locks: add missing memory barrier in break_deleg

break_deleg is subject to the same potential race as break_lease. Add
a memory barrier to prevent it.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
locks: set fl_owner for leases back to current->files

This fixes a regression due to commit 130d1f956ab3 (locks: ensure that
fl_owner is always initialized properly in flock and lease codepaths). I
had mistakenly thought that the fl_owner wasn't used in the lease code,
but I missed the place in __break_lease that does use it.

The i_have_this_lease check in generic_add_lease uses it. While I'm not
sure that check is terribly helpful [1], reset it back to using
current->files in order to ensure that there's no behavior change here.

[1]: leases are owned by the file description. It's possible that this
     is a threaded program, and the lease breaker and the task that
     would handle the signal are different, even if they have the same
     file table. So, there is the potential for false positives with
     this check.

Fixes: 130d1f956ab3 (locks: ensure that fl_owner is always initialized properly in flock and lease codepaths)
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
i2c: rk3x: add driver for Rockchip RK3xxx SoC I2C adapter

Driver for the native I2C adapter found in Rockchip RK3xxx SoCs.

Configuration is only possible through devicetree. The driver is
interrupt driven and supports the I2C_M_IGNORE_NAK mangling bit.

Signed-off-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: sunxi: add P2WI DT bindings documentation

P2WI (Push/Pull 2 Wire Interface) is an SMBus like bus used to communicate
with some PMICs (like the AXP221).

Document P2WI DT bindings which are pretty much the same as the one defined
for the marvell's mv64xxx controller.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support

The P2WI controller looks like an SMBus controller which only supports byte
data transfers. But, it differs from standard SMBus protocol on several
aspects:
- it supports only one slave device, and thus drop the address field
- it adds a parity bit every 8bits of data
- only one read access is required to read a byte (instead of a write
  followed by a read access in standard SMBus protocol)
- there's no Ack bit after each byte transfer

This means this bus cannot be used to interface with standard SMBus
devices (the only known device to support this interface is the AXP221
PMIC).
However the P2WI protocol is close enough to SMBus to be integrated in
the I2C subsystem (see this thread [1] for detailed reasons that led to
integrating this driver in the I2C subsystem).

[1] http://www.spinics.net/lists/linux-i2c/msg15066.html

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: sun6i-p2wi: use proper return value in probe

Fixes:
>> drivers/i2c/busses/i2c-sun6i-p2wi.c:243:10: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: rk3x: add NULL entry to the end of_device_id array

drivers/i2c/busses/i2c-rk3x.c:610:69-70: rk3x_i2c_match is not NULL terminated at line 610

Make sure of_device_id tables are NULL terminated
Generated by: /kbuild/src/linux/scripts/coccinelle/misc/of_table.cocci

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c: sun6-p2wi: fix call to snprintf

Fixes possible issue in case pdev name contains formatting characters.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Merge tag 'v3.16-rc1' into i2c/for-next

Merge a stable base (Linux 3.16-rc1)

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
NFSD: Don't hand out delegations for 30 seconds after recalling them.

If nfsd needs to recall a delegation for some reason it implies that there is
contention on the file, so further delegations should not be handed out.

The current code fails to do so, and the result is effectively a
live-lock under some workloads: a client attempting a conflicting
operation on a read-delegated file receives NFS4ERR_DELAY and retries
the operation, but by the time it retries the server may already have
given out another delegation.

We could simply avoid delegations for (say) 30 seconds after any recall, but
this is probably too heavy handed.

We could keep a list of inodes (or inode numbers or filehandles) for recalled
delegations, but that requires memory allocation and searching.

The approach taken here is to use a bloom filter to record the filehandles
which are currently blocked from delegation, and to accept the cost of a few
false positives.

We have 2 bloom filters, each of which is valid for 30 seconds.   When a
delegation is recalled the filehandle is added to one filter and will remain
disabled for between 30 and 60 seconds.

We keep a count of the number of filehandles that have been added, so when
that count is zero we can bypass all other tests.

The bloom filters have 256 bits and 3 hash functions.  This should allow a
couple of dozen blocked  filehandles with minimal false positives.  If many
more filehandles are all blocked at once, behaviour will degrade towards
rejecting all delegations for between 30 and 60 seconds, then resetting and
allowing new delegations.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
NFSD: fix bug for readdir of pseudofs

Commit 561f0ed498ca (nfsd4: allow large readdirs) introduces a bug
about readdir the root of pseudofs.

Call xdr_truncate_encode() revert encoded name when skipping.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
deb-pkg: Fix for relative paths

When $srctree or $objtree are relative paths, we cannot change directory
and refer to them in the same subshell. Do the redirection outside of
the subshell to fix this.

Reported-and-tested-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
kbuild: Fix tar-pkg with relative $(objtree)

Commit 7e1c0477 (kbuild: Use relative path for $(objtree)) assumes that
the build process does not change its working directory. make tar-pkg
was a couterexample, fix this by changing directory only for the tar
command and not for the whole script, which at one point references the
now relative $(objtree).

Reported-and-tested-by: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Documentation: Fix DocBook build with relative $(srctree)

After commits 890676c6 (kbuild: Use relative path when building in the source
tree) and 9da0763b (kbuild: Use relative path when building in a subdir
of the source tree), the $(srctree) variable can be a relative path.
This breaks Documentation/DocBook/media/Makefile, because it tries to
create symlinks from a subdirectory of the object tree to the source
tree. Fix this by using a full path in this case.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
builddeb: fix missing headers in linux-headers package

The kernel headers package (linux-headers) doesn't include several
header files required to build out-of-tree modules.

It makes the package unusable on e.g. ARM architecture:
 /usr/src/linux-headers-3.14.0/arch/arm/include/asm/memory.h:24:25:
 fatal error: mach/memory.h: No such file or directory
 #include <mach/memory.h>
 ^
 compilation terminated.

Signed-off-by: Fathi Boudra <fathi.boudra@linaro.org>
Reviewed-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
kbuild: fix a typo in a kbuild document

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Btrfs: fix deadlocks with trylock on tree nodes

The Btrfs tree trylock function is poorly named.  It always takes
the spinlock and backs off if the blocking lock is held.  This
can lead to surprising lockups because people expect it to really be a
trylock.

This commit makes it a pure trylock, both for the spinlock and the
blocking lock.  It also reworks the nested lock handling slightly to
avoid taking the read lock while a spinning write lock might be held.

Signed-off-by: Chris Mason <clm@fb.com>
Btrfs: remove unused wait queue in struct extent_buffer

The lock_wq wait queue is not used anywhere, therefore just remove it.
On a x86_64 system, this reduced sizeof(struct extent_buffer) from 320
bytes down to 296 bytes, which means a 4Kb page can now be used for
13 extent buffers instead of 12.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Btrfs: make free space cache write out functions more readable

This patch makes the free space cache write out functions more readable,
and beisdes that, it also reduces the stack space that the function --
__btrfs_write_out_cache uses from 194bytes to 144bytes.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Btrfs: fix broken free space cache after the system crashed

When we mounted the filesystem after the crash, we got the following
message:
  BTRFS error (device xxx): block group xxxx has wrong amount of free space
  BTRFS error (device xxx): failed to load free space cache for block group xxx

It is because we didn't update the metadata of the allocated space (in extent
tree) until the file data was written into the disk. During this time, there was
no information about the allocated spaces in either the extent tree nor the
free space cache. when we wrote out the free space cache at this time (commit
transaction), those spaces were lost. In fact, only the free space that is
used to store the file data had this problem, the others didn't because
the metadata of them is updated in the same transaction context.

There are many methods which can fix the above problem
- track the allocated space, and write it out when we write out the free
  space cache
- account the size of the allocated space that is used to store the file
  data, if the size is not zero, don't write out the free space cache.

The first one is complex and may make the performance drop down.
This patch chose the second method, we use a per-block-group variant to
account the size of that allocated space. Besides that, we also introduce
a per-block-group read-write semaphore to avoid the race between
the allocation and the free space cache write out.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>