James Bottomley 39c60a0948 [SCSI] sd: fix array cache flushing bug causing performance problems ... Some arrays synchronize their full non volatile cache when the sd driver sends a SYNCHRONIZE CACHE command. Unfortunately, they can have Terrabytes of this and we send a SYNCHRONIZE CACHE for every barrier if an array reports it has a writeback cache. This leads to massive slowdowns on journalled filesystems. The fix is to allow userspace to turn off the writeback cache setting as a temporary measure (i.e. without doing the MODE SELECT to write it back to the device), so even though the device reported it has a writeback cache, the user, knowing that the cache is non volatile and all they care about is filesystem correctness, can turn that bit off in the kernel and avoid the performance ruinous (and safety irrelevant) SYNCHRONIZE CACHE commands. The way you do this is add a 'temporary' prefix when performing the usual cache setting operations, so echo temporary write through > /sys/class/scsi_disk/<disk>/cache_type Reported-by: Ric Wheeler <rwheeler@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>		2013-05-02 16:15:54 -07:00
..
accessibility
acpi	Power management and ACPI updates for 3.10-rc1	2013-04-30 15:21:02 -07:00
amba
ata	1) More ACPI fixes, cleanups	2013-04-30 16:13:36 -07:00
atm	atm: he: use mdelay instead of large udelay constants	2013-04-29 13:26:48 -04:00
auxdisplay
base	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2013-05-01 13:20:04 -07:00
bcma
block	aoe: replace kmalloc and then memcpy with kmemdup	2013-04-30 17:04:08 -07:00
bluetooth	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
bus
cdrom
char	Merge branch 'akpm' (incoming from Andrew)	2013-04-30 17:37:43 -07:00
clk	Power management and ACPI updates for 3.10-rc1	2013-04-30 15:21:02 -07:00
clocksource	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-04-30 08:15:40 -07:00
connector
cpufreq	Merge branch 'pm-cpufreq'	2013-04-29 00:08:46 +02:00
cpuidle	cpuidle: add maintainer entry	2013-04-26 22:30:25 +02:00
crypto	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
dca
devfreq
dio
dma	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2013-04-22 20:32:51 -04:00
edac	Merge branch 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac	2013-04-30 10:00:49 -07:00
eisa	PCI changes for the v3.10 merge window:	2013-04-29 09:30:25 -07:00
extcon
firewire
firmware	dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()	2013-04-30 17:04:04 -07:00
gpio	These are the pinctrl changes for v3.10:	2013-04-29 09:40:35 -07:00
gpu	Power management and ACPI updates for 3.10-rc1	2013-04-30 15:21:02 -07:00
hid	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid	2013-04-30 09:37:55 -07:00
hsi
hv	Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-04-30 08:41:21 -07:00
hwmon	Highlights:	2013-04-30 15:15:24 -07:00
hwspinlock
i2c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
ide
idle	Merge branch 'pm-cpuidle'	2013-04-28 01:54:49 +02:00
iio
infiniband	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2013-05-01 13:20:04 -07:00
iommu	Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-04-30 08:40:35 -07:00
ipack
irqchip	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
isdn	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
leds
lguest	lguest: rename random32() to prandom_u32()	2013-04-29 18:28:43 -07:00
macintosh
mailbox
md	MD: ignore discard request for hard disks of hybid raid1/raid10 array	2013-04-30 14:49:36 +10:00
media	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
memory
memstick	drivers/memstick/host/r592.c: make r592_pm_ops static	2013-04-30 17:04:08 -07:00
message	i2o: check copy_from_user() size parameter	2013-04-30 17:04:04 -07:00
mfd	Highlights:	2013-04-30 15:15:24 -07:00
misc	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
mmc	mmc: rename random32() to prandom_u32()	2013-04-29 18:28:42 -07:00
mtd	mtdchar: remove no-longer-used vma helpers	2013-04-19 10:05:39 -07:00
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
nfc
ntb
nubus
of	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
oprofile
parisc
parport
pci	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
pcmcia
pinctrl	pinctrl: move subsystem mutex to pinctrl_dev struct	2013-04-26 17:01:35 +02:00
platform	Merge branch 'acpica'	2013-04-28 01:53:50 +02:00
pnp	Merge branch 'pnp'	2013-04-28 01:54:41 +02:00
power	Highlights:	2013-04-30 15:15:24 -07:00
pps	pps: pps_kc_hardpps_lock can be static	2013-04-30 17:04:08 -07:00
ps3
ptp
pwm
rapidio
regulator	Merge remote-tracking branch 'regulator/topic/wm8994' into v3.9-rc8	2013-04-28 02:13:50 +01:00
remoteproc	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
rpmsg	drivers/rpmsg/virtio_rpmsg_bus.c: fix error return code in rpmsg_probe()	2013-04-29 18:28:13 -07:00
rtc	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
s390	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
sbus
scsi	[SCSI] sd: fix array cache flushing bug causing performance problems	2013-05-02 16:15:54 -07:00
sfi
sh
sn
spi	spi: Updates for v3.10	2013-04-29 16:38:41 -07:00
ssb	ssb: implement ssb spuravoid for chipid BCM43222	2013-04-26 08:42:22 -04:00
ssbi
staging	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
target	tcm_fc: Check for aborted sequence	2013-04-25 01:05:28 -07:00
tc
thermal
tty	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2013-05-01 13:20:04 -07:00
uio
usb	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2013-05-01 13:20:04 -07:00
uwb	uwb: rename random32() to prandom_u32()	2013-04-29 18:28:43 -07:00
vfio	PCI changes for the v3.10 merge window:	2013-04-29 09:30:25 -07:00
vhost	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
video	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
virt
virtio
vlynq
vme
w1	drivers/w1/slaves/w1_ds2760.c: fix the error handling in w1_ds2760_add_slave()	2013-04-30 17:04:08 -07:00
watchdog
xen	zcache/tmem: Better error checking on frontswap_register_ops return value.	2013-04-30 17:04:01 -07:00
zorro
Kconfig	kconfig menu: move Virtualization drivers near other virtualization options	2013-04-30 17:04:09 -07:00
Makefile	USB patches for 3.10-rc1	2013-04-29 12:19:23 -07:00