[PATCH 1/2] f2fs: fix to fetch ino via ino_of_node() under cache lock

[Chao Yu <chao@kernel.org>]

From: Chao Yu <chao@kernel.org>

In f2fs_writeback_node_caches(), it's better to fetch ino via ino_of_node()
under cache lock, otherwise, node cache content may become stale after cache
is unlocked due to racing w/ truncation.

Commit 493b9dc8b52c ("f2fs: cache: use node cache") fixes similar issue in
f2fs_flush_inline_data() introduced in commit 34c061ad85a2 ("f2fs: Avoid double
lock for cp_rwsem during checkpoint").

Cc: stable@kernel.org
Fixes: 2049d4fcb057 ("f2fs: avoid multiple node page writes due to inline_data")
Signed-off-by: Chao Yu <chao@kernel.org>
---
 fs/f2fs/node.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 424e95ca5878..44f94000d452 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -2195,9 +2195,11 @@ int f2fs_writeback_node_caches(struct f2fs_sb_info *sbi, long nr_to_write,
 
 			/* flush inline_data */
 			if (f2fs_cache_test_inline(entry)) {
+				nid_t ino = ino_of_node(sbi, entry);
+
 				f2fs_cache_clear_inline(entry);
 				f2fs_unlock_cache(entry);
-				flush_inline_data(sbi, ino_of_node(sbi, entry));
+				flush_inline_data(sbi, ino);
 				goto lock_node;
 			}
 
-- 
2.49.0