Re: [PATCH v2] f2fs: avoid wrong decrypted data from disk

From: Jaegeuk Kim
Date: Wed Aug 29 2018 - 21:49:03 EST


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 <jaegeuk@xxxxxxxxxx>
---
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