The function ceph_alloc_msg() is only used to allocate a message
that will be assigned to a connection's in_msg pointer.  Rename the
function so this implied usage is more clear.

In addition, make that assignment inside the function (again, since
that's precisely what it's intended to be used for).  This allows us
to return what is now provided via the passed-in address of a "skip"
variable.  The return type is now Boolean to be explicit that there
are only two possible outcomes.

Make sure the result of an ->alloc_msg method call always sets the
value of *skip properly.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Move the initialization of a ceph connection's private pointer,
operations vector pointer, and peer name information into
ceph_con_init().  Rearrange the arguments so the connection pointer
is first.  Hide the byte-swapping of the peer entity number inside
ceph_con_init()
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

There were a few direct calls to ceph_con_{get,put}() instead of the con
ops from osd_client.c.  This is a bug since those ops aren't defined to
be ceph_con_get/put.

This breaks refcounting on the ceph_osd structs that contain the
ceph_connections, and could lead to all manner of strangeness.

The purpose of the ->get and ->put methods in a ceph connection are
to allow the connection to indicate it has a reference to something
external to the messaging system, *not* to indicate something
external has a reference to the connection.

[elder@inktank.com: added that last sentence]
Signed-off-by: NSage Weil <sage@newdream.net>
Reviewed-by: NAlex Elder <elder@inktank.com>

In ceph_osdc_release_request(), a reference to the r_reply message
is dropped.  But just after that, that same message is revoked if it
was in use to receive an incoming reply.  Reorder these so we are
sure we hold a reference until we're actually done with the message.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Pass the osd number to the create_osd() routine, and move the
initialization of fields that depend on it therein.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

A ceph client has a pointer to a ceph messenger structure in it.
There is always exactly one ceph messenger for a ceph client, so
there is no need to allocate it separate from the ceph client
structure.

Switch the ceph_client structure to embed its ceph_messenger
structure.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYehuda Sadeh <yehuda@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

There is a race between two __unregister_request() callers: the
reply path and the ceph_osdc_wait_request().  If we get a reply
*and* the timeout expires at roughly the same time, both callers
will try to unregister the request, and the second one will do bad
things.

Simply check if the request is still already unregistered; if so,
return immediately and do nothing.

Fixes http://tracker.newdream.net/issues/2420Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

Rather than passing a bunch of arguments to be filled in with the
content of the ceph_auth_handshake buffer now returned by the
get_authorizer method, just use the returned information in the
caller, and drop the unnecessary arguments.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Have the get_authorizer auth_client method return a ceph_auth
pointer rather than an integer, pointer-encoding any returned
error value.  This is to pave the way for making use of the
returned value in an upcoming patch.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

In the create_authorizer method for both the mds and osd clients,
the auth_client->ops pointer is blindly dereferenced.  There is no
obvious guarantee that this pointer has been assigned.  And
furthermore, even if the ops pointer is non-null there is definitely
no guarantee that the create_authorizer or destroy_authorizer
methods are defined.

Add checks in both routines to make sure they are defined (non-null)
before use.  Add similar checks in a few other spots in these files
while we're at it.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Make use of the new ceph_auth_handshake structure in order to reduce
the number of arguments passed to the create_authorizor method in
ceph_auth_client_ops.  Use a local variable of that type as a
shorthand in the get_authorizer method definitions.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

The definitions for the ceph_mds_session and ceph_osd both contain
five fields related only to "authorizers."  Encapsulate those fields
into their own struct type, allowing for better isolation in some
upcoming patches.

Fix the #includes in "linux/ceph/osd_client.h" to lay out their more
complete canonical path.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

From Al Viro <viro@zeniv.linux.org.uk>

Al Viro noticed that we were using a non-cpu-encoded value in
a switch statement in osd_req_encode_op().  The result would
clearly not work correctly on a big-endian machine.
Signed-off-by: NAlex Elder <elder@dreamhost.com>

Signed-off-by: NSage Weil <sage@newdream.net>

ceph_osd_request struct allocates a 40-byte buffer for object names.
RBD image names can be up to 96 chars long (100 with the .rbd suffix),
which results in the object name for the image being truncated, and a
subsequent map failure.

Increase the oid buffer in request messages, in order to avoid the
truncation.
Signed-off-by: NStratos Psomadakis <psomas@grnet.gr>
Signed-off-by: NSage Weil <sage@newdream.net>

If we skip over one or more map epochs, we need to resend all osd requests
because it is possible they remapped to other servers and then back.
Signed-off-by: NSage Weil <sage@newdream.net>

The pool allocation failures are masked by the pool; there is no need to
spam the console about them.  (That's the whole point of having the pool
in the first place.)

Mark msg allocations whose failure is safely handled as such.
Signed-off-by: NSage Weil <sage@newdream.net>

The r_req_lru_item list node moves between several lists, and that cycle
is not directly related (and does not begin) with __register_request().
Initialize it in the request constructor, not __register_request(). This
fixes later badness (below) when OSDs restart underneath an rbd mount.

Crashes we've seen due to this include:

[  213.974288] kernel BUG at net/ceph/messenger.c:2193!

and

[  144.035274] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
[  144.035278] IP: [<ffffffffa036c053>] con_work+0x1463/0x2ce0 [libceph]
Signed-off-by: NSage Weil <sage@newdream.net>

We want to remove all OSDs, not just those on the idle LRU.
Signed-off-by: NSage Weil <sage@newdream.net>

Keep track of when an outgoing message is ACKed (i.e., the server fully
received it and, presumably, queued it for processing).  Time out OSD
requests only if it's been too long since they've been received.

This prevents timeouts and connection thrashing when the OSDs are simply
busy and are throttling the requests they read off the network.
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Set the page count correctly for non-page-aligned IO.  We were already
doing this correctly for alignment, but not the page count.  Fixes
DIRECT_IO writes from unaligned pages.
Signed-off-by: NSage Weil <sage@newdream.net>

If we cancel a write, trigger the safe completions to prevent a sync from
blocking indefinitely in ceph_osdc_sync().
Signed-off-by: NSage Weil <sage@newdream.net>

When the cluster is marked full, subscribe to subsequent map updates to
ensure we find out promptly when it is no longer full.  This will prevent
us from spewing ENOSPC for (much) longer than necessary.
Signed-off-by: NSage Weil <sage@newdream.net>

Since we pass the nofail arg, we should never get an error; BUG if we do.
(And fix the function to not return an error if __map_request fails.)
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

ceph_osdc_alloc_request returns NULL on failure.
Signed-off-by: NSage Weil <sage@newdream.net>

Fix the request transition from linger -> normal request.  The key is to
preserve r_osd and requeue on the same OSD.  Reregister as a normal request,
add the request to the proper queues, then unregister the linger.  Fix the
unregister helper to avoid clearing r_osd (and also simplify the parallel
check in __unregister_request()).
Reported-by: NHenry Chang <henry.cy.chang@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

We should only clear r_osd if we are neither registered as a linger or a
regular request.  We may unregister as a linger while still registered as
a regular request (e.g., in reset_osd).  Incorrectly clearing r_osd there
leads to a null pointer dereference in __send_request.

Also simplify the parallel check in __unregister_request() where we just
removed r_osd_item and know it's empty.
Signed-off-by: NSage Weil <sage@newdream.net>

There was a missing unlock on the error path if __map_request() failed.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

This patch fixes 'event_work' dereference before it is checked for NULL.
Signed-off-by: NMariusz Kozlowski <mk@lab.zgora.pl>
Signed-off-by: NSage Weil <sage@newdream.net>

Lingering requests are requests that are sent to the OSD normally but
tracked also after we get a successful request.  This keeps the OSD
connection open and resends the original request if the object moves to
another OSD.  The OSD can then send notification messages back to us
if another client initiates a notify.

This framework will be used by RBD so that the client gets notification
when a snapshot is created by another node or tool.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

If we send a request to osd A, and the request's pg remaps to osd B and
then back to A in quick succession, we need to resend the request to A. The
old code was only calling kick_requests after processing all incremental
maps in a message, so it was very possible to not resend a request that
needed to be resent.  This would make the osd eventually time out (at least
with the current default of osd timeouts enabled).

The correct approach is to scan requests on every map incremental.  This
patch refactors the kick code in a few ways:
 - all requests are either on req_lru (in flight), req_unsent (ready to
   send), or req_notarget (currently map to no up osd)
 - mapping always done by map_request (previous map_osds)
 - if the mapping changes, we requeue.  requests are resent only after all
   map incrementals are processed.
 - some osd reset code is moved out of kick_requests into a separate
   function
 - the "kick this osd" functionality is moved to kick_osd_requests, as it
   is unrelated to scanning for request->pg->osd mapping changes
Signed-off-by: NSage Weil <sage@newdream.net>

The alignment used for reading data into or out of pages used to be taken
from the data_off field in the message header.  This only worked as long
as the page alignment matched the object offset, breaking direct io to
non-page aligned offsets.

Instead, explicitly specify the page alignment next to the page vector
in the ceph_msg struct, and use that instead of the message header (which
probably shouldn't be trusted).  The alloc_msg callback is responsible for
filling in this field properly when it sets up the page vector.
Signed-off-by: NSage Weil <sage@newdream.net>

We used to infer alignment of IOs within a page based on the file offset,
which assumed they matched.  This broke with direct IO that was not aligned
to pages (e.g., 512-byte aligned IO).  We were also trusting the alignment
specified in the OSD reply, which could have been adjusted by the server.

Explicitly specify the page alignment when setting up OSD IO requests.
Signed-off-by: NSage Weil <sage@newdream.net>

This factors out protocol and low-level storage parts of ceph into a
separate libceph module living in net/ceph and include/linux/ceph.  This
is mostly a matter of moving files around.  However, a few key pieces
of the interface change as well:

 - ceph_client becomes ceph_fs_client and ceph_client, where the latter
   captures the mon and osd clients, and the fs_client gets the mds client
   and file system specific pieces.
 - Mount option parsing and debugfs setup is correspondingly broken into
   two pieces.
 - The mon client gets a generic handler callback for otherwise unknown
   messages (mds map, in this case).
 - The basic supported/required feature bits can be expanded (and are by
   ceph_fs_client).

No functional change, aside from some subtle error handling cases that got
cleaned up in the refactoring process.
Signed-off-by: NSage Weil <sage@newdream.net>

This will be used for rbd snapshots administration.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>

Allow the messenger to send/receive data in a bio.  This is added
so that we wouldn't need to copy the data into pages or some other buffer
when doing IO for an rbd block device.

We can now have trailing variable sized data for osd
ops.  Also osd ops encoding is more modular.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

The osd requests creation are being decoupled from the
vino parameter, allowing clients using the osd to use
other arbitrary object names that are not necessarily
vino based. Also, calc_raw_layout now takes a snap id.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

If we interrupt an osd request, we call __cancel_request, but it wasn't
verifying that req->r_osd was non-NULL before dereferencing it.  This could
cause a crash if osds were flapping and we aborted a request on said osd.
Reported-by: NHenry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: NSage Weil <sage@newdream.net>