kybaaz/linux-xiaomi-chiron
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
linux-xiaomi-chiron/drivers
History
Anssi Hannula 40aa978ecc dm cache: fix race causing dirty blocks to be marked as clean 
When a writeback or a promotion of a block is completed, the cell of
that block is removed from the prison, the block is marked as clean, and
the clear_dirty() callback of the cache policy is called.

Unfortunately, performing those actions in this order allows an incoming
new write bio for that block to come in before clearing the dirty status
is completed and therefore possibly causing one of these two scenarios:

Scenario A:

Thread 1                      Thread 2
cell_defer()                  .
- cell removed from prison    .
- detained bios queued        .
.                             incoming write bio
.                             remapped to cache
.                             set_dirty() called,
.                               but block already dirty
.                               => it does nothing
clear_dirty()                 .
- block marked clean          .
- policy clear_dirty() called .

Result: Block is marked clean even though it is actually dirty. No
writeback will occur.

Scenario B:

Thread 1                      Thread 2
cell_defer()                  .
- cell removed from prison    .
- detained bios queued        .
clear_dirty()                 .
- block marked clean          .
.                             incoming write bio
.                             remapped to cache
.                             set_dirty() called
.                             - block marked dirty
.                             - policy set_dirty() called
- policy clear_dirty() called .

Result: Block is properly marked as dirty, but policy thinks it is clean
and therefore never asks us to writeback it.
This case is visible in "dmsetup status" dirty block count (which
normally decreases to 0 on a quiet device).

Fix these issues by calling clear_dirty() before calling cell_defer().
Incoming bios for that block will then be detained in the cell and
released only after clear_dirty() has completed, so the race will not
occur.

Found by inspecting the code after noticing spurious dirty counts
(scenario B).

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-09-10 11:20:47 -04:00
..
accessibility
acpi More ACPI and power management updates for 3.17-rc1 2014-08-14 18:13:46 -06:00
amba
ata libata: widen Crucial M550 blacklist matching 2014-08-18 17:40:09 -04:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-08-13 18:27:40 -06:00
auxdisplay
base Merge branch 'akpm' (patchbomb from Andrew Morton) 2014-08-06 21:14:42 -07:00
bcma bcma: use NS prefix for names of Northstar specific cores 2014-07-31 13:45:32 -04:00
block PCI changes for the v3.17 merge window (part 2): 2014-08-14 18:10:33 -06:00
bluetooth Bluetooth: Fix crash in the Marvell driver initialization codepath 2014-07-31 01:07:28 +02:00
bus bus: arm-ccn: Fix warning message 2014-08-24 11:28:30 -07:00
cdrom
char virtio: rng: add derating factor for use by hwrng core 2014-08-15 10:26:01 +05:30
clk ARM: SoC platform changes for 3.17 2014-08-08 11:14:29 -07:00
clocksource ARM: SoC platform changes for 3.17 2014-08-08 11:14:29 -07:00
connector connector: Use ktime_get_ns() 2014-07-23 10:18:07 -07:00
cpufreq More ACPI and power management updates for 3.17-rc1 2014-08-14 18:13:46 -06:00
cpuidle More ACPI and power management updates for 3.17-rc1 2014-08-14 18:13:46 -06:00
crypto PCI changes for the v3.17 merge window (part 2): 2014-08-14 18:10:33 -06:00
dca
devfreq PM / OPP: Remove ARCH_HAS_OPP 2014-07-23 00:51:30 +02:00
dio
dma Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2014-08-11 07:14:01 -07:00
dma-buf
edac Merge branch 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac 2014-08-15 17:56:45 -06:00
eisa
extcon extcon: sm5502: Change internal hardware switch according to cable type 2014-07-23 10:22:35 +09:00
firewire Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-08-06 09:38:14 -07:00
firmware firmware: Do not use WARN_ON(!spin_is_locked()) 2014-08-22 08:45:40 +01:00
fmc
gpio gpio-lynxpoint: enable input sensing in resume 2014-08-21 07:44:57 -05:00
gpu drm/radeon: add new KV pci id 2014-08-22 10:47:58 -04:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2014-08-21 14:25:20 -07:00
hsi HSI changes for the v3.17 series 2014-08-06 20:06:14 -07:00
hv Char / Misc driver patches for 3.17-rc1 2014-08-04 17:32:24 -07:00
hwmon Several bug fixes in various drivers, plus a minor cleanup 2014-08-14 09:55:13 -06:00
hwspinlock hwspinlock: enable OMAP build for AM33xx, AM43xx & DRA7xx 2014-07-29 11:46:28 +03:00
i2c i2c: i801: Add PCI ID for Intel Braswell 2014-08-19 10:19:47 -05:00
ide ide: use module_platform_driver() 2014-08-05 21:16:46 -07:00
idle intel_idle: Broadwell support 2014-08-15 17:06:40 -04:00
iio Staging driver patches for 3.17-rc1 2014-08-04 18:36:12 -07:00
infiniband PCI changes for the v3.17 merge window (part 2): 2014-08-14 18:10:33 -06:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2014-08-15 18:16:28 -06:00
iommu iommu/core: Check for the right function pointer in iommu_map() 2014-08-19 00:19:26 +02:00
ipack
irqchip ARM: SoC platform changes for 3.17 2014-08-08 11:14:29 -07:00
isdn drivers: isdn: eicon: xdi_msg.h: Fix typo in #ifndef 2014-08-22 11:31:30 -07:00
leds ARM: SoC driver changes for 3.17 2014-08-08 11:34:32 -07:00
lguest mm/vmalloc.c: clean up map_vm_area third argument 2014-08-06 18:01:19 -07:00
macintosh == Changes to existing drivers == 2014-08-07 17:23:16 -07:00
mailbox mailbox/omap: add a parent structure for every IP instance 2014-07-29 01:57:25 -07:00
mcb
md dm cache: fix race causing dirty blocks to be marked as clean 2014-09-10 11:20:47 -04:00
media media: use pci_zalloc_consistent 2014-08-08 15:57:28 -07:00
memory memory: Freescale CoreNet Coherency Fabric error reporting driver 2014-07-29 19:26:30 -05:00
memstick
message mptfusion: tweak null pointer checks 2014-07-25 17:16:58 -04:00
mfd drivers/mfd/rtsx_usb.c: export device table 2014-08-14 10:56:15 -06:00
misc ARM: SoC driver changes for 3.17 2014-08-08 11:34:32 -07:00
mmc PCI changes for the v3.17 merge window (part 2): 2014-08-14 18:10:33 -06:00
mtd No significant changes, mostly small fixes here and there. The more important 2014-08-13 17:42:11 -06:00
net net: ethernet: broadcom: bnx2x: Remove redundant #ifdef 2014-08-22 11:29:58 -07:00
nfc NFC: st21nfca: Adding P2P support to st21nfca in Initiator & Target mode 2014-07-23 01:14:41 +02:00
ntb
nubus
of of/irq: Fix lookup to use 'interrupts-extended' property first 2014-08-16 09:03:58 +01:00
oprofile
parisc
parport drivers/parport/parport_ip32.c: use PTR_ERR_OR_ZERO 2014-08-08 15:57:25 -07:00
pci PCI changes for v3.17 (part 3): 2014-08-19 09:45:31 -05:00
pcmcia Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2014-08-07 08:50:34 -07:00
phy ARM: SoC driver changes for 3.17 2014-08-08 11:34:32 -07:00
pinctrl ARM: SoC driver changes for 3.17 2014-08-08 11:34:32 -07:00
platform Revert "platform/x86/toshiba-apci.c possible bad if test?" 2014-08-20 08:18:18 -07:00
pnp ACPI / PNP: Fix acpi_pnp_match() 2014-07-30 00:23:09 +02:00
power ARM: SoC platform changes for 3.17 2014-08-08 11:14:29 -07:00
powercap
pps
ps3
ptp PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
pwm pwm: Fix period and polarity in pwm_get() for non-perfect matches 2014-08-18 10:58:43 +02:00
rapidio PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
ras
regulator == Changes to existing drivers == 2014-08-07 17:17:39 -07:00
remoteproc
reset
rpmsg
rtc Merge branch 'akpm' (second patchbomb from Andrew Morton) 2014-08-08 15:57:47 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-08-07 08:41:00 -07:00
sbus Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2014-08-05 18:57:18 -07:00
scsi SCSI fixes on 20140819 2014-08-20 18:20:50 -05:00
sfi
sh sh: intc: Confine SH_INTC to platforms that need it 2014-08-22 12:28:16 +09:00
sn
soc
spi ARM: SoC cleanups for 3.17 2014-08-08 11:00:26 -07:00
spmi
ssb
staging Merge branch 'akpm' (second patchbomb from Andrew Morton) 2014-08-08 15:57:47 -07:00
target SCSI misc on 20140806 2014-08-06 20:10:32 -07:00
tc
thermal Merge branches 'exynos-fix', 'for-rc', 'int3403-fix', 'misc', 'rcar-thermal' and 'sti-thermal' of .git into next 2014-07-22 10:13:00 +08:00
thunderbolt
tty The branch contains the following device tree changes the v3.17 merge 2014-08-14 09:53:39 -06:00
uio
usb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-08-06 21:03:53 -07:00
uwb uwb/whci: use correct structure type name in sizeof 2014-08-01 15:48:08 -07:00
vfio drivers/vfio: Enable VFIO if EEH is not supported 2014-08-08 10:39:16 -06:00
vhost
video PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
virt
virtio virtio: Replace DEFINE_PCI_DEVICE_TABLE macro use 2014-07-27 21:07:15 +09:30
vlynq
vme vme: bridges: use pci_zalloc_consistent 2014-08-08 15:57:30 -07:00
w1
watchdog Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-08-07 08:47:00 -07:00
xen PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
zorro
Kconfig Char / Misc driver patches for 3.17-rc1 2014-08-04 17:32:24 -07:00
Makefile Driver core patches for 3.17-rc1 2014-08-04 18:34:04 -07:00