linux-stable.git/drivers/block/rbd.c, branch v4.7

libceph: replace ceph_monc_request_next_osdmap()

2016-05-25T23:15:30+00:00

... with a wrapper around maybe_request_map() - no need for two
osdmap-specific functions.

Signed-off-by: Ilya Dryomov

libceph: async MON client generic requests

2016-05-25T23:15:29+00:00

For map check, we are going to need to send CEPH_MSG_MON_GET_VERSION
messages asynchronously and get a callback on completion.  Refactor MON
client to allow firing off generic requests asynchronously and add an
async variant of ceph_monc_get_version().  ceph_monc_do_statfs() is
switched over and remains sync.

Signed-off-by: Ilya Dryomov

libceph, rbd: ceph_osd_linger_request, watch/notify v2

2016-05-25T23:15:02+00:00

This adds support and switches rbd to a new, more reliable version of
watch/notify protocol.  As with the OSD client update, this is mostly
about getting the right structures linked into the right places so that
reconnects are properly sent when needed.  watch/notify v2 also
requires sending regular pings to the OSDs - send_linger_ping().

A major change from the old watch/notify implementation is the
introduction of ceph_osd_linger_request - linger requests no longer
piggy back on ceph_osd_request.  ceph_osd_event has been merged into
ceph_osd_linger_request.

All the details are now hidden within libceph, the interface consists
of a simple pair of watch/unwatch functions and ceph_osdc_notify_ack().
ceph_osdc_watch() does return ceph_osd_linger_request, but only to keep
the lifetime management simple.

ceph_osdc_notify_ack() accepts an optional data payload, which is
relayed back to the notifier.

Portions of this patch are loosely based on work by Douglas Fuller
 and Mike Christie .

Signed-off-by: Ilya Dryomov

rbd: rbd_dev_header_unwatch_sync() variant

2016-05-25T23:14:06+00:00

Introduce __rbd_dev_header_unwatch_sync(), which doesn't flush notify
callbacks.  This is for the new rados_watcherrcb_t, which would be
called from a notify callback.

Signed-off-by: Ilya Dryomov

libceph: drop msg argument from ceph_osdc_callback_t

2016-05-25T22:36:27+00:00

finish_read(), its only user, uses it to get to hdr.data_len, which is
what ->r_result is set to on success.  This gains us the ability to
safely call callbacks from contexts other than reply, e.g. map check.

Signed-off-by: Ilya Dryomov

libceph: switch to calc_target(), part 2

2016-05-25T22:36:27+00:00

The crux of this is getting rid of ceph_osdc_build_request(), so that
MOSDOp can be encoded not before but after calc_target() calculates the
actual target.  Encoding now happens within ceph_osdc_start_request().

Also nuked is the accompanying bunch of pointers into the encoded
buffer that was used to update fields on each send - instead, the
entire front is re-encoded.  If we want to support target->name_len !=
base->name_len in the future, there is no other way, because oid is
surrounded by other fields in the encoded buffer.

Encoding OSD ops and adding data items to the request message were
mixed together in osd_req_encode_op().  While we want to re-encode OSD
ops, we don't want to add duplicate data items to the message when
resending, so all call to ceph_osdc_msg_data_add() are factored out
into a new setup_request_data().

Signed-off-by: Ilya Dryomov

rbd: use header_oid instead of header_name

2016-05-25T22:36:22+00:00

Switch to ceph_object_id and use ceph_oid_aprintf() instead of a bare
const char *.  This reduces noise in rbd_dev_header_name().

Signed-off-by: Ilya Dryomov

libceph: variable-sized ceph_object_id

2016-05-25T22:36:22+00:00

Currently ceph_object_id can hold object names of up to 100
(CEPH_MAX_OID_NAME_LEN) characters.  This is enough for all use cases,
expect one - long rbd image names:

- a format 1 header is named ".rbd"
- an object that points to a format 2 header is named "rbd_id."

We operate on these potentially long-named objects during rbd map, and,
for format 1 images, during header refresh.  (A format 2 header name is
a small system-generated string.)

Lift this 100 character limit by making ceph_object_id be able to point
to an externally-allocated string.  Apart from being able to work with
almost arbitrarily-long named objects, this allows us to reduce the
size of ceph_object_id from >100 bytes to 64 bytes.

Signed-off-by: Ilya Dryomov

libceph: move message allocation out of ceph_osdc_alloc_request()

2016-05-25T22:36:21+00:00

The size of ->r_request and ->r_reply messages depends on the size of
the object name (ceph_object_id), while the size of ceph_osd_request is
fixed.  Move message allocation into a separate function that would
have to be called after ceph_object_id and ceph_object_locator (which
is also going to become variable in size with RADOS namespaces) have
been filled in:

    req = ceph_osdc_alloc_request(...);
    r_base_oid>
    r_base_oloc>
    ceph_osdc_alloc_messages(req);

Signed-off-by: Ilya Dryomov

rbd: get/put img_request in rbd_img_request_submit()

2016-05-25T22:36:20+00:00

By the time we get to checking for_each_obj_request_safe(img_request)
terminating condition, all obj_requests may be complete and img_request
ref, that rbd_img_request_submit() takes away from its caller, may be
put.  Moving the next_obj_request cursor is then a use-after-free on
img_request.

It's totally benign, as the value that's read is never used, but
I think it's still worth fixing.

Cc: Alex Elder 
Signed-off-by: Ilya Dryomov