Re: [f2fs-dev] [PATCH v2] f2fs: avoid wrong decrypted data from disk
On 08/30, Chao Yu wrote:
> On 2018/8/30 9:48, Jaegeuk Kim wrote:
> > 1. Create a file in an encrypted directory
> > 2. Do GC & drop caches
> > 3. Read stale data before its bio for metapage was not issued yet
> >
> > Signed-off-by: Jaegeuk Kim
> > ---
> > Change log from v1:
> > - move to bio != NULL
> >
> > fs/f2fs/data.c | 6 ++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index 382c1ef9a9e4..159e411785e9 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -1556,6 +1556,12 @@ static int f2fs_mpage_readpages(struct address_space
> > *mapping,
> > bio = NULL;
> > goto set_error_page;
> > }
> > + } else if (unlikely(f2fs_encrypted_file(inode))) {
>
> For android scenario, encryption becomes a common case now, so I think we can
> remove unlikely here.
>
> > + /*
> > +* If the page is under writeback, we need to wait for
> > +* its completion to see the correct decrypted data.
> > +*/
> > + f2fs_wait_on_block_writeback(F2FS_I_SB(inode),
> > block_nr);
> > }
>
> Look at this again, it seems f2fs_wait_on_block_writeback() is not related to
> f2fs_grab_read_bio(), so we can move it here to make code logic more clear:
>
> if (f2fs_encrypted_file(inode)) {
> /* */
> f2fs_wait_on_block_writeback(F2FS_I_SB(inode), block_nr);
> }
>
> Also, in f2fs_submit_page_read(), we need to adjust to:
>
> - f2fs_grab_read_bio()
> - f2fs_wait_on_block_writeback()
> - bio_add_page()
>
> How do you think?
Oh, yeah!
>
> Thanks,
>
> >
> > if (bio_add_page(bio, page, blocksize, 0) < blocksize)
> >
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Re: [f2fs-dev] [PATCH v2] f2fs: avoid wrong decrypted data from disk
On 2018/8/30 9:48, Jaegeuk Kim wrote:
> 1. Create a file in an encrypted directory
> 2. Do GC & drop caches
> 3. Read stale data before its bio for metapage was not issued yet
>
> Signed-off-by: Jaegeuk Kim
> ---
> Change log from v1:
> - move to bio != NULL
>
> fs/f2fs/data.c | 6 ++
> 1 file changed, 6 insertions(+)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 382c1ef9a9e4..159e411785e9 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1556,6 +1556,12 @@ static int f2fs_mpage_readpages(struct address_space
> *mapping,
> bio = NULL;
> goto set_error_page;
> }
> + } else if (unlikely(f2fs_encrypted_file(inode))) {
For android scenario, encryption becomes a common case now, so I think we can
remove unlikely here.
> + /*
> + * If the page is under writeback, we need to wait for
> + * its completion to see the correct decrypted data.
> + */
> + f2fs_wait_on_block_writeback(F2FS_I_SB(inode),
> block_nr);
> }
Look at this again, it seems f2fs_wait_on_block_writeback() is not related to
f2fs_grab_read_bio(), so we can move it here to make code logic more clear:
if (f2fs_encrypted_file(inode)) {
/* */
f2fs_wait_on_block_writeback(F2FS_I_SB(inode), block_nr);
}
Also, in f2fs_submit_page_read(), we need to adjust to:
- f2fs_grab_read_bio()
- f2fs_wait_on_block_writeback()
- bio_add_page()
How do you think?
Thanks,
>
> if (bio_add_page(bio, page, blocksize, 0) < blocksize)
>
--
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Re: [f2fs-dev] [PATCH v2] f2fs: avoid wrong decrypted data from disk
1. Create a file in an encrypted directory
2. Do GC & drop caches
3. Read stale data before its bio for metapage was not issued yet
Signed-off-by: Jaegeuk Kim
---
Change log from v1:
- move to bio != NULL
fs/f2fs/data.c | 6 ++
1 file changed, 6 insertions(+)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 382c1ef9a9e4..159e411785e9 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1556,6 +1556,12 @@ static int f2fs_mpage_readpages(struct address_space
*mapping,
bio = NULL;
goto set_error_page;
}
+ } else if (unlikely(f2fs_encrypted_file(inode))) {
+ /*
+* If the page is under writeback, we need to wait for
+* its completion to see the correct decrypted data.
+*/
+ f2fs_wait_on_block_writeback(F2FS_I_SB(inode),
block_nr);
}
if (bio_add_page(bio, page, blocksize, 0) < blocksize)
--
2.17.0.441.gb46fe60e1d-goog
--
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