Lukas Czerner dfaa2ef68e loop: add discard support for loop devices ... This commit adds discard support for loop devices. Discard is usually supported by SSD and thinly provisioned devices as a method for reclaiming unused space. This is no different than trying to reclaim back space which is not used by the file system on the image, but it still occupies space on the host file system. We can do the reclamation on file system which does support hole punching. So when discard request gets to the loop driver we can translate that to punch a hole to the underlying file, hence reclaim the free space. This is very useful for trimming down the size of the image to only what is really used by the file system on that image. Fstrim may be used for that purpose. It has been tested on ext4, xfs and btrfs with the image file systems ext4, ext3, xfs and btrfs. ext4, or ext6 image on ext4 file system has some problems but it seems that ext4 punch hole implementation is somewhat flawed and it is unrelated to this commit. Also this is a very good method of validating file systems punch hole implementation. Note that when encryption is used, discard support is disabled, because using it might leak some information useful for possible attacker. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>		2011-08-19 14:50:46 +02:00
..
accessibility
acpi	Merge branch 'battery' into release	2011-08-05 22:16:42 -04:00
amba
ata	Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6	2011-08-02 21:17:02 -10:00
atm	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
auxdisplay
base	PM / Runtime: Allow _put_sync() from interrupts-disabled context	2011-08-05 21:45:20 +02:00
bcma	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-07-25 13:56:39 -07:00
block	loop: add discard support for loop devices	2011-08-19 14:50:46 +02:00
bluetooth
cdrom
char	net: Compute protocol sequence numbers and fragment IDs using MD5.	2011-08-06 18:33:19 -07:00
clk
clocksource	Merge branch 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-07-23 10:34:47 -07:00
connector	proc_fork_connector: a lockless ->real_parent usage is not safe	2011-07-28 18:26:32 -07:00
cpufreq	Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6	2011-07-26 09:21:09 -07:00
cpuidle	cpuidle: stop depending on pm_idle	2011-08-03 19:06:37 -04:00
crypto	n2_crypto: Attach on Niagara-T3.	2011-07-28 01:30:07 -07:00
dca
dio
dma	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx	2011-08-04 16:43:43 -10:00
edac	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
eisa	eisa/pci_eisa.c: fix BUG introduced by 005bdad7b8	2011-08-04 06:32:51 -10:00
firewire	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
firmware	Merge branch 'pstore-efi' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6	2011-08-02 21:18:39 -10:00
gpio	Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6	2011-08-01 06:13:48 -10:00
gpu	Revert "drm/i915: Try enabling RC6 by default (again)"	2011-08-05 10:56:29 +01:00
hid	Merge branches 'roccat', 'upstream' and 'wiimote' into for-linus	2011-07-22 22:47:08 +02:00
hwmon	Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging	2011-07-30 08:57:57 -10:00
hwspinlock
i2c	i2c-eg20t : Fix the issue of Combined R/W transfer mode	2011-07-27 00:02:28 +01:00
ide	drivers/ide/cy82c693.c: Add missing pci_dev_put	2011-08-04 01:30:34 -07:00
idle
ieee802154
infiniband	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending	2011-07-27 13:21:40 -07:00
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2011-08-03 22:00:09 -10:00
iommu
isdn	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2011-07-28 05:58:19 -07:00
leds	arch/arm/mach-ux500/board-u5500.c: calibrate ALS input voltage	2011-07-25 20:57:15 -07:00
lguest	lguest: Fix in/out emulation	2011-07-22 14:39:51 +09:30
macintosh
mca
md	dm table: set flush capability based on underlying devices	2011-08-02 12:32:08 +01:00
media	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6	2011-07-30 00:08:53 -07:00
memstick
message	Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6	2011-07-30 08:36:02 -10:00
mfd	mfd: Fix mismatch in twl4030 mutex lock-unlock	2011-07-31 23:28:27 +02:00
misc	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
mmc	mmc: sdhci-esdhc-imx: add device tree probe support	2011-07-27 09:31:39 +08:00
mtd	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-07-25 13:56:39 -07:00
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2011-08-05 06:42:01 -10:00
nfc	NFC: pn533: use after free in pn533_disconnect()	2011-07-26 16:27:24 -04:00
nubus
of	Revert "dt: add of_alias_scan and of_alias_get_id"	2011-08-04 11:26:24 +01:00
oprofile	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
parisc
parport	Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6	2011-07-25 23:09:27 -07:00
pci	Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6	2011-08-02 21:17:02 -10:00
pcmcia	Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6	2011-07-31 06:23:08 -10:00
platform	acer-wmi: support Lenovo ideapad S205 wifi switch	2011-08-05 15:21:52 -04:00
pnp	Merge 'akpm' patch series	2011-07-25 21:00:19 -07:00
power	Merge git://git.infradead.org/battery-2.6	2011-07-31 06:24:50 -10:00
pps
ps3
ptp
rapidio
regulator	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6	2011-08-01 14:05:46 -10:00
rtc	rtc-omap: fix initialization of control register	2011-08-03 14:25:20 -10:00
s390	[S390] qdio: Use kstrtoul_from_user	2011-08-03 16:44:21 +02:00
sbus	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
scsi	Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6	2011-07-30 08:36:02 -10:00
sfi
sh	Merge branch 'sh-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-3.x	2011-08-01 06:10:16 -10:00
sn
spi	spi/pl022: remove function cannot exit	2011-08-02 14:54:11 +01:00
ssb	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-07-25 13:56:39 -07:00
staging	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6	2011-07-30 00:08:53 -07:00
target	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending	2011-08-03 15:12:09 -10:00
tc
telephony
thermal	thermal: make THERMAL_HWMON implementation fully internal	2011-08-02 14:51:57 -04:00
tty	sh: Fix boot crash related to SCI	2011-08-07 15:51:45 -07:00
uio	Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6	2011-07-25 23:06:24 -07:00
usb	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6	2011-07-30 00:08:53 -07:00
uwb
vhost	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
video	savagedb: Fix typo causing regression in savage4 series video chip detection	2011-08-06 12:02:40 -07:00
virt	drivers/virt: add missing linux/interrupt.h to fsl_hypervisor.c	2011-07-22 09:24:39 -05:00
virtio	virtio: expose for non-virtualization users too	2011-07-23 16:20:30 +09:30
vlynq
w1	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
watchdog	watchdog: Cleanup WATCHDOG_CORE help text	2011-08-02 08:23:07 +00:00
xen	xen/self-balloon: Add dependency on tmem.	2011-08-03 14:34:57 -04:00
zorro
Kconfig	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc	2011-07-25 22:59:39 -07:00
Makefile	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc	2011-07-25 22:59:39 -07:00