MDCache: add a scrub_dentry() function, and wire it up to the admin socket

scrub_dentry() is passed a string path, and it validates it before replying. We
hook up an admin socket command "scrub_path" to call it and dump the output.

Signed-off-by: Greg Farnum <greg@inktank.com>
Server: remove tracei and tracedn parameters from reply_request

We have members for these two parameters in the MDRequestImpl already, so
make use of them. This helps us move towards dropping the expectation of an
MClientRequest from functions like rdlock_path_pin_ref().

Signed-off-by: Greg Farnum <greg@inktank.com>
Server: do not use explicit MClientReply if we don't need to

Signed-off-by: Greg Farnum <greg@inktank.com>
Server: use mdr->reply_extra_bl instead of explicit MClientReply

Set the MClientReply::extra_bl from reply_extra_bl unconditionally in
reply_request(), instead of only in early_reply(). Further isolate
the reply_request() callers from the use of MClientReply this way.

Signed-off-by: Greg Farnum <greg@inktank.com>
Server: add snapbl to MDRequest and eliminate last explicit MClientReply

Signed-off-by: Greg Farnum <greg@inktank.com>
Server: rename reply_request -> reply_client_request; make it private

The generic reply_request(MDRequest, int) is now the only caller. It's still
just building an MClientRequest to pass along, but we can change it a lot more
easily now to support responding to non-client requests.

Signed-off-by: Greg Farnum <greg@inktank.com>
Server: rename reply_request() -> respond_to_request()

This is no longer necessarily a reply; it could turn into a Context
activation or something.

Signed-off-by: Greg Farnum <greg@inktank.com>
MDCache: "handle" request_forward on internal ops

For now, just return -EXDEV ("Cross-device link") on internal ops that
require forwarding, as forwarding internal ops will require a great deal more
infrastructure.. But push the issue down to this level instead of worrying
about it in path_traverse, and consider the possibility that the MDRequest
might not have a client_request that it's wrapped around.

Signed-off-by: Greg Farnum <greg@inktank.com>
MDCache: make scrub_dentry schedulable and reentrant

Rather than assuming that any necessary inodes are in the cache, split up
MDCache::scrub_dentry into setup and work phases. Add an internal_op_finisher()
to MDRequest. Dispatch any CEPH_MDS_OP_VALIDATE internal operations to
scrub_dentry_work(). Taken together, these make everything work properly when
path_traverse() (by way of rdlock_path_pin_ref()) needs to go to disk before
satisfying the lookup.

Signed-off-by: Greg Farnum <greg@inktank.com>
MDCache: handle internal ops in respond_to_request()

This only works for those which have specified a finisher in the MDR.

Signed-off-by: Greg Farnum <greg@inktank.com>
MDS: CInode: create a flush() function

Signed-off-by: Greg Farnum <greg@inktank.com>
MDS: add a flush_dentry() function, and wire it up to the admin socket

Signed-off-by: Greg Farnum <greg@inktank.com>
common/ceph_strings: add some MDS internal op names to ceph_mds_op_name()

In addition to my validate and flush, this is also missing exportdir.

Signed-off-by: Greg Farnum <greg@inktank.com>
MDS: CInode: break out of validation early on symlinks

Signed-off-by: Greg Farnum <gfarnum@redhat.com>
MDS: clean up internal MDRequests the standard way

All cleanup is now routed through respond_to_request(),
which invokes the internal_op_finish Context*, then does
mdcache->request_finish(). This is easier to reason about,
and indeed fixes a bug (I was not cleaning up locks
following flush). Use the MDSContinuation to facilitate
this in scrub's case.

Signed-off-by: Greg Farnum <gfarnum@redhat.com>
Merge remote-tracking branch 'origin/master' into wip-inode-scrub

Conflicts:
	src/common/Makefile.am
	src/mds/Server.cc

Signed-off-by: Greg Farnum <gfarnum@redhat.com>
doc: Added Dumpling to Firefly upgrade section.

Fixes: #7679

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
Merge pull request #2882 from ceph/wip-doc-dumpling-to-firefly

doc: Added Dumpling to Firefly upgrade section.
tools: error handling on journal import/export

Actually propagate nonzero returns codes!  Also
add checks on return values of I/O functions so
that someone doesn't think they've successfully
exported a journal if they haven't, and some
validation of the header pointers during import
so that people find out with a nice error
instead of an assertion if something is up.

Signed-off-by: John Spray <john.spray@redhat.com>

Fix compile issue in the position value cout.

Signed-off-by: Greg Farnum <gfarnum@redhat.com>
mailmap: Loic Dachary affiliation

Signed-off-by: Loic Dachary <ldachary@redhat.com>