Return error to original caller if register_session() fails.
Signed-off-by: NSage Weil <sage@newdream.net>

Currently, if the wait_event_interruptible is interrupted, we
return EAGAIN unconditionally and loop, such that we aren't, in
fact, interruptible.  So, propagate ERESTARTSYS if we get it.
Signed-off-by: NSage Weil <sage@newdream.net>

We were rebuilding the snap context when it was not necessary
(i.e. when the realm seq hadn't changed _and_ the parent seq
was still older), which caused page snapc pointers to not match
the realm's snapc pointer (even though the snap context itself
was identical).  This confused begin_write and put it into an
endless loop.

The correct logic is: rebuild snapc if _my_ realm seq changed, or
if my parent realm's seq is newer than mine (and thus mine needs
to be rebuilt too).
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>

The messenger fault was clearing the BUSY bit, for reasons unclear.  This
made it possible for the con->ops->fault function to reopen the connection,
and requeue work in the workqueue--even though the current thread was
already in con_work.

This avoids a problem where the client busy loops with connection failures
on an unreachable OSD, but doesn't address the root cause of that problem.
Signed-off-by: NSage Weil <sage@newdream.net>

Prevent duplicate 'mds0 caps stale' message from spamming the console every
few seconds while the MDS restarts.  Set s_renew_requested earlier, so that
we only print the message once, even if we don't send an actual request.
Signed-off-by: NSage Weil <sage@newdream.net>

The incremental map decoding of pg pool updates wasn't skipping
the snaps and removed_snaps vectors.  This caused osd requests
to stall when pool snapshots were created or fs snapshots were
deleted.  Use a common helper for full and incremental map
decoders that decodes pools properly.
Signed-off-by: NSage Weil <sage@newdream.net>

The wait_unsafe_requests() helper dropped the mdsc mutex to wait
for each request to complete, and then examined r_node to get the
next request after retaking the lock.  But the request completion
removes the request from the tree, so r_node was always undefined
at this point.  Since it's a small race, it usually led to a
valid request, but not always.  The result was an occasional
crash in rb_next() while dereferencing node->rb_left.

Fix this by clearing the rb_node when removing the request from
the request tree, and not walking off into the weeds when we
are done waiting for a request.  Since the request we waited on
will _always_ be out of the request tree, take a ref on the next
request, in the hopes that it won't be.  But if it is, it's ok:
we can start over from the beginning (and traverse over older read
requests again).
Signed-off-by: NSage Weil <sage@newdream.net>

We were releasing used caps (e.g. FILE_CACHE) from encode_inode_release
with MDS requests (e.g. setattr).  We don't carry refs on most caps, so
this code worked most of the time, but for setattr (utimes) we try to
drop Fscr.

This causes cap state to get slightly out of sync with reality, and may
result in subsequent mds revoke messages getting ignored.

Fix by only releasing unused caps.
Signed-off-by: NSage Weil <sage@newdream.net>

Drop session mutex unconditionally in handle_cap_grant, and do the
check_caps from the handle_cap_grant helper.  This avoids using a magic
return value.

Also avoid using a flag variable in the IMPORT case and call
check_caps at the appropriate point.
Signed-off-by: NSage Weil <sage@newdream.net>

Passing a session pointer to ceph_check_caps() used to mean it would leave
the session mutex locked.  That wasn't always possible if it wasn't passed
CHECK_CAPS_AUTHONLY.   If could unlock the passed session and lock a
differet session mutex, which was clearly wrong, and also emitted a
warning when it a racing CPU retook it and we did an unlock from the wrong
context.

This was only a problem when there was more than one MDS.

First, make ceph_check_caps unconditionally drop the session mutex, so that
it is free to lock other sessions as needed.  Then adjust the one caller
that passes in a session (handle_cap_grant) accordingly.
Signed-off-by: NSage Weil <sage@newdream.net>

If we don't have the exported cap it's because we already released it. No
need to WARN.
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>

Previously we would decode state directly into our current ticket_handler.
This is problematic if for some reason we fail to decode, because we end
up with half new state and half old state.

We are probably already in bad shape if we get an update we can't decode,
but we may as well be tidy anyway.  Decode into new_* temporaries and
update the ticket_handler only on success.
Signed-off-by: NSage Weil <sage@newdream.net>

Release the old ticket_blob buffer when we get an updated service ticket
from the monitor.  Previously these were getting leaked.
Signed-off-by: NSage Weil <sage@newdream.net>

The buffer size was incorrectly calculated for the ceph_x_encrypt()
encapsulated ticket blob.  Use a helper (with correct arithmetic) and
BUG out if we were wrong.
Signed-off-by: NSage Weil <sage@newdream.net>

We were failing to reconnect to services due to an old authenticator, even
though we had the new ticket, because we weren't properly retrying the
connect handshake, because we were calling an old/incorrect helper that
left in_base_pos incorrect.  The result was a failure to reconnect to the
OSD or MDS (with an authentication error) if the MDS restarted after the
service had been up a few hours (long enough for the original authenticator
to be invalid).  This was only a problem if the AUTH_X authentication was
enabled.

Now that the 'negotiate' and 'connect' stages are fully separated, we
should use the prepare_read_connect() helper instead, and remove the
obsolete one.
Signed-off-by: NSage Weil <sage@newdream.net>

When an inode was dropped while being migrated between two MDSs,
i_cap_exporting_issued was non-zero such that issue caps were non-zero and
__ceph_is_any_caps(ci) was true.  This prevented the inode from being
removed from the snap realm, even as it was dropped from the cache.

Fix this by dropping any residual i_snap_realm ref in destroy_inode.
Signed-off-by: NSage Weil <sage@newdream.net>

All ci->i_snap_realm_item/realm->inodes_with_caps manipulation should be
protected by realm->inodes_with_caps_lock.  This bug would have only bit
us in a rare race with a realm split (during some snap creations).
Signed-off-by: NSage Weil <sage@newdream.net>

Added assertion, and cleared one case where the implemented caps were
not following the issued caps.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
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>

The flush_dirty_caps() used to loop over the first entry of the cap_dirty
dirty list on the assumption that after calling ceph_check_caps() it would
be removed from the list.  This isn't true for caps that are being
migrated between MDSs, where we've received the EXPORT but not the IMPORT.

Instead, do a safe list iteration, and pin the next inode on the list via
the CEPH_I_NOFLUSH flag.
Signed-off-by: NSage Weil <sage@newdream.net>

We should include caps that are mid-migration (we've received the EXPORT,
but not the IMPORT) in the issued caps set.
Signed-off-by: NSage Weil <sage@newdream.net>

Add missing pointer dereference (p is a void **).
Signed-off-by: NSage Weil <sage@newdream.net>

Verify the file is actually open for the given caps when we are
waiting for caps.  This ensures we will wake up and return EBADF
if another thread closes the file out from under us.

Note that EBADF is also the correct return code from write(2)
when called on a file handle opened for reading (although the
vfs should catch that).
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>

Reset msg front len when a message is returned to the pool: the caller
may have changed it.

BUG if we try to send a message with a hdr.front_len that doesn't match
the front iov.
Signed-off-by: NSage Weil <sage@newdream.net>

This was simply broken.  Apparently at some point we thought about putting
the snaptrace in the middle section, but didn't.
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>

Clear LOSSYTX bit, so that if/when we reconnect, said reconnect
will retry on failure.

Clear _PENDING bits too, to avoid polluting subsequent
connection state.

Drop unused REGISTERED bit.
Signed-off-by: NSage Weil <sage@newdream.net>

The must_resend flag is always true, not false.  In any case, we can
just ignore it anyway.
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>

Move any out_sent messages to out_queue _before_ checking if
out_queue is empty and going to STANDBY, or else we may drop
something that was never acked.

And clean up the code a bit (less goto).
Signed-off-by: NSage Weil <sage@newdream.net>

This fixes lock ABBA inversion, as the ->invalidate_authorizer()
op may need to take a lock (or even call back into the
messenger).
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

The tid is in the message header, not body.  Broken since 6df058c0.

No need to look at next mds session; just mark the request and be done.
(The old error path was broken too, but now it's gone.)
Signed-off-by: NSage Weil <sage@newdream.net>

Verify the mds session is currently registered before handling
incoming messages.  Clean up message handlers to pull mds out
of session->s_mds instead of less trustworthy src field.

Clean up con_{get,put} debug output.
Signed-off-by: NSage Weil <sage@newdream.net>

The destroy_inode path needs no inode locks since there are no
inode references.  Update __ceph_remove_cap comment to reflect
that it is called without cap->session->s_mutex in this case.
Signed-off-by: NSage Weil <sage@newdream.net>