From 8dd71b25c56a707fd492035c03e20e91040eedcf Mon Sep 17 00:00:00 2001 From: Gang He Date: Tue, 13 Oct 2020 16:48:24 -0700 Subject: [PATCH] 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. Signed-off-by: Gang He Signed-off-by: Andrew Morton Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Link: https://lkml.kernel.org/r/20200927015815.14904-1-ghe@suse.com Signed-off-by: Linus Torvalds --- 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 32317ffb9e5c..78710788c237 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;