ncpfs: fix rmdir returns Device or resource busy

1d2ef5901483004d74947bbf78d5146c24038fe7 caused a regression in ncpfs such that
directories could no longer be removed.  This was because ncp_rmdir checked
to see if a dentry could be unhashed before allowing it to be removed. Since
1d2ef5901483004d74947bbf78d5146c24038fe7 introduced a change that incremented
dentry->d_count causing it to always be greater than 1 unhash would always
fail.  Thus causing the error path in ncp_rmdir to always be taken.  Removing
this error path is safe as unhashing is still accomplished by calls to dput
from vfs_rmdir.

Signed-off-by: Dave Chiluk <chiluk@canonical.com>
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
USB: f81232: fix device initialisation at open

Do not use uninitialised termios data to determine when to configure the
device at open.

This also prevents stack data from leaking to userspace.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: spcp8x5: fix device initialisation at open

Do not use uninitialised termios data to determine when to configure the
device at open.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: pl2303: fix device initialisation at open

Do not use uninitialised termios data to determine when to configure the
device at open.

This also prevents stack data from leaking to userspace in the OOM error
path.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: chipidea: fix no transceiver case

Since usb phy code does return ERR_PTR() values, make sure that we don't
end up dereferencing them. This is a problem, for example, on platforms
that don't register a phy for chipidea since b7fa5c2a ("usb: phy: return
-ENXIO when PHY layer isn't enabled").

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: chipidea: fix id change handling

Re-enable chipidea irq even if there's no role changing to do. This is
a problem since b183c19f ("USB: chipidea: re-order irq handling to avoid
unhandled irqs"); when it manifests, chipidea irq gets disabled for good.

Cc: stable@vger.kernel.org # v3.7
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mei: init: Flush scheduled work before resetting the device

Flushing pending work items before resetting the device makes more
sense than doing so afterwards. Some of them, like e.g. the NFC
initialization one, find themselves with client IDs changed after
the reset, eventually leading to trigger a client.c:mei_me_cl_by_id()
warning after a few modprobe/rmmod cycles.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mei: nfc: fix nfc device freeing

The nfc_dev is a static variable and is not cleaned properly upon reset
mainly ndev->cl and ndev->cl_info are not set to NULL after freeing which

mei_stop:198: mei_me 0000:00:16.0: stopping the device.
[  404.253427] general protection fault: 0000 [#2] SMP
[  404.253437] Modules linked in: mei_me(-) binfmt_misc snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device edd af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave fuse loop dm_mod hid_generic usbhid hid coretemp acpi_cpufreq mperf kvm_intel kvm crc32c_intel ghash_clmulni_intel aesni_intel ablk_helper cryptd lrw gf128mul snd_hda_codec_hdmi glue_helper aes_x86_64 e1000e snd_hda_intel snd_hda_codec ehci_pci iTCO_wdt iTCO_vendor_support ehci_hcd snd_hwdep xhci_hcd snd_pcm usbcore ptp mei sg microcode snd_timer pps_core i2c_i801 snd pcspkr battery rtc_cmos lpc_ich mfd_core soundcore usb_common snd_page_alloc ac ext3 jbd mbcache drm_kms_helper drm intel_agp i2c_algo_bit intel_gtt i2c_core sd_mod crc_t10dif thermal fan video button processor thermal_sys hwmon ahci libahci libata scsi_mod [last unloaded: mei_me]
[  404.253591] CPU: 0 PID: 5551 Comm: modprobe Tainted: G      D W    3.10.0-rc3 #1
[  404.253611] task: ffff880143cd8300 ti: ffff880144a2a000 task.ti: ffff880144a2a000
[  404.253619] RIP: 0010:[<ffffffff81334e5d>]  [<ffffffff81334e5d>] device_del+0x1d/0x1d0
[  404.253638] RSP: 0018:ffff880144a2bcf8  EFLAGS: 00010206
[  404.253645] RAX: 2020302e30202030 RBX: ffff880144fdb000 RCX: 0000000000000086
[  404.253652] RDX: 0000000000000001 RSI: 0000000000000086 RDI: ffff880144fdb000
[  404.253659] RBP: ffff880144a2bd18 R08: 0000000000000651 R09: 0000000000000006
[  404.253666] R10: 0000000000000651 R11: 0000000000000006 R12: ffff880144fdb000
[  404.253673] R13: ffff880149371098 R14: ffff880144482c00 R15: ffffffffa04710e0
[  404.253681] FS:  00007f251c59a700(0000) GS:ffff88014e200000(0000) knlGS:0000000000000000
[  404.253689] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  404.253696] CR2: ffffffffff600400 CR3: 0000000145319000 CR4: 00000000001407f0
[  404.253703] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  404.253710] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  404.253716] Stack:
[  404.253720]  ffff880144fdb000 ffff880143ffe000 ffff880149371098 ffffffffa0471000
[  404.253732]  ffff880144a2bd38 ffffffff8133502d ffff88014e20cf48 ffff880143ffe1d8
[  404.253744]  ffff880144a2bd48 ffffffffa02a4749 ffff880144a2bd58 ffffffffa02a4ba1
[  404.253755] Call Trace:
[  404.253766]  [<ffffffff8133502d>] device_unregister+0x1d/0x60
[  404.253787]  [<ffffffffa02a4749>] mei_cl_remove_device+0x9/0x10 [mei]
[  404.253804]  [<ffffffffa02a4ba1>] mei_nfc_host_exit+0x21/0x30 [mei]
[  404.253819]  [<ffffffffa029c2dd>] mei_stop+0x3d/0x90 [mei]
[  404.253830]  [<ffffffffa046e220>] mei_me_remove+0x60/0xe0 [mei_me]
[  404.253843]  [<ffffffff81278f37>] pci_device_remove+0x37/0xb0
[  404.253855]  [<ffffffff81337c68>] __device_release_driver+0x98/0x100
[  404.253865]  [<ffffffff81337d80>] driver_detach+0xb0/0xc0
[  404.253876]  [<ffffffff81336b4f>] bus_remove_driver+0x8f/0x120
[  404.253891]  [<ffffffff81075990>] ? try_to_wake_up+0x2b0/0x2b0
[  404.253903]  [<ffffffff81338a48>] driver_unregister+0x58/0x90
[  404.253913]  [<ffffffff8127906b>] pci_unregister_driver+0x2b/0xb0
[  404.253924]  [<ffffffffa046f244>] mei_me_driver_exit+0x10/0xdcc [mei_me]
[  404.253936]  [<ffffffff810a50d8>] SyS_delete_module+0x198/0x2b0
[  404.253949]  [<ffffffff814850d9>] ? do_page_fault+0x9/0x10
[  404.253961]  [<ffffffff81489692>] system_call_fastpath+0x16/0x1b
[  404.253967] Code: 41 5c 41 5d 41 5e 41 5f c9 c3 0f 1f 40 00 55 48 89 e5 41 56 41 55 41 54 49 89 fc 53 48 8b 87 88 00 00 00 4c 8b 37 48 85 c0 74 18 <48> 8b 78 78 4c 89 e2 be 02 00 00 00 48 81 c7 f8 00 00 00 e8 3b
[  404.254048] RIP  [<ffffffff81334e5d>] device_del+0x1d/0x1d0

Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mei: me: clear interrupts on the resume path

We need to clear pending interrupts on the resume
path. This brings the device into defined state
before starting the reset flow

This should solve suspend/resume issues:

mei_me : wait hw ready failed. status = 0x0
mei_me : version message write failed

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xfs: don't emit v5 superblock warnings on write

We write the superblock every 30s or so which results in the
verifier being called. Right now that results in this output
every 30s:

XFS (vda): Version 5 superblock detected. This kernel has EXPERIMENTAL support enabled!
Use of these features in this kernel is at your own risk!

And spamming the logs.

We don't need to check for whether we support v5 superblocks or
whether there are feature bits we don't support set as these are
only relevant when we first mount the filesytem. i.e. on superblock
read. Hence for the write verification we can just skip all the
checks (and hence verbose output) altogether.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

(cherry picked from commit 34510185abeaa5be9b178a41c0a03d30aec3db7e)
xfs: fix implicit padding in directory and attr CRC formats

Michael L. Semon has been testing CRC patches on a 32 bit system and
been seeing assert failures in the directory code from xfs/080.
Thanks to Michael's heroic efforts with printk debugging, we found
that the problem was that the last free space being left in the
directory structure was too small to fit a unused tag structure and
it was being corrupted and attempting to log a region out of bounds.
Hence the assert failure looked something like:

.....
#5 calling xfs_dir2_data_log_unused() 36 32
#1 4092 4095 4096
#2 8182 8183 4096
XFS: Assertion failed: first <= last && last < BBTOB(bp->b_length), file: fs/xfs/xfs_trans_buf.c, line: 568

Where #1 showed the first region of the dup being logged (i.e. the
last 4 bytes of a directory buffer) and #2 shows the corrupt values
being calculated from the length of the dup entry which overflowed
the size of the buffer.

It turns out that the problem was not in the logging code, nor in
the freespace handling code. It is an initial condition bug that
only shows up on 32 bit systems. When a new buffer is initialised,
where's the freespace that is set up:

[  172.316249] calling xfs_dir2_leaf_addname() from xfs_dir_createname()
[  172.316346] #9 calling xfs_dir2_data_log_unused()
[  172.316351] #1 calling xfs_trans_log_buf() 60 63 4096
[  172.316353] #2 calling xfs_trans_log_buf() 4094 4095 4096

Note the offset of the first region being logged? It's 60 bytes into
the buffer. Once I saw that, I pretty much knew that the bug was
going to be caused by this.

Essentially, all direct entries are rounded to 8 bytes in length,
and all entries start with an 8 byte alignment. This means that we
can decode inplace as variables are naturally aligned. With the
directory data supposedly starting on a 8 byte boundary, and all
entries padded to 8 bytes, the minimum freespace in a directory
block is supposed to be 8 bytes, which is large enough to fit a
unused data entry structure (6 bytes in size). The fact we only have
4 bytes of free space indicates a directory data block alignment
problem.

And what do you know - there's an implicit hole in the directory
data block header for the CRC format, which means the header is 60
byte on 32 bit intel systems and 64 bytes on 64 bit systems. Needs
padding. And while looking at the structures, I found the same
problem in the attr leaf header. Fix them both.

Note that this only affects 32 bit systems with CRCs enabled.
Everything else is just fine. Note that CRC enabled filesystems created
before this fix on such systems will not be readable with this fix
applied.

Reported-by: Michael L. Semon <mlsemon35@gmail.com>
Debugged-by: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

(cherry picked from commit 8a1fd2950e1fe267e11fc8c85dcaa6b023b51b60)
xfs: ensure btree root split sets blkno correctly

For CRC enabled filesystems, the BMBT is rooted in an inode, so it
passes through a different code path on root splits than the
freespace and inode btrees. This is much less traversed by xfstests
than the other trees. When testing on a 1k block size filesystem,
I've been seeing ASSERT failures in generic/234 like:

XFS: Assertion failed: cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_private.b.allocated == 0, file: fs/xfs/xfs_btree.c, line: 317

which are generally preceded by a lblock check failure. I noticed
this in the bmbt stats:

$ pminfo -f xfs.btree.block_map

xfs.btree.block_map.lookup
    value 39135

xfs.btree.block_map.compare
    value 268432

xfs.btree.block_map.insrec
    value 15786

xfs.btree.block_map.delrec
    value 13884

xfs.btree.block_map.newroot
    value 2

xfs.btree.block_map.killroot
    value 0
.....

Very little coverage of root splits and merges. Indeed, on a 4k
filesystem, block_map.newroot and block_map.killroot are both zero.
i.e. the code is not exercised at all, and it's the only generic
btree infrastructure operation that is not exercised by a default run
of xfstests.

Turns out that on a 1k filesystem, generic/234 accounts for one of
those two root splits, and that is somewhat of a smoking gun. In
fact, it's the same problem we saw in the directory/attr code where
headers are memcpy()d from one block to another without updating the
self describing metadata.

Simple fix - when copying the header out of the root block, make
sure the block number is updated correctly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

(cherry picked from commit ade1335afef556df6538eb02e8c0dc91fbd9cc37)
xfs: don't shutdown log recovery on validation errors

Unfortunately, we cannot guarantee that items logged multiple times
and replayed by log recovery do not take objects back in time. When
they are taken back in time, the go into an intermediate state which
is corrupt, and hence verification that occurs on this intermediate
state causes log recovery to abort with a corruption shutdown.

Instead of causing a shutdown and unmountable filesystem, don't
verify post-recovery items before they are written to disk. This is
less than optimal, but there is no way to detect this issue for
non-CRC filesystems If log recovery successfully completes, this
will be undone and the object will be consistent by subsequent
transactions that are replayed, so in most cases we don't need to
take drastic action.

For CRC enabled filesystems, leave the verifiers in place - we need
to call them to recalculate the CRCs on the objects anyway. This
recovery problem can be solved for such filesystems - we have a LSN
stamped in all metadata at writeback time that we can to determine
whether the item should be replayed or not. This is a separate piece
of work, so is not addressed by this patch.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

(cherry picked from commit 9222a9cf86c0d64ffbedf567412b55da18763aa3)
fput: task_work_add() can fail if the caller has passed exit_task_work()

fput() assumes that it can't be called after exit_task_work() but
this is not true, for example free_ipc_ns()->shm_destroy() can do
this. In this case fput() silently leaks the file.

Change it to fallback to delayed_fput_work if task_work_add() fails.
The patch looks complicated but it is not, it changes the code from

	if (PF_KTHREAD) {
		schedule_work(...);
		return;
	}
	task_work_add(...)

to
	if (!PF_KTHREAD) {
		if (!task_work_add(...))
			return;
		/* fallback */
	}
	schedule_work(...);

As for shm_destroy() in particular, we could make another fix but I
think this change makes sense anyway. There could be another similar
user, it is not safe to assume that task_work_add() can't fail.

Reported-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
move exit_task_namespaces() outside of exit_notify()

exit_notify() does exit_task_namespaces() after
forget_original_parent(). This was needed to ensure that ->nsproxy
can't be cleared prematurely, an exiting child we are going to
reparent can do do_notify_parent() and use the parent's (ours) pid_ns.

However, after 32084504 "pidns: use task_active_pid_ns in
do_notify_parent" ->nsproxy != NULL is no longer needed, we rely
on task_active_pid_ns().

Move exit_task_namespaces() from exit_notify() to do_exit(), after
exit_fs() and before exit_task_work().

This solves the problem reported by Andrey, free_ipc_ns()->shm_destroy()
does fput() which needs task_work_add().

Note: this particular problem can be fixed if we change fput(), and
that change makes sense anyway. But there is another reason to move
the callsite. The original reason for exit_task_namespaces() from
the middle of exit_notify() was subtle and it has already gone away,
now this looks confusing. And this allows us do simplify exit_notify(),
we can avoid unlock/lock(tasklist) and we can use ->exit_state instead
of PF_EXITING in forget_original_parent().

Reported-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
use can_lookup() instead of direct checks of ->i_op->lookup

a couple of places got missed back when Linus has introduced that one...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
snd_pcm_link(): fix a leak...

in case when snd_pcm_stream_linked(substream) is true, we end up leaking
group.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
powerpc: Fix stack overflow crash in resume_kernel when ftracing

It's possible for us to crash when running with ftrace enabled, eg:

  Bad kernel stack pointer bffffd12 at c00000000000a454
  cpu 0x3: Vector: 300 (Data Access) at [c00000000ffe3d40]
      pc: c00000000000a454: resume_kernel+0x34/0x60
      lr: c00000000000335c: performance_monitor_common+0x15c/0x180
      sp: bffffd12
     msr: 8000000000001032
     dar: bffffd12
   dsisr: 42000000

If we look at current's stack (paca->__current->stack) we see it is
equal to c0000002ecab0000. Our stack is 16K, and comparing to
paca->kstack (c0000002ecab3e30) we can see that we have overflowed our
kernel stack. This leads to us writing over our struct thread_info, and
in this case we have corrupted thread_info->flags and set
_TIF_EMULATE_STACK_STORE.

Dumping the stack we see:

  3:mon> t c0000002ecab0000
  [c0000002ecab0000] c00000000002131c .performance_monitor_exception+0x5c/0x70
  [c0000002ecab0080] c00000000000335c performance_monitor_common+0x15c/0x180
  --- Exception: f01 (Performance Monitor) at c0000000000fb2ec .trace_hardirqs_off+0x1c/0x30
  [c0000002ecab0370] c00000000016fdb0 .trace_graph_entry+0xb0/0x280 (unreliable)
  [c0000002ecab0410] c00000000003d038 .prepare_ftrace_return+0x98/0x130
  [c0000002ecab04b0] c00000000000a920 .ftrace_graph_caller+0x14/0x28
  [c0000002ecab0520] c0000000000d6b58 .idle_cpu+0x18/0x90
  [c0000002ecab05a0] c00000000000a934 .return_to_handler+0x0/0x34
  [c0000002ecab0620] c00000000001e660 .timer_interrupt+0x160/0x300
  [c0000002ecab06d0] c0000000000025dc decrementer_common+0x15c/0x180
  --- Exception: 901 (Decrementer) at c0000000000104d4 .arch_local_irq_restore+0x74/0xa0
  [c0000002ecab09c0] c0000000000fe044 .trace_hardirqs_on+0x14/0x30 (unreliable)
  [c0000002ecab0fb0] c00000000016fe3c .trace_graph_entry+0x13c/0x280
  [c0000002ecab1050] c00000000003d038 .prepare_ftrace_return+0x98/0x130
  [c0000002ecab10f0] c00000000000a920 .ftrace_graph_caller+0x14/0x28
  [c0000002ecab1160] c0000000000161f0 .__ppc64_runlatch_on+0x10/0x40
  [c0000002ecab11d0] c00000000000a934 .return_to_handler+0x0/0x34
  --- Exception: 901 (Decrementer) at c0000000000104d4 .arch_local_irq_restore+0x74/0xa0

  ... and so on

__ppc64_runlatch_on() is called from RUNLATCH_ON in the exception entry
path. At that point the irq state is not consistent, ie. interrupts are
hard disabled (by the exception entry), but the paca soft-enabled flag
may be out of sync.

This leads to the local_irq_restore() in trace_graph_entry() actually
enabling interrupts, which we do not want. Because we have not yet
reprogrammed the decrementer we immediately take another decrementer
exception, and recurse.

The fix is twofold. Firstly make sure we call DISABLE_INTS before
calling RUNLATCH_ON. The badly named DISABLE_INTS actually reconciles
the irq state in the paca with the hardware, making it safe again to
call local_irq_save/restore().

Although that should be sufficient to fix the bug, we also mark the
runlatch routines as notrace. They are called very early in the
exception entry and we are asking for trouble tracing them. They are
also fairly uninteresting and tracing them just adds unnecessary
overhead.

[ This regression was introduced by fe1952fc0afb9a2e4c79f103c08aef5d13db1873
  "powerpc: Rework runlatch code" by myself --BenH
]

CC: <stable@vger.kernel.org> [v3.4+]
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
powerpc: Fix emulation of illegal instructions on PowerNV platform

Normally, the kernel emulates a few instructions that are unimplemented
on some processors (e.g. the old dcba instruction), or privileged (e.g.
mfpvr).  The emulation of unimplemented instructions is currently not
working on the PowerNV platform.  The reason is that on these machines,
unimplemented and illegal instructions cause a hypervisor emulation
assist interrupt, rather than a program interrupt as on older CPUs.
Our vector for the emulation assist interrupt just calls
program_check_exception() directly, without setting the bit in SRR1
that indicates an illegal instruction interrupt.  This fixes it by
making the emulation assist interrupt set that bit before calling
program_check_interrupt().  With this, old programs that use no-longer
implemented instructions such as dcba now work again.

CC: <stable@vger.kernel.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
powerpc: Fix missing/delayed calls to irq_work

When replaying interrupts (as a result of the interrupt occurring
while soft-disabled), in the case of the decrementer, we are exclusively
testing for a pending timer target. However we also use decrementer
interrupts to trigger the new "irq_work", which in this case would
be missed.

This change the logic to force a replay in both cases of a timer
boundary reached and a decrementer interrupt having actually occurred
while disabled. The former test is still useful to catch cases where
a CPU having been hard-disabled for a long time completely misses the
interrupt due to a decrementer rollover.

CC: <stable@vger.kernel.org> [v3.4+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>