drivers/char/misc.c:misc_register(): do not loop on misc_list unconditionally

If the minor number is assigned dynamically, there is no need to search
for misc->minor in misc_list, since misc->minor == MISC_DYNAMIC_MINOR.

[akpm@linux-foundation.org: reduce scope of local `c']
Signed-off-by: Dae S. Kim <dae@velatum.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipmi: add options to disable openfirmware and PCI scanning

Add try...  parameters to disable pci and platform (openfirmware) device
scanning for IPMI.  Also add docs for all the try...  parameters.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipmi: add new kernel options to prevent automatic ipmi init

The configuration change building ipmi_si into the kernel precludes the
use of a custom driver that can utilize more than one KCS interface,
multiple IPMBs, and more than one BMC.  This capability is important for
fault-tolerant systems.

Even if the kernel option ipmi_si.trydefaults=0 is specified, ipmi_si
discovers and claims one of the KCS interfaces on a Stratus server.  The
inability to now prevent the kernel from managing this device is a
regression from previous kernels.  The regression breaks a capability
fault-tolerant vendors have relied upon.

To support both ACPI opregion access and the need to avoid activation of
ipmi_si on some platforms, we've added two new kernel options,
ipmi_si.tryacpi and ipmi_si.trydmi be added to prevent ipmi_si from
initializing when these options are set to 0 on the kernel command line.
With these options at the default value of 1, ipmi_si init proceeds
according to the kernel default.

Tested-by: Jim Paradis <jparadis@redhat.com>
Signed-off-by: Robert Evans <Robert.Evans@stratus.com>
Signed-off-by: Jim Paradis <jparadis@redhat.com>
Signed-off-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipmi: remove superfluous kernel/userspace explanation

Given the obvious distinction between kernel and userspace supported
by uapi/, it seems unnecessary to comment on that.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: explain WARN_ON_ONCE() on negative IDs out-of-range ID

Until recently, when an negative ID is specified, idr functions used to
ignore the sign bit and proceeded with the operation with the rest of
bits, which is bizarre and error-prone.  The behavior recently got changed
so that negative IDs are treated as invalid but we're triggering
WARN_ON_ONCE() on negative IDs just in case somebody was depending on the
sign bit being ignored, so that those can be detected and fixed easily.

We only need this for a while.  Explain why WARN_ON_ONCE()s are there and
that they can be removed later.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: implement lookup hint

While idr lookup isn't a particularly heavy operation, it still is too
substantial to use in hot paths without worrying about the performance
implications.  With recent changes, each idr_layer covers 256 slots
which should be enough to cover most use cases with single idr_layer
making lookup hint very attractive.

This patch adds idr->hint which points to the idr_layer which
allocated an ID most recently and the fast path lookup becomes

if (look up target's prefix matches that of the hinted layer)
return hint->ary[ID's offset in the leaf layer];

which can be inlined.

idr->hint is set to the leaf node on idr_fill_slot() and cleared from
free_layer().

[andriy.shevchenko@linux.intel.com: always do slow path when hint is uninitialized]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: add idr_layer->prefix

Add a field which carries the prefix of ID the idr_layer covers.  This
will be used to implement lookup hint.

This patch doesn't make use of the new field and doesn't introduce any
behavior difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: make idr_layer larger

With recent preloading changes, idr no longer keeps full layer cache per
each idr instance (used to be ~6.5k per idr on 64bit) and the previous
patch removed restriction on the bitmap size.  Both now allow us to have
larger layers.

Increase IDR_BITS to 8 regardless of BITS_PER_LONG.  Each layer is
slightly larger than 2k on 64bit and 1k on 32bit and carries 256 entries.
The size isn't too large, especially compared to what we used to waste on
per-idr caches, and 256 entries should be able to serve most use cases
with single layer.  The max tree depth is 4 which is much better than the
previous 6 on 64bit and 7 on 32bit.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: remove length restriction from idr_layer->bitmap

Currently, idr->bitmap is declared as an unsigned long which restricts
the number of bits an idr_layer can contain.  All bitops can handle
arbitrary positive integer bit number and there's no reason for this
restriction.

Declare idr_layer->bitmap using DECLARE_BITMAP() instead of a single
unsigned long.

* idr_layer->bitmap is now an array.  '&' dropped from params to
  bitops.

* Replaced "== IDR_FULL" tests with bitmap_full() and removed
  IDR_FULL.

* Replaced find_next_bit() on ~bitmap with find_next_zero_bit().

* Replaced "bitmap = 0" with bitmap_clear().

This patch doesn't (or at least shouldn't) introduce any behavior
changes.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: remove MAX_IDR_MASK and move left MAX_IDR_* into idr.c

MAX_IDR_MASK is another weirdness in the idr interface.  As idr covers
whole positive integer range, it's defined as 0x7fffffff or INT_MAX.

Its usage in idr_find(), idr_replace() and idr_remove() is bizarre.
They basically mask off the sign bit and operate on the rest, so if
the caller, by accident, passes in a negative number, the sign bit
will be masked off and the remaining part will be used as if that was
the input, which is worse than crashing.

The constant is visible in idr.h and there are several users in the
kernel.

* drivers/i2c/i2c-core.c:i2c_add_numbered_adapter()

  Basically used to test if adap->nr is a negative number which isn't
  -1 and returns -EINVAL if so.  idr_alloc() already has negative
  @start checking (w/ WARN_ON_ONCE), so this can go away.

* drivers/infiniband/core/cm.c:cm_alloc_id()
  drivers/infiniband/hw/mlx4/cm.c:id_map_alloc()

  Used to wrap cyclic @start.  Can be replaced with max(next, 0).
  Note that this type of cyclic allocation using idr is buggy.  These
  are prone to spurious -ENOSPC failure after the first wraparound.

* fs/super.c:get_anon_bdev()

  The ID allocated from ida is masked off before being tested whether
  it's inside valid range.  ida allocated ID can never be a negative
  number and the masking is unnecessary.

Update idr_*() functions to fail with -EINVAL when negative @id is
specified and update other MAX_IDR_MASK users as described above.

This leaves MAX_IDR_MASK without any user, remove it and relocate
other MAX_IDR_* constants to lib/idr.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: "Marciniszyn, Mike" <mike.marciniszyn@intel.com>
Cc: Jack Morgenstein <jackm@dev.mellanox.co.il>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Wolfram Sang <wolfram@the-dreams.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: fix top layer handling

Most functions in idr fail to deal with the high bits when the idr
tree grows to the maximum height.

* idr_get_empty_slot() stops growing idr tree once the depth reaches
  MAX_IDR_LEVEL - 1, which is one depth shallower than necessary to
  cover the whole range.  The function doesn't even notice that it
  didn't grow the tree enough and ends up allocating the wrong ID
  given sufficiently high @starting_id.

  For example, on 64 bit, if the starting id is 0x7fffff01,
  idr_get_empty_slot() will grow the tree 5 layer deep, which only
  covers the 30 bits and then proceed to allocate as if the bit 30
  wasn't specified.  It ends up allocating 0x3fffff01 without the bit
  30 but still returns 0x7fffff01.

* __idr_remove_all() will not remove anything if the tree is fully
  grown.

* idr_find() can't find anything if the tree is fully grown.

* idr_for_each() and idr_get_next() can't iterate anything if the tree
  is fully grown.

Fix it by introducing idr_max() which returns the maximum possible ID
given the depth of tree and replacing the id limit checks in all
affected places.

As the idr_layer pointer array pa[] needs to be 1 larger than the
maximum depth, enlarge pa[] arrays by one.

While this plugs the discovered issues, the whole code base is
horrible and in desparate need of rewrite.  It's fragile like hell,

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nfs4client: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sctp: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Cc: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mac80211: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/9p: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

posix-timers: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

events: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc: convert to idr_alloc()

Convert to the much saner new idr interface.

The new interface doesn't directly translate to the way idr_pre_get()
was used around ipc_addid() as preloading disables preemption.  From
my cursory reading, it seems like we should be able to do all
allocation from ipc_addid(), so I moved it there.  Can you please
check whether this would be okay?  If this is wrong and ipc_addid()
should be allowed to be called from non-sleepable context, I'd suggest
allocating id itself in the outer functions and later install the
pointer using idr_replace().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ocfs2: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

inotify: convert to idr_alloc()

Convert to the much saner new idr interface.

Note that the adhoc cyclic id allocation is buggy.  If wraparound
happens, the previous code with idr_get_new_above() may segfault and
the converted code will trigger WARN and return -EINVAL.  Even if it's
fixed to wrap to zero, the code will be prone to unnecessary -ENOSPC
failures after the first wraparound.  We probably need to implement
proper cyclic support in idr.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: John McCutchan <john@johnmccutchan.com>
Cc: Robert Love <rlove@rlove.org>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dlm: convert to idr_alloc()

Convert to the much saner new idr interface.  Error return values from
recover_idr_add() mix -1 and -errno.  The conversion doesn't change
that but it looks iffy.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vfio: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

uio: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Hans J. Koch" <hjk@hansjkoch.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

thermal: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scsi/lpfc: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: James Smart <james.smart@emulex.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

target/iscsi: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scsi: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scsi/bfa: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Krishna C Gudipati <kgudipat@brocade.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rpmsg: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

remoteproc: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pps: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

power: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Anton Vorontsov <cbou@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ppp: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

macvtap: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mtd: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mmc: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Ball <cjb@laptop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

misc/tifm_core: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

misc/c2port: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mfd: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memstick: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dm: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/qib: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mike Marciniszyn <infinipath@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/ocrdma: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/mlx4: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jack Morgenstein <jackm@dev.mellanox.co.il>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/ipath: convert to idr_alloc()

Convert to the much saner new idr interface.

[yongjun_wei@trendmicro.com.cn: use GFP_NOWAIT under spin lock]
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/ehca: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Cc: Christoph Raisch <raisch@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/cxgb4: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/cxgb3: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/amso1100: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Cc: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/core: convert to idr_alloc()

Convert to the much saner new idr interface.

v2: Mike triggered WARN_ON() in idr_preload() because send_mad(),
    which may be used from non-process context, was calling
    idr_preload() unconditionally.  Preload iff @gfp_mask has
    __GFP_WAIT.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reported-by: "Marciniszyn, Mike" <mike.marciniszyn@intel.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

i2c: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Wolfram Sang <wolfram@the-dreams.de>
Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/vmwgfx: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/via: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/sis: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/i915: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/exynos: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Airlie <airlied@linux.ie>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm: convert to idr_alloc()

Convert to the much saner new idr interface.

* drm_ctxbitmap_next() error handling in drm_addctx() seems broken.
  drm_ctxbitmap_next() return -errno on failure not -1.

[artem.savkov@gmail.com: missing idr_preload_end in drm_gem_flink_ioctl]
[jslaby@suse.cz: fix drm_gem_flink_ioctl() return value]
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Artem Savkov <artem.savkov@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

firewire: convert to idr_alloc()

Convert to the much saner new idr interface.

v2: Stefan pointed out that add_client_resource() may be called from
    non-process context.  Preload iff @gfp_mask contains __GFP_WAIT.
    Also updated to include minor upper limit check.

[tim.gardner@canonical.com: fix accidentally orphaned 'minor'[
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

firewire: add minor number range check to fw_device_init()

fw_device_init() didn't check whether the allocated minor number isn't
too large.  Fail if it goes overflows MINORBITS.

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dmaengine: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Dan Williams <djbw@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dca: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drbd: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

atm/nicstar: convert to idr_alloc()

Convert to the much saner new idr interface.  The existing code looks
buggy to me - ID 0 is treated as no-ID but allocation specifies 0 as
lower limit and there's no error handling after partial success.  This
conversion keeps the bugs unchanged.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Chas Williams <chas@cmf.nrl.navy.mil>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block/loop: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block: convert to idr_alloc()

Convert to the much saner new idr interface.  Both bsg and genhd
protect idr w/ mutex making preloading unnecessary.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block: fix synchronization and limit check in blk_alloc_devt()

idr allocation in blk_alloc_devt() wasn't synchronized against lookup
and removal, and its limit check was off by one - 1 << MINORBITS is
the number of minors allowed, not the maximum allowed minor.

Add locking and rename MAX_EXT_DEVT to NR_EXT_DEVT and fix limit
checking.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: implement idr_preload[_end]() and idr_alloc()

The current idr interface is very cumbersome.

* For all allocations, two function calls - idr_pre_get() and
  idr_get_new*() - should be made.

* idr_pre_get() doesn't guarantee that the following idr_get_new*()
  will not fail from memory shortage.  If idr_get_new*() returns
  -EAGAIN, the caller is expected to retry pre_get and allocation.

* idr_get_new*() can't enforce upper limit.  Upper limit can only be
  enforced by allocating and then freeing if above limit.

* idr_layer buffer is unnecessarily per-idr.  Each idr ends up keeping
  around MAX_IDR_FREE idr_layers.  The memory consumed per idr is
  under two pages but it makes it difficult to make idr_layer larger.

This patch implements the following new set of allocation functions.

* idr_preload[_end]() - Similar to radix preload but doesn't fail.
  The first idr_alloc() inside preload section can be treated as if it
  were called with @gfp_mask used for idr_preload().

* idr_alloc() - Allocate an ID w/ lower and upper limits.  Takes
  @gfp_flags and can be used w/o preloading.  When used inside
  preloaded section, the allocation mask of preloading can be assumed.

If idr_alloc() can be called from a context which allows sufficiently
relaxed @gfp_mask, it can be used by itself.  If, for example,
idr_alloc() is called inside spinlock protected region, preloading can
be used like the following.

idr_preload(GFP_KERNEL);
spin_lock(lock);

id = idr_alloc(idr, ptr, start, end, GFP_NOWAIT);

spin_unlock(lock);
idr_preload_end();
if (id < 0)
error;

which is much simpler and less error-prone than idr_pre_get and
idr_get_new*() loop.

The new interface uses per-pcu idr_layer buffer and thus the number of
idr's in the system doesn't affect the amount of memory used for
preloading.

idr_layer_alloc() is introduced to handle idr_layer allocations for
both old and new ID allocation paths.  This is a bit hairy now but the
new interface is expected to replace the old and the internal
implementation eventually will become simpler.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: refactor idr_get_new_above()

Move slot filling to idr_fill_slot() from idr_get_new_above_int() and
make idr_get_new_above() directly call it.  idr_get_new_above_int() is
no longer needed and removed.

This will be used to implement a new ID allocation interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: remove _idr_rc_to_errno() hack

idr uses -1, IDR_NEED_TO_GROW and IDR_NOMORE_SPACE to communicate
exception conditions internally.  The return value is later translated
to errno values using _idr_rc_to_errno().

This is confusing.  Drop the custom ones and consistently use -EAGAIN
for "tree needs to grow", -ENOMEM for "need more memory" and -ENOSPC for
"ran out of ID space".

Due to the weird memory preloading mechanism, [ra]_get_new*() return
-EAGAIN on memory shortage, so we need to substitute -ENOMEM w/
-EAGAIN on those interface functions.  They'll eventually be cleaned
up and the translations will go away.

This patch doesn't introduce any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: relocate idr_for_each_entry() and reorganize id[r|a]_get_new()

* Move idr_for_each_entry() definition next to other idr related
  definitions.

* Make id[r|a]_get_new() inline wrappers of id[r|a]_get_new_above().

This changes the implementation of idr_get_new() but the new
implementation is trivial.  This patch doesn't introduce any
functional change.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: cosmetic updates to struct / initializer definitions

* Tab align fields like a normal person.

* Drop the unnecessary 0 inits from IDR_INIT().

This patch is purely cosmetic.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: deprecate idr_remove_all()

There was only one legitimate use of idr_remove_all() and a lot more of
incorrect uses (or lack of it).  Now that idr_destroy() implies
idr_remove_all() and all the in-kernel users updated not to use it,
there's no reason to keep it around.  Mark it deprecated so that we can
later unexport it.

idr_remove_all() is made an inline function calling __idr_remove_all()
to avoid triggering deprecated warning on EXPORT_SYMBOL().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

inotify: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: John McCutchan <john@johnmccutchan.com>
Cc: Robert Love <rlove@rlove.org>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nfs: idr_destroy() no longer needs idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop reference to idr_remove_all().  Note that the code
wasn't completely correct before because idr_remove() on all entries
doesn't necessarily release all idr_layers which could lead to memory
leak.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dlm: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.

The conversion isn't completely trivial for recover_idr_clear() as it's
the only place in kernel which makes legitimate use of idr_remove_all()
w/o idr_destroy().  Replace it with idr_remove() call inside
idr_for_each_entry() loop.  It goes on top so that it matches the
operation order in recover_idr_del().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christine Caulfield <ccaulfie@redhat.com>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dlm: use idr_for_each_entry() in recover_idr_clear() error path

Convert recover_idr_clear() to use idr_for_each_entry() instead of
idr_for_each().  It's somewhat less efficient this way but it shouldn't
matter in an error path.  This is to help with deprecation of
idr_remove_all().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christine Caulfield <ccaulfie@redhat.com>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rpmsg: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

remoteproc: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dm: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

* drm_ctxbitmap_cleanup() was calling idr_remove_all() but forgetting
  idr_destroy() thus leaking all buffered free idr_layers.  Replace it
  with idr_destroy().

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Airlie <airlied@linux.ie>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

firewire: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block/loop: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

atm/nicstar: don't use idr_remove_all()

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chas Williams <chas@cmf.nrl.navy.mil>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: make idr_destroy() imply idr_remove_all()

idr is silly in quite a few ways, one of which is how it's supposed to
be destroyed - idr_destroy() doesn't release IDs and doesn't even whine
if the idr isn't empty.  If the caller forgets idr_remove_all(), it
simply leaks memory.

Even ida gets this wrong and leaks memory on destruction.  There is
absoltely no reason not to call idr_remove_all() from idr_destroy().
Nobody is abusing idr_destroy() for shrinking free layer buffer and
continues to use idr after idr_destroy(), so it's safe to do remove_all
from destroy.

In the whole kernel, there is only one place where idr_remove_all() is
legitimiately used without following idr_destroy() while there are quite
a few places where the caller forgets either idr_remove_all() or
idr_destroy() leaking memory.

This patch makes idr_destroy() call idr_destroy_all() and updates the
function description accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

idr: fix a subtle bug in idr_get_next()

The iteration logic of idr_get_next() is borrowed mostly verbatim from
idr_for_each().  It walks down the tree looking for the slot matching
the current ID.  If the matching slot is not found, the ID is
incremented by the distance of single slot at the given level and
repeats.

The implementation assumes that during the whole iteration id is aligned
to the layer boundaries of the level closest to the leaf, which is true
for all iterations starting from zero or an existing element and thus is
fine for idr_for_each().

However, idr_get_next() may be given any point and if the starting id
hits in the middle of a non-existent layer, increment to the next layer
will end up skipping the same offset into it.  For example, an IDR with
IDs filled between [64, 127] would look like the following.

          [  0  64 ... ]
       /----/   |
       |        |
      NULL    [ 64 ... 127 ]

If idr_get_next() is called with 63 as the starting point, it will try
to follow down the pointer from 0.  As it is NULL, it will then try to
proceed to the next slot in the same level by adding the slot distance
at that level which is 64 - making the next try 127.  It goes around the
loop and finds and returns 127 skipping [64, 126].

Note that this bug also triggers in idr_for_each_entry() loop which
deletes during iteration as deletions can make layers go away leaving
the iteration with unaligned ID into missing layers.

Fix it by ensuring proceeding to the next slot doesn't carry over the
unaligned offset - ie.  use round_up(id + 1, slot_distance) instead of
id += slot_distance.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: David Teigland <teigland@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block: fix ext_devt_idr handling

While adding and removing a lot of disks disks and partitions this
sometimes shows up:

  WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted)
  Hardware name:
  sysfs: cannot create duplicate filename '/dev/block/259:751'
  Modules linked in: raid1 autofs4 bnx2fc cnic uio fcoe libfcoe libfc 8021q scsi_transport_fc scsi_tgt garp stp llc sunrpc cpufreq_ondemand powernow_k8 freq_table mperf ipv6 dm_mirror dm_region_hash dm_log power_meter microcode dcdbas serio_raw amd64_edac_mod edac_core edac_mce_amd i2c_piix4 i2c_core k10temp bnx2 sg ixgbe dca mdio ext4 mbcache jbd2 dm_round_robin sr_mod cdrom sd_mod crc_t10dif ata_generic pata_acpi pata_atiixp ahci mptsas mptscsih mptbase scsi_transport_sas dm_multipath dm_mod [last unloaded: scsi_wait_scan]
  Pid: 44103, comm: async/16 Not tainted 2.6.32-195.el6.x86_64 #1
  Call Trace:
    warn_slowpath_common+0x87/0xc0
    warn_slowpath_fmt+0x46/0x50
    sysfs_add_one+0xc9/0x130
    sysfs_do_create_link+0x12b/0x170
    sysfs_create_link+0x13/0x20
    device_add+0x317/0x650
    idr_get_new+0x13/0x50
    add_partition+0x21c/0x390
    rescan_partitions+0x32b/0x470
    sd_open+0x81/0x1f0 [sd_mod]
    __blkdev_get+0x1b6/0x3c0
    blkdev_get+0x10/0x20
    register_disk+0x155/0x170
    add_disk+0xa6/0x160
    sd_probe_async+0x13b/0x210 [sd_mod]
    add_wait_queue+0x46/0x60
    async_thread+0x102/0x250
    default_wake_function+0x0/0x20
    async_thread+0x0/0x250
    kthread+0x96/0xa0
    child_rip+0xa/0x20
    kthread+0x0/0xa0
    child_rip+0x0/0x20

This most likely happens because dev_t is freed while the number is
still used and idr_get_new() is not protected on every use.  The fix
adds a mutex where it wasn't before and moves the dev_t free function so
it is called after device del.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: avoid freeing NULL pointer in image_crash_alloc()

Though there is no error if we free a NULL pointer, I think we could
avoid this behaviour.  Change the code a little in kimage_crash_alloc()
could avoid this kind of unnecessary free.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: fix memory leak in function kimage_normal_alloc

If kimage_normal_alloc() fails to alloc pages for image->swap_page, it
should call kimage_free_page_list() to free allocated pages in
image->control_pages list before it frees image.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: prevent double free on image allocation failure

If kimage_normal_alloc() fails to initialize an allocated kimage, it will
free the image but would still set 'rimage', as a result kexec_load will
try to free it again.

This would explode as part of the freeing process is accessing internal
members which point to uninitialized memory.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: export PG_hwpoison flag into vmcoreinfo

This patch exports a PG_hwpoison into vmcoreinfo when
CONFIG_MEMORY_FAILURE is defined.  "makedumpfile" needs to read
information of memory, such as 'mem_section', 'zone', 'pageflags' from
vmcore.

We introduce a function into "makedumpfile" to exclude hwpoison page from
vmcore dump.  In order to introduce this function, PG_hwpoison flag have
to export into vmcoreinfo.

Signed-off-by: Mitsuhiro Tanino <mitsuhiro.tanino.gm@hitachi.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Mitsuhiro Tanino <mitsuhiro.tanino.gm@hitachi.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: get rid of duplicate check for hole_end

hole_end has been checked to make sure it is <= crash_res.end in the while
condition check, so the if condition check is duplicate.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: add the values related to buddy system for filtering free pages.

tAdd adds the values related to buddy system to vmcoreinfo data so that
makedumpfile (dump filtering command) can filter out all free pages with
the new logic.

It's faster than the current logic because it can distinguish free page
by analyzing page structure at the same time as filtering for other
unnecessary pages (e.g.  anonymous page).

OTOH, the current logic has to trace free_list to distinguish free pages
while analyzing page structure to filter out other unnecessary pages.

The new logic uses the fact that buddy page is marked by _mapcount ==
PAGE_BUDDY_MAPCOUNT_VALUE.  But, _mapcount shares its memory with other
fields for SLAB/SLUB when PG_slab is set, so we need to check if PG_slab
is set or not before looking up _mapcount value.  And we can get the
order of buddy system from private field.  To sum it up, the values
below are required for this logic.

Required values:
  - OFFSET(page._mapcount)
  - OFFSET(page.private)
  - NUMBER(PG_slab)
  - NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE)

Changelog from v1 to v2:
1. remove SIZE(pageflags)
  The new logic was changed after I sent v1 patch.
  Accordingly, SIZE(pageflags) has been unnecessary for makedumpfile.

What's makedumpfile:
  makedumpfile creates a small dumpfile by excluding unnecessary pages
  for the analysis. To distinguish unnecessary pages, makedumpfile gets
  the vmcoreinfo data which has the minimum debugging information only
  for dump filtering.

Signed-off-by: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fork: unshare: remove dead code

If new_nsproxy is set we will always call switch_task_namespaces and
then set new_nsproxy back to NULL so the reassignment and fall through
check are redundant

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/seq_file.c:seq_lseek(): fix switch statement indenting

[akpm@linux-foundation.org: checkpatch fixes]
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq-file: use SEEK_ macros instead of hardcoded numbers

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

coredump: use a freezable_schedule for the coredump_finish wait

Prevents hung_task detector from panicing the machine. This is also
needed to prevent this wait from blocking suspend.

(It doesnt' currently block suspend but it would once the next
patch in this series is applied.)

[yongjun_wei@trendmicro.com.cn: kernel/exit.c: remove duplicated include]
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ben Chan <benchan@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lockdep: check that no locks held at freeze time

We shouldn't try_to_freeze if locks are held.  Holding a lock can cause a
deadlock if the lock is later acquired in the suspend or hibernate path
(e.g.  by dpm).  Holding a lock can also cause a deadlock in the case of
cgroup_freezer if a lock is held inside a frozen cgroup that is later
acquired by a process outside that group.

[akpm@linux-foundation.org: export debug_check_no_locks_held]
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ben Chan <benchan@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>