f2fs: fix to wake up all sleeping flusher
In scenario of remount_ro vs flush, after flush_thread exits in
->remount_fs, flusher will only clean up golbal issue_list, but
without waking up flushers waiting on that list, result in hang
related user threads.
In order to fix this issue, this patch enables the flusher to
take charge of issue_flush thread: executes merged flush command,
and wake up all sleeping flushers.
Fixes: 5eba8c5d1fb3 ("f2fs: fix to access nullified flush_cmd_control pointer")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 7ac4e6b..372bc47 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -558,8 +558,27 @@
wait_for_completion(&cmd.wait);
atomic_dec(&fcc->issing_flush);
} else {
- llist_del_all(&fcc->issue_list);
- atomic_set(&fcc->issing_flush, 0);
+ struct llist_node *list;
+
+ list = llist_del_all(&fcc->issue_list);
+ if (!list) {
+ wait_for_completion(&cmd.wait);
+ atomic_dec(&fcc->issing_flush);
+ } else {
+ struct flush_cmd *tmp, *next;
+
+ ret = submit_flush_wait(sbi);
+
+ llist_for_each_entry_safe(tmp, next, list, llnode) {
+ if (tmp == &cmd) {
+ cmd.ret = ret;
+ atomic_dec(&fcc->issing_flush);
+ continue;
+ }
+ tmp->ret = ret;
+ complete(&tmp->wait);
+ }
+ }
}
return cmd.ret;