linux-kernel - [PATCH 1/2] f2fs: fix to commit bio cache after flushing node pages

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Date:   Tue, 27 Sep 2016 00:09:52 +0800
From:   Chao Yu <chao@...nel.org>
To:     jaegeuk@...nel.org
Cc:     linux-f2fs-devel@...ts.sourceforge.net,
        linux-kernel@...r.kernel.org, Chao Yu <yuchao0@...wei.com>
Subject: [PATCH 1/2] f2fs: fix to commit bio cache after flushing node pages

From: Chao Yu <yuchao0@...wei.com>

In sync_node_pages, we won't check and commit last merged pages in private
bio cache of f2fs, as these pages were taged as writeback, someone who is
waiting for writebacking of the page will be blocked until the cache was
committed by someone else.

We need to commit node type bio cache to avoid potential deadlock or long
delay of waiting writeback.

Signed-off-by: Chao Yu <yuchao0@...wei.com>
---
 fs/f2fs/node.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 9faddcd..f73f774 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1416,6 +1416,7 @@ int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc)
 	struct pagevec pvec;
 	int step = 0;
 	int nwritten = 0;
+	int ret = 0;
 
 	pagevec_init(&pvec, 0);
 
@@ -1436,7 +1437,8 @@ next_step:
 
 			if (unlikely(f2fs_cp_error(sbi))) {
 				pagevec_release(&pvec);
-				return -EIO;
+				ret = -EIO;
+				goto out;
 			}
 
 			/*
@@ -1487,6 +1489,8 @@ continue_unlock:
 
 			if (NODE_MAPPING(sbi)->a_ops->writepage(page, wbc))
 				unlock_page(page);
+			else
+				nwritten++;
 
 			if (--wbc->nr_to_write == 0)
 				break;
@@ -1504,7 +1508,10 @@ continue_unlock:
 		step++;
 		goto next_step;
 	}
-	return nwritten;
+out:
+	if (nwritten)
+		f2fs_submit_merged_bio(sbi, NODE, WRITE);
+	return ret;
 }
 
 int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
-- 
2.7.2