ceph: make seeky readdir more efficient
Current cephfs client uses string to indicate start position of
readdir. The string is last entry of previous readdir reply.
This approach does not work for seeky readdir because we can
not easily convert the new postion to a string. For seeky readdir,
mds needs to return dentries from the beginning. Client keeps
retrying if the reply does not contain the dentry it wants.
In current version of ceph, mds sorts CDentry in its cache in
hash order. Client also uses dentry hash to compose dir postion.
For seeky readdir, if client passes the hash part of dir postion
to mds. mds can avoid replying useless dentries.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index bbebcd5..3e67dd2 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -83,9 +83,10 @@ struct ceph_mds_reply_info_parsed {
struct ceph_mds_reply_dirfrag *dir_dir;
size_t dir_buf_size;
int dir_nr;
- bool dir_complete;
bool dir_end;
+ bool dir_complete;
bool hash_order;
+ bool offset_hash;
struct ceph_mds_reply_dir_entry *dir_entries;
};