[LU-12665] moving files between MDTs by mv(1) doesn't work with Lustre-2.7 servers.

Related — Fri, 14 Aug 2020 12:26:09 +0000

Using 2.7 servers and 2.12 client:

[root@devvm1 tests]# ../utils/lctl set_param debug=-1; ../utils/lctl clear; mv /mnt/lustre/mdt1dir/foo /mnt/lustre/mdt0dir/ ; ../utils/lctl dk foo.log
debug=-1
mv: cannot move ‘/mnt/lustre/mdt1dir/foo’ to ‘/mnt/lustre/mdt0dir/foo’: Protocol error
Debug log: 3860 lines, 3860 kept, 0 dropped, 0 bad.
[root@devvm1 tests]#

It appears that -EPROTO(71) error is returned from mdt_object_lock_internal()

00000004:00000001:1.0:1565721044.423035:0:4601:0:(mdt_handler.c:2708:mdt_object_lock_internal()) Process leaving (rc=18446744073709551545 : -71 : ffffffffffffffb9)
00000004:00000001:1.0:1565721044.423036:0:4601:0:(mdt_reint.c:1788:mdt_rename_parents_lock()) Process leaving via err_tgt_put (rc=18446744073709551545 : -71 : 0xffffffffffffffb9)

the object is attempted to lock is the source dir.

It gives us the following:

Lustre 2.7 doesn't support cross-target renames but a rename rpc should return -EXDEV code .
EXDEV is returned to the client application. In case of mv(1), the utility fails back to a file copy, w/o informing
user that rename() syscall failed.

As I see, new clients (2.11, 2.12) are sending reint rename RPC to another MDT, i.e. to the target MDT. So the target dir becoming local and the request passes "target-is-remote" check in mdt_rename_lock_parents() , however the rename op fails later, attempting to lock source dir, which surprisedly is remote. Server sends -EPROTO to the client , the mv(1) just fails w/o failing back to file copy.

Whamcloud Community JIRA

[LU-12665] moving files between MDTs by mv(1) doesn't work with Lustre-2.7 servers.