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, 13 insertions, 0 deletions

diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 360e1443..3a620ac7 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -4604,6 +4604,15 @@ init (xlator_t *this_xl)
 	GF_OPTION_INIT("fopen-keep-cache", priv->fopen_keep_cache, bool,
 		cleanup_exit);
 
+	GF_OPTION_INIT("gid-timeout", priv->gid_cache_timeout, int32,
+		cleanup_exit);
+
+	if (gid_cache_init(&priv->gid_cache, priv->gid_cache_timeout) < 0) {
+		gf_log("glusterfs-fuse", GF_LOG_ERROR, "Failed to initialize "
+			"group cache.");
+		goto cleanup_exit;
+	}
+
         cmd_args = &this_xl->ctx->cmd_args;
         fsname = cmd_args->volfile;
         if (!fsname && cmd_args->volfile_server) {
@@ -4768,5 +4777,9 @@ struct volume_options options[] = {
 	  .type = GF_OPTION_TYPE_BOOL,
 	  .default_value = "false"
 	},
+	{ .key = {"gid-timeout"},
+	  .type = GF_OPTION_TYPE_INT,
+	  .default_value = "0"
+	},
         { .key = {NULL} },
 };