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
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 382c1ef..8c204f8 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -565,9 +565,6 @@
ctx->bio = bio;
ctx->enabled_steps = post_read_steps;
bio->bi_private = ctx;
-
- /* wait the page to be moved by cleaning */
- f2fs_wait_on_block_writeback(sbi, blkaddr);
}
return bio;
@@ -582,6 +579,9 @@
if (IS_ERR(bio))
return PTR_ERR(bio);
+ /* wait for GCed page writeback via META_MAPPING */
+ f2fs_wait_on_block_writeback(inode, blkaddr);
+
if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
bio_put(bio);
return -EFAULT;
@@ -1558,6 +1558,12 @@
}
}
+ /*
+ * If the page is under writeback, we need to wait for
+ * its completion to see the correct decrypted data.
+ */
+ f2fs_wait_on_block_writeback(inode, block_nr);
+
if (bio_add_page(bio, page, blocksize, 0) < blocksize)
goto submit_and_realloc;
@@ -1625,7 +1631,7 @@
return 0;
/* wait for GCed page writeback via META_MAPPING */
- f2fs_wait_on_block_writeback(fio->sbi, fio->old_blkaddr);
+ f2fs_wait_on_block_writeback(inode, fio->old_blkaddr);
retry_encrypt:
fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
@@ -2382,10 +2388,6 @@
f2fs_wait_on_page_writeback(page, DATA, false);
- /* wait for GCed page writeback via META_MAPPING */
- if (f2fs_post_read_required(inode))
- f2fs_wait_on_block_writeback(sbi, blkaddr);
-
if (len == PAGE_SIZE || PageUptodate(page))
return 0;