The last from guest transmitted request gives no indication about the
minimum amount of credit that the guest might need to send a packet
since the last packet might have been a small one.

Instead allow for the worst case 128 KiB packet.

This is part of XSA155.

CC: stable@vger.kernel.org
Reviewed-by: NWei Liu <wei.liu2@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When a CPU is offlined, there may be unprocessed events on a port for
that CPU.  If the port is subsequently reused on a different CPU, it
could be in an unexpected state with the link bit set, resulting in
interrupts being missed. Fix this by consuming any unprocessed events
for a particular CPU when that CPU dies.
Signed-off-by: NRoss Lagerwall <ross.lagerwall@citrix.com>
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

If more than 1024 event channels are bound to a evtchn device then it
possible (even with well behaved applications) for the ring to
overflow and events to be lost (reported as an -EFBIG error).

Dynamically increase the size of the ring so there is always enough
space for all bound events.  Well behaved applicables that only unmask
events after draining them from the ring can thus no longer lose
events.

However, an application could unmask an event before draining it,
allowing multiple entries per port to accumulate in the ring, and a
overflow could still occur.  So the overflow detection and reporting
is retained.

The ring size is initially only 64 entries so the common use case of
an application only binding a few events will use less memory than
before.  The ring size may grow to 512 KiB (enough for all 2^17
possible channels).  This order 7 kmalloc() may fail due to memory
fragmentation, so we fall back to trying vmalloc().
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NAndrew Cooper <andrew.cooper3@citrix.com>

After commit 8c058b0b ("x86/irq: Probe for PIC presence before
allocating descs for legacy IRQs") early_irq_init() will no longer
preallocate descriptors for legacy interrupts if PIC does not
exist, which is the case for Xen PV guests.

Therefore we may need to allocate those descriptors ourselves.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

Doing so will cause the grant to be unmapped and then, during
fault handling, the fault to be mistakenly treated as NUMA hint
fault.

In addition, even if those maps could partcipate in NUMA
balancing, it wouldn't provide any benefit since we are unable
to determine physical page's node (even if/when VNUMA is
implemented).

Marking grant maps' VMAs as VM_IO will exclude them from being
part of NUMA balancing.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

When offlining a cpu, instead of cpu_down, call device_offline, which
also takes care of updating the cpu.dev.offline field. This keeps the
sysfs file /sys/devices/system/cpu/cpuN/online, up to date.  Also move
the call to disable_hotplug_cpu, because it makes more sense to have it
there.

We don't call device_online at cpu-hotplug time, because that would
immediately take the cpu online, while we want to retain the current
behaviour: the user needs to explicitly enable the cpu after it has
been hotplugged.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
CC: konrad.wilk@oracle.com
CC: boris.ostrovsky@oracle.com
CC: david.vrabel@citrix.com

Build cpu_hotplug for ARM and ARM64 guests.

Rename arch_(un)register_cpu to xen_(un)register_cpu and provide an
empty implementation on ARM and ARM64. On x86 just call
arch_(un)register_cpu as we are already doing.

Initialize cpu_hotplug on ARM.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>

The PV ring may use multiple grants and expect them to be mapped
contiguously in the virtual memory.

Although, the current code is relying on a Linux page will be mapped to
a single grant. On build where Linux is using a different page size than
the grant (i.e other than 4KB), the grant will always be mapped on the
first 4KB of each Linux page which make the final ring not contiguous in
the memory.

This can be fixed by mapping multiple grant in a same Linux page.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

With the 64KB page granularity support on ARM64, a Linux page may be
split accross multiple grant.

Currently we have the helper gnttab_foreach_grant_in_grant to break a
Linux page based on an offset and a len, but it doesn't fit when we only
have a number of grants in hand.

Introduce a new helper which take an array of Linux page and a number of
grant and will figure out the address of each grant.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

Linux may use a different page size than the size of grant. So make
clear that the order is actually in number of grant.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The type of the item in frame_list is xen_pfn_t which is not an unsigned
long on ARM but an uint64_t.

With the current computation, the size of frame_list will be 2 *
PAGE_SIZE rather than PAGE_SIZE.

I bet it's just mistake when the type has been switched from "unsigned
long" to "xen_pfn_t" in commit 965c0aaa
"xen: balloon: use correct type for frame_list".
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

Swiotlb is used on ARM64 to support DMA on platform where devices are
not protected by an SMMU. Furthermore it's only enabled for DOM0.

While Xen is always using 4KB page granularity in the stage-2 page table,
Linux ARM64 may either use 4KB or 64KB. This means that a Linux page
can be spanned accross multiple Xen page.

The Swiotlb code has to validate that the buffer used for DMA is
physically contiguous in the memory. As a Linux page can't be shared
between local memory and foreign page by design (the balloon code always
removing entirely a Linux page), the changes in the code are very
minimal because we only need to check the first Xen PFN.

Note that it may be possible to optimize the function
check_page_physically_contiguous to avoid looping over every Xen PFN
for local memory. Although I will let this optimization for a follow-up.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

With 64KB page granularity support, the frame number will be different.

It will be easier to modify the behavior in a single place rather than
in each caller.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The hypercall interface (as well as the toolstack) is always using 4KB
page granularity. When the toolstack is asking for mapping a series of
guest PFN in a batch, it expects to have the page map contiguously in
its virtual memory.

When Linux is using 64KB page granularity, the privcmd driver will have
to map multiple Xen PFN in a single Linux page.

Note that this solution works on page granularity which is a multiple of
4KB.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The PV network protocol is using 4KB page granularity. The goal of this
patch is to allow a Linux using 64KB page granularity working as a
network backend on a non-modified Xen.

It's only necessary to adapt the ring size and break skb data in small
chunk of 4KB. The rest of the code is relying on the grant table code.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NWei Liu <wei.liu2@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The PV network protocol is using 4KB page granularity. The goal of this
patch is to allow a Linux using 64KB page granularity using network
device on a non-modified Xen.

It's only necessary to adapt the ring size and break skb data in small
chunk of 4KB. The rest of the code is relying on the grant table code.

Note that we allocate a Linux page for each rx skb but only the first
4KB is used. We may improve the memory usage by extending the size of
the rx skb.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The PV block protocol is using 4KB page granularity. The goal of this
patch is to allow a Linux using 64KB page granularity behaving as a
block backend on a non-modified Xen.

It's only necessary to adapt the ring size and the number of request per
indirect frames. The rest of the code is relying on the grant table
code.

Note that the grant table code is allocating a Linux page per grant
which will result to waste 6OKB for every grant when Linux is using 64KB
page granularity. This could be improved by sharing the page between
multiple grants.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Acked-by: N"Roger Pau Monné" <roger.pau@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The PV block protocol is using 4KB page granularity. The goal of this
patch is to allow a Linux using 64KB page granularity using block
device on a non-modified Xen.

The block API is using segment which should at least be the size of a
Linux page. Therefore, the driver will have to break the page in chunk
of 4K before giving the page to the backend.

When breaking a 64KB segment in 4KB chunks, it is possible that some
chunks are empty. As the PV protocol always require to have data in the
chunk, we have to count the number of Xen page which will be in use and
avoid sending empty chunks.

Note that, a pre-defined number of grants are reserved before preparing
the request. This pre-defined number is based on the number and the
maximum size of the segments. If each segment contains a very small
amount of data, the driver may reserve too many grants (16 grants is
reserved per segment with 64KB page granularity).

Furthermore, in the case of persistent grants we allocate one Linux page
per grant although only the first 4KB of the page will be effectively
in use. This could be improved by sharing the page with multiple grants.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Acked-by: NRoger Pau Monné <roger.pau@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The Xen interface is using 4KB page granularity. This means that each
grant is 4KB.

The current implementation allocates a Linux page per grant. On Linux
using 64KB page granularity, only the first 4KB of the page will be
used.

We could decrease the memory wasted by sharing the page with multiple
grant. It will require some care with the {Set,Clear}ForeignPage macro.

Note that no changes has been made in the x86 code because both Linux
and Xen will only use 4KB page granularity.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

Only use the first 4KB of the page to store the events channel info. It
means that we will waste 60KB every time we allocate page for:
     * control block: a page is allocating per CPU
     * event array: a page is allocating everytime we need to expand it

I think we can reduce the memory waste for the 2 areas by:

    * control block: sharing between multiple vCPUs. Although it will
    require some bookkeeping in order to not free the page when the CPU
    goes offline and the other CPUs sharing the page still there

    * event array: always extend the array event by 64K (i.e 16 4K
    chunk). That would require more care when we fail to expand the
    event channel.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

For ARM64 guests, Linux is able to support either 64K or 4K page
granularity. Although, the hypercall interface is always based on 4K
page granularity.

With 64K page granularity, a single page will be spread over multiple
Xen frame.

To avoid splitting the page into 4K frame, take advantage of the
extent_order field to directly allocate/free chunk of the Linux page
size.

Note that PVMMU is only used for PV guest (which is x86) and the page
granularity is always 4KB. Some BUILD_BUG_ON has been added to ensure
that because the code has not been modified.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The console ring is always based on the page granularity of Xen.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

All the ring (xenstore, and PV rings) are always based on the page
granularity of Xen.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

On ARM all dma-capable devices on a same platform may not be protected
by an IOMMU. The DMA requests have to use the BFN (i.e MFN on ARM) in
order to use correctly the device.

While the DOM0 memory is allocated in a 1:1 fashion (PFN == MFN), grant
mapping will screw this contiguous mapping.

When Linux is using 64KB page granularitary, the page may be split
accross multiple non-contiguous MFN (Xen is using 4KB page
granularity). Therefore a DMA request will likely fail.

Checking that a 64KB page is using contiguous MFN is tedious. For
now, always says that biovec are not mergeable.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

Prepare the code to support 64KB page granularity. The first
implementation will use a full Linux page per indirect and persistent
grant. When non-persistent grant is used, each page of a bio request
may be split in multiple grant.

Furthermore, the field page of the grant structure is only used to copy
data from persistent grant or indirect grant. Avoid to set it for other
use case as it will have no meaning given the page will be split in
multiple grant.

Provide 2 functions, to setup indirect grant, the other for bio page.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Acked-by: NRoger Pau Monné <roger.pau@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

All the usage of the field pfn are done using the same idiom:

pfn_to_page(grant->pfn)

This will  return always the same page. Store directly the page in the
grant to clean up the code.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Acked-by: NRoger Pau Monné <roger.pau@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

Currently, blkif_queue_request has 2 distinct execution path:
    - Send a discard request
    - Send a read/write request

The function is also allocating grants to use for generating the
request. Although, this is only used for read/write request.

Rather than having a function with 2 distinct execution path, separate
the function in 2. This will also remove one level of tabulation.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NRoger Pau Monné <roger.pau@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

Currently, a grant is always based on the Xen page granularity (i.e
4KB). When Linux is using a different page granularity, a single page
will be split between multiple grants.

The new helpers will be in charge of splitting the Linux page into grants
and call a function given by the caller on each grant.

Also provide an helper to count the number of grants within a given
contiguous region.

Note that the x86/include/asm/xen/page.h is now including
xen/interface/grant_table.h rather than xen/grant_table.h. It's
necessary because xen/grant_table.h depends on asm/xen/page.h and will
break the compilation. Furthermore, only definition in
interface/grant_table.h is required.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

The skb doesn't change within the function. Therefore it's only
necessary to check if we need GSO once at the beginning.
Signed-off-by: NJulien Grall <julien.grall@citrix.com>
Acked-by: NWei Liu <wei.liu2@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

Pages returned by alloc_xenballooned_pages() will be used for grant
mapping which will call set_phys_to_machine() (in PV guests).

Ballooned pages are set as INVALID_P2M_ENTRY in the p2m and thus may
be using the (shared) missing tables and a subsequent
set_phys_to_machine() will need to allocate new tables.

Since the grant mapping may be done from a context that cannot sleep,
the p2m entries must already be allocated.
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NDaniel Kiper <daniel.kiper@oracle.com>

alloc_xenballooned_pages() is used to get ballooned pages to back
foreign mappings etc.  Instead of having to balloon out real pages,
use (if supported) hotplugged memory.

This makes more memory available to the guest and reduces
fragmentation in the p2m.

This is only enabled if the xen.balloon.hotplug_unpopulated sysctl is
set to 1.  This sysctl defaults to 0 in case the udev rules to
automatically online hotplugged memory do not exist.
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NDaniel Kiper <daniel.kiper@oracle.com>
---
v3:
- Add xen.balloon.hotplug_unpopulated sysctl to enable use of hotplug
  for unpopulated pages.

All users of alloc_xenballoon_pages() wanted low memory pages, so
remove the option for high memory.
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NDaniel Kiper <daniel.kiper@oracle.com>

Now that we track the total number of pages (included hotplugged
regions), it is easy to determine if more memory needs to be
hotplugged.

Add a new BP_WAIT state to signal that the balloon process needs to
wait until kicked by the memory add notifier (when the new section is
onlined by userspace).
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NDaniel Kiper <daniel.kiper@oracle.com>
---
v3:
- Return BP_WAIT if enough sections are already hotplugged.

v2:
- New BP_WAIT status after adding new memory sections.

The stats used for memory hotplug make no sense and are fiddled with
in odd ways.  Remove them and introduce total_pages to track the total
number of pages (both populated and unpopulated) including those within
hotplugged regions (note that this includes not yet onlined pages).

This will be used in a subsequent commit (xen/balloon: only hotplug
additional memory if required) when deciding whether additional memory
needs to be hotplugged.
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NDaniel Kiper <daniel.kiper@oracle.com>

Instead of placing hotplugged memory at the end of RAM (which may
conflict with PCI devices or reserved regions) use allocate_resource()
to get a new, suitably aligned resource that does not conflict.
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: NDaniel Kiper <daniel.kiper@oracle.com>
---
v3:
- Remove stale comment.

ACPI SSCN/FMCN methods were originally added because then the platform can
provide the most accurate HCNT/LCNT values to the driver. However, this
seems not to be true for Dell Inspiron 7348 where using these causes the
touchpad to fail in boot:

  i2c_hid i2c-DLL0675:00: failed to retrieve report from device.
  i2c_designware INT3433:00: i2c_dw_handle_tx_abort: lost arbitration
  i2c_hid i2c-DLL0675:00: failed to retrieve report from device.
  i2c_designware INT3433:00: controller timed out

The values received from ACPI are (in fast mode):

  HCNT: 72
  LCNT: 160

this translates to following timings (input clock is 100MHz on Broadwell):

  tHIGH: 720 ns (spec min 600 ns)
  tLOW: 1600 ns (spec min 1300 ns)
  Bus period: 2920 ns (assuming 300 ns tf and tr)
  Bus speed: 342.5 kHz

Both tHIGH and tLOW are within the I2C specification.

The calculated values when ACPI parameters are not used are (in fast mode):

  HCNT: 87
  LCNT: 159

which translates to:

  tHIGH: 870 ns (spec min 600 ns)
  tLOW: 1590 ns (spec min 1300 ns)
  Bus period 3060 ns (assuming 300 ns tf and tr)
  Bus speed 326.8 kHz

These values are also within the I2C specification.

Since both ACPI and calculated values meet the I2C specification timing
requirements it is hard to say why the touchpad does not function properly
with the ACPI values except that the bus speed is higher in this case (but
still well below the max 400kHz).

Solve this by adding DMI quirk to the driver that disables using ACPI
parameters on this particulare machine.
Reported-by: NPavel Roskin <plroskin@gmail.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NPavel Roskin <plroskin@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

Commit 6afdb859 ("mm: do not ignore mapping_gfp_mask in page cache
allocation paths") has caught some users of hardcoded GFP_KERNEL used in
the page cache allocation paths.  This, however, wasn't complete and
there were others which went unnoticed.

Dave Chinner has reported the following deadlock for xfs on loop device:
: With the recent merge of the loop device changes, I'm now seeing
: XFS deadlock on my single CPU, 1GB RAM VM running xfs/073.
:
: The deadlocked is as follows:
:
: kloopd1: loop_queue_read_work
:       xfs_file_iter_read
:       lock XFS inode XFS_IOLOCK_SHARED (on image file)
:       page cache read (GFP_KERNEL)
:       radix tree alloc
:       memory reclaim
:       reclaim XFS inodes
:       log force to unpin inodes
:       <wait for log IO completion>
:
: xfs-cil/loop1: <does log force IO work>
:       xlog_cil_push
:       xlog_write
:       <loop issuing log writes>
:               xlog_state_get_iclog_space()
:               <blocks due to all log buffers under write io>
:               <waits for IO completion>
:
: kloopd1: loop_queue_write_work
:       xfs_file_write_iter
:       lock XFS inode XFS_IOLOCK_EXCL (on image file)
:       <wait for inode to be unlocked>
:
: i.e. the kloopd, with it's split read and write work queues, has
: introduced a dependency through memory reclaim. i.e. that writes
: need to be able to progress for reads make progress.
:
: The problem, fundamentally, is that mpage_readpages() does a
: GFP_KERNEL allocation, rather than paying attention to the inode's
: mapping gfp mask, which is set to GFP_NOFS.
:
: The didn't used to happen, because the loop device used to issue
: reads through the splice path and that does:
:
:       error = add_to_page_cache_lru(page, mapping, index,
:                       GFP_KERNEL & mapping_gfp_mask(mapping));

This has changed by commit aa4d8616 ("block: loop: switch to VFS
ITER_BVEC").

This patch changes mpage_readpage{s} to follow gfp mask set for the
mapping.  There are, however, other places which are doing basically the
same.

lustre:ll_dir_filler is doing GFP_KERNEL from the function which
apparently uses GFP_NOFS for other allocations so let's make this
consistent.

cifs:readpages_get_pages is called from cifs_readpages and
__cifs_readpages_from_fscache called from the same path obeys mapping
gfp.

ramfs_nommu_expand_for_mapping is hardcoding GFP_KERNEL as well
regardless it uses mapping_gfp_mask for the page allocation.

ext4_mpage_readpages is the called from the page cache allocation path
same as read_pages and read_cache_pages

As I've noticed in my previous post I cannot say I would be happy about
sprinkling mapping_gfp_mask all over the place and it sounds like we
should drop gfp_mask argument altogether and use it internally in
__add_to_page_cache_locked that would require all the filesystems to use
mapping gfp consistently which I am not sure is the case here.  From a
quick glance it seems that some file system use it all the time while
others are selective.
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NDave Chinner <david@fromorbit.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This covers only the simplest case - an object size sized write, but
it's still useful in tiering setups when EC is used for the base tier
as writefull op can be proxied, saving an object promotion.

Even though updating ceph_osdc_new_request() to allow writefull should
just be a matter of fixing an assert, I didn't do it because its only
user is cephfs.  All other sites were updated.

Reflects ceph.git commit 7bfb7f9025a8ee0d2305f49bf0336d2424da5b5b.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

Commit 30e2bc08 ("Revert "block: remove artifical max_hw_sectors
cap"") restored a clamp on max_sectors.  It's now 2560 sectors instead
of 1024, but it's not good enough: we set max_hw_sectors to rbd object
size because we don't want object sized I/Os to be split, and the
default object size is 4M.

So, set max_sectors to max_hw_sectors in rbd at queue init time.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

When we create a generic MSI domain, that MSI_FLAG_USE_DEF_CHIP_OPS
is set, and that any of .mask or .unmask are NULL in the irq_chip
structure, we set them to pci_msi_[un]mask_irq.

This is a bad idea for at least two reasons:
- PCI_MSI might not be selected, kernel fails to build (yes, this is
  legitimate, at least on arm64!)
- This may not be a PCI/MSI domain at all (platform MSI, for example)

Either way, this looks wrong. Move the overriding of mask/unmask to
the PCI counterpart, and panic is any of these two methods is not
set in the core code (they really should be present).
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1444760085-27857-1-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>