sunrpc: Fix infinite loop in RPC state machine

commit 6ff33b7dd0228b7d7ed44791bbbc98b03fd15d9d upstream.

When a task enters call_refreshresult with status 0 from call_refresh and
!rpcauth_uptodatecred(task) it enters call_refresh again with no rate-limiting
or max number of retries.

Instead of trying forever, make use of the retry path that other errors use.

This only seems to be possible when the crrefresh callback is gss_refresh_null,
which only happens when destroying the context.

To reproduce:

1) mount with sec=krb5 (or sec=sys with krb5 negotiated for non FSID specific
   operations).

2) reboot - the client will be stuck and will need to be hard rebooted

BUG: soft lockup - CPU#0 stuck for 22s! [kworker/0:2:46]
Modules linked in: rpcsec_gss_krb5 nfsv4 nfs fscache ppdev crc32c_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd serio_raw i2c_piix4 i2c_core e1000 parport_pc parport shpchp nfsd auth_rpcgss oid_registry exportfs nfs_acl lockd sunrpc autofs4 mptspi scsi_transport_spi mptscsih mptbase ata_generic floppy
irq event stamp: 195724
hardirqs last  enabled at (195723): [<ffffffff814a925c>] restore_args+0x0/0x30
hardirqs last disabled at (195724): [<ffffffff814b0a6a>] apic_timer_interrupt+0x6a/0x80
softirqs last  enabled at (195722): [<ffffffff8103f583>] __do_softirq+0x1df/0x276
softirqs last disabled at (195717): [<ffffffff8103f852>] irq_exit+0x53/0x9a
CPU: 0 PID: 46 Comm: kworker/0:2 Not tainted 3.13.0-rc3-branch-dros_testing+ #4
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
Workqueue: rpciod rpc_async_schedule [sunrpc]
task: ffff8800799c4260 ti: ffff880079002000 task.ti: ffff880079002000
RIP: 0010:[<ffffffffa0064fd4>]  [<ffffffffa0064fd4>] __rpc_execute+0x8a/0x362 [sunrpc]
RSP: 0018:ffff880079003d18  EFLAGS: 00000246
RAX: 0000000000000005 RBX: 0000000000000007 RCX: 0000000000000007
RDX: 0000000000000007 RSI: ffff88007aecbae8 RDI: ffff8800783d8900
RBP: ffff880079003d78 R08: ffff88006e30e9f8 R09: ffffffffa005a3d7
R10: ffff88006e30e7b0 R11: ffff8800783d8900 R12: ffffffffa006675e
R13: ffff880079003ce8 R14: ffff88006e30e7b0 R15: ffff8800783d8900
FS:  0000000000000000(0000) GS:ffff88007f200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3072333000 CR3: 0000000001a0b000 CR4: 00000000001407f0
Stack:
 ffff880079003d98 0000000000000246 0000000000000000 ffff88007a9a4830
 ffff880000000000 ffffffff81073f47 ffff88007f212b00 ffff8800799c4260
 ffff8800783d8988 ffff88007f212b00 ffffe8ffff604800 0000000000000000
Call Trace:
 [<ffffffff81073f47>] ? trace_hardirqs_on_caller+0x145/0x1a1
 [<ffffffffa00652d3>] rpc_async_schedule+0x27/0x32 [sunrpc]
 [<ffffffff81052974>] process_one_work+0x211/0x3a5
 [<ffffffff810528d5>] ? process_one_work+0x172/0x3a5
 [<ffffffff81052eeb>] worker_thread+0x134/0x202
 [<ffffffff81052db7>] ? rescuer_thread+0x280/0x280
 [<ffffffff81052db7>] ? rescuer_thread+0x280/0x280
 [<ffffffff810584a0>] kthread+0xc9/0xd1
 [<ffffffff810583d7>] ? __kthread_parkme+0x61/0x61
 [<ffffffff814afd6c>] ret_from_fork+0x7c/0xb0
 [<ffffffff810583d7>] ? __kthread_parkme+0x61/0x61
Code: e8 87 63 fd e0 c6 05 10 dd 01 00 01 48 8b 43 70 4c 8d 6b 70 45 31 e4 a8 02 0f 85 d5 02 00 00 4c 8b 7b 48 48 c7 43 48 00 00 00 00 <4c> 8b 4b 50 4d 85 ff 75 0c 4d 85 c9 4d 89 cf 0f 84 32 01 00 00

And the output of "rpcdebug -m rpc -s all":

RPC:    61 call_refresh (status 0)
RPC:    61 call_refresh (status 0)
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0
RPC:    61 call_refreshresult (status 0)
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0
RPC:    61 call_refreshresult (status 0)
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0
RPC:    61 call_refresh (status 0)
RPC:    61 call_refreshresult (status 0)
RPC:    61 call_refresh (status 0)
RPC:    61 call_refresh (status 0)
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0
RPC:    61 call_refreshresult (status 0)
RPC:    61 call_refresh (status 0)
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0
RPC:    61 call_refresh (status 0)
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0
RPC:    61 call_refreshresult (status 0)
RPC:    61 call_refresh (status 0)
RPC:    61 call_refresh (status 0)
RPC:    61 call_refresh (status 0)
RPC:    61 call_refresh (status 0)
RPC:    61 call_refreshresult (status 0)
RPC:    61 refreshing RPCSEC_GSS cred ffff88007a413cf0

Change-Id: If640c5857d39fd220feaa82c3a85fdd9de98dffc
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dm: wait until embedded kobject is released before destroying a device

commit be35f486108227e10fe5d96fd42fb2b344c59983 upstream.

There may be other parts of the kernel holding a reference on the dm
kobject.  We must wait until all references are dropped before
deallocating the mapped_device structure.

The dm_kobject_release method signals that all references are dropped
via completion.  But dm_kobject_release doesn't free the kobject (which
is embedded in the mapped_device structure).

This is the sequence of operations:
* when destroying a DM device, call kobject_put from dm_sysfs_exit
* wait until all users stop using the kobject, when it happens the
  release method is called
* the release method signals the completion and should return without
  delay
* the dm device removal code that waits on the completion continues
* the dm device removal code drops the dm_mod reference the device had
* the dm device removal code frees the mapped_device structure that
  contains the kobject

Using kobject this way should avoid the module unload race that was
mentioned at the beginning of this thread:
https://lkml.org/lkml/2014/1/4/83

Change-Id: I1ffeea09bef4d4628ce670c7873a8b1b5d04e34c
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dm space map common: make sure new space is used during extend

commit 12c91a5c2d2a8e8cc40a9552313e1e7b0a2d9ee3 upstream.

When extending a low level space map we should update nr_blocks at
the start so the new space is used for the index entries.

Otherwise extend can fail, e.g.: sm_metadata_extend call sequence
that fails:
 -> sm_ll_extend
    -> dm_tm_new_block -> dm_sm_new_block -> sm_bootstrap_new_block
    => returns -ENOSPC because smm->begin == smm->ll.nr_blocks

Change-Id: Ieacca4408a10ad5c1d82590a6142b4412888ce3c
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>