[PATCH 2/2] block: Make I/O timeout failure injection support again task-independent

From: Bart Van Assche
Date: Tue Aug 22 2017 - 12:54:14 EST


Commit e41d58185f14 made all faults that are triggered from task
context, including I/O timeouts, dependent on the failure
injection settings for that task. Make it again possible to inject
I/O timeout failures independent of task context. An example for a
fault injection for which this patch makes a difference (from a VM
booted with the 'threadirqs' command line parameter):

FAULT_INJECTION: forcing a failure. name fail_io_timeout, interval 1, probability 100, space 0, times 1
CPU: 6 PID: 1253 Comm: irq/36-skd0-msi Not tainted 4.13.0-rc2-dbg+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014
Call Trace:
dump_stack+0x8e/0xcd
should_fail+0x154/0x160
blk_should_fake_timeout+0x27/0x30
blk_mq_complete_request+0x11/0x30
skd_end_request+0x32/0xc0 [skd]
skd_isr_completion_posted.isra.30+0x14a/0x400 [skd]
skd_comp_q+0x40/0xb0 [skd]
irq_forced_thread_fn+0x2a/0x70
irq_thread+0x144/0x1a0
kthread+0x125/0x140
ret_from_fork+0x2a/0x40

Fixes: commit e41d58185f14 ("fault-inject: support systematic fault injection")
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
block/blk-timeout.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 17ec83bb0900..2e92b20b125f 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -11,7 +11,7 @@

#ifdef CONFIG_FAIL_IO_TIMEOUT

-static DECLARE_FAULT_ATTR(fail_io_timeout);
+static DECLARE_GLOBAL_FAULT_ATTR(fail_io_timeout);

static int __init setup_fail_io_timeout(char *str)
{
--
2.14.0