Export the info used to setup the rbd image, so it can be used to remap
the image.
Signed-off-by: NMike Christie <mchristi@redhat.com>
[idryomov@gmail.com: do_rbd_add() EH]
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Export snap id in sysfs, so tools like multipathd can use it in a uuid.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Export the cluster fsid, so tools like udev and multipath-tools can use
it for part of the uuid.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Export client addr/nonce, so userspace can check if a image is being
blacklisted.
Signed-off-by: NMike Christie <mchristi@redhat.com>
[idryomov@gmail.com: ceph_client_addr(), endianess fix]
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

With exclusive-lock added and more to come, print features into dmesg.
Change capacity to decimal while at it.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NMike Christie <mchristi@redhat.com>

Add basic support for RBD_FEATURE_EXCLUSIVE_LOCK feature.  Maintenance
operations (resize, snapshot create, etc) are offloaded to librbd via
returning -EOPNOTSUPP - librbd should request the lock and execute the
operation.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NMike Christie <mchristi@redhat.com>
Tested-by: NMike Christie <mchristi@redhat.com>

Revamp watch code to support retrying watch re-registration:

- add rbd_dev->watch_state for more robust errcb handling
- store watch cookie separately to avoid dereferencing watch_handle
  which is set to NULL on unwatch
- move re-register code into a delayed work and retry re-registration
  every second, unless the client is blacklisted
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NMike Christie <mchristi@redhat.com>
Tested-by: NMike Christie <mchristi@redhat.com>

This is going to be used for re-registering watch requests and
exclusive-lock tasks: acquire/request lock, notify-acquired, release
lock, notify-released.  Some refactoring in the map/unmap paths was
necessary to give this workqueue a meaningful name: "rbdX-tasks".
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NMike Christie <mchristi@redhat.com>

It's gid / global_id in other places.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NMike Christie <mchristi@redhat.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

ceph_file_layout::pool_id is now s64.  rbd_add_get_pool_id() and
ceph_pg_poolid_by_name() both return an int, so it's bogus anyway.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

Purely cosmetic at this point, as rbd doesn't use RADOS namespaces and
hence rbd_dev->header_oloc->pool_ns is always NULL.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Add pool namesapce pointer to struct ceph_file_layout and struct
ceph_object_locator. Pool namespace is used by when mapping object
to PG, it's also used when composing OSD request.

The namespace pointer in struct ceph_file_layout is RCU protected.
So libceph can read namespace without taking lock.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
[idryomov@gmail.com: ceph_oloc_destroy(), misc minor changes]
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Define new ceph_file_layout structure and rename old ceph_file_layout
to ceph_file_layout_legacy. This is preparation for adding namespace
to ceph_file_layout structure.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

The req operation REQ_OP is separated from the rq_flag_bits
definition. This converts the block layer drivers to
use req_op to get the op from the request struct.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

... with a wrapper around maybe_request_map() - no need for two
osdmap-specific functions.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

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: NIlya Dryomov <idryomov@gmail.com>

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
<dfuller@redhat.com> and Mike Christie <michaelc@cs.wisc.edu>.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

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: NIlya Dryomov <idryomov@gmail.com>

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: NIlya Dryomov <idryomov@gmail.com>

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: NIlya Dryomov <idryomov@gmail.com>

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: NIlya Dryomov <idryomov@gmail.com>

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

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: NIlya Dryomov <idryomov@gmail.com>

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(...);
    <fill in req->r_base_oid>
    <fill in req->r_base_oloc>
    ceph_osdc_alloc_messages(req);
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

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 <elder@linaro.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

... instead of just returning an error.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJosh Durgin <jdurgin@redhat.com>

A while ago, commit 9875201e ("rbd: fix use-after free of
rbd_dev->disk") fixed rbd unmap vs notify race by introducing
an exported wrapper for flushing notifies and sticking it into
do_rbd_remove().

A similar problem exists on the rbd map path, though: the watch is
registered in rbd_dev_image_probe(), while the disk is set up quite
a few steps later, in rbd_dev_device_setup().  Nothing prevents
a notify from coming in and crashing on a NULL rbd_dev->disk:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
    Call Trace:
     [<ffffffffa0508344>] rbd_watch_cb+0x34/0x180 [rbd]
     [<ffffffffa04bd290>] do_event_work+0x40/0xb0 [libceph]
     [<ffffffff8109d5db>] process_one_work+0x17b/0x470
     [<ffffffff8109e3ab>] worker_thread+0x11b/0x400
     [<ffffffff8109e290>] ? rescuer_thread+0x400/0x400
     [<ffffffff810a5acf>] kthread+0xcf/0xe0
     [<ffffffff810b41b3>] ? finish_task_switch+0x53/0x170
     [<ffffffff810a5a00>] ? kthread_create_on_node+0x140/0x140
     [<ffffffff81645dd8>] ret_from_fork+0x58/0x90
     [<ffffffff810a5a00>] ? kthread_create_on_node+0x140/0x140
    RIP  [<ffffffffa050828a>] rbd_dev_refresh+0xfa/0x180 [rbd]

If an error occurs during rbd map, we have to error out, potentially
tearing down a watch.  Just like on rbd unmap, notifies have to be
flushed, otherwise rbd_watch_cb() may end up trying to read in the
image header after rbd_dev_image_release() has run:

    Assertion failure in rbd_dev_header_info() at line 4722:

     rbd_assert(rbd_image_format_valid(rbd_dev->image_format));

    Call Trace:
     [<ffffffff81cccee0>] ? rbd_parent_request_create+0x150/0x150
     [<ffffffff81cd4e59>] rbd_dev_refresh+0x59/0x390
     [<ffffffff81cd5229>] rbd_watch_cb+0x69/0x290
     [<ffffffff81fde9bf>] do_event_work+0x10f/0x1c0
     [<ffffffff81107799>] process_one_work+0x689/0x1a80
     [<ffffffff811076f7>] ? process_one_work+0x5e7/0x1a80
     [<ffffffff81132065>] ? finish_task_switch+0x225/0x640
     [<ffffffff81107110>] ? pwq_dec_nr_in_flight+0x2b0/0x2b0
     [<ffffffff81108c69>] worker_thread+0xd9/0x1320
     [<ffffffff81108b90>] ? process_one_work+0x1a80/0x1a80
     [<ffffffff8111b02d>] kthread+0x21d/0x2e0
     [<ffffffff8111ae10>] ? kthread_stop+0x550/0x550
     [<ffffffff82022802>] ret_from_fork+0x22/0x40
     [<ffffffff8111ae10>] ? kthread_stop+0x550/0x550
    RIP  [<ffffffff81ccd8f9>] rbd_dev_header_info+0xa19/0x1e30

To fix this, a) check if RBD_DEV_FLAG_EXISTS is set before calling
revalidate_disk(), b) move ceph_osdc_flush_notifies() call into
rbd_dev_header_unwatch_sync() to cover rbd map error paths and c) turn
header read-in into a critical section.  The latter also happens to
take care of rbd map foo@bar vs rbd snap rm foo@bar race.

Fixes: http://tracker.ceph.com/issues/15490Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJosh Durgin <jdurgin@redhat.com>

As of 5a60e876, RBD object request
allocations are made via rbd_obj_request_create() with GFP_NOIO.
However, subsequent OSD request allocations in rbd_osd_req_create*()
use GFP_ATOMIC.

With heavy page cache usage (e.g. OSDs running on same host as krbd
client), rbd_osd_req_create() order-1 GFP_ATOMIC allocations have been
observed to fail, where direct reclaim would have allowed GFP_NOIO
allocations to succeed.

Cc: stable@vger.kernel.org # 3.18+
Suggested-by: NVlastimil Babka <vbabka@suse.cz>
Suggested-by: NNeil Brown <neilb@suse.com>
Signed-off-by: NDavid Disseldorp <ddiss@suse.de>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Use KMEM_CACHE() instead of kmem_cache_create() to simplify the code.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Turn r_ops into a flexible array member to enable large, consisting of
up to 16 ops, OSD requests.  The use case is scattered writeback in
cephfs and, as far as the kernel client is concerned, 16 is just a made
up number.

r_ops had size 3 for copyup+hint+write, but copyup is really a special
case - it can only happen once.  ceph_osd_request_cache is therefore
stuffed with num_ops=2 requests, anything bigger than that is allocated
with kmalloc().  req_mempool is backed by ceph_osd_request_cache, which
means either num_ops=1 or num_ops=2 for use_mempool=true - all existing
users (ceph_writepages_start(), ceph_osdc_writepages()) are fine with
that.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

This avoids defining large array of r_reply_op_{len,result} in
in struct ceph_osd_request.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

The rbd_dev_destroy() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Commit 4e752f0a ("rbd: access snapshot context and mapping size
safely") moved ceph_get_snap_context() out of rbd_img_request_create()
and into rbd_queue_workfn(), adding a ceph_put_snap_context() to the
error path in rbd_queue_workfn().  However, rbd_img_request_create()
consumes a ref on snapc, so calling ceph_put_snap_context() after
a successful rbd_img_request_create() leads to an extra put.  Fix it.

Cc: stable@vger.kernel.org # 3.18+
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJosh Durgin <jdurgin@redhat.com>

Commit d1cf5788 ("rbd: set mapping info earlier") defined
rbd_dev_mapping_clear(), but, just a few days after, commit
f35a4dee ("rbd: set the mapping size and features later") moved
rbd_dev_mapping_set() calls and added another rbd_dev_mapping_clear()
call instead of moving the old one.  Around the same time, another
duplicate was introduced in rbd_dev_device_release() - kill both.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

No point in providing an empty device_type::release callback and then
setting device::release for each rbd_dev dynamically.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

struct rbd_device has struct device embedded in it, which means it's
part of kobject universe and has an unpredictable life cycle.  Freeing
its memory outside of the release callback is flawed, yet commits
200a6a8b ("rbd: don't destroy rbd_dev in device release function")
and 8ad42cd0 ("rbd: don't have device release destroy rbd_dev")
moved rbd_dev_destroy() out to rbd_dev_image_release().

This commit reverts most of that, the key points are:

- rbd_dev->dev is initialized in rbd_dev_create(), making it possible
  to use rbd_dev_destroy() - which is just a put_device() - both before
  we register with device core and after.

- rbd_dev_release() (the release callback) is the only place we
  kfree(rbd_dev).  It's also where we do module_put(), keeping the
  module unload race window as small as possible.

- We pin the module in rbd_dev_create(), but only for mapping
  rbd_dev-s.  Moving image related stuff out of struct rbd_device into
  another struct which isn't tied with sysfs and device core is long
  overdue, but until that happens, this will keep rbd module refcount
  (which users can observe with lsmod) sane.

Fixes: http://tracker.ceph.com/issues/12697

Cc: Alex Elder <elder@linaro.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Returning pool id (i.e. >= 0) from a sysfs ->store() callback makes
userspace think it needs to retry the write.  Fix it - it's a leftover
from the times when the equivalent of rbd_dev_create() was the first
action in rbd_add().
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ expression x; @@
-if (x != NULL) {
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
  x = NULL;
-}
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

rbd requires stable pages, as it performs a crc of the page data before
they are send to the OSDs.

But since kernel 3.9 (patch 1d1d1a76
"mm: only enforce stable page writes if the backing device requires
it") it is not assumed anymore that block devices require stable pages.

This patch sets the necessary flag to get stable pages back for rbd.

In a ceph installation that provides multiple ext4 formatted rbd
devices "bad crc" messages appeared regularly (ca 1 message every 1-2
minutes on every OSD that provided the data for the rbd) in the
OSD-logs before this patch. After this patch this messages are pretty
much gone (only ca 1-2 / month / OSD).

Cc: stable@vger.kernel.org # 3.9+, needs backporting
Signed-off-by: NRonny Hegewald <Ronny.Hegewald@online.de>
[idryomov@gmail.com: require stable pages only in crc case, changelog]
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Mapping an image with a long parent chain (e.g. image foo, whose parent
is bar, whose parent is baz, etc) currently leads to a kernel stack
overflow, due to the following recursion in the reply path:

  rbd_osd_req_callback()
    rbd_obj_request_complete()
      rbd_img_obj_callback()
        rbd_img_parent_read_callback()
          rbd_obj_request_complete()
            ...

Limit the parent chain to 16 images, which is ~5K worth of stack.  When
the above recursion is eliminated, this limit can be lifted.

Fixes: http://tracker.ceph.com/issues/12538

Cc: stable@vger.kernel.org # 3.10+, needs backporting for < 4.2
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NJosh Durgin <jdurgin@redhat.com>

Currently we leak parent_spec and trigger a "parent reference
underflow" warning if rbd_dev_create() in rbd_dev_probe_parent() fails.
The problem is we take the !parent out_err branch and that only drops
refcounts; parent_spec that would've been freed had we called
rbd_dev_unparent() remains and triggers rbd_warn() in
rbd_dev_parent_put() - at that point we have parent_spec != NULL and
parent_ref == 0, so counter ends up being -1 after the decrement.

Redo rbd_dev_probe_parent() to fix this.

Cc: stable@vger.kernel.org # 3.10+, needs backporting for < 4.2
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NAlex Elder <elder@linaro.org>