ceph: using hash value to compose dentry offset
If MDS sorts dentries in dirfrag in hash order, we use hash value to
compose dentry offset. dentry offset is:
(0xff << 52) | ((24 bits hash) << 28) |
(the nth entry hash hash collision)
This offset is stable across directory fragmentation. This alos means
there is no need to reset readdir offset if directory get fragmented
in the middle of readdir.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 0628099..c9b671d 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -540,11 +540,6 @@
return (struct ceph_dentry_info *)dentry->d_fsdata;
}
-static inline loff_t ceph_make_fpos(unsigned frag, unsigned off)
-{
- return ((loff_t)frag << 32) | (loff_t)off;
-}
-
/*
* caps helpers
*/
@@ -949,6 +944,7 @@
extern const struct dentry_operations ceph_dentry_ops, ceph_snap_dentry_ops,
ceph_snapdir_dentry_ops;
+extern loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order);
extern int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry);
extern int ceph_handle_snapdir(struct ceph_mds_request *req,
struct dentry *dentry, int err);
