Fixed paragraph about byte range locking. Jerry, could you make a pdf of this?

Thanks,

Volker
(This used to be commit 3811b6a9eba8c5567b4df01c86cc4fe33b0a8079)

1 files changed, 20 insertions, 15 deletions

diff --git a/docs/docbook/projdoc/UNIX_INSTALL.sgml b/docs/docbook/projdoc/UNIX_INSTALL.sgml
index 41eb7a478c..0e4d8a5d03 100644
--- a/docs/docbook/projdoc/UNIX_INSTALL.sgml
+++ b/docs/docbook/projdoc/UNIX_INSTALL.sgml
@@ -379,21 +379,26 @@
 		The second is the "deny modes" that are specified when a file 
 		is open.</para>
 
-		<para>Samba supports "record locking" using the fcntl() unix system
-		call. This is often implemented using rpc calls to a rpc.lockd process
-		running on the system that owns the filesystem. Unfortunately many
-		rpc.lockd implementations are very buggy, particularly when made to
-		talk to versions from other vendors. It is not uncommon for the
-		rpc.lockd to crash.</para>
-
-		<para>There is also a problem translating the 32 bit lock 
-		requests generated by PC clients to 31 bit requests supported 
-		by most unixes. Unfortunately many PC applications (typically 
-		OLE2 applications) use byte ranges with the top bit set 
-		as semaphore sets. Samba attempts translation to support 
-		these types of applications, and the translation has proved 
-		to be quite successful.</para>
-		
+		<para>Record locking semantics under Unix is very
+		different from record locking under Windows. Versions
+		of Samba before 2.2 have tried to use the native
+		fcntl() unix system call to implement proper record
+		locking between different Samba clients. This can not
+		be fully correct due to several reasons. The simplest
+		is the fact that a Windows client is allowed to lock a
+		byte range up to 2^32 or 2^64, depending on the client
+		OS. The unix locking only supports byte ranges up to
+		2^31. So it is not possible to correctly satisfy a
+		lock request above 2^31. There are many more
+		differences, too many to be listed here.</para>
+
+		<para>Samba 2.2 and above implements record locking
+		completely independent of the underlying unix
+		system. If a byte range lock that the client requests
+		happens to fall into the range 0-2^31, Samba hands
+		this request down to the Unix system. All other locks
+		can not be seen by unix anyway.</para>
+
 		<para>Strictly a SMB server should check for locks before 
 		every read and write call on a file. Unfortunately with the 
 		way fcntl() works this can be slow and may overstress the