Shaohua Li 5596d0d591 sched: always use blk_schedule_flush_plug in io_schedule_out ... block plug callback could sleep, so we introduce a parameter 'from_schedule' and corresponding drivers can use it to destinguish a schedule plug flush or a plug finish. Unfortunately io_schedule_out still uses blk_flush_plug(). This causes below output (Note, I added a might_sleep() in raid1_unplug to make it trigger faster, but the whole thing doesn't matter if I add might_sleep). In raid1/10, this can cause deadlock. This patch makes io_schedule_out always uses blk_schedule_flush_plug. This should only impact drivers (as far as I know, raid 1/10) which are sensitive to the 'from_schedule' parameter. [ 370.817949] ------------[ cut here ]------------ [ 370.817960] WARNING: CPU: 7 PID: 145 at ../kernel/sched/core.c:7306 __might_sleep+0x7f/0x90() [ 370.817969] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81092fcf>] prepare_to_wait+0x2f/0x90 [ 370.817971] Modules linked in: raid1 [ 370.817976] CPU: 7 PID: 145 Comm: kworker/u16:9 Tainted: G W 4.0.0+ #361 [ 370.817977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014 [ 370.817983] Workqueue: writeback bdi_writeback_workfn (flush-9:1) [ 370.817985] ffffffff81cd83be ffff8800ba8cb298 ffffffff819dd7af 0000000000000001 [ 370.817988] ffff8800ba8cb2e8 ffff8800ba8cb2d8 ffffffff81051afc ffff8800ba8cb2c8 [ 370.817990] ffffffffa00061a8 000000000000041e 0000000000000000 ffff8800ba8cba28 [ 370.817993] Call Trace: [ 370.817999] [<ffffffff819dd7af>] dump_stack+0x4f/0x7b [ 370.818002] [<ffffffff81051afc>] warn_slowpath_common+0x8c/0xd0 [ 370.818004] [<ffffffff81051b86>] warn_slowpath_fmt+0x46/0x50 [ 370.818006] [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90 [ 370.818008] [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90 [ 370.818010] [<ffffffff810776ef>] __might_sleep+0x7f/0x90 [ 370.818014] [<ffffffffa0000c03>] raid1_unplug+0xd3/0x170 [raid1] [ 370.818024] [<ffffffff81421d9a>] blk_flush_plug_list+0x8a/0x1e0 [ 370.818028] [<ffffffff819e3550>] ? bit_wait+0x50/0x50 [ 370.818031] [<ffffffff819e21b0>] io_schedule_timeout+0x130/0x140 [ 370.818033] [<ffffffff819e3586>] bit_wait_io+0x36/0x50 [ 370.818034] [<ffffffff819e31b5>] __wait_on_bit+0x65/0x90 [ 370.818041] [<ffffffff8125b67c>] ? ext4_read_block_bitmap_nowait+0xbc/0x630 [ 370.818043] [<ffffffff819e3550>] ? bit_wait+0x50/0x50 [ 370.818045] [<ffffffff819e3302>] out_of_line_wait_on_bit+0x72/0x80 [ 370.818047] [<ffffffff810935e0>] ? autoremove_wake_function+0x40/0x40 [ 370.818050] [<ffffffff811de744>] __wait_on_buffer+0x44/0x50 [ 370.818053] [<ffffffff8125ae80>] ext4_wait_block_bitmap+0xe0/0xf0 [ 370.818058] [<ffffffff812975d6>] ext4_mb_init_cache+0x206/0x790 [ 370.818062] [<ffffffff8114bc6c>] ? lru_cache_add+0x1c/0x50 [ 370.818064] [<ffffffff81297c7e>] ext4_mb_init_group+0x11e/0x200 [ 370.818066] [<ffffffff81298231>] ext4_mb_load_buddy+0x341/0x360 [ 370.818068] [<ffffffff8129a1a3>] ext4_mb_find_by_goal+0x93/0x2f0 [ 370.818070] [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818072] [<ffffffff8129ab67>] ext4_mb_regular_allocator+0x67/0x460 [ 370.818074] [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818076] [<ffffffff8129ca4b>] ext4_mb_new_blocks+0x4cb/0x620 [ 370.818079] [<ffffffff81290956>] ext4_ext_map_blocks+0x4c6/0x14d0 [ 370.818081] [<ffffffff812a4d4e>] ? ext4_es_lookup_extent+0x4e/0x290 [ 370.818085] [<ffffffff8126399d>] ext4_map_blocks+0x14d/0x4f0 [ 370.818088] [<ffffffff81266fbd>] ext4_writepages+0x76d/0xe50 [ 370.818094] [<ffffffff81149691>] do_writepages+0x21/0x50 [ 370.818097] [<ffffffff811d5c00>] __writeback_single_inode+0x60/0x490 [ 370.818099] [<ffffffff811d630a>] writeback_sb_inodes+0x2da/0x590 [ 370.818103] [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50 [ 370.818105] [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50 [ 370.818107] [<ffffffff811d665f>] __writeback_inodes_wb+0x9f/0xd0 [ 370.818109] [<ffffffff811d69db>] wb_writeback+0x34b/0x3c0 [ 370.818111] [<ffffffff811d70df>] bdi_writeback_workfn+0x23f/0x550 [ 370.818116] [<ffffffff8106bbd8>] process_one_work+0x1c8/0x570 [ 370.818117] [<ffffffff8106bb5b>] ? process_one_work+0x14b/0x570 [ 370.818119] [<ffffffff8106c09b>] worker_thread+0x11b/0x470 [ 370.818121] [<ffffffff8106bf80>] ? process_one_work+0x570/0x570 [ 370.818124] [<ffffffff81071868>] kthread+0xf8/0x110 [ 370.818126] [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210 [ 370.818129] [<ffffffff819e9322>] ret_from_fork+0x42/0x70 [ 370.818131] [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210 [ 370.818132] ---[ end trace 7b4deb71e68b6605 ]--- V2: don't change ->in_iowait Cc: NeilBrown <neilb@suse.de> Signed-off-by: Shaohua Li <shli@fb.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>		2015-05-08 14:17:15 -06:00
..
auto_group.c	sched/autogroup: Fix failure to set cpu.rt_runtime_us	2015-02-18 16:17:20 +01:00
auto_group.h	Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled"	2012-12-11 10:23:45 +01:00
clock.c	kernel/sched/clock.c: add another clock for use with the soft lockup watchdog	2015-02-12 18:54:13 -08:00
completion.c	sched/completion: Serialize completion_done() with complete()	2015-02-18 14:27:40 +01:00
core.c	sched: always use blk_schedule_flush_plug in io_schedule_out	2015-05-08 14:17:15 -06:00
cpuacct.c	cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes	2014-07-15 11:05:09 -04:00
cpuacct.h	sched/cpuacct: Initialize root cpuacct earlier	2013-04-10 13:54:20 +02:00
cpudeadline.c	sched/deadline: Remove cpu_active_mask from cpudl_find()	2015-02-04 07:52:29 +01:00
cpudeadline.h	sched/deadline: Modify cpudl::free_cpus to reflect rd->online	2015-01-30 19:39:16 +01:00
cpupri.c	Merge commit '3cf2f34' into sched/core, to fix build error	2014-06-12 13:46:37 +02:00
cpupri.h	sched/cpupri: Remove unnecessary definitions in cpupri.h	2014-11-16 10:58:59 +01:00
cputime.c	sched, time: Fix build error with 64 bit cputime_t on 32 bit systems	2014-10-03 05:46:55 +02:00
deadline.c	sched/deadline: Support DL task migration during CPU hotplug	2015-04-02 17:42:57 +02:00
debug.c	sched: Track group sched_entity usage contributions	2015-03-27 09:35:58 +01:00
fair.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-04-13 10:47:34 -07:00
features.h	sched/rt: Use IPI to trigger RT task push migration instead of pulling	2015-03-23 10:55:22 +01:00
idle.c	cpuidle: Run tick_broadcast_exit() with disabled interrupts	2015-04-29 15:19:21 +02:00
idle_task.c	sched: Provide update_curr callbacks for stop/idle scheduling classes	2014-11-23 14:14:40 -08:00
Makefile	ftrace: allow architectures to specify ftrace compile options	2015-01-29 09:19:19 +01:00
proc.c	cpuidle: menu: Lookup CPU runqueues less	2014-08-06 21:17:45 +02:00
rt.c	sched/core: Remove unused argument from init_[rt|dl]_rq()	2015-04-02 17:42:55 +02:00
sched.h	sched/core: Remove unused argument from init_[rt|dl]_rq()	2015-04-02 17:42:55 +02:00
stats.c	sched: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:37 -08:00
stats.h	sched: Micro-optimize by dropping unnecessary task_rq() calls	2013-09-25 13:51:06 +02:00
stop_task.c	sched: Provide update_curr callbacks for stop/idle scheduling classes	2014-11-23 14:14:40 -08:00
wait.c	sched/wait: Fix a kthread race with wait_woken()	2014-11-04 07:17:44 +01:00