mds: don't set xlocks on dentries done when early reply rename

_rename_finish() does not send dentry link/unlink message to replicas.
We should prevent dentries that are modified by the rename operation
from getting new replicas while the rename operation is committing.
So don't set xlocks on dentries "done".

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fix "had dentry linked to wrong inode" warning

The reason of "had dentry linked to wrong inode" warning is that
Server::_rename_prepare() adds the destdir to the EMetaBlob before
adding the straydir. So during MDS recovers, the destdir is first
replayed. The old inode is directly replaced by the source inode.
We can void the warning by adding the straydir first.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: splits rename force journal check into separate function

the function will be used by later patch that fixes rename rollback

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: force journal straydn for rename if necessary

rename may overwrite an empty directory inode and move it into stray
directory. MDS who has auth subtree beneath the overwrited directory
need journal the stray dentry when handling rename slave request.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: don't journal non-auth rename source directory

After replaying a slave rename, non-auth directory that we rename out of will
be trimmed. So there is no need to journal it.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: preserve non-auth/unlinked objects until slave commit

The MDS should not trim objects in non-auth subtree immediately after
replaying a slave rename. Because the slave rename may require rollback
later and these objects are needed for rollback.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fix slave rename rollback

The main issue of old slave rename rollback code is that it assumes
all affected objects are in the cache. The assumption is not true
when MDS does rollback in the resolve stage. This patch removes the
assumption and makes Server::do_rename_rollback() check individual
object and roll back change.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: split reslove into two sub-stages

The resolve stage serves to disambiguate the fate of uncommitted slave
updates and resolve subtrees authority. The MDS sends resolve message
that claims subtrees authority immediately when reslove stage is entered,
When receiving a resolve message, the MDS also processes it immediately.
This may cause problem if there are uncommitted slave rename and some of
them need rollback later. It's because slave rename rollback may modify
subtree map.

The fix is split reslove into two sub-stages, the first sub-stage serves
to disambiguate slave updates, do slave commit or rollback. After the
the first sub-stage finishes, the MDS sends resolve messages that claim
subtrees authority to other MDS and processes received resolve messages.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: send resolve messages after all MDS reach resolve stage

Current code sends resolve messages when resolving MDS set changes.
There is no need to send resolve messages when some MDS leave the
resolve stage. Sending message while some MDS are replaying is also
not very useful.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: always use {push,pop}_projected_linkage to change linkage

Current code skips using {push,pop}_projected_linkage to modify replica
dentry's linkage. This confuses EMetaBlob::add_dir_context() and makes
it record out-of-date path when TO_ROOT mode is used. This patch changes
the code to always use {push,pop}_projected_linkage to modify dentry's
linkage. It makes sure MDCache::create_subtree_map() record correct and
up-to-date subtree map.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: don't replace existing slave request

The MDS may receive a client request, but find there is an existing
slave request. It means other MDS is handling the same request, so
we should not replace the slave request with a new client request,
just forward the request.

The client request may include embeded cap releases, we need process
them even the request is forwarded.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fix for MDCache::adjust_bounded_subtree_auth

After swallowing extra subtrees, subtree bounds may change, so it
should re-check.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fix for MDCache::disambiguate_imports

In the resolve stage, if no MDS claims other MDS's disambiguous subtree
import, the subtree's dir_auth is undefined.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: journal inode's projected parent when doing link rollback

Otherwise the journal entry will revert the effect of any on-going
rename operation for the inode.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: don't journal opened non-auth inode

If we journal opened non-auth inode, during journal replay, the corresponding
entry will add non-auth objects to the cache. But the MDS does not journal all
subsequent modifications (rmdir,rename) to these non-auth objects, so the code
that manages cache and subtree may get confused. Besides non-auth objects will
be trimmed at the resolve stage.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: properly clear CDir::STATE_COMPLETE when replaying EImportStart

when replaying EImportStart, we should set/clear directory's COMPLETE
flag according with the flag in the journal entry.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: move variables special to rename into MDRequest::more

My previous patches add two pointers (ambiguous_auth_inode and
auth_pin_freeze) to class Mutation. They are both used by cross
authority rename, both point to the renamed inode. Later patches
need add more rename special state to MDRequest, So just move them
into MDRequest::more

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: rejoin remote wrlocks and frozen auth pin

Includes remote wrlocks and frozen authpin in cache rejoin strong message

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fetch missing inodes from disk

The problem of fetching missing inodes from replicas is that replicated inodes
does not have up-to-date rstat and fragstat. So just fetch missing inodes from
disk

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: add projected rename's subtree bounds to ESubtreeMap

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>