libdiskfs: 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(diskfs_S_file_record_lock):
          Don't set rendezvous to MACH_PORT_NULL.

2018-12-07  Svante Signell <svante.signell@gmail.com>

        * Update copyright years.
        * dir-lookup.c(diskfs_S_dir_lookup): Call fshelp_rlock_tweak()
          with new last argument rendezvous = MACH_PORT_NULL.
        * file-lock.c(diskfs_S_file_lock): Likewise.
        * file-record-lock.c(diskfs_S_file_record_lock): Likewise.
        (diskfs_S_file_record_lock): Add new argument mach_port_t rendezvous.

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

        * Update copyright years and headers.

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

        * file-lock-stat.c: Port from cthreads to libpthread.
        * file-lock.c: Likewise.
        * file-record-lock: Likewise.

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

        * Makefile (FSSRCS): Add file-record-lock.c.
        * diskfs.h (struct peropen): Change the type of lock_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 (diskfs_S_dir_lookup): Use fshelp_rlock_tweak
        as fshelp_acquire_lock is now depreciated.
        * file-lock-stat.c (diskfs_S_file_lock_stat): Total rewrite
        around the new record locking functions.
        * file-lock.c (diskfs_S_file_lock): Total rewrite around the
        new record locking functions.
        * file-record-lock.c: New file.  Implement
        diskfs_S_file_record_lock.
        * node-make.c (diskfs_make_node):  Initialize userbox with
        fshelp_rlock_init.
        * peropen-make.c (diskfs_make_peropen): Initialize lock_status
        using fshelp_rlock_po_init.
        * peropen-rele.c (diskfs_release_peropen): Release lock_status
        using fshelp_rlock_drop_peropen.

9 files changed, 169 insertions, 78 deletions

diff --git a/libdiskfs/Makefile b/libdiskfs/Makefile
index 5716ac5b..66c9f53e 100644
--- a/libdiskfs/Makefile
+++ b/libdiskfs/Makefile
@@ -1,4 +1,4 @@
-#   Copyright (C) 1994,95,96,97,98,99,2000,01,2006,2012
+#   Copyright (C) 1994,95,96,97,98,99,2000,01,2006,2012,2016-2019
 #     Free Software Foundation, Inc.
 #
 #   This program is free software; you can redistribute it and/or
@@ -12,8 +12,7 @@
 #   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/>.
 
 dir := libdiskfs
 makemode := library
@@ -26,7 +25,8 @@ FSSRCS= dir-chg.c dir-link.c dir-lookup.c dir-mkdir.c dir-mkfile.c \
 	file-get-trans.c file-get-transcntl.c file-getcontrol.c \
 	file-getfh.c file-getlinknode.c file-lock-stat.c \
 	file-lock.c file-set-size.c file-set-trans.c file-statfs.c \
-	file-sync.c file-syncfs.c file-utimes.c file-reparent.c
+	file-sync.c file-syncfs.c file-utimes.c file-record-lock.c \
+	file-reparent.c
 IOSRCS= io-async-icky.c io-async.c io-duplicate.c io-get-conch.c io-revoke.c \
 	io-map-cntl.c io-map.c io-modes-get.c io-modes-off.c \
 	io-modes-on.c io-modes-set.c io-owner-mod.c io-owner-get.c \
diff --git a/libdiskfs/dir-lookup.c b/libdiskfs/dir-lookup.c
index 9ebe3b45..16eb22e3 100644
--- a/libdiskfs/dir-lookup.c
+++ b/libdiskfs/dir-lookup.c
@@ -1,6 +1,7 @@
 /* libdiskfs implementation of fs.defs:dir_lookup
-   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
-     2002, 2008, 2013, 2014 Free Software Foundation, Inc.
+
+   Copyright (C) 1992-2002, 2008, 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 +14,7 @@
    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/>.  */
 
 #include <stdio.h>
 #include <fcntl.h>
@@ -499,12 +499,28 @@ diskfs_S_dir_lookup (struct protid *dircred,
   if (! err)
     {
       newpo = 0;
+      mach_port_t rendezvous = MACH_PORT_NULL;
+      struct flock64 lock =
+        {
+         l_start: 0,
+         l_len: 0,
+         l_whence: SEEK_SET
+       };
+
       if (flags & O_EXLOCK)
-	err = fshelp_acquire_lock (&np->userlock, &newpi->po->lock_status,
-				     &np->lock, LOCK_EX);
+        {
+         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 if (flags & O_SHLOCK)
-	err = fshelp_acquire_lock (&np->userlock, &newpi->po->lock_status,
-				     &np->lock, LOCK_SH);
+        {
+         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 (! err)
diff --git a/libdiskfs/diskfs.h b/libdiskfs/diskfs.h
index c949ec07..272dd57e 100644
--- a/libdiskfs/diskfs.h
+++ b/libdiskfs/diskfs.h
@@ -1,7 +1,7 @@
 /* Definitions for fileserver helper functions
 
-   Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2007, 2008,
-   2009, 2013 Free Software Foundation, Inc.
+   Copyright (C) 1994-1999, 2001, 2002, 2007-2009, 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
@@ -14,8 +14,7 @@
    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_DISKFS
 #define _HURD_DISKFS
@@ -58,7 +57,7 @@ struct protid
 struct peropen
 {
   loff_t filepointer;
-  int lock_status;
+  struct rlock_peropen lock_status;
   refcount_t refcnt;
   int openstat;
 
@@ -113,7 +112,7 @@ struct node
 
   struct transbox transbox;
 
-  struct lock_box userlock;
+  struct rlock_box userlock;
 
   struct conch conch;
 
diff --git a/libdiskfs/file-lock-stat.c b/libdiskfs/file-lock-stat.c
index a31ad9a2..c6990c46 100644
--- a/libdiskfs/file-lock-stat.c
+++ b/libdiskfs/file-lock-stat.c
@@ -1,38 +1,42 @@
-/*
-   Copyright (C) 1994, 1995 Free Software Foundation
+/* Copyright (C) 1994-1995, 2001, 2014-2019 Free Software Foundation, Inc.
 
-   This file is part of the GNU Hurd.
+   Written by Neal H Walfield <neal@cs.uml.edu>
 
-   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.
+   This program 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.
+   This program 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; see the file COPYING.  If not, write to
-   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
-
-/* Written by Michael I. Bushnell.  */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "priv.h"
 #include "fs_S.h"
 
+#include <fcntl.h>
+#include <sys/file.h>
+
 kern_return_t
 diskfs_S_file_lock_stat (struct protid *cred,
 			 int *mystatus,
 			 int *otherstatus)
 {
+  struct node *node;
+
   if (!cred)
     return EOPNOTSUPP;
-  
-  pthread_mutex_lock (&cred->po->np->lock);
-  *mystatus = cred->po->lock_status;
-  *otherstatus = cred->po->np->userlock.type;
-  pthread_mutex_unlock (&cred->po->np->lock);
+
+  node = cred->po->np;
+
+  pthread_mutex_lock (&node->lock);
+  *mystatus = fshelp_rlock_peropen_status (&cred->po->lock_status);
+  *otherstatus = fshelp_rlock_node_status (&node->userlock);
+  pthread_mutex_unlock (&node->lock);
+
   return 0;
 }
diff --git a/libdiskfs/file-lock.c b/libdiskfs/file-lock.c
index ab536e86..b95c3f0c 100644
--- a/libdiskfs/file-lock.c
+++ b/libdiskfs/file-lock.c
@@ -1,36 +1,64 @@
-/*
-   Copyright (C) 1993, 1994 Free Software Foundation
+/* Copyright (C) 1993-1994, 2001, 2014-2019 Free Software Foundation, Inc.
 
-   This file is part of the GNU Hurd.
+   Written by Neal H Walfield <neal@cs.uml.edu>
 
-   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.
+   This program 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.
+   This program 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; see the file COPYING.  If not, write to
-   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
-
-/* Written by Michael I. Bushnell.  */
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "priv.h"
 #include "fs_S.h"
 
+#include <fcntl.h>
+#include <sys/file.h>
+
 kern_return_t
 diskfs_S_file_lock (struct protid *cred, int flags)
 {
   error_t err;
-  if (!cred)
+  struct flock64 lock;
+  struct node *node;
+  int openstat = cred->po->openstat;
+  mach_port_t rendezvous = MACH_PORT_NULL;
+
+  if (! cred)
     return EOPNOTSUPP;
-  pthread_mutex_lock (&cred->po->np->lock);
-  err = fshelp_acquire_lock (&cred->po->np->userlock, &cred->po->lock_status,
-			     &cred->po->np->lock, flags);
-  pthread_mutex_unlock (&cred->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 = cred->po->np;
+  pthread_mutex_lock (&node->lock);
+  err = fshelp_rlock_tweak (&node->userlock, &node->lock,
+			    &cred->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/libdiskfs/file-record-lock.c b/libdiskfs/file-record-lock.c
new file mode 100644
index 00000000..a3ce9f42
--- /dev/null
+++ b/libdiskfs/file-record-lock.c
@@ -0,0 +1,45 @@
+/* Copyright (C) 2001, 2014-2019 Free Software Foundation, Inc.
+
+   Written by Neal H Walfield <neal@cs.uml.edu>
+
+   This program 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.
+
+   This program 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 "priv.h"
+#include "diskfs.h"
+#include "fs_S.h"
+
+#include <errno.h>
+#include <hurd/fshelp.h>
+
+error_t
+diskfs_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->dn_stat.st_size, cred->po->filepointer,
+			    cmd, lock, rendezvous);
+  pthread_mutex_unlock (&node->lock);
+  return err;
+}
diff --git a/libdiskfs/node-make.c b/libdiskfs/node-make.c
index 7bc1d854..386714c2 100644
--- a/libdiskfs/node-make.c
+++ b/libdiskfs/node-make.c
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 1994,95,96,2002 Free Software Foundation, Inc.
+   Copyright (C) 1994-1996, 2002, 2014-2019 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
@@ -12,8 +12,7 @@
    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/>.  */
 
 #include "priv.h"
 #include <fcntl.h>
@@ -41,7 +40,7 @@ init_node (struct node *np, struct disknode *dn)
 
   fshelp_transbox_init (&np->transbox, &np->lock, np);
   iohelp_initialize_conch (&np->conch, &np->lock);
-  fshelp_lock_init (&np->userlock);
+  fshelp_rlock_init (&np->userlock);
 
   return np;
 }
diff --git a/libdiskfs/peropen-make.c b/libdiskfs/peropen-make.c
index 788b9a7a..827aa2d8 100644
--- a/libdiskfs/peropen-make.c
+++ b/libdiskfs/peropen-make.c
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1994,97,99,2001,02 Free Software Foundation
+   Copyright (C) 1994,97,99,2001-2002,2014-2019 Free Software Foundation
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
@@ -12,11 +12,13 @@
    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/>.  */
 
 #include "priv.h"
+#include <errno.h>
+#include <stdlib.h>
 #include <sys/file.h>
+#include <hurd/fshelp.h>
 
 /* Create and return a new peropen structure on node NP with open
    flags FLAGS.  */
@@ -24,13 +26,17 @@ error_t
 diskfs_make_peropen (struct node *np, int flags, struct peropen *context,
 		     struct peropen **ppo)
 {
+  error_t err;
   struct peropen *po = *ppo = malloc (sizeof (struct peropen));
 
   if (! po)
     return ENOMEM;
 
+  err = fshelp_rlock_po_init (&po->lock_status);
+  if (err)
+    return err;
+
   po->filepointer = 0;
-  po->lock_status = LOCK_UN;
   refcount_init (&po->refcnt, 1);
   po->openstat = flags;
   po->np = np;
diff --git a/libdiskfs/peropen-rele.c b/libdiskfs/peropen-rele.c
index 877137bb..e8d83b55 100644
--- a/libdiskfs/peropen-rele.c
+++ b/libdiskfs/peropen-rele.c
@@ -1,5 +1,5 @@
-/* 
-   Copyright (C) 1994, 1996, 1997 Free Software Foundation
+/*
+   Copyright (C) 1994, 1996, 1997, 2014-2019 Free Software Foundation
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
@@ -12,8 +12,7 @@
    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/>.  */
 
 #include <sys/file.h>
 #include "priv.h"
@@ -33,14 +32,9 @@ diskfs_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)
-    {
-      pthread_mutex_lock (&po->np->lock);
-      fshelp_acquire_lock (&po->np->userlock, &po->lock_status,
-                           &po->np->lock, LOCK_UN);
-      diskfs_nput (po->np);
-    }
+  fshelp_rlock_drop_peropen (&po->lock_status);
+  if (fshelp_rlock_peropen_status(&po->lock_status) != LOCK_UN)
+    diskfs_nput (po->np);
   else
     diskfs_nrele (po->np);