An XFS workload showed up a bug in the lockless pagecache patch. Basically it
would go into an "infinite" loop, although it would sometimes be able to break
out of the loop! The reason is a missing compiler barrier in the "increment
reference count unless it was zero" case of the lockless pagecache protocol in
the gang lookup functions.
This would cause the compiler to use a cached value of struct page pointer to
retry the operation with, rather than reload it. So the page might have been
removed from pagecache and freed (refcount==0) but the lookup would not correctly
notice the page is no longer in pagecache, and keep attempting to increment the
refcount and failing, until the page gets reallocated for something else. This
isn't a data corruption because the condition will be detected if the page has
been reallocated. However it can result in a lockup.
Linus points out that ACCESS_ONCE is also required in that pointer load, even
if it's absence is not causing a bug on our particular build. The most general
way to solve this is just to put an rcu_dereference in radix_tree_deref_slot.
Assembly of find_get_pages,
before:
.L220:
movq (%rbx), %rax #* ivtmp.1162, tmp82
movq (%rax), %rdi #, prephitmp.1149
.L218:
testb $1, %dil #, prephitmp.1149
jne .L217 #,
testq %rdi, %rdi # prephitmp.1149
je .L203 #,
cmpq $-1, %rdi #, prephitmp.1149
je .L217 #,
movl 8(%rdi), %esi # <variable>._count.counter, c
testl %esi, %esi # c
je .L218 #,
after:
.L212:
movq (%rbx), %rax #* ivtmp.1109, tmp81
movq (%rax), %rdi #, ret
testb $1, %dil #, ret
jne .L211 #,
testq %rdi, %rdi # ret
je .L197 #,
cmpq $-1, %rdi #, ret
je .L211 #,
movl 8(%rdi), %esi # <variable>._count.counter, c
testl %esi, %esi # c
je .L212 #,
(notice the obvious infinite loop in the first example, if page->count remains 0)
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'audit.b61' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
audit: validate comparison operations, store them in sane form
clean up audit_rule_{add,del} a bit
make sure that filterkey of task,always rules is reported
audit rules ordering, part 2
fixing audit rule ordering mess, part 1
audit_update_lsm_rules() misses the audit_inode_hash[] ones
sanitize audit_log_capset()
sanitize audit_fd_pair()
sanitize audit_mq_open()
sanitize AUDIT_MQ_SENDRECV
sanitize audit_mq_notify()
sanitize audit_mq_getsetattr()
sanitize audit_ipc_set_perm()
sanitize audit_ipc_obj()
sanitize audit_socketcall
don't reallocate buffer in every audit_sockaddr()
Add standard interfaces for alarm/update irqs enabling. Drivers are no
more required to implement equivalent ioctl code as rtc-dev will provide
it.
UIE emulation should now be handled correctly and will work even for those
RTC drivers who cannot be configured to do both UIE and AIE.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened. They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim. This bug could
cause filesystem deadlocks.
The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called. It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock. The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.
Add a new flag for write_begin, AOP_FLAG_NOFS. Filesystems can now act on
this flag in their write_begin function. Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).
This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg. ocfs2_alloc_write_ctxt, for a
random example).
[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org> [2.6.28.x]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
untouched to the grab_cache_page_write_begin() function. That
just simplifies everybody, and may even allow future expansion of the
logic. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As suggested by Andreas Dilger, introduce a bgl_lock_ptr() helper in
<linux/blockgroup_lock.h> and add separate sb_bgl_lock() helpers to
filesystem specific header files to break the hidden dependency to
struct ext[234]_sb_info.
Also, while at it, convert the macros to static inlines to try make up
for all the times I broke Andrew Morton's tree.
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Include header files as used/needed:
In file included from drivers/leds/leds-dac124s085.c:16:
include/linux/spi/spi.h:66: error: field 'dev' has incomplete type
include/linux/spi/spi.h: In function 'to_spi_device':
include/linux/spi/spi.h💯 warning: type defaults to 'int' in declaration of '__mptr'
...
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't store the field->op in the messy (and very inconvenient for e.g.
audit_comparator()) form; translate to dense set of values and do full
validation of userland-submitted value while we are at it.
->audit_init_rule() and ->audit_match_rule() get new values now; in-tree
instances updated.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix the actual rule listing; add per-type lists _not_ used for matching,
with all exit,... sitting on one such list. Simplifies "do something
for all rules" logics, while we are at it...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Problem: ordering between the rules on exit chain is currently lost;
all watch and inode rules are listed after everything else _and_
exit,never on one kind doesn't stop exit,always on another from
being matched.
Solution: assign priorities to rules, keep track of the current
highest-priority matching rule and its result (always/never).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't bother with allocations
* don't do double copy_from_user()
* don't duplicate parts of check for audit_dummy_context()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* logging the original value of *msg_prio in mq_timedreceive(2)
is insane - the argument is write-only (i.e. syscall always
ignores the original value and only overwrites it).
* merge __audit_mq_timed{send,receive}
* don't do copy_from_user() twice
* don't mess with allocations in auditsc part
* ... and don't bother checking !audit_enabled and !context in there -
we'd already checked for audit_dummy_context().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't copy_from_user() twice
* don't bother with allocations
* don't duplicate parts of audit_dummy_context()
* make it return void
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'cpus4096-for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (77 commits)
x86: setup_per_cpu_areas() cleanup
cpumask: fix compile error when CONFIG_NR_CPUS is not defined
cpumask: use alloc_cpumask_var_node where appropriate
cpumask: convert shared_cpu_map in acpi_processor* structs to cpumask_var_t
x86: use cpumask_var_t in acpi/boot.c
x86: cleanup some remaining usages of NR_CPUS where s/b nr_cpu_ids
sched: put back some stack hog changes that were undone in kernel/sched.c
x86: enable cpus display of kernel_max and offlined cpus
ia64: cpumask fix for is_affinity_mask_valid()
cpumask: convert RCU implementations, fix
xtensa: define __fls
mn10300: define __fls
m32r: define __fls
h8300: define __fls
frv: define __fls
cris: define __fls
cpumask: CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
cpumask: zero extra bits in alloc_cpumask_var_node
cpumask: replace for_each_cpu_mask_nr with for_each_cpu in kernel/time/
cpumask: convert mm/
...
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (34 commits)
V4L/DVB (10173): Missing v4l2_prio_close in radio_release
V4L/DVB (10172): add DVB_DEVICE_TYPE= to uevent
V4L/DVB (10171): Use usb_set_intfdata
V4L/DVB (10170): tuner-simple: prevent possible OOPS caused by divide by zero error
V4L/DVB (10168): sms1xxx: fix inverted gpio for lna control on tiger r2
V4L/DVB (10167): sms1xxx: add support for inverted gpio
V4L/DVB (10166): dvb frontend: stop using non-C99 compliant comments
V4L/DVB (10165): Add FE_CAN_2G_MODULATION flag to frontends that support DVB-S2
V4L/DVB (10164): Add missing S2 caps flag to S2API
V4L/DVB (10163): em28xx: allocate adev together with struct em28xx dev
V4L/DVB (10162): tuner-simple: Fix tuner type set message
V4L/DVB (10161): saa7134: fix autodetection for AVer TV GO 007 FM Plus
V4L/DVB (10160): em28xx: update chip id for em2710
V4L/DVB (10157): Add USB ID for the Sil4701 radio from DealExtreme
V4L/DVB (10156): saa7134: Add support for Avermedia AVer TV GO 007 FM Plus
V4L/DVB (10155): Add TEA5764 radio driver
V4L/DVB (10154): saa7134: fix a merge conflict on Behold H6 board
V4L/DVB (10153): Add the Beholder H6 card to DVB-T part of sources.
V4L/DVB (10152): Change configuration of the Beholder H6 card
V4L/DVB (10151): Fix I2C bridge error in zl10353
...
those two functions only used in that C file
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
mmc: warn about voltage mismatches
mmc_spi: Add support for OpenFirmware bindings
pxamci: fix dma_unmap_sg length
mmc_block: ensure all sectors that do not have errors are read
drivers/mmc: Move a dereference below a NULL test
sdhci: handle built-in sdhci with modular leds class
mmc: balanc pci_iomap with pci_iounmap
mmc_block: print better error messages
mmc: Add mmc_vddrange_to_ocrmask() helper function
ricoh_mmc: Handle newer models of Ricoh controllers
mmc: Add 8-bit bus width support
sdhci: activate led support also when module
mmc: trivial annotation of 'blocks'
pci: use pci_ioremap_bar() in drivers/mmc
sdricoh_cs: Add support for Bay Controller devices
mmc: at91_mci: reorder timer setup and mmc_add_host() call
This patch introduces the API to abstract the exported VT-d functions
for KVM into a generic API. This way the AMD IOMMU implementation can
plug into this API later.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
In kvm_iommu_unmap_memslots(), assigned_dev_head is already empty.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Support device deassignment, it can be used in device hotplug.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
intel iommu APIs are updated, use the new APIs.
In addition, change kvm_iommu_map_guest() to just create the domain, let kvm_iommu_assign_device() assign device.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
"SAGAW" capability may be different across iommus. Use a default agaw, but if default agaw is not supported in some iommus, choose a less supported agaw.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This is only used in dmar.c and intel-iommu.h, so dma_remapping.h
seems like the appropriate place for it.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
We keep the struct root_entry forward declaration for the
pointer in struct intel_iommu.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
init_dmars() is not used outside of drivers/pci/intel-iommu.c
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The seg, saved_msg and sysdev fields appear to be unused since
before the code was first merged.
linux/msi.h is not needed in linux/intel-iommu.h anymore since
there is no longer a reference to struct msi_msg. The MSI code
in drivers/pci/intel-iommu.c still has linux/msi.h included
via linux/dmar.h.
linux/sysdev.h isn't needed because there is no reference to
struct sys_device.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
GCC 3.0 and 3.1 are too old to build a working kernel.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ This check got dropped as obsolete when I simplified the gcc header
inclusion mess in f153b82121, but Willy
Tarreau reports actually having those old versions still.. -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits)
x86: export vector_used_by_percpu_irq
x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and()
sched: nominate preferred wakeup cpu, fix
x86: fix lguest used_vectors breakage, -v2
x86: fix warning in arch/x86/kernel/io_apic.c
sched: fix warning in kernel/sched.c
sched: move test_sd_parent() to an SMP section of sched.h
sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
sched: activate active load balancing in new idle cpus
sched: bias task wakeups to preferred semi-idle packages
sched: nominate preferred wakeup cpu
sched: favour lower logical cpu number for sched_mc balance
sched: framework for sched_mc/smt_power_savings=N
sched: convert BALANCE_FOR_xx_POWER to inline functions
x86: use possible_cpus=NUM to extend the possible cpus allowed
x86: fix cpu_mask_to_apicid_and to include cpu_online_mask
x86: update io_apic.c to the new cpumask code
x86: Introduce topology_core_cpumask()/topology_thread_cpumask()
x86: xen: use smp_call_function_many()
x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c
...
Fixed up trivial conflict in kernel/time/tick-sched.c manually
* 'kvm-updates/2.6.29' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (140 commits)
KVM: MMU: handle large host sptes on invlpg/resync
KVM: Add locking to virtual i8259 interrupt controller
KVM: MMU: Don't treat a global pte as such if cr4.pge is cleared
MAINTAINERS: Maintainership changes for kvm/ia64
KVM: ia64: Fix kvm_arch_vcpu_ioctl_[gs]et_regs()
KVM: x86: Rework user space NMI injection as KVM_CAP_USER_NMI
KVM: VMX: Fix pending NMI-vs.-IRQ race for user space irqchip
KVM: fix handling of ACK from shared guest IRQ
KVM: MMU: check for present pdptr shadow page in walk_shadow
KVM: Consolidate userspace memory capability reporting into common code
KVM: Advertise the bug in memory region destruction as fixed
KVM: use cpumask_var_t for cpus_hardware_enabled
KVM: use modern cpumask primitives, no cpumask_t on stack
KVM: Extract core of kvm_flush_remote_tlbs/kvm_reload_remote_mmus
KVM: set owner of cpu and vm file operations
anon_inodes: use fops->owner for module refcount
x86: KVM guest: kvm_get_tsc_khz: return khz, not lpj
KVM: MMU: prepopulate the shadow on invlpg
KVM: MMU: skip global pgtables on sync due to cr3 switch
KVM: MMU: collapse remote TLB flushes on root sync
...
