fuse/md-cache: add support for the 'fopen-keep-cache' mount option

fopen-keep-cache disables unconditional page-cache invalidations
on file open in fuse (via FOPEN_KEEP_CACHE) and replaces that
behavior with detection of remote changes and explicit
invalidations from mount/fuse. This option improves local caching
through the page cache and native client.

This change defines a new 'invalidate' translator callback to
identify when an inode's cache mapping has been determined to be
invalid. md-cache implements the policy to detect and invoke
inode invalidations. fuse-bridge and io-cache implement
invalidate handlers to invalidate the respective caches (page
cache in the case of fuse).

BUG: 833564
Change-Id: I99818da5777eaf06276c1c0b194669f5bab92d48
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.com/3584
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/xlators/mount/fuse/utils/mount.glusterfs.in b/xlators/mount/fuse/utils/mount.glusterfs.in
index ee956885c4c..b623d3428b7 100755
--- a/xlators/mount/fuse/utils/mount.glusterfs.in
+++ b/xlators/mount/fuse/utils/mount.glusterfs.in
@@ -132,6 +132,10 @@ start_glusterfs ()
         cmd_line=$(echo "$cmd_line --entry-timeout=$entry_timeout");
     fi
 
+    if [ -n "$fopen_keep_cache" ]; then
+	cmd_line=$(echo "$cmd_line --fopen-keep-cache");
+    fi
+
     # for rdma volume, we have to fetch volfile with '.rdma' added
     # to volume name, so that it fetches the right client vol file
     volume_id_rdma="";
@@ -297,6 +301,7 @@ main ()
                     "acl")      acl=1 ;;
                     "selinux")  selinux=1 ;;
                     "worm")     worm=1 ;;
+		    "fopen-keep-cache")	fopen_keep_cache=1 ;;
                     # "mount -t glusterfs" sends this, but it's useless.
                     "rw")       ;;
                     *)