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diff --git a/docs/htmldocs/oplocks.html b/docs/htmldocs/oplocks.html deleted file mode 100644 index 6aa91fb17f..0000000000 --- a/docs/htmldocs/oplocks.html +++ /dev/null @@ -1,208 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<HTML -><HEAD -><TITLE ->Oplocks</TITLE -><META -NAME="GENERATOR" -CONTENT="Modular DocBook HTML Stylesheet Version 1.77"><LINK -REL="HOME" -TITLE="SAMBA Project Documentation" -HREF="samba-howto-collection.html"><LINK -REL="UP" -TITLE="General installation" -HREF="introduction.html"><LINK -REL="PREVIOUS" -TITLE="Improved browsing in samba" -HREF="improved-browsing.html"><LINK -REL="NEXT" -TITLE="Quick Cross Subnet Browsing / Cross Workgroup Browsing guide" -HREF="browsing-quick.html"></HEAD -><BODY -CLASS="CHAPTER" -BGCOLOR="#FFFFFF" -TEXT="#000000" -LINK="#0000FF" -VLINK="#840084" -ALINK="#0000FF" -><DIV -CLASS="NAVHEADER" -><TABLE -SUMMARY="Header navigation table" -WIDTH="100%" -BORDER="0" -CELLPADDING="0" -CELLSPACING="0" -><TR -><TH -COLSPAN="3" -ALIGN="center" ->SAMBA Project Documentation</TH -></TR -><TR -><TD -WIDTH="10%" -ALIGN="left" -VALIGN="bottom" -><A -HREF="improved-browsing.html" -ACCESSKEY="P" ->Prev</A -></TD -><TD -WIDTH="80%" -ALIGN="center" -VALIGN="bottom" -></TD -><TD -WIDTH="10%" -ALIGN="right" -VALIGN="bottom" -><A -HREF="browsing-quick.html" -ACCESSKEY="N" ->Next</A -></TD -></TR -></TABLE -><HR -ALIGN="LEFT" -WIDTH="100%"></DIV -><DIV -CLASS="CHAPTER" -><H1 -><A -NAME="OPLOCKS" -></A ->Chapter 3. Oplocks</H1 -><DIV -CLASS="SECT1" -><H1 -CLASS="SECT1" -><A -NAME="AEN378" -></A ->3.1. What are oplocks?</H1 -><P ->When a client opens a file it can request an "oplock" or file -lease. This is (to simplify a bit) a guarentee that no one else -has the file open simultaneously. It allows the client to not -send any updates on the file to the server, thus reducing a -network file access to local access (once the file is in -client cache). An "oplock break" is when the server sends -a request to the client to flush all its changes back to -the server, so the file is in a consistent state for other -opens to succeed. If a client fails to respond to this -asynchronous request then the file can be corrupted. Hence -the "turn off oplocks" answer if people are having multi-user -file access problems.</P -><P ->Unless the kernel is "oplock aware" (SGI IRIX and Linux are -the only two UNIXes that are at the moment) then if a local -UNIX process accesses the file simultaneously then Samba -has no way of telling this is occuring, so the guarentee -to the client is broken. This can corrupt the file. Short -answer - it you have UNIX clients accessing the same file -as smbd locally or via NFS and you're not running Linux or -IRIX then turn off oplocks for that file or share.</P -><P ->"Share modes". These are modes of opening a file, that -guarentee an invarient - such as DENY_WRITE - which means -that if any other opens are requested with write access after -this current open has succeeded then they should be denied -with a "sharing violation" error message. Samba handles these -internally inside smbd. UNIX clients accessing the same file -ignore these invarients. Just proving that if you need simultaneous -file access from a Windows and UNIX client you *must* have an -application that is written to lock records correctly on both -sides. Few applications are written like this, and even fewer -are cross platform (UNIX and Windows) so in practice this isn't -much of a problem.</P -><P ->"Locking". This really means "byte range locking" - such as -lock 10 bytes at file offset 24 for write access. This is the -area in which well written UNIX and Windows apps will cooperate. -Windows locks (at least from NT or above) are 64-bit unsigned -offsets. UNIX locks are either 31 bit or 63 bit and are signed -(the top bit is used for the sign). Samba handles these by -first ensuring that all the Windows locks don't conflict (ie. -if other Windows clients have competing locks then just reject -immediately) - this allows us to support 64-bit Windows locks -on 32-bit filesystems. Secondly any locks that are valid are -then mapped onto UNIX fcntl byte range locks. These are the -locks that will be seen by UNIX processes. If there is a conflict -here the lock is rejected.</P -><P ->Note that if a client has an oplock then it "knows" that no -other client can have the file open so usually doesn't bother -to send to lock request to the server - this means once again -if you need to share files between UNIX and Windows processes -either use IRIX or Linux, or turn off oplocks for these -files/shares.</P -></DIV -></DIV -><DIV -CLASS="NAVFOOTER" -><HR -ALIGN="LEFT" -WIDTH="100%"><TABLE -SUMMARY="Footer navigation table" -WIDTH="100%" -BORDER="0" -CELLPADDING="0" -CELLSPACING="0" -><TR -><TD -WIDTH="33%" -ALIGN="left" -VALIGN="top" -><A -HREF="improved-browsing.html" -ACCESSKEY="P" ->Prev</A -></TD -><TD -WIDTH="34%" -ALIGN="center" -VALIGN="top" -><A -HREF="samba-howto-collection.html" -ACCESSKEY="H" ->Home</A -></TD -><TD -WIDTH="33%" -ALIGN="right" -VALIGN="top" -><A -HREF="browsing-quick.html" -ACCESSKEY="N" ->Next</A -></TD -></TR -><TR -><TD -WIDTH="33%" -ALIGN="left" -VALIGN="top" ->Improved browsing in samba</TD -><TD -WIDTH="34%" -ALIGN="center" -VALIGN="top" -><A -HREF="introduction.html" -ACCESSKEY="U" ->Up</A -></TD -><TD -WIDTH="33%" -ALIGN="right" -VALIGN="top" ->Quick Cross Subnet Browsing / Cross Workgroup Browsing guide</TD -></TR -></TABLE -></DIV -></BODY -></HTML ->
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