fuse: fuse: add time_gran to INIT_OUT
Allow userspace fs to specify time granularity.
This is needed because with writeback_cache mode the kernel is responsible
for generating mtime and ctime, but if the underlying filesystem doesn't
support nanosecond granularity then the cache will contain a different
value from the one stored on the filesystem resulting in a change of times
after a cache flush.
Make the default granularity 1s.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 5997e49..560eafc 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -891,6 +891,11 @@
fc->async_dio = 1;
if (arg->flags & FUSE_WRITEBACK_CACHE)
fc->writeback_cache = 1;
+ if (arg->time_gran && arg->time_gran <= 1000000000)
+ fc->sb->s_time_gran = arg->time_gran;
+ else
+ fc->sb->s_time_gran = 1000000000;
+
} else {
ra_pages = fc->max_read / PAGE_CACHE_SIZE;
fc->no_lock = 1;