From: Ben Hutchings <ben@decadent.org.uk>
Date: Thu, 28 Aug 2014 18:45:08 +0000 (-0700)
Subject: Add file-private locking slide
X-Git-Tag: debconf2014~5
X-Git-Url: https://git.decadent.org.uk/gitweb/?p=kernel-news-talk.git;a=commitdiff_plain;h=6cfa6de23f7b30ab3babf15904a786cf5f1e6c63

Add file-private locking slide
---

diff --git a/index.html b/index.html
index 12c844c..b3cc844 100644
--- a/index.html
+++ b/index.html
@@ -353,6 +353,33 @@
   </ul>
 </div>
 
+<div class="slide">
+  <h1>File-private locking [3.15]</h1>
+  <ul class="incremental">
+    <li>
+      POSIX says that closing a file descriptor removes
+      the <em>process</em>'s locks on that file
+    </li>
+    <li>
+      What if process has multiple file descriptors for the same
+      file?  It loses all locks obtained through any descriptor!
+    </li>
+    <li>
+      Multithreaded processes may require serialisation around
+      file open/close to ensure they open each file exactly once
+    </li>
+    <li>
+      Hard and symbolic links can hide that two files are really the
+      same
+    </li>
+    <li>
+      Linux now provides file-private locks, associated with a
+      specific open file and removed when last descriptor for the
+      open file is closed
+    </li>
+  </ul>
+</div>
+
 <div class="slide">
   <h1>Questions?</h1>
 </div>