Commit e3b49ea3 authored by Hyeong-Jun Kim's avatar Hyeong-Jun Kim Committed by Jaegeuk Kim
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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.

Fixes: 6aa58d8a ("f2fs: readahead encrypted block during GC")
Signed-off-by: default avatarHyeong-Jun Kim <hj514.kim@samsung.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 10a26878

fs/f2fs/data.c

+2 −0
Original line number Diff line number Diff line
@@ -1708,6 +1708,8 @@ 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;

fs/f2fs/segment.c

+3 −0
Original line number Diff line number Diff line
@@ -3652,6 +3652,9 @@ 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)))