[mythtv] [PATCH] fix calculation of free disk space

[Marc Slemko]

in a struct statfs, there are two fields related to free blocks:

         long    f_bfree;    /* free blocks in fs */
         long    f_bavail;   /* free blocks avail to non-superuser */

currently, mythtv uses f_bfree everywhere.  Since mythtv should normally
not be running as root, this means its calculations are off, especially
with a large partition with the ext2fs default of 5% space reserved for
the superuser.  This is a bigger deal now that there is autoexpiration
code.

This patch just changes the calculations to use f_bavail instead, which is
the space actually available to a user.

Index: programs/mythbackend/autoexpire.cpp
===================================================================
RCS file: /var/lib/mythcvs/mythtv/programs/mythbackend/autoexpire.cpp,v
retrieving revision 1.3
diff -u -r1.3 autoexpire.cpp
--- programs/mythbackend/autoexpire.cpp	17 Jul 2003 01:04:13 -0000	1.3
+++ programs/mythbackend/autoexpire.cpp	17 Aug 2003 19:17:38 -0000
@@ -57,7 +57,7 @@
         struct statfs statbuf;
         int freespace = -1;
         if (statfs(recordfileprefix.ascii(), &statbuf) == 0) {
-            freespace = statbuf.f_bfree / (1024*1024*1024/statbuf.f_bsize);
+            freespace = statbuf.f_bavail / (1024*1024*1024/statbuf.f_bsize);
         }

         int minFree = gContext->GetNumSetting("AutoExpireDiskThreshold", 0);
@@ -95,7 +95,7 @@
                 if (statfs(recordfileprefix.ascii(), &statbuf) == 0)
                 {
                     freespace =
-                        statbuf.f_bfree / (1024*1024*1024/statbuf.f_bsize);
+                        statbuf.f_bavail / (1024*1024*1024/statbuf.f_bsize);
                 }
             }

Index: programs/mythbackend/encoderlink.cpp
===================================================================
RCS file: /var/lib/mythcvs/mythtv/programs/mythbackend/encoderlink.cpp,v
retrieving revision 1.24
diff -u -r1.24 encoderlink.cpp
--- programs/mythbackend/encoderlink.cpp	7 Aug 2003 21:23:59 -0000	1.24
+++ programs/mythbackend/encoderlink.cpp	17 Aug 2003 19:17:39 -0000
@@ -172,7 +172,7 @@
         struct statfs statbuf;
         if (statfs(recordfileprefix.ascii(), &statbuf) == 0)
         {
-            freeSpace = statbuf.f_bfree / (1024*1024/statbuf.f_bsize);
+            freeSpace = statbuf.f_bavail / (1024*1024/statbuf.f_bsize);
         }
     }
     else if (sock)
@@ -191,7 +191,7 @@
             struct statfs statbuf;
             if (statfs(recordfileprefix.ascii(), &statbuf) == 0)
             {
-                freeSpace = statbuf.f_bfree / (1024*1024/statbuf.f_bsize);
+                freeSpace = statbuf.f_bavail / (1024*1024/statbuf.f_bsize);
             }
         }
     }
Index: programs/mythbackend/mainserver.cpp
===================================================================
RCS file: /var/lib/mythcvs/mythtv/programs/mythbackend/mainserver.cpp,v
retrieving revision 1.73
diff -u -r1.73 mainserver.cpp
--- programs/mythbackend/mainserver.cpp	11 Aug 2003 20:44:38 -0000	1.73
+++ programs/mythbackend/mainserver.cpp	17 Aug 2003 19:17:46 -0000
@@ -912,8 +912,10 @@
     int totalspace = -1, usedspace = -1;
     if (statfs(recordfileprefix.ascii(), &statbuf) == 0)
     {
-        totalspace = statbuf.f_blocks / (1024*1024/statbuf.f_bsize);
-        usedspace = (statbuf.f_blocks - statbuf.f_bfree) /
+	// total space available to user is total blocks - reserved blocks
+        totalspace = (statbuf.f_blocks - (statbuf.f_bfree - statbuf.f_bavail)) /
+		    (1024*1024/statbuf.f_bsize);
+        usedspace = (statbuf.f_blocks - statbuf.f_bavail) /
                     (1024*1024/statbuf.f_bsize);
     }