client: implement RDCACHE reference tracking

make the code be able to track Fc caps used by aysnc buffer reads

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
client: hold Fcr caps during readahead

Fcr caps prevent the file from being truncated.

Fixes: #7958
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
client: assign implemented caps to caps field of MClientCaps

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
client: properly retain used caps

Pass properly 'retain' to Client::send_cap() because it is used to
adjust cap->issued.

Also make Client::encode_inode_release() not release used/dirty caps.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
client: drop Fr cap before gettattr CEPH_STAT_CAP_SIZE

When MDS receives the getattr request, corresponding inode's filelock
can be in unstable state which waits for client's Fr cap.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
client: cleanup Client::_invalidate_inode_cache()

drop parameter 'keep_caps'

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
ObjectCacher: assert no waiter when remove buffer head

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
client: fix null pointer dereference in Client::unlink

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
include/memory: add static_pointer_cast

Signed-off-by: Greg Farnum <greg@inktank.com>
mds: MDRequest: rename to MDRequestImpl, and declare MDRequestRef

We're switching the MDRequest to be used as a shared pointer. This is the
first step on the path to inserting an OpTracker into the MDS.
Give the MDRequestImpl a weak_ptr self_ref so that we can keep
using the elist for now.

Signed-off-by: Greg Farnum <greg@inktank.com>
MDS: Convert the request_start* functions and their immediate callers

Also, the active_requests mapping gets weak pointers.

Signed-off-by: Greg Farnum <greg@inktank.com>
Server: Use MDRequestRef instead of raw pointers

Signed-off-by: Greg Farnum <greg@inktank.com>
MDCache: use MDRequestRef instead of MDRequest*

Signed-off-by: Greg Farnum <greg@inktank.com>
Locker: use MDRequestRef instead of MDRequest*

Signed-off-by: Greg Farnum <greg@inktank.com>
Mutation: rename to MutationImpl and define MutationRef

Signed-off-by: Greg Farnum <greg@inktank.com>
Mutation: move self_ref into MutationImpl instead of MDRequestImpl

We keep an MDRequestImpl::set_self_ref(MDRequestRef&) function so
that we don't need to do the pointer conversion elsewhere.

Signed-off-by: Greg Farnum <greg@inktank.com>
SimpleLock: use MutationRef instead of raw pointers

While we're here, remove the non-const get_xlock_by() (because
we don't need it). Also note we return a full MutationRef
(instead of a ref to the stored one). It's necessary in case we
don't have a set-up more() object.

Signed-off-by: Greg Farnum <greg@inktank.com>
Migrator: use MDRequestRef and MutationRef instead of raw pointers

Signed-off-by: Greg Farnum <greg@inktank.com>
Migrator: use a null ref instead of NULL when calling into path_traverse

Signed-off-by: Greg Farnum <greg@inktank.com>
client: release clean pages if no open file want RDCACHE

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