ceph: streamline request head structures in MDS client

The existence of the ceph_mds_request_head_old structure in the MDS
client code is no longer required due to improvements in handling
different MDS request header versions. This patch removes the now
redundant ceph_mds_request_head_old structure and replaces its usage
with the flexible and extensible ceph_mds_request_head structure.

Changes include:
- Modification of find_legacy_request_head to directly cast the
  pointer to ceph_mds_request_head_legacy without going through the
  old structure.
- Update sizeof calculations in create_request_message to use
  offsetofend for consistency and future-proofing, rather than
  referencing the old structure.
- Use of the structured ceph_mds_request_head directly instead of the
  old one.

Additionally, this consolidation normalizes the handling of
request_head_version v1 to align with versions v2 and v3, leading to
a more consistent and maintainable codebase.

These changes simplify the codebase and reduce potential confusion
stemming from the existence of an obsolete structure.

Signed-off-by: Liang Jie <liangjie@lixiang.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 0 insertions, 14 deletions

diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index 2d7d86f0290d..c7f2c63b3bc3 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -504,20 +504,6 @@ struct ceph_mds_request_head_legacy {
 
 #define CEPH_MDS_REQUEST_HEAD_VERSION  3
 
-struct ceph_mds_request_head_old {
-	__le16 version;                /* struct version */
-	__le64 oldest_client_tid;
-	__le32 mdsmap_epoch;           /* on client */
-	__le32 flags;                  /* CEPH_MDS_FLAG_* */
-	__u8 num_retry, num_fwd;       /* count retry, fwd attempts */
-	__le16 num_releases;           /* # include cap/lease release records */
-	__le32 op;                     /* mds op code */
-	__le32 caller_uid, caller_gid;
-	__le64 ino;                    /* use this ino for openc, mkdir, mknod,
-					  etc. (if replaying) */
-	union ceph_mds_request_args_ext args;
-} __attribute__ ((packed));
-
 struct ceph_mds_request_head {
 	__le16 version;                /* struct version */
 	__le64 oldest_client_tid;