From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gang He Date: Sun, 27 Sep 2020 09:58:15 +0800 Subject: [Ocfs2-devel] [PATCH] ocfs2: fix potential soft lockup during fstrim Message-ID: <20200927015815.14904-1-ghe@suse.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: mark@fasheh.com, jlbec@evilplan.org, joseph.qi@linux.alibaba.com Cc: Gang He , linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com, akpm@linux-foundation.org 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. Signed-off-by: Gang He --- fs/ocfs2/alloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index 4c1b90442d6f..2cf9321919b5 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -7654,8 +7654,10 @@ int ocfs2_trim_mainbm(struct super_block *sb, struct fstrim_range *range) * 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; -- 2.21.0