1. 30 Nov, 2018 1 commit
    • Christoph Hellwig's avatar
      block: avoid extra bio reference for async O_DIRECT · 531724ab
      Christoph Hellwig authored
      The bio referencing has a trick that doesn't do any actual atomic
      inc/dec on the reference count until we have to elevator to > 1. For the
      async IO O_DIRECT case, we can't use the simple DIO variants, so we use
      __blkdev_direct_IO(). It always grabs an extra reference to the bio
      after allocation, which means we then enter the slower path of actually
      having to do atomic_inc/dec on the count.
      
      We don't need to do that for the async case, unless we end up going
      multi-bio, in which case we're already doing huge amounts of IO. For the
      smaller IO case (< BIO_MAX_PAGES), we can do without the extra ref.
      
      Based on an earlier patch (and commit log) from Jens Axboe.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      531724ab
  2. 29 Nov, 2018 10 commits
  3. 28 Nov, 2018 4 commits
    • Weiping Zhang's avatar
      block: add io timeout to sysfs · 65cd1d13
      Weiping Zhang authored
      Give a interface to adjust io timeout(ms) by device.
      Signed-off-by: default avatarWeiping Zhang <zhangweiping@didiglobal.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      65cd1d13
    • Yufen Yu's avatar
      block: use rcu_work instead of call_rcu to avoid sleep in softirq · 94a2c3a3
      Yufen Yu authored
      We recently got a stack by syzkaller like this:
      
      BUG: sleeping function called from invalid context at mm/slab.h:361
      in_atomic(): 1, irqs_disabled(): 0, pid: 6644, name: blkid
      INFO: lockdep is turned off.
      CPU: 1 PID: 6644 Comm: blkid Not tainted 4.4.163-514.55.6.9.x86_64+ #76
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
       0000000000000000 5ba6a6b879e50c00 ffff8801f6b07b10 ffffffff81cb2194
       0000000041b58ab3 ffffffff833c7745 ffffffff81cb2080 5ba6a6b879e50c00
       0000000000000000 0000000000000001 0000000000000004 0000000000000000
      Call Trace:
       <IRQ>  [<ffffffff81cb2194>] __dump_stack lib/dump_stack.c:15 [inline]
       <IRQ>  [<ffffffff81cb2194>] dump_stack+0x114/0x1a0 lib/dump_stack.c:51
       [<ffffffff8129a981>] ___might_sleep+0x291/0x490 kernel/sched/core.c:7675
       [<ffffffff8129ac33>] __might_sleep+0xb3/0x270 kernel/sched/core.c:7637
       [<ffffffff81794c13>] slab_pre_alloc_hook mm/slab.h:361 [inline]
       [<ffffffff81794c13>] slab_alloc_node mm/slub.c:2610 [inline]
       [<ffffffff81794c13>] slab_alloc mm/slub.c:2692 [inline]
       [<ffffffff81794c13>] kmem_cache_alloc_trace+0x2c3/0x5c0 mm/slub.c:2709
       [<ffffffff81cbe9a7>] kmalloc include/linux/slab.h:479 [inline]
       [<ffffffff81cbe9a7>] kzalloc include/linux/slab.h:623 [inline]
       [<ffffffff81cbe9a7>] kobject_uevent_env+0x2c7/0x1150 lib/kobject_uevent.c:227
       [<ffffffff81cbf84f>] kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:374
       [<ffffffff81cbb5b9>] kobject_cleanup lib/kobject.c:633 [inline]
       [<ffffffff81cbb5b9>] kobject_release+0x229/0x440 lib/kobject.c:675
       [<ffffffff81cbb0a2>] kref_sub include/linux/kref.h:73 [inline]
       [<ffffffff81cbb0a2>] kref_put include/linux/kref.h:98 [inline]
       [<ffffffff81cbb0a2>] kobject_put+0x72/0xd0 lib/kobject.c:692
       [<ffffffff8216f095>] put_device+0x25/0x30 drivers/base/core.c:1237
       [<ffffffff81c4cc34>] delete_partition_rcu_cb+0x1d4/0x2f0 block/partition-generic.c:232
       [<ffffffff813c08bc>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
       [<ffffffff813c08bc>] rcu_do_batch kernel/rcu/tree.c:2705 [inline]
       [<ffffffff813c08bc>] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline]
       [<ffffffff813c08bc>] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline]
       [<ffffffff813c08bc>] rcu_process_callbacks+0x59c/0x1c70 kernel/rcu/tree.c:2957
       [<ffffffff8120f509>] __do_softirq+0x299/0xe20 kernel/softirq.c:273
       [<ffffffff81210496>] invoke_softirq kernel/softirq.c:350 [inline]
       [<ffffffff81210496>] irq_exit+0x216/0x2c0 kernel/softirq.c:391
       [<ffffffff82c2cd7b>] exiting_irq arch/x86/include/asm/apic.h:652 [inline]
       [<ffffffff82c2cd7b>] smp_apic_timer_interrupt+0x8b/0xc0 arch/x86/kernel/apic/apic.c:926
       [<ffffffff82c2bc25>] apic_timer_interrupt+0xa5/0xb0 arch/x86/entry/entry_64.S:746
       <EOI>  [<ffffffff814cbf40>] ? audit_kill_trees+0x180/0x180
       [<ffffffff8187d2f7>] fd_install+0x57/0x80 fs/file.c:626
       [<ffffffff8180989e>] do_sys_open+0x45e/0x550 fs/open.c:1043
       [<ffffffff818099c2>] SYSC_open fs/open.c:1055 [inline]
       [<ffffffff818099c2>] SyS_open+0x32/0x40 fs/open.c:1050
       [<ffffffff82c299e1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
      
      In softirq context, we call rcu callback function delete_partition_rcu_cb(),
      which may allocate memory by kzalloc with GFP_KERNEL flag. If the
      allocation cannot be satisfied, it may sleep. However, That is not allowed
      in softirq contex.
      
      Although we found this problem on linux 4.4, the latest kernel version
      seems to have this problem as well. And it is very similar to the
      previous one:
      	https://lkml.org/lkml/2018/7/9/391
      
      Fix it by using RCU workqueue, which allows sleep.
      Reviewed-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
      Signed-off-by: default avatarYufen Yu <yuyufen@huawei.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      94a2c3a3
    • Jens Axboe's avatar
      blk-mq: fix failure to decrement plug count on single rq removal · 4711b573
      Jens Axboe authored
      If we yank a 'same_queue_rq' request off the plug list, we should
      also decrement the cached request count.
      
      Fixes: 5f0ed774 ("block: sum requests in the plug structure")
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      4711b573
    • Young Xiao's avatar
      sunvdc: Do not spin in an infinite loop when vio_ldc_send() returns EAGAIN · a11f6ca9
      Young Xiao authored
      __vdc_tx_trigger should only loop on EAGAIN a finite
      number of times.
      
      See commit adddc32d ("sunvnet: Do not spin in an
      infinite loop when vio_ldc_send() returns EAGAIN") for detail.
      Signed-off-by: default avatarYoung Xiao <YangX92@hotmail.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      a11f6ca9
  4. 26 Nov, 2018 10 commits
  5. 21 Nov, 2018 2 commits
  6. 20 Nov, 2018 6 commits
  7. 19 Nov, 2018 4 commits
  8. 18 Nov, 2018 3 commits