linux/block, branch v3.4.31

scsi: Silence unnecessary warnings about ioctl to partition

2012-12-03T19:47:11Z

commit 6d9359280753d2955f86d6411047516a9431eb51 upstream. Sometimes, warnings about ioctls to partition happen often enough that they form majority of the warnings in the kernel log and users complain. In some cases warnings are about ioctls such as SG_IO so it's not good to get rid of the warnings completely as they can ease debugging of userspace problems when ioctl is refused. Since I have seen warnings from lots of commands, including some proprietary userspace applications, I don't think disallowing the ioctls for processes with CAP_SYS_RAWIO will happen in the near future if ever. So lets just stop warning for processes with CAP_SYS_RAWIO for which ioctl is allowed. Acked-by: Paolo Bonzini CC: Paolo Bonzini CC: James Bottomley Signed-off-by: Jan Kara Signed-off-by: Jens Axboe Cc: satoru takeuchi Signed-off-by: Greg Kroah-Hartman

block: fix request_queue->flags initialization

2012-10-21T16:27:59Z

commit 60ea8226cbd5c8301f9a39edc574ddabcb8150e0 upstream. A queue newly allocated with blk_alloc_queue_node() has only QUEUE_FLAG_BYPASS set. For request-based drivers, blk_init_allocated_queue() is called and q->queue_flags is overwritten with QUEUE_FLAG_DEFAULT which doesn't include BYPASS even though the initial bypass is still in effect. In blk_init_allocated_queue(), or QUEUE_FLAG_DEFAULT to q->queue_flags instead of overwriting. Signed-off-by: Tejun Heo Acked-by: Vivek Goyal Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: fix buffer overflow when printing partition UUIDs

2012-05-15T06:22:04Z

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+0x13/0x13 Increase 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

Merge branch 'for-3.4/core' of git://git.kernel.dk/linux-block

2012-04-14T01:07:19Z

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

block: make auto block plug flush threshold per-disk based

2012-04-06T17:37:47Z

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

block: Make cfq_target_latency tunable through sysfs.

2012-04-01T21:33:39Z

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

block: use lockdep_assert_held for queue locking

2012-03-30T10:33:28Z

Instead of an ugly open coded variant. Cc: axboe@kernel.dk Signed-off-by: Andi Kleen Signed-off-by: Jens Axboe

block: blk_alloc_queue_node(): use caller's GFP flags instead of GFP_KERNEL

2012-03-23T08:58:54Z

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

Merge branch 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2012-03-21T01:11:21Z

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()

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-03-20T17:31:44Z

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 ...