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| author | Guoqing Jiang <gqjiang@suse.com> | 2017-09-25 09:47:50 +0200 |
|---|---|---|
| committer | David Teigland <teigland@redhat.com> | 2017-09-25 19:48:10 +0200 |
| commit | 9e1b0211c5dd4acbd21a8ec1b86fc38a497a4656 (patch) | |
| tree | 3ed03ed06aa2ed4439017f79a81c0388c88b3728 | |
| parent | DLM: fix NULL pointer dereference in send_to_sock() (diff) | |
| download | linux-9e1b0211c5dd4acbd21a8ec1b86fc38a497a4656.tar.xz linux-9e1b0211c5dd4acbd21a8ec1b86fc38a497a4656.zip | |
dlm: recheck kthread_should_stop() before schedule()
Call schedule() here could make the thread miss wake
up from kthread_stop(), so it is better to recheck
kthread_should_stop() before call schedule(), a symptom
happened when I run indefinite test (which mostly created
clustered raid1, assemble it in other nodes, then stop
them) of clustered raid.
$ ps aux|grep md|grep D
root 4211 0.0 0.0 19760 2220 ? Ds 02:58 0:00 mdadm -Ssq
$ cat /proc/4211/stack
kthread_stop+0x4d/0x150
dlm_recoverd_stop+0x15/0x20 [dlm]
dlm_release_lockspace+0x2ab/0x460 [dlm]
leave+0xbf/0x150 [md_cluster]
md_cluster_stop+0x18/0x30 [md_mod]
bitmap_free+0x12e/0x140 [md_mod]
bitmap_destroy+0x7f/0x90 [md_mod]
__md_stop+0x21/0xa0 [md_mod]
do_md_stop+0x15f/0x5c0 [md_mod]
md_ioctl+0xa65/0x18a0 [md_mod]
blkdev_ioctl+0x49e/0x8d0
block_ioctl+0x41/0x50
do_vfs_ioctl+0x96/0x5b0
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x1e/0xad
This maybe not resolve the issue completely since the
KTHREAD_SHOULD_STOP flag could be set between "break"
and "schedule", but at least the chance for the symptom
happen could be reduce a lot (The indefinite test runs
more than 20 hours without problem and it happens easily
without the change).
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>
| -rw-r--r-- | fs/dlm/recoverd.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c index d2ad1cab0f05..6f4e1d42d733 100644 --- a/fs/dlm/recoverd.c +++ b/fs/dlm/recoverd.c @@ -299,8 +299,11 @@ static int dlm_recoverd(void *arg) break; } if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) && - !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) + !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) { + if (kthread_should_stop()) + break; schedule(); + } set_current_state(TASK_RUNNING); if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) { |