linux/drivers
Song Liu 07e8336484 md/r5cache: shift complex rmw from read path to write path
Write back cache requires a complex RMW mechanism, where old data is
read into dev->orig_page for prexor, and then xor is done with
dev->page. This logic is already implemented in the write path.

However, current read path is not awared of this requirement. When
the array is optimal, the RMW is not required, as the data are
read from raid disks. However, when the target stripe is degraded,
complex RMW is required to generate right data.

To keep read path as clean as possible, we handle read path by
flushing degraded, in-journal stripes before processing reads to
missing dev.

Specifically, when there is read requests to a degraded stripe
with data in journal, handle_stripe_fill() calls
r5c_make_stripe_write_out() and exits. Then handle_stripe_dirtying()
will do the complex RMW and flush the stripe to RAID disks. After
that, read requests are handled.

There is one more corner case when there is non-overwrite bio for
the missing (or out of sync) dev. handle_stripe_dirtying() will not
be able to process the non-overwrite bios without constructing the
data in handle_stripe_fill(). This is fixed by delaying non-overwrite
bios in handle_stripe_dirtying(). So handle_stripe_fill() works on
these bios after the stripe is flushed to raid disks.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2017-01-24 11:20:15 -08:00
..
accessibility
acpi Merge branches 'acpi-scan', 'acpi-sysfs', 'acpi-wdat' and 'acpi-tables' 2017-01-06 14:36:30 +01:00
amba
android
ata Merge branch 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2016-12-13 15:30:50 -08:00
atm Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
auxdisplay
base PM / domains: Fix 'may be used uninitialized' build warning 2016-12-31 21:52:07 +01:00
bcma
block zram: support BDI_CAP_STABLE_WRITES 2017-01-10 18:31:55 -08:00
bluetooth Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-12-16 10:24:44 -08:00
bus cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
cdrom Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
char clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
clk One fix for a broken driver on Renesas RZ/A1 SoCs with bootloaders that don't 2017-01-06 15:35:27 -08:00
clocksource Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
connector
cpufreq Merge branch 'pm-cpufreq' 2017-01-06 14:34:52 +01:00
cpuidle Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-12-27 17:51:36 -08:00
dax libnvdimm for 4.10 2016-12-18 15:49:10 -08:00
dca
devfreq PM / devfreq: exynos-bus: Fix the wrong return value 2017-01-03 00:21:45 +01:00
dio Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
dma ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
dma-buf
edac Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
eisa
extcon sound updates for 4.10-rc1 2016-12-14 11:14:28 -08:00
firewire
firmware PSCI fixes for v4.10 2017-01-04 16:38:39 +01:00
fmc
fpga
gpio gpio: Move freeing of GPIO hogs before numbing of the device 2016-12-30 09:11:21 +01:00
gpu Merge branch 'drm-fixes-4.10' of git://people.freedesktop.org/~agd5f/linux into drm-fixes 2017-01-09 09:47:19 +10:00
hid HID: i2c-hid: Add sleep between POWER ON and RESET 2017-01-11 21:55:35 +01:00
hsi
hv clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
hwmon hwmon: (lm90) fix temp1_max_alarm attribute 2017-01-02 10:15:28 -08:00
hwspinlock
hwtracing coresight/etm3/4x: Consolidate hotplug state space 2016-12-25 10:47:44 +01:00
i2c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ide Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
idle Power management material for v4.10-rc1 2016-12-13 10:41:53 -08:00
iio First round of IIO fixes for the 4.10 cycle. 2017-01-02 16:59:44 +01:00
infiniband net/mlx4_core: Fix raw qp flow steering rules under SRIOV 2016-12-29 14:17:40 -05:00
input ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
iommu IOMMU Fixes for Linux v4.10-rc2 2017-01-06 10:49:36 -08:00
ipack
irqchip Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
isdn Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
leds cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
lguest Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
lightnvm Char/Misc driver patches for 4.10-rc1 2016-12-13 12:11:01 -08:00
macintosh Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mailbox ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
mcb
md md/r5cache: shift complex rmw from read path to write path 2017-01-24 11:20:15 -08:00
media ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
memory
memstick Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block 2016-12-13 10:19:16 -08:00
message Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mfd - New Device Support 2016-12-19 08:16:26 -08:00
misc mei: move write cb to completion on credentials failures 2017-01-04 18:22:44 +01:00
mmc Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mtd Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
net Merge branch 'akpm' (patches from Andrew) 2017-01-11 11:15:15 -08:00
nfc
ntb ntb_transport: Remove unnecessary call to ntb_peer_spad_read 2016-12-23 16:11:07 -05:00
nubus Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
nvdimm libnvdimm for 4.10 2016-12-18 15:49:10 -08:00
nvme Merge branch 'nvme-4.10' of git://git.infradead.org/nvme into for-linus 2016-12-22 11:54:46 -07:00
nvmem nvmem: fix nvmem_cell_read() return type doc 2017-01-04 18:22:47 +01:00
of pci-v4.10-changes 2016-12-15 12:46:48 -08:00
oprofile Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
parisc Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
parport Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
pci ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
pcmcia drivers/pcmcia/m32r_pcc.c: check return from add_pcc_socket 2016-12-12 18:55:06 -08:00
perf cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
phy SCSI misc on 20161213 2016-12-14 10:49:33 -08:00
pinctrl pinctrl: samsung: Fix the width of PINCFG_TYPE_DRV bitfields for Exynos5433 2016-12-30 14:27:42 +01:00
platform platform/x86: fujitsu-laptop: use brightness_set_blocking for LED-setting callbacks 2016-12-28 12:38:10 +02:00
pnp Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
power ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
powercap
pps
ps3
ptp Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-12 19:56:15 -08:00
pwm pwm: Changes for v4.10-rc1 2016-12-15 11:45:13 -08:00
rapidio
ras
regulator - New Device Support 2016-12-19 08:16:26 -08:00
remoteproc Revert "remoteproc: Merge table_ptr and cached_table pointers" 2016-12-30 03:26:31 -08:00
reset ARM: SoC driver updates for v4.10 2016-12-15 16:03:25 -08:00
rpmsg rpmsg: virtio_rpmsg_bus: fix channel creation 2016-12-30 03:12:11 -08:00
rtc ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
s390 ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
sbus Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
scsi ibmvscsis: Fix srp_transfer_data fail return code 2017-01-10 09:32:14 -08:00
sfi
sh lib: radix-tree: check accounting of existing slot replacement users 2016-12-12 18:55:08 -08:00
sn
soc powerpc updates for 4.10 2016-12-16 09:26:42 -08:00
spi dmaengine updates for 4.10-rc1 2016-12-14 20:42:45 -08:00
spmi
ssb
staging staging: octeon: Call SET_NETDEV_DEV() 2017-01-03 17:11:50 +01:00
target target: support XCOPY requests without parameters 2017-01-10 08:41:30 -08:00
tc
thermal Power management material for v4.10-rc1 2016-12-13 10:41:53 -08:00
thunderbolt Char/Misc driver patches for 4.10-rc1 2016-12-13 12:11:01 -08:00
tty Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
uio uio-hv-generic: store physical addresses instead of virtual 2016-12-10 14:57:58 +01:00
usb USB: fix problems with duplicate endpoint addresses 2017-01-05 19:38:40 +01:00
uwb
vfio vfio-pci: Handle error from pci_iomap 2017-01-04 08:34:39 -07:00
vhost Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-12-16 10:24:44 -08:00
video video: fbdev: cobalt_lcdfb: Handle return NULL error from devm_ioremap 2017-01-04 12:58:45 +01:00
virt
virtio virtio_mmio: Set dev.release() to avoid warning 2016-12-16 00:13:39 +02:00
vlynq
vme
w1
watchdog Watchdog updates for v4.10 2016-12-24 11:27:45 -08:00
xen Merge branch 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb 2017-01-06 10:53:21 -08:00
zorro Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
Kconfig
Makefile