Commit Graph

25 Commits

Author SHA1 Message Date
Vladimir Davydov 53d85c9856 cleancache: forbid overriding cleancache_ops
Currently, cleancache_register_ops returns the previous value of
cleancache_ops to allow chaining.  However, chaining, as it is
implemented now, is extremely dangerous due to possible pool id
collisions.  Suppose, a new cleancache driver is registered after the
previous one assigned an id to a super block.  If the new driver assigns
the same id to another super block, which is perfectly possible, we will
have two different filesystems using the same id.  No matter if the new
driver implements chaining or not, we are likely to get data corruption
with such a configuration eventually.

This patch therefore disables the ability to override cleancache_ops
altogether as potentially dangerous.  If there is already cleancache
driver registered, all further calls to cleancache_register_ops will
return EBUSY.  Since no user of cleancache implements chaining, we only
need to make minor changes to the code outside the cleancache core.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:03 -07:00
Jan Beulich 144c61ad35 xen/tmem: mark xen_tmem_init() __init
As a module_init() function, this should have been this way from the
beginning.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-23 11:55:24 +00:00
Linus Torvalds 3e34131a65 Bug-fixes:
* Fix memory leak when CPU hotplugging.
 * Compile bugs with various #ifdefs
 * Fix state changes in Xen PCI front not dealing well with new toolstack.
 * Cleanups in code (use pr_*, fix 80 characters splits, etc)
 * Long standing bug in double-reporting the steal time
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Merge tag 'stable/for-linus-3.11-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen bugfixes from Konrad Rzeszutek Wilk:
 - Fix memory leak when CPU hotplugging.
 - Compile bugs with various #ifdefs
 - Fix state changes in Xen PCI front not dealing well with new
   toolstack.
 - Cleanups in code (use pr_*, fix 80 characters splits, etc)
 - Long standing bug in double-reporting the steal time

* tag 'stable/for-linus-3.11-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/time: remove blocked time accounting from xen "clockchip"
  xen: Convert printks to pr_<level>
  xen: ifdef CONFIG_HIBERNATE_CALLBACKS xen_*_suspend
  xen/pcifront: Deal with toolstack missing 'XenbusStateClosing' state.
  xen/time: Free onlined per-cpu data structure if we want to online it again.
  xen/time: Check that the per_cpu data structure has data before freeing.
  xen/time: Don't leak interrupt name when offlining.
  xen/time: Encapsulate the struct clock_event_device in another structure.
  xen/spinlock: Don't leak interrupt name when offlining.
  xen/smp: Don't leak interrupt name when offlining.
  xen/smp: Set the per-cpu IRQ number to a valid default.
  xen/smp: Introduce a common structure to contain the IRQ name and interrupt line.
  xen/smp: Coalesce the free_irq calls in one function.
  xen-pciback: fix error return code in pcistub_irq_handler_switch()
2013-07-03 13:12:42 -07:00
Joe Perches 283c0972d5 xen: Convert printks to pr_<level>
Convert printks to pr_<level> (excludes printk(KERN_DEBUG...)
to be more consistent throughout the xen subsystem.

Add pr_fmt with KBUILD_MODNAME or "xen:" KBUILD_MODNAME
Coalesce formats and add missing word spaces
Add missing newlines
Align arguments and reflow to 80 columns
Remove DRV_NAME from formats as pr_fmt adds the same content

This does change some of the prefixes of these messages
but it also does make them more consistent.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-28 11:19:58 -04:00
Konrad Rzeszutek Wilk b2c75c446a xen/tmem: Don't over-write tmem_frontswap_poolid after tmem_frontswap_init set it.
Commit 10a7a07713 ("xen: tmem: enable Xen
tmem shim to be built/loaded as a module") allows the tmem module
to be loaded any time. For this work the frontswap API had to
be able to asynchronously to call tmem_frontswap_init before
or after the swap image had been set. That was added in git
commit 905cd0e1bf
("mm: frontswap: lazy initialization to allow tmem backends to build/run as modules").

Which means we could do this (The common case):

 modprobe tmem		[so calls frontswap_register_ops, no ->init]
			 modifies tmem_frontswap_poolid = -1
 swapon /dev/xvda1	[__frontswap_init, calls -> init, tmem_frontswap_poolid is
			 < 0 so tmem hypercall done]

Or the failing one:

 swapon /dev/xvda1	[calls __frontswap_init, sets the need_init bitmap]
 modprobe tmem		[calls frontswap_register_ops, -->init calls, finds out
			tmem_frontswap_poolid is 0, does not make a hypercall.
			Later in the module_init, sets tmem_frontswap_poolid=-1]

Which meant that in the failing case we would not call the hypercall
to initialize the pool and never be able to make any frontswap
backend calls.

Moving the frontswap_register_ops after setting the tmem_frontswap_poolid
fixes it.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
2013-06-10 10:14:33 -04:00
Frederico Cadete 1d7004f059 xmem/tmem: fix 'undefined variable' build error.
In the (not so useful) kernel configuration where CONFIG_SWAP
is undefined and CONFIG_XEN_SELFBALLOONING is defined,
xen_tmem_init would use undefined variable 'static bool frontswap'.

Added #else to have #define frontswap (0) in the case where
CONFIG_FRONTSWAP is not defined.

Signed-off-by: Frederico Cadete <frederico@cadete.eu>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-28 09:54:48 -04:00
Konrad Rzeszutek Wilk 37d46e152e xen/tmem: Don't use self[ballooning|shrinking] if frontswap is off.
There is no point. We would just squeeze the guest to put more and
more pages in the swap disk without any purpose.

The only time it makes sense to use the selfballooning and shrinking
is when frontswap is being utilized.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-15 10:27:50 -04:00
Konrad Rzeszutek Wilk 2ca62b0444 xen/tmem: Remove the boot options and fold them in the tmem.X parameters.
If tmem is built-in or a module, the user has the option on
the command line to influence it by doing: tmem.<some option>
instead of having a variety of "nocleancache", and
"nofrontswap". The others: "noselfballooning" and "selfballooning";
and "noselfshrink" are in a different driver xen-selfballoon.c
and the patches:

 xen/tmem: Remove the usage of 'noselfshrink' and use 'tmem.selfshrink' bool instead.
 xen/tmem: Remove the usage of 'noselfballoon','selfballoon' and use 'tmem.selfballon' bool instead.

remove them.

Also add documentation.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-15 10:27:47 -04:00
Konrad Rzeszutek Wilk 9fd19653fa xen/tmem: s/disable_// and change the logic.
The variety of disable_[cleancache|frontswap|selfshrinking] are
making this a bit complex. Just remove the "disable_" part and
change the logic around for the "nofrontswap" and "nocleancache"
parameters.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-15 10:27:46 -04:00
Konrad Rzeszutek Wilk 23972c6399 xen/tmem: Fix compile warning.
We keep on getting:
drivers/xen/tmem.c:65:13: warning: ‘disable_frontswap_selfshrinking’ defined but not used [-Wunused-variable]

if CONFIG_FRONTSWAP=y and # CONFIG_CLEANCACHE is not set

Found by 0 day test project

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-15 10:27:45 -04:00
Konrad Rzeszutek Wilk e8f9cb034b xen/tmem: Split out the different module/boot options.
There are three options - depending on what combination of
CONFIG_FRONTSWAP, CONFIG_CLEANCACHE and CONFIG_XEN_SELFBALLOONING
is used. Lets split them out nicely out in three groups to
make it easier to clean up.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-15 10:27:44 -04:00
Konrad Rzeszutek Wilk 0cb401d44e xen/tmem: Move all of the boot and module parameters to the top of the file.
Just code movement to see the different boot or module parameters.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-15 10:27:43 -04:00
Konrad Rzeszutek Wilk a5e9cd952e xen/tmem: Cleanup. Remove the parts that say temporary.
Frontswap is upstream, no need to having this #ifdef.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-15 10:27:43 -04:00
Konrad Rzeszutek Wilk f42158fe67 zcache/tmem: Better error checking on frontswap_register_ops return value.
In the past it either used to be NULL or the "older" backend. Now we
also return -Exx error codes.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:01 -07:00
Dan Magenheimer 10a7a07713 xen: tmem: enable Xen tmem shim to be built/loaded as a module
Allow Xen tmem shim to be built/loaded as a module.  Xen self-ballooning
and frontswap-selfshrinking are now also "lazily" initialized when the
Xen tmem shim is loaded as a module, unless explicitly disabled by
module parameters.

Note runtime dependency disallows loading if cleancache/frontswap lazy
initialization patches are not present.

If built-in (not built as a module), the original mechanism of enabling
via a kernel boot parameter is retained, but this should be considered
deprecated.

Note that module unload is explicitly not yet supported.

[v1: Removed the [CLEANCACHE|FRONTSWAP]_HAS_LAZY_INIT ifdef]
[v2: Squashed the xen/tmem: Remove the subsys call patch in]
[akpm@linux-foundation.org: fix build (disable_frontswap_selfshrinking undeclared)]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:01 -07:00
Konrad Rzeszutek Wilk 833f8662af cleancache: Make cleancache_init use a pointer for the ops
Instead of using a backend_registered to determine whether a backend is
enabled.  This allows us to remove the backend_register check and just
do 'if (cleancache_ops)'

[v1: Rebase on top of b97c4b430b0a (ramster->zcache move]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:01 -07:00
Konrad Rzeszutek Wilk 1e01c968db frontswap: make frontswap_init use a pointer for the ops
This simplifies the code in the frontswap - we can get rid of the
'backend_registered' test and instead check against frontswap_ops.

[v1: Rebase on top of 703ba7fe5e (ramster->zcache move]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:00 -07:00
Konrad Rzeszutek Wilk 22230c18ab xen/tmem: Add missing %s in the printk statement.
Seems that it got lost.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-02-19 22:02:31 -05:00
Konrad Rzeszutek Wilk b8b0f559c7 xen/apic/xenbus/swiotlb/pcifront/grant/tmem: Make functions or variables static.
There is no need for those functions/variables to be visible. Make them
static and also fix the compile warnings of this sort:

drivers/xen/<some file>.c: warning: symbol '<blah>' was not declared. Should it be static?

Some of them just require including the header file that
declares the functions.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-21 14:50:03 -04:00
Konrad Rzeszutek Wilk 165c8aed5b frontswap: s/put_page/store/g s/get_page/load
Sounds so much more natural.

Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-15 11:34:08 -04:00
Linus Torvalds e22057c859 One tiny feature that accidentally got lost in the initial git pull:
* Add fast-EOI acking of interrupts (clear a bit instead of hypercall)
 And bug-fixes:
  * Fix CPU bring-up code missing a call to notify other subsystems.
  * Fix reading /sys/hypervisor even if PVonHVM drivers are not loaded.
  * In Xen ACPI processor driver: remove too verbose WARN messages, fix up
    the Kconfig dependency to be a module by default, and add dependency on
    CPU_FREQ.
  * Disable CPU frequency drivers from loading when booting under Xen
    (as we want the Xen ACPI processor to be used instead).
  * Cleanups in tmem code.
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Merge tag 'stable/for-linus-3.4-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull more xen updates from Konrad Rzeszutek Wilk:
 "One tiny feature that accidentally got lost in the initial git pull:
   * Add fast-EOI acking of interrupts (clear a bit instead of
     hypercall)
  And bug-fixes:
   * Fix CPU bring-up code missing a call to notify other subsystems.
   * Fix reading /sys/hypervisor even if PVonHVM drivers are not loaded.
   * In Xen ACPI processor driver: remove too verbose WARN messages, fix
     up the Kconfig dependency to be a module by default, and add
     dependency on CPU_FREQ.
   * Disable CPU frequency drivers from loading when booting under Xen
     (as we want the Xen ACPI processor to be used instead).
   * Cleanups in tmem code."

* tag 'stable/for-linus-3.4-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/acpi: Fix Kconfig dependency on CPU_FREQ
  xen: initialize platform-pci even if xen_emul_unplug=never
  xen/smp: Fix bringup bug in AP code.
  xen/acpi: Remove the WARN's as they just create noise.
  xen/tmem: cleanup
  xen: support pirq_eoi_map
  xen/acpi-processor: Do not depend on CPU frequency scaling drivers.
  xen/cpufreq: Disable the cpu frequency scaling drivers from loading.
  provide disable_cpufreq() function to disable the API.
2012-03-24 12:20:25 -07:00
Jan Beulich 8e6f7c23c1 xen/tmem: cleanup
Use 'bool' for boolean variables. Do proper section placement.
Eliminate an unnecessary export.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-03-20 15:34:18 -04:00
Dan Magenheimer 91c6cc9b5c mm: zcache/tmem/cleancache: s/flush/invalidate/
Complete the renaming from "flush" to "invalidate" across
both tmem frontends (cleancache and frontswap) and both tmem backends
(Xen and zcache), as required by akpm.

This change is completely cosmetic.

[v10: no change]
[v9: akpm@linux-foundation.org: change "flush" to "invalidate", part 3]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jan Beulich <JBeulich@novell.com>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Rik Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
[v11: Remove the frontswap part]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-01-23 16:06:37 -05:00
Dan Magenheimer afec6e0492 xen: prepare tmem shim to handle frontswap
Provide the shim code for frontswap for Xen tmem even if the
frontswap patchset is not present yet.  (The egg is before
the chicken.)

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Konrad Wilk <konrad.wilk@oracle.com>
2011-06-17 15:06:20 -06:00
Dan Magenheimer 5bc20fc597 xen: cleancache shim to Xen Transcendent Memory
This patch provides a shim between the kernel-internal cleancache
API (see Documentation/mm/cleancache.txt) and the Xen Transcendent
Memory ABI (see http://oss.oracle.com/projects/tmem).

Xen tmem provides "hypervisor RAM" as an ephemeral page-oriented
pseudo-RAM store for cleancache pages, shared cleancache pages,
and frontswap pages.  Tmem provides enterprise-quality concurrency,
full save/restore and live migration support, compression
and deduplication.

A presentation showing up to 8% faster performance and up to 52%
reduction in sectors read on a kernel compile workload, despite
aggressive in-kernel page reclamation ("self-ballooning") can be
found at:

http://oss.oracle.com/projects/tmem/dist/documentation/presentations/TranscendentMemoryXenSummit2010.pdf

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>
2011-05-26 10:02:21 -06:00