FOPEN_PASSTHROUGH
(FOPEN_PASSTHROUGH | FOPEN_DIRECT_IO | FOPEN_PARALLEL_DIRECT_WRITES | \
if (fuse_inode_backing(fi) && !(ff->open_flags & FOPEN_PASSTHROUGH))
!(ff->open_flags & FOPEN_PASSTHROUGH))
if (ff->open_flags & FOPEN_PASSTHROUGH)