diff mbox series

[016/181] ocfs2: fix potential soft lockup during fstrim

Message ID 20201013234824.U65EF3eQo%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [001/181] compiler-clang: add build check for clang 10.0.1 | expand

Commit Message

Andrew Morton Oct. 13, 2020, 11:48 p.m. UTC 
From: Gang He <ghe@suse.com>
Subject: ocfs2: fix potential soft lockup during fstrim

When we discard unused blocks on a mounted ocfs2 filesystem, fstrim
handles each block goup with locking/unlocking global bitmap meta-file
repeatedly. we should let fstrim thread take a break(if need) between
unlock and lock, this will avoid the potential soft lockup problem,
and also gives the upper applications more IO opportunities, these
applications are not blocked for too long at writing files.

Link: https://lkml.kernel.org/r/20200927015815.14904-1-ghe@suse.com
Signed-off-by: Gang He <ghe@suse.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ocfs2/alloc.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

--- a/fs/ocfs2/alloc.c~ocfs2-fix-potential-soft-lockup-during-fstrim
+++ a/fs/ocfs2/alloc.c
@@ -7654,8 +7654,10 @@  out_mutex:
 	 * main_bm related locks for avoiding the current IO starve, then go to
 	 * trim the next group
 	 */
-	if (ret >= 0 && group <= last_group)
+	if (ret >= 0 && group <= last_group) {
+		cond_resched();
 		goto next_group;
+	}
 out:
 	range->len = trimmed * sb->s_blocksize;
 	return ret;