[PATCH v3] F2FS: invalidate META_MAPPING before IPU/DIO write

[PATCH v3] F2FS: invalidate META_MAPPING before IPU/DIO write

[Hyeong-Jun Kim]

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>
---
 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)))
-- 
2.25.1

Re: [PATCH v3] F2FS: invalidate META_MAPPING before IPU/DIO write

[Chao Yu]

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,

>   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)))
> 

Re: [PATCH v3] F2FS: invalidate META_MAPPING before IPU/DIO write

[Hyeong-Jun Kim]

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?

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)))
> > 
> 
> 

Re: [PATCH v3] F2FS: invalidate META_MAPPING before IPU/DIO write

[Chao Yu]

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)))
>>>
>>
>>
>