jiangyiwen
2016-Jan-25 02:52 UTC
[Ocfs2-devel] [PATCH] ocfs2: use spinlock irqsave for downconvert lock in ocfs2_osb_dump()
commit a75e9ccabd92("ocfs2: use spinlock irqsave for downconvert
lock")
missed an unmodified place in ocfs2_osb_dump(), so it still exists
a deadlock scenario.
ocfs2_wake_downconvert_thread
ocfs2_rw_unlock
ocfs2_dio_end_io
dio_complete
.....
bio_endio
req_bio_endio
....
scsi_io_completion
blk_done_softirq
__do_softirq
do_softirq
irq_exit
do_IRQ
ocfs2_osb_dump
cat /sys/kernel/debug/ocfs2/${uuid}/fs_state
This patch will still use spin_lock_irqsave() replace spin_lock() to
solve this situation.
Signed-off-by: Yiwen Jiang <jiangyiwen at huawei.com>
Reviewed-by: Joseph Qi <joseph.qi at huawei.com>
---
fs/ocfs2/super.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 2de4c8a..0623710 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -236,6 +236,7 @@ static int ocfs2_osb_dump(struct ocfs2_super *osb, char
*buf, int len)
struct ocfs2_recovery_map *rm = osb->recovery_map;
struct ocfs2_orphan_scan *os = &osb->osb_orphan_scan;
int i, out = 0;
+ unsigned long flags;
out += snprintf(buf + out, len - out,
"%10s => Id: %-s Uuid: %-s Gen: 0x%X Label: %-s\n",
@@ -271,14 +272,14 @@ static int ocfs2_osb_dump(struct ocfs2_super *osb, char
*buf, int len)
cconn->cc_version.pv_minor);
}
- spin_lock(&osb->dc_task_lock);
+ spin_lock_irqsave(&osb->dc_task_lock, flags);
out += snprintf(buf + out, len - out,
"%10s => Pid: %d Count: %lu WakeSeq: %lu "
"WorkSeq: %lu\n", "DownCnvt",
(osb->dc_task ? task_pid_nr(osb->dc_task) : -1),
osb->blocked_lock_count, osb->dc_wake_sequence,
osb->dc_work_sequence);
- spin_unlock(&osb->dc_task_lock);
+ spin_unlock_irqrestore(&osb->dc_task_lock, flags);
spin_lock(&osb->osb_lock);
out += snprintf(buf + out, len - out, "%10s => Pid: %d Nodes:",
--
1.8.4.3