Allow locks_mandatory_area() to handle file-private locks correctly.
If there is a file-private lock set on an open file and we're doing I/O
via the same, then that should not cause anything to block.

Handle this by first doing a non-blocking FL_ACCESS check for a
file-private lock, and then fall back to checking for a classic POSIX
lock (and possibly blocking).

Note that this approach is subject to the same races that have always
plagued mandatory locking on Linux.
Reported-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

As Trond pointed out, you can currently deadlock yourself by setting a
file-private lock on a file that requires mandatory locking and then
trying to do I/O on it.

Avoid this problem by plumbing some knowledge of file-private locks into
the mandatory locking code. In order to do this, we must pass down
information about the struct file that's being used to
locks_verify_locked.
Reported-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>

Neil Brown suggested potentially overloading the l_pid value as a "lock
context" field for file-private locks. While I don't think we will
probably want to do that here, it's probably a good idea to ensure that
in the future we could extend this API without breaking existing
callers.

Typically the l_pid value is ignored for incoming struct flock
arguments, serving mainly as a place to return the pid of the owner if
there is a conflicting lock. For file-private locks, require that it
currently be set to 0 and return EINVAL if it isn't. If we eventually
want to make a non-zero l_pid mean something, then this will help ensure
that we don't break legacy programs that are using file-private locks.

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

Due to some unfortunate history, POSIX locks have very strange and
unhelpful semantics. The thing that usually catches people by surprise
is that they are dropped whenever the process closes any file descriptor
associated with the inode.

This is extremely problematic for people developing file servers that
need to implement byte-range locks. Developers often need a "lock
management" facility to ensure that file descriptors are not closed
until all of the locks associated with the inode are finished.

Additionally, "classic" POSIX locks are owned by the process. Locks
taken between threads within the same process won't conflict with one
another, which renders them useless for synchronization between threads.

This patchset adds a new type of lock that attempts to address these
issues. These locks conflict with classic POSIX read/write locks, but
have semantics that are more like BSD locks with respect to inheritance
and behavior on close.

This is implemented primarily by changing how fl_owner field is set for
these locks. Instead of having them owned by the files_struct of the
process, they are instead owned by the filp on which they were acquired.
Thus, they are inherited across fork() and are only released when the
last reference to a filp is put.

These new semantics prevent them from being merged with classic POSIX
locks, even if they are acquired by the same process. These locks will
also conflict with classic POSIX locks even if they are acquired by
the same process or on the same file descriptor.

The new locks are managed using a new set of cmd values to the fcntl()
syscall. The initial implementation of this converts these values to
"classic" cmd values at a fairly high level, and the details are not
exposed to the underlying filesystem. We may eventually want to push
this handing out to the lower filesystem code but for now I don't
see any need for it.

Also, note that with this implementation the new cmd values are only
available via fcntl64() on 32-bit arches. There's little need to
add support for legacy apps on a new interface like this.
Signed-off-by: Jeff Layton <jlayton@redhat.com>

It's not really feasible to do deadlock detection with FL_FILE_PVT
locks since they aren't owned by a single task, per-se. Deadlock
detection also tends to be rather expensive so just skip it for
these sorts of locks.

Also, add a FIXME comment about adding more limited deadlock detection
that just applies to ro -> rw upgrades, per Andy's request.

Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

Once we introduce file private locks, we'll need to know what cmd value
was used, as that affects the ownership and whether a conflict would
arise.
Signed-off-by: Jeff Layton <jlayton@redhat.com>

FL_FILE_PVT locks are no longer tied to a particular pid, and are
instead inheritable by child processes. Report a l_pid of '-1' for
these sorts of locks since the pid is somewhat meaningless for them.

This precedent comes from FreeBSD. There, POSIX and flock() locks can
conflict with one another. If fcntl(F_GETLK, ...) returns a lock set
with flock() then the l_pid member cannot be a process ID because the
lock is not held by a process as such.
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

In a later patch, we'll be adding a new type of lock that's owned by
the struct file instead of the files_struct. Those sorts of locks
will be flagged with a new FL_FILE_PVT flag.

Report these types of locks as "FLPVT" in /proc/locks to distinguish
them from "classic" POSIX locks.
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

This function currently removes leases in addition to flock locks and in
a later patch we'll have it deal with file-private locks too. Rename it
to locks_remove_file to indicate that it removes locks that are
associated with a particular struct file, and not just flock locks.
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

Move this check into flock64_to_posix_lock instead of duplicating it in
two places. This also fixes a minor wart in the code where we continue
referring to the struct flock after converting it to struct file_lock.
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

In the 32-bit case fcntl assigns the 64-bit f_pos and i_size to a 32-bit
off_t.

The existing range checks also seem to depend on signed arithmetic
wrapping when it overflows.  In practice maybe that works, but we can be
more careful.  That also allows us to make a more reliable distinction
between -EINVAL and -EOVERFLOW.

Note that in the 32-bit case SEEK_CUR or SEEK_END might allow the caller
to set a lock with starting point no longer representable as a 32-bit
value.  We could return -EOVERFLOW in such cases, but the locks code is
capable of handling such ranges, so we choose to be lenient here.  The
only problem is that subsequent GETLK calls on such a lock will fail
with EOVERFLOW.

While we're here, do some cleanup including consolidating code for the
flock and flock64 cases.
Signed-off-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

A leftover lock on the list is surely a sign of a problem of some sort,
but it's not necessarily a reason to panic the box. Instead, just log a
warning with some info about the lock, and then delete it like we would
any other lock.

In the event that the filesystem declares a ->lock f_op, we may end up
leaking something, but that's generally preferable to an immediate
panic.
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

...to make sparse happy.
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

It's best to let the compiler decide that.
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

As Al Viro points out, there is an unlikely, but possible race between
opening a file and setting a lease on it. generic_add_lease is done with
the i_lock held, but the inode->i_flock check in break_lease is
lockless. It's possible for another task doing an open to do the entire
pathwalk and call break_lease between the point where generic_add_lease
checks for a conflicting open and adds the lease to the list. If this
occurs, we can end up with a lease set on the file with a conflicting
open.

To guard against that, check again for a conflicting open after adding
the lease to the i_flock list. If the above race occurs, then we can
simply unwind the lease setting and return -EAGAIN.

Because we take dentry references and acquire write access on the file
before calling break_lease, we know that if the i_flock list is empty
when the open caller goes to check it then the necessary refcounts have
already been incremented. Thus the additional check for a conflicting
open will see that there is one and the setlease call will fail.

Cc: Bruce Fields <bfields@fieldses.org>
Cc: David Howells <dhowells@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@fieldses.org>

Both Bruce and I have done a fair bit of work in these files recently,
and would like to be notified if anyone is proposing changes to it.

Also, Matthew is no longer interested in maintaining this code, so
remove him.

Cc: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>

Pull parisc updates from Helge Deller:
 "The three major changes in this patchset is a implementation for
  flexible userspace memory maps, cache-flushing fixes (again), and a
  long-discussed ABI change to make EWOULDBLOCK the same value as
  EAGAIN.

  parisc has been the only platform where we had EWOULDBLOCK != EAGAIN
  to keep HP-UX compatibility.  Since we will probably never implement
  full HP-UX support, we prefer to drop this compatibility to make it
  easier for us with Linux userspace programs which mostly never checked
  for both values.  We don't expect major fall-outs because of this
  change, and if we face some, we will simply rebuild the necessary
  applications in the debian archives"

* 'parisc-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: add flexible mmap memory layout support
  parisc: Make EWOULDBLOCK be equal to EAGAIN on parisc
  parisc: convert uapi/asm/stat.h to use native types only
  parisc: wire up sched_setattr and sched_getattr
  parisc: fix cache-flushing
  parisc/sti_console: prefer Linux fonts over built-in ROM fonts

HPFS needs to load 4 consecutive 512-byte sectors when accessing the
directory nodes or bitmaps.  We can't switch to 2048-byte block size
because files are allocated in the units of 512-byte sectors.

Previously, the driver would allocate a 2048-byte area using kmalloc,
copy the data from four buffers to this area and eventually copy them
back if they were modified.

In the current implementation of the buffer cache, buffers are allocated
in the pagecache.  That means that 4 consecutive 512-byte buffers are
stored in consecutive areas in the kernel address space.  So, we don't
need to allocate extra memory and copy the content of the buffers there.

This patch optimizes the code to avoid copying the buffers.  It checks
if the four buffers are stored in contiguous memory - if they are not,
it falls back to allocating a 2048-byte area and copying data there.
Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Previously, hpfs scanned all bitmaps each time the user asked for free
space using statfs.  This patch changes it so that hpfs scans the
bitmaps only once, remembes the free space and on next invocation of
statfs it returns the value instantly.

New versions of wine are hammering on the statfs syscall very heavily,
making some games unplayable when they're stored on hpfs, with load
times in minutes.

This should be backported to the stable kernels because it fixes
user-visible problem (excessive level load times in wine).
Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add support for the flexible mmap memory layout (as described in
http://lwn.net/Articles/91829). This is especially very interesting on
parisc since we currently only support 32bit userspace (even with a
64bit Linux kernel).
Signed-off-by: Helge Deller <deller@gmx.de>

On Linux, only parisc uses a different value for EWOULDBLOCK which
causes a lot of troubles for applications not checking for both values.
Since the hpux compat is long dead, make EWOULDBLOCK behave the same as
all other architectures.
Signed-off-by: Guy Martin <gmsoft@tuxicoman.be>
Signed-off-by: Helge Deller <deller@gmx.de>

The stat.h header file is exported to userspace. Some userspace
applications failed to compile due to missing/unknown types, so we
better convert it to use native types only (like it's done on other
architectures too).
Signed-off-by: Helge Deller <deller@gmx.de>

Signed-off-by: Helge Deller <deller@gmx.de>

This commit:
f8dae006: parisc: Ensure full cache coherency for kmap/kunmap
caused negative caching side-effects, e.g. hanging processes with expect and
too many inequivalent alias messages from flush_dcache_page() on Debian 5 systems.

This patch now partly reverts it and has been in production use on our debian buildd
makeservers since a week without any major problems.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Helge Deller <deller@gmx.de>

The built-in ROM fonts lack many necessary ASCII characters, which is
why it makes sens to prefer the Linux fonts instead if they are
available.  This makes consoles on STI graphics cards which are not
supported by the stifb driver (e.g. Visualize FXe) looks much nicer.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13

Pull hwmon kconfig fixes from Jean Delvare.

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  hwmon: Fix SENSORS_TMP102 dependencies to eliminate build errors
  hwmon: Fix SENSORS_LM75 dependencies to eliminate build errors

Pull SLAB changes from Pekka Enberg:
 "Random bug fixes that have accumulated in my inbox over the past few
  months"

* 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
  mm: Fix warning on make htmldocs caused by slab.c
  mm: slub: work around unneeded lockdep warning
  mm: sl[uo]b: fix misleading comments
  slub: Fix possible format string bug.
  slub: use lockdep_assert_held
  slub: Fix calculation of cpu slabs
  slab.h: remove duplicate kmalloc declaration and fix kernel-doc warnings

Pull turbostat updates from Len Brown.

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  tools/power turbostat: introduce -s to dump counters
  tools/power turbostat: remove unused command line option
  turbostat: Add option to report joules consumed per sample
  turbostat: run on HSX
  turbostat: Add a .gitignore to ignore the compiled turbostat binary
  turbostat: Clean up error handling; disambiguate error messages; use err and errx
  turbostat: Factor out common function to open file and exit on failure
  turbostat: Add a helper to parse a single int out of a file
  turbostat: Check return value of fscanf
  turbostat: Use GCC's CPUID functions to support PIC
  turbostat: Don't attempt to printf an off_t with %zx
  turbostat: Don't put unprocessed uapi headers in the include path

Pull ARM SoC fixes from Olof Johansson:
 "Here's a set of patches for (hopefully) -rc1.  Some of them are fixes,
  but a good number of them also do things such as enable new drivers in
  the defconfigs for platforms that have such devices, increases
  coverage of the multiplatform defconfig and some DTS changes that
  plumbs up some of the devices that now have bindings and driver
  support.

  The commit dates are recent; we've mostly collected these fixes in the
  last few days but I also had to rebuild the branch yesterday to sort
  out some internal conflicts which reset the timestamps.  The changes
  should have been tested by each platform maintainer already (and few
  of them have cross-platform impact) so I'm personally not too
  concerned by it at this time"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (23 commits)
  ARM: multi_v7_defconfig: remove redundant entries and re-enable TI_EDMA
  ARM: multi_v7_defconfig: add mvebu drivers
  clocksource: kona: Add basic use of external clock
  drivers: bus: fix CCI driver kcalloc call parameters swap
  ARM: dts: bcm28155-ap: Fix Card Detection GPIO
  ARM: multi_v7_defconfig: Select CONFIG_AT803X_PHY
  ARM: keystone: config: fix build warning when CONFIG_DMADEVICES is not set
  MAINTAINERS: ARM: SiRF: use regex patterns to involve all SiRF drivers
  ARM: dts: zynq: Add SDHCI nodes
  ARM: hisi: don't select SMP
  ARM: tegra: rebuild tegra_defconfig to add DEBUG_FS
  ARM: multi_v7: copy most options from tegra_defconfig
  ARM: iop32x: fix power off handling for the EM7210 board
  ARM: integrator: restore static map on the CP
  ARM: msm_defconfig: Enable MSM clock drivers
  ARM: dts: msm: Add clock controller nodes and hook into uart
  ARM: OMAP4+: move errata initialization to omap4_pm_init_early
  ARM: OMAP4460: cpuidle: Extend PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD on cpuidle
  ARM: mvebu: fix compilation warning on Armada 370 (i.e. non-SMP)
  ARM: shmobile: r8a7790.dtsi: ficx i2c[0-3] clock reference
  ...

Similar to what was done for the lm75 driver.

Add depends on THERMAL since that is what provides the
register/unregister functions above, but only if THERMAL_OF was
selected as this is an optional feature of the driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Based on an earlier attempt by Randy Dunlap.

Fix SENSORS_LM75 dependencies to eliminate build errors:

drivers/built-in.o: In function `lm75_remove':
lm75.c:(.text+0x12bd8c): undefined reference to `thermal_zone_of_sensor_unregister'
drivers/built-in.o: In function `lm75_probe':
lm75.c:(.text+0x12c123): undefined reference to `thermal_zone_of_sensor_register'

Add depends on THERMAL since that is what provides the
register/unregister functions above, but only if THERMAL_OF was
selected as this is an optional feature of the driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>

The new option allows just run turbostat and get dump of counter values. It's
useful when we have something more than one program to test.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

The -s is not used, let's remove it, and update quick help accordingly.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Pull misc kbuild changes from Michal Marek:
 "The non-critical part of kbuild is small this time:
   - Three fixes for make deb-pkg
   - A new coccinelle check

  One of the deb-pkg fixes is a leftover from the last merge window,
  hence the merge commit"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  deb-pkg: Fix building for MIPS big-endian or ARM OABI
  deb-pkg: Fix cross-building linux-headers package
  scripts: Coccinelle script for pm_runtime_* return checks with IS_ERR_VALUE
  deb-pkg: Inhibit initramfs builders if CONFIG_BLK_DEV_INITRD is not set

Both proc files are writeable and used for configuring cells. But
there is missing correct mode flag for writeable files. Without
this patch both proc files are read only.

[ It turns out they aren't really read-only, since root can write to
  them even if the write bit isn't set due to CAP_DAC_OVERRIDE ]
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With commit d8d14bd0 ("fs/compat: fix lookup_dcookie() parameter
handling") I changed the type of the len parameter of the
lookup_dcookie() syscall.

However I missed that there was still a stale declaration in
arch/tile/..  which now causes a compile error on tile:

  In file included from fs/dcookies.c:28:0:
  include/linux/compat.h:425:17: error: conflicting types for 'compat_sys_lookup_dcookie'
  fs/dcookies.c:207:1: error: conflicting types for 'compat_sys_lookup_dcookie'

Simply remove the declaration in the tile architecture, which is only a
leftover from before the different compat lookup_dcookie() versions have
been merged.  The correct declaration is now in include/linux/compat.h

The build error was reported by Fenguang's build bot.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull cifs fixes from Steve French:
 "A set of cifs fixes (mostly for symlinks, and SMB2 xattrs) and
  cleanups"

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Fix check for regular file in couldbe_mf_symlink()
  [CIFS] Fix SMB2 mounts so they don't try to set or get xattrs via cifs
  CIFS: Cleanup cifs open codepath
  CIFS: Remove extra indentation in cifs_sfu_type
  CIFS: Cleanup cifs_mknod
  CIFS: Cleanup CIFSSMBOpen
  cifs: Add support for follow_link on dfs shares under posix extensions
  cifs: move unix extension call to cifs_query_symlink()
  cifs: Re-order M-F Symlink code
  cifs: Add create MFSymlinks to protocol ops struct
  cifs: use protocol specific call for query_mf_symlink()
  cifs: Rename MF symlink function names
  cifs: Rename and cleanup open_query_close_cifs_symlink()
  cifs: Fix memory leak in cifs_hardlink()

Pull vfs fixes from Al Viro:
 "Several obvious fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Fix mountpoint reference leakage in linkat
  hfsplus: use xattr handlers for removexattr
  Typo in compat_sys_lseek() declaration
  fs/super.c: sync ro remount after blocking writers
  vfs: unexport the getname() symbol