[for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Mike Snitzer]

Hi,

All available here:
https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next

Changes since v2:
- switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
  NULL.
- removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
- revised the NFS v3 probe patch to use a new nfsv3.ko modparam
  'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
  LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
  'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
- added "Module Parameters" section to localio.rst

All review appreciated, thanks.
Mike

Mike Snitzer (14):
  nfs/localio: add direct IO enablement with sync and async IO support
  nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
  nfs_common: rename functions that invalidate LOCALIO nfs_clients
  nfs_common: move localio_lock to new lock member of nfs_uuid_t
  nfs: cache all open LOCALIO nfsd_file(s) in client
  nfsd: update percpu_ref to manage references on nfsd_net
  nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
  nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
  nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
  nfs_common: track all open nfsd_files per LOCALIO nfs_client
  nfs_common: add nfs_localio trace events
  nfs/localio: remove redundant code and simplify LOCALIO enablement
  nfs: probe for LOCALIO when v4 client reconnects to server
  nfs: probe for LOCALIO when v3 client reconnects to server

 Documentation/filesystems/nfs/localio.rst |  98 +++++----
 fs/nfs/client.c                           |   6 +-
 fs/nfs/direct.c                           |   1 +
 fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
 fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
 fs/nfs/inode.c                            |   3 +
 fs/nfs/internal.h                         |   9 +-
 fs/nfs/localio.c                          | 232 +++++++++++++++-----
 fs/nfs/nfs3proc.c                         |  46 +++-
 fs/nfs/nfs4state.c                        |   1 +
 fs/nfs/nfstrace.h                         |  32 ---
 fs/nfs/pagelist.c                         |   5 +-
 fs/nfs/write.c                            |   3 +-
 fs/nfs_common/Makefile                    |   3 +-
 fs/nfs_common/localio_trace.c             |  10 +
 fs/nfs_common/localio_trace.h             |  56 +++++
 fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
 fs/nfsd/filecache.c                       |  20 +-
 fs/nfsd/localio.c                         |   9 +-
 fs/nfsd/netns.h                           |  12 +-
 fs/nfsd/nfsctl.c                          |   6 +-
 fs/nfsd/nfssvc.c                          |  40 ++--
 include/linux/nfs_fs.h                    |  22 +-
 include/linux/nfs_fs_sb.h                 |   3 +-
 include/linux/nfs_xdr.h                   |   1 +
 include/linux/nfslocalio.h                |  48 +++--
 26 files changed, 674 insertions(+), 268 deletions(-)
 create mode 100644 fs/nfs_common/localio_trace.c
 create mode 100644 fs/nfs_common/localio_trace.h

-- 
2.44.0

[for-6.13 PATCH v3 01/14] nfs/localio: add direct IO enablement with sync and async IO support

[Mike Snitzer]

This commit simply adds the required O_DIRECT plumbing.  It doesn't
address the fact that NFS doesn't ensure all writes are page aligned
(nor device logical block size aligned as required by O_DIRECT).

Because NFS will read-modify-write for IO that isn't aligned, LOCALIO
will not use O_DIRECT semantics by default if/when an application
requests the use of O_DIRECT.  Allow the use of O_DIRECT semantics by:
1: Adding a flag to the nfs_pgio_header struct to allow the NFS
   O_DIRECT layer to signal that O_DIRECT was used by the application
2: Adding a 'localio_O_DIRECT_semantics' NFS module parameter that
   when enabled will cause LOCALIO to use O_DIRECT semantics (this may
   cause IO to fail if applications do not properly align their IO).

This commit is derived from code developed by Weston Andros Adamson.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 Documentation/filesystems/nfs/localio.rst | 11 +++
 fs/nfs/direct.c                           |  1 +
 fs/nfs/localio.c                          | 93 ++++++++++++++++++++---
 include/linux/nfs_xdr.h                   |  1 +
 4 files changed, 96 insertions(+), 10 deletions(-)

diff --git a/Documentation/filesystems/nfs/localio.rst b/Documentation/filesystems/nfs/localio.rst
index bd1967e2eab32..eb3dc764cfce8 100644
--- a/Documentation/filesystems/nfs/localio.rst
+++ b/Documentation/filesystems/nfs/localio.rst
@@ -306,6 +306,17 @@ is issuing IO to the underlying local filesystem that it is sharing with
 the NFS server. See: fs/nfs/localio.c:nfs_local_doio() and
 fs/nfs/localio.c:nfs_local_commit().
 
+With normal NFS that makes use of RPC to issue IO to the server, if an
+application uses O_DIRECT the NFS client will bypass the pagecache but
+the NFS server will not. Because the NFS server's use of buffered IO
+affords applications to be less precise with their alignment when
+issuing IO to the NFS client. LOCALIO can be configured to use O_DIRECT
+semantics by setting the 'localio_O_DIRECT_semantics' nfs module
+parameter to Y, e.g.:
+  echo Y > /sys/module/nfs/parameters/localio_O_DIRECT_semantics
+Once enabled, it will cause LOCALIO to use O_DIRECT semantics (this may
+cause IO to fail if applications do not properly align their IO).
+
 Security
 ========
 
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 90079ca134dd3..4b92493d6ff0e 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -303,6 +303,7 @@ static void nfs_read_sync_pgio_error(struct list_head *head, int error)
 static void nfs_direct_pgio_init(struct nfs_pgio_header *hdr)
 {
 	get_dreq(hdr->dreq);
+	set_bit(NFS_IOHDR_ODIRECT, &hdr->flags);
 }
 
 static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = {
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 4b8618cf114ca..7637786c5cb70 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -35,6 +35,7 @@ struct nfs_local_kiocb {
 	struct bio_vec		*bvec;
 	struct nfs_pgio_header	*hdr;
 	struct work_struct	work;
+	void (*aio_complete_work)(struct work_struct *);
 	struct nfsd_file	*localio;
 };
 
@@ -48,6 +49,11 @@ struct nfs_local_fsync_ctx {
 static bool localio_enabled __read_mostly = true;
 module_param(localio_enabled, bool, 0644);
 
+static bool localio_O_DIRECT_semantics __read_mostly = false;
+module_param(localio_O_DIRECT_semantics, bool, 0644);
+MODULE_PARM_DESC(localio_O_DIRECT_semantics,
+		 "LOCALIO will use O_DIRECT semantics to filesystem.");
+
 static inline bool nfs_client_is_local(const struct nfs_client *clp)
 {
 	return !!test_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
@@ -285,10 +291,19 @@ nfs_local_iocb_alloc(struct nfs_pgio_header *hdr,
 		kfree(iocb);
 		return NULL;
 	}
-	init_sync_kiocb(&iocb->kiocb, file);
+
+	if (localio_O_DIRECT_semantics &&
+	    test_bit(NFS_IOHDR_ODIRECT, &hdr->flags)) {
+		iocb->kiocb.ki_filp = file;
+		iocb->kiocb.ki_flags = IOCB_DIRECT;
+	} else
+		init_sync_kiocb(&iocb->kiocb, file);
+
 	iocb->kiocb.ki_pos = hdr->args.offset;
 	iocb->hdr = hdr;
 	iocb->kiocb.ki_flags &= ~IOCB_APPEND;
+	iocb->aio_complete_work = NULL;
+
 	return iocb;
 }
 
@@ -343,6 +358,18 @@ nfs_local_pgio_release(struct nfs_local_kiocb *iocb)
 	nfs_local_hdr_release(hdr, hdr->task.tk_ops);
 }
 
+/*
+ * Complete the I/O from iocb->kiocb.ki_complete()
+ *
+ * Note that this function can be called from a bottom half context,
+ * hence we need to queue the rpc_call_done() etc to a workqueue
+ */
+static inline void nfs_local_pgio_aio_complete(struct nfs_local_kiocb *iocb)
+{
+	INIT_WORK(&iocb->work, iocb->aio_complete_work);
+	queue_work(nfsiod_workqueue, &iocb->work);
+}
+
 static void
 nfs_local_read_done(struct nfs_local_kiocb *iocb, long status)
 {
@@ -365,6 +392,23 @@ nfs_local_read_done(struct nfs_local_kiocb *iocb, long status)
 			status > 0 ? status : 0, hdr->res.eof);
 }
 
+static void nfs_local_read_aio_complete_work(struct work_struct *work)
+{
+	struct nfs_local_kiocb *iocb =
+		container_of(work, struct nfs_local_kiocb, work);
+
+	nfs_local_pgio_release(iocb);
+}
+
+static void nfs_local_read_aio_complete(struct kiocb *kiocb, long ret)
+{
+	struct nfs_local_kiocb *iocb =
+		container_of(kiocb, struct nfs_local_kiocb, kiocb);
+
+	nfs_local_read_done(iocb, ret);
+	nfs_local_pgio_aio_complete(iocb); /* Calls nfs_local_read_aio_complete_work */
+}
+
 static void nfs_local_call_read(struct work_struct *work)
 {
 	struct nfs_local_kiocb *iocb =
@@ -379,10 +423,10 @@ static void nfs_local_call_read(struct work_struct *work)
 	nfs_local_iter_init(&iter, iocb, READ);
 
 	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);
+	if (status != -EIOCBQUEUED) {
+		nfs_local_read_done(iocb, status);
+		nfs_local_pgio_release(iocb);
+	}
 
 	revert_creds(save_cred);
 }
@@ -410,6 +454,11 @@ nfs_do_local_read(struct nfs_pgio_header *hdr,
 	nfs_local_pgio_init(hdr, call_ops);
 	hdr->res.eof = false;
 
+	if (iocb->kiocb.ki_flags & IOCB_DIRECT) {
+		iocb->kiocb.ki_complete = nfs_local_read_aio_complete;
+		iocb->aio_complete_work = nfs_local_read_aio_complete_work;
+	}
+
 	INIT_WORK(&iocb->work, nfs_local_call_read);
 	queue_work(nfslocaliod_workqueue, &iocb->work);
 
@@ -534,6 +583,24 @@ nfs_local_write_done(struct nfs_local_kiocb *iocb, long status)
 	nfs_local_pgio_done(hdr, status);
 }
 
+static void nfs_local_write_aio_complete_work(struct work_struct *work)
+{
+	struct nfs_local_kiocb *iocb =
+		container_of(work, struct nfs_local_kiocb, work);
+
+	nfs_local_vfs_getattr(iocb);
+	nfs_local_pgio_release(iocb);
+}
+
+static void nfs_local_write_aio_complete(struct kiocb *kiocb, long ret)
+{
+	struct nfs_local_kiocb *iocb =
+		container_of(kiocb, struct nfs_local_kiocb, kiocb);
+
+	nfs_local_write_done(iocb, ret);
+	nfs_local_pgio_aio_complete(iocb); /* Calls nfs_local_write_aio_complete_work */
+}
+
 static void nfs_local_call_write(struct work_struct *work)
 {
 	struct nfs_local_kiocb *iocb =
@@ -552,11 +619,11 @@ static void nfs_local_call_write(struct work_struct *work)
 	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);
+	if (status != -EIOCBQUEUED) {
+		nfs_local_write_done(iocb, status);
+		nfs_local_vfs_getattr(iocb);
+		nfs_local_pgio_release(iocb);
+	}
 
 	revert_creds(save_cred);
 	current->flags = old_flags;
@@ -592,10 +659,16 @@ nfs_do_local_write(struct nfs_pgio_header *hdr,
 	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);
 
+	if (iocb->kiocb.ki_flags & IOCB_DIRECT) {
+		iocb->kiocb.ki_complete = nfs_local_write_aio_complete;
+		iocb->aio_complete_work = nfs_local_write_aio_complete_work;
+	}
+
 	INIT_WORK(&iocb->work, nfs_local_call_write);
 	queue_work(nfslocaliod_workqueue, &iocb->work);
 
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index e74a87bb18a44..162b7c0c35557 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1632,6 +1632,7 @@ enum {
 	NFS_IOHDR_RESEND_PNFS,
 	NFS_IOHDR_RESEND_MDS,
 	NFS_IOHDR_UNSTABLE_WRITES,
+	NFS_IOHDR_ODIRECT,
 };
 
 struct nfs_io_completion;
-- 
2.44.0

[for-6.13 PATCH v3 02/14] nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations

[Mike Snitzer]

In later a commit LOCALIO must call both nfsd_file_get and
nfsd_file_put to manage extra nfsd_file references.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfsd/localio.c          | 2 ++
 include/linux/nfslocalio.h | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c
index f441cb9f74d56..8beda4c851119 100644
--- a/fs/nfsd/localio.c
+++ b/fs/nfsd/localio.c
@@ -29,6 +29,8 @@ static const struct nfsd_localio_operations nfsd_localio_ops = {
 	.nfsd_serv_put  = nfsd_serv_put,
 	.nfsd_open_local_fh = nfsd_open_local_fh,
 	.nfsd_file_put_local = nfsd_file_put_local,
+	.nfsd_file_get = nfsd_file_get,
+	.nfsd_file_put = nfsd_file_put,
 	.nfsd_file_file = nfsd_file_file,
 };
 
diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index 9202f4b24343d..ab6a2a53f505f 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -56,6 +56,8 @@ struct nfsd_localio_operations {
 						const struct nfs_fh *,
 						const fmode_t);
 	struct net *(*nfsd_file_put_local)(struct nfsd_file *);
+	struct nfsd_file *(*nfsd_file_get)(struct nfsd_file *);
+	void (*nfsd_file_put)(struct nfsd_file *);
 	struct file *(*nfsd_file_file)(struct nfsd_file *);
 } ____cacheline_aligned;
 
-- 
2.44.0

[for-6.13 PATCH v3 03/14] nfs_common: rename functions that invalidate LOCALIO nfs_clients

[Mike Snitzer]

Rename nfs_uuid_invalidate_one_client to nfs_localio_disable_client.
Rename nfs_uuid_invalidate_clients to nfs_localio_invalidate_clients.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
---
 fs/nfs/localio.c           | 2 +-
 fs/nfs_common/nfslocalio.c | 8 ++++----
 fs/nfsd/nfsctl.c           | 4 ++--
 include/linux/nfslocalio.h | 5 +++--
 4 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 7637786c5cb70..94af5d89bb996 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -140,7 +140,7 @@ void nfs_local_disable(struct nfs_client *clp)
 	spin_lock(&clp->cl_localio_lock);
 	if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
 		trace_nfs_local_disable(clp);
-		nfs_uuid_invalidate_one_client(&clp->cl_uuid);
+		nfs_localio_disable_client(&clp->cl_uuid);
 	}
 	spin_unlock(&clp->cl_localio_lock);
 }
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index a74ec08f6c96d..904439e4bb859 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -107,7 +107,7 @@ static void nfs_uuid_put_locked(nfs_uuid_t *nfs_uuid)
 	list_del_init(&nfs_uuid->list);
 }
 
-void nfs_uuid_invalidate_clients(struct list_head *list)
+void nfs_localio_invalidate_clients(struct list_head *list)
 {
 	nfs_uuid_t *nfs_uuid, *tmp;
 
@@ -116,9 +116,9 @@ void nfs_uuid_invalidate_clients(struct list_head *list)
 		nfs_uuid_put_locked(nfs_uuid);
 	spin_unlock(&nfs_uuid_lock);
 }
-EXPORT_SYMBOL_GPL(nfs_uuid_invalidate_clients);
+EXPORT_SYMBOL_GPL(nfs_localio_invalidate_clients);
 
-void nfs_uuid_invalidate_one_client(nfs_uuid_t *nfs_uuid)
+void nfs_localio_disable_client(nfs_uuid_t *nfs_uuid)
 {
 	if (nfs_uuid->net) {
 		spin_lock(&nfs_uuid_lock);
@@ -126,7 +126,7 @@ void nfs_uuid_invalidate_one_client(nfs_uuid_t *nfs_uuid)
 		spin_unlock(&nfs_uuid_lock);
 	}
 }
-EXPORT_SYMBOL_GPL(nfs_uuid_invalidate_one_client);
+EXPORT_SYMBOL_GPL(nfs_localio_disable_client);
 
 struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
 		   struct rpc_clnt *rpc_clnt, const struct cred *cred,
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 3adbc05ebaac4..727904d8a4d01 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -2276,14 +2276,14 @@ static __net_init int nfsd_net_init(struct net *net)
  * nfsd_net_pre_exit - Disconnect localio clients from net namespace
  * @net: a network namespace that is about to be destroyed
  *
- * This invalidated ->net pointers held by localio clients
+ * This invalidates ->net pointers held by localio clients
  * while they can still safely access nn->counter.
  */
 static __net_exit void nfsd_net_pre_exit(struct net *net)
 {
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
-	nfs_uuid_invalidate_clients(&nn->local_clients);
+	nfs_localio_invalidate_clients(&nn->local_clients);
 }
 #endif
 
diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index ab6a2a53f505f..a05d1043f2b07 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -37,8 +37,9 @@ bool nfs_uuid_begin(nfs_uuid_t *);
 void nfs_uuid_end(nfs_uuid_t *);
 void nfs_uuid_is_local(const uuid_t *, struct list_head *,
 		       struct net *, struct auth_domain *, struct module *);
-void nfs_uuid_invalidate_clients(struct list_head *list);
-void nfs_uuid_invalidate_one_client(nfs_uuid_t *nfs_uuid);
+
+void nfs_localio_disable_client(nfs_uuid_t *nfs_uuid);
+void nfs_localio_invalidate_clients(struct list_head *list);
 
 /* localio needs to map filehandle -> struct nfsd_file */
 extern struct nfsd_file *
-- 
2.44.0

[for-6.13 PATCH v3 04/14] nfs_common: move localio_lock to new lock member of nfs_uuid_t

[Mike Snitzer]

Remove cl_localio_lock from 'struct nfs_client' in favor of adding a
lock to the nfs_uuid_t struct (which is embedded in each nfs_client).

Push nfs_local_{enable,disable} implementation down to nfs_common.
Those methods now call nfs_localio_{enable,disable}_client.

This allows implementing nfs_localio_invalidate_clients in terms of
nfs_localio_disable_client.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfs/client.c            |  1 -
 fs/nfs/localio.c           | 14 +++-------
 fs/nfs_common/nfslocalio.c | 57 ++++++++++++++++++++++++++------------
 include/linux/nfs_fs_sb.h  |  1 -
 include/linux/nfslocalio.h |  8 +++++-
 5 files changed, 51 insertions(+), 30 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 550ca934c9cfc..e83e1ce046130 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -186,7 +186,6 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
 	seqlock_init(&clp->cl_boot_lock);
 	ktime_get_real_ts64(&clp->cl_nfssvc_boot);
 	nfs_uuid_init(&clp->cl_uuid);
-	spin_lock_init(&clp->cl_localio_lock);
 #endif /* CONFIG_NFS_LOCALIO */
 
 	clp->cl_principal = "*";
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 94af5d89bb996..7191135b47a42 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -126,10 +126,8 @@ const struct rpc_program nfslocalio_program = {
  */
 static void nfs_local_enable(struct nfs_client *clp)
 {
-	spin_lock(&clp->cl_localio_lock);
-	set_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
 	trace_nfs_local_enable(clp);
-	spin_unlock(&clp->cl_localio_lock);
+	nfs_localio_enable_client(clp);
 }
 
 /*
@@ -137,12 +135,8 @@ static void nfs_local_enable(struct nfs_client *clp)
  */
 void nfs_local_disable(struct nfs_client *clp)
 {
-	spin_lock(&clp->cl_localio_lock);
-	if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
-		trace_nfs_local_disable(clp);
-		nfs_localio_disable_client(&clp->cl_uuid);
-	}
-	spin_unlock(&clp->cl_localio_lock);
+	trace_nfs_local_disable(clp);
+	nfs_localio_disable_client(clp);
 }
 
 /*
@@ -184,7 +178,7 @@ static bool nfs_server_uuid_is_local(struct nfs_client *clp)
 	rpc_shutdown_client(rpcclient_localio);
 
 	/* Server is only local if it initialized required struct members */
-	if (status || !clp->cl_uuid.net || !clp->cl_uuid.dom)
+	if (status || !rcu_access_pointer(clp->cl_uuid.net) || !clp->cl_uuid.dom)
 		return false;
 
 	return true;
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index 904439e4bb859..abc132166742e 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -7,6 +7,9 @@
 #include <linux/module.h>
 #include <linux/list.h>
 #include <linux/nfslocalio.h>
+#include <linux/nfs3.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs_sb.h>
 #include <net/netns/generic.h>
 
 MODULE_LICENSE("GPL");
@@ -25,6 +28,7 @@ void nfs_uuid_init(nfs_uuid_t *nfs_uuid)
 	nfs_uuid->net = NULL;
 	nfs_uuid->dom = NULL;
 	INIT_LIST_HEAD(&nfs_uuid->list);
+	spin_lock_init(&nfs_uuid->lock);
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_init);
 
@@ -94,12 +98,23 @@ void nfs_uuid_is_local(const uuid_t *uuid, struct list_head *list,
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_is_local);
 
+void nfs_localio_enable_client(struct nfs_client *clp)
+{
+	nfs_uuid_t *nfs_uuid = &clp->cl_uuid;
+
+	spin_lock(&nfs_uuid->lock);
+	set_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
+	spin_unlock(&nfs_uuid->lock);
+}
+EXPORT_SYMBOL_GPL(nfs_localio_enable_client);
+
 static void nfs_uuid_put_locked(nfs_uuid_t *nfs_uuid)
 {
-	if (nfs_uuid->net) {
-		module_put(nfsd_mod);
-		nfs_uuid->net = NULL;
-	}
+	if (!nfs_uuid->net)
+		return;
+	module_put(nfsd_mod);
+	RCU_INIT_POINTER(nfs_uuid->net, NULL);
+
 	if (nfs_uuid->dom) {
 		auth_domain_put(nfs_uuid->dom);
 		nfs_uuid->dom = NULL;
@@ -107,27 +122,35 @@ static void nfs_uuid_put_locked(nfs_uuid_t *nfs_uuid)
 	list_del_init(&nfs_uuid->list);
 }
 
-void nfs_localio_invalidate_clients(struct list_head *list)
+void nfs_localio_disable_client(struct nfs_client *clp)
+{
+	nfs_uuid_t *nfs_uuid = &clp->cl_uuid;
+
+	spin_lock(&nfs_uuid->lock);
+	if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
+		spin_lock(&nfs_uuid_lock);
+		nfs_uuid_put_locked(nfs_uuid);
+		spin_unlock(&nfs_uuid_lock);
+	}
+	spin_unlock(&nfs_uuid->lock);
+}
+EXPORT_SYMBOL_GPL(nfs_localio_disable_client);
+
+void nfs_localio_invalidate_clients(struct list_head *cl_uuid_list)
 {
 	nfs_uuid_t *nfs_uuid, *tmp;
 
 	spin_lock(&nfs_uuid_lock);
-	list_for_each_entry_safe(nfs_uuid, tmp, list, list)
-		nfs_uuid_put_locked(nfs_uuid);
+	list_for_each_entry_safe(nfs_uuid, tmp, cl_uuid_list, list) {
+		struct nfs_client *clp =
+			container_of(nfs_uuid, struct nfs_client, cl_uuid);
+
+		nfs_localio_disable_client(clp);
+	}
 	spin_unlock(&nfs_uuid_lock);
 }
 EXPORT_SYMBOL_GPL(nfs_localio_invalidate_clients);
 
-void nfs_localio_disable_client(nfs_uuid_t *nfs_uuid)
-{
-	if (nfs_uuid->net) {
-		spin_lock(&nfs_uuid_lock);
-		nfs_uuid_put_locked(nfs_uuid);
-		spin_unlock(&nfs_uuid_lock);
-	}
-}
-EXPORT_SYMBOL_GPL(nfs_localio_disable_client);
-
 struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
 		   struct rpc_clnt *rpc_clnt, const struct cred *cred,
 		   const struct nfs_fh *nfs_fh, const fmode_t fmode)
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index b804346a97419..239d86ef166c0 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -132,7 +132,6 @@ struct nfs_client {
 	struct timespec64	cl_nfssvc_boot;
 	seqlock_t		cl_boot_lock;
 	nfs_uuid_t		cl_uuid;
-	spinlock_t		cl_localio_lock;
 #endif /* CONFIG_NFS_LOCALIO */
 };
 
diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index a05d1043f2b07..4d5583873f418 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -6,6 +6,7 @@
 #ifndef __LINUX_NFSLOCALIO_H
 #define __LINUX_NFSLOCALIO_H
 
+
 /* nfsd_file structure is purposely kept opaque to NFS client */
 struct nfsd_file;
 
@@ -19,6 +20,8 @@ struct nfsd_file;
 #include <linux/nfs.h>
 #include <net/net_namespace.h>
 
+struct nfs_client;
+
 /*
  * Useful to allow a client to negotiate if localio
  * possible with its server.
@@ -27,6 +30,8 @@ struct nfsd_file;
  */
 typedef struct {
 	uuid_t uuid;
+	/* sadly this struct is just over a cacheline, avoid bouncing */
+	spinlock_t ____cacheline_aligned lock;
 	struct list_head list;
 	struct net __rcu *net; /* nfsd's network namespace */
 	struct auth_domain *dom; /* auth_domain for localio */
@@ -38,7 +43,8 @@ void nfs_uuid_end(nfs_uuid_t *);
 void nfs_uuid_is_local(const uuid_t *, struct list_head *,
 		       struct net *, struct auth_domain *, struct module *);
 
-void nfs_localio_disable_client(nfs_uuid_t *nfs_uuid);
+void nfs_localio_enable_client(struct nfs_client *clp);
+void nfs_localio_disable_client(struct nfs_client *clp);
 void nfs_localio_invalidate_clients(struct list_head *list);
 
 /* localio needs to map filehandle -> struct nfsd_file */
-- 
2.44.0

[for-6.13 PATCH v3 05/14] nfs: cache all open LOCALIO nfsd_file(s) in client

[Mike Snitzer]

This commit switches from leaning heavily on NFSD's filecache (in
terms of GC'd nfsd_files) back to caching nfsd_files in the
client. A later commit will add the callback mechanism needed to
allow NFSD to force the NFS client to cleanup all cached nfsd_files.

Add nfs_fh_localio_init() and 'struct nfs_fh_localio' to cache opened
nfsd_file(s) (both a RO and RW nfsd_file is able to be opened and
cached for a given nfs_fh).

Update nfs_local_open_fh() to cache the nfsd_file once it is opened
using __nfs_local_open_fh().

Introduce nfs_close_local_fh() to clear the cached open nfsd_files and
call nfs_to_nfsd_file_put_local().

Refcounting is such that:
- nfs_local_open_fh() is paired with nfs_close_local_fh().
- __nfs_local_open_fh() is paired with nfs_to_nfsd_file_put_local().
- nfs_local_file_get() is paired with nfs_local_file_put().

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfs/flexfilelayout/flexfilelayout.c | 25 ++++----
 fs/nfs/flexfilelayout/flexfilelayout.h |  1 +
 fs/nfs/inode.c                         |  3 +
 fs/nfs/internal.h                      |  4 +-
 fs/nfs/localio.c                       | 89 +++++++++++++++++++++-----
 fs/nfs/pagelist.c                      |  5 +-
 fs/nfs/write.c                         |  3 +-
 fs/nfs_common/nfslocalio.c             | 52 ++++++++++++++-
 include/linux/nfs_fs.h                 | 22 ++++++-
 include/linux/nfslocalio.h             | 18 +++---
 10 files changed, 177 insertions(+), 45 deletions(-)

diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index f78115c6c2c12..ce61bf1ada6c3 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -164,18 +164,17 @@ decode_name(struct xdr_stream *xdr, u32 *id)
 }
 
 static struct nfsd_file *
-ff_local_open_fh(struct nfs_client *clp, const struct cred *cred,
+ff_local_open_fh(struct pnfs_layout_segment *lseg, u32 ds_idx,
+		 struct nfs_client *clp, const struct cred *cred,
 		 struct nfs_fh *fh, fmode_t mode)
 {
-	if (mode & FMODE_WRITE) {
-		/*
-		 * Always request read and write access since this corresponds
-		 * to a rw layout.
-		 */
-		mode |= FMODE_READ;
-	}
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
 
-	return nfs_local_open_fh(clp, cred, fh, mode);
+	return nfs_local_open_fh(clp, cred, fh, &mirror->nfl, mode);
+#else
+	return NULL;
+#endif
 }
 
 static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
@@ -247,6 +246,7 @@ static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
 		spin_lock_init(&mirror->lock);
 		refcount_set(&mirror->ref, 1);
 		INIT_LIST_HEAD(&mirror->mirrors);
+		nfs_localio_file_init(&mirror->nfl);
 	}
 	return mirror;
 }
@@ -257,6 +257,7 @@ static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
 
 	ff_layout_remove_mirror(mirror);
 	kfree(mirror->fh_versions);
+	nfs_close_local_fh(&mirror->nfl);
 	cred = rcu_access_pointer(mirror->ro_cred);
 	put_cred(cred);
 	cred = rcu_access_pointer(mirror->rw_cred);
@@ -1820,7 +1821,7 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
 	hdr->mds_offset = offset;
 
 	/* Start IO accounting for local read */
-	localio = ff_local_open_fh(ds->ds_clp, ds_cred, fh, FMODE_READ);
+	localio = ff_local_open_fh(lseg, idx, ds->ds_clp, ds_cred, fh, FMODE_READ);
 	if (localio) {
 		hdr->task.tk_start = ktime_get();
 		ff_layout_read_record_layoutstats_start(&hdr->task, hdr);
@@ -1896,7 +1897,7 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
 	hdr->args.offset = offset;
 
 	/* Start IO accounting for local write */
-	localio = ff_local_open_fh(ds->ds_clp, ds_cred, fh,
+	localio = ff_local_open_fh(lseg, idx, ds->ds_clp, ds_cred, fh,
 				   FMODE_READ|FMODE_WRITE);
 	if (localio) {
 		hdr->task.tk_start = ktime_get();
@@ -1981,7 +1982,7 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
 		data->args.fh = fh;
 
 	/* Start IO accounting for local commit */
-	localio = ff_local_open_fh(ds->ds_clp, ds_cred, fh,
+	localio = ff_local_open_fh(lseg, idx, ds->ds_clp, ds_cred, fh,
 				   FMODE_READ|FMODE_WRITE);
 	if (localio) {
 		data->task.tk_start = ktime_get();
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.h b/fs/nfs/flexfilelayout/flexfilelayout.h
index f84b3fb0dddd8..095df09017a57 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.h
+++ b/fs/nfs/flexfilelayout/flexfilelayout.h
@@ -83,6 +83,7 @@ struct nfs4_ff_layout_mirror {
 	nfs4_stateid			stateid;
 	const struct cred __rcu		*ro_cred;
 	const struct cred __rcu		*rw_cred;
+	struct nfs_file_localio		nfl;
 	refcount_t			ref;
 	spinlock_t			lock;
 	unsigned long			flags;
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 596f351701372..1aa67fca69b2f 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1137,6 +1137,8 @@ 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;
+	nfs_localio_file_init(&ctx->nfl);
+
 	return ctx;
 }
 EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
@@ -1168,6 +1170,7 @@ 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);
+	nfs_close_local_fh(&ctx->nfl);
 	kfree_rcu(ctx, rcu_head);
 }
 
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 430733e3eff26..57af3ab3adbe5 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -459,6 +459,7 @@ extern void nfs_local_probe(struct nfs_client *);
 extern struct nfsd_file *nfs_local_open_fh(struct nfs_client *,
 					   const struct cred *,
 					   struct nfs_fh *,
+					   struct nfs_file_localio *,
 					   const fmode_t);
 extern int nfs_local_doio(struct nfs_client *,
 			  struct nfsd_file *,
@@ -474,7 +475,8 @@ static inline void nfs_local_disable(struct nfs_client *clp) {}
 static inline void nfs_local_probe(struct nfs_client *clp) {}
 static inline struct nfsd_file *
 nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
-		  struct nfs_fh *fh, const fmode_t mode)
+		  struct nfs_fh *fh, struct nfs_file_localio *nfl,
+		  const fmode_t mode)
 {
 	return NULL;
 }
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 7191135b47a42..7e432057c3a1f 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -211,27 +211,33 @@ void nfs_local_probe(struct nfs_client *clp)
 }
 EXPORT_SYMBOL_GPL(nfs_local_probe);
 
+static inline struct nfsd_file *nfs_local_file_get(struct nfsd_file *nf)
+{
+	return nfs_to->nfsd_file_get(nf);
+}
+
+static inline void nfs_local_file_put(struct nfsd_file *nf)
+{
+	nfs_to->nfsd_file_put(nf);
+}
+
 /*
- * nfs_local_open_fh - open a local filehandle in terms of nfsd_file
+ * __nfs_local_open_fh - open a local filehandle in terms of nfsd_file.
  *
- * Returns a pointer to a struct nfsd_file or NULL
+ * Returns a pointer to a struct nfsd_file or ERR_PTR.
+ * Caller must release returned nfsd_file with nfs_to_nfsd_file_put_local().
  */
-struct nfsd_file *
-nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
-		  struct nfs_fh *fh, const fmode_t mode)
+static struct nfsd_file *
+__nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
+		    struct nfs_fh *fh, struct nfs_file_localio *nfl,
+		    const fmode_t mode)
 {
 	struct nfsd_file *localio;
-	int status;
-
-	if (!nfs_server_is_local(clp))
-		return NULL;
-	if (mode & ~(FMODE_READ | FMODE_WRITE))
-		return NULL;
 
 	localio = nfs_open_local_fh(&clp->cl_uuid, clp->cl_rpcclient,
-				    cred, fh, mode);
+				    cred, fh, nfl, mode);
 	if (IS_ERR(localio)) {
-		status = PTR_ERR(localio);
+		int status = PTR_ERR(localio);
 		trace_nfs_local_open_fh(fh, mode, status);
 		switch (status) {
 		case -ENOMEM:
@@ -240,10 +246,59 @@ nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
 			/* Revalidate localio, will disable if unsupported */
 			nfs_local_probe(clp);
 		}
-		return NULL;
 	}
 	return localio;
 }
+
+/*
+ * nfs_local_open_fh - open a local filehandle in terms of nfsd_file.
+ * First checking if the open nfsd_file is already cached, otherwise
+ * must __nfs_local_open_fh and insert the nfsd_file in nfs_file_localio.
+ *
+ * Returns a pointer to a struct nfsd_file or NULL.
+ */
+struct nfsd_file *
+nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
+		  struct nfs_fh *fh, struct nfs_file_localio *nfl,
+		  const fmode_t mode)
+{
+	struct nfsd_file *nf, *new, __rcu **pnf;
+
+	if (!nfs_server_is_local(clp))
+		return NULL;
+	if (mode & ~(FMODE_READ | FMODE_WRITE))
+		return NULL;
+
+	if (mode & FMODE_WRITE)
+		pnf = &nfl->rw_file;
+	else
+		pnf = &nfl->ro_file;
+
+	new = NULL;
+	rcu_read_lock();
+	nf = rcu_dereference(*pnf);
+	if (!nf) {
+		rcu_read_unlock();
+		new = __nfs_local_open_fh(clp, cred, fh, nfl, mode);
+		if (IS_ERR(new))
+			return NULL;
+		/* try to swap in the pointer */
+		spin_lock(&clp->cl_uuid.lock);
+		nf = rcu_dereference_protected(*pnf, 1);
+		if (!nf) {
+			nf = new;
+			new = NULL;
+			rcu_assign_pointer(*pnf, nf);
+		}
+		spin_unlock(&clp->cl_uuid.lock);
+		rcu_read_lock();
+	}
+	nf = nfs_local_file_get(nf);
+	rcu_read_unlock();
+	if (new)
+		nfs_to_nfsd_file_put_local(new);
+	return nf;
+}
 EXPORT_SYMBOL_GPL(nfs_local_open_fh);
 
 static struct bio_vec *
@@ -347,7 +402,7 @@ nfs_local_pgio_release(struct nfs_local_kiocb *iocb)
 {
 	struct nfs_pgio_header *hdr = iocb->hdr;
 
-	nfs_to_nfsd_file_put_local(iocb->localio);
+	nfs_local_file_put(iocb->localio);
 	nfs_local_iocb_free(iocb);
 	nfs_local_hdr_release(hdr, hdr->task.tk_ops);
 }
@@ -694,7 +749,7 @@ int nfs_local_doio(struct nfs_client *clp, struct nfsd_file *localio,
 	if (status != 0) {
 		if (status == -EAGAIN)
 			nfs_local_disable(clp);
-		nfs_to_nfsd_file_put_local(localio);
+		nfs_local_file_put(localio);
 		hdr->task.tk_status = status;
 		nfs_local_hdr_release(hdr, call_ops);
 	}
@@ -745,7 +800,7 @@ nfs_local_release_commit_data(struct nfsd_file *localio,
 		struct nfs_commit_data *data,
 		const struct rpc_call_ops *call_ops)
 {
-	nfs_to_nfsd_file_put_local(localio);
+	nfs_local_file_put(localio);
 	call_ops->rpc_call_done(&data->task, data);
 	call_ops->rpc_release(data);
 }
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index e27c07bd89290..11968dcb72431 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -961,8 +961,9 @@ static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
 		struct nfs_client *clp = NFS_SERVER(hdr->inode)->nfs_client;
 
 		struct nfsd_file *localio =
-			nfs_local_open_fh(clp, hdr->cred,
-					  hdr->args.fh, hdr->args.context->mode);
+			nfs_local_open_fh(clp, hdr->cred, hdr->args.fh,
+					  &hdr->args.context->nfl,
+					  hdr->args.context->mode);
 
 		if (NFS_SERVER(hdr->inode)->nfs_client->cl_minorversion)
 			task_flags = RPC_TASK_MOVEABLE;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 2da00987d9ed4..75779e3cac16d 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1817,7 +1817,8 @@ nfs_commit_list(struct inode *inode, struct list_head *head, int how,
 		task_flags = RPC_TASK_MOVEABLE;
 
 	localio = nfs_local_open_fh(NFS_SERVER(inode)->nfs_client, data->cred,
-				    data->args.fh, data->context->mode);
+				    data->args.fh, &data->context->nfl,
+				    data->context->mode);
 	return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode),
 				   data->mds_ops, how,
 				   RPC_TASK_CRED_NOREF | task_flags, localio);
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index abc132166742e..35a2e48731df6 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -9,7 +9,7 @@
 #include <linux/nfslocalio.h>
 #include <linux/nfs3.h>
 #include <linux/nfs4.h>
-#include <linux/nfs_fs_sb.h>
+#include <linux/nfs_fs.h>
 #include <net/netns/generic.h>
 
 MODULE_LICENSE("GPL");
@@ -151,9 +151,18 @@ void nfs_localio_invalidate_clients(struct list_head *cl_uuid_list)
 }
 EXPORT_SYMBOL_GPL(nfs_localio_invalidate_clients);
 
+static void nfs_uuid_add_file(nfs_uuid_t *nfs_uuid, struct nfs_file_localio *nfl)
+{
+	spin_lock(&nfs_uuid_lock);
+	if (!nfl->nfs_uuid)
+		rcu_assign_pointer(nfl->nfs_uuid, nfs_uuid);
+	spin_unlock(&nfs_uuid_lock);
+}
+
 struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
 		   struct rpc_clnt *rpc_clnt, const struct cred *cred,
-		   const struct nfs_fh *nfs_fh, const fmode_t fmode)
+		   const struct nfs_fh *nfs_fh, struct nfs_file_localio *nfl,
+		   const fmode_t fmode)
 {
 	struct net *net;
 	struct nfsd_file *localio;
@@ -180,11 +189,50 @@ struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
 					     cred, nfs_fh, fmode);
 	if (IS_ERR(localio))
 		nfs_to_nfsd_net_put(net);
+	else
+		nfs_uuid_add_file(uuid, nfl);
 
 	return localio;
 }
 EXPORT_SYMBOL_GPL(nfs_open_local_fh);
 
+void nfs_close_local_fh(struct nfs_file_localio *nfl)
+{
+	struct nfsd_file *ro_nf = NULL;
+	struct nfsd_file *rw_nf = NULL;
+	nfs_uuid_t *nfs_uuid;
+
+	rcu_read_lock();
+	nfs_uuid = rcu_dereference(nfl->nfs_uuid);
+	if (!nfs_uuid) {
+		/* regular (non-LOCALIO) NFS will hammer this */
+		rcu_read_unlock();
+		return;
+	}
+
+	ro_nf = rcu_access_pointer(nfl->ro_file);
+	rw_nf = rcu_access_pointer(nfl->rw_file);
+	if (ro_nf || rw_nf) {
+		spin_lock(&nfs_uuid_lock);
+		if (ro_nf)
+			ro_nf = rcu_dereference_protected(xchg(&nfl->ro_file, NULL), 1);
+		if (rw_nf)
+			rw_nf = rcu_dereference_protected(xchg(&nfl->rw_file, NULL), 1);
+
+		rcu_assign_pointer(nfl->nfs_uuid, NULL);
+		spin_unlock(&nfs_uuid_lock);
+		rcu_read_unlock();
+
+		if (ro_nf)
+			nfs_to_nfsd_file_put_local(ro_nf);
+		if (rw_nf)
+			nfs_to_nfsd_file_put_local(rw_nf);
+		return;
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(nfs_close_local_fh);
+
 /*
  * The NFS LOCALIO code needs to call into NFSD using various symbols,
  * but cannot be statically linked, because that will make the NFS
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 039898d70954f..67ae2c3f41d20 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -77,6 +77,23 @@ struct nfs_lock_context {
 	struct rcu_head	rcu_head;
 };
 
+struct nfs_file_localio {
+	struct nfsd_file __rcu *ro_file;
+	struct nfsd_file __rcu *rw_file;
+	struct list_head list;
+	void __rcu *nfs_uuid; /* opaque pointer to 'nfs_uuid_t' */
+};
+
+static inline void nfs_localio_file_init(struct nfs_file_localio *nfl)
+{
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	nfl->ro_file = NULL;
+	nfl->rw_file = NULL;
+	INIT_LIST_HEAD(&nfl->list);
+	nfl->nfs_uuid = NULL;
+#endif
+}
+
 struct nfs4_state;
 struct nfs_open_context {
 	struct nfs_lock_context lock_context;
@@ -87,15 +104,16 @@ struct nfs_open_context {
 	struct nfs4_state *state;
 	fmode_t mode;
 
+	int error;
 	unsigned long flags;
 #define NFS_CONTEXT_BAD			(2)
 #define NFS_CONTEXT_UNLOCK	(3)
 #define NFS_CONTEXT_FILE_OPEN		(4)
-	int error;
 
-	struct list_head list;
 	struct nfs4_threshold	*mdsthreshold;
+	struct list_head list;
 	struct rcu_head	rcu_head;
+	struct nfs_file_localio nfl;
 };
 
 struct nfs_open_dir_context {
diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index 4d5583873f418..7cfc6720ed26d 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -6,10 +6,6 @@
 #ifndef __LINUX_NFSLOCALIO_H
 #define __LINUX_NFSLOCALIO_H
 
-
-/* nfsd_file structure is purposely kept opaque to NFS client */
-struct nfsd_file;
-
 #if IS_ENABLED(CONFIG_NFS_LOCALIO)
 
 #include <linux/module.h>
@@ -21,6 +17,7 @@ struct nfsd_file;
 #include <net/net_namespace.h>
 
 struct nfs_client;
+struct nfs_file_localio;
 
 /*
  * Useful to allow a client to negotiate if localio
@@ -52,6 +49,7 @@ extern struct nfsd_file *
 nfsd_open_local_fh(struct net *, struct auth_domain *, struct rpc_clnt *,
 		   const struct cred *, const struct nfs_fh *,
 		   const fmode_t) __must_hold(rcu);
+void nfs_close_local_fh(struct nfs_file_localio *);
 
 struct nfsd_localio_operations {
 	bool (*nfsd_serv_try_get)(struct net *);
@@ -73,7 +71,8 @@ extern const struct nfsd_localio_operations *nfs_to;
 
 struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *,
 		   struct rpc_clnt *, const struct cred *,
-		   const struct nfs_fh *, const fmode_t);
+		   const struct nfs_fh *, struct nfs_file_localio *,
+		   const fmode_t);
 
 static inline void nfs_to_nfsd_net_put(struct net *net)
 {
@@ -100,12 +99,15 @@ static inline void nfs_to_nfsd_file_put_local(struct nfsd_file *localio)
 }
 
 #else   /* CONFIG_NFS_LOCALIO */
+
+struct nfs_file_localio;
+static inline void nfs_close_local_fh(struct nfs_file_localio *nfl)
+{
+}
 static inline void nfsd_localio_ops_init(void)
 {
 }
-static inline void nfs_to_nfsd_file_put_local(struct nfsd_file *localio)
-{
-}
+
 #endif  /* CONFIG_NFS_LOCALIO */
 
 #endif  /* __LINUX_NFSLOCALIO_H */
-- 
2.44.0

[for-6.13 PATCH v3 06/14] nfsd: update percpu_ref to manage references on nfsd_net

[Mike Snitzer]

Holding a reference on nfsd_net is what is required, it was never
actually about ensuring nn->nfsd_serv available.

Move waiting for outstanding percpu references from
nfsd_destroy_serv() to nfsd_shutdown_net().

By moving it later it will be possible to invalidate localio clients
during nfsd_file_cache_shutdown_net() via __nfsd_file_cache_purge().

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfsd/nfssvc.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 49e2f32102ab5..6ca5540424266 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -436,6 +436,10 @@ static void nfsd_shutdown_net(struct net *net)
 
 	if (!nn->nfsd_net_up)
 		return;
+
+	percpu_ref_kill_and_confirm(&nn->nfsd_serv_ref, nfsd_serv_done);
+	wait_for_completion(&nn->nfsd_serv_confirm_done);
+
 	nfsd_export_flush(net);
 	nfs4_state_shutdown_net(net);
 	nfsd_reply_cache_shutdown(nn);
@@ -444,7 +448,10 @@ static void nfsd_shutdown_net(struct net *net)
 		lockd_down(net);
 		nn->lockd_up = false;
 	}
+
+	wait_for_completion(&nn->nfsd_serv_free_done);
 	percpu_ref_exit(&nn->nfsd_serv_ref);
+
 	nn->nfsd_net_up = false;
 	nfsd_shutdown_generic();
 }
@@ -526,11 +533,6 @@ void nfsd_destroy_serv(struct net *net)
 
 	lockdep_assert_held(&nfsd_mutex);
 
-	percpu_ref_kill_and_confirm(&nn->nfsd_serv_ref, nfsd_serv_done);
-	wait_for_completion(&nn->nfsd_serv_confirm_done);
-	wait_for_completion(&nn->nfsd_serv_free_done);
-	/* percpu_ref_exit is called in nfsd_shutdown_net */
-
 	spin_lock(&nfsd_notifier_lock);
 	nn->nfsd_serv = NULL;
 	spin_unlock(&nfsd_notifier_lock);
-- 
2.44.0

[for-6.13 PATCH v3 07/14] nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_

[Mike Snitzer]

Also update Documentation/filesystems/nfs/localio.rst accordingly
and reduce the technical documentation debt that was previously
captured in that document.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 Documentation/filesystems/nfs/localio.rst | 81 +++++++----------------
 fs/nfs_common/nfslocalio.c                | 10 ++-
 fs/nfsd/filecache.c                       |  2 +-
 fs/nfsd/localio.c                         |  4 +-
 fs/nfsd/netns.h                           | 11 +--
 fs/nfsd/nfssvc.c                          | 34 +++++-----
 include/linux/nfslocalio.h                | 12 ++--
 7 files changed, 64 insertions(+), 90 deletions(-)

diff --git a/Documentation/filesystems/nfs/localio.rst b/Documentation/filesystems/nfs/localio.rst
index eb3dc764cfce8..9d991a958c81c 100644
--- a/Documentation/filesystems/nfs/localio.rst
+++ b/Documentation/filesystems/nfs/localio.rst
@@ -218,64 +218,30 @@ NFS Client and Server Interlock
 ===============================
 
 LOCALIO provides the nfs_uuid_t object and associated interfaces to
-allow proper network namespace (net-ns) and NFSD object refcounting:
+allow proper network namespace (net-ns) and NFSD object refcounting.
 
-    We don't want to keep a long-term counted reference on each NFSD's
-    net-ns in the client because that prevents a server container from
-    completely shutting down.
-
-    So we avoid taking a reference at all and rely on the per-cpu
-    reference to the server (detailed below) being sufficient to keep
-    the net-ns active. This involves allowing the NFSD's net-ns exit
-    code to iterate all active clients and clear their ->net pointers
-    (which are needed to find the per-cpu-refcount for the nfsd_serv).
-
-    Details:
-
-     - Embed nfs_uuid_t in nfs_client. nfs_uuid_t provides a list_head
-       that can be used to find the client. It does add the 16-byte
-       uuid_t to nfs_client so it is bigger than needed (given that
-       uuid_t is only used during the initial NFS client and server
-       LOCALIO handshake to determine if they are local to each other).
-       If that is really a problem we can find a fix.
-
-     - When the nfs server confirms that the uuid_t is local, it moves
-       the nfs_uuid_t onto a per-net-ns list in NFSD's nfsd_net.
-
-     - When each server's net-ns is shutting down - in a "pre_exit"
-       handler, all these nfs_uuid_t have their ->net cleared. There is
-       an rcu_synchronize() call between pre_exit() handlers and exit()
-       handlers so any caller that sees nfs_uuid_t ->net as not NULL can
-       safely manage the per-cpu-refcount for nfsd_serv.
-
-     - The client's nfs_uuid_t is passed to nfsd_open_local_fh() so it
-       can safely dereference ->net in a private rcu_read_lock() section
-       to allow safe access to the associated nfsd_net and nfsd_serv.
-
-So LOCALIO required the introduction and use of NFSD's percpu_ref to
-interlock nfsd_destroy_serv() and nfsd_open_local_fh(), to ensure each
-nn->nfsd_serv is not destroyed while in use by nfsd_open_local_fh(), and
+LOCALIO required the introduction and use of NFSD's percpu nfsd_net_ref
+to interlock nfsd_shutdown_net() and nfsd_open_local_fh(), to ensure
+each net-ns is not destroyed while in use by nfsd_open_local_fh(), and
 warrants a more detailed explanation:
 
-    nfsd_open_local_fh() uses nfsd_serv_try_get() before opening its
+    nfsd_open_local_fh() uses nfsd_net_try_get() before opening its
     nfsd_file handle and then the caller (NFS client) must drop the
-    reference for the nfsd_file and associated nn->nfsd_serv using
-    nfs_file_put_local() once it has completed its IO.
+    reference for the nfsd_file and associated net-ns using
+    nfsd_file_put_local() once it has completed its IO.
 
     This interlock working relies heavily on nfsd_open_local_fh() being
     afforded the ability to safely deal with the possibility that the
     NFSD's net-ns (and nfsd_net by association) may have been destroyed
-    by nfsd_destroy_serv() via nfsd_shutdown_net() -- which is only
-    possible given the nfs_uuid_t ->net pointer managemenet detailed
-    above.
+    by nfsd_destroy_serv() via nfsd_shutdown_net().
 
-All told, this elaborate interlock of the NFS client and server has been
-verified to fix an easy to hit crash that would occur if an NFSD
-instance running in a container, with a LOCALIO client mounted, is
-shutdown. Upon restart of the container and associated NFSD the client
-would go on to crash due to NULL pointer dereference that occurred due
-to the LOCALIO client's attempting to nfsd_open_local_fh(), using
-nn->nfsd_serv, without having a proper reference on nn->nfsd_serv.
+This interlock of the NFS client and server has been verified to fix an
+easy to hit crash that would occur if an NFSD instance running in a
+container, with a LOCALIO client mounted, is shutdown. Upon restart of
+the container and associated NFSD, the client would go on to crash due
+to NULL pointer dereference that occurred due to the LOCALIO client's
+attempting to nfsd_open_local_fh() without having a proper reference on
+NFSD's net-ns.
 
 NFS Client issues IO instead of Server
 ======================================
@@ -308,14 +274,17 @@ fs/nfs/localio.c:nfs_local_commit().
 
 With normal NFS that makes use of RPC to issue IO to the server, if an
 application uses O_DIRECT the NFS client will bypass the pagecache but
-the NFS server will not. Because the NFS server's use of buffered IO
-affords applications to be less precise with their alignment when
-issuing IO to the NFS client. LOCALIO can be configured to use O_DIRECT
-semantics by setting the 'localio_O_DIRECT_semantics' nfs module
+the NFS server will not. The NFS server's use of buffered IO affords
+applications to be less precise with their alignment when issuing IO to
+the NFS client. But if all applications properly align their IO, LOCALIO
+can be configured to use end-to-end O_DIRECT semantics from the NFS
+client to the underlying local filesystem, that it is sharing with
+the NFS server, by setting the 'localio_O_DIRECT_semantics' nfs module
 parameter to Y, e.g.:
-  echo Y > /sys/module/nfs/parameters/localio_O_DIRECT_semantics
-Once enabled, it will cause LOCALIO to use O_DIRECT semantics (this may
-cause IO to fail if applications do not properly align their IO).
+    echo Y > /sys/module/nfs/parameters/localio_O_DIRECT_semantics
+Once enabled, it will cause LOCALIO to use end-to-end O_DIRECT semantics
+(but again, this may cause IO to fail if applications do not properly
+align their IO).
 
 Security
 ========
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index 35a2e48731df6..e75cd21f4c8bc 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -159,6 +159,10 @@ static void nfs_uuid_add_file(nfs_uuid_t *nfs_uuid, struct nfs_file_localio *nfl
 	spin_unlock(&nfs_uuid_lock);
 }
 
+/*
+ * Caller is responsible for calling nfsd_net_put and
+ * nfsd_file_put (via nfs_to_nfsd_file_put_local).
+ */
 struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
 		   struct rpc_clnt *rpc_clnt, const struct cred *cred,
 		   const struct nfs_fh *nfs_fh, struct nfs_file_localio *nfl,
@@ -171,7 +175,7 @@ struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
 	 * Not running in nfsd context, so must safely get reference on nfsd_serv.
 	 * But the server may already be shutting down, if so disallow new localio.
 	 * uuid->net is NOT a counted reference, but rcu_read_lock() ensures that
-	 * if uuid->net is not NULL, then calling nfsd_serv_try_get() is safe
+	 * if uuid->net is not NULL, then calling nfsd_net_try_get() is safe
 	 * and if it succeeds we will have an implied reference to the net.
 	 *
 	 * Otherwise NFS may not have ref on NFSD and therefore cannot safely
@@ -179,12 +183,12 @@ struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
 	 */
 	rcu_read_lock();
 	net = rcu_dereference(uuid->net);
-	if (!net || !nfs_to->nfsd_serv_try_get(net)) {
+	if (!net || !nfs_to->nfsd_net_try_get(net)) {
 		rcu_read_unlock();
 		return ERR_PTR(-ENXIO);
 	}
 	rcu_read_unlock();
-	/* We have an implied reference to net thanks to nfsd_serv_try_get */
+	/* We have an implied reference to net thanks to nfsd_net_try_get */
 	localio = nfs_to->nfsd_open_local_fh(net, uuid->dom, rpc_clnt,
 					     cred, nfs_fh, fmode);
 	if (IS_ERR(localio))
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 9a62b4da89bb7..fac98b2cb463a 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -391,7 +391,7 @@ nfsd_file_put(struct nfsd_file *nf)
 }
 
 /**
- * nfsd_file_put_local - put nfsd_file reference and arm nfsd_serv_put in caller
+ * nfsd_file_put_local - put nfsd_file reference and arm nfsd_net_put in caller
  * @nf: nfsd_file of which to put the reference
  *
  * First save the associated net to return to caller, then put
diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c
index 8beda4c851119..f9a91cd3b5ec7 100644
--- a/fs/nfsd/localio.c
+++ b/fs/nfsd/localio.c
@@ -25,8 +25,8 @@
 #include "cache.h"
 
 static const struct nfsd_localio_operations nfsd_localio_ops = {
-	.nfsd_serv_try_get  = nfsd_serv_try_get,
-	.nfsd_serv_put  = nfsd_serv_put,
+	.nfsd_net_try_get  = nfsd_net_try_get,
+	.nfsd_net_put  = nfsd_net_put,
 	.nfsd_open_local_fh = nfsd_open_local_fh,
 	.nfsd_file_put_local = nfsd_file_put_local,
 	.nfsd_file_get = nfsd_file_get,
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 26f7b34d1a030..8faef59d71229 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -140,9 +140,10 @@ struct nfsd_net {
 
 	struct svc_info nfsd_info;
 #define nfsd_serv nfsd_info.serv
-	struct percpu_ref nfsd_serv_ref;
-	struct completion nfsd_serv_confirm_done;
-	struct completion nfsd_serv_free_done;
+
+	struct percpu_ref nfsd_net_ref;
+	struct completion nfsd_net_confirm_done;
+	struct completion nfsd_net_free_done;
 
 	/*
 	 * clientid and stateid data for construction of net unique COPY
@@ -229,8 +230,8 @@ struct nfsd_net {
 extern bool nfsd_support_version(int vers);
 extern unsigned int nfsd_net_id;
 
-bool nfsd_serv_try_get(struct net *net);
-void nfsd_serv_put(struct net *net);
+bool nfsd_net_try_get(struct net *net);
+void nfsd_net_put(struct net *net);
 
 void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn);
 void nfsd_reset_write_verifier(struct nfsd_net *nn);
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 6ca5540424266..e937e2d0ce62c 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -214,32 +214,32 @@ int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change
 	return 0;
 }
 
-bool nfsd_serv_try_get(struct net *net) __must_hold(rcu)
+bool nfsd_net_try_get(struct net *net) __must_hold(rcu)
 {
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
-	return (nn && percpu_ref_tryget_live(&nn->nfsd_serv_ref));
+	return (nn && percpu_ref_tryget_live(&nn->nfsd_net_ref));
 }
 
-void nfsd_serv_put(struct net *net) __must_hold(rcu)
+void nfsd_net_put(struct net *net) __must_hold(rcu)
 {
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
-	percpu_ref_put(&nn->nfsd_serv_ref);
+	percpu_ref_put(&nn->nfsd_net_ref);
 }
 
-static void nfsd_serv_done(struct percpu_ref *ref)
+static void nfsd_net_done(struct percpu_ref *ref)
 {
-	struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_serv_ref);
+	struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_net_ref);
 
-	complete(&nn->nfsd_serv_confirm_done);
+	complete(&nn->nfsd_net_confirm_done);
 }
 
-static void nfsd_serv_free(struct percpu_ref *ref)
+static void nfsd_net_free(struct percpu_ref *ref)
 {
-	struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_serv_ref);
+	struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_net_ref);
 
-	complete(&nn->nfsd_serv_free_done);
+	complete(&nn->nfsd_net_free_done);
 }
 
 /*
@@ -437,8 +437,8 @@ static void nfsd_shutdown_net(struct net *net)
 	if (!nn->nfsd_net_up)
 		return;
 
-	percpu_ref_kill_and_confirm(&nn->nfsd_serv_ref, nfsd_serv_done);
-	wait_for_completion(&nn->nfsd_serv_confirm_done);
+	percpu_ref_kill_and_confirm(&nn->nfsd_net_ref, nfsd_net_done);
+	wait_for_completion(&nn->nfsd_net_confirm_done);
 
 	nfsd_export_flush(net);
 	nfs4_state_shutdown_net(net);
@@ -449,8 +449,8 @@ static void nfsd_shutdown_net(struct net *net)
 		nn->lockd_up = false;
 	}
 
-	wait_for_completion(&nn->nfsd_serv_free_done);
-	percpu_ref_exit(&nn->nfsd_serv_ref);
+	wait_for_completion(&nn->nfsd_net_free_done);
+	percpu_ref_exit(&nn->nfsd_net_ref);
 
 	nn->nfsd_net_up = false;
 	nfsd_shutdown_generic();
@@ -654,12 +654,12 @@ int nfsd_create_serv(struct net *net)
 	if (nn->nfsd_serv)
 		return 0;
 
-	error = percpu_ref_init(&nn->nfsd_serv_ref, nfsd_serv_free,
+	error = percpu_ref_init(&nn->nfsd_net_ref, nfsd_net_free,
 				0, GFP_KERNEL);
 	if (error)
 		return error;
-	init_completion(&nn->nfsd_serv_free_done);
-	init_completion(&nn->nfsd_serv_confirm_done);
+	init_completion(&nn->nfsd_net_free_done);
+	init_completion(&nn->nfsd_net_confirm_done);
 
 	if (nfsd_max_blksize == 0)
 		nfsd_max_blksize = nfsd_get_default_max_blksize();
diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index 7cfc6720ed26d..aa2b5c6561ab0 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -52,8 +52,8 @@ nfsd_open_local_fh(struct net *, struct auth_domain *, struct rpc_clnt *,
 void nfs_close_local_fh(struct nfs_file_localio *);
 
 struct nfsd_localio_operations {
-	bool (*nfsd_serv_try_get)(struct net *);
-	void (*nfsd_serv_put)(struct net *);
+	bool (*nfsd_net_try_get)(struct net *);
+	void (*nfsd_net_put)(struct net *);
 	struct nfsd_file *(*nfsd_open_local_fh)(struct net *,
 						struct auth_domain *,
 						struct rpc_clnt *,
@@ -77,12 +77,12 @@ struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *,
 static inline void nfs_to_nfsd_net_put(struct net *net)
 {
 	/*
-	 * Once reference to nfsd_serv is dropped, NFSD could be
-	 * unloaded, so ensure safe return from nfsd_file_put_local()
-	 * by always taking RCU.
+	 * Once reference to net (and associated nfsd_serv) is dropped, NFSD
+	 * could be unloaded, so ensure safe return from nfsd_net_put() by
+	 * always taking RCU.
 	 */
 	rcu_read_lock();
-	nfs_to->nfsd_serv_put(net);
+	nfs_to->nfsd_net_put(net);
 	rcu_read_unlock();
 }
 
-- 
2.44.0

[for-6.13 PATCH v3 08/14] nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file

[Mike Snitzer]

Now that LOCALIO no longer leans on NFSD's filecache for caching open
files (and instead uses NFS client-side open nfsd_file caching) there
is no need to use NFSD filecache's GC feature.  Avoiding GC will speed
up nfsd_file initial opens.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfsd/filecache.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index fac98b2cb463a..ab9942e420543 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -1225,10 +1225,9 @@ nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
  * a file.  The security implications of this should be carefully
  * considered before use.
  *
- * The nfsd_file object returned by this API is reference-counted
- * and garbage-collected. The object is retained for a few
- * seconds after the final nfsd_file_put() in case the caller
- * wants to re-use it.
+ * The nfsd_file_object returned by this API is reference-counted
+ * but not garbage-collected. The object is unhashed after the
+ * final nfsd_file_put().
  *
  * Return values:
  *   %nfs_ok - @pnf points to an nfsd_file with its reference
@@ -1250,7 +1249,7 @@ nfsd_file_acquire_local(struct net *net, struct svc_cred *cred,
 	__be32 beres;
 
 	beres = nfsd_file_do_acquire(NULL, net, cred, client,
-				     fhp, may_flags, NULL, pnf, true);
+				     fhp, may_flags, NULL, pnf, false);
 	revert_creds(save_cred);
 	return beres;
 }
-- 
2.44.0

[for-6.13 PATCH v3 09/14] nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock

[Mike Snitzer]

This global spinlock protects all nfs_uuid_t relative to the global
nfs_uuids list.  A later commit will split this global spinlock so
prepare by renaming this lock to reflect its intended narrow scope.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
 fs/nfs_common/nfslocalio.c | 34 +++++++++++++++++-----------------
 fs/nfsd/localio.c          |  2 +-
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index e75cd21f4c8bc..5fa3f47b442e9 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -15,11 +15,11 @@
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("NFS localio protocol bypass support");
 
-static DEFINE_SPINLOCK(nfs_uuid_lock);
+static DEFINE_SPINLOCK(nfs_uuids_lock);
 
 /*
  * Global list of nfs_uuid_t instances
- * that is protected by nfs_uuid_lock.
+ * that is protected by nfs_uuids_lock.
  */
 static LIST_HEAD(nfs_uuids);
 
@@ -34,15 +34,15 @@ EXPORT_SYMBOL_GPL(nfs_uuid_init);
 
 bool nfs_uuid_begin(nfs_uuid_t *nfs_uuid)
 {
-	spin_lock(&nfs_uuid_lock);
+	spin_lock(&nfs_uuids_lock);
 	/* Is this nfs_uuid already in use? */
 	if (!list_empty(&nfs_uuid->list)) {
-		spin_unlock(&nfs_uuid_lock);
+		spin_unlock(&nfs_uuids_lock);
 		return false;
 	}
 	uuid_gen(&nfs_uuid->uuid);
 	list_add_tail(&nfs_uuid->list, &nfs_uuids);
-	spin_unlock(&nfs_uuid_lock);
+	spin_unlock(&nfs_uuids_lock);
 
 	return true;
 }
@@ -51,10 +51,10 @@ EXPORT_SYMBOL_GPL(nfs_uuid_begin);
 void nfs_uuid_end(nfs_uuid_t *nfs_uuid)
 {
 	if (nfs_uuid->net == NULL) {
-		spin_lock(&nfs_uuid_lock);
+		spin_lock(&nfs_uuids_lock);
 		if (nfs_uuid->net == NULL)
 			list_del_init(&nfs_uuid->list);
-		spin_unlock(&nfs_uuid_lock);
+		spin_unlock(&nfs_uuids_lock);
 	}
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_end);
@@ -78,7 +78,7 @@ void nfs_uuid_is_local(const uuid_t *uuid, struct list_head *list,
 {
 	nfs_uuid_t *nfs_uuid;
 
-	spin_lock(&nfs_uuid_lock);
+	spin_lock(&nfs_uuids_lock);
 	nfs_uuid = nfs_uuid_lookup_locked(uuid);
 	if (nfs_uuid) {
 		kref_get(&dom->ref);
@@ -94,7 +94,7 @@ void nfs_uuid_is_local(const uuid_t *uuid, struct list_head *list,
 		__module_get(mod);
 		nfsd_mod = mod;
 	}
-	spin_unlock(&nfs_uuid_lock);
+	spin_unlock(&nfs_uuids_lock);
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_is_local);
 
@@ -128,9 +128,9 @@ void nfs_localio_disable_client(struct nfs_client *clp)
 
 	spin_lock(&nfs_uuid->lock);
 	if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
-		spin_lock(&nfs_uuid_lock);
+		spin_lock(&nfs_uuids_lock);
 		nfs_uuid_put_locked(nfs_uuid);
-		spin_unlock(&nfs_uuid_lock);
+		spin_unlock(&nfs_uuids_lock);
 	}
 	spin_unlock(&nfs_uuid->lock);
 }
@@ -140,23 +140,23 @@ void nfs_localio_invalidate_clients(struct list_head *cl_uuid_list)
 {
 	nfs_uuid_t *nfs_uuid, *tmp;
 
-	spin_lock(&nfs_uuid_lock);
+	spin_lock(&nfs_uuids_lock);
 	list_for_each_entry_safe(nfs_uuid, tmp, cl_uuid_list, list) {
 		struct nfs_client *clp =
 			container_of(nfs_uuid, struct nfs_client, cl_uuid);
 
 		nfs_localio_disable_client(clp);
 	}
-	spin_unlock(&nfs_uuid_lock);
+	spin_unlock(&nfs_uuids_lock);
 }
 EXPORT_SYMBOL_GPL(nfs_localio_invalidate_clients);
 
 static void nfs_uuid_add_file(nfs_uuid_t *nfs_uuid, struct nfs_file_localio *nfl)
 {
-	spin_lock(&nfs_uuid_lock);
+	spin_lock(&nfs_uuids_lock);
 	if (!nfl->nfs_uuid)
 		rcu_assign_pointer(nfl->nfs_uuid, nfs_uuid);
-	spin_unlock(&nfs_uuid_lock);
+	spin_unlock(&nfs_uuids_lock);
 }
 
 /*
@@ -217,14 +217,14 @@ void nfs_close_local_fh(struct nfs_file_localio *nfl)
 	ro_nf = rcu_access_pointer(nfl->ro_file);
 	rw_nf = rcu_access_pointer(nfl->rw_file);
 	if (ro_nf || rw_nf) {
-		spin_lock(&nfs_uuid_lock);
+		spin_lock(&nfs_uuids_lock);
 		if (ro_nf)
 			ro_nf = rcu_dereference_protected(xchg(&nfl->ro_file, NULL), 1);
 		if (rw_nf)
 			rw_nf = rcu_dereference_protected(xchg(&nfl->rw_file, NULL), 1);
 
 		rcu_assign_pointer(nfl->nfs_uuid, NULL);
-		spin_unlock(&nfs_uuid_lock);
+		spin_unlock(&nfs_uuids_lock);
 		rcu_read_unlock();
 
 		if (ro_nf)
diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c
index f9a91cd3b5ec7..2ae07161b9195 100644
--- a/fs/nfsd/localio.c
+++ b/fs/nfsd/localio.c
@@ -54,7 +54,7 @@ void nfsd_localio_ops_init(void)
  * avoid all the NFS overhead with reads, writes and commits.
  *
  * On successful return, returned nfsd_file will have its nf_net member
- * set. Caller (NFS client) is responsible for calling nfsd_serv_put and
+ * set. Caller (NFS client) is responsible for calling nfsd_net_put and
  * nfsd_file_put (via nfs_to_nfsd_file_put_local).
  */
 struct nfsd_file *
-- 
2.44.0

[for-6.13 PATCH v3 10/14] nfs_common: track all open nfsd_files per LOCALIO nfs_client

[Mike Snitzer]

This tracking enables __nfsd_file_cache_purge() to call
nfs_localio_invalidate_clients(), upon shutdown or export change, to
nfs_close_local_fh() all open nfsd_files that are still cached by the
LOCALIO nfs clients associated with nfsd_net that is being shutdown.

Now that the client must track all open nfsd_files there was more work
than necessary being done with the global nfs_uuids_lock contended.
This manifested in various RCU issues, e.g.:
 hrtimer: interrupt took 47969440 ns
 rcu: INFO: rcu_sched detected stalls on CPUs/tasks:

Use nfs_uuid->lock to protect all nfs_uuid_t members, instead of
nfs_uuids_lock, once nfs_uuid_is_local() adds the client to
nn->local_clients.

Also add 'local_clients_lock' to 'struct nfsd_net' to protect
nn->local_clients.  And store a pointer to spinlock in the 'list_lock'
member of nfs_uuid_t so nfs_localio_disable_client() can use it to
avoid taking the global nfs_uuids_lock.

In combination, these split out locks eliminate the use of the single
nfslocalio.c global nfs_uuids_lock in the IO paths (open and close).

Also refactored associated fs/nfs_common/nfslocalio.c methods' locking
to reduce work performed with spinlocks held in general.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfs_common/nfslocalio.c | 168 +++++++++++++++++++++++++++----------
 fs/nfsd/filecache.c        |   9 ++
 fs/nfsd/localio.c          |   1 +
 fs/nfsd/netns.h            |   1 +
 fs/nfsd/nfsctl.c           |   4 +-
 include/linux/nfslocalio.h |   8 +-
 6 files changed, 144 insertions(+), 47 deletions(-)

diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index 5fa3f47b442e9..cfb61871fb1e0 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -23,27 +23,49 @@ static DEFINE_SPINLOCK(nfs_uuids_lock);
  */
 static LIST_HEAD(nfs_uuids);
 
+/*
+ * Lock ordering:
+ * 1: nfs_uuid->lock
+ * 2: nfs_uuids_lock
+ * 3: nfs_uuid->list_lock (aka nn->local_clients_lock)
+ *
+ * May skip locks in select cases, but never hold multiple
+ * locks out of order.
+ */
+
 void nfs_uuid_init(nfs_uuid_t *nfs_uuid)
 {
 	nfs_uuid->net = NULL;
 	nfs_uuid->dom = NULL;
+	nfs_uuid->list_lock = NULL;
 	INIT_LIST_HEAD(&nfs_uuid->list);
+	INIT_LIST_HEAD(&nfs_uuid->files);
 	spin_lock_init(&nfs_uuid->lock);
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_init);
 
 bool nfs_uuid_begin(nfs_uuid_t *nfs_uuid)
 {
+	spin_lock(&nfs_uuid->lock);
+	if (nfs_uuid->net) {
+		/* This nfs_uuid is already in use */
+		spin_unlock(&nfs_uuid->lock);
+		return false;
+	}
+
 	spin_lock(&nfs_uuids_lock);
-	/* Is this nfs_uuid already in use? */
 	if (!list_empty(&nfs_uuid->list)) {
+		/* This nfs_uuid is already in use */
 		spin_unlock(&nfs_uuids_lock);
+		spin_unlock(&nfs_uuid->lock);
 		return false;
 	}
-	uuid_gen(&nfs_uuid->uuid);
 	list_add_tail(&nfs_uuid->list, &nfs_uuids);
 	spin_unlock(&nfs_uuids_lock);
 
+	uuid_gen(&nfs_uuid->uuid);
+	spin_unlock(&nfs_uuid->lock);
+
 	return true;
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_begin);
@@ -51,11 +73,15 @@ EXPORT_SYMBOL_GPL(nfs_uuid_begin);
 void nfs_uuid_end(nfs_uuid_t *nfs_uuid)
 {
 	if (nfs_uuid->net == NULL) {
-		spin_lock(&nfs_uuids_lock);
-		if (nfs_uuid->net == NULL)
+		spin_lock(&nfs_uuid->lock);
+		if (nfs_uuid->net == NULL) {
+			/* Not local, remove from nfs_uuids */
+			spin_lock(&nfs_uuids_lock);
 			list_del_init(&nfs_uuid->list);
-		spin_unlock(&nfs_uuids_lock);
-	}
+			spin_unlock(&nfs_uuids_lock);
+		}
+		spin_unlock(&nfs_uuid->lock);
+        }
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_end);
 
@@ -73,28 +99,39 @@ static nfs_uuid_t * nfs_uuid_lookup_locked(const uuid_t *uuid)
 static struct module *nfsd_mod;
 
 void nfs_uuid_is_local(const uuid_t *uuid, struct list_head *list,
-		       struct net *net, struct auth_domain *dom,
-		       struct module *mod)
+		       spinlock_t *list_lock, struct net *net,
+		       struct auth_domain *dom, struct module *mod)
 {
 	nfs_uuid_t *nfs_uuid;
 
 	spin_lock(&nfs_uuids_lock);
 	nfs_uuid = nfs_uuid_lookup_locked(uuid);
-	if (nfs_uuid) {
-		kref_get(&dom->ref);
-		nfs_uuid->dom = dom;
-		/*
-		 * We don't hold a ref on the net, but instead put
-		 * ourselves on a list so the net pointer can be
-		 * invalidated.
-		 */
-		list_move(&nfs_uuid->list, list);
-		rcu_assign_pointer(nfs_uuid->net, net);
-
-		__module_get(mod);
-		nfsd_mod = mod;
+	if (!nfs_uuid) {
+		spin_unlock(&nfs_uuids_lock);
+		return;
 	}
+
+	/*
+	 * We don't hold a ref on the net, but instead put
+	 * ourselves on @list (nn->local_clients) so the net
+	 * pointer can be invalidated.
+	 */
+	spin_lock(list_lock); /* list_lock is nn->local_clients_lock */
+	list_move(&nfs_uuid->list, list);
+	spin_unlock(list_lock);
+
 	spin_unlock(&nfs_uuids_lock);
+	/* Once nfs_uuid is parented to @list, avoid global nfs_uuids_lock */
+	spin_lock(&nfs_uuid->lock);
+
+	__module_get(mod);
+	nfsd_mod = mod;
+
+	nfs_uuid->list_lock = list_lock;
+	kref_get(&dom->ref);
+	nfs_uuid->dom = dom;
+	rcu_assign_pointer(nfs_uuid->net, net);
+	spin_unlock(&nfs_uuid->lock);
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_is_local);
 
@@ -108,55 +145,96 @@ void nfs_localio_enable_client(struct nfs_client *clp)
 }
 EXPORT_SYMBOL_GPL(nfs_localio_enable_client);
 
-static void nfs_uuid_put_locked(nfs_uuid_t *nfs_uuid)
+/*
+ * Cleanup the nfs_uuid_t embedded in an nfs_client.
+ * This is the long-form of nfs_uuid_init().
+ */
+static void nfs_uuid_put(nfs_uuid_t *nfs_uuid)
 {
-	if (!nfs_uuid->net)
+	LIST_HEAD(local_files);
+	struct nfs_file_localio *nfl, *tmp;
+
+	spin_lock(&nfs_uuid->lock);
+	if (unlikely(!nfs_uuid->net)) {
+		spin_unlock(&nfs_uuid->lock);
 		return;
-	module_put(nfsd_mod);
+	}
 	RCU_INIT_POINTER(nfs_uuid->net, NULL);
 
 	if (nfs_uuid->dom) {
 		auth_domain_put(nfs_uuid->dom);
 		nfs_uuid->dom = NULL;
 	}
-	list_del_init(&nfs_uuid->list);
+
+	list_splice_init(&nfs_uuid->files, &local_files);
+	spin_unlock(&nfs_uuid->lock);
+
+	/* Walk list of files and ensure their last references dropped */
+	list_for_each_entry_safe(nfl, tmp, &local_files, list) {
+		nfs_close_local_fh(nfl);
+		cond_resched();
+	}
+
+	spin_lock(&nfs_uuid->lock);
+	BUG_ON(!list_empty(&nfs_uuid->files));
+
+	/* Remove client from nn->local_clients */
+	if (nfs_uuid->list_lock) {
+		spin_lock(nfs_uuid->list_lock);
+		BUG_ON(list_empty(&nfs_uuid->list));
+		list_del_init(&nfs_uuid->list);
+		spin_unlock(nfs_uuid->list_lock);
+		nfs_uuid->list_lock = NULL;
+	}
+
+	module_put(nfsd_mod);
+	spin_unlock(&nfs_uuid->lock);
 }
 
 void nfs_localio_disable_client(struct nfs_client *clp)
 {
-	nfs_uuid_t *nfs_uuid = &clp->cl_uuid;
+	nfs_uuid_t *nfs_uuid = NULL;
 
-	spin_lock(&nfs_uuid->lock);
+	spin_lock(&clp->cl_uuid.lock); /* aka &nfs_uuid->lock */
 	if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
-		spin_lock(&nfs_uuids_lock);
-		nfs_uuid_put_locked(nfs_uuid);
-		spin_unlock(&nfs_uuids_lock);
+		/* &clp->cl_uuid is always not NULL, using as bool here */
+		nfs_uuid = &clp->cl_uuid;
 	}
-	spin_unlock(&nfs_uuid->lock);
+	spin_unlock(&clp->cl_uuid.lock);
+
+	if (nfs_uuid)
+		nfs_uuid_put(nfs_uuid);
 }
 EXPORT_SYMBOL_GPL(nfs_localio_disable_client);
 
-void nfs_localio_invalidate_clients(struct list_head *cl_uuid_list)
+void nfs_localio_invalidate_clients(struct list_head *nn_local_clients,
+				    spinlock_t *nn_local_clients_lock)
 {
+	LIST_HEAD(local_clients);
 	nfs_uuid_t *nfs_uuid, *tmp;
+	struct nfs_client *clp;
 
-	spin_lock(&nfs_uuids_lock);
-	list_for_each_entry_safe(nfs_uuid, tmp, cl_uuid_list, list) {
-		struct nfs_client *clp =
-			container_of(nfs_uuid, struct nfs_client, cl_uuid);
-
+	spin_lock(nn_local_clients_lock);
+	list_splice_init(nn_local_clients, &local_clients);
+	spin_unlock(nn_local_clients_lock);
+	list_for_each_entry_safe(nfs_uuid, tmp, &local_clients, list) {
+		if (WARN_ON(nfs_uuid->list_lock != nn_local_clients_lock))
+			break;
+		clp = container_of(nfs_uuid, struct nfs_client, cl_uuid);
 		nfs_localio_disable_client(clp);
 	}
-	spin_unlock(&nfs_uuids_lock);
 }
 EXPORT_SYMBOL_GPL(nfs_localio_invalidate_clients);
 
 static void nfs_uuid_add_file(nfs_uuid_t *nfs_uuid, struct nfs_file_localio *nfl)
 {
-	spin_lock(&nfs_uuids_lock);
-	if (!nfl->nfs_uuid)
+	/* Add nfl to nfs_uuid->files if it isn't already */
+	spin_lock(&nfs_uuid->lock);
+	if (list_empty(&nfl->list)) {
 		rcu_assign_pointer(nfl->nfs_uuid, nfs_uuid);
-	spin_unlock(&nfs_uuids_lock);
+		list_add_tail(&nfl->list, &nfs_uuid->files);
+	}
+	spin_unlock(&nfs_uuid->lock);
 }
 
 /*
@@ -217,14 +295,16 @@ void nfs_close_local_fh(struct nfs_file_localio *nfl)
 	ro_nf = rcu_access_pointer(nfl->ro_file);
 	rw_nf = rcu_access_pointer(nfl->rw_file);
 	if (ro_nf || rw_nf) {
-		spin_lock(&nfs_uuids_lock);
+		spin_lock(&nfs_uuid->lock);
 		if (ro_nf)
 			ro_nf = rcu_dereference_protected(xchg(&nfl->ro_file, NULL), 1);
 		if (rw_nf)
 			rw_nf = rcu_dereference_protected(xchg(&nfl->rw_file, NULL), 1);
 
-		rcu_assign_pointer(nfl->nfs_uuid, NULL);
-		spin_unlock(&nfs_uuids_lock);
+		/* Remove nfl from nfs_uuid->files list */
+		RCU_INIT_POINTER(nfl->nfs_uuid, NULL);
+		list_del_init(&nfl->list);
+		spin_unlock(&nfs_uuid->lock);
 		rcu_read_unlock();
 
 		if (ro_nf)
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index ab9942e420543..c9ab64e3732ce 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -39,6 +39,7 @@
 #include <linux/fsnotify.h>
 #include <linux/seq_file.h>
 #include <linux/rhashtable.h>
+#include <linux/nfslocalio.h>
 
 #include "vfs.h"
 #include "nfsd.h"
@@ -836,6 +837,14 @@ __nfsd_file_cache_purge(struct net *net)
 	struct nfsd_file *nf;
 	LIST_HEAD(dispose);
 
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	if (net) {
+		struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+		nfs_localio_invalidate_clients(&nn->local_clients,
+					       &nn->local_clients_lock);
+	}
+#endif
+
 	rhltable_walk_enter(&nfsd_file_rhltable, &iter);
 	do {
 		rhashtable_walk_start(&iter);
diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c
index 2ae07161b9195..238647fa379e3 100644
--- a/fs/nfsd/localio.c
+++ b/fs/nfsd/localio.c
@@ -116,6 +116,7 @@ static __be32 localio_proc_uuid_is_local(struct svc_rqst *rqstp)
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
 	nfs_uuid_is_local(&argp->uuid, &nn->local_clients,
+			  &nn->local_clients_lock,
 			  net, rqstp->rq_client, THIS_MODULE);
 
 	return rpc_success;
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 8faef59d71229..187c4140b1913 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -220,6 +220,7 @@ struct nfsd_net {
 
 #if IS_ENABLED(CONFIG_NFS_LOCALIO)
 	/* Local clients to be invalidated when net is shut down */
+	spinlock_t              local_clients_lock;
 	struct list_head	local_clients;
 #endif
 };
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 727904d8a4d01..70347b0ecdc43 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -2259,6 +2259,7 @@ static __net_init int nfsd_net_init(struct net *net)
 	seqlock_init(&nn->writeverf_lock);
 	nfsd_proc_stat_init(net);
 #if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	spin_lock_init(&nn->local_clients_lock);
 	INIT_LIST_HEAD(&nn->local_clients);
 #endif
 	return 0;
@@ -2283,7 +2284,8 @@ static __net_exit void nfsd_net_pre_exit(struct net *net)
 {
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
-	nfs_localio_invalidate_clients(&nn->local_clients);
+	nfs_localio_invalidate_clients(&nn->local_clients,
+				       &nn->local_clients_lock);
 }
 #endif
 
diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index aa2b5c6561ab0..c68a529230c14 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -30,19 +30,23 @@ typedef struct {
 	/* sadly this struct is just over a cacheline, avoid bouncing */
 	spinlock_t ____cacheline_aligned lock;
 	struct list_head list;
+	spinlock_t *list_lock; /* nn->local_clients_lock */
 	struct net __rcu *net; /* nfsd's network namespace */
 	struct auth_domain *dom; /* auth_domain for localio */
+	/* Local files to close when net is shut down or exports change */
+	struct list_head files;
 } nfs_uuid_t;
 
 void nfs_uuid_init(nfs_uuid_t *);
 bool nfs_uuid_begin(nfs_uuid_t *);
 void nfs_uuid_end(nfs_uuid_t *);
-void nfs_uuid_is_local(const uuid_t *, struct list_head *,
+void nfs_uuid_is_local(const uuid_t *, struct list_head *, spinlock_t *,
 		       struct net *, struct auth_domain *, struct module *);
 
 void nfs_localio_enable_client(struct nfs_client *clp);
 void nfs_localio_disable_client(struct nfs_client *clp);
-void nfs_localio_invalidate_clients(struct list_head *list);
+void nfs_localio_invalidate_clients(struct list_head *nn_local_clients,
+				    spinlock_t *nn_local_clients_lock);
 
 /* localio needs to map filehandle -> struct nfsd_file */
 extern struct nfsd_file *
-- 
2.44.0

[for-6.13 PATCH v3 11/14] nfs_common: add nfs_localio trace events

[Mike Snitzer]

The nfs_localio.ko now exposes /sys/kernel/tracing/events/nfs_localio
with nfs_localio_enable_client and nfs_localio_disable_client events.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfs_common/Makefile        |  3 +-
 fs/nfs_common/localio_trace.c | 10 +++++++
 fs/nfs_common/localio_trace.h | 56 +++++++++++++++++++++++++++++++++++
 fs/nfs_common/nfslocalio.c    |  4 +++
 4 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 fs/nfs_common/localio_trace.c
 create mode 100644 fs/nfs_common/localio_trace.h

diff --git a/fs/nfs_common/Makefile b/fs/nfs_common/Makefile
index a5e54809701e3..c10ead273ff2c 100644
--- a/fs/nfs_common/Makefile
+++ b/fs/nfs_common/Makefile
@@ -6,8 +6,9 @@
 obj-$(CONFIG_NFS_ACL_SUPPORT) += nfs_acl.o
 nfs_acl-objs := nfsacl.o
 
+CFLAGS_localio_trace.o += -I$(src)
 obj-$(CONFIG_NFS_COMMON_LOCALIO_SUPPORT) += nfs_localio.o
-nfs_localio-objs := nfslocalio.o
+nfs_localio-objs := nfslocalio.o localio_trace.o
 
 obj-$(CONFIG_GRACE_PERIOD) += grace.o
 obj-$(CONFIG_NFS_V4_2_SSC_HELPER) += nfs_ssc.o
diff --git a/fs/nfs_common/localio_trace.c b/fs/nfs_common/localio_trace.c
new file mode 100644
index 0000000000000..7decfe57abebb
--- /dev/null
+++ b/fs/nfs_common/localio_trace.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024 Trond Myklebust <trond.myklebust@hammerspace.com>
+ * Copyright (C) 2024 Mike Snitzer <snitzer@hammerspace.com>
+ */
+#include <linux/nfs_fs.h>
+#include <linux/namei.h>
+
+#define CREATE_TRACE_POINTS
+#include "localio_trace.h"
diff --git a/fs/nfs_common/localio_trace.h b/fs/nfs_common/localio_trace.h
new file mode 100644
index 0000000000000..4055aec9ff8dc
--- /dev/null
+++ b/fs/nfs_common/localio_trace.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2024 Trond Myklebust <trond.myklebust@hammerspace.com>
+ * Copyright (C) 2024 Mike Snitzer <snitzer@hammerspace.com>
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM nfs_localio
+
+#if !defined(_TRACE_NFS_COMMON_LOCALIO_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_NFS_COMMON_LOCALIO_H
+
+#include <linux/tracepoint.h>
+
+#include <trace/misc/fs.h>
+#include <trace/misc/nfs.h>
+#include <trace/misc/sunrpc.h>
+
+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_localio_enable_client);
+DEFINE_NFS_LOCAL_CLIENT_EVENT(nfs_localio_disable_client);
+
+#endif /* _TRACE_NFS_COMMON_LOCALIO_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE localio_trace
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index cfb61871fb1e0..0decc2fe154c8 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -12,6 +12,8 @@
 #include <linux/nfs_fs.h>
 #include <net/netns/generic.h>
 
+#include "localio_trace.h"
+
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("NFS localio protocol bypass support");
 
@@ -141,6 +143,7 @@ void nfs_localio_enable_client(struct nfs_client *clp)
 
 	spin_lock(&nfs_uuid->lock);
 	set_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
+	trace_nfs_localio_enable_client(clp);
 	spin_unlock(&nfs_uuid->lock);
 }
 EXPORT_SYMBOL_GPL(nfs_localio_enable_client);
@@ -199,6 +202,7 @@ void nfs_localio_disable_client(struct nfs_client *clp)
 	if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
 		/* &clp->cl_uuid is always not NULL, using as bool here */
 		nfs_uuid = &clp->cl_uuid;
+		trace_nfs_localio_disable_client(clp);
 	}
 	spin_unlock(&clp->cl_uuid.lock);
 
-- 
2.44.0

[for-6.13 PATCH v3 12/14] nfs/localio: remove redundant code and simplify LOCALIO enablement

[Mike Snitzer]

Remove nfs_local_enable and nfs_local_disable, instead use
nfs_localio_enable_client and nfs_localio_disable_client.

Discontinue use of the NFS_CS_LOCAL_IO bit in the nfs_client struct's
cl_flags to reflect that LOCALIO is enabled; instead just test if the
net member of the nfs_uuid_t struct is set.

Also remove NFS_CS_LOCAL_IO.

Lastly, remove trace_nfs_local_enable and trace_nfs_local_disable
because comparable traces are available from nfs_localio.ko.

Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfs/client.c            |  4 ++--
 fs/nfs/internal.h          |  2 --
 fs/nfs/localio.c           | 28 +++++-----------------------
 fs/nfs/nfstrace.h          | 32 --------------------------------
 fs/nfs_common/nfslocalio.c | 34 +++++++++++-----------------------
 include/linux/nfs_fs_sb.h  |  1 -
 include/linux/nfslocalio.h |  4 ++++
 7 files changed, 22 insertions(+), 83 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index e83e1ce046130..16530c71fd152 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -38,7 +38,7 @@
 #include <linux/sunrpc/bc_xprt.h>
 #include <linux/nsproxy.h>
 #include <linux/pid_namespace.h>
-
+#include <linux/nfslocalio.h>
 
 #include "nfs4_fs.h"
 #include "callback.h"
@@ -243,7 +243,7 @@ static void pnfs_init_server(struct nfs_server *server)
  */
 void nfs_free_client(struct nfs_client *clp)
 {
-	nfs_local_disable(clp);
+	nfs_localio_disable_client(clp);
 
 	/* -EIO all pending I/O */
 	if (!IS_ERR(clp->cl_rpcclient))
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 57af3ab3adbe5..a252191b9335c 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -454,7 +454,6 @@ 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 nfsd_file *nfs_local_open_fh(struct nfs_client *,
 					   const struct cred *,
@@ -471,7 +470,6 @@ extern int nfs_local_commit(struct nfsd_file *,
 extern bool nfs_server_is_local(const struct nfs_client *clp);
 
 #else /* CONFIG_NFS_LOCALIO */
-static inline void nfs_local_disable(struct nfs_client *clp) {}
 static inline void nfs_local_probe(struct nfs_client *clp) {}
 static inline struct nfsd_file *
 nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 7e432057c3a1f..4b6bf4ea7d7fc 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -56,7 +56,7 @@ MODULE_PARM_DESC(localio_O_DIRECT_semantics,
 
 static inline bool nfs_client_is_local(const struct nfs_client *clp)
 {
-	return !!test_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
+	return !!rcu_access_pointer(clp->cl_uuid.net);
 }
 
 bool nfs_server_is_local(const struct nfs_client *clp)
@@ -121,24 +121,6 @@ const struct rpc_program nfslocalio_program = {
 	.stats			= &nfslocalio_rpcstat,
 };
 
-/*
- * nfs_local_enable - enable local i/o for an nfs_client
- */
-static void nfs_local_enable(struct nfs_client *clp)
-{
-	trace_nfs_local_enable(clp);
-	nfs_localio_enable_client(clp);
-}
-
-/*
- * nfs_local_disable - disable local i/o for an nfs_client
- */
-void nfs_local_disable(struct nfs_client *clp)
-{
-	trace_nfs_local_disable(clp);
-	nfs_localio_disable_client(clp);
-}
-
 /*
  * nfs_init_localioclient - Initialise an NFS localio client connection
  */
@@ -194,19 +176,19 @@ void nfs_local_probe(struct nfs_client *clp)
 	/* Disallow localio if disabled via sysfs or AUTH_SYS isn't used */
 	if (!localio_enabled ||
 	    clp->cl_rpcclient->cl_auth->au_flavor != RPC_AUTH_UNIX) {
-		nfs_local_disable(clp);
+		nfs_localio_disable_client(clp);
 		return;
 	}
 
 	if (nfs_client_is_local(clp)) {
 		/* If already enabled, disable and re-enable */
-		nfs_local_disable(clp);
+		nfs_localio_disable_client(clp);
 	}
 
 	if (!nfs_uuid_begin(&clp->cl_uuid))
 		return;
 	if (nfs_server_uuid_is_local(clp))
-		nfs_local_enable(clp);
+		nfs_localio_enable_client(clp);
 	nfs_uuid_end(&clp->cl_uuid);
 }
 EXPORT_SYMBOL_GPL(nfs_local_probe);
@@ -748,7 +730,7 @@ int nfs_local_doio(struct nfs_client *clp, struct nfsd_file *localio,
 
 	if (status != 0) {
 		if (status == -EAGAIN)
-			nfs_local_disable(clp);
+			nfs_localio_disable_client(clp);
 		nfs_local_file_put(localio);
 		hdr->task.tk_status = status;
 		nfs_local_hdr_release(hdr, call_ops);
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index 1eab98c277fab..7a058bd8c566e 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -1714,38 +1714,6 @@ TRACE_EVENT(nfs_local_open_fh,
 		)
 );
 
-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_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index 0decc2fe154c8..bad7691e32b94 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -37,7 +37,7 @@ static LIST_HEAD(nfs_uuids);
 
 void nfs_uuid_init(nfs_uuid_t *nfs_uuid)
 {
-	nfs_uuid->net = NULL;
+	RCU_INIT_POINTER(nfs_uuid->net, NULL);
 	nfs_uuid->dom = NULL;
 	nfs_uuid->list_lock = NULL;
 	INIT_LIST_HEAD(&nfs_uuid->list);
@@ -49,7 +49,7 @@ EXPORT_SYMBOL_GPL(nfs_uuid_init);
 bool nfs_uuid_begin(nfs_uuid_t *nfs_uuid)
 {
 	spin_lock(&nfs_uuid->lock);
-	if (nfs_uuid->net) {
+	if (rcu_access_pointer(nfs_uuid->net)) {
 		/* This nfs_uuid is already in use */
 		spin_unlock(&nfs_uuid->lock);
 		return false;
@@ -74,9 +74,9 @@ EXPORT_SYMBOL_GPL(nfs_uuid_begin);
 
 void nfs_uuid_end(nfs_uuid_t *nfs_uuid)
 {
-	if (nfs_uuid->net == NULL) {
+	if (!rcu_access_pointer(nfs_uuid->net)) {
 		spin_lock(&nfs_uuid->lock);
-		if (nfs_uuid->net == NULL) {
+		if (!rcu_access_pointer(nfs_uuid->net)) {
 			/* Not local, remove from nfs_uuids */
 			spin_lock(&nfs_uuids_lock);
 			list_del_init(&nfs_uuid->list);
@@ -139,12 +139,8 @@ EXPORT_SYMBOL_GPL(nfs_uuid_is_local);
 
 void nfs_localio_enable_client(struct nfs_client *clp)
 {
-	nfs_uuid_t *nfs_uuid = &clp->cl_uuid;
-
-	spin_lock(&nfs_uuid->lock);
-	set_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
+	/* nfs_uuid_is_local() does the actual enablement */
 	trace_nfs_localio_enable_client(clp);
-	spin_unlock(&nfs_uuid->lock);
 }
 EXPORT_SYMBOL_GPL(nfs_localio_enable_client);
 
@@ -152,15 +148,15 @@ EXPORT_SYMBOL_GPL(nfs_localio_enable_client);
  * Cleanup the nfs_uuid_t embedded in an nfs_client.
  * This is the long-form of nfs_uuid_init().
  */
-static void nfs_uuid_put(nfs_uuid_t *nfs_uuid)
+static bool nfs_uuid_put(nfs_uuid_t *nfs_uuid)
 {
 	LIST_HEAD(local_files);
 	struct nfs_file_localio *nfl, *tmp;
 
 	spin_lock(&nfs_uuid->lock);
-	if (unlikely(!nfs_uuid->net)) {
+	if (unlikely(!rcu_access_pointer(nfs_uuid->net))) {
 		spin_unlock(&nfs_uuid->lock);
-		return;
+		return false;
 	}
 	RCU_INIT_POINTER(nfs_uuid->net, NULL);
 
@@ -192,22 +188,14 @@ static void nfs_uuid_put(nfs_uuid_t *nfs_uuid)
 
 	module_put(nfsd_mod);
 	spin_unlock(&nfs_uuid->lock);
+
+	return true;
 }
 
 void nfs_localio_disable_client(struct nfs_client *clp)
 {
-	nfs_uuid_t *nfs_uuid = NULL;
-
-	spin_lock(&clp->cl_uuid.lock); /* aka &nfs_uuid->lock */
-	if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
-		/* &clp->cl_uuid is always not NULL, using as bool here */
-		nfs_uuid = &clp->cl_uuid;
+	if (nfs_uuid_put(&clp->cl_uuid))
 		trace_nfs_localio_disable_client(clp);
-	}
-	spin_unlock(&clp->cl_uuid.lock);
-
-	if (nfs_uuid)
-		nfs_uuid_put(nfs_uuid);
 }
 EXPORT_SYMBOL_GPL(nfs_localio_disable_client);
 
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 239d86ef166c0..ed66df1093e89 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -50,7 +50,6 @@ 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 */
diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index c68a529230c14..05817d6ef3d1e 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -111,6 +111,10 @@ static inline void nfs_close_local_fh(struct nfs_file_localio *nfl)
 static inline void nfsd_localio_ops_init(void)
 {
 }
+struct nfs_client;
+static inline void nfs_localio_disable_client(struct nfs_client *clp)
+{
+}
 
 #endif  /* CONFIG_NFS_LOCALIO */
 
-- 
2.44.0

[for-6.13 PATCH v3 13/14] nfs: probe for LOCALIO when v4 client reconnects to server

[Mike Snitzer]

Introduce nfs_local_probe_async() for the NFS client to initiate
if/when it reconnects with server. For NFSv4 it is a simple matter to
call nfs_local_probe_async() from nfs4_do_reclaim (during NFSv4
grace).

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfs/client.c           |  1 +
 fs/nfs/internal.h         |  3 +++
 fs/nfs/localio.c          | 14 ++++++++++++++
 fs/nfs/nfs4state.c        |  1 +
 include/linux/nfs_fs_sb.h |  1 +
 5 files changed, 20 insertions(+)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 16530c71fd152..3b0918ade53cd 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -186,6 +186,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
 	seqlock_init(&clp->cl_boot_lock);
 	ktime_get_real_ts64(&clp->cl_nfssvc_boot);
 	nfs_uuid_init(&clp->cl_uuid);
+	INIT_WORK(&clp->cl_local_probe_work, nfs_local_probe_async_work);
 #endif /* CONFIG_NFS_LOCALIO */
 
 	clp->cl_principal = "*";
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index a252191b9335c..ad9c56bc977bf 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -455,6 +455,8 @@ 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_probe(struct nfs_client *);
+extern void nfs_local_probe_async(struct nfs_client *);
+extern void nfs_local_probe_async_work(struct work_struct *);
 extern struct nfsd_file *nfs_local_open_fh(struct nfs_client *,
 					   const struct cred *,
 					   struct nfs_fh *,
@@ -471,6 +473,7 @@ extern bool nfs_server_is_local(const struct nfs_client *clp);
 
 #else /* CONFIG_NFS_LOCALIO */
 static inline void nfs_local_probe(struct nfs_client *clp) {}
+static inline void nfs_local_probe_async(struct nfs_client *clp) {}
 static inline struct nfsd_file *
 nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
 		  struct nfs_fh *fh, struct nfs_file_localio *nfl,
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 4b6bf4ea7d7fc..1eee5aac28843 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -193,6 +193,20 @@ void nfs_local_probe(struct nfs_client *clp)
 }
 EXPORT_SYMBOL_GPL(nfs_local_probe);
 
+void nfs_local_probe_async_work(struct work_struct *work)
+{
+	struct nfs_client *clp =
+		container_of(work, struct nfs_client, cl_local_probe_work);
+
+	nfs_local_probe(clp);
+}
+
+void nfs_local_probe_async(struct nfs_client *clp)
+{
+	queue_work(nfsiod_workqueue, &clp->cl_local_probe_work);
+}
+EXPORT_SYMBOL_GPL(nfs_local_probe_async);
+
 static inline struct nfsd_file *nfs_local_file_get(struct nfsd_file *nf)
 {
 	return nfs_to->nfsd_file_get(nf);
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 9a9f60a2291b4..542cdf71229fe 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1955,6 +1955,7 @@ static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recov
 	}
 	rcu_read_unlock();
 	nfs4_free_state_owners(&freeme);
+	nfs_local_probe_async(clp);
 	if (lost_locks)
 		pr_warn("NFS: %s: lost %d locks\n",
 			clp->cl_hostname, lost_locks);
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index ed66df1093e89..f00bfcee7120e 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -131,6 +131,7 @@ struct nfs_client {
 	struct timespec64	cl_nfssvc_boot;
 	seqlock_t		cl_boot_lock;
 	nfs_uuid_t		cl_uuid;
+	struct work_struct	cl_local_probe_work;
 #endif /* CONFIG_NFS_LOCALIO */
 };
 
-- 
2.44.0

[for-6.13 PATCH v3 14/14] nfs: probe for LOCALIO when v3 client reconnects to server

[Mike Snitzer]

Re-enabling NFSv3 LOCALIO is made more complex (than NFSv4) because v3
is stateless.  As such, the hueristic used to identify a LOCALIO probe
point is more adhoc by nature: if/when NFSv3 client IO begins to
complete again in terms of normal RPC-based NFSv3 server IO, attempt
nfs_local_probe_async().

Care is taken to throttle the frequency of nfs_local_probe_async(),
otherwise there could be a flood of repeat calls to
nfs_local_probe_async().

The throttle is admin controlled using a new module parameter for
nfsv3, e.g.:
  echo 512 > /sys/module/nfsv3/parameters/nfs3_localio_probe_throttle

Probe for NFSv3 LOCALIO every N IO requests (512 in this case). Must
be power-of-2, defaults to 0 (probing disabled).

On systems that expect to use LOCALIO with NFSv3 the admin should
configure the 'nfs3_localio_probe_throttle' module parameter.

This commit backfills module parameter documentation in localio.rst

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 Documentation/filesystems/nfs/localio.rst | 20 +++++++++-
 fs/nfs/nfs3proc.c                         | 46 +++++++++++++++++++++--
 fs/nfs_common/nfslocalio.c                |  1 +
 include/linux/nfslocalio.h                |  3 +-
 4 files changed, 65 insertions(+), 5 deletions(-)

diff --git a/Documentation/filesystems/nfs/localio.rst b/Documentation/filesystems/nfs/localio.rst
index 9d991a958c81c..4b14c1e326731 100644
--- a/Documentation/filesystems/nfs/localio.rst
+++ b/Documentation/filesystems/nfs/localio.rst
@@ -289,7 +289,7 @@ align their IO).
 Security
 ========
 
-Localio is only supported when UNIX-style authentication (AUTH_UNIX, aka
+LOCALIO is only supported when UNIX-style authentication (AUTH_UNIX, aka
 AUTH_SYS) is used.
 
 Care is taken to ensure the same NFS security mechanisms are used
@@ -304,6 +304,24 @@ client is afforded this same level of access (albeit in terms of the NFS
 protocol via SUNRPC). No other namespaces (user, mount, etc) have been
 altered or purposely extended from the server to the client.
 
+Module Parameters
+=================
+
+/sys/module/nfs/parameters/localio_enabled (bool)
+controls if LOCALIO is enabled, defaults to Y. If client and server are
+local but 'localio_enabled' is set to N then LOCALIO will not be used.
+
+/sys/module/nfs/parameters/localio_O_DIRECT_semantics (bool)
+controls if O_DIRECT extends down to the underlying filesystem, defaults
+to N. Application IO must be logical blocksize aligned, otherwise
+O_DIRECT will fail.
+
+/sys/module/nfsv3/parameters/nfs3_localio_probe_throttle (uint)
+controls if NFSv3 read and write IOs will trigger (re)enabling of
+LOCALIO every N (nfs3_localio_probe_throttle) IOs, defaults to 0
+(disabled). Must be power-of-2, admin keeps all the pieces if they
+misconfigure (too low a value or non-power-of-2).
+
 Testing
 =======
 
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 1566163c6d85b..7359e1a3bd84c 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -844,6 +844,41 @@ nfs3_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
 	return status;
 }
 
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+
+static unsigned nfs3_localio_probe_throttle __read_mostly = 0;
+module_param(nfs3_localio_probe_throttle, uint, 0644);
+MODULE_PARM_DESC(nfs3_localio_probe_throttle,
+		 "Probe for NFSv3 LOCALIO every N IO requests. Must be power-of-2, defaults to 0 (probing disabled).");
+
+static void nfs3_localio_probe(struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+
+	/* Throttled to reduce nfs_local_probe_async() frequency */
+	if (!nfs3_localio_probe_throttle || nfs_server_is_local(clp))
+		return;
+
+	/*
+	 * Try (re)enabling LOCALIO if isn't enabled -- admin deems
+	 * it worthwhile to periodically check if LOCALIO possible by
+	 * setting the 'nfs3_localio_probe_throttle' module parameter.
+	 *
+	 * This is useful if LOCALIO was previously enabled, but was
+	 * disabled due to server restart, and IO has successfully
+	 * completed in terms of normal RPC.
+	 */
+	if ((clp->cl_uuid.nfs3_localio_probe_count++ &
+	     (nfs3_localio_probe_throttle - 1)) == 0) {
+		if (!nfs_server_is_local(clp))
+			nfs_local_probe_async(clp);
+	}
+}
+
+#else
+static void nfs3_localio_probe(struct nfs_server *server) {}
+#endif
+
 static int nfs3_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
 {
 	struct inode *inode = hdr->inode;
@@ -855,8 +890,11 @@ static int nfs3_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
 	if (nfs3_async_handle_jukebox(task, inode))
 		return -EAGAIN;
 
-	if (task->tk_status >= 0 && !server->read_hdrsize)
-		cmpxchg(&server->read_hdrsize, 0, hdr->res.replen);
+	if (task->tk_status >= 0) {
+		if (!server->read_hdrsize)
+			cmpxchg(&server->read_hdrsize, 0, hdr->res.replen);
+		nfs3_localio_probe(server);
+	}
 
 	nfs_invalidate_atime(inode);
 	nfs_refresh_inode(inode, &hdr->fattr);
@@ -886,8 +924,10 @@ static int nfs3_write_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
 
 	if (nfs3_async_handle_jukebox(task, inode))
 		return -EAGAIN;
-	if (task->tk_status >= 0)
+	if (task->tk_status >= 0) {
 		nfs_writeback_update_inode(hdr);
+		nfs3_localio_probe(NFS_SERVER(inode));
+	}
 	return 0;
 }
 
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index bad7691e32b94..6a0bdea6d6449 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -43,6 +43,7 @@ void nfs_uuid_init(nfs_uuid_t *nfs_uuid)
 	INIT_LIST_HEAD(&nfs_uuid->list);
 	INIT_LIST_HEAD(&nfs_uuid->files);
 	spin_lock_init(&nfs_uuid->lock);
+	nfs_uuid->nfs3_localio_probe_count = 0;
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_init);
 
diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index 05817d6ef3d1e..9aa8a43843d71 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -27,7 +27,8 @@ struct nfs_file_localio;
  */
 typedef struct {
 	uuid_t uuid;
-	/* sadly this struct is just over a cacheline, avoid bouncing */
+	unsigned nfs3_localio_probe_count;
+	/* this struct is over a cacheline, avoid bouncing */
 	spinlock_t ____cacheline_aligned lock;
 	struct list_head list;
 	spinlock_t *list_lock; /* nn->local_clients_lock */
-- 
2.44.0

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Jeff Layton]

On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
> Hi,
> 
> All available here:
> https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
> 
> Changes since v2:
> - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
>   NULL.
> - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
> - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
>   'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
>   LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
>   'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
> - added "Module Parameters" section to localio.rst
> 
> All review appreciated, thanks.
> Mike
> 
> Mike Snitzer (14):
>   nfs/localio: add direct IO enablement with sync and async IO support
>   nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
>   nfs_common: rename functions that invalidate LOCALIO nfs_clients
>   nfs_common: move localio_lock to new lock member of nfs_uuid_t
>   nfs: cache all open LOCALIO nfsd_file(s) in client
>   nfsd: update percpu_ref to manage references on nfsd_net
>   nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
>   nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
>   nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
>   nfs_common: track all open nfsd_files per LOCALIO nfs_client
>   nfs_common: add nfs_localio trace events
>   nfs/localio: remove redundant code and simplify LOCALIO enablement
>   nfs: probe for LOCALIO when v4 client reconnects to server
>   nfs: probe for LOCALIO when v3 client reconnects to server
> 
>  Documentation/filesystems/nfs/localio.rst |  98 +++++----
>  fs/nfs/client.c                           |   6 +-
>  fs/nfs/direct.c                           |   1 +
>  fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
>  fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
>  fs/nfs/inode.c                            |   3 +
>  fs/nfs/internal.h                         |   9 +-
>  fs/nfs/localio.c                          | 232 +++++++++++++++-----
>  fs/nfs/nfs3proc.c                         |  46 +++-
>  fs/nfs/nfs4state.c                        |   1 +
>  fs/nfs/nfstrace.h                         |  32 ---
>  fs/nfs/pagelist.c                         |   5 +-
>  fs/nfs/write.c                            |   3 +-
>  fs/nfs_common/Makefile                    |   3 +-
>  fs/nfs_common/localio_trace.c             |  10 +
>  fs/nfs_common/localio_trace.h             |  56 +++++
>  fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
>  fs/nfsd/filecache.c                       |  20 +-
>  fs/nfsd/localio.c                         |   9 +-
>  fs/nfsd/netns.h                           |  12 +-
>  fs/nfsd/nfsctl.c                          |   6 +-
>  fs/nfsd/nfssvc.c                          |  40 ++--
>  include/linux/nfs_fs.h                    |  22 +-
>  include/linux/nfs_fs_sb.h                 |   3 +-
>  include/linux/nfs_xdr.h                   |   1 +
>  include/linux/nfslocalio.h                |  48 +++--
>  26 files changed, 674 insertions(+), 268 deletions(-)
>  create mode 100644 fs/nfs_common/localio_trace.c
>  create mode 100644 fs/nfs_common/localio_trace.h
> 

I went through the set and it looks mostly sane to me. The one concern
I have is that you have the client set up to start caching nfsd files
before there is a mechanism to call it and ask them to return them. You
might see some weird behavior there on a bisect, but it looks like it
all gets resolved in the end.

How do you intend for this to go in? Since most of this is client side,
will this be going in via Trond/Anna's tree?

You can add:

Reviewed-by: Jeff Layton <jlayton@kernel.org>

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Mike Snitzer]

On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
> On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
> > Hi,
> > 
> > All available here:
> > https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
> > 
> > Changes since v2:
> > - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
> >   NULL.
> > - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
> > - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
> >   'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
> >   LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
> >   'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
> > - added "Module Parameters" section to localio.rst
> > 
> > All review appreciated, thanks.
> > Mike
> > 
> > Mike Snitzer (14):
> >   nfs/localio: add direct IO enablement with sync and async IO support
> >   nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
> >   nfs_common: rename functions that invalidate LOCALIO nfs_clients
> >   nfs_common: move localio_lock to new lock member of nfs_uuid_t
> >   nfs: cache all open LOCALIO nfsd_file(s) in client
> >   nfsd: update percpu_ref to manage references on nfsd_net
> >   nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
> >   nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
> >   nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
> >   nfs_common: track all open nfsd_files per LOCALIO nfs_client
> >   nfs_common: add nfs_localio trace events
> >   nfs/localio: remove redundant code and simplify LOCALIO enablement
> >   nfs: probe for LOCALIO when v4 client reconnects to server
> >   nfs: probe for LOCALIO when v3 client reconnects to server
> > 
> >  Documentation/filesystems/nfs/localio.rst |  98 +++++----
> >  fs/nfs/client.c                           |   6 +-
> >  fs/nfs/direct.c                           |   1 +
> >  fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
> >  fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
> >  fs/nfs/inode.c                            |   3 +
> >  fs/nfs/internal.h                         |   9 +-
> >  fs/nfs/localio.c                          | 232 +++++++++++++++-----
> >  fs/nfs/nfs3proc.c                         |  46 +++-
> >  fs/nfs/nfs4state.c                        |   1 +
> >  fs/nfs/nfstrace.h                         |  32 ---
> >  fs/nfs/pagelist.c                         |   5 +-
> >  fs/nfs/write.c                            |   3 +-
> >  fs/nfs_common/Makefile                    |   3 +-
> >  fs/nfs_common/localio_trace.c             |  10 +
> >  fs/nfs_common/localio_trace.h             |  56 +++++
> >  fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
> >  fs/nfsd/filecache.c                       |  20 +-
> >  fs/nfsd/localio.c                         |   9 +-
> >  fs/nfsd/netns.h                           |  12 +-
> >  fs/nfsd/nfsctl.c                          |   6 +-
> >  fs/nfsd/nfssvc.c                          |  40 ++--
> >  include/linux/nfs_fs.h                    |  22 +-
> >  include/linux/nfs_fs_sb.h                 |   3 +-
> >  include/linux/nfs_xdr.h                   |   1 +
> >  include/linux/nfslocalio.h                |  48 +++--
> >  26 files changed, 674 insertions(+), 268 deletions(-)
> >  create mode 100644 fs/nfs_common/localio_trace.c
> >  create mode 100644 fs/nfs_common/localio_trace.h
> > 
> 
> I went through the set and it looks mostly sane to me. The one concern
> I have is that you have the client set up to start caching nfsd files
> before there is a mechanism to call it and ask them to return them. You
> might see some weird behavior there on a bisect, but it looks like it
> all gets resolved in the end.

Yeah, couldn't see a better way to atomically pivot to the new disable
functionality without it needing to be a large muddled patch.

Shouldn't be bad even if someone did bisect, its only the server being
restarted during LOCALIO that could see issues (unlikely thing for
someone to be testing for specifically with a bisect).

> How do you intend for this to go in? Since most of this is client side,
> will this be going in via Trond/Anna's tree?

Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
did have it in his testing tree, maybe your Reviewed-by helps it all
land.

> You can add:
> 
> Reviewed-by: Jeff Layton <jlayton@kernel.org>

Thanks,
Mike

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Mike Snitzer]

On Fri, Nov 22, 2024 at 09:31:23PM -0500, Mike Snitzer wrote:
> On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
> > On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
> > > Hi,
> > > 
> > > All available here:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
> > > 
> > > Changes since v2:
> > > - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
> > >   NULL.
> > > - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
> > > - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
> > >   'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
> > >   LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
> > >   'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
> > > - added "Module Parameters" section to localio.rst
> > > 
> > > All review appreciated, thanks.
> > > Mike
> > > 
> > > Mike Snitzer (14):
> > >   nfs/localio: add direct IO enablement with sync and async IO support
> > >   nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
> > >   nfs_common: rename functions that invalidate LOCALIO nfs_clients
> > >   nfs_common: move localio_lock to new lock member of nfs_uuid_t
> > >   nfs: cache all open LOCALIO nfsd_file(s) in client
> > >   nfsd: update percpu_ref to manage references on nfsd_net
> > >   nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
> > >   nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
> > >   nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
> > >   nfs_common: track all open nfsd_files per LOCALIO nfs_client
> > >   nfs_common: add nfs_localio trace events
> > >   nfs/localio: remove redundant code and simplify LOCALIO enablement
> > >   nfs: probe for LOCALIO when v4 client reconnects to server
> > >   nfs: probe for LOCALIO when v3 client reconnects to server
> > > 
> > >  Documentation/filesystems/nfs/localio.rst |  98 +++++----
> > >  fs/nfs/client.c                           |   6 +-
> > >  fs/nfs/direct.c                           |   1 +
> > >  fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
> > >  fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
> > >  fs/nfs/inode.c                            |   3 +
> > >  fs/nfs/internal.h                         |   9 +-
> > >  fs/nfs/localio.c                          | 232 +++++++++++++++-----
> > >  fs/nfs/nfs3proc.c                         |  46 +++-
> > >  fs/nfs/nfs4state.c                        |   1 +
> > >  fs/nfs/nfstrace.h                         |  32 ---
> > >  fs/nfs/pagelist.c                         |   5 +-
> > >  fs/nfs/write.c                            |   3 +-
> > >  fs/nfs_common/Makefile                    |   3 +-
> > >  fs/nfs_common/localio_trace.c             |  10 +
> > >  fs/nfs_common/localio_trace.h             |  56 +++++
> > >  fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
> > >  fs/nfsd/filecache.c                       |  20 +-
> > >  fs/nfsd/localio.c                         |   9 +-
> > >  fs/nfsd/netns.h                           |  12 +-
> > >  fs/nfsd/nfsctl.c                          |   6 +-
> > >  fs/nfsd/nfssvc.c                          |  40 ++--
> > >  include/linux/nfs_fs.h                    |  22 +-
> > >  include/linux/nfs_fs_sb.h                 |   3 +-
> > >  include/linux/nfs_xdr.h                   |   1 +
> > >  include/linux/nfslocalio.h                |  48 +++--
> > >  26 files changed, 674 insertions(+), 268 deletions(-)
> > >  create mode 100644 fs/nfs_common/localio_trace.c
> > >  create mode 100644 fs/nfs_common/localio_trace.h
> > > 
> > 
> > I went through the set and it looks mostly sane to me. The one concern
> > I have is that you have the client set up to start caching nfsd files
> > before there is a mechanism to call it and ask them to return them. You
> > might see some weird behavior there on a bisect, but it looks like it
> > all gets resolved in the end.
> 
> Yeah, couldn't see a better way to atomically pivot to the new disable
> functionality without it needing to be a large muddled patch.
> 
> Shouldn't be bad even if someone did bisect, its only the server being
> restarted during LOCALIO that could see issues (unlikely thing for
> someone to be testing for specifically with a bisect).
> 
> > How do you intend for this to go in? Since most of this is client side,
> > will this be going in via Trond/Anna's tree?
> 
> Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
> did have it in his testing tree, maybe your Reviewed-by helps it all
> land.
> 
> > You can add:
> > 
> > Reviewed-by: Jeff Layton <jlayton@kernel.org>
> 
> Thanks,
> Mike
> 

Hi all,

These LOCALIO changes didn't land for 6.13 merge, please advise on if
we might get these changes staged for 6.14 now-ish.

Trond and/or Anna, do you feel comfortable picking this series up
(nfsd cachnges too) or would you like to see any changes before that
is possible?

Thanks,
Mike

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Anna Schumaker]

On 12/18/24 12:31 PM, Mike Snitzer wrote:
> On Fri, Nov 22, 2024 at 09:31:23PM -0500, Mike Snitzer wrote:
>> On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
>>> On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
>>>> Hi,
>>>>
>>>> All available here:
>>>> https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
>>>>
>>>> Changes since v2:
>>>> - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
>>>>   NULL.
>>>> - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
>>>> - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
>>>>   'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
>>>>   LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
>>>>   'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
>>>> - added "Module Parameters" section to localio.rst
>>>>
>>>> All review appreciated, thanks.
>>>> Mike
>>>>
>>>> Mike Snitzer (14):
>>>>   nfs/localio: add direct IO enablement with sync and async IO support
>>>>   nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
>>>>   nfs_common: rename functions that invalidate LOCALIO nfs_clients
>>>>   nfs_common: move localio_lock to new lock member of nfs_uuid_t
>>>>   nfs: cache all open LOCALIO nfsd_file(s) in client
>>>>   nfsd: update percpu_ref to manage references on nfsd_net
>>>>   nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
>>>>   nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
>>>>   nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
>>>>   nfs_common: track all open nfsd_files per LOCALIO nfs_client
>>>>   nfs_common: add nfs_localio trace events
>>>>   nfs/localio: remove redundant code and simplify LOCALIO enablement
>>>>   nfs: probe for LOCALIO when v4 client reconnects to server
>>>>   nfs: probe for LOCALIO when v3 client reconnects to server
>>>>
>>>>  Documentation/filesystems/nfs/localio.rst |  98 +++++----
>>>>  fs/nfs/client.c                           |   6 +-
>>>>  fs/nfs/direct.c                           |   1 +
>>>>  fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
>>>>  fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
>>>>  fs/nfs/inode.c                            |   3 +
>>>>  fs/nfs/internal.h                         |   9 +-
>>>>  fs/nfs/localio.c                          | 232 +++++++++++++++-----
>>>>  fs/nfs/nfs3proc.c                         |  46 +++-
>>>>  fs/nfs/nfs4state.c                        |   1 +
>>>>  fs/nfs/nfstrace.h                         |  32 ---
>>>>  fs/nfs/pagelist.c                         |   5 +-
>>>>  fs/nfs/write.c                            |   3 +-
>>>>  fs/nfs_common/Makefile                    |   3 +-
>>>>  fs/nfs_common/localio_trace.c             |  10 +
>>>>  fs/nfs_common/localio_trace.h             |  56 +++++
>>>>  fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
>>>>  fs/nfsd/filecache.c                       |  20 +-
>>>>  fs/nfsd/localio.c                         |   9 +-
>>>>  fs/nfsd/netns.h                           |  12 +-
>>>>  fs/nfsd/nfsctl.c                          |   6 +-
>>>>  fs/nfsd/nfssvc.c                          |  40 ++--
>>>>  include/linux/nfs_fs.h                    |  22 +-
>>>>  include/linux/nfs_fs_sb.h                 |   3 +-
>>>>  include/linux/nfs_xdr.h                   |   1 +
>>>>  include/linux/nfslocalio.h                |  48 +++--
>>>>  26 files changed, 674 insertions(+), 268 deletions(-)
>>>>  create mode 100644 fs/nfs_common/localio_trace.c
>>>>  create mode 100644 fs/nfs_common/localio_trace.h
>>>>
>>>
>>> I went through the set and it looks mostly sane to me. The one concern
>>> I have is that you have the client set up to start caching nfsd files
>>> before there is a mechanism to call it and ask them to return them. You
>>> might see some weird behavior there on a bisect, but it looks like it
>>> all gets resolved in the end.
>>
>> Yeah, couldn't see a better way to atomically pivot to the new disable
>> functionality without it needing to be a large muddled patch.
>>
>> Shouldn't be bad even if someone did bisect, its only the server being
>> restarted during LOCALIO that could see issues (unlikely thing for
>> someone to be testing for specifically with a bisect).
>>
>>> How do you intend for this to go in? Since most of this is client side,
>>> will this be going in via Trond/Anna's tree?
>>
>> Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
>> did have it in his testing tree, maybe your Reviewed-by helps it all
>> land.
>>
>>> You can add:
>>>
>>> Reviewed-by: Jeff Layton <jlayton@kernel.org>
>>
>> Thanks,
>> Mike
>>
> 
> Hi all,
> 
> These LOCALIO changes didn't land for 6.13 merge, please advise on if
> we might get these changes staged for 6.14 now-ish.

Works for me.

> 
> Trond and/or Anna, do you feel comfortable picking this series up
> (nfsd cachnges too) or would you like to see any changes before that
> is possible?

I'll go through the patches once more, but they should be fine. I will need Acked-by's for the NFSD bits from Chuck or Jeff.

Anna

> 
> Thanks,
> Mike

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Chuck Lever]

On 12/18/24 3:55 PM, Anna Schumaker wrote:
> 
> 
> On 12/18/24 12:31 PM, Mike Snitzer wrote:
>> On Fri, Nov 22, 2024 at 09:31:23PM -0500, Mike Snitzer wrote:
>>> On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
>>>> On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
>>>>> Hi,
>>>>>
>>>>> All available here:
>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
>>>>>
>>>>> Changes since v2:
>>>>> - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
>>>>>    NULL.
>>>>> - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
>>>>> - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
>>>>>    'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
>>>>>    LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
>>>>>    'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
>>>>> - added "Module Parameters" section to localio.rst
>>>>>
>>>>> All review appreciated, thanks.
>>>>> Mike
>>>>>
>>>>> Mike Snitzer (14):
>>>>>    nfs/localio: add direct IO enablement with sync and async IO support
>>>>>    nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
>>>>>    nfs_common: rename functions that invalidate LOCALIO nfs_clients
>>>>>    nfs_common: move localio_lock to new lock member of nfs_uuid_t
>>>>>    nfs: cache all open LOCALIO nfsd_file(s) in client
>>>>>    nfsd: update percpu_ref to manage references on nfsd_net
>>>>>    nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
>>>>>    nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
>>>>>    nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
>>>>>    nfs_common: track all open nfsd_files per LOCALIO nfs_client
>>>>>    nfs_common: add nfs_localio trace events
>>>>>    nfs/localio: remove redundant code and simplify LOCALIO enablement
>>>>>    nfs: probe for LOCALIO when v4 client reconnects to server
>>>>>    nfs: probe for LOCALIO when v3 client reconnects to server
>>>>>
>>>>>   Documentation/filesystems/nfs/localio.rst |  98 +++++----
>>>>>   fs/nfs/client.c                           |   6 +-
>>>>>   fs/nfs/direct.c                           |   1 +
>>>>>   fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
>>>>>   fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
>>>>>   fs/nfs/inode.c                            |   3 +
>>>>>   fs/nfs/internal.h                         |   9 +-
>>>>>   fs/nfs/localio.c                          | 232 +++++++++++++++-----
>>>>>   fs/nfs/nfs3proc.c                         |  46 +++-
>>>>>   fs/nfs/nfs4state.c                        |   1 +
>>>>>   fs/nfs/nfstrace.h                         |  32 ---
>>>>>   fs/nfs/pagelist.c                         |   5 +-
>>>>>   fs/nfs/write.c                            |   3 +-
>>>>>   fs/nfs_common/Makefile                    |   3 +-
>>>>>   fs/nfs_common/localio_trace.c             |  10 +
>>>>>   fs/nfs_common/localio_trace.h             |  56 +++++
>>>>>   fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
>>>>>   fs/nfsd/filecache.c                       |  20 +-
>>>>>   fs/nfsd/localio.c                         |   9 +-
>>>>>   fs/nfsd/netns.h                           |  12 +-
>>>>>   fs/nfsd/nfsctl.c                          |   6 +-
>>>>>   fs/nfsd/nfssvc.c                          |  40 ++--
>>>>>   include/linux/nfs_fs.h                    |  22 +-
>>>>>   include/linux/nfs_fs_sb.h                 |   3 +-
>>>>>   include/linux/nfs_xdr.h                   |   1 +
>>>>>   include/linux/nfslocalio.h                |  48 +++--
>>>>>   26 files changed, 674 insertions(+), 268 deletions(-)
>>>>>   create mode 100644 fs/nfs_common/localio_trace.c
>>>>>   create mode 100644 fs/nfs_common/localio_trace.h
>>>>>
>>>>
>>>> I went through the set and it looks mostly sane to me. The one concern
>>>> I have is that you have the client set up to start caching nfsd files
>>>> before there is a mechanism to call it and ask them to return them. You
>>>> might see some weird behavior there on a bisect, but it looks like it
>>>> all gets resolved in the end.
>>>
>>> Yeah, couldn't see a better way to atomically pivot to the new disable
>>> functionality without it needing to be a large muddled patch.
>>>
>>> Shouldn't be bad even if someone did bisect, its only the server being
>>> restarted during LOCALIO that could see issues (unlikely thing for
>>> someone to be testing for specifically with a bisect).
>>>
>>>> How do you intend for this to go in? Since most of this is client side,
>>>> will this be going in via Trond/Anna's tree?
>>>
>>> Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
>>> did have it in his testing tree, maybe your Reviewed-by helps it all
>>> land.
>>>
>>>> You can add:
>>>>
>>>> Reviewed-by: Jeff Layton <jlayton@kernel.org>
>>>
>>> Thanks,
>>> Mike
>>>
>>
>> Hi all,
>>
>> These LOCALIO changes didn't land for 6.13 merge, please advise on if
>> we might get these changes staged for 6.14 now-ish.
> 
> Works for me.
> 
>>
>> Trond and/or Anna, do you feel comfortable picking this series up
>> (nfsd cachnges too) or would you like to see any changes before that
>> is possible?
> 
> I'll go through the patches once more, but they should be fine. I will need Acked-by's for the NFSD bits from Chuck or Jeff.

Looks like Jeff gave his Reviewed-by for the series already.

I had asked for some minor changes, haven't seen them go by, but, for
the NFSD-related hunks:

Acked-by: Chuck Lever <chuck.lever@oracle.com>


-- 
Chuck Lever

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Mike Snitzer]

On Wed, Dec 18, 2024 at 04:05:23PM -0500, Chuck Lever wrote:
> On 12/18/24 3:55 PM, Anna Schumaker wrote:
> > 
> > 
> > On 12/18/24 12:31 PM, Mike Snitzer wrote:
> > > On Fri, Nov 22, 2024 at 09:31:23PM -0500, Mike Snitzer wrote:
> > > > On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
> > > > > On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
> > > > > > Hi,
> > > > > > 
> > > > > > All available here:
> > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
> > > > > > 
> > > > > > Changes since v2:
> > > > > > - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
> > > > > >    NULL.
> > > > > > - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
> > > > > > - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
> > > > > >    'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
> > > > > >    LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
> > > > > >    'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
> > > > > > - added "Module Parameters" section to localio.rst
> > > > > > 
> > > > > > All review appreciated, thanks.
> > > > > > Mike
> > > > > > 
> > > > > > Mike Snitzer (14):
> > > > > >    nfs/localio: add direct IO enablement with sync and async IO support
> > > > > >    nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
> > > > > >    nfs_common: rename functions that invalidate LOCALIO nfs_clients
> > > > > >    nfs_common: move localio_lock to new lock member of nfs_uuid_t
> > > > > >    nfs: cache all open LOCALIO nfsd_file(s) in client
> > > > > >    nfsd: update percpu_ref to manage references on nfsd_net
> > > > > >    nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
> > > > > >    nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
> > > > > >    nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
> > > > > >    nfs_common: track all open nfsd_files per LOCALIO nfs_client
> > > > > >    nfs_common: add nfs_localio trace events
> > > > > >    nfs/localio: remove redundant code and simplify LOCALIO enablement
> > > > > >    nfs: probe for LOCALIO when v4 client reconnects to server
> > > > > >    nfs: probe for LOCALIO when v3 client reconnects to server
> > > > > > 
> > > > > >   Documentation/filesystems/nfs/localio.rst |  98 +++++----
> > > > > >   fs/nfs/client.c                           |   6 +-
> > > > > >   fs/nfs/direct.c                           |   1 +
> > > > > >   fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
> > > > > >   fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
> > > > > >   fs/nfs/inode.c                            |   3 +
> > > > > >   fs/nfs/internal.h                         |   9 +-
> > > > > >   fs/nfs/localio.c                          | 232 +++++++++++++++-----
> > > > > >   fs/nfs/nfs3proc.c                         |  46 +++-
> > > > > >   fs/nfs/nfs4state.c                        |   1 +
> > > > > >   fs/nfs/nfstrace.h                         |  32 ---
> > > > > >   fs/nfs/pagelist.c                         |   5 +-
> > > > > >   fs/nfs/write.c                            |   3 +-
> > > > > >   fs/nfs_common/Makefile                    |   3 +-
> > > > > >   fs/nfs_common/localio_trace.c             |  10 +
> > > > > >   fs/nfs_common/localio_trace.h             |  56 +++++
> > > > > >   fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
> > > > > >   fs/nfsd/filecache.c                       |  20 +-
> > > > > >   fs/nfsd/localio.c                         |   9 +-
> > > > > >   fs/nfsd/netns.h                           |  12 +-
> > > > > >   fs/nfsd/nfsctl.c                          |   6 +-
> > > > > >   fs/nfsd/nfssvc.c                          |  40 ++--
> > > > > >   include/linux/nfs_fs.h                    |  22 +-
> > > > > >   include/linux/nfs_fs_sb.h                 |   3 +-
> > > > > >   include/linux/nfs_xdr.h                   |   1 +
> > > > > >   include/linux/nfslocalio.h                |  48 +++--
> > > > > >   26 files changed, 674 insertions(+), 268 deletions(-)
> > > > > >   create mode 100644 fs/nfs_common/localio_trace.c
> > > > > >   create mode 100644 fs/nfs_common/localio_trace.h
> > > > > > 
> > > > > 
> > > > > I went through the set and it looks mostly sane to me. The one concern
> > > > > I have is that you have the client set up to start caching nfsd files
> > > > > before there is a mechanism to call it and ask them to return them. You
> > > > > might see some weird behavior there on a bisect, but it looks like it
> > > > > all gets resolved in the end.
> > > > 
> > > > Yeah, couldn't see a better way to atomically pivot to the new disable
> > > > functionality without it needing to be a large muddled patch.
> > > > 
> > > > Shouldn't be bad even if someone did bisect, its only the server being
> > > > restarted during LOCALIO that could see issues (unlikely thing for
> > > > someone to be testing for specifically with a bisect).
> > > > 
> > > > > How do you intend for this to go in? Since most of this is client side,
> > > > > will this be going in via Trond/Anna's tree?
> > > > 
> > > > Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
> > > > did have it in his testing tree, maybe your Reviewed-by helps it all
> > > > land.
> > > > 
> > > > > You can add:
> > > > > 
> > > > > Reviewed-by: Jeff Layton <jlayton@kernel.org>
> > > > 
> > > > Thanks,
> > > > Mike
> > > > 
> > > 
> > > Hi all,
> > > 
> > > These LOCALIO changes didn't land for 6.13 merge, please advise on if
> > > we might get these changes staged for 6.14 now-ish.
> > 
> > Works for me.
> > 
> > > 
> > > Trond and/or Anna, do you feel comfortable picking this series up
> > > (nfsd cachnges too) or would you like to see any changes before that
> > > is possible?
> > 
> > I'll go through the patches once more, but they should be fine. I will need Acked-by's for the NFSD bits from Chuck or Jeff.
> 
> Looks like Jeff gave his Reviewed-by for the series already.
> 
> I had asked for some minor changes, haven't seen them go by,

Only thing I was aware of, and addressed in v2, was this:
https://lore.kernel.org/all/ZzNm0hekxOyAUhib@tissot.1015granger.net/

I added a module parameters section to the localio.rst and mentioned
that in v2's 0th header:
https://lore.kernel.org/r/all/20241114035952.13889-1-snitzer@kernel.org/

with:

"- updated Documentation/filesystems/nfs/localio.rst to reflect the
  percpu_ref change from nfsd_serv to nfsd_net. Also discuss O_DIRECT
  relative to LOCALIO and document the nfs module param (Chuck, I do
  think we need it, otherwise O_DIRECT regressions are possible)."

> but, for the NFSD-related hunks:
> 
> Acked-by: Chuck Lever <chuck.lever@oracle.com>

Thanks!

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Mike Snitzer]

[top-posting because of my general inquiry]

Hi Anna,

I know Trond has been quite busy, I suspect you have been too
(holidays and all too).  I just wanted to check with you on this
patchset.

Given the 6.14 merge window is fast approaching, is there anything you
need from me?

Jeff did provide his Reviewed-by, and Chuck his Acked-by.  But would
it help for me to prepare a v4 that explicitly adds their tags
accordingly?

There is also this LOCALIO error path fix that should go upstream and
be marked for stable@:
https://lore.kernel.org/linux-nfs/20241227201356.3074-1-snitzer@kernel.org/

I could put that fix in the front of a v4 resubmission.  I'm also
perfectly fine to stand-down and let you review and apply if/when you
have time.. the patches haven't changed at all, but happy to sweep
through and do the v4 if it helps.

Thanks,
Mike


On Wed, Dec 18, 2024 at 04:19:42PM -0500, Mike Snitzer wrote:
> On Wed, Dec 18, 2024 at 04:05:23PM -0500, Chuck Lever wrote:
> > On 12/18/24 3:55 PM, Anna Schumaker wrote:
> > > 
> > > 
> > > On 12/18/24 12:31 PM, Mike Snitzer wrote:
> > > > On Fri, Nov 22, 2024 at 09:31:23PM -0500, Mike Snitzer wrote:
> > > > > On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
> > > > > > On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
> > > > > > > Hi,
> > > > > > > 
> > > > > > > All available here:
> > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
> > > > > > > 
> > > > > > > Changes since v2:
> > > > > > > - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
> > > > > > >    NULL.
> > > > > > > - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
> > > > > > > - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
> > > > > > >    'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
> > > > > > >    LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
> > > > > > >    'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
> > > > > > > - added "Module Parameters" section to localio.rst
> > > > > > > 
> > > > > > > All review appreciated, thanks.
> > > > > > > Mike
> > > > > > > 
> > > > > > > Mike Snitzer (14):
> > > > > > >    nfs/localio: add direct IO enablement with sync and async IO support
> > > > > > >    nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
> > > > > > >    nfs_common: rename functions that invalidate LOCALIO nfs_clients
> > > > > > >    nfs_common: move localio_lock to new lock member of nfs_uuid_t
> > > > > > >    nfs: cache all open LOCALIO nfsd_file(s) in client
> > > > > > >    nfsd: update percpu_ref to manage references on nfsd_net
> > > > > > >    nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
> > > > > > >    nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
> > > > > > >    nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
> > > > > > >    nfs_common: track all open nfsd_files per LOCALIO nfs_client
> > > > > > >    nfs_common: add nfs_localio trace events
> > > > > > >    nfs/localio: remove redundant code and simplify LOCALIO enablement
> > > > > > >    nfs: probe for LOCALIO when v4 client reconnects to server
> > > > > > >    nfs: probe for LOCALIO when v3 client reconnects to server
> > > > > > > 
> > > > > > >   Documentation/filesystems/nfs/localio.rst |  98 +++++----
> > > > > > >   fs/nfs/client.c                           |   6 +-
> > > > > > >   fs/nfs/direct.c                           |   1 +
> > > > > > >   fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
> > > > > > >   fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
> > > > > > >   fs/nfs/inode.c                            |   3 +
> > > > > > >   fs/nfs/internal.h                         |   9 +-
> > > > > > >   fs/nfs/localio.c                          | 232 +++++++++++++++-----
> > > > > > >   fs/nfs/nfs3proc.c                         |  46 +++-
> > > > > > >   fs/nfs/nfs4state.c                        |   1 +
> > > > > > >   fs/nfs/nfstrace.h                         |  32 ---
> > > > > > >   fs/nfs/pagelist.c                         |   5 +-
> > > > > > >   fs/nfs/write.c                            |   3 +-
> > > > > > >   fs/nfs_common/Makefile                    |   3 +-
> > > > > > >   fs/nfs_common/localio_trace.c             |  10 +
> > > > > > >   fs/nfs_common/localio_trace.h             |  56 +++++
> > > > > > >   fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
> > > > > > >   fs/nfsd/filecache.c                       |  20 +-
> > > > > > >   fs/nfsd/localio.c                         |   9 +-
> > > > > > >   fs/nfsd/netns.h                           |  12 +-
> > > > > > >   fs/nfsd/nfsctl.c                          |   6 +-
> > > > > > >   fs/nfsd/nfssvc.c                          |  40 ++--
> > > > > > >   include/linux/nfs_fs.h                    |  22 +-
> > > > > > >   include/linux/nfs_fs_sb.h                 |   3 +-
> > > > > > >   include/linux/nfs_xdr.h                   |   1 +
> > > > > > >   include/linux/nfslocalio.h                |  48 +++--
> > > > > > >   26 files changed, 674 insertions(+), 268 deletions(-)
> > > > > > >   create mode 100644 fs/nfs_common/localio_trace.c
> > > > > > >   create mode 100644 fs/nfs_common/localio_trace.h
> > > > > > > 
> > > > > > 
> > > > > > I went through the set and it looks mostly sane to me. The one concern
> > > > > > I have is that you have the client set up to start caching nfsd files
> > > > > > before there is a mechanism to call it and ask them to return them. You
> > > > > > might see some weird behavior there on a bisect, but it looks like it
> > > > > > all gets resolved in the end.
> > > > > 
> > > > > Yeah, couldn't see a better way to atomically pivot to the new disable
> > > > > functionality without it needing to be a large muddled patch.
> > > > > 
> > > > > Shouldn't be bad even if someone did bisect, its only the server being
> > > > > restarted during LOCALIO that could see issues (unlikely thing for
> > > > > someone to be testing for specifically with a bisect).
> > > > > 
> > > > > > How do you intend for this to go in? Since most of this is client side,
> > > > > > will this be going in via Trond/Anna's tree?
> > > > > 
> > > > > Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
> > > > > did have it in his testing tree, maybe your Reviewed-by helps it all
> > > > > land.
> > > > > 
> > > > > > You can add:
> > > > > > 
> > > > > > Reviewed-by: Jeff Layton <jlayton@kernel.org>
> > > > > 
> > > > > Thanks,
> > > > > Mike
> > > > > 
> > > > 
> > > > Hi all,
> > > > 
> > > > These LOCALIO changes didn't land for 6.13 merge, please advise on if
> > > > we might get these changes staged for 6.14 now-ish.
> > > 
> > > Works for me.
> > > 
> > > > 
> > > > Trond and/or Anna, do you feel comfortable picking this series up
> > > > (nfsd cachnges too) or would you like to see any changes before that
> > > > is possible?
> > > 
> > > I'll go through the patches once more, but they should be fine. I will need Acked-by's for the NFSD bits from Chuck or Jeff.
> > 
> > Looks like Jeff gave his Reviewed-by for the series already.
> > 
> > I had asked for some minor changes, haven't seen them go by,
> 
> Only thing I was aware of, and addressed in v2, was this:
> https://lore.kernel.org/all/ZzNm0hekxOyAUhib@tissot.1015granger.net/
> 
> I added a module parameters section to the localio.rst and mentioned
> that in v2's 0th header:
> https://lore.kernel.org/r/all/20241114035952.13889-1-snitzer@kernel.org/
> 
> with:
> 
> "- updated Documentation/filesystems/nfs/localio.rst to reflect the
>   percpu_ref change from nfsd_serv to nfsd_net. Also discuss O_DIRECT
>   relative to LOCALIO and document the nfs module param (Chuck, I do
>   think we need it, otherwise O_DIRECT regressions are possible)."
> 
> > but, for the NFSD-related hunks:
> > 
> > Acked-by: Chuck Lever <chuck.lever@oracle.com>
> 
> Thanks!
> 

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Anna Schumaker]

Hi Mike,

On 1/8/25 11:05 AM, Mike Snitzer wrote:
> [top-posting because of my general inquiry]
> 
> Hi Anna,
> 
> I know Trond has been quite busy, I suspect you have been too
> (holidays and all too).  I just wanted to check with you on this
> patchset.
> 
> Given the 6.14 merge window is fast approaching, is there anything you
> need from me?
> 
> Jeff did provide his Reviewed-by, and Chuck his Acked-by.  But would
> it help for me to prepare a v4 that explicitly adds their tags
> accordingly?

Thanks for checking in! I don't think I need anything from you at this time. I just pushed out a linux-next branch including these patches and your additional bugfix from the other week, so everything should be covered. If you notice anything missing, do let me know!

Anna

> 
> There is also this LOCALIO error path fix that should go upstream and
> be marked for stable@:
> https://lore.kernel.org/linux-nfs/20241227201356.3074-1-snitzer@kernel.org/
> 
> I could put that fix in the front of a v4 resubmission.  I'm also
> perfectly fine to stand-down and let you review and apply if/when you
> have time.. the patches haven't changed at all, but happy to sweep
> through and do the v4 if it helps.
> 
> Thanks,
> Mike
> 
> 
> On Wed, Dec 18, 2024 at 04:19:42PM -0500, Mike Snitzer wrote:
>> On Wed, Dec 18, 2024 at 04:05:23PM -0500, Chuck Lever wrote:
>>> On 12/18/24 3:55 PM, Anna Schumaker wrote:
>>>>
>>>>
>>>> On 12/18/24 12:31 PM, Mike Snitzer wrote:
>>>>> On Fri, Nov 22, 2024 at 09:31:23PM -0500, Mike Snitzer wrote:
>>>>>> On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
>>>>>>> On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> All available here:
>>>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
>>>>>>>>
>>>>>>>> Changes since v2:
>>>>>>>> - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
>>>>>>>>    NULL.
>>>>>>>> - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
>>>>>>>> - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
>>>>>>>>    'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
>>>>>>>>    LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
>>>>>>>>    'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
>>>>>>>> - added "Module Parameters" section to localio.rst
>>>>>>>>
>>>>>>>> All review appreciated, thanks.
>>>>>>>> Mike
>>>>>>>>
>>>>>>>> Mike Snitzer (14):
>>>>>>>>    nfs/localio: add direct IO enablement with sync and async IO support
>>>>>>>>    nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
>>>>>>>>    nfs_common: rename functions that invalidate LOCALIO nfs_clients
>>>>>>>>    nfs_common: move localio_lock to new lock member of nfs_uuid_t
>>>>>>>>    nfs: cache all open LOCALIO nfsd_file(s) in client
>>>>>>>>    nfsd: update percpu_ref to manage references on nfsd_net
>>>>>>>>    nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
>>>>>>>>    nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
>>>>>>>>    nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
>>>>>>>>    nfs_common: track all open nfsd_files per LOCALIO nfs_client
>>>>>>>>    nfs_common: add nfs_localio trace events
>>>>>>>>    nfs/localio: remove redundant code and simplify LOCALIO enablement
>>>>>>>>    nfs: probe for LOCALIO when v4 client reconnects to server
>>>>>>>>    nfs: probe for LOCALIO when v3 client reconnects to server
>>>>>>>>
>>>>>>>>   Documentation/filesystems/nfs/localio.rst |  98 +++++----
>>>>>>>>   fs/nfs/client.c                           |   6 +-
>>>>>>>>   fs/nfs/direct.c                           |   1 +
>>>>>>>>   fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
>>>>>>>>   fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
>>>>>>>>   fs/nfs/inode.c                            |   3 +
>>>>>>>>   fs/nfs/internal.h                         |   9 +-
>>>>>>>>   fs/nfs/localio.c                          | 232 +++++++++++++++-----
>>>>>>>>   fs/nfs/nfs3proc.c                         |  46 +++-
>>>>>>>>   fs/nfs/nfs4state.c                        |   1 +
>>>>>>>>   fs/nfs/nfstrace.h                         |  32 ---
>>>>>>>>   fs/nfs/pagelist.c                         |   5 +-
>>>>>>>>   fs/nfs/write.c                            |   3 +-
>>>>>>>>   fs/nfs_common/Makefile                    |   3 +-
>>>>>>>>   fs/nfs_common/localio_trace.c             |  10 +
>>>>>>>>   fs/nfs_common/localio_trace.h             |  56 +++++
>>>>>>>>   fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
>>>>>>>>   fs/nfsd/filecache.c                       |  20 +-
>>>>>>>>   fs/nfsd/localio.c                         |   9 +-
>>>>>>>>   fs/nfsd/netns.h                           |  12 +-
>>>>>>>>   fs/nfsd/nfsctl.c                          |   6 +-
>>>>>>>>   fs/nfsd/nfssvc.c                          |  40 ++--
>>>>>>>>   include/linux/nfs_fs.h                    |  22 +-
>>>>>>>>   include/linux/nfs_fs_sb.h                 |   3 +-
>>>>>>>>   include/linux/nfs_xdr.h                   |   1 +
>>>>>>>>   include/linux/nfslocalio.h                |  48 +++--
>>>>>>>>   26 files changed, 674 insertions(+), 268 deletions(-)
>>>>>>>>   create mode 100644 fs/nfs_common/localio_trace.c
>>>>>>>>   create mode 100644 fs/nfs_common/localio_trace.h
>>>>>>>>
>>>>>>>
>>>>>>> I went through the set and it looks mostly sane to me. The one concern
>>>>>>> I have is that you have the client set up to start caching nfsd files
>>>>>>> before there is a mechanism to call it and ask them to return them. You
>>>>>>> might see some weird behavior there on a bisect, but it looks like it
>>>>>>> all gets resolved in the end.
>>>>>>
>>>>>> Yeah, couldn't see a better way to atomically pivot to the new disable
>>>>>> functionality without it needing to be a large muddled patch.
>>>>>>
>>>>>> Shouldn't be bad even if someone did bisect, its only the server being
>>>>>> restarted during LOCALIO that could see issues (unlikely thing for
>>>>>> someone to be testing for specifically with a bisect).
>>>>>>
>>>>>>> How do you intend for this to go in? Since most of this is client side,
>>>>>>> will this be going in via Trond/Anna's tree?
>>>>>>
>>>>>> Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
>>>>>> did have it in his testing tree, maybe your Reviewed-by helps it all
>>>>>> land.
>>>>>>
>>>>>>> You can add:
>>>>>>>
>>>>>>> Reviewed-by: Jeff Layton <jlayton@kernel.org>
>>>>>>
>>>>>> Thanks,
>>>>>> Mike
>>>>>>
>>>>>
>>>>> Hi all,
>>>>>
>>>>> These LOCALIO changes didn't land for 6.13 merge, please advise on if
>>>>> we might get these changes staged for 6.14 now-ish.
>>>>
>>>> Works for me.
>>>>
>>>>>
>>>>> Trond and/or Anna, do you feel comfortable picking this series up
>>>>> (nfsd cachnges too) or would you like to see any changes before that
>>>>> is possible?
>>>>
>>>> I'll go through the patches once more, but they should be fine. I will need Acked-by's for the NFSD bits from Chuck or Jeff.
>>>
>>> Looks like Jeff gave his Reviewed-by for the series already.
>>>
>>> I had asked for some minor changes, haven't seen them go by,
>>
>> Only thing I was aware of, and addressed in v2, was this:
>> https://lore.kernel.org/all/ZzNm0hekxOyAUhib@tissot.1015granger.net/
>>
>> I added a module parameters section to the localio.rst and mentioned
>> that in v2's 0th header:
>> https://lore.kernel.org/r/all/20241114035952.13889-1-snitzer@kernel.org/
>>
>> with:
>>
>> "- updated Documentation/filesystems/nfs/localio.rst to reflect the
>>   percpu_ref change from nfsd_serv to nfsd_net. Also discuss O_DIRECT
>>   relative to LOCALIO and document the nfs module param (Chuck, I do
>>   think we need it, otherwise O_DIRECT regressions are possible)."
>>
>>> but, for the NFSD-related hunks:
>>>
>>> Acked-by: Chuck Lever <chuck.lever@oracle.com>
>>
>> Thanks!
>>
> 

[PATCH v2] nfs: fix incorrect error handling in LOCALIO (was: Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO)

[Mike Snitzer]

On Wed, Jan 08, 2025 at 03:56:27PM -0500, Anna Schumaker wrote:
> Hi Mike,
> 
> On 1/8/25 11:05 AM, Mike Snitzer wrote:
> > [top-posting because of my general inquiry]
> > 
> > Hi Anna,
> > 
> > I know Trond has been quite busy, I suspect you have been too
> > (holidays and all too).  I just wanted to check with you on this
> > patchset.
> > 
> > Given the 6.14 merge window is fast approaching, is there anything you
> > need from me?
> > 
> > Jeff did provide his Reviewed-by, and Chuck his Acked-by.  But would
> > it help for me to prepare a v4 that explicitly adds their tags
> > accordingly?
> 
> Thanks for checking in! I don't think I need anything from you at
> this time. I just pushed out a linux-next branch including these
> patches and your additional bugfix from the other week, so everything
> should be covered. If you notice anything missing, do let me know!

Thanks!  And of course I sent my previous mail _just_ before you
pushed your linux-next changes out. ;)

I do have the following v2 for the LOCALIO bugfix, commit 17da35c54142
("nfs: fix incorrect error handling in LOCALIO") in your linux-next
tree.  Once you've had a chance to look, would it be possible for you
to replace the original fix and forcibly rebase with this v2 instead?

Trond reviewed the first patch and noted that for LOCALIO's purposes
it results in some bad conversions from errno to NFSv4 status
(e.g. -EAGAIN to NFS4ERR_LOCKED and -ENODATA to NFS4ERR_NOXATTR).  I
cross-referenced the long-standing code that Hammerspace used for this
and this v2 reflects the errno to NFS v4 status mappings LOCALIO
needs:


From: Mike Snitzer <snitzer@kernel.org>
Subject: [PATCH v2] nfs: fix incorrect error handling in LOCALIO

nfs4_stat_to_errno() expects a NFSv4 error code as an argument and
returns a POSIX errno.

The problem is LOCALIO is passing nfs4_stat_to_errno() the POSIX errno
return values from filp->f_op->read_iter(), filp->f_op->write_iter()
and vfs_fsync_range().

So the POSIX errno that nfs_local_pgio_done() and
nfs_local_commit_done() are passing to nfs4_stat_to_errno() are
failing to match any NFSv4 error code, which results in
nfs4_stat_to_errno() defaulting to returning -EREMOTEIO. This causes
assertions in upper layers due to -EREMOTEIO not being a valid NFSv4
error code.

Fix this by updating nfs_local_pgio_done() and nfs_local_commit_done()
to use the new nfs_localio_errno_to_nfs4_stat() to map a POSIX errno
to an NFSv4 error code.

Care was taken to factor out nfs4_errtbl_common[] to avoid duplicating
the same NFS error to errno table. nfs4_errtbl_common[] is checked
first by both nfs4_stat_to_errno and nfs_localio_errno_to_nfs4_stat
before they check their own more specialized tables (nfs4_errtbl[] and
nfs4_errtbl_localio[] respectively).

While auditing the associated error mapping tables, the (ab)use of -1
for the last table entry was removed in favor of using ARRAY_SIZE to
iterate the nfs_errtbl[] and nfs4_errtbl[]. And 'errno_NFSERR_IO' was
removed because it caused needless obfuscation.

Fixes: 70ba381e1a431 ("nfs: add LOCALIO support")
Reported-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
 fs/nfs/localio.c           |  4 +-
 fs/nfs_common/common.c     | 89 +++++++++++++++++++++++++++++++++-----
 include/linux/nfs_common.h |  3 +-
 3 files changed, 82 insertions(+), 14 deletions(-)

diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 1eee5aac2884..5c21caeae075 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -388,7 +388,7 @@ nfs_local_pgio_done(struct nfs_pgio_header *hdr, long status)
 		hdr->res.op_status = NFS4_OK;
 		hdr->task.tk_status = 0;
 	} else {
-		hdr->res.op_status = nfs4_stat_to_errno(status);
+		hdr->res.op_status = nfs_localio_errno_to_nfs4_stat(status);
 		hdr->task.tk_status = status;
 	}
 }
@@ -786,7 +786,7 @@ nfs_local_commit_done(struct nfs_commit_data *data, int status)
 		data->task.tk_status = 0;
 	} else {
 		nfs_reset_boot_verifier(data->inode);
-		data->res.op_status = nfs4_stat_to_errno(status);
+		data->res.op_status = nfs_localio_errno_to_nfs4_stat(status);
 		data->task.tk_status = status;
 	}
 }
diff --git a/fs/nfs_common/common.c b/fs/nfs_common/common.c
index 34a115176f97..af09aed09fd2 100644
--- a/fs/nfs_common/common.c
+++ b/fs/nfs_common/common.c
@@ -15,7 +15,7 @@ static const struct {
 	{ NFS_OK,		0		},
 	{ NFSERR_PERM,		-EPERM		},
 	{ NFSERR_NOENT,		-ENOENT		},
-	{ NFSERR_IO,		-errno_NFSERR_IO},
+	{ NFSERR_IO,		-EIO		},
 	{ NFSERR_NXIO,		-ENXIO		},
 /*	{ NFSERR_EAGAIN,	-EAGAIN		}, */
 	{ NFSERR_ACCES,		-EACCES		},
@@ -45,7 +45,6 @@ static const struct {
 	{ NFSERR_SERVERFAULT,	-EREMOTEIO	},
 	{ NFSERR_BADTYPE,	-EBADTYPE	},
 	{ NFSERR_JUKEBOX,	-EJUKEBOX	},
-	{ -1,			-EIO		}
 };
 
 /**
@@ -59,26 +58,29 @@ int nfs_stat_to_errno(enum nfs_stat status)
 {
 	int i;
 
-	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
+	for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
 		if (nfs_errtbl[i].stat == (int)status)
 			return nfs_errtbl[i].errno;
 	}
-	return nfs_errtbl[i].errno;
+	return -EIO;
 }
 EXPORT_SYMBOL_GPL(nfs_stat_to_errno);
 
 /*
  * We need to translate between nfs v4 status return values and
  * the local errno values which may not be the same.
+ *
+ * nfs4_errtbl_common[] is used before more specialized mappings
+ * available in nfs4_errtbl[] or nfs4_errtbl_localio[].
  */
 static const struct {
 	int stat;
 	int errno;
-} nfs4_errtbl[] = {
+} nfs4_errtbl_common[] = {
 	{ NFS4_OK,		0		},
 	{ NFS4ERR_PERM,		-EPERM		},
 	{ NFS4ERR_NOENT,	-ENOENT		},
-	{ NFS4ERR_IO,		-errno_NFSERR_IO},
+	{ NFS4ERR_IO,		-EIO		},
 	{ NFS4ERR_NXIO,		-ENXIO		},
 	{ NFS4ERR_ACCESS,	-EACCES		},
 	{ NFS4ERR_EXIST,	-EEXIST		},
@@ -98,15 +100,20 @@ static const struct {
 	{ NFS4ERR_BAD_COOKIE,	-EBADCOOKIE	},
 	{ NFS4ERR_NOTSUPP,	-ENOTSUPP	},
 	{ NFS4ERR_TOOSMALL,	-ETOOSMALL	},
-	{ NFS4ERR_SERVERFAULT,	-EREMOTEIO	},
 	{ NFS4ERR_BADTYPE,	-EBADTYPE	},
-	{ NFS4ERR_LOCKED,	-EAGAIN		},
 	{ NFS4ERR_SYMLINK,	-ELOOP		},
-	{ NFS4ERR_OP_ILLEGAL,	-EOPNOTSUPP	},
 	{ NFS4ERR_DEADLOCK,	-EDEADLK	},
+};
+
+static const struct {
+	int stat;
+	int errno;
+} nfs4_errtbl[] = {
+	{ NFS4ERR_SERVERFAULT,	-EREMOTEIO	},
+	{ NFS4ERR_LOCKED,	-EAGAIN		},
+	{ NFS4ERR_OP_ILLEGAL,	-EOPNOTSUPP	},
 	{ NFS4ERR_NOXATTR,	-ENODATA	},
 	{ NFS4ERR_XATTR2BIG,	-E2BIG		},
-	{ -1,			-EIO		}
 };
 
 /*
@@ -116,7 +123,14 @@ static const struct {
 int nfs4_stat_to_errno(int stat)
 {
 	int i;
-	for (i = 0; nfs4_errtbl[i].stat != -1; i++) {
+
+	/* First check nfs4_errtbl_common */
+	for (i = 0; i < ARRAY_SIZE(nfs4_errtbl_common); i++) {
+		if (nfs4_errtbl_common[i].stat == stat)
+			return nfs4_errtbl_common[i].errno;
+	}
+	/* Then check nfs4_errtbl */
+	for (i = 0; i < ARRAY_SIZE(nfs4_errtbl); i++) {
 		if (nfs4_errtbl[i].stat == stat)
 			return nfs4_errtbl[i].errno;
 	}
@@ -132,3 +146,56 @@ int nfs4_stat_to_errno(int stat)
 	return -stat;
 }
 EXPORT_SYMBOL_GPL(nfs4_stat_to_errno);
+
+/*
+ * This table is useful for conversion from local errno to NFS error.
+ * It provides more logically correct mappings for use with LOCALIO
+ * (which is focused on converting from errno to NFS status).
+ */
+static const struct {
+	int stat;
+	int errno;
+} nfs4_errtbl_localio[] = {
+	/* Map errors differently than nfs4_errtbl */
+	{ NFS4ERR_IO,		-EREMOTEIO	},
+	{ NFS4ERR_DELAY,	-EAGAIN		},
+	{ NFS4ERR_FBIG,		-E2BIG		},
+	/* Map errors not handled by nfs4_errtbl */
+	{ NFS4ERR_STALE,	-EBADF		},
+	{ NFS4ERR_STALE,	-EOPENSTALE	},
+	{ NFS4ERR_DELAY,	-ETIMEDOUT	},
+	{ NFS4ERR_DELAY,	-ERESTARTSYS	},
+	{ NFS4ERR_DELAY,	-ENOMEM		},
+	{ NFS4ERR_IO,		-ETXTBSY	},
+	{ NFS4ERR_IO,		-EBUSY		},
+	{ NFS4ERR_SERVERFAULT,	-ESERVERFAULT	},
+	{ NFS4ERR_SERVERFAULT,	-ENFILE		},
+	{ NFS4ERR_IO,		-EUCLEAN	},
+	{ NFS4ERR_PERM,		-ENOKEY		},
+};
+
+/*
+ * Convert an errno to an NFS error code for LOCALIO.
+ */
+__u32 nfs_localio_errno_to_nfs4_stat(int errno)
+{
+	int i;
+
+	/* First check nfs4_errtbl_common */
+	for (i = 0; i < ARRAY_SIZE(nfs4_errtbl_common); i++) {
+		if (nfs4_errtbl_common[i].errno == errno)
+			return nfs4_errtbl_common[i].stat;
+	}
+	/* Then check nfs4_errtbl_localio */
+	for (i = 0; i < ARRAY_SIZE(nfs4_errtbl_localio); i++) {
+		if (nfs4_errtbl_localio[i].errno == errno)
+			return nfs4_errtbl_localio[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;
+}
+EXPORT_SYMBOL_GPL(nfs_localio_errno_to_nfs4_stat);
diff --git a/include/linux/nfs_common.h b/include/linux/nfs_common.h
index 5fc02df88252..a541c3a02887 100644
--- a/include/linux/nfs_common.h
+++ b/include/linux/nfs_common.h
@@ -9,9 +9,10 @@
 #include <uapi/linux/nfs.h>
 
 /* Mapping from NFS error code to "errno" error code. */
-#define errno_NFSERR_IO EIO
 
 int nfs_stat_to_errno(enum nfs_stat status);
 int nfs4_stat_to_errno(int stat);
 
+__u32 nfs_localio_errno_to_nfs4_stat(int errno);
+
 #endif /* _LINUX_NFS_COMMON_H */
-- 
2.44.0

Re: [for-6.13 PATCH v3 00/14] nfs/nfsd: improvements for LOCALIO

[Mike Snitzer]

On Wed, Dec 18, 2024 at 03:55:16PM -0500, Anna Schumaker wrote:
> 
> 
> On 12/18/24 12:31 PM, Mike Snitzer wrote:
> > On Fri, Nov 22, 2024 at 09:31:23PM -0500, Mike Snitzer wrote:
> >> On Fri, Nov 22, 2024 at 12:26:39PM -0500, Jeff Layton wrote:
> >>> On Fri, 2024-11-15 at 20:40 -0500, Mike Snitzer wrote:
> >>>> Hi,
> >>>>
> >>>> All available here:
> >>>> https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git/log/?h=nfs-localio-for-next
> >>>>
> >>>> Changes since v2:
> >>>> - switched from rcu_assign_pointer to RCU_INIT_POINTER when setting to
> >>>>   NULL.
> >>>> - removed some unnecessary #if IS_ENABLED(CONFIG_NFS_LOCALIO)
> >>>> - revised the NFS v3 probe patch to use a new nfsv3.ko modparam
> >>>>   'nfs3_localio_probe_throttle' to control if NFSv3 will probe for
> >>>>   LOCALIO. Avoids use of NFS_CS_LOCAL_IO and will probe every
> >>>>   'nfs3_localio_probe_throttle' IO requests (defaults to 0, disabled).
> >>>> - added "Module Parameters" section to localio.rst
> >>>>
> >>>> All review appreciated, thanks.
> >>>> Mike
> >>>>
> >>>> Mike Snitzer (14):
> >>>>   nfs/localio: add direct IO enablement with sync and async IO support
> >>>>   nfsd: add nfsd_file_{get,put} to 'nfs_to' nfsd_localio_operations
> >>>>   nfs_common: rename functions that invalidate LOCALIO nfs_clients
> >>>>   nfs_common: move localio_lock to new lock member of nfs_uuid_t
> >>>>   nfs: cache all open LOCALIO nfsd_file(s) in client
> >>>>   nfsd: update percpu_ref to manage references on nfsd_net
> >>>>   nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_
> >>>>   nfsd: nfsd_file_acquire_local no longer returns GC'd nfsd_file
> >>>>   nfs_common: rename nfslocalio nfs_uuid_lock to nfs_uuids_lock
> >>>>   nfs_common: track all open nfsd_files per LOCALIO nfs_client
> >>>>   nfs_common: add nfs_localio trace events
> >>>>   nfs/localio: remove redundant code and simplify LOCALIO enablement
> >>>>   nfs: probe for LOCALIO when v4 client reconnects to server
> >>>>   nfs: probe for LOCALIO when v3 client reconnects to server
> >>>>
> >>>>  Documentation/filesystems/nfs/localio.rst |  98 +++++----
> >>>>  fs/nfs/client.c                           |   6 +-
> >>>>  fs/nfs/direct.c                           |   1 +
> >>>>  fs/nfs/flexfilelayout/flexfilelayout.c    |  25 +--
> >>>>  fs/nfs/flexfilelayout/flexfilelayout.h    |   1 +
> >>>>  fs/nfs/inode.c                            |   3 +
> >>>>  fs/nfs/internal.h                         |   9 +-
> >>>>  fs/nfs/localio.c                          | 232 +++++++++++++++-----
> >>>>  fs/nfs/nfs3proc.c                         |  46 +++-
> >>>>  fs/nfs/nfs4state.c                        |   1 +
> >>>>  fs/nfs/nfstrace.h                         |  32 ---
> >>>>  fs/nfs/pagelist.c                         |   5 +-
> >>>>  fs/nfs/write.c                            |   3 +-
> >>>>  fs/nfs_common/Makefile                    |   3 +-
> >>>>  fs/nfs_common/localio_trace.c             |  10 +
> >>>>  fs/nfs_common/localio_trace.h             |  56 +++++
> >>>>  fs/nfs_common/nfslocalio.c                | 250 +++++++++++++++++-----
> >>>>  fs/nfsd/filecache.c                       |  20 +-
> >>>>  fs/nfsd/localio.c                         |   9 +-
> >>>>  fs/nfsd/netns.h                           |  12 +-
> >>>>  fs/nfsd/nfsctl.c                          |   6 +-
> >>>>  fs/nfsd/nfssvc.c                          |  40 ++--
> >>>>  include/linux/nfs_fs.h                    |  22 +-
> >>>>  include/linux/nfs_fs_sb.h                 |   3 +-
> >>>>  include/linux/nfs_xdr.h                   |   1 +
> >>>>  include/linux/nfslocalio.h                |  48 +++--
> >>>>  26 files changed, 674 insertions(+), 268 deletions(-)
> >>>>  create mode 100644 fs/nfs_common/localio_trace.c
> >>>>  create mode 100644 fs/nfs_common/localio_trace.h
> >>>>
> >>>
> >>> I went through the set and it looks mostly sane to me. The one concern
> >>> I have is that you have the client set up to start caching nfsd files
> >>> before there is a mechanism to call it and ask them to return them. You
> >>> might see some weird behavior there on a bisect, but it looks like it
> >>> all gets resolved in the end.
> >>
> >> Yeah, couldn't see a better way to atomically pivot to the new disable
> >> functionality without it needing to be a large muddled patch.
> >>
> >> Shouldn't be bad even if someone did bisect, its only the server being
> >> restarted during LOCALIO that could see issues (unlikely thing for
> >> someone to be testing for specifically with a bisect).
> >>
> >>> How do you intend for this to go in? Since most of this is client side,
> >>> will this be going in via Trond/Anna's tree?
> >>
> >> Yes, likely easiest to have it go through Trond/Anna's tree.  Trond
> >> did have it in his testing tree, maybe your Reviewed-by helps it all
> >> land.
> >>
> >>> You can add:
> >>>
> >>> Reviewed-by: Jeff Layton <jlayton@kernel.org>
> >>
> >> Thanks,
> >> Mike
> >>
> > 
> > Hi all,
> > 
> > These LOCALIO changes didn't land for 6.13 merge, please advise on if
> > we might get these changes staged for 6.14 now-ish.
> 
> Works for me.
> 
> > 
> > Trond and/or Anna, do you feel comfortable picking this series up
> > (nfsd cachnges too) or would you like to see any changes before that
> > is possible?
> 
> I'll go through the patches once more, but they should be fine. I will need Acked-by's for the NFSD bits from Chuck or Jeff.

OK, Jeff did already provide his Reviewed-by for the entire set (still
visible in the exchange I quoted above).

Thanks,
Mike