Commit 6afae633 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
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f2fs: wait discard IO completion without cmd_lock held 



Wait discard IO completion outside cmd_lock to avoid long latency
of holding cmd_lock in IO busy scenario.

Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent e31b9821

fs/f2fs/segment.c

+20 −3
Original line number Diff line number Diff line
@@ -997,17 +997,34 @@ static void __wait_discard_cmd(struct f2fs_sb_info *sbi, bool wait_cond) 
	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;

	struct list_head *wait_list = &(dcc->wait_list);

	struct discard_cmd *dc, *tmp;

	bool need_wait;



next:

	need_wait = false;



	mutex_lock(&dcc->cmd_lock);

	list_for_each_entry_safe(dc, tmp, wait_list, list) {

		if (!wait_cond || dc->state == D_DONE) {

			if (dc->ref)

				continue;

		if (!wait_cond || (dc->state == D_DONE && !dc->ref)) {

			wait_for_completion_io(&dc->wait);

			__remove_discard_cmd(sbi, dc);

		} else {

			dc->ref++;

			need_wait = true;

			break;

		}

	}

	mutex_unlock(&dcc->cmd_lock);



	if (need_wait) {

		wait_for_completion_io(&dc->wait);

		mutex_lock(&dcc->cmd_lock);

		f2fs_bug_on(sbi, dc->state != D_DONE);

		dc->ref--;

		if (!dc->ref)

			__remove_discard_cmd(sbi, dc);

		mutex_unlock(&dcc->cmd_lock);

		goto next;

	}

}



/* This should be covered by global mutex, &sit_i->sentry_lock */