libglusterfs,mount/fuse: implement gidcache mechanism in fuse-bridge

This change genericizes the cache mechanism implemented in commit
8efd2845 into libglusterfs/src/gidcache.[ch] and adds fuse-bridge as
a client. The cache mechanism is fundamentally equivalent, with some
minor changes:

  - Change cache key from uid_t to uint64_t.
  - Modify the cache add logic to locate and use an entry with a
    matching ID, should it already exist. This addresses a bug in
    the existing mechanism where an expired entry supercedes a newly
    added entry in lookup, causing repeated adds and flushing of a
    cache bucket.

The fuse group cache is disabled by default. It can be enabled via
the 'gid-timeout' fuse-bridge translator option and accompanying
mount option (i.e., '-o gid-timeout=1' for a 1s entry timeout).

BUG: 800892
Change-Id: I0b34a2263ca48dbb154790a4a44fc70b733e9114
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.com/3676
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/xlators/mount/fuse/src/fuse-bridge.h b/xlators/mount/fuse/src/fuse-bridge.h
index dcd9629246c..bc35eb0617d 100644
--- a/xlators/mount/fuse/src/fuse-bridge.h
+++ b/xlators/mount/fuse/src/fuse-bridge.h
@@ -55,6 +55,7 @@
 #include "list.h"
 #include "dict.h"
 #include "syncop.h"
+#include "gidcache.h"
 
 #if defined(GF_LINUX_HOST_OS) || defined(__NetBSD__)
 #define FUSE_OP_HIGH (FUSE_POLL + 1)
@@ -110,7 +111,9 @@ struct fuse_private {
         gf_boolean_t         selinux;
         gf_boolean_t         read_only;
 	gf_boolean_t	     fopen_keep_cache;
+	int32_t		     gid_cache_timeout;
         fdtable_t           *fdtable;
+	gid_cache_t	     gid_cache;
 
         /* For fuse-reverse-validation */
         int                  revchan_in;