kernel_optimize_test/drivers
Mikulas Patocka a8d41b59f3 dm snapshot: fix race during exception creation
Fix a race condition that returns incorrect data when a write causes an
exception to be allocated whilst a read is still in flight.

The race condition happens as follows:
* A read to non-reallocated sector in the snapshot is submitted so that the
  read is routed to the original device.
* A write to the original device is submitted. The write causes an exception
  that reallocates the block.  The write proceeds.
* The original read is dequeued and reads the wrong data.

This race can be triggered with CFQ scheduler and one thread writing and
multiple threads reading simultaneously.

(This patch relies upon the earlier dm-kcopyd-per-device.patch to avoid a
deadlock.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-07-21 12:00:34 +01:00
..
accessibility
acpi Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
amba
ata Merge commit 'origin/master' 2008-07-16 11:07:59 +10:00
atm firmware: convert Ambassador ATM driver to request_firmware() 2008-07-10 14:49:39 +01:00
auxdisplay Miguel Ojeda has moved 2008-07-04 10:40:05 -07:00
base Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
block hd.c: remove the #include <linux/mc146818rtc.h> 2008-07-16 20:33:48 +02:00
bluetooth Merge branch 'for-2.6.27' of git://git.infradead.org/users/dwmw2/firmware-2.6 2008-07-14 16:54:07 -07:00
cdrom cdrom: revert commit 22a9189 (cdrom: use kmalloced buffers instead of buffers on stack) 2008-07-04 09:52:14 +02:00
char Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-fixes-2.6 2008-07-17 10:55:07 -07:00
clocksource Fix printk format warning in clocksource/acpi_pm.c 2008-07-15 11:01:39 -07:00
connector CONNECTOR: add a proc entry to list connectors 2008-06-27 20:03:24 -07:00
cpufreq Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq 2008-06-09 11:27:55 -07:00
cpuidle smp_call_function: get rid of the unused nonatomic/retry argument 2008-06-26 11:24:35 +02:00
crypto crypto: ixp4xx - Select CRYPTO_AUTHENC 2008-07-13 20:12:11 +08:00
dca
dio
dma
edac
eisa
firewire Merge branch 'sbp2-spindown' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 2008-07-15 12:39:44 -07:00
firmware Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git 2008-07-14 15:51:11 -07:00
gpio gpio: pca953x (i2c) handles max7310 too 2008-07-04 10:40:06 -07:00
gpu drm/radeon: fixup issue with radeon and PAT support. 2008-07-15 15:48:05 +10:00
hid Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
hwmon hwmon: (w83l786ng) Convert to a new-style i2c driver 2008-07-16 19:30:18 +02:00
i2c i2c: Convert the max6875 driver to a new-style i2c driver 2008-07-16 19:30:07 +02:00
ide Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-fixes-2.6 2008-07-17 10:55:07 -07:00
ieee1394 Merge branch 'sbp2-spindown' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 2008-07-15 12:39:44 -07:00
infiniband Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2008-07-15 18:58:04 -07:00
input Merge branch 'bkl-removal' of git://git.lwn.net/linux-2.6 2008-07-14 14:48:31 -07:00
isdn Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
leds
lguest Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
macintosh Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-build 2008-07-15 15:44:51 +10:00
mca
md dm snapshot: fix race during exception creation 2008-07-21 12:00:34 +01:00
media Merge branch 'for-2.6.27' of git://git.infradead.org/users/dwmw2/firmware-2.6 2008-07-14 16:54:07 -07:00
memstick
message Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2008-07-15 18:58:04 -07:00
mfd
misc fujitsu-laptop: depends on INPUT 2008-07-16 23:27:03 +02:00
mmc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc 2008-07-16 15:17:52 -07:00
mtd [MIPS] MTX-1 flash partition setup move to platform devices registration 2008-07-15 18:44:38 +01:00
net Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2 2008-07-17 10:55:51 -07:00
nubus
of OpenFirmware: Include <linux/of_i2c.h> from of_i2c.c. 2008-07-12 12:10:52 -06:00
oprofile
parisc parisc-eisa_eeprom: BKL pushdown 2008-07-02 15:06:24 -06:00
parport
pci Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
pcmcia Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-fixes-2.6 2008-07-17 10:55:07 -07:00
pnp PNPACPI: add support for HP vendor-specific CCSR descriptors 2008-07-16 23:27:07 +02:00
power power_supply: Fix race in power_supply_uevent 2008-06-10 02:13:51 +04:00
ps3
rapidio rapidio: fix device reference counting 2008-07-10 18:04:43 -07:00
rtc Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm 2008-07-14 16:06:58 -07:00
s390 [S390] dasd: use -EOPNOTSUPP instead of -ENOTSUPP 2008-07-17 17:22:10 +02:00
sbus Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
scsi scsi_dh: Verify "dev" is a sdev before accessing it. 2008-07-16 17:54:21 -07:00
serial PNP: add pnp_possible_config() -- can a device could be configured this way? 2008-07-16 23:27:06 +02:00
sh
sn
spi Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-build 2008-07-15 15:44:51 +10:00
ssb ssb-pcicore: Fix IRQ-vector init on embedded devices 2008-07-07 15:31:40 -04:00
tc
telephony phonedev: cdev lock_kernel() pushdown 2008-06-20 14:05:48 -06:00
thermal thermal: Create CONFIG_THERMAL_HWMON=n 2008-06-25 19:25:42 -04:00
uio Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
usb Merge branch 'for-2.6.27' of git://git.infradead.org/users/dwmw2/firmware-2.6 2008-07-14 16:54:07 -07:00
video Merge commit 'origin/master' 2008-07-16 11:07:59 +10:00
virtio virtio: Complete feature negotation before updating status 2008-06-15 13:46:16 -07:00
w1 w1/ds2482: Convert to a new-style driver 2008-07-16 19:30:07 +02:00
watchdog Merge commit 'origin/master' 2008-07-16 11:07:59 +10:00
xen Merge branch 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-14 13:43:24 -07:00
zorro
Kconfig
Makefile drm: reorganise drm tree to be more future proof. 2008-07-14 10:45:01 +10:00