diff options
| author | Yan, Zheng <zyan@redhat.com> | 2016-04-29 11:27:30 +0800 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2016-05-26 01:15:36 +0200 |
| commit | f3c4ebe65ea149ec892f94474233cfebe9cbe299 (patch) | |
| tree | 4a6aa1280fa6160d55935577792cd5d46e18f665 /include/linux | |
| parent | 076c40f18d10489e29c515bf5936952830df5e16 (diff) | |
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>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/ceph/ceph_fs.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h index a811c5e98bfa..dfce616002ad 100644 --- a/include/linux/ceph/ceph_fs.h +++ b/include/linux/ceph/ceph_fs.h @@ -357,6 +357,7 @@ extern const char *ceph_mds_op_name(int op); */ #define CEPH_READDIR_FRAG_END (1<<0) #define CEPH_READDIR_FRAG_COMPLETE (1<<8) +#define CEPH_READDIR_HASH_ORDER (1<<9) union ceph_mds_request_args { struct { |