serial: samsung: fix leaked requested irq

The s3c64xx_serial_startup() requests an IRQ, but the common
s3c24xx_serial_shutdown() would not free it.

s3c64xx_serial_startup() is used when
s3c24xx_serial_has_interrupt_mask(port) is true, at which point
  ourport->rx_claimed = ourport->tx_claimed = 1
so we only need to free in one of the claimed cases.

Change-Id: I8e17ce52cf48dbf3faa26ac24c8a71f016771f32
Signed-off-by: JP Abgrall <jpa@google.com>
ALSA: hda - hdmi: Make jacks phantom, if they're not detectable

commit 30efd8debd1ef30be342d374f01e993509f5b76b upstream.

Just as for analog codecs, a jack that isn't suitable for detection
(in this case, NO_PRESENCE was set) should be a phantom Jack
instead of a normal one.

Thanks to Raymond Yau for spotting.

BugLink: https://bugs.launchpad.net/bugs/961286
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=903869
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
quota: autoload the quota_v2 module for QFMT_VFS_V1 quota format

commit c3ad83d9efdfe6a86efd44945a781f00c879b7b4 upstream.

Otherwise, ext4 file systems with the quota featured enable will get a
very confusing "No such process" error message if the quota code is
built as a module and the quota_v2 module has not been loaded.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
iommu/amd: Initialize device table after dma_ops

commit f528d980c17b8714aedc918ba86e058af914d66b upstream.

When dma_ops are initialized the unity mappings are
created. The init_device_table_dma() function makes sure DMA
from all devices is blocked by default. This opens a short
window in time where DMA to unity mapped regions is blocked
by the IOMMU. Make sure this does not happen by initializing
the device table after dma_ops.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
posix-timer: Don't call idr_find() with out-of-range ID

commit e182bb38d7db7494fa5dcd82da17fe0dedf60ecf upstream.

When idr_find() was fed a negative ID, it used to look up the ID
ignoring the sign bit before recent ("idr: remove MAX_IDR_MASK and
move left MAX_IDR_* into idr.c") patch. Now a negative ID triggers
a WARN_ON_ONCE().

__lock_timer() feeds timer_id from userland directly to idr_find()
without sanitizing it which can trigger the above malfunctions.  Add a
range check on @timer_id before invoking idr_find() in __lock_timer().

While timer_t is defined as int by all archs at the moment, Andrew
worries that it may be defined as a larger type later on.  Make the
test cover larger integers too so that it at least is guaranteed to
not return the wrong timer.

Note that WARN_ON_ONCE() in idr_find() on id < 0 is transitional
precaution while moving away from ignoring MSB.  Once it's gone we can
remove the guard as long as timer_t isn't larger than int.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20130220232412.GL3570@htj.dyndns.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Call ftrace cleanup module notifier after all other notifiers

commit 8c189ea64eea01ca20d102ddb74d6936dd16c579 upstream.

Commit: c1bf08ac "ftrace: Be first to run code modification on modules"

changed ftrace module notifier's priority to INT_MAX in order to
process the ftrace nops before anything else could touch them
(namely kprobes). This was the correct thing to do.

Unfortunately, the ftrace module notifier also contains the ftrace
clean up code. As opposed to the set up code, this code should be
run *after* all the module notifiers have run in case a module is doing
correct clean-up and unregisters its ftrace hooks. Basically, ftrace
needs to do clean up on module removal, as it needs to know about code
being removed so that it doesn't try to modify that code. But after it
removes the module from its records, if a ftrace user tries to remove
a probe, that removal will fail due as the record of that code segment
no longer exists.

Nothing really bad happens if the probe removal is called after ftrace
did the clean up, but the ftrace removal function will return an error.
Correct code (such as kprobes) will produce a WARN_ON() if it fails
to remove the probe. As people get annoyed by frivolous warnings, it's
best to do the ftrace clean up after everything else.

By splitting the ftrace_module_notifier into two notifiers, one that
does the module load setup that is run at high priority, and the other
that is called for module clean up that is run at low priority, the
problem is solved.

Reported-by: Frank Ch. Eigler <fche@redhat.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	kernel/trace/ftrace.c
x86, efi: Make "noefi" really disable EFI runtime serivces

commit fb834c7acc5e140cf4f9e86da93a66de8c0514da upstream.

commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than
EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to
its documentation and disable EFI runtime services to prevent the
bricking bug described in commit e0094244e41c ("samsung-laptop:
Disable on EFI hardware"). However, it's not possible to clear
EFI_RUNTIME_SERVICES from an early param function because
EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param().

This resulted in "noefi" effectively becoming a no-op and no longer
providing users with a way to disable EFI, which is bad for those
users that have buggy machines.

Reported-by: Walt Nelson Jr <walt0924@gmail.com>
Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
doc, xen: Mention 'earlyprintk=xen' in the documentation.

commit 2482a92e7d17187301d7313cfe5021b13393a0b4 upstream.

The earlyprintk for Xen PV guests utilizes a simple hypercall
(console_io) to provide output to Xen emergency console.

Note that the Xen hypervisor should be booted with 'loglevel=all'
to output said information.

Reported-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1361825650-14031-2-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
doc, kernel-parameters: Document 'console=hvc<n>'

commit a2fd6419174470f5ae6383f5037d0ee21ed9833f upstream.

Both the PowerPC hypervisor and Xen hypervisor can utilize the
hvc driver.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1361825650-14031-3-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86: Make sure we can boot in the case the BDA contains pure garbage

commit 7c10093692ed2e6f318387d96b829320aa0ca64c upstream.

On non-BIOS platforms it is possible that the BIOS data area contains
garbage instead of being zeroed or something equivalent (firmware
people: we are talking of 1.5K here, so please do the sane thing.)

We need on the order of 20-30K of low memory in order to boot, which
may grow up to < 64K in the future.  We probably want to avoid the
lowest of the low memory.  At the same time, it seems extremely
unlikely that a legitimate EBDA would ever reach down to the 128K
(which would require it to be over half a megabyte in size.)  Thus,
pick 128K as the cutoff for "this is insane, ignore."  We may still
end up reserving a bunch of extra memory on the low megabyte, but that
is not really a major issue these days.  In the worst case we lose
512K of RAM.

This code really should be merged with trim_bios_range() in
arch/x86/kernel/setup.c, but that is a bigger patch for a later merge
window.

Reported-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/n/tip-oebml055yyfm8yxmria09rja@git.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
target: Fix lookup of dynamic NodeACLs during cached demo-mode operation

commit fcf29481fb8e106daad6688f2e898226ee928992 upstream.

This patch fixes a bug in core_tpg_check_initiator_node_acl() ->
core_tpg_get_initiator_node_acl() where a dynamically created
se_node_acl generated during session login would be skipped during
subsequent lookup due to the '!acl->dynamic_node_acl' check, causing
a new se_node_acl to be created with a duplicate ->initiatorname.

This would occur when a fabric endpoint was configured with
TFO->tpg_check_demo_mode()=1 + TPF->tpg_check_demo_mode_cache()=1
preventing the release of an existing se_node_acl during se_session
shutdown.

Also, drop the unnecessary usage of core_tpg_get_initiator_node_acl()
within core_dev_init_initiator_node_lun_acl() that originally
required the extra '!acl->dynamic_node_acl' check, and just pass
the configfs provided se_node_acl pointer instead.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
target: Add missing mapped_lun bounds checking during make_mappedlun setup

commit fbbf8555a986ed31e54f006b6cc637ea4ff1425b upstream.

This patch adds missing bounds checking for the configfs provided
mapped_lun value during target_fabric_make_mappedlun() setup ahead
of se_lun_acl initialization.

This addresses a potential OOPs when using a mapped_lun value that
exceeds the hardcoded TRANSPORT_MAX_LUNS_PER_TPG-1 value within
se_node_acl->device_list[].

Reported-by: Jan Engelhardt <jengelh@inai.de>
Cc: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ocfs2: fix possible use-after-free with AIO

commit 9b171e0c74ca0549d0610990a862dd895870f04a upstream.

Running AIO is pinning inode in memory using file reference. Once AIO
is completed using aio_complete(), file reference is put and inode can
be freed from memory. So we have to be sure that calling aio_complete()
is the last thing we do with the inode.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ocfs2: fix ocfs2_init_security_and_acl() to initialize acl correctly

commit 32918dd9f19e5960af4cdfa41190bb843fb2247b upstream.

We need to re-initialize the security for a new reflinked inode with its
parent dirs if it isn't specified to be preserved for ocfs2_reflink().
However, the code logic is broken at ocfs2_init_security_and_acl()
although ocfs2_init_security_get() succeed.  As a result,
ocfs2_acl_init() does not involked and therefore the default ACL of
parent dir was missing on the new inode.

Note this was introduced by 9d8f13ba3 ("security: new
security_inode_init_security API adds function callback")

To reproduce:

    set default ACL for the parent dir(ocfs2 in this case):
    $ setfacl -m default:user:jeff:rwx ../ocfs2/
    $ getfacl ../ocfs2/
    # file: ../ocfs2/
    # owner: jeff
    # group: jeff
    user::rwx
    group::r-x
    other::r-x
    default:user::rwx
    default:user:jeff:rwx
    default:group::r-x
    default:mask::rwx
    default:other::r-x

    $ touch a
    $ getfacl a
    # file: a
    # owner: jeff
    # group: jeff
    user::rw-
    group::rw-
    other::r--

Before patching, create reflink file b from a, the user
default ACL entry(user:jeff:rwx)was missing:

    $ ./ocfs2_reflink a b
    $ getfacl b
    # file: b
    # owner: jeff
    # group: jeff
    user::rw-
    group::rw-
    other::r--

In this case, the end user can also observed an error message at syslog:

  (ocfs2_reflink,3229,2):ocfs2_init_security_and_acl:7193 ERROR: status = 0

After applying this patch, create reflink file c from a:

    $ ./ocfs2_reflink a c
    $ getfacl c
    # file: c
    # owner: jeff
    # group: jeff
    user::rw-
    user:jeff:rwx			#effective:rw-
    group::r-x			#effective:r--
    mask::rw-
    other::r--

Test program:
/* Usage: reflink <source> <dest> */
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>

static int
reflink_file(char const *src_name, char const *dst_name,
	     bool preserve_attrs)
{
	int fd;

#ifndef REFLINK_ATTR_NONE
#  define REFLINK_ATTR_NONE 0
#endif
#ifndef REFLINK_ATTR_PRESERVE
#  define REFLINK_ATTR_PRESERVE 1
#endif
#ifndef OCFS2_IOC_REFLINK
	struct reflink_arguments {
		uint64_t old_path;
		uint64_t new_path;
		uint64_t preserve;
	};

#  define OCFS2_IOC_REFLINK _IOW ('o', 4, struct reflink_arguments)
#endif
	struct reflink_arguments args = {
		.old_path = (unsigned long) src_name,
		.new_path = (unsigned long) dst_name,
		.preserve = preserve_attrs ? REFLINK_ATTR_PRESERVE :
					     REFLINK_ATTR_NONE,
	};

	fd = open(src_name, O_RDONLY);
	if (fd < 0) {
		fprintf(stderr, "Failed to open %s: %s\n",
			src_name, strerror(errno));
		return -1;
	}

	if (ioctl(fd, OCFS2_IOC_REFLINK, &args) < 0) {
		fprintf(stderr, "Failed to reflink %s to %s: %s\n",
			src_name, dst_name, strerror(errno));
		return -1;
	}
}

int
main(int argc, char *argv[])
{
	if (argc != 3) {
		fprintf(stdout, "Usage: %s source dest\n", argv[0]);
		return 1;
	}

	return reflink_file(argv[1], argv[2], 0);
}

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Tao Ma <boyu.mt@taobao.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ocfs2: ac->ac_allow_chain_relink=0 won't disable group relink

commit 309a85b6861fedbb48a22d45e0e079d1be993b3a upstream.

ocfs2_block_group_alloc_discontig() disables chain relink by setting
ac->ac_allow_chain_relink = 0 because it grabs clusters from multiple
cluster groups.

It doesn't keep the credits for all chain relink,but
ocfs2_claim_suballoc_bits overrides this in this call trace:
ocfs2_block_group_claim_bits()->ocfs2_claim_clusters()->
__ocfs2_claim_clusters()->ocfs2_claim_suballoc_bits()
ocfs2_claim_suballoc_bits set ac->ac_allow_chain_relink = 1; then call
ocfs2_search_chain() one time and disable it again, and then we run out
of credits.

Fix is to allow relink by default and disable it in
ocfs2_block_group_alloc_discontig.

Without this patch, End-users will run into a crash due to run out of
credits, backtrace like this:

  RIP: 0010:[<ffffffffa0808b14>]  [<ffffffffa0808b14>]
  jbd2_journal_dirty_metadata+0x164/0x170 [jbd2]
  RSP: 0018:ffff8801b919b5b8  EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff88022139ddc0 RCX: ffff880159f652d0
  RDX: ffff880178aa3000 RSI: ffff880159f652d0 RDI: ffff880087f09bf8
  RBP: ffff8801b919b5e8 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000001e00 R11: 00000000000150b0 R12: ffff880159f652d0
  R13: ffff8801a0cae908 R14: ffff880087f09bf8 R15: ffff88018d177800
  FS:  00007fc9b0b6b6e0(0000) GS:ffff88022fd40000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 000000000040819c CR3: 0000000184017000 CR4: 00000000000006e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process dd (pid: 9945, threadinfo ffff8801b919a000, task ffff880149a264c0)
  Call Trace:
    ocfs2_journal_dirty+0x2f/0x70 [ocfs2]
    ocfs2_relink_block_group+0x111/0x480 [ocfs2]
    ocfs2_search_chain+0x455/0x9a0 [ocfs2]
    ...

Signed-off-by: Xiaowei.Hu <xiaowei.hu@oracle.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
block: fix ext_devt_idr handling

commit 7b74e912785a11572da43292786ed07ada7e3e0c upstream.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xen-blkback: do not leak mode property

commit 9d092603cc306ee6edfe917bf9ab8beb5f32d7bc upstream.

"be->mode" is obtained from xenbus_read(), which does a kmalloc() for
the message body. The short string is never released, so do it along
with freeing "be" itself, and make sure the string isn't kept when
backend_changed() doesn't complete successfully (which made it
desirable to slightly re-structure that function, so that the error
cleanup can be done in one place).

Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xen/blkback: Don't trust the handle from the frontend.

commit 01c681d4c70d64cb72142a2823f27c4146a02e63 upstream.

The 'handle' is the device that the request is from. For the life-time
of the ring we copy it from a request to a response so that the frontend
is not surprised by it. But we do not need it - when we start processing
I/Os we have our own 'struct phys_req' which has only most essential
information about the request. In fact the 'vbd_translate' ends up
over-writing the preq.dev with a value from the backend.

This assignment of preq.dev with the 'handle' value is superfluous
so lets not do it.

Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
idr: fix a subtle bug in idr_get_next()

commit 6cdae7416a1c45c2ce105a78187d9b7e8feb9e24 upstream.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
block: fix synchronization and limit check in blk_alloc_devt()

commit ce23bba842aee98092225d9576dba47c82352521 upstream.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>