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authorChao Yu <yuchao0@huawei.com>2017-08-21 22:53:45 +0800
committerJaegeuk Kim <jaegeuk@kernel.org>2017-08-29 10:02:55 -0700
commit6f890df0a7efe3181aceb5d8bcd4af7deb2abce5 (patch)
treece48d5d913e9f4c9712224f299a07e29dcffcef8 /fs
parent5f656541ff6e4f58b4ab5b4ae59badb97a9ff749 (diff)
downloadop-kernel-dev-6f890df0a7efe3181aceb5d8bcd4af7deb2abce5.zip
op-kernel-dev-6f890df0a7efe3181aceb5d8bcd4af7deb2abce5.tar.gz
f2fs: fix out-of-order execution in f2fs_issue_flush
In f2fs_issue_flush, due to out-of-order execution of CPU, wake_up can be called before we insert issue_list, result in long latency of wait_for_completion. Fix this by adding smp_mb() to force the order of related codes. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/f2fs/segment.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index e3922f9..be1c49b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -549,7 +549,10 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
atomic_inc(&fcc->issing_flush);
llist_add(&cmd.llnode, &fcc->issue_list);
- if (!fcc->dispatch_list)
+ /* update issue_list before we wake up issue_flush thread */
+ smp_mb();
+
+ if (waitqueue_active(&fcc->flush_wait_queue))
wake_up(&fcc->flush_wait_queue);
if (fcc->f2fs_issue_flush) {
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