dcache: d_obtain_alias callers don't all want DISCONNECTED

There are a few d_obtain_alias callers that are using it to get the
root of a filesystem which may already have an alias somewhere else.

This is not the same as the filehandle-lookup case, and none of them
actually need DCACHE_DISCONNECTED set.

It isn't really a serious problem, but it would really be clearer if we
reserved DCACHE_DISCONNECTED for those cases where it's actually needed.

In the btrfs case this was causing a spurious printk from
nfsd/nfsfh.c:fh_verify when it found an unexpected DCACHE_DISCONNECTED
dentry.  Josef worked around this by unsetting DCACHE_DISCONNECTED
manually in 3a0dfa6a12e "Btrfs: unset DCACHE_DISCONNECTED when mounting
default subvol", and this replaces that workaround.

Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
dcache: remove unused d_find_alias parameter

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
dcache: d_find_alias needn't recheck IS_ROOT && DCACHE_DISCONNECTED

If we get to this point and discover the dentry is not a root dentry, or
not DCACHE_DISCONNECTED--great, we always prefer that anyway.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
exportfs: update Exporting documentation

Minor documentation updates:
	- refer to d_obtain_alias rather than d_alloc_anon
	- explain when to use d_splice_alias and when
	  d_materialise_unique.
	- cut some details of d_splice_alias/d_materialise_unique
	  implementation.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
dcache: d_splice_alias should detect loops

I believe this can only happen in the case of a corrupted filesystem.
So -EIO looks like the appropriate error.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs: mark __d_obtain_alias static

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
switch iov_iter_get_pages() to passing maximal number of pages

... instead of maximal size.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
6lowpan: Allow 6LoWPAN to be modular

Change config symbol 6LOWPAN from type bool to type tristate, so
6LoWPAN can be built modular, just like IPV6

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
ACPI / hotplug: Check scan handlers in acpi_scan_hot_remove()

When ACPI_HOTPLUG_MEMORY is not configured, memory_device_handler.attach
is not set.  In acpi_scan_attach_handler(), the acpi_device->handler will
not be initialized.

In acpi_scan_hot_remove(), it doesn't check if acpi_device->handler is NULL.
If we do memory hot-remove without ACPI_HOTPLUG_MEMORY configured, the kernel
will panic.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000088
 IP: [<ffffffff813e318f>] acpi_device_hotplug+0x1d7/0x4c4
 PGD 0
 Oops: 0000 [#1] SMP
 Modules linked in: sd_mod(E) sr_mod(E) cdrom(E) crc_t10dif(E) crct10dif_common(E) ata_piix(E) libata(E)
 CPU: 0 PID: 41 Comm: kworker/u2:1 Tainted: G            E 3.16.0-rc7--3.16-rc7-tangchen+ #20
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
 Workqueue: kacpi_hotplug acpi_hotplug_work_fn
 task: ffff8800182436c0 ti: ffff880018254000 task.ti: ffff880018254000
 RIP: 0010:[<ffffffff813e318f>]  [<ffffffff813e318f>] acpi_device_hotplug+0x1d7/0x4c4
 RSP: 0000:ffff880018257da8  EFLAGS: 00000246
 RAX: 0000000000000000 RBX: ffff88001cd8d800 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff88001e40e6f8 RDI: 0000000000000246
 RBP: ffff880018257df0 R08: 0000000000000096 R09: 00000000000011a0
 R10: 63735f6970636120 R11: 725f746f685f6e61 R12: 0000000000000003
 R13: ffff88001cc1c400 R14: ffff88001e062028 R15: 0000000000000040
 FS:  0000000000000000(0000) GS:ffff88001e400000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000088 CR3: 000000001a9a2000 CR4: 00000000000006f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 0000000000000000 DR7: 0000000000000000
 Stack:
  00000000523cab58 ffff88001cd8d9f8 ffff88001852d480 00000000523cab58
  ffff88001852d480 ffff880018221e40 ffff88001cc1c400 ffff88001cce2d00
  0000000000000040 ffff880018257e08 ffffffff813dc31d ffff88001852d480
 Call Trace:
  [<ffffffff813dc31d>] acpi_hotplug_work_fn+0x1e/0x29
  [<ffffffff8108eefb>] process_one_work+0x17b/0x460
  [<ffffffff8108f69d>] worker_thread+0x11d/0x5b0
  [<ffffffff8108f580>] ? rescuer_thread+0x3a0/0x3a0
  [<ffffffff81096811>] kthread+0xe1/0x100
  [<ffffffff81096730>] ? kthread_create_on_node+0x1a0/0x1a0
  [<ffffffff816cc6bc>] ret_from_fork+0x7c/0xb0
  [<ffffffff81096730>] ? kthread_create_on_node+0x1a0/0x1a0

This patch fixes this problem by checking if acpi_device->handler is NULL
in acpi_scan_hot_remove().

Fixes: d22ddcbc4fb7 (ACPI / hotplug: Add demand_offline hotplug profile flag)
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
[rjw: Subject]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: speedstep-smi: fix decimal printf specifiers

The prefix suggests the number should be printed in hex, so use
the %x specifier to do that. Also, these are 32-bit values,
so drop the l characters.

Signed-off-by: Hans Wennborg <hans@hanshq.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
kbuild: Fix handling of backslashes in *.cmd files

Commit c353acba ("kbuild: make: fix if_changed when command contains
backslashes") attempted to handle backslashes in *.cmd files, but it
only handled double backslashes for some reason. Changing make-cmd to also
handle single backslashes fixes rebuilds with dash, but it breaks bash
again. The reason is that the two shells disagree about the
interpretation of backslash sequences in the echo builtin. The way out
of this is to print the command with printf '%s\n'. While at it,
document what the individual parts of make-cmd do and why.

Reported-and-tested-by: Konstantin Khlebnikov <koct9i@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
kbuild: kselftest - new make target to build and run kernel selftests

Add a new make target "kselftest" to enable kernel testing. This
new target builds and runs kernel selftests. Running as root is
recommended for a complete test run as some tests don't run when
run by non-root user. Build, install, and boot kernel before
running kselftest on it.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Merge branches 'kbuild/kbuild' and 'kbuild/misc' into kbuild/for-next
Revert "drm: drop redundant drm_file->is_master"

This reverts commit 48ba813701eb14b3008edefef4a0789b328e278c.

Thanks to Chris:
"drm_file->is_master is not synomous with having drm_file->master ==
drm_file->minor->master. This is because drm_file->master is the same
for all drm_files of the same generation and so when there is a master,
every drm_file believes itself to be the master. Confusion ensues and
things go pear shaped when one file is closed and there is no master
anymore."

Conflicts:
	drivers/gpu/drm/drm_drv.c
	drivers/gpu/drm/drm_stub.c
Merge branch 'next/fixes-non-critical' into next/cleanup

Merging in the few fixes we had also received, no need to keep those in
a separate branch.

* next/fixes-non-critical:
  drivers: CCI: Correct use of ! and &
  MAINTAINERS: Add sdhci-st file to ARCH/STI architecture
  ARM: EXYNOS: Fix build breakge with PM_SLEEP=n
  ARM: omap2+: gpmc-nand: Use dynamic platform_device_alloc()
  omap16xx: Removes fixme no longer needed in ocpi_enable()
  ARM: dts: OMAP5: Add device nodes for ABB
  ARM: omap2+: usb-tusb6010.c: Cleaning up variable is set more than once

Signed-off-by: Olof Johansson <olof@lixom.net>
cxgb4: Update FW version string to match FW binary version

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
xen-netback: Fix vif->disable handling

In the patch called "xen-netback: Turn off the carrier if the guest is not able
to receive" new branches were introduced to this if statement, risking that a
queue with non-zero id can reenable the disabled interface.

Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>
solos-pci: fix error return code

Convert a zero return value on error to a negative one, as returned
elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>
amd: xgbe: fix duplicate #include of linux/phy.h

The header linux/phy.h was included twice, so delete one of them.

Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
openvswitch: fix duplicate #include headers

The #include headers net/genetlink.h and linux/genetlink.h both were
included twice, so delete each of the duplicate.

Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Cc: Pravin Shelar <pshelar@nicira.com>
Cc: dev@openvswitch.org
Signed-off-by: David S. Miller <davem@davemloft.net>