mds: don't renew revoking lease

MDS may receives lease renew request while lease is being revoked,
just ignore the renew request.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fix Locker::simple_eval()

Locker::simple_eval() checks if the loner wants CEPH_CAP_GEXCL to
decide if it should change the lock to EXCL state, but it checks
if CEPH_CAP_GEXCL is issued to the loner to decide if it should
change the lock to SYNC state. So if the loner wants CEPH_CAP_GEXCL,
but doesn't have CEPH_CAP_GEXCL, Locker::simple_eval() will keep
switching the lock state.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: don't trigger assertion when discover races with rename

Discover reply that adds replica dentry and inode can race with rename
if slave request for rename sends discover and waits, but waked up by
reply for different discover.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: xlock stray dentry when handling rename or unlink

This prevents MDS from reintegrating stray before rename/unlink finishes

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: don't journal null dentry for overwrited remote linkage

Server::_rename_prepare() adds null dest dentry to the EMetaBlob if
the rename operation overwrites a remote linkage. This is incorrect
because null dentry are processed after primary and remote dentries
during journal replay. The erroneous null dentry makes the dentry of
rename destination disappear.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: use null dentry to find old parent of renamed directory

When replaying an directory rename operation, MDS need to find old parent of
the renamed directory to adjust auth subtree. Current code searchs the cache
to find the old parent, it does not work if the renamed directory inode is not
in the cache. EMetaBlob for directory rename contains at most one null dentry,
so MDS can use null dentry to find old parent of the renamed directory. If
there is no null dentry in the EMetaBlob, the MDS was witness of the rename
operation and there is not auth subtree underneath the renamed directory.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: don't trim ambiguous imports in MDCache::trim_non_auth_subtree

Trimming ambiguous imports in MDCache::trim_non_auth_subtree() confuses
MDCache::disambiguate_imports() and causes infinite loop.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: only export directory fragments in stray to their auth MDS

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: mark rename inode as ambiguous auth on all involved MDS

When handling cross authority rename, the master first sends OP_RENAMEPREP
slave requests to witness MDS, then sends OP_RENAMEPREP slave request to
the rename inode's auth MDS after getting all witness MDS' acknowledgments.
Before receiving the OP_RENAMEPREP slave request, the rename inode's auth
MDS may change lock state of the rename inode and send lock messages to
witness MDS. But the witness MDS may already received the OP_RENAMEPREP
slave request and changed the source inode's authority. So the witness MDS
send lock acknowledgment message to wrong MDS and trigger assertion.

The fix is, firstly the master marks rename inode as ambiguous and send a
message to ask the rename inode's auth MDS to mark the inode as ambiguous,
then send OP_RENAMEPREP slave requests to the witness MDS, finally send
OP_RENAMEPREP slave request to the rename inode's auth MDS after getting
all witness MDS' acknowledgments.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: skip frozen inode when assimilating dirty inodes' rstat

CDir::assimilate_dirty_rstat_inodes() may encounter frozen inodes that
are being renamed. Skip these frozen inodes because assimilating inode's
rstat require auth pinning the inode.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fix anchor table commit race

Anchor table updates for a given inode is fully serialized on client side.
But due to network latency, two commit requests from different clients can
arrive to anchor server out of order. The anchor table gets corrupted if
updates are committed in wrong order.

The fix is track on-going anchor updates for individual inode and delay
processing commit requests that arrive out of order.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fix on-going two phrase commits tracking

The slaves for two phrase commit should be mdr->more()->witnessed
instead of mdr->more()->slaves. mdr->more()->slaves includes MDS
for remote auth pin and lock

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: indroduce DROPLOCKS slave request

In some rare case, Locker::acquire_locks() drops all acquired locks
in order to auth pin new objects. But Locker::drop_locks only drops
explicitly acquired remote locks, does not drop objects' version
locks that were implicitly acquired on remote MDS. These leftover
locks break locking order when re-acquiring _locks and may cause
dead lock.

The fix is indroduce DROPLOCKS slave request which drops all acquired
lock on remote MDS.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: fix lock state transition check

Locker::simple_excl() and Locker::scatter_mix() miss is_rdlocked
check; Locker::file_excl() miss is_rdlocked check and is_wrlocked
check.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: remove unnecessary is_xlocked check

Locker::foo_eval() is always called for stable locks, so no need to
check if the lock is xlocked.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: don't defer processing caps if inode is auth pinned

We should not defer processing caps if the inode is auth pinned by MDRequest,
because the MDRequest may change lock state of the inode later and wait for
the deferred caps.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: call maybe_eval_stray after removing a replica dentry

MDCache::handle_cache_expire() processes dentries after inodes, so the
MDCache::maybe_eval_stray() in MDCache::inode_remove_replica() always
fails to remove stray inode because MDCache::eval_stray() checks if the
stray inode's dentry is replicated.

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

Use "srcdn->is_auth() && destdnl->is_primary()" to check if the MDS is
inode exportor of rename operation is not reliable, This is because
OP_FINISH slave request may race with subtree import. The fix is use
a variable in MDRequest to indicate if the MDS is inode exportor.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: disable concurrent remote locking

Current code allows multiple MDRequests to concurrently acquire a
remote lock. But a lock ACK message wakes all requests because they
were all put to the same waiting queue. One request gets the lock,
the rest requests will re-send the OP_WRLOCK/OPWRLOCK slave requests
and trigger assertion on remote MDS. The fix is disable concurrently
acquiring remote lock, send OP_WRLOCK/OPWRLOCK slave request only
if there is no on-going slave request.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mds: forbid creating file in deleted directory

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