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| author | Chao Yu <yuchao0@huawei.com> | 2017-08-21 22:53:45 +0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-10-04 15:35:21 +0200 |
| commit | f19d913de6d5f4a1b97c3b8a6459207439fb9396 (patch) | |
| tree | b250470f20fa6c42c5fb1af940cdd7eb37795dfd | |
| parent | f34bdace069ba7781ea86993ffb3c3a71404c48d (diff) | |
| download | android_kernel_m2note-f19d913de6d5f4a1b97c3b8a6459207439fb9396.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>
| -rw-r--r-- | fs/f2fs/segment.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 9e749214d..fe9232920 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -587,7 +587,10 @@ 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) { |