From: Chao Yu chao@kernel.org
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: Zizhi Wo wozizhi@huawei.com --- 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 5cdf4434ce11..1d4566a2d042 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1536,9 +1536,12 @@ 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); + } goto out; }
@@ -1719,7 +1722,7 @@ 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 (flag == F2FS_GET_BLOCK_PRECACHE) {