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>

Fix argument order.  We want to move the item to the end of the list, not
change the position of the head.
Signed-off-by: NHenry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: NSage Weil <sage@newdream.net>

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

Setting it elsewhere is unnecessary and more fragile.
Signed-off-by: NSage Weil <sage@newdream.net>

This fixes an issue triggered by running concurrent syncs. One of the syncs
would go through while the other would just hang indefinitely. In any case, we
never actually want to wake a single waiter, so the *_all functions should
be used.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Don't leak message if we receive an unexpected message type.
Signed-off-by: NSage Weil <sage@newdream.net>

Release the ceph_authorizer when releasing osd state.
Signed-off-by: NSage Weil <sage@newdream.net>

The C99 specification states in section 6.11.5:

The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NSage Weil <sage@newdream.net>

This is essential, as for the rados block device we'll need
to run in different contexts that would need flags that
are other than GFP_NOFS.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

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

Allow the osd reset timeout to be disabled.
Signed-off-by: NSage Weil <sage@newdream.net>

Now that the mount thread waits for the osdmap, it needs
to be awaken.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>

We only need to pass in front_len.  Callers can attach any other payload
pieces (middle, data) as they see fit.
Signed-off-by: NSage Weil <sage@newdream.net>

Returning ERR_PTR(-ENOMEM) is useless extra work.  Return NULL on failure
instead, and fix up the callers (about half of which were wrong anyway).
Signed-off-by: NSage Weil <sage@newdream.net>

This would only trigger if we bailed out before resetting r_con_filling_msg
because the server reply was corrupt (oversized).
Signed-off-by: NSage Weil <sage@newdream.net>

Drop largely useless helper __prepare_pages(), and simplify sanity checks.
Signed-off-by: NSage Weil <sage@newdream.net>

OSD requests need to be resubmitted on any pg mapping change, not just when
the pg primary changes.  Resending only when the primary changes results in
occasional 'hung' requests during osd cluster recovery or rebalancing.
Signed-off-by: NSage Weil <sage@newdream.net>

The osd request wasn't being unregistered when the osd returned a failure
code, even though the result was returned to the caller.  This would cause
it to eventually time out, and then crash the kernel when it tried to
resend the request using a stale page vector.
Signed-off-by: NSage Weil <sage@newdream.net>

We get a fault callback on _every_ tcp connection fault.  Normally, we
want to reopen the connection when that happens.  If the address we have
is bad, however, and connection attempts always result in a connection
refused or similar error, explicitly closing and reopening the msgr
connection just prevents the messenger's backoff logic from kicking in.
The result can be a console full of

[ 3974.417106] ceph: osd11 10.3.14.138:6800 connection failed
[ 3974.423295] ceph: osd11 10.3.14.138:6800 connection failed
[ 3974.429709] ceph: osd11 10.3.14.138:6800 connection failed

Instead, if we get a fault, and have outstanding requests, but the osd
address hasn't changed and the connection never successfully connected in
the first place, do nothing to the osd connection.  The messenger layer
will back off and retry periodically, because we never connected and thus
the lossy bit is not set.

Instead, touch each request's r_stamp so that handle_timeout can tell the
request is still alive and kicking.
Signed-off-by: NSage Weil <sage@newdream.net>

Make variable name slightly more generic, since it will (soon)
reflect either the time the request was sent OR the time it was
last determined to be still retrying.
Signed-off-by: NSage Weil <sage@newdream.net>

This causes an oops when debug output is enabled and we kick
an osd request with no current r_osd (sometime after an osd
failure).  Check the pointer before dereferencing.
Signed-off-by: NSage Weil <sage@newdream.net>

This simplifies the process of timing out messages. We
keep lru of current messages that are in flight. If a
timeout has passed, we reset the osd connection, so that
messages will be retransmitted.  This is a failsafe in case
we hit some sort of problem sending out message to the OSD.
Normally, we'll get notification via an updated osdmap if
there are problems.

If a request is older than the keepalive timeout, send a
keepalive to ensure we detect any breaks in the TCP connection.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

We didn't set the front length correctly.  When messages used
the message pool we ended up with the conservative max (4 KB), and
the rest of the time the slightly less conservative estimate.  Even
though the OSD ignores the extra data, set it to the right value to avoid
sending extra data over the network.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Use a single ceph_msg for the osd reply, even when we are getting multiple
replies.
Signed-off-by: NSage Weil <sage@newdream.net>

We used to try to avoid freeing and then reallocating the osd
struct.  This is a bit fragile due to potential interactions with
other references (beyond o_requests), and may be the cause of
this crash:

[120633.442358] BUG: unable to handle kernel NULL pointer dereference at (null)
[120633.443292] IP: [<ffffffff812549b6>] rb_erase+0x11d/0x277
[120633.443292] PGD f7ff3067 PUD f7f53067 PMD 0
[120633.443292] Oops: 0000 [#1] PREEMPT SMP
[120633.443292] last sysfs file: /sys/kernel/uevent_seqnum
[120633.443292] CPU 1
[120633.443292] Modules linked in: ceph fan ac battery psmouse ehci_hcd ide_pci_generic ohci_hcd thermal processor button
[120633.443292] Pid: 3023, comm: ceph-msgr/1 Not tainted 2.6.32-rc2 #12 H8SSL
[120633.443292] RIP: 0010:[<ffffffff812549b6>]  [<ffffffff812549b6>] rb_erase+0x11d/0x277
[120633.443292] RSP: 0018:ffff8800f7b13a50  EFLAGS: 00010246
[120633.443292] RAX: ffff880022907819 RBX: ffff880022907818 RCX: 0000000000000000
[120633.443292] RDX: ffff8800f7b13a80 RSI: ffff8800f587eb48 RDI: 0000000000000000
[120633.443292] RBP: ffff8800f7b13a60 R08: 0000000000000000 R09: 0000000000000004
[120633.443292] R10: 0000000000000000 R11: ffff8800c4441000 R12: ffff8800f587eb48
[120633.443292] R13: ffff8800f58eaa00 R14: ffff8800f413c000 R15: 0000000000000001
[120633.443292] FS:  00007fbef6e226e0(0000) GS:ffff880009200000(0000) knlGS:0000000000000000
[120633.443292] CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[120633.443292] CR2: 0000000000000000 CR3: 00000000f7c53000 CR4: 00000000000006e0
[120633.443292] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[120633.443292] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[120633.443292] Process ceph-msgr/1 (pid: 3023, threadinfo ffff8800f7b12000, task ffff8800f5858b40)
[120633.443292] Stack:
[120633.443292]  ffff8800f413c000 ffff8800f587e9c0 ffff8800f7b13a80 ffffffffa0098a86
[120633.443292] <0> 00000000000006f1 0000000000000000 ffff8800f7b13af0 ffffffffa009959b
[120633.443292] <0> ffff8800f413c000 ffff880022a68400 ffff880022a68400 ffff8800f587e9c0
[120633.443292] Call Trace:
[120633.443292]  [<ffffffffa0098a86>] __remove_osd+0x4d/0xbc [ceph]
[120633.443292]  [<ffffffffa009959b>] __map_osds+0x199/0x4fa [ceph]
[120633.443292]  [<ffffffffa00999f4>] ? __send_request+0xf8/0x186 [ceph]
[120633.443292]  [<ffffffffa0099beb>] kick_requests+0x169/0x3cb [ceph]
[120633.443292]  [<ffffffffa009a8c1>] ceph_osdc_handle_map+0x370/0x522 [ceph]

Since we're probably screwed anyway if a small kmalloc is
failing, don't bother with trying to be clever here.
Signed-off-by: NSage Weil <sage@newdream.net>

Fix skipping of unexpected message types from osd, mon.

Clean up pr_info and debug output.
Signed-off-by: NSage Weil <sage@newdream.net>

A single osd connection fault (e.g. tcp disconnect) wasn't
reopening the connection, which causes all current and future
requests for that osd to hang.
Signed-off-by: NSage Weil <sage@newdream.net>

Instead of removing osd connection immediately when the
requests list is empty, put the osd connection on an lru.
Only if that osd has not been used for more than a specified
time, will it be removed.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Add infrastructure to allow the mon_client to periodically renew its auth
credentials.  Also add a messenger callback that will force such a renewal
if a peer rejects our authenticator.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>