commit 5a60e87603c4c533492c515b7f62578189b03c9c upstream.

rbd_obj_request_create() is called on the main I/O path, so we need to
use GFP_NOIO to make sure allocation doesn't blow back on us.  Not all
callers need this, but I'm still hardcoding the flag inside rather than
making it a parameter because a) this is going to stable, and b) those
callers shouldn't really use rbd_obj_request_create() and will be fixed
in the future.

More memory allocation fixes will follow.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 4d4e41aef9429872ea3b105e83426941f7185ab6 upstream.

If there are too many pending per work I/O, too many
high priority work thread can be generated so that
system performance can be effected.

This patch limits the max_active parameter of workqueue as 16.

This patch fixes Fedora 22 live booting performance
regression when it is booted from squashfs over dm
based on loop, and looks the following reasons are
related with the problem:

- not like other filesyststems(such as ext4), squashfs
is a bit special, and I observed that increasing I/O jobs
to access file in squashfs only improve I/O performance a
little, but it can make big difference for ext4

- nested loop: both squashfs.img and ext3fs.img are mounted
as loop block, and ext3fs.img is inside the squashfs

- during booting, lots of tasks may run concurrently

Fixes: b5dd2f6047ca108001328aac0e8588edd15f1778
Cc: Justin M. Forbes <jforbes@fedoraproject.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f4aa4c7bbac6c4afdd4adccf90898c1a3685396d upstream.

Documentation/workqueue.txt:
	If there is dependency among multiple work items used
	during memory reclaim, they should be queued to separate
	wq each with WQ_MEM_RECLAIM.

Loop devices can be stacked, so we have to convert to per-device
workqueue. One example is Fedora live CD.

Fixes: b5dd2f6047ca108001328aac0e8588edd15f1778
Cc: Justin M. Forbes <jforbes@fedoraproject.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull block layer fixes from Jens Axboe:
 "Remember about a week ago when I sent the last pull request for 4.1?
  Well, I lied.  Now, I don't want to shift the blame, but Dan, Ming,
  and Richard made a liar out of me.

  Here are three small patches that should go into 4.1.  More
  specifically, this pull request contains:

   - A Kconfig dependency for the pmem block driver, so it can't be
     selected if HAS_IOMEM isn't availble.  From Richard Weinberger.

   - A fix for genhd, making the ext_devt_lock softirq safe.  This makes
     lockdep happier, since we also end up grabbing this lock on release
     off the softirq path.  From Dan Williams.

   - A blk-mq software queue release fix from Ming Lei.

  Last two are headed to stable, first fixes an issue introduced in this
  cycle"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: pmem: Add dependency on HAS_IOMEM
  block: fix ext_dev_lock lockdep report
  blk-mq: free hctx->ctxs in queue's release handler

Not all architectures have io memory.

Fixes:
drivers/block/pmem.c: In function ‘pmem_alloc’:
drivers/block/pmem.c:146:2: error: implicit declaration of function ‘ioremap_nocache’ [-Werror=implicit-function-declaration]
  pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size);
  ^
drivers/block/pmem.c:146:18: warning: assignment makes pointer from integer without a cast [enabled by default]
  pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size);
                  ^
drivers/block/pmem.c:182:2: error: implicit declaration of function ‘iounmap’ [-Werror=implicit-function-declaration]
  iounmap(pmem->virt_addr);
  ^

Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Clear zram disk io accounting when resetting the zram device.  Otherwise
the residual io accounting stat will affect the diskstat in the next
zram active cycle.

Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A recent change to the ioctl handling caused a new harmless
warning in the NVMe driver on all 32-bit machines:

drivers/block/nvme-core.c: In function 'nvme_submit_io':
drivers/block/nvme-core.c:1794:29: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

In order to shup up that warning, this introduces a new
temporary variable that uses a double cast to extract
the pointer from an __u64 structure member.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: a67a95134ff ("NVMe: Meta data handling through submit io ioctl")
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

If userspace asks for an INQUIRY buffer smaller than 36 bytes, the SCSI
translation layer will happily write past the end of the INQUIRY buffer
allocation.

This is fairly easily reproducible by running the libiscsi test
suite and then starting an xfstests run.

Fixes: 4f1982 ("NVMe: Update SCSI Inquiry VPD 83h translation")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Pull block fixes from Jens Axboe:
 "A collection of fixes since the merge window;

   - fix for a double elevator module release, from Chao Yu.  Ancient bug.

   - the splice() MORE flag fix from Christophe Leroy.

   - a fix for NVMe, fixing a patch that went in in the merge window.
     From Keith.

   - two fixes for blk-mq CPU hotplug handling, from Ming Lei.

   - bdi vs blockdev lifetime fix from Neil Brown, fixing and oops in md.

   - two blk-mq fixes from Shaohua, fixing a race on queue stop and a
     bad merge issue with FUA writes.

   - division-by-zero fix for writeback from Tejun.

   - a block bounce page accounting fix, making sure we inc/dec after
     bouncing so that pre/post IO pages match up.  From Wang YanQing"

* 'for-linus' of git://git.kernel.dk/linux-block:
  splice: sendfile() at once fails for big files
  blk-mq: don't lose requests if a stopped queue restarts
  blk-mq: fix FUA request hang
  block: destroy bdi before blockdev is unregistered.
  block:bounce: fix call inc_|dec_zone_page_state on different pages confuse value of NR_BOUNCE
  elevator: fix double release of elevator module
  writeback: use |1 instead of +1 to protect against div by zero
  blk-mq: fix CPU hotplug handling
  blk-mq: fix race between timeout and CPU hotplug
  NVMe: Fix VPD B0 max sectors translation

Pull xen bug fixes from David Vrabel:

 - fix blkback regression if using persistent grants

 - fix various event channel related suspend/resume bugs

 - fix AMD x86 regression with X86_BUG_SYSRET_SS_ATTRS

 - SWIOTLB on ARM now uses frames <4 GiB (if available) so device only
   capable of 32-bit DMA work.

* tag 'for-linus-4.1b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: Add __GFP_DMA flag when xen_swiotlb_init gets free pages on ARM
  hypervisor/x86/xen: Unset X86_BUG_SYSRET_SS_ATTRS on Xen PV guests
  xen/events: Set irq_info->evtchn before binding the channel to CPU in __startup_pirq()
  xen/console: Update console event channel on resume
  xen/xenbus: Update xenbus event channel on resume
  xen/events: Clear cpu_evtchn_mask before resuming
  xen-pciback: Add name prefix to global 'permissive' variable
  xen: Suspend ticks on all CPUs during suspend
  xen/grant: introduce func gnttab_unmap_refs_sync()
  xen/blkback: safely unmap purge persistent grants