22 Sep, 2016
1 commit
-
bio_free_pages is introduced in commit 1dfa0f68c040
("block: add a helper to free bio bounce buffer pages"),
we can reuse the func in other modules after it was
imported.Cc: Christoph Hellwig
Cc: Jens Axboe
Cc: Mike Snitzer
Cc: Shaohua Li
Signed-off-by: Guoqing Jiang
Acked-by: Kent Overstreet
Signed-off-by: Jens Axboe
19 Aug, 2016
3 commits
-
The original error was thought to be corruption, but was actually caused by:
make-bcache --data-offset N
where N was in bytes and should have been in sectors. While userspace
tools should be updated to check --data-offset beyond end of volume,
hopefully this will help others that might not have noticed the units.Signed-off-by: Eric Wheeler
Cc: Kent Overstreet -
This patch fixes a cachedev registration-time allocation deadlock.
This can deadlock on boot if your initrd auto-registeres bcache devices:Allocator thread:
[ 720.727614] INFO: task bcache_allocato:3833 blocked for more than 120 seconds.
[ 720.732361] [] schedule+0x37/0x90
[ 720.732963] [] bch_bucket_alloc+0x188/0x360 [bcache]
[ 720.733538] [] ? prepare_to_wait_event+0xf0/0xf0
[ 720.734137] [] bch_prio_write+0x19d/0x340 [bcache]
[ 720.734715] [] bch_allocator_thread+0x3ff/0x470 [bcache]
[ 720.735311] [] ? __schedule+0x2dc/0x950
[ 720.735884] [] ? invalidate_buckets+0x980/0x980 [bcache]Registration thread:
[ 720.710403] INFO: task bash:3531 blocked for more than 120 seconds.
[ 720.715226] [] schedule+0x37/0x90
[ 720.715805] [] __bch_btree_map_nodes+0x12d/0x150 [bcache]
[ 720.716409] [] ? bch_btree_insert_check_key+0x1c0/0x1c0 [bcache]
[ 720.717008] [] bch_btree_insert+0xf4/0x170 [bcache]
[ 720.717586] [] ? prepare_to_wait_event+0xf0/0xf0
[ 720.718191] [] bch_journal_replay+0x14a/0x290 [bcache]
[ 720.718766] [] ? ttwu_do_activate.constprop.94+0x5d/0x70
[ 720.719369] [] ? try_to_wake_up+0x1d4/0x350
[ 720.719968] [] run_cache_set+0x580/0x8e0 [bcache]
[ 720.720553] [] register_bcache+0xe2e/0x13b0 [bcache]
[ 720.721153] [] kobj_attr_store+0xf/0x20
[ 720.721730] [] sysfs_kf_write+0x3d/0x50
[ 720.722327] [] kernfs_fop_write+0x12a/0x180
[ 720.722904] [] __vfs_write+0x37/0x110
[ 720.723503] [] ? __sb_start_write+0x58/0x110
[ 720.724100] [] ? security_file_permission+0x23/0xa0
[ 720.724675] [] vfs_write+0xa9/0x1b0
[ 720.725275] [] ? do_audit_syscall_entry+0x6c/0x70
[ 720.725849] [] SyS_write+0x55/0xd0
[ 720.726451] [] ? do_page_fault+0x30/0x80
[ 720.727045] [] system_call_fastpath+0x12/0x71The fifo code in upstream bcache can't use the last element in the buffer,
which was the cause of the bug: if you asked for a power of two size,
it'd give you a fifo that could hold one less than what you asked for
rather than allocating a buffer twice as big.Signed-off-by: Kent Overstreet
Tested-by: Eric Wheeler
Cc: stable@vger.kernel.org -
register_cache() is supposed to return an error string on error so that
register_bcache() will will blkdev_put and cleanup other user counters,
but it does not set 'char *err' when cache_alloc() fails (eg, due to
memory pressure) and thus register_bcache() performs no cleanup.register_bcache() register_cache() | cache_alloc() ---/
Cc: Kent Overstreet
Cc: stable@vger.kernel.org
08 Aug, 2016
1 commit
-
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.No intended functional changes in this commit.
Signed-off-by: Jens Axboe
21 Jul, 2016
1 commit
-
Instead of a flag and an index just make sure an index of 0 means
no need to free the bvec array. Also move the constants related
to the bvec pools together and use a consistent naming scheme for
them.Signed-off-by: Christoph Hellwig
Reviewed-by: Johannes Thumshirn
Reviewed-by: Mike Christie
Signed-off-by: Jens Axboe
06 Jul, 2016
3 commits
-
We have assigned sb->block_size before the switch,
so remove the redundant one.Reviewed-by: Coly Li
Signed-off-by: Yijing Wang
Acked-by: Eric Wheeler
Signed-off-by: Jens Axboe -
There is no return in continue_at(), update the documentation.
Signed-off-by: Yijing Wang
Acked-by: Coly Li
Signed-off-by: Jens Axboe -
Cache_sb is not used in cache_alloc, and we have copied
sb info to cache->sb already, remove it.Reviewed-by: Coly Li
Signed-off-by: Yijing Wang
Signed-off-by: Jens Axboe
12 Jun, 2016
1 commit
-
alloc_workqueue replaces deprecated create_workqueue().
Dedicated workqueues have been used since bcache_wq and moving_gc_wq
are workqueues for writes and are being used on a memory reclaim path.
WQ_MEM_RECLAIM has been set to ensure forward progress under memory
pressure.
Since there are only a fixed number of work items, explicit concurrency
limit is unnecessary here.Signed-off-by: Bhaktipriya Shridhar
Acked-by: Tejun Heo
Signed-off-by: Jens Axboe
08 Jun, 2016
4 commits
-
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.Signed-off-by: Mike Christie
Reviewed-by: Christoph Hellwig
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe -
Separate the op from the rq_flag_bits and have bcache
set/get the bio using bio_set_op_attrs/bio_op.Signed-off-by: Mike Christie
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe -
We currently set REQ_WRITE/WRITE for all non READ IOs
like discard, flush, writesame, etc. In the next patches where we
no longer set up the op as a bitmap, we will not be able to
detect a operation direction like writesame by testing if REQ_WRITE is
set.This has bcache use the op_is_write helper which will do the right
thing.Signed-off-by: Mike Christie
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe -
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.Signed-off-by: Mike Christie
Fixed up fs/ext4/crypto.c
Signed-off-by: Jens Axboe
24 May, 2016
3 commits
-
bch_gc_thread() doesn't mark itself freezable, so calling try_to_freeze()
in its context is just an expensive no-op.Signed-off-by: Jiri Kosina
Signed-off-by: Jens Axboe -
bch_allocator_thread() is calling try_to_freeze(), but that's just an
expensive no-op given the fact that the thread is not marked freezable.Bucket allocator has to be up and running to the very last stages of the
suspend, as the bcache I/O that's in flight (think of writing an
hibernation image to a swap device served by bcache).Signed-off-by: Jiri Kosina
Signed-off-by: Jens Axboe -
bch_writeback_thread() is calling try_to_freeze(), but that's just an
expensive no-op given the fact that the thread is not marked freezable.I/O helper kthreads, exactly such as the bcache writeback thread, actually
shouldn't be freezable, because they are potentially necessary for
finalizing the image write-out.Signed-off-by: Jiri Kosina
Signed-off-by: Jens Axboe
13 Apr, 2016
1 commit
-
Signed-off-by: Jens Axboe
Reviewed-by: Christoph Hellwig
09 Mar, 2016
3 commits
-
When bch_cache_set_alloc() fails to kzalloc the cache_set, the
asyncronous closure handling tries to dereference a cache_set that
hadn't yet been allocated inside of cache_set_flush() which is called
by __cache_set_unregister() during cleanup. This appears to happen only
during an OOM condition on bcache_register.Signed-off-by: Eric Wheeler
Cc: stable@vger.kernel.org -
Fix null pointer dereference by changing register_cache() to return an int
instead of being void. This allows it to return -ENOMEM or -ENODEV and
enables upper layers to handle the OOM case without NULL pointer issues.See this thread:
http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3521Fixes this error:
gargamel:/sys/block/md5/bcache# echo /dev/sdh2 > /sys/fs/bcache/registerbcache: register_cache() error opening sdh2: cannot allocate memory
BUG: unable to handle kernel NULL pointer dereference at 00000000000009b8
IP: [] cache_set_flush+0x102/0x15c [bcache]
PGD 120dff067 PUD 1119a3067 PMD 0
Oops: 0000 [#1] SMP
Modules linked in: veth ip6table_filter ip6_tables
(...)
CPU: 4 PID: 3371 Comm: kworker/4:3 Not tainted 4.4.2-amd64-i915-volpreempt-20160213bc1 #3
Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
Workqueue: events cache_set_flush [bcache]
task: ffff88020d5dc280 ti: ffff88020b6f8000 task.ti: ffff88020b6f8000
RIP: 0010:[] [] cache_set_flush+0x102/0x15c [bcache]Signed-off-by: Eric Wheeler
Tested-by: Marc MERLIN
Cc: -
The bch_writeback_thread might BUG_ON in read_dirty() if
dc->sb==BDEV_STATE_DIRTY and bch_sectors_dirty_init has not yet completed
its related initialization. This patch downs the dc->writeback_lock until
after initialization is complete, thus preventing bch_writeback_thread
from proceeding prematurely.See this thread:
http://thread.gmane.org/gmane.linux.kernel.bcache.devel/3453Signed-off-by: Eric Wheeler
Tested-by: Marc MERLIN
Cc:
Signed-off-by: Jens Axboe
22 Jan, 2016
1 commit
-
Pull block driver updates from Jens Axboe:
"This is the block driver pull request for 4.5, with the exception of
NVMe, which is in a separate branch and will be posted after this one.This pull request contains:
- A set of bcache stability fixes, which have been acked by Kent.
These have been used and tested for more than a year by the
community, so it's about time that they got in.- A set of drbd updates from the drbd team (Andreas, Lars, Philipp)
and Markus Elfring, Oleg Drokin.- A set of fixes for xen blkback/front from the usual suspects, (Bob,
Konrad) as well as community based fixes from Kiri, Julien, and
Peng.- A 2038 time fix for sx8 from Shraddha, with a fix from me.
- A small mtip32xx cleanup from Zhu Yanjun.
- A null_blk division fix from Arnd"
* 'for-4.5/drivers' of git://git.kernel.dk/linux-block: (71 commits)
null_blk: use sector_div instead of do_div
mtip32xx: restrict variables visible in current code module
xen/blkfront: Fix crash if backend doesn't follow the right states.
xen/blkback: Fix two memory leaks.
xen/blkback: make st_ statistics per ring
xen/blkfront: Handle non-indirect grant with 64KB pages
xen-blkfront: Introduce blkif_ring_get_request
xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule()
xen/blkback: Free resources if connect_ring failed.
xen/blocks: Return -EXX instead of -1
xen/blkback: make pool of persistent grants and free pages per-queue
xen/blkback: get the number of hardware queues/rings from blkfront
xen/blkback: pseudo support for multi hardware queues/rings
xen/blkback: separate ring information out of struct xen_blkif
xen/blkfront: correct setting for xen_blkif_max_ring_order
xen/blkfront: make persistent grants pool per-queue
xen/blkfront: Remove duplicate setting of ->xbdev.
xen/blkfront: Cleanup of comments, fix unaligned variables, and syntax errors.
xen/blkfront: negotiate number of queues/rings to be used with backend
xen/blkfront: split per device io_lock
...
04 Jan, 2016
1 commit
-
Signed-off-by: Al Viro
31 Dec, 2015
8 commits
-
Previously, it would only scan the entire disk if it was starting from
the very start of the disk - i.e. if the previous scan got to the end.This was broken by refill_full_stripes(), which updates last_scanned so
that refill_dirty was never triggering the searched_from_start path.But if we change refill_dirty() to always scan the entire disk if
necessary, regardless of what last_scanned was, the code gets cleaner
and we fix that bug too.Signed-off-by: Kent Overstreet
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe -
Added a safeguard in the shutdown case. At least while not being
attached it is also possible to trigger a kernel bug by writing into
writeback_running. This change adds the same check before trying to
wake up the thread for that case.Signed-off-by: Stefan Bader
Cc: Kent Overstreet
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe -
Allows to use register, not register_quiet in udev to avoid "device_busy" error.
The initial patch proposed at https://lkml.org/lkml/2013/8/26/549 by Gabriel de Perthuis
does not unlock the mutex and hangs the kernel.See http://thread.gmane.org/gmane.linux.kernel.bcache.devel/2594 for the discussion.
Cc: Denis Bychkov
Cc: Kent Overstreet
Cc: Eric Wheeler
Cc: Gabriel de Perthuis
Cc: stable@vger.kernel.orgSigned-off-by: Jens Axboe
-
In bcache_init() function it forgot to unregister reboot notifier if
bcache fails to unregister a block device. This commit fixes this.Signed-off-by: Zheng Liu
Tested-by: Joshua Schmid
Tested-by: Eric Wheeler
Cc: Kent Overstreet
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe -
Signed-off-by: Al Viro
Tested-by: Joshua Schmid
Tested-by: Eric Wheeler
Cc: Kent Overstreet
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe -
This bug can be reproduced by the following script:
#!/bin/bash
bcache_sysfs="/sys/fs/bcache"
function clear_cache()
{
if [ ! -e $bcache_sysfs ]; then
echo "no bcache sysfs"
exit
ficset_uuid=$(ls -l $bcache_sysfs|head -n 2|tail -n 1|awk '{print $9}')
sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/detach"
sleep 5
sudo sh -c "echo $cset_uuid > /sys/block/sdb/sdb1/bcache/attach"
}for ((i=0;i] ? warn_slowpath_common+0x87/0xc0
[ 276.122650] [] ? warn_slowpath_fmt+0x46/0x50
[ 276.139361] [] ? sysfs_add_one+0xb8/0xd0
[ 276.156012] [] ? sysfs_do_create_link+0x12b/0x170
[ 276.172682] [] ? sysfs_create_link+0x13/0x20
[ 276.189282] [] ? bcache_device_link+0xc1/0x110 [bcache]
[ 276.205993] [] ? bch_cached_dev_attach+0x478/0x4f0 [bcache]
[ 276.222794] [] ? bch_cached_dev_store+0x627/0x780 [bcache]
[ 276.239680] [] ? alloc_pages_current+0xaa/0x110
[ 276.256594] [] ? sysfs_write_file+0xe5/0x170
[ 276.273364] [] ? vfs_write+0xb8/0x1a0
[ 276.290133] [] ? sys_write+0x51/0x90
[ 276.306368] [] ? system_call_fastpath+0x16/0x1b
[ 276.322301] ---[ end trace 9f5d4fcdd0c3edfb ]---
[ 276.338241] ------------[ cut here ]------------
[ 276.354109] WARNING: at /home/wenqing.lz/bcache/bcache/super.c:720
bcache_device_link+0xdf/0x110 [bcache]() (Tainted: P W --------------- )
[ 276.386017] Hardware name: Tecal RH2285
[ 276.401430] Couldn't create device cache set symlinks
[ 276.401759] Modules linked in: bcache tcp_diag inet_diag ipmi_devintf ipmi_si ipmi_msghandler
bonding 8021q garp stp llc ipv6 ext3 jbd loop sg iomemory_vsl(P) bnx2 microcode serio_raw i2c_i801
i2c_core iTCO_wdt iTCO_vendor_support i7core_edac edac_core shpchp ext4 jbd2 mbcache megaraid_sas
pata_acpi ata_generic ata_piix dm_mod [last unloaded: scsi_wait_scan]
[ 276.465477] Pid: 2765, comm: sh Tainted: P W --------------- 2.6.32 #1
[ 276.482169] Call Trace:
[ 276.498610] [] ? warn_slowpath_common+0x87/0xc0
[ 276.515405] [] ? warn_slowpath_fmt+0x46/0x50
[ 276.532059] [] ? bcache_device_link+0xdf/0x110 [bcache]
[ 276.548808] [] ? bch_cached_dev_attach+0x478/0x4f0 [bcache]
[ 276.565569] [] ? bch_cached_dev_store+0x627/0x780 [bcache]
[ 276.582418] [] ? alloc_pages_current+0xaa/0x110
[ 276.599341] [] ? sysfs_write_file+0xe5/0x170
[ 276.616142] [] ? vfs_write+0xb8/0x1a0
[ 276.632607] [] ? sys_write+0x51/0x90
[ 276.648671] [] ? system_call_fastpath+0x16/0x1b
[ 276.664756] ---[ end trace 9f5d4fcdd0c3edfc ]---We forget to clear BCACHE_DEV_UNLINK_DONE flag in bcache_device_attach()
function when we attach a backing device first time. After detaching this
backing device, this flag will be true and sysfs_remove_link() isn't called in
bcache_device_unlink(). Then when we attach this backing device again,
sysfs_create_link() will return EEXIST error in bcache_device_link().So the fix is trival and we clear this flag in bcache_device_link().
Signed-off-by: Zheng Liu
Tested-by: Joshua Schmid
Tested-by: Eric Wheeler
Cc: Kent Overstreet
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe -
Signed-off-by: Takashi Iwai
Tested-by: Eric Wheeler
Cc: Kent Overstreet
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe -
Subject : [PATCH v2] bcache: fix a livelock in btree lock
Date : Wed, 25 Feb 2015 20:32:09 +0800 (02/25/2015 04:32:09 AM)This commit tries to fix a livelock in bcache. This livelock might
happen when we causes a huge number of cache misses simultaneously.When we get a cache miss, bcache will execute the following path.
->cached_dev_make_request()
->cached_dev_read()
->cached_lookup()
->bch->btree_map_keys()
->btree_root() bch_btree_map_keys_recurse() |
->cache_lookup_fn() |
->cached_dev_cache_miss() |
->bch_btree_insert_check_key() -|
[If btree->seq is not equal to seq + 1, we should return
EINTR and traverse btree again.]In bch_btree_insert_check_key() function we first need to check upgrade
flag (op->lock == -1), and when this flag is true we need to release
read btree->lock and try to take write btree->lock. During taking and
releasing this write lock, btree->seq will be monotone increased in
order to prevent other threads modify this in cache miss (see btree.h:74).
But if there are some cache misses caused by some requested, we could
meet a livelock because btree->seq is always changed by others. Thus no
one can make progress.This commit will try to take write btree->lock if it encounters a race
when we traverse btree. Although it sacrifice the scalability but we
can ensure that only one can modify the btree.Signed-off-by: Zheng Liu
Tested-by: Joshua Schmid
Tested-by: Eric Wheeler
Cc: Joshua Schmid
Cc: Zhu Yanhai
Cc: Kent Overstreet
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe
11 Nov, 2015
1 commit
-
Pull block IO poll support from Jens Axboe:
"Various groups have been doing experimentation around IO polling for
(really) fast devices. The code has been reviewed and has been
sitting on the side for a few releases, but this is now good enough
for coordinated benchmarking and further experimentation.Currently O_DIRECT sync read/write are supported. A framework is in
the works that allows scalable stats tracking so we can auto-tune
this. And we'll add libaio support as well soon. Fow now, it's an
opt-in feature for test purposes"* 'for-4.4/io-poll' of git://git.kernel.dk/linux-block:
direct-io: be sure to assign dio->bio_bdev for both paths
directio: add block polling support
NVMe: add blk polling support
block: add block polling support
blk-mq: return tag/queue combo in the make_request_fn handlers
block: change ->make_request_fn() and users to return a queue cookie
08 Nov, 2015
2 commits
-
Pull trivial updates from Jiri Kosina:
"Trivial stuff from trivial tree that can be trivially summed up as:- treewide drop of spurious unlikely() before IS_ERR() from Viresh
Kumar- cosmetic fixes (that don't really affect basic functionality of the
driver) for pktcdvd and bcache, from Julia Lawall and Petr Mladek- various comment / printk fixes and updates all over the place"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
bcache: Really show state of work pending bit
hwmon: applesmc: fix comment typos
Kconfig: remove comment about scsi_wait_scan module
class_find_device: fix reference to argument "match"
debugfs: document that debugfs_remove*() accepts NULL and error values
net: Drop unlikely before IS_ERR(_OR_NULL)
mm: Drop unlikely before IS_ERR(_OR_NULL)
fs: Drop unlikely before IS_ERR(_OR_NULL)
drivers: net: Drop unlikely before IS_ERR(_OR_NULL)
drivers: misc: Drop unlikely before IS_ERR(_OR_NULL)
UBI: Update comments to reflect UBI_METAONLY flag
pktcdvd: drop null test before destroy functions -
No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.Signed-off-by: Jens Axboe
Acked-by: Christoph Hellwig
Acked-by: Keith Busch
06 Nov, 2015
1 commit
-
WORK_STRUCT_PENDING is a mask for testing the pending bit.
test_bit() expects the number of the bit and we need to
use WORK_STRUCT_PENDING_BIT there.Also work_data_bits() is defined in workqueues.h now.
I have noticed this just by chance when looking how
WORK_STRUCT_PENDING_BIT is used. The change is compile
tested.Signed-off-by: Petr Mladek
Signed-off-by: Jiri Kosina
14 Aug, 2015
1 commit
-
The bcache driver has always accepted arbitrarily large bios and split
them internally. Now that every driver must accept arbitrarily large
bios this code isn't nessecary anymore.Cc: linux-bcache@vger.kernel.org
Signed-off-by: Kent Overstreet
[dpark: add more description in commit message]
Signed-off-by: Dongsu Park
Signed-off-by: Ming Lin
Signed-off-by: Jens Axboe
29 Jul, 2015
1 commit
-
Currently we have two different ways to signal an I/O error on a BIO:
(1) by clearing the BIO_UPTODATE flag
(2) by returning a Linux errno value to the bi_end_io callbackThe first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario. Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.Signed-off-by: Christoph Hellwig
Reviewed-by: Hannes Reinecke
Reviewed-by: NeilBrown
Signed-off-by: Jens Axboe
17 Jul, 2015
1 commit
-
Some drivers use it now, others just set the limits field manually.
But in preparation for splitting this into a hard and soft limit,
ensure that they all call the proper function for setting the hw
limit for discards.Reviewed-by: Jeff Moyer
Signed-off-by: Jens Axboe
11 Jul, 2015
1 commit
-
This is horribly confusing, it breaks the flow of the code without
it being apparent in the caller.Signed-off-by: Jens Axboe
Acked-by: Christoph Hellwig
01 Jul, 2015
1 commit
-
Kent's email address in MAINTAINERS seems to be invalid.
This was his last sign-off address, so use that if appropriate.Fix the S: status entry while there.
Signed-off-by: Joe Perches
Acked-by: Kent Overstreet
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
