[SCM] Samba Shared Repository - branch master updated - release-4-0-0alpha7-1011-g3c10d06

[Volker Lendecke]

The branch, master has been updated
       via  3c10d065247c94ceb721b102402bc6c4aeefe33d (commit)
      from  602059a6ab8c4939dd453566415321b2b85706f4 (commit)

http://gitweb.samba.org/?p=samba.git;a=shortlog;h=master


- Log -----------------------------------------------------------------
commit 3c10d065247c94ceb721b102402bc6c4aeefe33d
Author: Volker Lendecke <vl at samba.org>
Date:   Wed Apr 8 08:29:23 2009 +0200

    We have to deny a level 2 oplock if kernel oplocks are enabled
    
    The second r/o opener of a file is supposed to get a level2 oplock. The first
    opener due to the protection in process_oplock_break_message() has been forced
    to break to no oplock. The second opener according to locking.tdb gets a level2
    oplock. Further down in open_file_ntcreate we try to set this level2 oplock in
    the kernel, and the non-clustered Linux kernel disallows this. The rules for
    the kernel leases are a bit baroque, but the attempt to do the SETLEASE
    correctly fails and we end up with no oplock for any client.
    
    In the clustered case however the linux kernel on the second opening node has
    not seen the open fd of the first node, it is only the cluster fs that has this
    information. If the cluster fs does not have the very same notion of leases as
    the local kernel has, we can end up with a WRLCK style kernel lease for the
    second opener where locking.tdb only indicates a level2 oplock. Getting a
    kernel oplock break signal with just a level2 oplock in locking.tdb is
    something smbd is not prepared for. For example after sending out the break in
    response to the kernel signal we set a timeout, waiting for a reply.
    
    More work needs to be done to make level2 kernel oplocks real for us. This
    patch addresses a real problem we have right now without them.

-----------------------------------------------------------------------

Summary of changes:
 source3/smbd/oplock.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)


Changeset truncated at 500 lines:

diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c
index b937e8e..e9b2a6c 100644
--- a/source3/smbd/oplock.c
+++ b/source3/smbd/oplock.c
@@ -58,6 +58,12 @@ void break_kernel_oplock(struct messaging_context *msg_ctx, files_struct *fsp)
 
 bool set_file_oplock(files_struct *fsp, int oplock_type)
 {
+	if ((fsp->oplock_type == LEVEL_II_OPLOCK)
+	    && koplocks && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) {
+		DEBUG(10, ("Refusing level2 oplock, kernel oplocks don't "
+			   "support them\n"));
+		return false;
+	}
 	if ((fsp->oplock_type != NO_OPLOCK) &&
 	    (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
 	    koplocks &&


-- 
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