Commit d3238691 authored Aug 31, 2017 by Chao Yu Committed by Jaegeuk Kim Sep 05, 2017

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: 5eba8c5d ("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>

parent edd748e6

fs/f2fs/segment.c

+21 −2

Original line number	Diff line number	Diff line
		@@ -558,8 +558,27 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
		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;

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