patch-2.1.4 linux/Documentation/locks.txt
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- Lines: 37
- Date:
Fri Oct 11 07:33:33 1996
- Orig file:
v2.1.3/linux/Documentation/locks.txt
- Orig date:
Sun Sep 22 09:41:32 1996
diff -u --recursive --new-file v2.1.3/linux/Documentation/locks.txt linux/Documentation/locks.txt
@@ -67,3 +67,36 @@
sendmail may have problems running in 'newaliases' mode. It will no longer
deadlock though. Recompile sendmail to use flock() and your troubles will
be over.
+
+1.3 Mandatory Locking As A Mount Option
+---------------------------------------
+
+Mandatory locking, as described in 'Documentation/mandatory.txt' was prior
+to this release a general configuration option that was valid for all
+mounted filesystems. This had a number of inherent dangers, not the least
+of which was the ability to freeze an NFS server by asking it to read a
+file for which a mandatory lock existed.
+
+From this release of the kernel, mandatory locking can be turned on and off
+on a per-filesystem basis, using the mount options 'mand' and 'nomand'.
+The default is to disallow mandatory locking. The intention is that
+mandatory locking only be enabled on a local filesystem as the specific need
+arises.
+
+Until an updated version of mount(8) becomes available you may have to apply
+this patch to the mount sources (based on the version distributed with Rick
+Faiths util-linux-2.5 package):
+
+*** mount.c.orig Sat Jun 8 09:14:31 1996
+--- mount.c Sat Jun 8 09:13:02 1996
+***************
+*** 100,105 ****
+--- 100,107 ----
+ { "noauto", 0, MS_NOAUTO }, /* Can only be mounted explicitly */
+ { "user", 0, MS_USER }, /* Allow ordinary user to mount */
+ { "nouser", 1, MS_USER }, /* Forbid ordinary user to mount */
++ { "mand", 0, MS_MANDLOCK }, /* Allow mandatory locks on this FS */
++ { "nomand", 1, MS_MANDLOCK }, /* Forbid mandatory locks on this FS */
+ /* add new options here */
+ #ifdef MS_NOSUB
+ { "sub", 1, MS_NOSUB }, /* allow submounts */
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