (hdr->args.stable == NFS_UNSTABLE) ? "unstable" : "stable");
+
+ iocb = nfs_local_iocb_alloc(hdr, filp, GFP_NOIO);
+ if (iocb == NULL)
+ return -ENOMEM;
+ nfs_local_iter_init(&iter, iocb, WRITE);
+
+ switch (hdr->args.stable) {
+ default:
+ break;
+ case NFS_DATA_SYNC:
+ iocb->kiocb.ki_flags |= IOCB_DSYNC;
+ break;
+ case NFS_FILE_SYNC:
+ iocb->kiocb.ki_flags |= IOCB_DSYNC|IOCB_SYNC;
+ }
+ nfs_local_pgio_init(hdr, call_ops);
+
+ nfs_set_local_verifier(hdr->inode, hdr->res.verf, hdr->args.stable);
+
+ file_start_write(filp);
+ status = filp->f_op->write_iter(&iocb->kiocb, &iter);
+ file_end_write(filp);
+ WARN_ON_ONCE(status == -EIOCBQUEUED);
+
+ nfs_local_write_done(iocb, status);
+ nfs_local_vfs_getattr(iocb);
+ nfs_local_pgio_release(iocb);
+
+ return 0;
+}
+
+static struct file *
+nfs_local_file_open_cached(struct nfs_client *clp, const struct cred *cred,
+ struct nfs_fh *fh, struct nfs_open_context *ctx)
+{
+ struct file *filp = ctx->local_filp;
+
+ if (!filp) {
+ struct file *new = nfs_local_open_fh(clp, cred, fh, ctx->mode);
+ if (IS_ERR_OR_NULL(new))
+ return NULL;
+ /* try to put this one in the slot */
+ filp = cmpxchg(&ctx->local_filp, NULL, new);
+ if (filp != NULL)
+ fput(new);
+ else
+ filp = new;
+ }
+ return get_file(filp);
+}
+
+struct file *
+nfs_local_file_open(struct nfs_client *clp, const struct cred *cred,
+ struct nfs_fh *fh, struct nfs_open_context *ctx)
+{
+ if (!nfs_server_is_local(clp))
+ return NULL;
+ return nfs_local_file_open_cached(clp, cred, fh, ctx);
+}
+
+int
+nfs_local_doio(struct nfs_client *clp, struct file *filp,
+ struct nfs_pgio_header *hdr,
+ const struct rpc_call_ops *call_ops)
+{
+ int status = 0;
+
+ if (!hdr->args.count)
+ goto out_fput;
+ /* Don't support filesystems without read_iter/write_iter */
+ if (!filp->f_op->read_iter || !filp->f_op->write_iter) {
+ nfs_local_disable(clp);
+ status = -EAGAIN;
+ goto out_fput;
+ }
+
+ switch (hdr->rw_mode) {
+ case FMODE_READ:
+ status = nfs_do_local_read(hdr, filp, call_ops);
+ break;
+ case FMODE_WRITE:
+ status = nfs_do_local_write(hdr, filp, call_ops);
+ break;
+ default:
+ dprintk("%s: invalid mode: %d\n", __func__,
+ hdr->rw_mode);
+ status = -EINVAL;
+ }
+out_fput:
+ if (status != 0) {
+ fput(filp);
+ hdr->task.tk_status = status;
+ nfs_local_hdr_release(hdr, call_ops);
+ }
+ return status;
+}
+
+static void
+nfs_local_init_commit(struct nfs_commit_data *data,
+ const struct rpc_call_ops *call_ops)
+{
+ data->task.tk_ops = call_ops;
+}
+
+static int
+nfs_local_run_commit(struct file *filp, struct nfs_commit_data *data)
+{
+ loff_t start = data->args.offset;
+ loff_t end = LLONG_MAX;
+
+ if (data->args.count > 0) {
+ end = start + data->args.count - 1;
+ if (end < start)
+ end = LLONG_MAX;
+ }
+
+ dprintk("%s: commit %llu - %llu\n", __func__, start, end);
+ return vfs_fsync_range(filp, start, end, 0);
+}
+
+static void
+nfs_local_commit_done(struct nfs_commit_data *data, int status)
+{
+ if (status >= 0) {
+ nfs_set_local_verifier(data->inode,
+ data->res.verf,
+ NFS_FILE_SYNC);
+ data->res.op_status = NFS4_OK;
+ data->task.tk_status = 0;
+ } else {
+ nfs_reset_boot_verifier(data->inode);
+ data->res.op_status = nfs4errno(status);
+ data->task.tk_status = status;
+ }
+}
+
+static void
+nfs_local_release_commit_data(struct file *filp,
+ struct nfs_commit_data *data,
+ const struct rpc_call_ops *call_ops)
+{
+ fput(filp);
+ call_ops->rpc_call_done(&data->task, data);
+ call_ops->rpc_release(data);
+}
+
+static struct nfs_local_fsync_ctx *
+nfs_local_fsync_ctx_alloc(struct nfs_commit_data *data, struct file *filp,
+ gfp_t flags)
+{
+ struct nfs_local_fsync_ctx *ctx = kmalloc(sizeof(*ctx), flags);
+
+ if (ctx != NULL) {
+ ctx->filp = filp;
+ ctx->data = data;
+ INIT_WORK(&ctx->work, nfs_local_fsync_work);
+ kref_init(&ctx->kref);
+ ctx->done = NULL;
+ }
+ return ctx;
+}
+
+static void
+nfs_local_fsync_ctx_kref_free(struct kref *kref)
+{
+ kfree(container_of(kref, struct nfs_local_fsync_ctx, kref));
+}
+
+static void
+nfs_local_fsync_ctx_put(struct nfs_local_fsync_ctx *ctx)
+{
+ kref_put(&ctx->kref, nfs_local_fsync_ctx_kref_free);
+}
+
+static void
+nfs_local_fsync_ctx_free(struct nfs_local_fsync_ctx *ctx)
+{
+ nfs_local_release_commit_data(ctx->filp, ctx->data,
+ ctx->data->task.tk_ops);
+ nfs_local_fsync_ctx_put(ctx);
+}
+
+static void
+nfs_local_fsync_work(struct work_struct *work)
+{
+ struct nfs_local_fsync_ctx *ctx;
+ int status;
+
+ ctx = container_of(work, struct nfs_local_fsync_ctx, work);
+
+ status = nfs_local_run_commit(ctx->filp, ctx->data);
+ nfs_local_commit_done(ctx->data, status);
+ if (ctx->done != NULL)
+ complete(ctx->done);
+ nfs_local_fsync_ctx_free(ctx);
+}
+
+int
+nfs_local_commit(struct file *filp, struct nfs_commit_data *data,
+ const struct rpc_call_ops *call_ops, int how)
+{
+ struct nfs_local_fsync_ctx *ctx;
+
+ ctx = nfs_local_fsync_ctx_alloc(data, filp, GFP_KERNEL);
+ if (!ctx) {
+ nfs_local_commit_done(data, -ENOMEM);
+ nfs_local_release_commit_data(filp, data, call_ops);
+ return -ENOMEM;
+ }
+
+ nfs_local_init_commit(data, call_ops);
+ kref_get(&ctx->kref);
+ if (how & FLUSH_SYNC) {
+ DECLARE_COMPLETION_ONSTACK(done);
+ ctx->done = &done;
+ queue_work(nfsiod_workqueue, &ctx->work);
+ wait_for_completion(&done);
+ } else
+ queue_work(nfsiod_workqueue, &ctx->work);
+ nfs_local_fsync_ctx_put(ctx);
+ return 0;
+}
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index 1e710654af11..95a2c19a9172 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -1681,6 +1681,67 @@ TRACE_EVENT(nfs_mount_path,
TP_printk("path='%s'", __get_str(path))
);

+TRACE_EVENT(nfs_local_open_fh,
+ TP_PROTO(
+ const struct nfs_fh *fh,
+ fmode_t fmode,
+ int error
+ ),
+
+ TP_ARGS(fh, fmode, error),
+
+ TP_STRUCT__entry(
+ __field(int, error)
+ __field(u32, fhandle)
+ __field(unsigned int, fmode)
+ ),
+
+ TP_fast_assign(
+ __entry->error = error;
+ __entry->fhandle = nfs_fhandle_hash(fh);
+ __entry->fmode = (__force unsigned int)fmode;
+ ),
+
+ TP_printk(
+ "error=%d fhandle=0x%08x mode=%s",
+ __entry->error,
+ __entry->fhandle,
+ show_fs_fmode_flags(__entry->fmode)
+ )
+);
+
+DECLARE_EVENT_CLASS(nfs_local_client_event,
+ TP_PROTO(
+ const struct nfs_client *clp
+ ),
+
+ TP_ARGS(clp),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, protocol)
+ __string(server, clp->cl_hostname)
+ ),
+
+ TP_fast_assign(
+ __entry->protocol = clp->rpc_ops->version;
+ __assign_str(server);
+ ),
+
+ TP_printk(
+ "server=%s NFSv%u", __get_str(server), __entry->protocol
+ )
+);
+
+#define DEFINE_NFS_LOCAL_CLIENT_EVENT(name) \
+ DEFINE_EVENT(nfs_local_client_event, name, \
+ TP_PROTO( \
+ const struct nfs_client *clp \
+ ), \
+ TP_ARGS(clp))
+
+DEFINE_NFS_LOCAL_CLIENT_EVENT(nfs_local_enable);
+DEFINE_NFS_LOCAL_CLIENT_EVENT(nfs_local_disable);
+
DECLARE_EVENT_CLASS(nfs_xdr_event,
TP_PROTO(
const struct xdr_stream *xdr,
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 727d3b80e897..7b7dbbefee03 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -879,6 +879,9 @@ int nfs_initiate_pgio(struct nfs_pageio_descriptor *desc,
hdr->args.count,
(unsigned long long)hdr->args.offset);

+ if (localio)
+ return nfs_local_doio(clp, localio, hdr, call_ops);
+
task = rpc_run_task(&task_setup_data);
if (IS_ERR(task))
return PTR_ERR(task);
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 267bed2a4ceb..b29b0fd5431f 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1700,6 +1700,9 @@ int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,

dprintk("NFS: initiated commit call\n");

+ if (localio)
+ return nfs_local_commit(localio, data, call_ops, how);
+
task = rpc_run_task(&task_setup_data);
if (IS_ERR(task))
return PTR_ERR(task);
diff --git a/include/linux/nfs.h b/include/linux/nfs.h
index b1e00349f3ed..036f6b0ed94d 100644
--- a/include/linux/nfs.h
+++ b/include/linux/nfs.h
@@ -8,6 +8,8 @@
#ifndef _LINUX_NFS_H
#define _LINUX_NFS_H

+#include <linux/cred.h>
+#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/string.h>
#include <linux/crc32.h>
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 039898d70954..a0bb947fdd1d 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -96,6 +96,8 @@ struct nfs_open_context {
struct list_head list;
struct nfs4_threshold *mdsthreshold;
struct rcu_head rcu_head;
+
+ struct file *local_filp;
};

struct nfs_open_dir_context {
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index e58e706a6503..4290c550a049 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -50,6 +50,7 @@ struct nfs_client {
#define NFS_CS_DS 7 /* - Server is a DS */
#define NFS_CS_REUSEPORT 8 /* - reuse src port on reconnect */
#define NFS_CS_PNFS 9 /* - Server used for pnfs */
+#define NFS_CS_LOCAL_IO 10 /* - client is local */
struct sockaddr_storage cl_addr; /* server identifier */
size_t cl_addrlen;
char * cl_hostname; /* hostname of server */
--
2.44.0