Robert Hancock [Sun, 13 Sep 2009 05:54:47 +0000 (23:54 -0600)]
pata_amd: do not filter out valid modes in nv_mode_filter
On a Compaq Presario V3000 laptop (NVIDIA MCP51 chipset), pata_amd selects
PIO0 mode for the PATA DVD-RAM drive instead of MWDMA2 which it supports:
ata4.00: ATAPI: HL-DT-ST DVDRAM GSA-4084N, KQ09, max MWDMA2
ata4: nv_mode_filter: 0x39f&0x7001->0x1, BIOS=0x0 (0x0) ACPI=0x7001 (60:600:0x11)
ata4.00: configured for PIO0
For some reason, the BIOS-set UDMA configuration returns 0 and the ACPI _GTM
reports that UDMA2 and PIO0 are enabled. This causes nv_mode_filter to end up
allowing only PIO0 and UDMA0-2. Since the drive doesn't support UDMA we end up
using PIO0.
Since the controllers should always support PIO4, MWDMA2 and UDMA2 regardless
of what cable type is used, let's make sure we don't filter out these modes
regardless of what wacky settings the BIOS is using.
Signed-off-by: Robert Hancock <hancockrwd@gmail.com> Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
sata_promise's reset code has deviated quite a bit from
the Promise reference driver's, and it has been observed
to fail to recover from errors in some cases.
This patch thus updates the reset code to more closely
match the reference driver:
- soft reset (pdc_reset_port):
* wait for ATA engine to not be in packet command mode
(2nd gen only)
* write reset bit in PDC_CTLSTAT before the first read
in the loop
* for 2nd gen SATA follow up with FPDMA reset and clearing
error status registers
- hard reset (pdc_sata_hardreset):
* wait for ATA engine to not be in packet command mode
(2nd gen only)
* reset ATA engine via the PCI control register
* Tejun's change to use non-waiting hardreset + follow-up SRST
I'm not changing the hotplug mask bits since they are taken care
of by sata_promise's ->freeze() and ->thaw() operations. And I'm
not writing the PMP port # because that's always zero (for now).
Tested here on various controllers. In particular, one disk
which used to timeout and fail to recover from certain hdparm
and smartmonctl commands now works nicely.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
1st generation Promise SATA chips are prone to generating spurious
hotplug events which can disrupt normal operation. This has been
observed on 20376 and 20378 chips. This patch thus disables hotplug
support on 1st gen chips while leaving it enabled for 2nd gen chips.
The pdc_sata_hotplug_offset() function becomes redundant so it is
removed.
Tested on 1st gen 20376 and 20378 mainboard chips and on a 2nd gen
SATA300 PCI card.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Kurt Roeckx <kurt@roeckx.be> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
libata: fix spurious WARN_ON_ONCE() on port freeze
Commit 54c38444fad6a99b4b19512f8f0055d69115e69e makes libata abort qcs
after the port is frozen. This is necessary to guarantee that TF
registers are accessed after the DMA engine is shutdown after an
error. However, this triggers WARN_ON_ONCE() check in
ata_qc_complete() spuriously. Move WARN_ON_ONCE() downwards such that
failing commands while frozen doesn't trigger it.
Commit a5bfc4714b3f01365aef89a92673f2ceb1ccf246 dropped explicit
pci_intx() manipulation from ahci because it seemed unnecessary and
ahci doesn't seem to be the right place to be tweaking it if it were.
This was largely okay but there are exceptions. There was one on an
embedded platform which was fixed via firmware and now bko#14124
reports it on a HP DL320.
http://bugzilla.kernel.org/show_bug.cgi?id=14124
I still think this isn't something libata drivers should be caring
about (the only ones which are calling pci_intx() explicitly are
libata ones and one other driver) but for now reverting the change
seems to be the right thing to do.
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Thomas Jarosch <thomas.jarosch@intra2net.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
amd64_edac: check NB MCE bank enable on the current node properly
amd64_edac: Rewrite unganged mode code of f10_early_channel_count
amd64_edac: cleanup amd64_check_ecc_enabled
x86, EDAC: Provide function to return NodeId of a CPU
amd64_edac: build driver only on AMD hardware
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: (53 commits)
m68knommu: Make PAGE_SIZE available to assembly files.
m68knommu: fix ColdFire definition of CLOCK_TICK_RATE
m68knommu: set multi-function pins for ethernet when enabled
m68knommu: remove special interrupt handling code for ne2k support
m68knommu: relax IO_SPACE_LIMIT setting
m68knommu: remove ColdFire direct interrupt register access
m68knommu: create a speciailized ColdFire 5272 interrupt controller
m68knommu: add support for second interrupt controller of ColdFire 5249
m68knommu: clean up old ColdFire timer irq setup
m68knommu: map ColdFire interrupts to correct masking bits
m68knommu: clean up ColdFire 532x CPU timer setup
m68knommu: simplify ColdFire "timers" clock initialization
m68knommu: support code to mask external interrupts on old ColdFire CPU's
m68knommu: merge old ColdFire interrupt controller masking macros
m68knommu: remove duplicate ColdFire mcf_autovector() code
m68knommu: move ColdFire INTC definitions to new include file
m68knommu: mask off all interrupts in ColdFire intc-simr controller
m68knommu: remove timer device interrupt setup for ColdFire 532x
m68knommu: remove interrupt masking from ColdFire pit timer
m68knommu: remove unecessary interrupt level setting in ColdFire 520x setup
...
Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
hwmon: (lm85) Don't bind to Winbond/Nuvoton WPCD377I
hwmon: (pcf8591) Documentation clean-ups
hwmon: Clearly mark ACPI drivers as such
hwmon: Use resource_size
hwmon: Include <linux/io.h> instead of <asm/io.h>
hwmon: (tmp421) Add documentation
hwmon: Add driver for Texas Instruments TMP421/422/423 sensor chips
hwmon-vid: Ignore 6th VID pin of AMD family 0Fh processors
hwmon: (asus_atk0110) Add maintainer information
hwmon: (abituguru3) Support multiple DMI strings per chip ID
Yi Li [Tue, 15 Sep 2009 09:24:31 +0000 (09:24 +0000)]
Blackfin: update ftrace for latest toolchain
The mcount support that was finally added to the Blackfin gcc port isn't
exactly the same as what ftrace was developed against. Now that the final
gcc version is in place, update the ftrace code to match.
While updating this, fix the swapped arguments to the tracer (signature is
(ip, parent_ip) while we were passing (parent_ip, ip)).
Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Mike Frysinger [Mon, 14 Sep 2009 21:22:06 +0000 (21:22 +0000)]
Blackfin: fix elf_fpregset_t definition
The elf_fpregset_t type relied on an empty struct in the asm/user.h, but
the transition to asm-generic/user.h dropped that empty struct. Rather
than restore this useless struct, define the only user (elf_fpregset_t)
as an empty struct itself. This fixes building when ELF dump support is
enabled.
Mike Frysinger [Mon, 14 Sep 2009 19:42:26 +0000 (19:42 +0000)]
Blackfin: unify cache init functions
The CPLB implementations (mpu/nompu) had exact copies of the cacheinit
code. Even the i/d cache functions are largely the same. So unify them
both in the common kernel cache code.
Commit 71e308a239c updated ftrace_push_return_trace() prototype but didn't
update the Blackfin ftrace code, so things broke. Since we don't support
the new stuff yet, call it with stub values.
Sonic Zhang [Mon, 7 Sep 2009 03:20:48 +0000 (03:20 +0000)]
Blackfin: increase default async timings for parallel flashes
The default async timings are a little too fast for the parallel flash
that is attached by default to the async banks. So slow things down a bit
so accessing the hardware is stable.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Make sure our interrupt entry code with exact hardware errors handles
anomaly 05000283 (infinite stall in system MMR kill) so we don't stall
while under load.
Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Yi Li [Thu, 20 Aug 2009 04:17:47 +0000 (04:17 +0000)]
Blackfin: use raw_smp_processor_id() in exception code
When preempt debugging is enabled, smp_processor_id() may utilize the
"current" structure. This may not be safe to access under all exceptions
due to it being in dynamically allocated memory. So in exception code,
make sure we use raw_smp_processor_id() instead to get at the real value
directly.
Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Mike Frysinger [Mon, 17 Aug 2009 19:05:07 +0000 (19:05 +0000)]
Blackfin: optimize fixed code handling for the most common case
The majority of the time we are returning to user space, it is not in the
fixed atomic code region. So rather than branch to a function where we
check the PC and return, do the check inline and branch only when needed.
Also, tweak some of the fixed code handling based on assumptions we are
aware of but cannot be expressed in C.
Yi Li [Fri, 7 Aug 2009 01:20:58 +0000 (01:20 +0000)]
Blackfin: cleanup sync handling when enabling/disabling cplbs
The handling of updating the [DI]MEM_CONTROL MMRs does not follow proper
sync procedures as laid out in the Blackfin programming manual. So rather
than audit/fix every call location, create helper functions that do the
right things in order to safely update these MMRs. Then convert all call
sites to use these new helper functions.
While we're fixing the code, drop the workaround for anomaly 05000125 as
that anomaly applies to old versions of silicon that we do not support.
Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
I think we have to use the physical dimensions [mm] of the display for
.width and .heigth in struct bfin_bf54xfb_mach_info bf54x_lq043_data which
are copied to fbinfo->var.height/.width in bf54x-lq043fb.c.
linux/fb.h describes this values as 'height/weight of picture in mm'
Otherwise QT calcs the wrong dpi value and the displayed fonts are very
small.
Signed-off-by: Stefan Pledl <stefan.pledl@mesutronic.de> Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Barry Song [Thu, 23 Jul 2009 04:20:48 +0000 (04:20 +0000)]
Blackfin: bf537-stamp: drop ATA interrupt probe workaround
The interrupt probe workaround doesn't work without hacks to common code,
and the add-on card only needs a simple resistor to fix the problem, so
drop the board-specific hack.
Signed-off-by: Barry Song <barry.song@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Graf Yang [Wed, 22 Jul 2009 11:56:24 +0000 (11:56 +0000)]
Blackfin: improve double fault debug handling
Since the hardware only provides reporting for the last exception handled,
and the values are valid only when executing the exception handler, we
need to save the context for reporting at a later point. While we do this
for one exception, it doesn't work properly when handling a second one as
the original exception is clobbered by the double fault. So when double
fault debugging is enabled, create a dedicated shadow of these values and
save/restore out of there. Now the crash report properly displays the
first exception as well as the second one.
Signed-off-by: Graf Yang <graf.yang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Graf Yang [Tue, 21 Jul 2009 02:26:57 +0000 (02:26 +0000)]
Blackfin: fix MPU handling of invalid memory accesses
The protect_page() function was incorrectly setting up the hardware tables
based on possible access capabilities rather than the actual requested
values. This means we would grant more access to mmap-ed pages than we
should have. Once we fix this, we need to tweak the signal generated by
such accesses to aline ourselves with other ports. This allows the LTP
mmap0{5,6,7} cases to run properly.
Signed-off-by: Graf Yang <graf.yang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Sonic Zhang [Thu, 16 Jul 2009 10:36:35 +0000 (10:36 +0000)]
Blackfin: do not try displaying the end of the stack
The end of the stack may not be valid (and that could be OK), so do not
attempt to parse it. If we do, we might use a bad pointer in kernel space
which makes things panic().
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Stefan Pledl [Sat, 11 Jul 2009 11:50:42 +0000 (13:50 +0200)]
Blackfin: fix BF548 UART0 DMA IRQ translation
The initial BF54x port included some defines to keep code simple across
different processors, but it just ended up causing the UART0 DMA IRQs to
be set to the UART1 channels.
Signed-off-by: Stefan Pledl <stefan.pledl@mesutronic.de> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Robin Getz [Tue, 7 Jul 2009 20:17:09 +0000 (20:17 +0000)]
Blackfin: catch hardware errors earlier during booting
Allow hardware errors to be caught during early portions of booting, and
leave something in the shadow console that people can use to debug their
system with (to be printed out by the bootloader on next reset).
This enables the hardare error interrupts in head.S, allowing us to find
hardware errors when they happen (well, as much as you can with a hardware
error) and prints out the trace if it is enabled. This will catch errors
(like booting the wrong image on a 533) which previously resulted in a
infinite loop/hang, as well as random hardware errors before before
setup_arch().
To disable this debug only feature - turn off EARLY_PRINTK.
Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Robin Getz [Mon, 6 Jul 2009 14:53:19 +0000 (14:53 +0000)]
Blackfin: add an early shadow console
Add a memory based shadow console to keep a copy of the printk buffer in a
location which can be found externally. This allows bootloaders to locate
and utilize the log buffer in case of silent (early/resume/etc...) crashes.
Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Mike Frysinger [Fri, 3 Jul 2009 00:17:45 +0000 (00:17 +0000)]
Blackfin: add support for common FDPIC ptrace requests
The FDPIC arches support a standard set of ptrace requests so rather than
define our own custom API, hook up those requests for common code to
leverage.
Mike Frysinger [Wed, 1 Jul 2009 15:42:13 +0000 (15:42 +0000)]
Blackfin: push SRAM locks down into related ifdefs
Rather than defining the locks and initializing them all the time, only do
so when we actually need them (i.e. the SRAM regions exist). This avoids
dead data and code bloat during runtime.
Mike Frysinger [Fri, 26 Jun 2009 00:49:51 +0000 (00:49 +0000)]
Blackfin: fix module reloc handling for all memory regions
The current module relocation code has spotty handling wrt different
memory regions (like L1 instruction). Rather than try to fix each
little spot, use the new common memory functions to greatly simplify
everything and make sure it is always correct.
Mike Frysinger [Fri, 26 Jun 2009 00:48:33 +0000 (00:48 +0000)]
Blackfin: cleanup module section checking
The current module section handling code has a lot of verbose statements
copied and pasted throughout which makes it pretty hard to digest at a
glance. By unifying all of these up front, it is a lot easier to quickly
get an idea of what is actually going on.
All kernel modules are required to be built with -mlong-calls and thus
should not generate any of these relocations. If they do, it means the
module has not been compiled properly, so rather than trying to handle
them (and running into random run time errors) just error out on module
load to force the module to be compiled correctly.
Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Mike Frysinger [Thu, 25 Jun 2009 00:02:58 +0000 (20:02 -0400)]
Blackfin: convert ptrace to new memory functions
Now that we have a Blackfin memory function to figure out how to properly
access the different regions, drop the custom memory range checks in our
ptrace code and use that. It makes the code nicer and fixes bugs where
the ptrace logic wasn't handling all the different regions.
Philippe Gerum [Mon, 22 Jun 2009 16:23:48 +0000 (18:23 +0200)]
Blackfin: use generic name for EVT14 handler
The purpose of the EVT14 handler may depend on whether CONFIG_IPIPE is
enabled, albeit its implementation can be the same in both cases. When
the interrupt pipeline is enabled, EVT14 can be used to raise the core
priority level for the running code; when CONFIG_IPIPE is off, EVT14
can be used to lower this level before running softirq handlers.
Rename evt14_softirq to evt_evt14 to pick an identifier that fits
both, which allows to reuse the same vector setup code as well.
Signed-off-by: Philippe Gerum <rpm@xenomai.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Philippe Gerum [Mon, 22 Jun 2009 16:23:32 +0000 (18:23 +0200)]
Blackfin: allow high priority domains to preempt schedule_tail()
ret_from_fork is always entered with hw interrupts off, which prevents
real-time domains to preempt the Linux kernel during part of the
initial context switch to the new task, which could in turn raise the
worst-case latency figures.
To avoid this, stall the root domain stage in the interrupt pipeline
to keep the scheduling tail code free from Linux-handled IRQs, then
enable hardware interrupts again.
Signed-off-by: Philippe Gerum <rpm@xenomai.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Philippe Gerum [Mon, 22 Jun 2009 16:22:48 +0000 (18:22 +0200)]
Blackfin: fix misnomer of some I-pipe helpers
__ipipe_{stall, unstall}_root_raw() identifiers may leave the reader
under the impression that only the virtual state is affected by these
operations, which is wrong. Pick names following the convention used
throughout the interrupt pipeline code.
Signed-off-by: Philippe Gerum <rpm@xenomai.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Robin Getz [Mon, 22 Jun 2009 02:02:16 +0000 (02:02 +0000)]
Blackfin: make EVT3->EVT5 lowering more robust wrt IPEND[4]
We handle many exceptions at EVT5 (hardware error level) so that we can
catch exceptions in our exception handling code. Today - if the global
interrupt enable bit (IPEND[4]) is set (interrupts disabled) our trap
handling code goes into a infinite loop, since we need interrupts to be
on to defer things to EVT5.
Normal kernel code should not trigger this for any reason as IPEND[4] gets
cleared early (when doing an interrupt context save) and the kernel stack
there should be sane (or something much worse is happening in the system).
But there have been a few times where this has happened, so this change
makes sure we dump a proper crash message even when things have gone south.
Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The "cleanup console_print()" patch in commit 353f6dd2dec992ddd34620a94b051b0f76227379 introduced an "extern"
declaration into an assembly language file. Remove it.
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
debugfs: Modify default debugfs directory for debugging pktcdvd.
debugfs: Modified default dir of debugfs for debugging UHCI.
debugfs: Change debugfs directory of IWMC3200
debugfs: Change debuhgfs directory of trace-events-sample.h
debugfs: Fix mount directory of debugfs by default in events.txt
hpilo: add poll f_op
hpilo: add interrupt handler
hpilo: staging for interrupt handling
driver core: platform_device_add_data(): use kmemdup()
Driver core: Add support for compatibility classes
uio: add generic driver for PCI 2.3 devices
driver-core: move dma-coherent.c from kernel to driver/base
mem_class: fix bug
mem_class: use minor as index instead of searching the array
driver model: constify attribute groups
UIO: remove 'default n' from Kconfig
Driver core: Add accessor for device platform data
Driver core: move dev_get/set_drvdata to drivers/base/dd.c
Driver core: add new device to bus's list before probing
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pcmcia-2.6:
pcmcia: document return value of pcmcia_loop_config
pcmcia: dtl1_cs: fix pcmcia_loop_config logic
pcmcia: drop non-existant includes
pcmcia: disable prefetch/burst for OZ6933
pcmcia: fix incorrect argument order to list_add_tail()
pcmcia: drivers/pcmcia/pcmcia_resource.c: Remove unnecessary semicolons
pcmcia: Use phys_addr_t for physical addresses
pcmcia: drivers/pcmcia: Make static
Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (75 commits)
PCI hotplug: clean up acpi_run_hpp()
PCI hotplug: acpiphp: use generic pci_configure_slot()
PCI hotplug: shpchp: use generic pci_configure_slot()
PCI hotplug: pciehp: use generic pci_configure_slot()
PCI hotplug: add pci_configure_slot()
PCI hotplug: clean up acpi_get_hp_params_from_firmware() interface
PCI hotplug: acpiphp: don't cache hotplug_params in acpiphp_bridge
PCI hotplug: acpiphp: remove superfluous _HPP/_HPX evaluation
PCI: Clear saved_state after the state has been restored
PCI PM: Return error codes from pci_pm_resume()
PCI: use dev_printk in quirk messages
PCI / PCIe portdrv: Fix pcie_portdrv_slot_reset()
PCI Hotplug: convert acpi_pci_detect_ejectable() to take an acpi_handle
PCI Hotplug: acpiphp: find bridges the easy way
PCI: pcie portdrv: remove unused variable
PCI / ACPI PM: Propagate wake-up enable for devices w/o ACPI support
ACPI PM: Replace wakeup.prepared with reference counter
PCI PM: Introduce device flag wakeup_prepared
PCI / ACPI PM: Rework some debug messages
PCI PM: Simplify PCI wake-up code
...
Fixed up conflict in arch/powerpc/kernel/pci_64.c due to OF device tree
scanning having been moved and merged for the 32- and 64-bit cases. The
'needs_freset' initialization added in 6e19314cc ("PCI/powerpc: support
PCIe fundamental reset") is now in arch/powerpc/kernel/pci_of_scan.c.
Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-block
* 'writeback' of git://git.kernel.dk/linux-2.6-block:
writeback: fix possible bdi writeback refcounting problem
writeback: Fix bdi use after free in wb_work_complete()
writeback: improve scalability of bdi writeback work queues
writeback: remove smp_mb(), it's not needed with list_add_tail_rcu()
writeback: use schedule_timeout_interruptible()
writeback: add comments to bdi_work structure
writeback: splice dirty inode entries to default bdi on bdi_destroy()
writeback: separate starting of sync vs opportunistic writeback
writeback: inline allocation failure handling in bdi_alloc_queue_work()
writeback: use RCU to protect bdi_list
writeback: only use bdi_writeback_all() for WB_SYNC_NONE writeout
fs: Assign bdi in super_block
writeback: make wb_writeback() take an argument structure
writeback: merely wakeup flusher thread if work allocation fails for WB_SYNC_NONE
writeback: get rid of wbc->for_writepages
fs: remove bdev->bd_inode_backing_dev_info
Nick Piggin [Tue, 15 Sep 2009 19:37:55 +0000 (21:37 +0200)]
writeback: fix possible bdi writeback refcounting problem
wb_clear_pending AFAIKS should not be called after the item has been
put on the list, except by the worker threads. It could lead to the
situation where the refcount is decremented below 0 and cause lots of
problems.
Presumably the !wb_has_dirty_io case is not a common one, so it can
be discovered when the thread wakes up to check?
Also add a comment in bdi_work_clear.
Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Nick Piggin [Tue, 15 Sep 2009 19:34:51 +0000 (21:34 +0200)]
writeback: Fix bdi use after free in wb_work_complete()
By the time bdi_work_on_stack gets evaluated again in bdi_work_free, it
can already have been deallocated and used for something else in the
!on stack case, giving a false positive in this test and causing
corruption.
Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Nick Piggin [Tue, 15 Sep 2009 19:34:12 +0000 (21:34 +0200)]
writeback: improve scalability of bdi writeback work queues
If you're going to do an atomic RMW on each list entry, there's not much
point in all the RCU complexities of the list walking. This is only going
to help the multi-thread case I guess, but it doesn't hurt to do now.
Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
writeback: splice dirty inode entries to default bdi on bdi_destroy()
We cannot safely ensure that the inodes are all gone at this point
in time, and we must not destroy this bdi with inodes having off it.
So just splice our entries to the default bdi since that one will
always persist.