Messages in this thread | | | Date | Tue, 2 Nov 2021 14:50:54 +0800 | Subject | Re: [PATCH v3] F2FS: invalidate META_MAPPING before IPU/DIO write | From | Chao Yu <> |
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On 2021/11/2 14:49, Hyeong-Jun Kim wrote: > On Tue, 2021-11-02 at 14:47 +0800, Chao Yu wrote: >> On 2021/11/2 12:59, Hyeong-Jun Kim wrote: >>> 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. >>> >>> --- >>> v3: >>> - Use sbi instead of fio->sbi in f2fs_inplace_write_data() >>> v2: >>> - Update patch description with race condition >> >> >> >>> Fixes: 6aa58d8ad20a ("f2fs: readahead encrypted block during GC") >>> Signed-off-by: Hyeong-Jun Kim < >>> hj514.kim@samsung.com >>>> >>> --- >> >> Change log should be attached here, otherwise Fixes & Signed-off-by >> tag will be lost >> after applying this patch. >> >> Thanks, >> > Thanks for your comment. > Should I re-send this patch?
Yes, please. :)
Thanks,
> > Thanks, >>> 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 74e1a350c1d8..9f754aaef558 100644 >>> --- a/fs/f2fs/data.c >>> +++ b/fs/f2fs/data.c >>> @@ -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; >>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >>> index 526423fe84ce..df9ed75f0b7a 100644 >>> --- a/fs/f2fs/segment.c >>> +++ b/fs/f2fs/segment.c >>> @@ -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))) >>> >> >> >
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