libnetfs: Support for file record locking

2019-03-04  Svante Signell <svante.signell@gmail.com>

	* file-lock.c: Make flock work regardless of the
          mode in which the file was opened.

2019-02-12  Svante Signell <svante.signell@gmail.com>

	* file-lock.c: Comment out "Make flock work without R or W mode"

2019-02-01  Svante Signell <svante.signell@gmail.com>

       * Update copyright years.
       * file-record-lock.c(netfs_S_file_record_lock):
         Don't set rendezvous to MACH_PORT_NULL.

2017-01-05  Svante Signell <svante.signell@gmail.com>

	* Update copyright years and headers.
	* dir-lookup.c(netfs_S_dir_lookup): Call fshelp_rlock_tweak()
          with new last argument rendezvous = MACH_PORT_NULL.
	* file-lock.c(netfs_S_file_lock): Likewise.
	* file-record-lock.c(netfs_S_file_record_lock): Likewise.
	(netfs_S_file_record_lock): Add new argument mach_port_t rendezvous.

2016-05-23  Svante Signell <svante.signell@gmail.com>

	* netfs.h (struct peropen): Change the type of rlock_status from
	an int to a struct rlock_peropen.
	(struct node): Change the type of userbox from a struct lock_box
	to a struct rlock_box.
	* dir-lookup.c (netfs_S_dir_lookup): Use fshelp_rlock_tweak.
	* file-lock-stat.c (netfs_S_file_lock_stat): Total rewrite
	around the new record locking functions.
	* file-lock.c (netfs_S_file_lock): Likewise.
	* file-record-lock.c (netfs_S_file_record_lock): Likewise.
	* make-node.c (netfs_make_node): Initialize userbox with
	fshelp_rlock_init.
	* make-peropen.c (netfs_make_peropen): Initialize lock_status
	using fshelp_rlock_po_init.
	(netfs_make_peropen): Add a comment that po->refcnt starts at zero.
	* relese-peropen.c (netfs_release_peropen): Release lock_status
	using fshelp_rlock_drop_peropen.

2001-04-11  Neal H Walfield  <neal@cs.uml.edu>

	* file-record-lock.c: New file.  Implement
	netfs_S_file_record_lock.
	* Makefile (SRCS): Add file-record-lock.c

9 files changed, 167 insertions, 60 deletions

diff --git a/libnetfs/Makefile b/libnetfs/Makefile
index de06816e..0d4205d5 100644
--- a/libnetfs/Makefile
+++ b/libnetfs/Makefile
@@ -1,5 +1,5 @@
-#   Copyright (C) 1995, 1996, 1997, 1999, 2001, 2002, 2008, 2012 Free Software
-#   Foundation
+#   Copyright (C) 1995-1997, 1999, 2001-2002, 2008, 2012, 2016-2019
+#   Free Software Foundation
 #
 #   Written by Michael I. Bushnell.
 #
@@ -14,10 +14,9 @@
 #   WITHOUT ANY WARRANTY; without even the implied warranty of
 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 #   General Public License for more details.
-#
+
 #   You should have received a copy of the GNU General Public License
-#   along with this program; if not, write to the Free Software
-#   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+#   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.
 
 dir := libnetfs
 makemode := library
@@ -34,7 +33,8 @@ FSSRCS= dir-link.c dir-lookup.c dir-mkdir.c dir-mkfile.c \
 	file-get-translator.c file-getcontrol.c file-getlinknode.c \
 	file-lock-stat.c file-lock.c file-set-size.c \
 	file-set-translator.c file-statfs.c file-sync.c file-syncfs.c \
-	file-utimes.c file-reparent.c fsstubs.c	file-get-transcntl.c
+	file-utimes.c file-record-lock.c file-reparent.c fsstubs.c \
+	file-get-transcntl.c
 
 IOSRCS=	io-read.c io-readable.c io-seek.c io-write.c io-stat.c io-async.c     \
 	io-set-all-openmodes.c io-get-openmodes.c io-set-some-openmodes.c     \
diff --git a/libnetfs/dir-lookup.c b/libnetfs/dir-lookup.c
index a135917f..23adeb33 100644
--- a/libnetfs/dir-lookup.c
+++ b/libnetfs/dir-lookup.c
@@ -1,6 +1,5 @@
 /*
-   Copyright (C) 1995,96,97,98,99,2000,01,02,13,14
-     Free Software Foundation, Inc.
+   Copyright (C) 1995-2002, 2013-2019 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -16,8 +15,7 @@
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <fcntl.h>
 #include <assert-backtrace.h>
@@ -438,24 +436,50 @@ netfs_S_dir_lookup (struct protid *dircred,
       goto out;
     }
 
-  free (newpi->po->path);
-  if (dircred->po->path == NULL || !strcmp (dircred->po->path,"."))
+  mach_port_t rendezvous = MACH_PORT_NULL;
+  struct flock64 lock =
     {
-      /* dircred is the root directory.  */
-      newpi->po->path = relpath;
-      relpath = NULL; /* Do not free relpath.  */
+    l_start: 0,
+    l_len: 0,
+    l_whence: SEEK_SET
+    };
+
+  if (flags & O_EXLOCK)
+    {
+      lock.l_type = F_WRLCK;
+      err = fshelp_rlock_tweak (&np->userlock, &np->lock,
+				&newpi->po->lock_status, flags, 0, 0,
+				F_SETLK64, &lock, rendezvous);
     }
-  else
+  else if (flags & O_SHLOCK)
     {
-      newpi->po->path = NULL;
-      asprintf (&newpi->po->path, "%s/%s", dircred->po->path, relpath);
+      lock.l_type = F_RDLCK;
+      err = fshelp_rlock_tweak (&np->userlock, &np->lock,
+				&newpi->po->lock_status, flags, 0, 0,
+				F_SETLK64, &lock, rendezvous);
     }
 
-  if (! newpi->po->path)
-    err = errno;
+  if (! err)
+    {
+      free (newpi->po->path);
+      if (dircred->po->path == NULL || !strcmp (dircred->po->path,"."))
+	{
+	  /* dircred is the root directory.  */
+	  newpi->po->path = relpath;
+	  relpath = NULL; /* Do not free relpath.  */
+	}
+      else
+	{
+	  newpi->po->path = NULL;
+	  asprintf (&newpi->po->path, "%s/%s", dircred->po->path, relpath);
+	}
+
+      if (! newpi->po->path)
+	err = errno;
 
-  *retry_port = ports_get_right (newpi);
-  ports_port_deref (newpi);
+      *retry_port = ports_get_right (newpi);
+      ports_port_deref (newpi);
+    }
 
  out:
   if (np)
diff --git a/libnetfs/file-lock-stat.c b/libnetfs/file-lock-stat.c
index 49529cf4..c2145918 100644
--- a/libnetfs/file-lock-stat.c
+++ b/libnetfs/file-lock-stat.c
@@ -1,5 +1,5 @@
-/* 
-   Copyright (C) 1995 Free Software Foundation, Inc.
+/*
+   Copyright (C) 1995, 2015-2019 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -15,23 +15,30 @@
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "netfs.h"
 #include "fs_S.h"
 
+#include <fcntl.h>
+#include <sys/file.h>
+
 error_t
 netfs_S_file_lock_stat (struct protid *user,
 			int *mystatus,
 			int *otherstatus)
 {
+
+  struct node *node;
+
   if (!user)
     return EOPNOTSUPP;
-  
-  pthread_mutex_lock (&user->po->np->lock);
-  *mystatus = user->po->lock_status;
-  *otherstatus = user->po->np->userlock.type;
-  pthread_mutex_unlock (&user->po->np->lock);
+
+  node = user->po->np;
+  pthread_mutex_lock (&node->lock);
+  *mystatus = fshelp_rlock_peropen_status (&user->po->lock_status);
+  *otherstatus = fshelp_rlock_node_status (&node->userlock);
+  pthread_mutex_unlock (&node->lock);
+
   return 0;
 }
diff --git a/libnetfs/file-lock.c b/libnetfs/file-lock.c
index 0010d4be..7bb81d43 100644
--- a/libnetfs/file-lock.c
+++ b/libnetfs/file-lock.c
@@ -1,5 +1,5 @@
-/* 
-   Copyright (C) 1995 Free Software Foundation, Inc.
+/*
+   Copyright (C) 1995, 2015-2019 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -15,22 +15,54 @@
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "netfs.h"
 #include "fs_S.h"
 
+#include <fcntl.h>
+#include <sys/file.h>
+
 error_t
 netfs_S_file_lock (struct protid *user,
 		   int flags)
 {
   error_t err;
+  struct flock64 lock;
+  struct node *node;
+  int openstat = user->po->openstat;
+  mach_port_t rendezvous = MACH_PORT_NULL;
+
   if (!user)
     return EOPNOTSUPP;
-  pthread_mutex_lock (&user->po->np->lock);
-  err = fshelp_acquire_lock (&user->po->np->userlock, &user->po->lock_status,
-			     &user->po->np->lock, flags);
-  pthread_mutex_unlock (&user->po->np->lock);
+
+  lock.l_whence = SEEK_SET;
+  lock.l_start = 0;
+  lock.l_len = 0;
+
+  if (flags & LOCK_UN)
+    lock.l_type = F_UNLCK;
+  else if (flags & LOCK_SH)
+    lock.l_type = F_RDLCK;
+  else if (flags & LOCK_EX)
+    lock.l_type = F_WRLCK;
+  else
+    return EINVAL;
+
+  /*
+    XXX: Fix for flock(2) calling fcntl(2)
+    From flock(2): A shared or exclusive lock can be placed on a file
+    regardless of the mode in which the file was opened.
+  */
+  if (openstat & (O_RDONLY|O_WRONLY|O_EXEC)) openstat |= O_RDONLY|O_WRONLY;
+
+  node = user->po->np;
+  pthread_mutex_lock (&node->lock);
+  err = fshelp_rlock_tweak (&node->userlock, &node->lock,
+			    &user->po->lock_status, openstat,
+			    0, 0, flags & LOCK_NB ? F_SETLK64 : F_SETLKW64,
+			    &lock, rendezvous);
+  pthread_mutex_unlock (&node->lock);
+
   return err;
 }
diff --git a/libnetfs/file-record-lock.c b/libnetfs/file-record-lock.c
new file mode 100644
index 00000000..049fc139
--- /dev/null
+++ b/libnetfs/file-record-lock.c
@@ -0,0 +1,44 @@
+/* Copyright (C) 2001, 2014-2019 Free Software Foundation, Inc.
+
+   Written by Neal H Walfield <neal@cs.uml.edu>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "netfs.h"
+
+#include <hurd/fshelp.h>
+
+error_t
+netfs_S_file_record_lock (struct protid *cred,
+			  int cmd,
+			  struct flock64 *lock,
+			  mach_port_t rendezvous)
+{
+  struct node *node;
+  error_t err;
+
+  if (! cred)
+    return EOPNOTSUPP;
+
+  node = cred->po->np;
+  pthread_mutex_lock (&node->lock);
+  err = fshelp_rlock_tweak (&node->userlock, &node->lock,
+			    &cred->po->lock_status, cred->po->openstat,
+			    node->nn_stat.st_size, cred->po->filepointer,
+			    cmd, lock, rendezvous);
+  pthread_mutex_unlock (&node->lock);
+  return err;
+}
diff --git a/libnetfs/make-node.c b/libnetfs/make-node.c
index a292dc62..ab3b8850 100644
--- a/libnetfs/make-node.c
+++ b/libnetfs/make-node.c
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1995, 1996, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 2000, 2015-2019 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -15,8 +15,7 @@
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "netfs.h"
 #include <hurd/fshelp.h>
@@ -32,7 +31,7 @@ init_node (struct node *np, struct netnode *nn)
   np->owner = 0;
 
   fshelp_transbox_init (&np->transbox, &np->lock, np);
-  fshelp_lock_init (&np->userlock);
+  fshelp_rlock_init (&np->userlock);
   
   return np;
 }
diff --git a/libnetfs/make-peropen.c b/libnetfs/make-peropen.c
index 413e9140..4bd74740 100644
--- a/libnetfs/make-peropen.c
+++ b/libnetfs/make-peropen.c
@@ -1,5 +1,5 @@
-/* 
-   Copyright (C) 1995, 1997 Free Software Foundation, Inc.
+/*
+   Copyright (C) 1995, 1997, 2015-2019 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -15,22 +15,26 @@
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "netfs.h"
+#include <errno.h>
+#include <stdlib.h>
 #include <sys/file.h>
 
 struct peropen *
 netfs_make_peropen (struct node *np, int flags, struct peropen *context)
 {
+  error_t err;
   struct peropen *po = malloc (sizeof (struct peropen));
 
   if (!po)
     return NULL;
 
   po->filepointer = 0;
-  po->lock_status = LOCK_UN;
+  err = fshelp_rlock_po_init (&po->lock_status);
+  if (err)
+    return NULL;
   refcount_init (&po->refcnt, 1);
   po->openstat = flags;
   po->np = np;
diff --git a/libnetfs/netfs.h b/libnetfs/netfs.h
index 625aa963..d6a13bb1 100644
--- a/libnetfs/netfs.h
+++ b/libnetfs/netfs.h
@@ -1,6 +1,6 @@
 /*
-
-   Copyright (C) 1994,95,96,97,99,2000,02,13 Free Software Foundation, Inc.
+   Copyright (C) 1994-1997, 1999, 2000, 2002, 2013-2019
+   Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
@@ -13,8 +13,7 @@
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #ifndef _HURD_NETFS_H_
 #define _HURD_NETFS_H_
@@ -24,6 +23,7 @@
 #include <hurd/iohelp.h>
 #include <assert-backtrace.h>
 #include <pthread.h>
+#include <refcount.h>
 
 /* This library supports client-side network file system
    implementations.  It is analogous to the diskfs library provided for
@@ -50,7 +50,7 @@ struct protid
 struct peropen
 {
   loff_t filepointer;
-  int lock_status;
+  struct rlock_peropen lock_status;
   refcount_t refcnt;
   int openstat;
 
@@ -93,7 +93,7 @@ struct node
 
   struct transbox transbox;
 
-  struct lock_box userlock;
+  struct rlock_box userlock;
 
   struct conch conch;
 
diff --git a/libnetfs/release-peropen.c b/libnetfs/release-peropen.c
index 01af97dd..2ef83183 100644
--- a/libnetfs/release-peropen.c
+++ b/libnetfs/release-peropen.c
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 2015-2019 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -15,8 +15,7 @@
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <sys/file.h>
 #include "netfs.h"
@@ -39,9 +38,7 @@ netfs_release_peropen (struct peropen *po)
   if (po->shadow_root_parent)
     mach_port_deallocate (mach_task_self (), po->shadow_root_parent);
 
-  if (po->lock_status != LOCK_UN)
-    fshelp_acquire_lock (&po->np->userlock, &po->lock_status,
-			 &po->np->lock, LOCK_UN);
+  fshelp_rlock_drop_peropen (&po->lock_status);
 
   netfs_nput (po->np);