The iSCSI session recovery_tmo setting is writeable in sysfs, but it's
also set every time a connection is established when parameters are set
from iscsid over netlink.  That results in the timeout being reset to
the default value after every recovery.

The DM multipath tools want to use the sysfs interface to lower the
default timeout when there are multiple paths to fail over.  It has
caused confusion that we have a writeable sysfs value that seem to keep
resetting itself.

This patch adds an in-kernel flag that gets set once a sysfs write
occurs, and then ignores netlink parameter setting once it's been
modified via the sysfs interface.  My thinking here is that the sysfs
interface is much simpler for external tools to influence the session
timeout, but if we're going to allow it to be modified directly we
should ensure that setting is maintained.
Signed-off-by: Chris Leech <cleech@redhat.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Some misc fixes for endianness checking with sparse so sparse with
endian checking now runs clean. Fixes a minor bug in the process
which was uncovered by sparse which would result in unnecessary
error recovery for check conditions.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

On LE system, users see the wrong device_id attribute. This patch
does necessary byte swapping for device_id attribute and works on
both of LE and BE systems.
Signed-off-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

The 'sd' driver is calling scsi_mode_sense() to figure out
internal details. But scsi_mode_sense() never checks for
any pending unit attentions, so we're getting annoying error
messages like:

MODE SENSE: unimplemented page/subpage: 0x00/0x00

and a possible wrong decision for device cache handling.
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Fix a memory leak with scsi-mq triggered by commands with large data
transfer length.

__sg_alloc_table() sets both table->nents and table->orig_nents to the
same value.  When the scatterlist is DMA-mapped, table->nents is
overwritten with the (possibly smaller) size of the DMA-mapped
scatterlist, while table->orig_nents retains the original size of the
allocated scatterlist.  scsi_free_sgtable() should therefore check
orig_nents instead of nents, and all code that initializes sdb->table
without calling __sg_alloc_table() should set both nents and orig_nents.

Fixes: d285203c ("scsi: add support for a blk-mq based I/O path.")
Cc: <stable@vger.kernel.org> # 3.17+
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Fixes another signed / unsigned array indexing bug in the ipr driver.
Currently, when hrrq_index wraps, it becomes a negative number. We
do the modulo, but still have a negative number, so we end up indexing
backwards in the array. Given where the hrrq array is located in memory,
we probably won't actually reference memory we don't own, but nonetheless
ipr is still looking at data within struct ipr_ioa_cfg and interpreting it as
struct ipr_hrr_queue data, so bad things could certainly happen.

Each ipr adapter has anywhere from 1 to 16 HRRQs. By default, we use 2 on new
adapters.  Let's take an example:

Assume ioa_cfg->hrrq_index=0x7fffffffe and ioa_cfg->hrrq_num=4:

The atomic_add_return will then return -1. We mod this with 3 and get -2, add
one and get -1 for an array index.

On adapters which support more than a single HRRQ, we dedicate HRRQ to adapter
initialization and error interrupts so that we can optimize the other queues
for fast path I/O. So all normal I/O uses HRRQ 1-15. So we want to spread the
I/O requests across those HRRQs.

With the default module parameter settings, this bug won't hit, only when
someone sets the ipr.number_of_msix parameter to a value larger than 3 is when
bad things start to happen.

Cc: <stable@vger.kernel.org>
Tested-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

When ipr's internal driver trace was changed to an atomic, a signed/unsigned
bug slipped in which results in us indexing backwards in our memory buffer
writing on memory that does not belong to us. This patch fixes this by removing
the modulo and instead just mask off the low bits.

Cc: <stable@vger.kernel.org>
Tested-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Make sure we have the host lock held when calling scsi_report_bus_reset. Fixes
a crash seen as the __devices list in the scsi host was changing as we were
iterating through it.

Cc: <stable@vger.kernel.org>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Commit 1e6f2416 changed the scsi sysfs 'queue_depth' code to
rejects depths higher than the scsi host template setting. But lots
of hosts set this to 1, and update the settings in the scsi host
when the controller/devices probing happens.

This breaks (at least) mpt2sas and mpt3sas runtime setting of queue
depth, returning EINVAL for all settings but '1'. And once it's set to
1, there's no way to go back up.

Cc: stable@vger.kernel.org
Fixes: 1e6f2416 "scsi: don't allow setting of queue_depth bigger than can_queue"
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Two SLES11 SP3 servers encountered similar crashes simultaneously
following some kind of SAN/tape target issue:

...
qla2xxx [0000:81:00.0]-801c:3: Abort command issued nexus=3:0:2 --  1 2002.
qla2xxx [0000:81:00.0]-801c:3: Abort command issued nexus=3:0:2 --  1 2002.
qla2xxx [0000:81:00.0]-8009:3: DEVICE RESET ISSUED nexus=3:0:2 cmd=ffff882f89c2c7c0.
qla2xxx [0000:81:00.0]-800c:3: do_reset failed for cmd=ffff882f89c2c7c0.
qla2xxx [0000:81:00.0]-800f:3: DEVICE RESET FAILED: Task management failed nexus=3:0:2 cmd=ffff882f89c2c7c0.
qla2xxx [0000:81:00.0]-8009:3: TARGET RESET ISSUED nexus=3:0:2 cmd=ffff882f89c2c7c0.
qla2xxx [0000:81:00.0]-800c:3: do_reset failed for cmd=ffff882f89c2c7c0.
qla2xxx [0000:81:00.0]-800f:3: TARGET RESET FAILED: Task management failed nexus=3:0:2 cmd=ffff882f89c2c7c0.
qla2xxx [0000:81:00.0]-8012:3: BUS RESET ISSUED nexus=3:0:2.
qla2xxx [0000:81:00.0]-802b:3: BUS RESET SUCCEEDED nexus=3:0:2.
qla2xxx [0000:81:00.0]-505f:3: Link is operational (8 Gbps).
qla2xxx [0000:81:00.0]-8018:3: ADAPTER RESET ISSUED nexus=3:0:2.
qla2xxx [0000:81:00.0]-00af:3: Performing ISP error recovery - ha=ffff88bf04d18000.
 rport-3:0-0: blocked FC remote port time out: removing target and saving binding
qla2xxx [0000:81:00.0]-505f:3: Link is operational (8 Gbps).
qla2xxx [0000:81:00.0]-8017:3: ADAPTER RESET SUCCEEDED nexus=3:0:2.
 rport-2:0-0: blocked FC remote port time out: removing target and saving binding
sg_rq_end_io: device detached
BUG: unable to handle kernel NULL pointer dereference at 00000000000002a8
IP: [<ffffffff8133b268>] __pm_runtime_idle+0x28/0x90
PGD 7e6586f067 PUD 7e5af06067 PMD 0 [1739975.390354] Oops: 0002 [#1] SMP
CPU 0
...
Supported: No, Proprietary modules are loaded [1739975.390463]
Pid: 27965, comm: ABCD Tainted: PF           X 3.0.101-0.29-default #1 HP ProLiant DL580 Gen8
RIP: 0010:[<ffffffff8133b268>]  [<ffffffff8133b268>] __pm_runtime_idle+0x28/0x90
RSP: 0018:ffff8839dc1e7c68  EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff883f0592fc00 RCX: 0000000000000090
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000138
RBP: 0000000000000138 R08: 0000000000000010 R09: ffffffff81bd39d0
R10: 00000000000009c0 R11: ffffffff81025790 R12: 0000000000000001
R13: ffff883022212b80 R14: 0000000000000004 R15: ffff883022212b80
FS:  00007f8e54560720(0000) GS:ffff88407f800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000000000002a8 CR3: 0000007e6ced6000 CR4: 00000000001407f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process ABCD (pid: 27965, threadinfo ffff8839dc1e6000, task ffff883592e0c640)
Stack:
 ffff883f0592fc00 00000000fffffffa 0000000000000001 ffff883022212b80
 ffff883eff772400 ffffffffa03fa309 0000000000000000 0000000000000000
 ffffffffa04003a0 ffff883f063196c0 ffff887f0379a930 ffffffff8115ea1e
Call Trace:
 [<ffffffffa03fa309>] st_open+0x129/0x240 [st]
 [<ffffffff8115ea1e>] chrdev_open+0x13e/0x200
 [<ffffffff811588a8>] __dentry_open+0x198/0x310
 [<ffffffff81167d74>] do_last+0x1f4/0x800
 [<ffffffff81168fe9>] path_openat+0xd9/0x420
 [<ffffffff8116946c>] do_filp_open+0x4c/0xc0
 [<ffffffff8115a00f>] do_sys_open+0x17f/0x250
 [<ffffffff81468d92>] system_call_fastpath+0x16/0x1b
 [<00007f8e4f617fd0>] 0x7f8e4f617fcf
Code: eb d3 90 48 83 ec 28 40 f6 c6 04 48 89 6c 24 08 4c 89 74 24 20 48 89 fd 48 89 1c 24 4c 89 64 24 10 41 89 f6 4c 89 6c 24 18 74 11 <f0> ff 8f 70 01 00 00 0f 94 c0 45 31 ed 84 c0 74 2b 4c 8d a5 a0
RIP  [<ffffffff8133b268>] __pm_runtime_idle+0x28/0x90
 RSP <ffff8839dc1e7c68>
CR2: 00000000000002a8

Analysis reveals the cause of the crash to be due to STp->device
being NULL. The pointer was NULLed via scsi_tape_put(STp) when it
calls scsi_tape_release(). In st_open() we jump to err_out after
scsi_block_when_processing_errors() completes and returns the
device as offline (sdev_state was SDEV_DEL):

1180 /* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1181    module count. */
1182 static int st_open(struct inode *inode, struct file *filp)
1183 {
1184         int i, retval = (-EIO);
1185         int resumed = 0;
1186         struct scsi_tape *STp;
1187         struct st_partstat *STps;
1188         int dev = TAPE_NR(inode);
1189         char *name;
...
1217         if (scsi_autopm_get_device(STp->device) < 0) {
1218                 retval = -EIO;
1219                 goto err_out;
1220         }
1221         resumed = 1;
1222         if (!scsi_block_when_processing_errors(STp->device)) {
1223                 retval = (-ENXIO);
1224                 goto err_out;
1225         }
...
1264  err_out:
1265         normalize_buffer(STp->buffer);
1266         spin_lock(&st_use_lock);
1267         STp->in_use = 0;
1268         spin_unlock(&st_use_lock);
1269         scsi_tape_put(STp); <-- STp->device = 0 after this
1270         if (resumed)
1271                 scsi_autopm_put_device(STp->device);
1272         return retval;

The ref count for the struct scsi_tape had already been reduced
to 1 when the .remove method of the st module had been called.
The kref_put() in scsi_tape_put() caused scsi_tape_release()
to be called:

0266 static void scsi_tape_put(struct scsi_tape *STp)
0267 {
0268         struct scsi_device *sdev = STp->device;
0269
0270         mutex_lock(&st_ref_mutex);
0271         kref_put(&STp->kref, scsi_tape_release); <-- calls this
0272         scsi_device_put(sdev);
0273         mutex_unlock(&st_ref_mutex);
0274 }

In scsi_tape_release() the struct scsi_device in the struct
scsi_tape gets set to NULL:

4273 static void scsi_tape_release(struct kref *kref)
4274 {
4275         struct scsi_tape *tpnt = to_scsi_tape(kref);
4276         struct gendisk *disk = tpnt->disk;
4277
4278         tpnt->device = NULL; <<<---- where the dev is nulled
4279
4280         if (tpnt->buffer) {
4281                 normalize_buffer(tpnt->buffer);
4282                 kfree(tpnt->buffer->reserved_pages);
4283                 kfree(tpnt->buffer);
4284         }
4285
4286         disk->private_data = NULL;
4287         put_disk(disk);
4288         kfree(tpnt);
4289         return;
4290 }

Although the problem was reported on SLES11.3 the problem appears
in linux-next as well.

The crash is fixed by reordering the code so we no longer access
the struct scsi_tape after the kref_put() is done on it in st_open().
Signed-off-by: Shane Seymour <shane.seymour@hp.com>
Signed-off-by: Darren Lavender <darren.lavender@hp.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Odin.com>

This reverts commit dec4f799.

Jörg Otte reports a NULL pointder dereference due to this commit, as
'crtc_state' very much can be NULL:

        crtc_state = state->base.state ?
                intel_atomic_get_crtc_state(state->base.state, intel_crtc) : NULL;

So the change to test 'crtc_state->base.active' cannot possibly be
correct as-is.

There may be some other minimal fix (like just checking crtc_state for
NULL), but I'm just reverting it now for the rc2 release, and people
like Daniel Vetter who actually know this code will figure out what the
right solution is in the longer term.
Reported-and-bisected-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
CC: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull VFS fixes from Al Viro:
 "Fixes for this cycle regression in overlayfs and a couple of
  long-standing (== all the way back to 2.6.12, at least) bugs"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  freeing unlinked file indefinitely delayed
  fix a braino in ovl_d_select_inode()
  9p: don't leave a half-initialized inode sitting around

Pull MIPS fixes from Ralf Baechle:
 "A fair number of 4.2 fixes also because Markos opened the flood gates.

   - Patch up the math used calculate the location for the page bitmap.

   - The FDC (Not what you think, FDC stands for Fast Debug Channel) IRQ
     around was causing issues on non-Malta platforms, so move the code
     to a Malta specific location.

   - A spelling fix replicated through several files.

   - Fix to the emulation of an R2 instruction for R6 cores.

   - Fix the JR emulation for R6.

   - Further patching of mindless 64 bit issues.

   - Ensure the kernel won't crash on CPUs with L2 caches with >= 8
     ways.

   - Use compat_sys_getsockopt for O32 ABI on 64 bit kernels.

   - Fix cache flushing for multithreaded cores.

   - A build fix"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: O32: Use compat_sys_getsockopt.
  MIPS: c-r4k: Extend way_string array
  MIPS: Pistachio: Support CDMM & Fast Debug Channel
  MIPS: Malta: Make GIC FDC IRQ workaround Malta specific
  MIPS: c-r4k: Fix cache flushing for MT cores
  Revert "MIPS: Kconfig: Disable SMP/CPS for 64-bit"
  MIPS: cps-vec: Use macros for various arithmetics and memory operations
  MIPS: kernel: cps-vec: Replace KSEG0 with CKSEG0
  MIPS: kernel: cps-vec: Use ta0-ta3 pseudo-registers for 64-bit
  MIPS: kernel: cps-vec: Replace mips32r2 ISA level with mips64r2
  MIPS: kernel: cps-vec: Replace 'la' macro with PTR_LA
  MIPS: kernel: smp-cps: Fix 64-bit compatibility errors due to pointer casting
  MIPS: Fix erroneous JR emulation for MIPS R6
  MIPS: Fix branch emulation for BLTC and BGEC instructions
  MIPS: kernel: traps: Fix broken indentation
  MIPS: bootmem: Don't use memory holes for page bitmap
  MIPS: O32: Do not handle require 32 bytes from the stack to be readable.
  MIPS, CPUFREQ: Fix spelling of Institute.
  MIPS: Lemote 2F: Fix build caused by recent mass rename.

Pull x86 fixes from Thomas Gleixner:

 - the high latency PIT detection fix, which slipped through the cracks
   for rc1

 - a regression fix for the early printk mechanism

 - the x86 part to plug irq/vector related hotplug races

 - move the allocation of the espfix pages on cpu hotplug to non atomic
   context.  The current code triggers a might_sleep() warning.

 - a series of KASAN fixes addressing boot crashes and usability

 - a trivial typo fix for Kconfig help text

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kconfig: Fix typo in the CONFIG_CMDLINE_BOOL help text
  x86/irq: Retrieve irq data after locking irq_desc
  x86/irq: Use proper locking in check_irq_vectors_for_cpu_disable()
  x86/irq: Plug irq vector hotplug race
  x86/earlyprintk: Allow early_printk() to use console style parameters like '115200n8'
  x86/espfix: Init espfix on the boot CPU side
  x86/espfix: Add 'cpu' parameter to init_espfix_ap()
  x86/kasan: Move KASAN_SHADOW_OFFSET to the arch Kconfig
  x86/kasan: Add message about KASAN being initialized
  x86/kasan: Fix boot crash on AMD processors
  x86/kasan: Flush TLBs after switching CR3
  x86/kasan: Fix KASAN shadow region page tables
  x86/init: Clear 'init_level4_pgt' earlier
  x86/tsc: Let high latency PIT fail fast in quick_pit_calibrate()

Pull timer fixes from Thomas Gleixner:
 "This update from the timer departement contains:

   - A series of patches which address a shortcoming in the tick
     broadcast code.

     If the broadcast device is not available or an hrtimer emulated
     broadcast device, some of the original assumptions lead to boot
     failures.  I rather plugged all of the corner cases instead of only
     addressing the issue reported, so the change got a little larger.

     Has been extensivly tested on x86 and arm.

   - Get rid of the last holdouts using do_posix_clock_monotonic_gettime()

   - A regression fix for the imx clocksource driver

   - An update to the new state callbacks mechanism for clockevents.
     This is required to simplify the conversion, which will take place
     in 4.3"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/broadcast: Prevent NULL pointer dereference
  time: Get rid of do_posix_clock_monotonic_gettime
  cris: Replace do_posix_clock_monotonic_gettime()
  tick/broadcast: Unbreak CONFIG_GENERIC_CLOCKEVENTS=n build
  tick/broadcast: Handle spurious interrupts gracefully
  tick/broadcast: Check for hrtimer broadcast active early
  tick/broadcast: Return busy when IPI is pending
  tick/broadcast: Return busy if periodic mode and hrtimer broadcast
  tick/broadcast: Move the check for periodic mode inside state handling
  tick/broadcast: Prevent deep idle if no broadcast device available
  tick/broadcast: Make idle check independent from mode and config
  tick/broadcast: Sanity check the shutdown of the local clock_event
  tick/broadcast: Prevent hrtimer recursion
  clockevents: Allow set-state callbacks to be optional
  clocksource/imx: Define clocksource for mx27

Pull irq fix from Thomas Gleixner:
 "A single fix for a cpu hotplug race vs. interrupt descriptors:

  Prevent irq setup/teardown across the cpu starting/dying parts of cpu
  hotplug so that the starting/dying cpu has a stable view of the
  descriptor space.  This has been an issue for all architectures in the
  cpu dying phase, where interrupts are migrated away from the dying
  cpu.  In the starting phase its mostly a x86 issue vs the vector space
  update"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hotplug: Prevent alloc/free of irq descriptors during cpu up/down

	Normally opening a file, unlinking it and then closing will have
the inode freed upon close() (provided that it's not otherwise busy and
has no remaining links, of course).  However, there's one case where that
does *not* happen.  Namely, if you open it by fhandle with cold dcache,
then unlink() and close().

	In normal case you get d_delete() in unlink(2) notice that dentry
is busy and unhash it; on the final dput() it will be forcibly evicted from
dcache, triggering iput() and inode removal.  In this case, though, we end
up with *two* dentries - disconnected (created by open-by-fhandle) and
regular one (used by unlink()).  The latter will have its reference to inode
dropped just fine, but the former will not - it's considered hashed (it
is on the ->s_anon list), so it will stay around until the memory pressure
will finally do it in.  As the result, we have the final iput() delayed
indefinitely.  It's trivial to reproduce -

void flush_dcache(void)
{
        system("mount -o remount,rw /");
}

static char buf[20 * 1024 * 1024];

main()
{
        int fd;
        union {
                struct file_handle f;
                char buf[MAX_HANDLE_SZ];
        } x;
        int m;

        x.f.handle_bytes = sizeof(x);
        chdir("/root");
        mkdir("foo", 0700);
        fd = open("foo/bar", O_CREAT | O_RDWR, 0600);
        close(fd);
        name_to_handle_at(AT_FDCWD, "foo/bar", &x.f, &m, 0);
        flush_dcache();
        fd = open_by_handle_at(AT_FDCWD, &x.f, O_RDWR);
        unlink("foo/bar");
        write(fd, buf, sizeof(buf));
        system("df .");			/* 20Mb eaten */
        close(fd);
        system("df .");			/* should've freed those 20Mb */
        flush_dcache();
        system("df .");			/* should be the same as #2 */
}

will spit out something like
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 303843      1131 100% /
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 303843      1131 100% /
Filesystem     1K-blocks   Used Available Use% Mounted on
/dev/root         322023 283282     21692  93% /
- inode gets freed only when dentry is finally evicted (here we trigger
than by remount; normally it would've happened in response to memory
pressure hell knows when).

Cc: stable@vger.kernel.org # v2.6.38+; earlier ones need s/kill_it/unhash_it/
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

when opening a directory we want the overlayfs inode, not one from
the topmost layer.
Reported-By: Andrey Jr. Melnikov <temnota.am@gmail.com>
Tested-By: Andrey Jr. Melnikov <temnota.am@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org # all branches
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull libnvdimm fixes from Dan Williams:
 "1) Fixes for a handful of smatch reports (Thanks Dan C.!) and minor
     bug fixes (patches 1-6)

  2) Correctness fixes to the BLK-mode nvdimm driver (patches 7-10).

     Granted these are slightly large for a -rc update.  They have been
     out for review in one form or another since the end of May and were
     deferred from the merge window while we settled on the "PMEM API"
     for the PMEM-mode nvdimm driver (ie memremap_pmem, memcpy_to_pmem,
     and wmb_pmem).

     Now that those apis are merged we implement them in the BLK driver
     to guarantee that mmio aperture moves stay ordered with respect to
     incoming read/write requests, and that writes are flushed through
     those mmio-windows and platform-buffers to be persistent on media.

  These pass the sub-system unit tests with the updates to
  tools/testing/nvdimm, and have received a successful build-report from
  the kbuild robot (468 configs).

  With acks from Rafael for the touches to drivers/acpi/"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm:
  nfit: add support for NVDIMM "latch" flag
  nfit: update block I/O path to use PMEM API
  tools/testing/nvdimm: add mock acpi_nfit_flush_address entries to nfit_test
  tools/testing/nvdimm: fix return code for unimplemented commands
  tools/testing/nvdimm: mock ioremap_wt
  pmem: add maintainer for include/linux/pmem.h
  nfit: fix smatch "use after null check" report
  nvdimm: Fix return value of nvdimm_bus_init() if class_create() fails
  libnvdimm: smatch cleanups in __nd_ioctl
  sparse: fix misplaced __pmem definition

Pull i2c fixes from Wolfram Sang:
 "Mostly slight adjusments for new drivers, but also one core fix for
  which finally the dependencies are now available as well"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: Mark instantiated device nodes with OF_POPULATE
  i2c: jz4780: Fix return value if probe fails
  i2c: xgene-slimpro: Fix missing mbox_free_channel call in probe error path
  i2c: I2C_MT65XX should depend on HAS_DMA

Pull input fixes from Dmitry Torokhov:
 "A fix (revert) for a recent regression in Synaptics driver and a fix
  for Elan i2c touchpad driver"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Revert "Input: synaptics - allocate 3 slots to keep stability in image sensors"
  Input: elan_i2c - change the hover event from MT to ST

Pull clk fixes from Stephen Boyd:
 "A small set of fixes for problems found by smatch in new drivers that
  we added this rc and a handful of driver fixes that came in during the
  merge window"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  drivers: clk: st: Incorrect register offset used for lock_status
  clk: mediatek: mt8173: Fix enabling of critical clocks
  drivers: clk: st: Fix mux bit-setting for Cortex A9 clocks
  drivers: clk: st: Add CLK_GET_RATE_NOCACHE flag to clocks
  drivers: clk: st: Fix flexgen lock init
  drivers: clk: st: Fix FSYN channel values
  drivers: clk: st: Remove unused code
  clk: qcom: Use parent rate when set rate to pixel RCG clock
  clk: at91: do not leak resources
  clk: stm32: Fix out-by-one error path in the index lookup
  clk: iproc: fix bit manipulation arithmetic
  clk: iproc: fix memory leak from clock name

Pull drm fixes from Dave Airlie:
 "A bunch of fixes for radeon, intel, omap and one amdkfd fix.

  Radeon fixes are all over, but it does fix some cursor corruption
  across suspend/resume.  i915 should fix the second warn you were
  seeing, so let us know if not.  omap is a bunch of small fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (28 commits)
  drm/radeon: disable vce init on cayman (v2)
  drm/amdgpu: fix timeout calculation
  drm/radeon: check if BO_VA is set before adding it to the invalidation list
  drm/radeon: allways add the VM clear duplicate
  Revert "Revert "drm/radeon: dont switch vt on suspend""
  drm/radeon: Fold radeon_set_cursor() into radeon_show_cursor()
  drm/radeon: unpin cursor BOs on suspend and pin them again on resume (v2)
  drm/radeon: Clean up reference counting and pinning of the cursor BOs
  drm/amdkfd: validate pdd where it acquired first
  Revert "drm/i915: Allocate context objects from stolen"
  drm/i915: Declare the swizzling unknown for L-shaped configurations
  drm/radeon: fix underflow in r600_cp_dispatch_texture()
  drm/radeon: default to 2048 MB GART size on SI+
  drm/radeon: fix HDP flushing
  drm/radeon: use RCU query for GEM_BUSY syscall
  drm/amdgpu: Handle irqs only based on irq ring, not irq status regs.
  drm/radeon: Handle irqs only based on irq ring, not irq status regs.
  drm/i915: Use crtc_state->active in primary check_plane func
  drm/i915: Check crtc->active in intel_crtc_disable_planes
  drm/i915: Restore all GGTT VMAs on resume
  ...

Pull selinux fixes from James Morris.

* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  selinux: fix mprotect PROT_EXEC regression caused by mm change
  selinux: don't waste ebitmap space when importing NetLabel categories

Pull btrfs fixes from Chris Mason:
 "This is an assortment of fixes.  Most of the commits are from Filipe
  (fsync, the inode allocation cache and a few others).  Mark kicked in
  a series fixing corners in the extent sharing ioctls, and everyone
  else fixed up on assorted other problems"

* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix wrong check for btrfs_force_chunk_alloc()
  Btrfs: fix warning of bytes_may_use
  Btrfs: fix hang when failing to submit bio of directIO
  Btrfs: fix a comment in inode.c:evict_inode_truncate_pages()
  Btrfs: fix memory corruption on failure to submit bio for direct IO
  btrfs: don't update mtime/ctime on deduped inodes
  btrfs: allow dedupe of same inode
  btrfs: fix deadlock with extent-same and readpage
  btrfs: pass unaligned length to btrfs_cmp_data()
  Btrfs: fix fsync after truncate when no_holes feature is enabled
  Btrfs: fix fsync xattr loss in the fast fsync path
  Btrfs: fix fsync data loss after append write
  Btrfs: fix crash on close_ctree() if cleaner starts new transaction
  Btrfs: fix race between caching kthread and returning inode to inode cache
  Btrfs: use kmem_cache_free when freeing entry in inode cache
  Btrfs: fix race between balance and unused block group deletion
  btrfs: add error handling for scrub_workers_get()
  btrfs: cleanup noused initialization of dev in btrfs_end_bio()
  btrfs: qgroup: allow user to clear the limitation on qgroup

Pull ARM SoC fixes from Kevin Hilman:
 "A fairly random colletion of fixes based on -rc1 for OMAP, sunxi and
  prima2 as well as a few arm64-specific DT fixes.

  This series also includes a late to support a new Allwinner (sunxi)
  SoC, but since it's rather simple and isolated to the
  platform-specific code, it's included it for this -rc"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm64: dts: add device tree for ARM SMM-A53x2 on LogicTile Express 20MG
  arm: dts: vexpress: add missing CCI PMU device node to TC2
  arm: dts: vexpress: describe all PMUs in TC2 dts
  GICv3: Add ITS entry to THUNDER dts
  arm64: dts: Add poweroff button device node for APM X-Gene platform
  ARM: dts: am4372.dtsi: disable rfbi
  ARM: dts: am57xx-beagle-x15: Provide supply for usb2_phy2
  ARM: dts: am4372: Add emif node
  Revert "ARM: dts: am335x-boneblack: disable RTC-only sleep"
  ARM: sunxi: Enable simplefb in the defconfig
  ARM: Remove deprecated symbol from defconfig files
  ARM: sunxi: Add Machine support for A33
  ARM: sunxi: Introduce Allwinner H3 support
  Documentation: sunxi: Update Allwinner SoC documentation
  ARM: prima2: move to use REGMAP APIs for rtciobrg
  ARM: dts: atlas7: add pinctrl and gpio descriptions
  ARM: OMAP2+: Remove unnessary return statement from the void function, omap2_show_dma_caps
  memory: omap-gpmc: Fix parsing of devices

Dan reported that the recent changes to the broadcast code introduced
a potential NULL dereference.

Add the proper check.

Fixes: e0454311 "tick/broadcast: Sanity check the shutdown of the local clock_event"
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Pull parisc fixes from Helge Deller:
 "We have one important patch from Dave Anglin and myself which fixes
  PTE/TLB race conditions which caused random segmentation faults on our
  debian buildd servers, and one patch from Alex Ivanov which speeds up
  the graphical text console on the STI framebuffer driver"

* 'parisc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix some PTE/TLB race conditions and optimize __flush_tlb_range based on timing results
  stifb: Implement hardware accelerated copyarea

commit 66fc1303 ("mm: shmem_zero_setup
skip security check and lockdep conflict with XFS") caused a regression
for SELinux by disabling any SELinux checking of mprotect PROT_EXEC on
shared anonymous mappings.  However, even before that regression, the
checking on such mprotect PROT_EXEC calls was inconsistent with the
checking on a mmap PROT_EXEC call for a shared anonymous mapping.  On a
mmap, the security hook is passed a NULL file and knows it is dealing
with an anonymous mapping and therefore applies an execmem check and no
file checks.  On a mprotect, the security hook is passed a vma with a
non-NULL vm_file (as this was set from the internally-created shmem
file during mmap) and therefore applies the file-based execute check
and no execmem check.  Since the aforementioned commit now marks the
shmem zero inode with the S_PRIVATE flag, the file checks are disabled
and we have no checking at all on mprotect PROT_EXEC.  Add a test to
the mprotect hook logic for such private inodes, and apply an execmem
check in that case.  This makes the mmap and mprotect checking
consistent for shared anonymous mappings, as well as for /dev/zero and
ashmem.

Cc: <stable@vger.kernel.org> # 4.1.x
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

Pull arm64 fixes and clean-up from Catalin Marinas:
 - ACPI fix when checking the validity of the GICC MADT subtable
 - handle debug exceptions in the el*_inv exception entries
 - remove pointless register assignment in two compat syscall wrappers
 - unnecessary include path
 - defconfig update

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: entry32: remove pointless register assignment
  arm64: entry: handle debug exceptions in el*_inv
  arm64: Keep the ARM64 Kconfig selects sorted
  ACPI / ARM64 : use the new BAD_MADT_GICC_ENTRY macro
  ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro
  arm64: defconfig: Add Ceva ahci to the defconfig
  arm64: remove another unnecessary libfdt include path

The increased use of pdtlb/pitlb instructions seemed to increase the
frequency of random segmentation faults building packages. Further, we
had a number of cases where TLB inserts would repeatedly fail and all
forward progress would stop. The Haskell ghc package caused a lot of
trouble in this area. The final indication of a race in pte handling was
this syslog entry on sibaris (C8000):

 swap_free: Unused swap offset entry 00000004
 BUG: Bad page map in process mysqld  pte:00000100 pmd:019bbec5
 addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464
 CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1
 Backtrace:
  [<0000000040173eb0>] show_stack+0x20/0x38
  [<0000000040444424>] dump_stack+0x9c/0x110
  [<00000000402a0d38>] print_bad_pte+0x1a8/0x278
  [<00000000402a28b8>] unmap_single_vma+0x3d8/0x770
  [<00000000402a4090>] zap_page_range+0xf0/0x198
  [<00000000402ba2a4>] SyS_madvise+0x404/0x8c0

Note that the pte value is 0 except for the accessed bit 0x100. This bit
shouldn't be set without the present bit.

It should be noted that the madvise system call is probably a trigger for many
of the random segmentation faults.

In looking at the kernel code, I found the following problems:

1) The pte_clear define didn't take TLB lock when clearing a pte.
2) We didn't test pte present bit inside lock in exception support.
3) The pte and tlb locks needed to merged in order to ensure consistency
between page table and TLB. This also has the effect of serializing TLB
broadcasts on SMP systems.

The attached change implements the above and a few other tweaks to try
to improve performance. Based on the timing code, TLB purges are very
slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it
beneficial to test the split_tlb variable to avoid duplicate purges.
Probably, all PA 2.0 machines have combined TLBs.

I dropped using __flush_tlb_range in flush_tlb_mm as I realized all
applications and most threads have a stack size that is too large to
make this useful. I added some comments to this effect.

Since implementing 1 through 3, I haven't had any random segmentation
faults on mx3210 (rp3440) in about one week of building code and running
as a Debian buildd.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Helge Deller <deller@gmx.de>

This patch adds hardware assisted scrolling. The code is based upon the
following investigation: https://parisc.wiki.kernel.org/index.php/NGLE#Blitter

A simple 'time ls -la /usr/bin' test shows 1.6x speed increase over soft
copy and 2.3x increase over FBINFO_READS_FAST (prefer soft copy over
screen redraw) on Artist framebuffer.
Signed-off-by: Alex Ivanov <lausgans@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

Pull powerpc fixes from Michael Ellerman:
 - opal-prd mmap fix from Vaidy
 - set kernel taint for MCEs from Daniel
 - alignment exception description from Anton
 - ppc4xx_hsta_msi build fix from Daniel
 - opal-elog interrupt fix from Alistair
 - core_idle_state race fix from Shreyas
 - hv-24x7 lockdep fix from Sukadev
 - multiple cxl fixes from Daniel, Ian, Mikey & Maninder
 - update MAINTAINERS to point at shared tree

* tag 'powerpc-4.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  cxl: Check if afu is not null in cxl_slbia
  powerpc: Update MAINTAINERS to point at shared tree
  powerpc/perf/24x7: Fix lockdep warning
  cxl: Fix off by one error allowing subsequent mmap page to be accessed
  cxl: Fail mmap if requested mapping is larger than assigned problem state area
  cxl: Fix refcounting in kernel API
  powerpc/powernv: Fix race in updating core_idle_state
  powerpc/powernv: Fix opal-elog interrupt handler
  powerpc/ppc4xx_hsta_msi: Include ppc-pci.h to fix reference to hose_list
  powerpc: Add plain English description for alignment exception oopses
  cxl: Test the correct mmio space before unmapping
  powerpc: Set the correct kernel taint on machine check errors
  cxl/vphb.c: Use phb pointer after NULL check
  powerpc/powernv: Fix vma page prot flags in opal-prd driver

Add support in the NFIT BLK I/O path for the "latch" flag
defined in the "Get Block NVDIMM Flags" _DSM function:

http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

This flag requires the driver to read back the command register after it
is written in the block I/O path.  This ensures that the hardware has
fully processed the new command and moved the aperture appropriately.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Update the nfit block I/O path to use the new PMEM API and to adhere to
the read/write flows outlined in the "NVDIMM Block Window Driver
Writer's Guide":

http://pmem.io/documents/NVDIMM_Driver_Writers_Guide.pdf

This includes adding support for targeted NVDIMM flushes called "flush
hints" in the ACPI 6.0 specification:

http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf

For performance and media durability the mapping for a BLK aperture is
moved to a write-combining mapping which is consistent with
memcpy_to_pmem() and wmb_blk().
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

In preparation for fixing the BLK path to properly use "directed
pcommit" enable the unit test infrastructure to emit mock "flush"
tables.  Writes to these flush addresses trigger a memory controller to
flush its internal buffers to persistent media, similar to the x86
"pcommit" instruction.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>