[PATCH 5.18 0926/1095] f2fs: fix to invalidate META_MAPPING before DIO write

Greg Kroah-Hartman
2022-08-15T23:04:48Z

From: Chao Yu <chao@kernel.org>

[ Upstream commit 67ca06872eb02944b4c6f92cffa9242e92c63109 ]

Quoted from commit e3b49ea36802 ("f2fs: invalidate META_MAPPING before
IPU/DIO write")

"
Encrypted pages during GC are read and cached in META_MAPPING.
However, due to cached pages in META_MAPPING, there is an issue where
newly written pages are lost by IPU or DIO writes.

Thread A - f2fs_gc() Thread B
/* phase 3 */
down_write(i_gc_rwsem)
ra_data_block() ---- (a)
up_write(i_gc_rwsem)
f2fs_direct_IO() :
- down_read(i_gc_rwsem)
- __blockdev_direct_io()
- get_data_block_dio_write()
- f2fs_dio_submit_bio() ---- (b)
- up_read(i_gc_rwsem)
/* phase 4 */
down_write(i_gc_rwsem)
move_data_block() ---- (c)
up_write(i_gc_rwsem)

(a) In phase 3 of f2fs_gc(), up-to-date page is read from storage and
cached in META_MAPPING.
(b) In thread B, writing new data by IPU or DIO write on same blkaddr as
read in (a). cached page in META_MAPPING become out-dated.
(c) In phase 4 of f2fs_gc(), out-dated page in META_MAPPING is copied to
new blkaddr. In conclusion, the newly written data in (b) is lost.

To address this issue, invalidating pages in META_MAPPING before IPU or
DIO write.
"

In previous commit, we missed to cover extent cache hit case, and passed
wrong value for parameter @end of invalidate_mapping_pages(), fix both
issues.

Fixes: 6aa58d8ad20a ("f2fs: readahead encrypted block during GC")
Fixes: e3b49ea36802 ("f2fs: invalidate META_MAPPING before IPU/DIO write")
Cc: Hyeong-Jun Kim <hj514.kim@samsung.com>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/data.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 9a1a526f2092..1862b03a9982 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1436,9 +1436,12 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
*map->m_next_extent = pgofs + map->m_len;

/* for hardware encryption, but to avoid potential issue in future */
- if (flag == F2FS_GET_BLOCK_DIO)
+ if (flag == F2FS_GET_BLOCK_DIO) {
f2fs_wait_on_block_writeback_range(inode,
map->m_pblk, map->m_len);
+ invalidate_mapping_pages(META_MAPPING(sbi),
+ map->m_pblk, map->m_pblk + map->m_len - 1);
+ }

if (map->m_multidev_dio) {
block_t blk_addr = map->m_pblk;
@@ -1655,7 +1658,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
f2fs_wait_on_block_writeback_range(inode,
map->m_pblk, map->m_len);
invalidate_mapping_pages(META_MAPPING(sbi),
- map->m_pblk, map->m_pblk);
+ map->m_pblk, map->m_pblk + map->m_len - 1);

if (map->m_multidev_dio) {
block_t blk_addr = map->m_pblk;
--
2.35.1