[PATCH AUTOSEL for 4.9 085/219] f2fs: relax node version check for victim data in gc

Sasha Levin
2018-03-03T22:33:24Z

From: Jaegeuk Kim <jaegeuk@kernel.org>

[ Upstream commit c13ff37e359bb3eacf4e1760dcea8d9760aa7459 ]

- has_not_enough_free_secs
node_secs: 0 dent_secs: 0 freed:0 free_segments:103 reserved:104

- f2fs_gc
- get_victim_by_default
alloc_mode 0, gc_mode 1, max_search 2672, offset 4654, ofs_unit 1

- do_garbage_collect
start_segno 3976, end_segno 3977 type 0

- is_alive
nid 22797, blkaddr 2131882, ofs_in_node 0, version 0x8/0x0

- gc_data_segment 766, segno 3976, block 512/426 not alive

So, this patch fixes subtle corrupted case where node version does not match
to summary version which results in infinite loop by gc.

Reported-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
fs/f2fs/gc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 34a69e7ed90b..17ab23f64bba 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -538,8 +538,10 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
get_node_info(sbi, nid, dni);

if (sum->version != dni->version) {
- f2fs_put_page(node_page, 1);
- return false;
+ f2fs_msg(sbi->sb, KERN_WARNING,
+ "%s: valid data with mismatched node version.",
+ __func__);
+ set_sbi_flag(sbi, SBI_NEED_FSCK);
}

*nofs = ofs_of_node(node_page);
--
2.14.1