linux/drivers
Ed Cashin fb32975d1b aoe: adjust ref of head for compound page tails
Fix a BUG which can trigger when direct-IO is used with AOE.

As discussed previously, the fact that some users of the block layer
provide bios that point to pages with a zero _count means that it is not
OK for the network layer to do a put_page on the skb frags during an
skb_linearize, so the aoe driver gets a reference to pages in bios and
puts the reference before ending the bio.  And because it cannot use
get_page on a page with a zero _count, it manipulates the value
directly.

It is not OK to increment the _count of a compound page tail, though,
since the VM layer will VM_BUG_ON a non-zero _count.  Block users that
do direct I/O can result in the aoe driver seeing compound page tails in
bios.  In that case, the same logic works as long as the head of the
compound page is used instead of the tails.  This patch handles compound
pages and does not BUG.

It relies on the block layer user leaving the relationship between the
page tail and its head alone for the duration between the submission of
the bio and its completion, whether successful or not.

Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13 17:57:48 -07:00
..
accessibility printk: move braille console support into separate braille.[ch] files 2013-07-31 14:41:03 -07:00
acpi ACPI: Try harder to resolve _ADR collisions for bridges 2013-08-07 22:55:00 +02:00
amba
ata pata_imx: expose module alias for loading from device-tree 2013-07-29 12:13:08 -04:00
atm
auxdisplay
base regmap: cache: Make sure to sync the last register in a block 2013-08-05 15:51:09 +01:00
bcma
block aoe: adjust ref of head for compound page tails 2013-08-13 17:57:48 -07:00
bluetooth Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2013-07-31 15:11:50 -04:00
bus
cdrom
char More virtio console fixes than I'm happy with, but all real issues, 2013-08-08 09:32:20 -07:00
clk
clocksource clocksource+irqchip: delete __cpuinit usage from all related files 2013-07-14 19:36:57 -04:00
connector
cpufreq cpufreq: rename ignore_nice as ignore_nice_load 2013-08-07 22:25:06 +02:00
cpuidle Revert "cpuidle: Quickly notice prediction failure for repeat mode" 2013-07-29 13:32:29 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2013-07-24 11:05:18 -07:00
dca
devfreq
dio
dma ARM: SoC fixes for v3.11-rc 2013-08-08 09:28:08 -07:00
edac EDAC: Fix lockdep splat 2013-07-23 16:01:28 -07:00
eisa
extcon
firewire firewire: fix libdc1394/FlyCap2 iso event regression 2013-07-27 20:24:36 +02:00
firmware dmi_scan: add comments on dmi_present() and the loop in dmi_scan_machine() 2013-07-31 14:41:02 -07:00
fmc
gpio gpio_msm: Fix build error due to missing err.h 2013-07-31 00:34:31 +02:00
gpu Merge tag 'drm-intel-fixes-2013-08-08' of git://people.freedesktop.org/~danvet/drm-intel into drm-fixes 2013-08-09 09:09:37 +10:00
hid Revert "HID: hid-logitech-dj: querying_devices was never set" 2013-08-09 11:34:19 +02:00
hsi
hv Drivers: hv: balloon: Do not post pressure status if interrupted 2013-07-16 23:19:19 -07:00
hwmon hwmon: (adt7470) Fix incorrect return code check 2013-08-08 12:43:07 -07:00
hwspinlock
i2c i2c: Fix Kontron PLD prescaler calculation 2013-08-05 10:31:18 +02:00
ide Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide 2013-07-10 18:15:41 -07:00
idle
iio iio: ti_am335x_adc: Fix wrong samples received on 1st read 2013-07-21 18:27:35 +01:00
infiniband Merge branches 'cma', 'cxgb3', 'cxgb4', 'ipoib', 'misc', 'mlx4', 'mlx5', 'nes', 'ocrdma' and 'qib' into for-next 2013-07-31 14:24:06 -07:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2013-07-13 18:05:13 -07:00
iommu IOMMU Updates for Linux 3.11 2013-07-10 14:46:40 -07:00
ipack
irqchip clocksource+irqchip: delete __cpuinit usage from all related files 2013-07-14 19:36:57 -04:00
isdn Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
leds
lguest
macintosh powerpc/windfarm: Fix noisy slots-fan on Xserve (rm31) 2013-08-01 13:11:47 +10:00
mailbox
md 2 more bugfixes for md in 3.11 2013-07-26 11:20:10 -07:00
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2013-08-09 15:04:09 -07:00
memory
memstick
message
mfd For the 3.11 merge we only have one new MFD driver for the Kontron PLD. 2013-07-10 11:10:27 -07:00
misc Char/Misc patches for 3.11-rc3 2013-07-26 11:36:12 -07:00
mmc ARM: pxa: propagate errors from regulator_enable() to pxamci 2013-07-23 12:15:15 -07:00
mtd A couple of fixes and clean-ups, allow for assigning user-defined 2013-07-05 12:09:48 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-08-03 15:00:23 -07:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
ntb
nubus
of of/irq: init struct resource to 0 in of_irq_to_resource() 2013-07-22 19:40:38 +01:00
oprofile drivers: delete __cpuinit usage from all remaining drivers files 2013-07-14 19:36:59 -04:00
parisc parisc: Fix interrupt routing for C8000 serial ports 2013-07-31 23:42:32 +02:00
parport
pci ACPI: Try harder to resolve _ADR collisions for bridges 2013-08-07 22:55:00 +02:00
pcmcia
pinctrl pinctrl: fix a memleak when freeing maps 2013-07-25 17:18:36 +02:00
platform x86 platform drivers: fix gpio leak 2013-07-10 15:42:51 -04:00
pnp PNP / ACPI: avoid garbage in resource name 2013-07-18 01:38:59 +02:00
power Nothing exciting this time, just assorted fixes and cleanups. 2013-07-10 11:13:00 -07:00
pps
ps3
ptp
pwm
rapidio rapidio: fix use after free in rio_unregister_scan() 2013-07-31 14:41:02 -07:00
regulator For the 3.11 merge we only have one new MFD driver for the Kontron PLD. 2013-07-10 11:10:27 -07:00
remoteproc Trivial remoteproc fixes by Suman Anna, Wei Yongjun and Thomas Meyer. 2013-07-11 12:35:09 -07:00
reset
rpmsg
rtc drivers/rtc/rtc-twl.c: fix: rtcX/wakealarm attribute isn't created 2013-07-31 14:41:03 -07:00
s390 s390/dasd: fix hanging devices after path events 2013-07-30 16:17:25 +02:00
sbus
scsi SCSI fixes on 20130811 2013-08-11 16:32:26 -07:00
sfi
sh
sn
spi spi: spi-davinci: Fix direction in dma_map_single() 2013-07-29 20:27:54 +01:00
ssb Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2013-07-13 14:52:21 -07:00
staging staging: zcache: fix "zcache=" kernel parameter 2013-07-29 11:45:09 -07:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2013-07-11 12:57:19 -07:00
tc
thermal Thermal: Fix lockup of cpu_down() 2013-07-22 09:34:46 +08:00
tty parisc: Fix interrupt routing for C8000 serial ports 2013-07-31 23:42:32 +02:00
uio
usb usb: xhci: add missing dma-mapping.h includes 2013-07-31 11:27:18 -07:00
uwb
vfio vfio-pci: Avoid deadlock on remove 2013-07-24 16:36:41 -06:00
vhost vhost: more fixes for 3.11 2013-07-23 14:38:20 -07:00
video fbdev fixes: 2013-08-09 11:52:34 -07:00
virt
virtio No real surprises. 2013-07-10 14:50:58 -07:00
vlynq
vme
w1
watchdog Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2013-07-13 14:52:21 -07:00
xen Fixes: 2013-07-31 11:37:43 -07:00
zorro
Kconfig For the 3.11 merge we only have one new MFD driver for the Kontron PLD. 2013-07-10 11:10:27 -07:00
Makefile For the 3.11 merge we only have one new MFD driver for the Kontron PLD. 2013-07-10 11:10:27 -07:00