linux/drivers
Minchan Kim 08eee69fcf zram: remove init_lock in zram_make_request
Admin could reset zram during I/O operation going on so we have used
zram->init_lock as read-side lock in I/O path to prevent sudden zram
meta freeing.

However, the init_lock is really troublesome.  We can't do call
zram_meta_alloc under init_lock due to lockdep splat because
zram_rw_page is one of the function under reclaim path and hold it as
read_lock while other places in process context hold it as write_lock.
So, we have used allocation out of the lock to avoid lockdep warn but
it's not good for readability and fainally, I met another lockdep splat
between init_lock and cpu_hotplug from kmem_cache_destroy during working
zsmalloc compaction.  :(

Yes, the ideal is to remove horrible init_lock of zram in rw path.  This
patch removes it in rw path and instead, add atomic refcount for meta
lifetime management and completion to free meta in process context.
It's important to free meta in process context because some of resource
destruction needs mutex lock, which could be held if we releases the
resource in reclaim context so it's deadlock, again.

As a bonus, we could remove init_done check in rw path because
zram_meta_get will do a role for it, instead.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Ganesh Mahendran <opensource.ganesh@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
..
accessibility
acpi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-02-10 20:01:30 -08:00
amba ARM: 8256/1: driver coamba: add device binding path 'driver_override' 2015-02-10 10:23:15 +00:00
android
ata SCSI misc on 20150209 2015-02-11 10:28:45 -08:00
atm atm: remove deprecated use of pci api 2015-01-18 00:28:41 -05:00
auxdisplay
base ACPI and power management updates for v3.20-rc1 2015-02-10 15:09:41 -08:00
bcma bcma: implement host code support for PCIe Gen 2 devices 2015-01-29 10:54:43 +02:00
block zram: remove init_lock in zram_make_request 2015-02-12 18:54:12 -08:00
bluetooth Bluetooth: btusb: Add support for Lite-On (04ca) Broadcom based, BCM43142 2015-02-03 08:57:14 +01:00
bus mvebu fixes for 3.19. (Part 4) 2015-01-23 14:08:13 -08:00
cdrom
char Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2015-02-11 20:25:11 -08:00
clk Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-02-10 20:01:30 -08:00
clocksource Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2015-02-12 08:51:56 -08:00
connector
coresight
cpufreq ACPI and power management updates for v3.20-rc1 2015-02-10 15:09:41 -08:00
cpuidle arm64 updates for 3.20: 2015-02-11 18:03:54 -08:00
crypto Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
dca
devfreq ACPI and power management updates for v3.20-rc1 2015-02-10 15:09:41 -08:00
dio
dma resources: Move struct resource_list_entry from ACPI into resource core 2015-02-05 15:09:25 +01:00
dma-buf
edac EDAC, mv64x60_edac: Fix an error code in probe() 2015-01-30 17:00:43 +01:00
eisa
extcon Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
firewire firewire: sbp2: replace card lock by target lock 2014-12-10 20:53:21 +01:00
firmware arm64 updates for 3.20: 2015-02-11 18:03:54 -08:00
fmc
gpio Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2015-02-12 08:51:56 -08:00
gpu sound updates for 3.20-rc1 2015-02-11 08:51:59 -08:00
hid Merge branches 'for-3.19/upstream-fixes', 'for-3.20/apple', 'for-3.20/betop', 'for-3.20/lenovo', 'for-3.20/logitech', 'for-3.20/rmi', 'for-3.20/upstream' and 'for-3.20/wacom' into for-linus 2015-02-09 11:17:45 +01:00
hsi hsi: nokia-modem: fix uninitialized device pointer 2015-01-04 20:19:30 +01:00
hv ACPICA: Resources: Provide common part for struct acpi_resource_address structures. 2015-01-26 16:09:56 +01:00
hwmon hwmon: (tmp102) add hibernation callbacks 2015-02-03 12:17:12 -08:00
hwspinlock
i2c i2c: sh_mobile: terminate DMA reads properly 2015-01-30 17:58:43 +01:00
ide Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
idle
iio Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-02-11 09:32:08 -08:00
infiniband Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-02-10 20:01:30 -08:00
input Merge branch 'next' into for-linus 2015-02-10 11:35:36 -08:00
iommu IOMMU Updates for Linux v3.20 2015-02-12 09:16:56 -08:00
ipack
irqchip Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2015-02-06 08:28:54 -08:00
isdn drivers: isdn: isdnloop: isdnloop.c: Remove parenthesis around return values, as specified in CodingStyle. 2015-02-05 15:40:23 -08:00
leds leds: netxbig: fix oops at probe time 2015-01-13 13:49:01 -08:00
lguest
macintosh macintosh: therm_pm72: delete deprecated driver 2014-12-19 19:32:47 +01:00
mailbox Merge branch 'mailbox-devel' of git://git.linaro.org/landing-teams/working/fujitsu/integration 2015-02-11 12:56:40 -08:00
mcb mcb: mcb-pci: Only remap the 1st 0x200 bytes of BAR 0 2015-01-09 15:46:37 -08:00
md Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-02-09 14:28:42 -08:00
media mm: gup: use get_user_pages_unlocked 2015-02-11 17:06:05 -08:00
memory memory/fsl-corenet-cf: Add t1040 support 2015-01-29 22:57:43 -06:00
memstick
message
mfd - Avoid platform ID collision in da9052 2015-01-21 18:29:44 +12:00
misc powerpc updates for 3.20 2015-02-11 18:15:38 -08:00
mmc mmc: sdhci-s3c: solve problem with sleeping in atomic context 2015-02-04 13:39:14 +01:00
mtd MTD updates for 3.19: 2014-12-17 09:59:26 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-02-10 20:01:30 -08:00
nfc NFC: nci: Move NFCEE discovery logic 2015-02-04 09:15:18 +01:00
ntb
nubus
of DeviceTree changes for 3.20: 2015-02-12 08:58:43 -08:00
oprofile
parisc parisc/PCI: Clip bridge windows to fit in upstream windows 2015-01-16 10:04:43 -06:00
parport parport: parport_atari: Remove obsolete IRQ_TYPE_SLOW 2015-01-15 13:44:50 +01:00
pci ACPI and power management updates for v3.20-rc1 2015-02-10 15:09:41 -08:00
pcmcia Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
phy SCSI misc on 20150209 2015-02-11 10:28:45 -08:00
pinctrl This is the bulk of pin control changes for the v3.20 cycle: 2015-02-11 11:23:13 -08:00
platform Revert "platform: x86: dell-laptop: Add support for keyboard backlight" 2015-01-23 11:10:32 -08:00
pnp ACPI: Return translation offset when parsing ACPI address space resources 2015-02-03 22:27:21 +01:00
power power_supply: 88pm860x: Fix leaked power supply on probe fail 2015-01-28 15:08:10 +01:00
powercap powercap / RAPL: add IDs for future Xeon CPUs 2014-12-17 02:35:42 +01:00
pps
ps3 powerpc/ps3: Fix sys-manager-core sparse warnings 2015-01-22 17:31:21 +11:00
ptp
pwm pwm: Changes for v3.19-rc1 2014-12-17 10:10:51 -08:00
rapidio rapidio/tsi721: use PCI define for Max_Read_Request_Size 2015-01-27 08:14:26 -06:00
ras
regulator Merge remote-tracking branches 'regulator/topic/rk808', 'regulator/topic/rpm', 'regulator/topic/rt5033' and 'regulator/topic/tps65023' into regulator-next 2015-02-08 11:16:30 +08:00
remoteproc Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
reset reset: sunxi: fix spinlock initialization 2015-01-16 19:11:31 -08:00
rpmsg
rtc Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-02-09 17:53:53 -08:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2015-02-11 17:42:32 -08:00
sbus
scsi mm: gup: use get_user_pages_unlocked 2015-02-11 17:06:05 -08:00
sfi
sh
sn
soc Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-12-15 15:52:01 -08:00
spi Merge remote-tracking branch 'spi/topic/xilinx' into spi-next 2015-02-08 11:17:01 +08:00
spmi
ssb ssb: Fix Sparse error in main 2015-01-29 10:17:56 +02:00
staging oom: add helpers for setting and clearing TIF_MEMDIE 2015-02-11 17:06:03 -08:00
target netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
tc
thermal Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-01-27 16:59:56 -08:00
thunderbolt
tty Merge branch 'akpm' (patches from Andrew) 2015-02-11 18:23:28 -08:00
uio Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
usb xilinx usb2 gadget: get rid of incredibly annoying compile warning 2015-02-11 10:52:56 -08:00
uwb
vfio vfio-pci: Fix the check on pci device type in vfio_pci_probe() 2015-01-07 10:29:11 -07:00
vhost Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-02-05 14:33:28 -08:00
video mm: gup: use get_user_pages_unlocked 2015-02-11 17:06:05 -08:00
virt
virtio virtio_pci: document why we defer kfree 2015-01-06 16:35:36 +02:00
vlynq
vme
w1 Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
watchdog watchdog: drop owner assignment from platform_drivers 2015-01-21 14:52:34 +01:00
xen SCSI misc on 20150209 2015-02-11 10:28:45 -08:00
zorro
Kconfig drivers/Kconfig: remove duplicate entry for soc 2015-01-25 20:26:42 +08:00
Makefile drivers: Move iommu/ before gpu/ in Makefile 2014-12-22 11:47:37 +02:00