[PATCH 5.15 256/317] f2fs: invalidate META_MAPPING before IPU/DIO write

Sasha Levin
2024-03-24T23:39:08Z

From: Hyeong-Jun Kim <hj514.kim@samsung.com>

[ Upstream commit e3b49ea36802053f312013fd4ccb6e59920a9f76 ]

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.

Fixes: 6aa58d8ad20a ("f2fs: readahead encrypted block during GC")
Signed-off-by: Hyeong-Jun Kim <hj514.kim@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Stable-dep-of: fd244524c2cf ("f2fs: compress: fix to cover normal cluster write with cp_rwsem")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/data.c | 2 ++
fs/f2fs/segment.c | 3 +++
2 files changed, 5 insertions(+)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index e005f97fd273e..25dafd1261d71 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1711,6 +1711,8 @@ 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);

if (map->m_multidev_dio) {
block_t blk_addr = map->m_pblk;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 25d53617a50e6..5eca50e50e16b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3622,6 +3622,9 @@ int f2fs_inplace_write_data(struct f2fs_io_info *fio)
goto drop_bio;
}

+ invalidate_mapping_pages(META_MAPPING(sbi),
+ fio->new_blkaddr, fio->new_blkaddr);
+
stat_inc_inplace_blocks(fio->sbi);

if (fio->bio && !(SM_I(sbi)->ipu_policy & (1 << F2FS_IPU_NOCACHE)))
--
2.43.0