diff mbox series

ocfs2: fix potential soft lockup during fstrim

Message ID 20200927015815.14904-1-ghe@suse.com (mailing list archive)
State New, archived
Headers show
Series ocfs2: fix potential soft lockup during fstrim | expand

Commit Message

Gang He Sept. 27, 2020, 1:58 a.m. UTC
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 <ghe@suse.com>
---
 fs/ocfs2/alloc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Joseph Qi Sept. 27, 2020, 2:59 a.m. UTC | #1
On 2020/9/27 09:58, Gang He wrote:
> 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 <ghe@suse.com>

It makes sense.
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>

> ---
>  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;
>
diff mbox series

Patch

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;