a major share modes reorganisation.

The shares modes code is now split into separate files. The shared
memory implementation is in locking_shm.c. The slow implementation is
in locking_slow.c

It is all controlled by a struct share_ops structure that has function
pointers to the implementation of all the functions needed by a share
modes implementation. An initialisation function sets up this
structure. This will make adding new implementations easy and clean.

This also allowed me to get rid of the ugly code in smbstatus. Now
status.c links to the locking code and calls methods in share_ops.

I also renamed some things and generally organised things in a much
cleaner fashion. Defines and structures specific to each
implementation have been moved to the appropriate file and out of
smb.h.
(This used to be commit 65ab9adaa0d356b8041ed8a507ea52117f2a284e)

1 files changed, 1039 insertions, 0 deletions

diff --git a/source3/locking/locking_slow.c b/source3/locking/locking_slow.c
new file mode 100644
index 0000000000..cc646c6ca6
--- /dev/null
+++ b/source3/locking/locking_slow.c
@@ -0,0 +1,1039 @@
+/* 
+   Unix SMB/Netbios implementation.
+   Version 1.9.
+   slow (lockfile) locking implementation
+   Copyright (C) Andrew Tridgell 1992-1997
+   
+   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 of the License, 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 this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   Revision History:
+
+   12 aug 96: Erik.Devriendt@te6.siemens.be
+   added support for shared memory implementation of share mode locking
+
+   May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
+   locking to deal with multiple share modes per open file.
+
+   September 1997. Jeremy Allison (jallison@whistle.com). Added oplock
+   support.
+
+   October 1997 - split into separate file (tridge)
+*/
+
+#include "includes.h"
+extern int DEBUGLEVEL;
+extern connection_struct Connections[];
+extern files_struct Files[];
+
+/* 
+ * Locking file header lengths & offsets. 
+ */
+#define SMF_VERSION_OFFSET 0
+#define SMF_NUM_ENTRIES_OFFSET 4
+#define SMF_FILENAME_LEN_OFFSET 8
+#define SMF_HEADER_LENGTH 10
+
+#define SMF_ENTRY_LENGTH 20
+
+/*
+ * Share mode record offsets.
+ */
+
+#define SME_SEC_OFFSET 0
+#define SME_USEC_OFFSET 4
+#define SME_SHAREMODE_OFFSET 8
+#define SME_PID_OFFSET 12
+#define SME_PORT_OFFSET 16
+#define SME_OPLOCK_TYPE_OFFSET 18
+
+
+/*******************************************************************
+  deinitialize share_mode management 
+  ******************************************************************/
+static BOOL slow_stop_share_mode_mgmt(void)
+{
+   return True;
+}
+
+
+/*******************************************************************
+  name a share file
+  ******************************************************************/
+static BOOL share_name(int cnum, uint32 dev, uint32 inode, char *name)
+{
+  strcpy(name,lp_lockdir());
+  trim_string(name,"","/");
+  if (!*name) return(False);
+  name += strlen(name);
+  
+  sprintf(name,"/share.%u.%u",dev,inode);
+  return(True);
+}
+
+/*******************************************************************
+Force a share file to be deleted.
+********************************************************************/
+static int delete_share_file( int cnum, char *fname )
+{
+  /* the share file could be owned by anyone, so do this as root */
+  become_root(False);
+
+  if(unlink(fname) != 0)
+  {
+    DEBUG(0,("delete_share_file: Can't delete share file %s (%s)\n",
+            fname, strerror(errno)));
+  } 
+  else 
+  {
+    DEBUG(5,("delete_share_file: Deleted share file %s\n", fname));
+  }
+
+  /* return to our previous privilage level */
+  unbecome_root(False);
+
+  return 0;
+}
+
+/*******************************************************************
+  lock a share mode file.
+  ******************************************************************/
+static BOOL slow_lock_share_entry(int cnum, uint32 dev, uint32 inode, int *ptok)
+{
+  pstring fname;
+  int fd;
+  int ret = True;
+
+  *ptok = (int)-1;
+
+  if(!share_name(cnum, dev, inode, fname))
+    return False;
+
+  /* we need to do this as root */
+  become_root(False);
+
+  {
+    int old_umask;
+    BOOL gotlock = False;
+    old_umask = umask(0);
+
+    /*
+     * There was a race condition in the original slow share mode code.
+     * A smbd could open a share mode file, and before getting
+     * the lock, another smbd could delete the last entry for
+     * the share mode file and delete the file entry from the
+     * directory. Thus this smbd would be left with a locked
+     * share mode fd attached to a file that no longer had a
+     * directory entry. Thus another smbd would think that
+     * there were no outstanding opens on the file. To fix
+     * this we now check we can do a stat() call on the filename
+     * before allowing the lock to proceed, and back out completely
+     * and try the open again if we cannot.
+     * Jeremy Allison (jallison@whistle.com).
+     */
+
+    do
+    {
+      struct stat dummy_stat;
+
+#ifdef SECURE_SHARE_MODES
+      fd = (int)open(fname,O_RDWR|O_CREAT,0600);
+#else /* SECURE_SHARE_MODES */
+      fd = (int)open(fname,O_RDWR|O_CREAT,0666);
+#endif /* SECURE_SHARE_MODES */
+
+      if(fd < 0)
+      {
+        DEBUG(0,("ERROR lock_share_entry: failed to open share file %s. Error was %s\n",
+                  fname, strerror(errno)));
+        ret = False;
+        break;
+      }
+
+       /* At this point we have an open fd to the share mode file. 
+         Lock the first byte exclusively to signify a lock. */
+      if(fcntl_lock(fd, F_SETLKW, 0, 1, F_WRLCK) == False)
+      {
+        DEBUG(0,("ERROR lock_share_entry: fcntl_lock on file %s failed with %s\n",
+                  fname, strerror(errno)));   
+        close(fd);
+        ret = False;
+        break;
+      }
+
+      /* 
+       * If we cannot stat the filename, the file was deleted between
+       * the open and the lock call. Back out and try again.
+       */
+
+      if(stat(fname, &dummy_stat)!=0)
+      {
+        DEBUG(2,("lock_share_entry: Re-issuing open on %s to fix race. Error was %s\n",
+                fname, strerror(errno)));
+        close(fd);
+      }
+      else
+        gotlock = True;
+    } while(!gotlock);
+
+    /*
+     * We have to come here if any of the above calls fail
+     * as we don't want to return and leave ourselves running
+     * as root !
+     */
+
+    umask(old_umask);
+  }
+
+  *ptok = (int)fd;
+
+  /* return to our previous privilage level */
+  unbecome_root(False);
+
+  return ret;
+}
+
+/*******************************************************************
+  unlock a share mode file.
+  ******************************************************************/
+static BOOL slow_unlock_share_entry(int cnum, uint32 dev, uint32 inode, int token)
+{
+  int fd = (int)token;
+  int ret = True;
+  struct stat sb;
+  pstring fname;
+
+  /* Fix for zero length share files from
+     Gerald Werner <wernerg@mfldclin.edu> */
+    
+  share_name(cnum, dev, inode, fname);
+
+  /* get the share mode file size */
+  if(fstat((int)token, &sb) != 0)
+  {
+    DEBUG(0,("ERROR: unlock_share_entry: Failed to do stat on share file %s (%s)\n",
+              fname, strerror(errno)));
+    sb.st_size = 1;
+    ret = False;
+  }
+
+  /* If the file was zero length, we must delete before
+     doing the unlock to avoid a race condition (see
+     the code in lock_share_mode_entry for details.
+   */
+
+  /* remove the share file if zero length */    
+  if(sb.st_size == 0)  
+    delete_share_file(cnum, fname);
+
+  /* token is the fd of the open share mode file. */
+  /* Unlock the first byte. */
+  if(fcntl_lock(fd, F_SETLKW, 0, 1, F_UNLCK) == False)
+   { 
+      DEBUG(0,("ERROR unlock_share_entry: fcntl_lock failed with %s\n",
+                      strerror(errno)));   
+      ret = False;
+   }
+ 
+  close(fd);
+  return ret;
+}
+
+/*******************************************************************
+Read a share file into a buffer.
+********************************************************************/
+static int read_share_file(int cnum, int fd, char *fname, char **out, BOOL *p_new_file)
+{
+  struct stat sb;
+  char *buf;
+  int size;
+
+  *out = 0;
+  *p_new_file = False;
+
+  if(fstat(fd, &sb) != 0)
+  {
+    DEBUG(0,("ERROR: read_share_file: Failed to do stat on share file %s (%s)\n",
+                  fname, strerror(errno)));
+    return -1;
+  }
+
+  if(sb.st_size == 0)
+  {
+     *p_new_file = True;
+     return 0;
+  }
+
+  /* Allocate space for the file */
+  if((buf = (char *)malloc(sb.st_size)) == NULL)
+  {
+    DEBUG(0,("read_share_file: malloc for file size %d fail !\n", sb.st_size));
+    return -1;
+  }
+  
+  if(lseek(fd, 0, SEEK_SET) != 0)
+  {
+    DEBUG(0,("ERROR: read_share_file: Failed to reset position to 0 \
+for share file %s (%s)\n", fname, strerror(errno)));
+    if(buf)
+      free(buf);
+    return -1;
+  }
+  
+  if (read(fd,buf,sb.st_size) != sb.st_size)
+  {
+    DEBUG(0,("ERROR: read_share_file: Failed to read share file %s (%s)\n",
+               fname, strerror(errno)));
+    if(buf)
+      free(buf);
+    return -1;
+  }
+  
+  if (IVAL(buf,SMF_VERSION_OFFSET) != LOCKING_VERSION) {
+    DEBUG(0,("ERROR: read_share_file: share file %s has incorrect \
+locking version (was %d, should be %d).\n",fname, 
+                    IVAL(buf,SMF_VERSION_OFFSET), LOCKING_VERSION));
+   if(buf)
+      free(buf);
+    delete_share_file(cnum, fname);
+    return -1;
+  }
+
+  /* Sanity check for file contents */
+  size = sb.st_size;
+  size -= SMF_HEADER_LENGTH; /* Remove the header */
+
+  /* Remove the filename component. */
+  size -= SVAL(buf, SMF_FILENAME_LEN_OFFSET);
+
+  /* The remaining size must be a multiple of SMF_ENTRY_LENGTH - error if not. */
+  if((size % SMF_ENTRY_LENGTH) != 0)
+  {
+    DEBUG(0,("ERROR: read_share_file: share file %s is an incorrect length - \
+deleting it.\n", fname));
+    if(buf)
+      free(buf);
+    delete_share_file(cnum, fname);
+    return -1;
+  }
+
+  *out = buf;
+  return 0;
+}
+
+/*******************************************************************
+get all share mode entries in a share file for a dev/inode pair.
+********************************************************************/
+static int slow_get_share_modes(int cnum, int token, uint32 dev, uint32 inode, 
+				share_mode_entry **old_shares)
+{
+  int fd = (int)token;
+  pstring fname;
+  int i;
+  int num_entries;
+  int num_entries_copied;
+  int newsize;
+  share_mode_entry *share_array;
+  char *buf = 0;
+  char *base = 0;
+  BOOL new_file;
+
+  *old_shares = 0;
+
+  /* Read the share file header - this is of the form:
+     0   -  locking version.
+     4   -  number of share mode entries.
+     8   -  2 byte name length
+     [n bytes] file name (zero terminated).
+
+   Followed by <n> share mode entries of the form :
+
+     0   -  tv_sec
+     4   -  tv_usec
+     8   -  share_mode
+    12   -  pid
+    16   -  oplock port (if oplocks in use) - 2 bytes.
+  */
+
+  share_name(cnum, dev, inode, fname);
+
+  if(read_share_file( cnum, fd, fname, &buf, &new_file) != 0)
+  {
+    DEBUG(0,("ERROR: get_share_modes: Failed to read share file %s\n",
+                  fname));
+    return 0;
+  }
+
+  if(new_file == True)
+    return 0;
+
+  num_entries = IVAL(buf,SMF_NUM_ENTRIES_OFFSET);
+
+  DEBUG(5,("get_share_modes: share file %s has %d share mode entries.\n",
+            fname, num_entries));
+
+  /* PARANOIA TEST */
+  if(num_entries < 0)
+  {
+    DEBUG(0,("PANIC ERROR:get_share_mode: num_share_mode_entries < 0 (%d) \
+for share file %d\n", num_entries, fname));
+    return 0;
+  }
+
+  if(num_entries)
+  {
+    *old_shares = share_array = (share_mode_entry *)
+                 malloc(num_entries * sizeof(share_mode_entry));
+    if(*old_shares == 0)
+    {
+      DEBUG(0,("get_share_modes: malloc fail !\n"));
+      return 0;
+    }
+  } 
+  else
+  {
+    /* No entries - just delete the file. */
+    DEBUG(0,("get_share_modes: share file %s has no share mode entries - deleting.\n",
+              fname));
+    if(buf)
+      free(buf);
+    delete_share_file(cnum, fname);
+    return 0;
+  }
+
+  num_entries_copied = 0;
+  base = buf + SMF_HEADER_LENGTH + SVAL(buf,SMF_FILENAME_LEN_OFFSET);
+
+  for( i = 0; i < num_entries; i++)
+  {
+    int pid;
+    char *p = base + (i*SMF_ENTRY_LENGTH);
+
+    pid = IVAL(p,SME_PID_OFFSET);
+
+    if(!process_exists(pid))
+    {
+      DEBUG(0,("get_share_modes: process %d no longer exists and \
+it left a share mode entry with mode 0x%X in share file %s\n",
+            pid, IVAL(p,SME_SHAREMODE_OFFSET), fname));
+      continue;
+    }
+    share_array[num_entries_copied].time.tv_sec = IVAL(p,SME_SEC_OFFSET);
+    share_array[num_entries_copied].time.tv_usec = IVAL(p,SME_USEC_OFFSET);
+    share_array[num_entries_copied].share_mode = IVAL(p,SME_SHAREMODE_OFFSET);
+    share_array[num_entries_copied].pid = pid;
+    share_array[num_entries_copied].op_port = SVAL(p,SME_PORT_OFFSET);
+    share_array[num_entries_copied].op_type = SVAL(p,SME_OPLOCK_TYPE_OFFSET);
+
+    num_entries_copied++;
+  }
+
+  if(num_entries_copied == 0)
+  {
+    /* Delete the whole file. */
+    DEBUG(0,("get_share_modes: share file %s had no valid entries - deleting it !\n",
+             fname));
+    if(*old_shares)
+      free((char *)*old_shares);
+    *old_shares = 0;
+    if(buf)
+      free(buf);
+    delete_share_file(cnum, fname);
+    return 0;
+  }
+
+  /* If we deleted some entries we need to re-write the whole number of
+     share mode entries back into the file. */
+
+  if(num_entries_copied != num_entries)
+  {
+    if(lseek(fd, 0, SEEK_SET) != 0)
+    {
+      DEBUG(0,("ERROR: get_share_modes: lseek failed to reset to \
+position 0 for share mode file %s (%s)\n", fname, strerror(errno)));
+      if(*old_shares)
+        free((char *)*old_shares);
+      *old_shares = 0;
+      if(buf)
+        free(buf);
+      return 0;
+    }
+
+    SIVAL(buf, SMF_NUM_ENTRIES_OFFSET, num_entries_copied);
+    for( i = 0; i < num_entries_copied; i++)
+    {
+      char *p = base + (i*SMF_ENTRY_LENGTH);
+
+      SIVAL(p,SME_PID_OFFSET,share_array[i].pid);
+      SIVAL(p,SME_SHAREMODE_OFFSET,share_array[i].share_mode);
+      SIVAL(p,SME_SEC_OFFSET,share_array[i].time.tv_sec);
+      SIVAL(p,SME_USEC_OFFSET,share_array[i].time.tv_usec);
+      SSVAL(p,SME_PORT_OFFSET,share_array[i].op_port);
+      SSVAL(p,SME_OPLOCK_TYPE_OFFSET,share_array[i].op_type);
+    }
+
+    newsize = (base - buf) + (SMF_ENTRY_LENGTH*num_entries_copied);
+    if(write(fd, buf, newsize) != newsize)
+    {
+      DEBUG(0,("ERROR: get_share_modes: failed to re-write share \
+mode file %s (%s)\n", fname, strerror(errno)));
+      if(*old_shares)
+        free((char *)*old_shares);
+      *old_shares = 0;
+      if(buf)
+        free(buf);
+      return 0;
+    }
+    /* Now truncate the file at this point. */
+    if(ftruncate(fd, newsize)!= 0)
+    {
+      DEBUG(0,("ERROR: get_share_modes: failed to ftruncate share \
+mode file %s to size %d (%s)\n", fname, newsize, strerror(errno)));
+      if(*old_shares)
+        free((char *)*old_shares);
+      *old_shares = 0;
+      if(buf)
+        free(buf);
+      return 0;
+    }
+  }
+
+  if(buf)
+    free(buf);
+
+  DEBUG(5,("get_share_modes: Read share file %s returning %d entries\n",fname,
+            num_entries_copied));
+
+  return num_entries_copied;
+}
+
+/*******************************************************************
+del a share mode from a share mode file.
+********************************************************************/
+static void slow_del_share_mode(int token, int fnum)
+{
+  pstring fname;
+  int fd = (int)token;
+  char *buf = 0;
+  char *base = 0;
+  int num_entries;
+  int newsize;
+  int i;
+  files_struct *fs_p = &Files[fnum];
+  int pid;
+  BOOL deleted = False;
+  BOOL new_file;
+
+  share_name(fs_p->cnum, fs_p->fd_ptr->dev, 
+                       fs_p->fd_ptr->inode, fname);
+
+  if(read_share_file( fs_p->cnum, fd, fname, &buf, &new_file) != 0)
+  {
+    DEBUG(0,("ERROR: del_share_mode: Failed to read share file %s\n",
+                  fname));
+    return;
+  }
+
+  if(new_file == True)
+  {
+    DEBUG(0,("ERROR:del_share_mode: share file %s is new (size zero), deleting it.\n",
+              fname));
+    delete_share_file(fs_p->cnum, fname);
+    return;
+  }
+
+  num_entries = IVAL(buf,SMF_NUM_ENTRIES_OFFSET);
+
+  DEBUG(5,("del_share_mode: share file %s has %d share mode entries.\n",
+            fname, num_entries));
+
+  /* PARANOIA TEST */
+  if(num_entries < 0)
+  {
+    DEBUG(0,("PANIC ERROR:del_share_mode: num_share_mode_entries < 0 (%d) \
+for share file %d\n", num_entries, fname));
+    return;
+  }
+
+  if(num_entries == 0)
+  {
+    /* No entries - just delete the file. */
+    DEBUG(0,("del_share_mode: share file %s has no share mode entries - deleting.\n",
+              fname));
+    if(buf)
+      free(buf);
+    delete_share_file(fs_p->cnum, fname);
+    return;
+  }
+
+  pid = getpid();
+
+  /* Go through the entries looking for the particular one
+     we have set - delete it.
+  */
+
+  base = buf + SMF_HEADER_LENGTH + SVAL(buf,SMF_FILENAME_LEN_OFFSET);
+
+  for(i = 0; i < num_entries; i++)
+  {
+    char *p = base + (i*SMF_ENTRY_LENGTH);
+
+    if((IVAL(p,SME_SEC_OFFSET) != fs_p->open_time.tv_sec) || 
+       (IVAL(p,SME_USEC_OFFSET) != fs_p->open_time.tv_usec) ||
+       (IVAL(p,SME_SHAREMODE_OFFSET) != fs_p->share_mode) || 
+       (IVAL(p,SME_PID_OFFSET) != pid))
+      continue;
+
+    DEBUG(5,("del_share_mode: deleting entry number %d (of %d) from the share file %s\n",
+             i, num_entries, fname));
+
+    /* Remove this entry. */
+    if(i != num_entries - 1)
+      memcpy(p, p + SMF_ENTRY_LENGTH, (num_entries - i - 1)*SMF_ENTRY_LENGTH);
+
+    deleted = True;
+    break;
+  }
+
+  if(!deleted)
+  {
+    DEBUG(0,("del_share_mode: entry not found in share file %s\n", fname));
+    if(buf)
+      free(buf);
+    return;
+  }
+
+  num_entries--;
+  SIVAL(buf,SMF_NUM_ENTRIES_OFFSET, num_entries);
+
+  if(num_entries == 0)
+  {
+    /* Deleted the last entry - remove the file. */
+    DEBUG(5,("del_share_mode: removed last entry in share file - deleting share file %s\n",
+             fname));
+    if(buf)
+      free(buf);
+    delete_share_file(fs_p->cnum,fname);
+    return;
+  }
+
+  /* Re-write the file - and truncate it at the correct point. */
+  if(lseek(fd, 0, SEEK_SET) != 0)
+  {
+    DEBUG(0,("ERROR: del_share_mode: lseek failed to reset to \
+position 0 for share mode file %s (%s)\n", fname, strerror(errno)));
+    if(buf)
+      free(buf);
+    return;
+  }
+
+  newsize = (base - buf) + (SMF_ENTRY_LENGTH*num_entries);
+  if(write(fd, buf, newsize) != newsize)
+  {
+    DEBUG(0,("ERROR: del_share_mode: failed to re-write share \
+mode file %s (%s)\n", fname, strerror(errno)));
+    if(buf)
+      free(buf);
+    return;
+  }
+  /* Now truncate the file at this point. */
+  if(ftruncate(fd, newsize) != 0)
+  {
+    DEBUG(0,("ERROR: del_share_mode: failed to ftruncate share \
+mode file %s to size %d (%s)\n", fname, newsize, strerror(errno)));
+    if(buf)
+      free(buf);
+    return;
+  }
+}
+  
+/*******************************************************************
+set the share mode of a file
+********************************************************************/
+static BOOL slow_set_share_mode(int token,int fnum, uint16 port, uint16 op_type)
+{
+  files_struct *fs_p = &Files[fnum];
+  pstring fname;
+  int fd = (int)token;
+  int pid = (int)getpid();
+  struct stat sb;
+  char *buf;
+  int num_entries;
+  int header_size;
+  char *p;
+
+  share_name(fs_p->cnum, fs_p->fd_ptr->dev,
+                       fs_p->fd_ptr->inode, fname);
+
+  if(fstat(fd, &sb) != 0)
+  {
+    DEBUG(0,("ERROR: set_share_mode: Failed to do stat on share file %s\n",
+                  fname));
+    return False;
+  }
+
+  /* Sanity check for file contents (if it's not a new share file). */
+  if(sb.st_size != 0)
+  {
+    int size = sb.st_size;
+
+    /* Allocate space for the file plus one extra entry */
+    if((buf = (char *)malloc(sb.st_size + SMF_ENTRY_LENGTH)) == NULL)
+    {
+      DEBUG(0,("set_share_mode: malloc for file size %d fail !\n", 
+                  sb.st_size + SMF_ENTRY_LENGTH));
+      return False;
+    }
+ 
+    if(lseek(fd, 0, SEEK_SET) != 0)
+    {
+      DEBUG(0,("ERROR: set_share_mode: Failed to reset position \
+to 0 for share file %s (%s)\n", fname, strerror(errno)));
+      if(buf)
+        free(buf);
+      return False;
+    }
+
+    if (read(fd,buf,sb.st_size) != sb.st_size)
+    {
+      DEBUG(0,("ERROR: set_share_mode: Failed to read share file %s (%s)\n",
+                  fname, strerror(errno)));
+      if(buf)
+        free(buf);
+      return False;
+    }   
+  
+    if (IVAL(buf,SMF_VERSION_OFFSET) != LOCKING_VERSION) 
+    {
+      DEBUG(0,("ERROR: set_share_mode: share file %s has incorrect \
+locking version (was %d, should be %d).\n",fname, IVAL(buf,SMF_VERSION_OFFSET), 
+                    LOCKING_VERSION));
+      if(buf)
+        free(buf);
+      delete_share_file(fs_p->cnum, fname);
+      return False;
+    }   
+
+    size -= (SMF_HEADER_LENGTH + SVAL(buf, SMF_FILENAME_LEN_OFFSET)); /* Remove the header */
+
+    /* The remaining size must be a multiple of SMF_ENTRY_LENGTH - error if not. */
+    if((size % SMF_ENTRY_LENGTH) != 0)
+    {
+      DEBUG(0,("ERROR: set_share_mode: share file %s is an incorrect length - \
+deleting it.\n", fname));
+      if(buf)
+        free(buf);
+      delete_share_file(fs_p->cnum, fname);
+      return False;
+    }
+
+  }
+  else
+  {
+    /* New file - just use a single_entry. */
+    if((buf = (char *)malloc(SMF_HEADER_LENGTH + 
+                  strlen(fs_p->name) + 1 + SMF_ENTRY_LENGTH)) == NULL)
+    {
+      DEBUG(0,("ERROR: set_share_mode: malloc failed for single entry.\n"));
+      return False;
+    }
+    SIVAL(buf,SMF_VERSION_OFFSET,LOCKING_VERSION);
+    SIVAL(buf,SMF_NUM_ENTRIES_OFFSET,0);
+    SSVAL(buf,SMF_FILENAME_LEN_OFFSET,strlen(fs_p->name) + 1);
+    strcpy(buf + SMF_HEADER_LENGTH, fs_p->name);
+  }
+
+  num_entries = IVAL(buf,SMF_NUM_ENTRIES_OFFSET);
+  header_size = SMF_HEADER_LENGTH + SVAL(buf,SMF_FILENAME_LEN_OFFSET);
+  p = buf + header_size + (num_entries * SMF_ENTRY_LENGTH);
+  SIVAL(p,SME_SEC_OFFSET,fs_p->open_time.tv_sec);
+  SIVAL(p,SME_USEC_OFFSET,fs_p->open_time.tv_usec);
+  SIVAL(p,SME_SHAREMODE_OFFSET,fs_p->share_mode);
+  SIVAL(p,SME_PID_OFFSET,pid);
+  SSVAL(p,SME_PORT_OFFSET,port);
+  SSVAL(p,SME_OPLOCK_TYPE_OFFSET,op_type);
+
+  num_entries++;
+
+  SIVAL(buf,SMF_NUM_ENTRIES_OFFSET,num_entries);
+
+  if(lseek(fd, 0, SEEK_SET) != 0)
+  {
+    DEBUG(0,("ERROR: set_share_mode: (1) Failed to reset position to \
+0 for share file %s (%s)\n", fname, strerror(errno)));
+    if(buf)
+      free(buf);
+    return False;
+  }
+
+  if (write(fd,buf,header_size + (num_entries*SMF_ENTRY_LENGTH)) != 
+                       (header_size + (num_entries*SMF_ENTRY_LENGTH))) 
+  {
+    DEBUG(2,("ERROR: set_share_mode: Failed to write share file %s - \
+deleting it (%s).\n",fname, strerror(errno)));
+    delete_share_file(fs_p->cnum, fname);
+    if(buf)
+      free(buf);
+    return False;
+  }
+
+  /* Now truncate the file at this point - just for safety. */
+  if(ftruncate(fd, header_size + (SMF_ENTRY_LENGTH*num_entries))!= 0)
+  {
+    DEBUG(0,("ERROR: set_share_mode: failed to ftruncate share \
+mode file %s to size %d (%s)\n", fname, header_size + (SMF_ENTRY_LENGTH*num_entries), 
+                strerror(errno)));
+    if(buf)
+      free(buf);
+    return False;
+  }
+
+  if(buf)
+    free(buf);
+
+  DEBUG(3,("set_share_mode: Created share file %s with \
+mode 0x%X pid=%d\n",fname,fs_p->share_mode,pid));
+
+  return True;
+}
+
+/*******************************************************************
+Remove an oplock port and mode entry from a share mode.
+********************************************************************/
+static BOOL slow_remove_share_oplock(int fnum, int token)
+{
+  pstring fname;
+  int fd = (int)token;
+  char *buf = 0;
+  char *base = 0;
+  int num_entries;
+  int fsize;
+  int i;
+  files_struct *fs_p = &Files[fnum];
+  int pid;
+  BOOL found = False;
+  BOOL new_file;
+
+  share_name(fs_p->cnum, fs_p->fd_ptr->dev, 
+                       fs_p->fd_ptr->inode, fname);
+
+  if(read_share_file( fs_p->cnum, fd, fname, &buf, &new_file) != 0)
+  {
+    DEBUG(0,("ERROR: remove_share_oplock: Failed to read share file %s\n",
+                  fname));
+    return False;
+  }
+
+  if(new_file == True)
+  {
+    DEBUG(0,("ERROR: remove_share_oplock: share file %s is new (size zero), \
+deleting it.\n", fname));
+    delete_share_file(fs_p->cnum, fname);
+    return False;
+  }
+
+  num_entries = IVAL(buf,SMF_NUM_ENTRIES_OFFSET);
+
+  DEBUG(5,("remove_share_oplock: share file %s has %d share mode entries.\n",
+            fname, num_entries));
+
+  /* PARANOIA TEST */
+  if(num_entries < 0)
+  {
+    DEBUG(0,("PANIC ERROR:remove_share_oplock: num_share_mode_entries < 0 (%d) \
+for share file %d\n", num_entries, fname));
+    return False;
+  }
+
+  if(num_entries == 0)
+  {
+    /* No entries - just delete the file. */
+    DEBUG(0,("remove_share_oplock: share file %s has no share mode entries - deleting.\n",
+              fname));
+    if(buf)
+      free(buf);
+    delete_share_file(fs_p->cnum, fname);
+    return False;
+  }
+
+  pid = getpid();
+
+  /* Go through the entries looking for the particular one
+     we have set - remove the oplock settings on it.
+  */
+
+  base = buf + SMF_HEADER_LENGTH + SVAL(buf,SMF_FILENAME_LEN_OFFSET);
+
+  for(i = 0; i < num_entries; i++)
+  {
+    char *p = base + (i*SMF_ENTRY_LENGTH);
+
+    if((IVAL(p,SME_SEC_OFFSET) != fs_p->open_time.tv_sec) || 
+       (IVAL(p,SME_USEC_OFFSET) != fs_p->open_time.tv_usec) ||
+       (IVAL(p,SME_SHAREMODE_OFFSET) != fs_p->share_mode) || 
+       (IVAL(p,SME_PID_OFFSET) != pid))
+      continue;
+
+    DEBUG(5,("remove_share_oplock: clearing oplock on entry number %d (of %d) \
+from the share file %s\n", i, num_entries, fname));
+
+    SSVAL(p,SME_PORT_OFFSET,0);
+    SSVAL(p,SME_OPLOCK_TYPE_OFFSET,0);
+    found = True;
+    break;
+  }
+
+  if(!found)
+  {
+    DEBUG(0,("remove_share_oplock: entry not found in share file %s\n", fname));
+    if(buf)
+      free(buf);
+    return False;
+  }
+
+  /* Re-write the file - and truncate it at the correct point. */
+  if(lseek(fd, 0, SEEK_SET) != 0)
+  {
+    DEBUG(0,("ERROR: remove_share_oplock: lseek failed to reset to \
+position 0 for share mode file %s (%s)\n", fname, strerror(errno)));
+    if(buf)
+      free(buf);
+    return False;
+  }
+
+  fsize = (base - buf) + (SMF_ENTRY_LENGTH*num_entries);
+  if(write(fd, buf, fsize) != fsize)
+  {
+    DEBUG(0,("ERROR: remove_share_oplock: failed to re-write share \
+mode file %s (%s)\n", fname, strerror(errno)));
+    if(buf)
+      free(buf);
+    return False;
+  }
+
+  return True;
+}
+
+
+
+/*******************************************************************
+call the specified function on each entry under management by the
+share ode system
+********************************************************************/
+static int slow_share_forall(void (*fn)(share_mode_entry *, char *))
+{
+	int i, count=0;
+	void *dir;
+	char *s;
+	share_mode_entry e;
+
+	dir = opendir(lp_lockdir());
+	if (!dir) {
+		return(0);
+	}
+
+	while ((s=readdirname(dir))) {
+		char *buf;
+		char *base;
+		int fd;
+		pstring lname;
+		uint32 dev,inode;
+		BOOL new_file;
+		pstring fname;
+
+		if (sscanf(s,"share.%u.%u",&dev,&inode)!=2) continue;
+       
+		strcpy(lname,lp_lockdir());
+		trim_string(lname,NULL,"/");
+		strcat(lname,"/");
+		strcat(lname,s);
+       
+		fd = open(lname,O_RDWR,0);
+		if (fd < 0) {
+			continue;
+		}
+
+		/* Lock the share mode file while we read it. */
+		if(fcntl_lock(fd, F_SETLKW, 0, 1, F_WRLCK) == False) {
+			close(fd);
+			continue;
+		}
+
+		if(read_share_file( 0, fd, lname, &buf, &new_file)) {
+			close(fd);
+			continue;
+		} 
+		strcpy( fname, &buf[10]);
+		close(fd);
+      
+		base = buf + SMF_HEADER_LENGTH + 
+			SVAL(buf,SMF_FILENAME_LEN_OFFSET); 
+		for( i = 0; i < IVAL(buf, SMF_NUM_ENTRIES_OFFSET); i++) {
+			char *p = base + (i*SMF_ENTRY_LENGTH);
+			e.pid = IVAL(p,SME_PID_OFFSET);
+			e.share_mode = IVAL(p,SME_SHAREMODE_OFFSET);
+			e.time.tv_sec = IVAL(p,SME_SEC_OFFSET);
+			e.time.tv_usec = IVAL(p,SME_USEC_OFFSET);
+			e.op_port = SVAL(p,SME_PORT_OFFSET);
+			e.pid = SVAL(p,SME_PID_OFFSET);
+			e.op_type = SVAL(p,SME_OPLOCK_TYPE_OFFSET);
+
+			fn(&e, fname);
+			count++;
+		} /* end for i */
+
+		if(buf)
+			free(buf);
+		base = 0;
+	} /* end while */
+	closedir(dir);
+
+	return count;
+}
+
+
+/*******************************************************************
+dump the state of the system
+********************************************************************/
+static void slow_share_status(FILE *f)
+{
+	
+}
+
+
+static struct share_ops share_ops = {
+	slow_stop_share_mode_mgmt,
+	slow_lock_share_entry,
+	slow_unlock_share_entry,
+	slow_get_share_modes,
+	slow_del_share_mode,
+	slow_set_share_mode,
+	slow_remove_share_oplock,
+	slow_share_forall,
+	slow_share_status,
+};
+
+/*******************************************************************
+  initialize the slow share_mode management 
+  ******************************************************************/
+struct share_ops *locking_slow_init(void)
+{
+	if (!directory_exist(lp_lockdir(),NULL)) {
+		mkdir(lp_lockdir(),0755);
+		if (!directory_exist(lp_lockdir(),NULL))
+			return NULL;
+	}
+
+	return &share_ops;
+}