ceph: set up readahead size when rsize is not passed

This should improve the default read performance, as without it
readahead is practically disabled.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index d4757c98ec14..d47c5ec7fb1f 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -779,6 +779,10 @@ static int ceph_register_bdi(struct super_block *sb,
                 fsc->backing_dev_info.ra_pages =
                         (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1)
                         >> PAGE_SHIFT;
+        else
+                fsc->backing_dev_info.ra_pages =
+                        default_backing_dev_info.ra_pages;
+
         err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%d",
                            atomic_long_inc_return(&bdi_seq));
         if (!err)