[PATCH] f2fs: fix conflict between atomic_write and truncate

[Hou Pengyang <houpengyang@huawei.com>]

In fsync_node_pages path, after locking the last_page for setting dirty,
we should check if the page has been truncated. Or there may be a mem leak,
as this dirty last_page will NOT be found in next page-cache travese.

This patch adds page->mapping checking, and will NOT rewrite the page if
it has been truncated.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
---
 fs/f2fs/node.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index c1bbfdc..78c5b50 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1410,6 +1410,11 @@ int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
 			"Retry to write fsync mark: ino=%u, idx=%lx",
 					ino, last_page->index);
 		lock_page(last_page);
+		if (unlikely(last_page->mapping != NODE_MAPPING(sbi))) {
+			unlock_page(last_page);
+			f2fs_put_page(last_page, 0);
+			goto out;
+		}
 		f2fs_wait_on_page_writeback(last_page, NODE, true);
 		set_page_dirty(last_page);
 		unlock_page(last_page);
-- 
2.10.1


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