23 May, 2012
1 commit
-
Pull cgroup updates from Tejun Heo:
"cgroup file type addition / removal is updated so that file types are
added and removed instead of individual files so that dynamic file
type addition / removal can be implemented by cgroup and used by
controllers. blkio controller changes which will come through block
tree are dependent on this. Other changes include res_counter cleanup
and disallowing kthread / PF_THREAD_BOUND threads to be attached to
non-root cgroups.There's a reported bug with the file type addition / removal handling
which can lead to oops on cgroup umount. The issue is being looked
into. It shouldn't cause problems for most setups and isn't a
security concern."Fix up trivial conflict in Documentation/feature-removal-schedule.txt
* 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
res_counter: Account max_usage when calling res_counter_charge_nofail()
res_counter: Merge res_counter_charge and res_counter_charge_nofail
cgroups: disallow attaching kthreadd or PF_THREAD_BOUND threads
cgroup: remove cgroup_subsys->populate()
cgroup: get rid of populate for memcg
cgroup: pass struct mem_cgroup instead of struct cgroup to socket memcg
cgroup: make css->refcnt clearing on cgroup removal optional
cgroup: use negative bias on css->refcnt to block css_tryget()
cgroup: implement cgroup_rm_cftypes()
cgroup: introduce struct cfent
cgroup: relocate __d_cgrp() and __d_cft()
cgroup: remove cgroup_add_file[s]()
cgroup: convert memcg controller to the new cftype interface
memcg: always create memsw files if CONFIG_CGROUP_MEM_RES_CTLR_SWAP
cgroup: convert all non-memcg controllers to the new cftype interface
cgroup: relocate cftype and cgroup_subsys definitions in controllers
cgroup: merge cft_release_agent cftype array into the base files array
cgroup: implement cgroup_add_cftypes() and friends
cgroup: build list of all cgroups under a given cgroupfs_root
cgroup: move cgroup_clear_directory() call out of cgroup_populate_dir()
...
22 May, 2012
1 commit
-
Pull s390 updates from Martin Schwidefsky:
"Just a random collection of bug-fixes and cleanups, nothing new in
this merge request."* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
s390/ap: Fix wrong or missing comments
s390/ap: move receive callback to message struct
s390/dasd: re-prioritize partition detection message
s390/qeth: reshuffle initialization
s390/qeth: cleanup drv attr usage
s390/claw: cleanup drv attr usage
s390/lcs: cleanup drv attr usage
s390/ctc: cleanup drv attr usage
s390/ccwgroup: remove ccwgroup_create_from_string
s390/qeth: stop using struct ccwgroup driver for discipline callbacks
s390/qeth: switch to ccwgroup_create_dev
s390/claw: switch to ccwgroup_create_dev
s390/lcs: switch to ccwgroup_create_dev
s390/ctcm: switch to ccwgroup_create_dev
s390/ccwgroup: exploit ccwdev_by_dev_id
s390/ccwgroup: introduce ccwgroup_create_dev
s390: fix race on TIF_MCCK_PENDING
s390/barrier: make use of fast-bcr facility
s390/barrier: cleanup barrier functions
s390/claw: remove "eieio" calls
...
16 May, 2012
1 commit
-
To avoid confusion while formatting a DASD device change the level of
the "Expected VOL1 label not found" message from warning to info.Signed-off-by: Stefan Haberland
Signed-off-by: Martin Schwidefsky
15 May, 2012
1 commit
-
6d1d8050b4bc8 "block, partition: add partition_meta_info to hd_struct"
added part_unpack_uuid() which assumes that the passed in buffer has
enough space for sprintfing "%pU" - 37 characters including '\0'.Unfortunately, b5af921ec0233 "init: add support for root devices
specified by partition UUID" supplied 33 bytes buffer to the function
leading to the following panic with stackprotector enabled.Kernel panic - not syncing: stack-protector: Kernel stack corrupted in: ffffffff81b14c7e
[] panic+0xba/0x1c6
[] ? printk_all_partitions+0x259/0x26xb
[] __stack_chk_fail+0x1b/0x20
[] printk_all_paritions+0x259/0x26xb
[] mount_block_root+0x1bc/0x27f
[] mount_root+0x57/0x5b
[] prepare_namespace+0x13d/0x176
[] ? release_tgcred.isra.4+0x330/0x30
[] kernel_init+0x155/0x15a
[] ? schedule_tail+0x27/0xb0
[] kernel_thread_helper+0x5/0x10
[] ? start_kernel+0x3c5/0x3c5
[] ? gs_change+0x13/0x13Increase the buffer size, remove the dangerous part_unpack_uuid() and
use snprintf() directly from printk_all_partitions().Signed-off-by: Tejun Heo
Reported-by: Szymon Gruszczynski
Cc: Will Drewry
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe
14 Apr, 2012
1 commit
-
Pull block core bits from Jens Axboe:
"It's a nice and quiet round this time, since most of the tricky stuff
has been pushed to 3.5 to give it more time to mature. After a few
hectic block IO core changes for 3.3 and 3.2, I'm quite happy with a
slow round.Really minor stuff in here, the only real functional change is making
the auto-unplug threshold a per-queue entity. The threshold is set so
that it's low enough that we don't hold off IO for too long, but still
big enough to get a nice benefit from the batched insert (and hence
queue lock cost reduction). For raid configurations, this currently
breaks down."* 'for-3.4/core' of git://git.kernel.dk/linux-block:
block: make auto block plug flush threshold per-disk based
Documentation: Add sysfs ABI change for cfq's target latency.
block: Make cfq_target_latency tunable through sysfs.
block: use lockdep_assert_held for queue locking
block: blk_alloc_queue_node(): use caller's GFP flags instead of GFP_KERNEL
07 Apr, 2012
1 commit
-
We do auto block plug flush to reduce latency, the threshold is 16
requests. This works well if the task is accessing one or two drives.
The problem is if the task is accessing a raid 0 device and the raid
disk number is big, say 8 or 16, 16/8 = 2 or 16/16=1, we will have
heavy lock contention.This patch makes the threshold per-disk based. The latency should be
still ok accessing one or two drives. The setup with application
accessing a lot of drives in the meantime uaually is big machine,
avoiding lock contention is more important, because any contention
will actually increase latency.Signed-off-by: Shaohua Li
Signed-off-by: Jens Axboe
02 Apr, 2012
3 commits
-
In cfq, when we calculate a time slice for a process(or a cfqq to
be precise), we have to consider the cfq_target_latency so that all the
sync request have an estimated latency(300ms) and it is controlled by
cfq_target_latency. But in some hadoop test, we have found that if
there are many processes doing sequential read(24 for example), the
throughput is bad because every process can only work for about 25ms
and the cfqq is switched. That leads to a higher disk seek. We can
achive the good throughput by setting low_latency=0, but then some
read's latency is too much for the application.So this patch makes cfq_target_latency tunable through sysfs so that
we can tune it and find some magic number which is not bad for both
the throughput and the read latency.Cc: Jens Axboe
Signed-off-by: Tao Ma
Signed-off-by: Jens Axboe -
Convert debug, freezer, cpuset, cpu_cgroup, cpuacct, net_prio, blkio,
net_cls and device controllers to use the new cftype based interface.
Termination entry is added to cftype arrays and populate callbacks are
replaced with cgroup_subsys->base_cftypes initializations.This is functionally identical transformation. There shouldn't be any
visible behavior change.memcg is rather special and will be converted separately.
Signed-off-by: Tejun Heo
Acked-by: Li Zefan
Cc: Paul Menage
Cc: Ingo Molnar
Cc: Peter Zijlstra
Cc: "David S. Miller"
Cc: Vivek Goyal -
blk-cgroup, netprio_cgroup, cls_cgroup and tcp_memcontrol
unnecessarily define cftype array and cgroup_subsys structures at the
top of the file, which is unconventional and necessiates forward
declaration of methods.This patch relocates those below the definitions of the methods and
removes the forward declarations. Note that forward declaration of
tcp_files[] is added in tcp_memcontrol.c for tcp_init_cgroup(). This
will be removed soon by another patch.This patch doesn't introduce any functional change.
Signed-off-by: Tejun Heo
Acked-by: Li Zefan
30 Mar, 2012
1 commit
-
Instead of an ugly open coded variant.
Cc: axboe@kernel.dk
Signed-off-by: Andi Kleen
Signed-off-by: Jens Axboe
23 Mar, 2012
1 commit
-
We should use the GFP flags that the caller specified instead of picking
our own. All the callers specify GFP_KERNEL so this doesn't make a
difference to how the kernel runs, it's just a cleanup.Signed-off-by: Dan Carpenter
Signed-off-by: Jens Axboe
21 Mar, 2012
2 commits
-
Pull cgroup changes from Tejun Heo:
"Out of the 8 commits, one fixes a long-standing locking issue around
tasklist walking and others are cleanups."* 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Walk task list under tasklist_lock in cgroup_enable_task_cg_list
cgroup: Remove wrong comment on cgroup_enable_task_cg_list()
cgroup: remove cgroup_subsys argument from callbacks
cgroup: remove extra calls to find_existing_css_set
cgroup: replace tasklist_lock with rcu_read_lock
cgroup: simplify double-check locking in cgroup_attach_proc
cgroup: move struct cgroup_pidlist out from the header file
cgroup: remove cgroup_attach_task_current_cg() -
Pull scheduler changes for v3.4 from Ingo Molnar
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
printk: Make it compile with !CONFIG_PRINTK
sched/x86: Fix overflow in cyc2ns_offset
sched: Fix nohz load accounting -- again!
sched: Update yield() docs
printk/sched: Introduce special printk_sched() for those awkward moments
sched/nohz: Correctly initialize 'next_balance' in 'nohz' idle balancer
sched: Cleanup cpu_active madness
sched: Fix load-balance wreckage
sched: Clean up parameter passing of proc_sched_autogroup_set_nice()
sched: Ditch per cgroup task lists for load-balancing
sched: Rename load-balancing fields
sched: Move load-balancing arguments into helper struct
sched/rt: Do not submit new work when PI-blocked
sched/rt: Prevent idle task boosting
sched/wait: Add __wake_up_all_locked() API
sched/rt: Document scheduler related skip-resched-check sites
sched/rt: Use schedule_preempt_disabled()
sched/rt: Add schedule_preempt_disabled()
sched/rt: Do not throttle when PI boosting
sched/rt: Keep period timer ticking when rt throttling is active
...
15 Mar, 2012
1 commit
-
Pull block fixes from Jens Axboe:
"Been sitting on this for a while, but lets get this out the door.
This fixes various important bugs for 3.3 final, along with a few more
trivial ones. Please pull!"* 'for-linus' of git://git.kernel.dk/linux-block:
block: fix ioc leak in put_io_context
block, sx8: fix pointer math issue getting fw version
Block: use a freezable workqueue for disk-event polling
drivers/block/DAC960: fix -Wuninitialized warning
drivers/block/DAC960: fix DAC960_V2_IOCTL_Opcode_T -Wenum-compare warning
block: fix __blkdev_get and add_disk race condition
block: Fix setting bio flags in drivers (sd_dif/floppy)
block: Fix NULL pointer dereference in sd_revalidate_disk
block: exit_io_context() should call elevator_exit_icq_fn()
block: simplify ioc_release_fn()
block: replace icq->changed with icq->flags
14 Mar, 2012
1 commit
-
When put_io_context is called, if ioc->icq_list is empty and refcount
is 1, kernel will not free the ioc.This is caught by following kmemleak:
unreferenced object 0xffff880036349fe0 (size 216):
comm "sh", pid 2137, jiffies 4294931140 (age 290579.412s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
01 00 01 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
backtrace:
[] kmemleak_alloc+0x26/0x50
[] kmem_cache_alloc_node+0x1cc/0x2a0
[] create_io_context_slowpath+0x27/0x130
[] get_task_io_context+0xbb/0xf0
[] copy_process+0x188e/0x18b0
[] do_fork+0x11b/0x420
[] sys_clone+0x28/0x30
[] stub_clone+0x13/0x20
[] 0xffffffffffffffffioc should be freed if ioc->icq_list is empty.
Signed-off-by: Xiaotian Feng
Acked-by: Vivek Goyal
Acked-by: Tejun Heo
Signed-off-by: Jens Axboe
02 Mar, 2012
3 commits
-
This patch (as1519) fixes a bug in the block layer's disk-events
polling. The polling is done by a work routine queued on the
system_nrt_wq workqueue. Since that workqueue isn't freezable, the
polling continues even in the middle of a system sleep transition.Obviously, polling a suspended drive for media changes and such isn't
a good thing to do; in the case of USB mass-storage devices it can
lead to real problems requiring device resets and even re-enumeration.The patch fixes things by creating a new system-wide, non-reentrant,
freezable workqueue and using it for disk-events polling.Signed-off-by: Alan Stern
CC:
Acked-by: Tejun Heo
Acked-by: Rafael J. Wysocki
Signed-off-by: Jens Axboe -
The following situation might occur:
__blkdev_get: add_disk:
register_disk()
get_gendisk()disk_block_events()
disk->ev == NULLdisk_add_events()
__disk_unblock_events()
disk->ev != NULL
--ev->blockThen we unblock events, when they are suppose to be blocked. This can
trigger events related block/genhd.c warnings, but also can crash in
sd_check_events() or other places.I'm able to reproduce crashes with the following scripts (with
connected usb dongle as sdb disk).DEV=/dev/sdb
ENABLE=/sys/bus/usb/devices/1-2/bConfigurationValuefunction stop_me()
{
for i in `jobs -p` ; do kill $i 2> /dev/null ; done
exit
}trap stop_me SIGHUP SIGINT SIGTERM
for ((i = 0; i < 10; i++)) ; do
while true; do fdisk -l $DEV 2>&1 > /dev/null ; done &
donewhile true ; do
echo 1 > $ENABLE
sleep 1
echo 0 > $ENABLE
doneI use the script to verify patch fixing oops in sd_revalidate_disk
http://marc.info/?l=linux-scsi&m=132935572512352&w=2
Without Jun'ichi Nomura patch titled "Fix NULL pointer dereference in
sd_revalidate_disk" or this one, script easily crash kernel within
a few seconds. With both patches applied I do not observe crash.
Unfortunately after some time (dozen of minutes), script will hung in:[ 1563.906432] [] schedule_timeout_uninterruptible+0x15/0x20
[ 1563.906437] [] msleep+0x15/0x20
[ 1563.906443] [] blk_drain_queue+0x32/0xd0
[ 1563.906447] [] blk_cleanup_queue+0xd0/0x170
[ 1563.906454] [] scsi_free_queue+0x3f/0x60
[ 1563.906459] [] __scsi_remove_device+0x6e/0xb0
[ 1563.906463] [] scsi_forget_host+0x4f/0x60
[ 1563.906468] [] scsi_remove_host+0x5a/0xf0
[ 1563.906482] [] quiesce_and_remove_host+0x5b/0xa0 [usb_storage]
[ 1563.906490] [] usb_stor_disconnect+0x13/0x20 [usb_storage]Anyway I think this patch is some step forward.
As drawback, I do not teardown on sysfs file create error, because I do
not know how to nullify disk->ev (since it can be used). However add_disk
error handling practically does not exist too, and things will work
without this sysfs file, except events will not be exported to user
space.Signed-off-by: Stanislaw Gruszka
Acked-by: Tejun Heo
Cc: stable@kernel.org
Signed-off-by: Jens Axboe -
Since 2.6.39 (1196f8b), when a driver returns -ENOMEDIUM for open(),
__blkdev_get() calls rescan_partitions() to remove
in-kernel partition structures and raise KOBJ_CHANGE uevent.However it ends up calling driver's revalidate_disk without open
and could cause oops.In the case of SCSI:
process A process B
----------------------------------------------
sys_open
__blkdev_get
sd_open
returns -ENOMEDIUM
scsi_remove_device
rescan_partitions
sd_revalidate_disk
Oopses are reported here:
http://marc.info/?l=linux-scsi&m=132388619710052This patch separates the partition invalidation from rescan_partitions()
and use it for -ENOMEDIUM case.Reported-by: Huajun Li
Signed-off-by: Jun'ichi Nomura
Acked-by: Tejun Heo
Cc: stable@kernel.org
Signed-off-by: Jens Axboe
01 Mar, 2012
1 commit
-
Merge reason: we'll queue up dependent patches.
Signed-off-by: Ingo Molnar
24 Feb, 2012
1 commit
-
From: Ben Hutchings
Extended VBLKs (those larger than the preset VBLK size) are divided
into fragments, each with its own VBLK header. Our LDM implementation
generally assumes that each VBLK is contiguous in memory, so these
fragments must be assembled before further processing.Currently the reassembly seems to be done quite wrongly - no VBLK
header is copied into the contiguous buffer, and the length of the
header is subtracted twice from each fragment. Also the total
length of the reassembled VBLK is calculated incorrectly.Signed-off-by: Ben Hutchings
Signed-off-by: Anton Altaparmakov
15 Feb, 2012
3 commits
-
While updating locking, b2efa05265 "block, cfq: unlink
cfq_io_context's immediately" moved elevator_exit_icq_fn() invocation
from exit_io_context() to the final ioc put. While this doesn't cause
catastrophic failure, it effectively removes task exit notification to
elevator and cause noticeable IO performance degradation with CFQ.On task exit, CFQ used to immediately expire the slice if it was being
used by the exiting task as no more IO would be issued by the task;
however, after b2efa05265, the notification is lost and disk could sit
idle needlessly, leading to noticeable IO performance degradation for
certain workloads.This patch renames ioc_exit_icq() to ioc_destroy_icq(), separates
elevator_exit_icq_fn() invocation into ioc_exit_icq() and invokes it
from exit_io_context(). ICQ_EXITED flag is added to avoid invoking
the callback more than once for the same icq.Walking icq_list from ioc side and invoking elevator callback requires
reverse double locking. This may be better implemented using RCU;
unfortunately, using RCU isn't trivial. e.g. RCU protection would
need to cover request_queue and queue_lock switch on cleanup makes
grabbing queue_lock from RCU unsafe. Reverse double locking should
do, at least for now.Signed-off-by: Tejun Heo
Reported-and-bisected-by: Shaohua Li
LKML-Reference:
Tested-by: Shaohua Li
Signed-off-by: Jens Axboe -
Reverse double lock dancing in ioc_release_fn() can be simplified by
just using trylock on the queue_lock and back out from ioc lock on
trylock failure. Simplify it.Signed-off-by: Tejun Heo
Tested-by: Shaohua Li
Signed-off-by: Jens Axboe -
icq->changed was used for ICQ_*_CHANGED bits. Rename it to flags and
access it under ioc->lock instead of using atomic bitops.
ioc_get_changed() is added so that the changed part can be fetched and
cleared as before.icq->flags will be used to carry other flags.
Signed-off-by: Tejun Heo
Tested-by: Shaohua Li
Signed-off-by: Jens Axboe
11 Feb, 2012
1 commit
-
11a3122f6c "block: strip out locking optimization in put_io_context()"
removed ioc_lock depth lockdep annoation along with locking
optimization; however, while recursing from put_io_context() is no
longer possible, ioc_release_fn() may still end up putting the last
reference of another ioc through elevator, which wlil grab ioc->lock
triggering spurious (as the ioc is always different one) A-A deadlock
warning.As this can only happen one time from ioc_release_fn(), using non-zero
subclass from ioc_release_fn() is enough. Use subclass 1.Signed-off-by: Tejun Heo
Signed-off-by: Jens Axboe
09 Feb, 2012
1 commit
-
We create "bsg" link if q->kobj.sd is not NULL, so remove it only
when the same condition is true.Fixes:
WARNING: at fs/sysfs/inode.c:323 sysfs_hash_and_remove+0x2b/0x77()
sysfs: can not remove 'bsg', no directory
Call Trace:
[] warn_slowpath_common+0x6a/0x7f
[] ? sysfs_hash_and_remove+0x2b/0x77
[] warn_slowpath_fmt+0x2b/0x2f
[] sysfs_hash_and_remove+0x2b/0x77
[] sysfs_remove_link+0x20/0x23
[] bsg_unregister_queue+0x40/0x6d
[] __scsi_remove_device+0x31/0x9d
[] scsi_forget_host+0x41/0x52
[] scsi_remove_host+0x71/0xe0
[] quiesce_and_remove_host+0x51/0x83 [usb_storage]
[] usb_stor_disconnect+0x18/0x22 [usb_storage]
[] usb_unbind_interface+0x4e/0x109
[] __device_release_driver+0x6b/0xa6
[] device_release_driver+0x17/0x22
[] bus_remove_device+0xd6/0xe6
[] device_del+0xf2/0x137
[] usb_disable_device+0x94/0x1a0Signed-off-by: Stanislaw Gruszka
Signed-off-by: Jens Axboe
08 Feb, 2012
2 commits
-
Plug merge calls two elevator callbacks outside queue lock -
elevator_allow_merge_fn() and elevator_bio_merged_fn(). Although
attempt_plug_merge() suggests that elevator is guaranteed to be there
through the existing request on the plug list, nothing prevents plug
merge from calling into dying or initializing elevator.For regular merges, bypass ensures elvpriv count to reach zero, which
in turn prevents merges as all !ELVPRIV requests get REQ_SOFTBARRIER
from forced back insertion. Plug merge doesn't check ELVPRIV, and, as
the requests haven't gone through elevator insertion yet, it doesn't
have SOFTBARRIER set allowing merges on a bypassed queue.This, for example, leads to the following crash during elevator
switch.BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: [] cfq_allow_merge+0x49/0xa0
PGD 112cbc067 PUD 115d5c067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
CPU 1
Modules linked in: deadline_ioschedPid: 819, comm: dd Not tainted 3.3.0-rc2-work+ #76 Bochs Bochs
RIP: 0010:[] [] cfq_allow_merge+0x49/0xa0
RSP: 0018:ffff8801143a38f8 EFLAGS: 00010297
RAX: 0000000000000000 RBX: ffff88011817ce28 RCX: ffff880116eb6cc0
RDX: 0000000000000000 RSI: ffff880118056e20 RDI: ffff8801199512f8
RBP: ffff8801143a3908 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff880118195708
R13: ffff880118052aa0 R14: ffff8801143a3d50 R15: ffff880118195708
FS: 00007f19f82cb700(0000) GS:ffff88011fc80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000008 CR3: 0000000112c6a000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process dd (pid: 819, threadinfo ffff8801143a2000, task ffff880116eb6cc0)
Stack:
ffff88011817ce28 ffff880118195708 ffff8801143a3928 ffffffff81391bba
ffff88011817ce28 ffff880118195708 ffff8801143a3948 ffffffff81391bf1
ffff88011817ce28 0000000000000000 ffff8801143a39a8 ffffffff81398e3e
Call Trace:
[] elv_rq_merge_ok+0x4a/0x60
[] elv_try_merge+0x21/0x40
[] blk_queue_bio+0x8e/0x390
[] generic_make_request+0xca/0x100
[] submit_bio+0x74/0x100
[] __blockdev_direct_IO+0x1ce2/0x3450
[] blkdev_direct_IO+0x57/0x60
[] generic_file_aio_read+0x6d5/0x760
[] do_sync_read+0xe2/0x120
[] vfs_read+0xc5/0x180
[] sys_read+0x51/0x90
[] system_call_fastpath+0x16/0x1bThere are multiple ways to fix this including making plug merge check
ELVPRIV; however,* Calling into elevator outside queue lock is confusing and
error-prone.* Requests on plug list aren't known to the elevator. They aren't on
the elevator yet, so there's no elevator specific state to update.* Given the nature of plug merges - collecting bio's for the same
purpose from the same issuer - elevator specific restrictions aren't
applicable.So, simply don't call into elevator methods from plug merge by moving
elv_bio_merged() from bio_attempt_*_merge() to blk_queue_bio(), and
using blk_try_merge() in attempt_plug_merge().This is based on Jens' patch to skip elevator_allow_merge_fn() from
plug merge.Note that this makes per-cgroup merged stats skip plug merging.
Signed-off-by: Tejun Heo
LKML-Reference:
Original-patch-by: Jens Axboe
Signed-off-by: Jens Axboe -
blk_rq_merge_ok() is the elevator-neutral part of merge eligibility
test. blk_try_merge() determines merge direction and expects the
caller to have tested elv_rq_merge_ok() previously.elv_rq_merge_ok() now wraps blk_rq_merge_ok() and then calls
elv_iosched_allow_merge(). elv_try_merge() is removed and the two
callers are updated to call elv_rq_merge_ok() explicitly followed by
blk_try_merge(). While at it, make rq_merge_ok() functions return
bool.This is to prepare for plug merge update and doesn't introduce any
behavior change.This is based on Jens' patch to skip elevator_allow_merge_fn() from
plug merge.Signed-off-by: Tejun Heo
LKML-Reference:
Original-patch-by: Jens Axboe
Signed-off-by: Jens Axboe
07 Feb, 2012
1 commit
-
put_io_context() performed a complex trylock dancing to avoid
deferring ioc release to workqueue. It was also broken on UP because
trylock was always assumed to succeed which resulted in unbalanced
preemption count.While there are ways to fix the UP breakage, even the most
pathological microbench (forced ioc allocation and tight fork/exit
loop) fails to show any appreciable performance benefit of the
optimization. Strip it out. If there turns out to be workloads which
are affected by this change, simpler optimization from the discussion
thread can be applied later.Signed-off-by: Tejun Heo
LKML-Reference:
Signed-off-by: Jens Axboe
06 Feb, 2012
1 commit
-
Meelis reported a warning:
WARNING: at kernel/timer.c:1122 run_timer_softirq+0x199/0x1ec()
Hardware name: 939Dual-SATA2
timer: cfq_idle_slice_timer+0x0/0xaa preempt leak: 00000102 -> 00000103
Modules linked in: sr_mod cdrom videodev media drm_kms_helper ohci_hcd ehci_hcd v4l2_compat_ioctl32 usbcore i2c_ali15x3 snd_seq drm snd_timer snd_seq
Pid: 0, comm: swapper Not tainted 3.3.0-rc2-00110-gd125666 #176
Call Trace:
[] warn_slowpath_common+0x7e/0x96
[] ? cfq_slice_expired+0x1d/0x1d
[] warn_slowpath_fmt+0x41/0x43
[] ? cfq_idle_slice_timer+0xa1/0xaa
[] ? cfq_slice_expired+0x1d/0x1d
[] run_timer_softirq+0x199/0x1ec
[] ? timekeeping_get_ns+0x12/0x31
[] ? apic_write+0x11/0x13
[] __do_softirq+0x74/0xfa
[] call_softirq+0x1a/0x30
[] do_softirq+0x31/0x68
[] irq_exit+0x3d/0xa3
[] smp_apic_timer_interrupt+0x6b/0x77
[] apic_timer_interrupt+0x69/0x70
[] ? sched_clock_cpu+0x73/0x7d
[] ? sched_clock_cpu+0x73/0x7d
[] ? default_idle+0x1e/0x32
[] ? default_idle+0x18/0x32
[] cpu_idle+0x87/0xd1
[] rest_init+0x85/0x89
[] start_kernel+0x2eb/0x2f8
[] x86_64_start_reservations+0x7e/0x82
[] x86_64_start_kernel+0xf0/0xf7this_q == locked_q is possible. There are two problems here:
1. In UP case, there is preemption counter issue as spin_trylock always
successes.
2. In SMP case, the loop breaks too earlier.Signed-off-by: Shaohua Li
Reported-by: Meelis Roos
Reported-by: Knut Petersen
Tested-by: Knut Petersen
Signed-off-by: Jens Axboe
03 Feb, 2012
1 commit
-
The argument is not used at all, and it's not necessary, because
a specific callback handler of course knows which subsys it
belongs to.Now only ->pupulate() takes this argument, because the handlers of
this callback always call cgroup_add_file()/cgroup_add_files().So we reduce a few lines of code, though the shrinking of object size
is minimal.16 files changed, 113 insertions(+), 162 deletions(-)
text data bss dec hex filename
5486240 656987 7039960 13183187 c928d3 vmlinux.o.orig
5486170 656987 7039960 13183117 c9288d vmlinux.oSigned-off-by: Li Zefan
Signed-off-by: Tejun Heo
27 Jan, 2012
1 commit
-
The block layer has some code trying to determine if two CPUs share a
cache, the scheduler has a similar function. Expose the function used
by the scheduler and make the block layer use it, thereby removing the
block layers usage of CONFIG_SCHED* and topology bits.Signed-off-by: Peter Zijlstra
Acked-by: Jens Axboe
Link: http://lkml.kernel.org/r/1327579450.2446.95.camel@twins
19 Jan, 2012
2 commits
-
Vivek reported a kernel crash:
[ 94.217015] BUG: unable to handle kernel NULL pointer dereference at 000000000000001c
[ 94.218004] IP: [] kmem_cache_free+0x5e/0x200
[ 94.218004] PGD 13abda067 PUD 137d52067 PMD 0
[ 94.218004] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 94.218004] CPU 0
[ 94.218004] Modules linked in: [last unloaded: scsi_wait_scan]
[ 94.218004]
[ 94.218004] Pid: 0, comm: swapper/0 Not tainted 3.2.0+ #16 Hewlett-Packard HP xw6600 Workstation/0A9Ch
[ 94.218004] RIP: 0010:[] [] kmem_cache_free+0x5e/0x200
[ 94.218004] RSP: 0018:ffff88013fc03de0 EFLAGS: 00010006
[ 94.218004] RAX: ffffffff81e0d020 RBX: ffff880138b3c680 RCX: 00000001801c001b
[ 94.218004] RDX: 00000000003aac1d RSI: ffff880138b3c680 RDI: ffffffff81142fae
[ 94.218004] RBP: ffff88013fc03e10 R08: ffff880137830238 R09: 0000000000000001
[ 94.218004] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[ 94.218004] R13: ffffea0004e2cf00 R14: ffffffff812f6eb6 R15: 0000000000000246
[ 94.218004] FS: 0000000000000000(0000) GS:ffff88013fc00000(0000) knlGS:0000000000000000
[ 94.218004] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 94.218004] CR2: 000000000000001c CR3: 00000001395ab000 CR4: 00000000000006f0
[ 94.218004] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 94.218004] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 94.218004] Process swapper/0 (pid: 0, threadinfo ffffffff81e00000, task ffffffff81e0d020)
[ 94.218004] Stack:
[ 94.218004] 0000000000000102 ffff88013fc0db20 ffffffff81e22700 ffff880139500f00
[ 94.218004] 0000000000000001 000000000000000a ffff88013fc03e20 ffffffff812f6eb6
[ 94.218004] ffff88013fc03e90 ffffffff810c8da2 ffffffff81e01fd8 ffff880137830240
[ 94.218004] Call Trace:
[ 94.218004]
[ 94.218004] [] icq_free_icq_rcu+0x16/0x20
[ 94.218004] [] __rcu_process_callbacks+0x1c2/0x420
[ 94.218004] [] rcu_process_callbacks+0x38/0x250
[ 94.218004] [] __do_softirq+0xce/0x3e0
[ 94.218004] [] ? clockevents_program_event+0x74/0x100
[ 94.218004] [] ? tick_program_event+0x24/0x30
[ 94.218004] [] call_softirq+0x1c/0x30
[ 94.218004] [] do_softirq+0x8d/0xc0
[ 94.218004] [] irq_exit+0xae/0xe0
[ 94.218004] [] smp_apic_timer_interrupt+0x6e/0x99
[ 94.218004] [] apic_timer_interrupt+0x70/0x80Once a queue is quiesced, it's not supposed to have any elvpriv data or
icq's, and elevator switching depends on that. Request alloc path
followed the rule for elvpriv data but forgot apply it to icq's
leading to the following crash during elevator switch. Fix it by not
allocating icq's if ELVPRIV is not set for the request.Reported-by: Vivek Goyal
Tested-by: Vivek Goyal
Signed-off-by: Shaohua Li
Acked-by: Tejun Heo
Signed-off-by: Jens Axboe -
cfq_slice_expired will change saved_workload_slice. It should be called
first so saved_workload_slice is correctly set to 0 after workload type
is changed.
This fixes the code order changed by 54b466e44b1c7.Tested-by: Tetsuo Handa
Signed-off-by: Shaohua Li
Signed-off-by: Jens Axboe
18 Jan, 2012
1 commit
-
With the changes in life time management between the cfq IO contexts
and the cfq queues, we now risk having cfqd->active_queue being
freed when cfq_slice_expired() is being called. cfq_preempt_queue()
caches this queue and uses it after calling said function, causing
a use-after-free condition. This triggers the following oops,
when cfqq_type() attempts to dereference it:BUG: unable to handle kernel paging request at ffff8800746c4f0c
IP: [] cfqq_type+0xb/0x20
PGD 18d4063 PUD 1fe15067 PMD 1ffb9067 PTE 80000000746c4160
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
CPU 3
Modules linked in:Pid: 1, comm: init Not tainted 3.2.0-josef+ #367 Bochs Bochs
RIP: 0010:[] [] cfqq_type+0xb/0x20
RSP: 0018:ffff880079c11778 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff880076f3df08 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffff880074271888 RDI: ffff8800746c4f08
RBP: ffff880079c11778 R08: 0000000000000078 R09: 0000000000000001
R10: 09f911029d74e35b R11: 09f911029d74e35b R12: ffff880076f337f0
R13: ffff8800746c4f08 R14: ffff8800746c4f08 R15: 0000000000000002
FS: 00007f62fd44f700(0000) GS:ffff88007cd80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8800746c4f0c CR3: 0000000076c21000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process init (pid: 1, threadinfo ffff880079c10000, task ffff880079c0a040)
Stack:
ffff880079c117c8 ffffffff812683d8 ffff880079c117a8 ffffffff8125de43
ffff8800744fcf48 ffff880074b43e98 ffff8800770c8828 ffff880074b43e98
0000000000000003 0000000000000000 ffff880079c117f8 ffffffff81254149
Call Trace:
[] cfq_insert_request+0x3f5/0x47c
[] ? blk_recount_segments+0x20/0x31
[] __elv_add_request+0x1ca/0x200
[] blk_queue_bio+0x2ef/0x312
[] generic_make_request+0x9f/0xe0
[] submit_bio+0xbf/0xca
[] submit_bh+0xdf/0xfe
[] ext3_bread+0x50/0x99
[] dx_probe+0x38/0x291
[] ext3_dx_find_entry+0x58/0x219
[] ext3_find_entry+0xb0/0x406
[] ? cache_alloc_debugcheck_after.isra.46+0x14d/0x1a0
[] ? kmem_cache_alloc+0xef/0x191
[] ext3_lookup+0x39/0xe1
[] d_alloc_and_lookup+0x45/0x6c
[] do_lookup+0x1e4/0x2f5
[] link_path_walk+0x1a4/0x6ef
[] path_lookupat+0x59/0x5ea
[] ? __strncpy_from_user+0x30/0x5a
[] do_path_lookup+0x23/0x59
[] user_path_at_empty+0x53/0x99
[] ? remove_wait_queue+0x51/0x56
[] user_path_at+0x11/0x13
[] vfs_fstatat+0x3a/0x64
[] vfs_stat+0x1b/0x1d
[] sys_newstat+0x1a/0x33
[] ? task_stopped_code+0x42/0x42
[] system_call_fastpath+0x16/0x1b
Code: 89 e6 48 89 c7 e8 fa ca fe ff 85 c0 74 06 4c 89 2b 41 b6 01 5b 44 89 f0 41 5c 41 5d 41 5e 5d c3 55 48 89 e5 66 66 66 66 90 31 c0 57 04 f6 c6 01 74 0b 83 e2 20 83 fa 01 19 c0 83 c0 02 5d c3
RIP [] cfqq_type+0xb/0x20
RSP
CR2: ffff8800746c4f0cGet rid of the caching of cfqd->active_queue, and reorder the
check so that it happens before we expire the active queue.Thanks to Tejun for pin pointing the error location.
Reported-by: Chris Mason
Tested-by: Chris Mason
Signed-off-by: Jens Axboe
16 Jan, 2012
1 commit
-
* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits)
Revert "block: recursive merge requests"
block: Stop using macro stubs for the bio data integrity calls
blockdev: convert some macros to static inlines
fs: remove unneeded plug in mpage_readpages()
block: Add BLKROTATIONAL ioctl
block: Introduce blk_set_stacking_limits function
block: remove WARN_ON_ONCE() in exit_io_context()
block: an exiting task should be allowed to create io_context
block: ioc_cgroup_changed() needs to be exported
block: recursive merge requests
block, cfq: fix empty queue crash caused by request merge
block, cfq: move icq creation and rq->elv.icq association to block core
block, cfq: restructure io_cq creation path for io_context interface cleanup
block, cfq: move io_cq exit/release to blk-ioc.c
block, cfq: move icq cache management to block core
block, cfq: move io_cq lookup to blk-ioc.c
block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq
block, cfq: reorganize cfq_io_context into generic and cfq specific parts
block: remove elevator_queue->ops
block: reorder elevator switch sequence
...Fix up conflicts in:
- block/blk-cgroup.c
Switch from can_attach_task to can_attach
- block/cfq-iosched.c
conflict with now removed cic index changes (we now use q->id instead)
15 Jan, 2012
3 commits
-
This reverts commit 274193224cdabd687d804a26e0150bb20f2dd52c.
We have some problems related to selection of empty queues
that need to be resolved, evidence so far points to the
recursive merge logic making either being the cause or at
least the accelerator for this. So revert it for now, until
we figure this out.Signed-off-by: Jens Axboe
-
Linux allows executing the SG_IO ioctl on a partition or LVM volume, and
will pass the command to the underlying block device. This is
well-known, but it is also a large security problem when (via Unix
permissions, ACLs, SELinux or a combination thereof) a program or user
needs to be granted access only to part of the disk.This patch lets partitions forward a small set of harmless ioctls;
others are logged with printk so that we can see which ioctls are
actually sent. In my tests only CDROM_GET_CAPABILITY actually occurred.
Of course it was being sent to a (partition on a) hard disk, so it would
have failed with ENOTTY and the patch isn't changing anything in
practice. Still, I'm treating it specially to avoid spamming the logs.In principle, this restriction should include programs running with
CAP_SYS_RAWIO. If for example I let a program access /dev/sda2 and
/dev/sdb, it still should not be able to read/write outside the
boundaries of /dev/sda2 independent of the capabilities. However, for
now programs with CAP_SYS_RAWIO will still be allowed to send the
ioctls. Their actions will still be logged.This patch does not affect the non-libata IDE driver. That driver
however already tests for bd != bd->bd_contains before issuing some
ioctl; it could be restricted further to forbid these ioctls even for
programs running with CAP_SYS_ADMIN/CAP_SYS_RAWIO.Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe
Cc: James Bottomley
Signed-off-by: Paolo Bonzini
[ Make it also print the command name when warning - Linus ]
Signed-off-by: Linus Torvalds -
Introduce a wrapper around scsi_cmd_ioctl that takes a block device.
The function will then be enhanced to detect partition block devices
and, in that case, subject the ioctls to whitelisting.Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe
Cc: James Bottomley
Signed-off-by: Paolo Bonzini
Signed-off-by: Linus Torvalds
11 Jan, 2012
2 commits
-
Introduce an ioctl which permits applications to query whether a block
device is rotational.Signed-off-by: Martin K. Petersen
Signed-off-by: Jens Axboe -
Stacking driver queue limits are typically bounded exclusively by the
capabilities of the low level devices, not by the stacking driver
itself.This patch introduces blk_set_stacking_limits() which has more liberal
metrics than the default queue limits function. This allows us to
inherit topology parameters from bottom devices without manually
tweaking the default limits in each driver prior to calling the stacking
function.Since there is now a clear distinction between stacking and low-level
devices, blk_set_default_limits() has been modified to carry the more
conservative values that we used to manually set in
blk_queue_make_request().Signed-off-by: Martin K. Petersen
Acked-by: Mike Snitzer
Signed-off-by: Jens Axboe
