2018-05-03 07:47:50

by Yunlong Song

Subject: [PATCH] f2fs: fix the way to wake up issue_flush thread

Commit 6f890df0 ("f2fs: fix out-of-order execution in f2fs_issue_flush")
uses waitqueue_active to wake up issue_flush thread, but there is no
wait entry to wake in this queue, so change it back to use the original
fcc->dispatch_list to wake up issue_flush thread.

Signed-off-by: Yunlong Song <[email protected]>
---
fs/f2fs/segment.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 503a98a..5aa5ee4e 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -612,7 +612,7 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi, nid_t ino)
/* update issue_list before we wake up issue_flush thread */
smp_mb();

- if (waitqueue_active(&fcc->flush_wait_queue))
+ if (!fcc->dispatch_list)
wake_up(&fcc->flush_wait_queue);

if (fcc->f2fs_issue_flush) {
--
1.8.5.2

2018-05-03 08:00:39

by Yunlong Song

Subject: Re: [PATCH] f2fs: fix the way to wake up issue_flush thread

Please avoid this patch, I make a mistake.

On 2018/5/3 15:45, Yunlong Song wrote:
> Commit 6f890df0 ("f2fs: fix out-of-order execution in f2fs_issue_flush")
> uses waitqueue_active to wake up issue_flush thread, but there is no
> wait entry to wake in this queue, so change it back to use the original
> fcc->dispatch_list to wake up issue_flush thread.
>
> Signed-off-by: Yunlong Song <[email protected]>
> ---
> fs/f2fs/segment.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 503a98a..5aa5ee4e 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -612,7 +612,7 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi, nid_t ino)
> /* update issue_list before we wake up issue_flush thread */
> smp_mb();
>
> - if (waitqueue_active(&fcc->flush_wait_queue))
> + if (!fcc->dispatch_list)
> wake_up(&fcc->flush_wait_queue);
>
> if (fcc->f2fs_issue_flush) {

--
Thanks,
Yunlong Song